View source for Biology:Genetically modified crops

{{Short description|Plants used in agriculture}}
{{Genetic engineering sidebar}}
'''Genetically modified crops''' ('''GM crops''') are plants used in [[Earth:Agriculture|agriculture]], the [[Biology:DNA|DNA]] of which has been modified using [[Biology:Genetic engineering|genetic engineering]] methods. Plant [[Biology:Genome|genomes]] can be engineered by physical methods or by use of ''[[Biology:Agrobacterium|Agrobacterium]]'' for the delivery of sequences hosted in [[Biology:Transfer DNA binary system|T-DNA binary vectors]]. In most cases, the aim is to introduce a new trait to the plant which does not occur naturally in the species. Examples in food crops include resistance to certain pests, diseases, environmental conditions, reduction of spoilage, resistance to chemical treatments (e.g. resistance to a [[Biology:Herbicide|herbicide]]), or improving the nutrient profile of the crop. Examples in non-food crops include production of pharmaceutical agents, biofuels, and other industrially useful goods, as well as for [[Earth:Bioremediation|bioremediation]].<ref name="James2013">{{cite web | title = ISAAA 2013 Annual Report | url = http://www.isaaa.org/resources/publications/briefs/46/executivesummary/ | quote = Executive Summary, Global Status of Commercialized Biotech/GM Crops | date = 2013 | work = ISAAA Brief 46-2013 | access-date = 6 August 2014 }}</ref>

Farmers have widely adopted GM technology. Acreage increased from 1.7 million hectares in 1996 to 185.1 million hectares in 2016, some 12% of global cropland. As of 2016, major crop ([[Biology:Soybean|soybean]], [[Biology:Maize|maize]], canola and [[Biology:Cotton|cotton]]) traits consist of herbicide tolerance (95.9 million hectares) insect resistance (25.2 million hectares), or both (58.5 million hectares). In 2015, 53.6 million ha of Genetically modified maize were under cultivation (almost 1/3 of the maize crop). GM maize outperformed its predecessors: yield was 5.6 to 24.5% higher with less [[Chemistry:Mycotoxin|mycotoxin]]s (−28.8%), [[Chemistry:Fumonisin B1|fumonisin]] (−30.6%) and thricotecens (−36.5%). Non-target organisms were unaffected, except for lower populations some [[Biology:Parasitoid|parasitoid]] wasps due to decreased populations of their pest host [[Biology:European corn borer|European corn borer]]; European corn borer is a target of ''[[Biology:Lepidoptera|Lepidoptera]]'' active Bt maize. Biogeochemical parameters such as lignin content did not vary, while biomass decomposition was higher.<ref name="Pellegrino_2018">{{cite journal | vauthors = Pellegrino E, Bedini S, Nuti M, Ercoli L | title = Impact of genetically engineered maize on agronomic, environmental and toxicological traits: a meta-analysis of 21 years of field data | language = En | journal = Scientific Reports | volume = 8 | issue = 1 | pages = 3113 | date = February 2018 | pmid = 29449686 | pmc = 5814441 | doi = 10.1038/s41598-018-21284-2 | bibcode = 2018NatSR...8.3113P }}</ref>

A 2014 meta-analysis concluded that GM technology adoption had reduced chemical [[Biology:Pesticide|pesticide]] use by 37%, increased crop yields by 22%, and increased farmer profits by 68%.<ref name="KlumperQaim" /> This reduction in pesticide use has been ecologically beneficial, but benefits may be reduced by overuse.<ref name="nytimes.com">{{cite web | vauthors = Pollack A | work = {{wipe|The New York Times}} | date = 13 April 2010 | url = https://www.nytimes.com/2010/04/14/business/energy-environment/14crop.html?pagewanted=all&_r=0 | title = Study Says Overuse Threatens Gains From Modified Crops }}</ref> Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops.<ref name="perry">{{cite journal | vauthors = Perry ED, Ciliberto F, Hennessy DA, Moschini G | title = Genetically engineered crops and pesticide use in U.S. maize and soybeans | journal = Science Advances | volume = 2 | issue = 8 | pages = e1600850 | date = August 2016 | pmid = 27652335 | pmc = 5020710 | doi = 10.1126/sciadv.1600850 | bibcode = 2016SciA....2E0850P }}</ref> Yield and profit gains are higher in developing countries than in developed countries.<ref name="KlumperQaim" /> [[Medicine:Pesticide poisoning|Pesticide poisoning]]s were reduced by 2.4 to 9  million cases per year in India alone.<ref name="Smyth">{{cite journal |last1=Smyth |first1=Stuart J. |title=The human health benefits from GM crops |journal=Plant Biotechnology Journal |date=April 2020 |volume=18 |issue=4 |pages=887–888 |doi=10.1111/pbi.13261|pmid=31544299 |pmc=7061863 }}</ref> A 2011 review of the relationship between Bt cotton adoption and farmer suicides in India found that "Available data show no evidence of a 'resurgence' of farmer suicides" and that "Bt cotton technology has been very effective overall in India."<ref>{{Cite journal | last1 = Gruère | first1 = G. | last2 = Sengupta | first2 = D. | s2cid = 20145281 | doi = 10.1080/00220388.2010.492863 | title = Bt Cotton and Farmer Suicides in India: An Evidence-based Assessment | journal = Journal of Development Studies | volume = 47 | issue = 2 | pages = 316–337 | year = 2011 | pmid =  21506303}}</ref> During the time period of Bt cotton introduction in India, farmer suicides instead declined by 25%.<ref name="Smyth"/>

<!-- The following language and sources, per WP:GMORfC, must not be altered without achieving consensus-->There is a [[Philosophy:Scientific consensus|scientific consensus]]<ref name="Nicolia2013"/><ref name="FAO"/><ref name="Ronald2011"/><ref name="Also"/> that currently available food derived from GM crops poses no greater risk to human health than conventional food,<ref name="AAAS2012"/><ref name="ECom2010"/><ref name="AMA2001"/><ref name="LoC2015"/><ref name="NAS2016"/> but that each GM food needs to be tested on a case-by-case basis before introduction.<ref name="WHOFAQ"/><ref name="Haslberger2003"/><ref name="BMA2004"/> Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.<ref name="PEW2015"/><ref name="Marris2001"/><ref name="PABE"/><ref name="Scott2016"/> The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.<ref name="loc.gov"/><ref name="Bashshur"/><ref name="Sifferlin"/><ref name="Council on Foreign Relations"/><!--End of restricted section -->

However, opponents have objected to GM crops on grounds including environmental impacts, food safety, whether GM crops are needed to address food needs, whether they are sufficiently accessible to farmers in developing countries<ref name="Azadi_2016">{{cite journal | vauthors = Azadi H, Samiee A, Mahmoudi H, Jouzi Z, Khachak PR, De Maeyer P, Witlox F | title = Genetically modified crops and small-scale farmers: main opportunities and challenges | journal = Critical Reviews in Biotechnology | volume = 36 | issue = 3 | pages = 434–46 | date = 2016 | pmid = 25566797 | doi = 10.3109/07388551.2014.990413 | s2cid = 46117952 | url = https://biblio.ugent.be/publication/7022459 | hdl = 1854/LU-7022459 | hdl-access = free }}</ref> and concerns over subjecting crops to [[Social:Intellectual property|intellectual property]] law. Safety concerns led 38 countries, including 19 in Europe, to officially prohibit their cultivation.<ref name="Pellegrino_2018" />
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==History==
{{Main|Biology:History of genetic engineering}}
Humans have directly influenced the genetic makeup of plants to increase their value as a crop through domestication. The first evidence of plant domestication comes from [[Biology:Emmer|emmer]] and [[Biology:Einkorn wheat|einkorn wheat]] found in pre-Pottery Neolithic A villages in Southwest Asia dated about 10,500 to 10,100 BC.<ref>{{cite book | vauthors = Zohary D, Hopf M, Weiss E |title=Domestication of Plants in the Old World: The Origin and Spread of Domesticated Plants in Southwest Asia, Europe, and the Mediterranean Basin|url={{google books |plainurl=y |id=tc6vr0qzk_4C}}|date=1 March 2012|publisher=OUP Oxford|isbn=978-0-19-954906-1 | page = 1 }}</ref>  The [[Place:Fertile Crescent|Fertile Crescent]] of Western Asia, Egypt, and India were sites of the earliest planned sowing and harvesting of plants that had previously been gathered in the wild. Independent development of agriculture occurred in northern and southern China, Africa's [[Place:Sahel|Sahel]], New Guinea and several regions of the Americas.<ref>{{cite web | url = https://www.nytimes.com/2010/05/25/science/25creature.html?_r=1 | title = The history of maize cultivation in southern Mexico dates back 9,000 years. | work = The New York Times | date = 25 May 2010 }}</ref> The eight Neolithic founder crops (emmer wheat, [[Biology:Einkorn wheat|einkorn wheat]], [[Biology:Barley|barley]], peas, lentils, [[Biology:Vicia ervilia|bitter vetch]], chick peas and [[Biology:Flax|flax]]) had all appeared by about 7,000 BC.<ref>{{cite book|title=The Origins and Spread of Domestic Plants in Southwest Asia and Europe| vauthors = Colledge S, Conolly J |isbn=978-1598749885|page=[https://archive.org/details/originsspreadofd0000unse/page/40 40]|year=2007| publisher = Left Coast Press |url=https://archive.org/details/originsspreadofd0000unse/page/40}}</ref> Traditional crop breeders have long introduced foreign [[Biology:Germplasm|germplasm]] into crops by creating novel crosses. A [[Biology:Hybrid|hybrid]] [[Biology:Cereal|cereal]] grain was created in 1875, by crossing [[Biology:Genetically modified wheat|wheat]] and [[Biology:Rye|rye]].<ref>{{cite journal | vauthors = Chen ZJ | title = Molecular mechanisms of polyploidy and hybrid vigor | journal = Trends in Plant Science | volume = 15 | issue = 2 | pages = 57–71 | date = February 2010 | pmid = 20080432 | pmc = 2821985 | doi = 10.1016/j.tplants.2009.12.003 }}</ref> Since then traits including dwarfing genes and [[Biology:Plant disease resistance|rust resistance]] have been introduced in that manner.<ref>{{cite journal | vauthors = Hoisington D, Khairallah M, Reeves T, Ribaut JM, Skovmand B, Taba S, Warburton M | title = Plant genetic resources: what can they contribute toward increased crop productivity? | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 96 | issue = 11 | pages = 5937–43 | date = May 1999 | pmid = 10339521 | pmc = 34209 | doi = 10.1073/pnas.96.11.5937 | bibcode = 1999PNAS...96.5937H | doi-access = free }}</ref> [[Biology:Plant tissue culture|Plant tissue culture]] and deliberate [[Biology:Mutation|mutation]]s have enabled humans to alter the makeup of plant genomes.<ref>{{cite journal| vauthors  = Predieri S  |s2cid=37850239 |year=2001 |title=Mutation induction and tissue culture in improving fruits|journal=Plant Cell, Tissue and Organ Culture|volume=64|issue=2/3|pages=185–210|doi=10.1023/A:1010623203554}}</ref><ref>{{cite book| vauthors = Duncan R |title=Advances in Agronomy Volume 58 |year=1996|chapter=Tissue Culture-Induced Variation and Crop Improvement|volume=58|pages=201–40|doi=10.1016/S0065-2113(08)60256-4|isbn=9780120007585}}</ref>

Modern advances in genetics have allowed humans to more directly alter plants genetics.  In 1970 [[Biography:Hamilton O. Smith|Hamilton Smith's]] lab discovered restriction enzymes that allowed DNA to be cut at specific places, enabling scientists to isolate genes from an organism's genome.<ref>{{cite journal | vauthors = Roberts RJ | title = How restriction enzymes became the workhorses of molecular biology | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 102 | issue = 17 | pages = 5905–8 | date = April 2005 | pmid = 15840723 | pmc = 1087929 | doi = 10.1073/pnas.0500923102 | bibcode = 2005PNAS..102.5905R | doi-access = free }}</ref> [[Biology:DNA ligase|DNA ligase]]s that join broken DNA together had been discovered earlier in 1967,<ref name="WeissRichardson1967">{{cite journal | vauthors = Weiss B, Richardson CC | title = Enzymatic breakage and joining of deoxyribonucleic acid, I. Repair of single-strand breaks in DNA by an enzyme system from Escherichia coli infected with T4 bacteriophage | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 57 | issue = 4 | pages = 1021–8 | date = April 1967 | pmid = 5340583 | pmc = 224649 | doi = 10.1073/pnas.57.4.1021 | bibcode = 1967PNAS...57.1021W | doi-access = free }}</ref> and by combining the two technologies, it was possible to "cut and paste" DNA sequences and create [[Biology:Recombinant DNA|recombinant DNA]]. [[Biology:Plasmid|Plasmid]]s, discovered in 1952,<ref>{{cite journal | vauthors = Lederberg J | title = Cell genetics and hereditary symbiosis | journal = Physiological Reviews | volume = 32 | issue = 4 | pages = 403–30 | date = October 1952 | pmid = 13003535 | doi = 10.1152/physrev.1952.32.4.403 | url = http://profiles.nlm.nih.gov/ps/access/BBABFO.pdf }}</ref> became important [[Biology:Vector (molecular biology)|tools]] for transferring information between cells and [[Biology:Molecular cloning|replicating]] DNA sequences. In 1907 a bacterium that caused plant tumors, ''[[Biology:Agrobacterium tumefaciens|Agrobacterium tumefaciens]]'', was discovered and in the early 1970s the tumor inducing agent was found to be a DNA plasmid called the [[Biology:Ti plasmid|Ti plasmid]].<ref>{{cite web | vauthors = Nester E | title = ''Agrobacterium'': The Natural Genetic Engineer (100 Years Later) | url = http://www.apsnet.org/publications/apsnetfeatures/Pages/Agrobacterium.aspx | date = 2008 | access-date = 5 October 2012 | archive-url = https://web.archive.org/web/20121019164906/http://www.apsnet.org/publications/apsnetfeatures/Pages/Agrobacterium.aspx | archive-date = 19 October 2012 | url-status = dead }}</ref> By removing the genes in the plasmid that caused the tumor and adding in novel genes researchers were able to infect plants with ''A. tumefaciens'' and let the bacteria insert their chosen DNA sequence into the genomes of the plants.<ref>{{cite journal | vauthors = Zambryski P, Joos H, Genetello C, Leemans J, Montagu MV, Schell J | title = Ti plasmid vector for the introduction of DNA into plant cells without alteration of their normal regeneration capacity | journal = The EMBO Journal | volume = 2 | issue = 12 | pages = 2143–50 | year = 1983 | pmid = 16453482 | pmc = 555426 | doi = 10.1002/j.1460-2075.1983.tb01715.x }}</ref> As not all plant cells were susceptible to infection by ''A. tumefaciens'' other methods were developed, including [[Biology:Electroporation|electroporation]], [[Biology:Microinjection|micro-injection]]<ref>{{cite web | vauthors = Peters P | title = Transforming Plants – Basic Genetic Engineering Techniques | url = http://www.accessexcellence.org/RC/AB/BA/Transforming_Plants.php | access-date = 28 January 2010 | url-status = dead | archive-url = https://web.archive.org/web/20100316174245/http://www.accessexcellence.org/RC/AB/BA/Transforming_Plants.php | archive-date = 16 March 2010 }}</ref> and particle bombardment with a gene gun (invented in 1987).<ref>{{cite web| vauthors = Voiland M, McCandless L |title=Development Of The "Gene Gun" At Cornell |url=http://www.nysaes.cornell.edu/pubs/press/1999/genegun.html |date=February 1999 |url-status=dead |archive-url=https://web.archive.org/web/20080501203428/http://www.nysaes.cornell.edu/pubs/press/1999/genegun.html |archive-date=1 May 2008 }}</ref><ref>{{cite journal| vauthors = Segelken R |journal=Cornell Chronicle|date= 14 May 1987|title=Biologists Invent Gun for Shooting Cells with DNA Issue |url=http://ecommons.cornell.edu/bitstream/1813/25239/1/018_33.pdf |page =3|volume=18|issue=33}}</ref> In the 1980s techniques were developed to introduce isolated chloroplasts back into a plant cell that had its cell wall removed. With the introduction of the gene gun in 1987 it became possible to integrate foreign genes into a [[Biology:Chloroplast|chloroplast]].<ref>{{cite web | url = http://www.lifesciencesfoundation.org/events-item-799.html | title = Timelines: 1987: Next The gene gun | work = lifesciencesfoundation.org | archive-url = https://web.archive.org/web/20130330150255/http://www.lifesciencesfoundation.org/events-item-799.html | archive-date = 30 March 2013 }}</ref> Genetic transformation has become very efficient in some model organisms. In 2008 genetically modified seeds were produced in ''Arabidopsis thaliana'' by dipping the flowers in an ''Agrobacterium'' solution.<ref>{{cite journal | vauthors = Clough SJ, Bent AF | title = Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana | journal = The Plant Journal | volume = 16 | issue = 6 | pages = 735–43 | date = December 1998 | pmid = 10069079 | doi = 10.1046/j.1365-313x.1998.00343.x | s2cid = 410286 }}</ref> In 2013 [[Biology:CRISPR|CRISPR]] was first used to target modification of plant genomes.<ref name="pmid23999092">{{cite journal | vauthors = Jiang W, Zhou H, Bi H, Fromm M, Yang B, Weeks DP | title = Demonstration of CRISPR/Cas9/sgRNA-mediated targeted gene modification in Arabidopsis, tobacco, sorghum and rice | journal = Nucleic Acids Research | volume = 41 | issue = 20 | pages = e188 | date = November 2013 | pmid = 23999092 | pmc = 3814374 | doi = 10.1093/nar/gkt780 }}</ref>

The first genetically engineered crop plant was tobacco, reported in 1983.<ref>{{cite journal | vauthors = Lemaux PG | title = Genetically Engineered Plants and Foods: A Scientist's Analysis of the Issues (Part I) | journal = Annual Review of Plant Biology | volume = 59 | pages = 771–812 | year = 2008 | pmid = 18284373 | doi = 10.1146/annurev.arplant.58.032806.103840 }}</ref> It was developed creating a [[Biology:Chimeric gene|chimeric gene]] that joined an antibiotic resistant gene to the T1 plasmid from ''Agrobacterium''. The tobacco was infected with ''Agrobacterium'' transformed with this plasmid resulting in the chimeric gene being inserted into the plant. Through [[Biology:Tissue culture|tissue culture]] techniques a single tobacco cell was selected that contained the gene and a new plant grown from it.<ref>{{cite journal | vauthors = Bevan MW, Flavell RB, Chilton MD | s2cid = 28713537 | title = A chimaeric antibiotic resistance gene as a selectable marker for plant cell transformation. 1983 | journal = Biotechnology | volume = 24 | issue = 5922 | pages = 367–70 | year = 1983 | pmid = 1422041 | doi = 10.1038/304184a0 | bibcode = 1983Natur.304..184B |  author-link3 = Mary-Dell Chilton }}</ref>  The first field trials of genetically engineered plants occurred in France and the US in 1986, tobacco plants were engineered to be resistant to [[Biology:Herbicide|herbicide]]s.<ref name="James 1996">{{cite web| vauthors = James C |title=Global Review of the Field Testing and Commercialization of Transgenic Plants: 1986 to 1995|url=http://www.isaaa.org/kc/Publications/pdfs/isaaabriefs/Briefs%201.pdf|publisher=The International Service for the Acquisition of Agri-biotech Applications|access-date=17 July 2010|year=1996}}</ref> In 1987 [[Company:Plant Genetic Systems|Plant Genetic Systems]], founded by Marc Van Montagu and Jeff Schell, was the first company to genetically engineer insect-resistant plants by incorporating genes that produced insecticidal proteins from [[Biology:Bacillus thuringiensis|Bacillus thuringiensis]] (Bt) into [[Biology:Tobacco|tobacco]].<ref>{{cite journal | vauthors = Vaeck M, Reynaerts A, Höfte H, Jansens S, De Beuckeleer M, Dean C, Zabeau M, Van Montagu M, Leemans J | display-authors = 6 |doi=10.1038/328033a0 |bibcode=1987Natur.328...33V |title= Transgenic plants protected from insect attack|journal=Nature|volume=328|issue=6125|pages=33–37|year=1987 |s2cid=4310501}}
</ref> The People's Republic of China was the first country to commercialise transgenic plants, introducing a virus-resistant tobacco in 1992.<ref name="James1997">{{cite journal| vauthors = James C |year=1997|title=Global Status of Transgenic Crops in 1997|journal=ISAAA Briefs No. 5|page=31|url=http://www.isaaa.org/resources/publications/briefs/05/download/isaaa-brief-05-1997.pdf}}</ref> In 1994 Calgene attained approval to commercially release the [[Biology:Flavr Savr|Flavr Savr]] tomato, a tomato engineered to have a longer shelf life.<ref name="doi10.3733/ca.v054n04p6"/> Also in 1994, the European Union approved tobacco engineered to be resistant to the herbicide [[Chemistry:Bromoxynil|bromoxynil]], making it the first genetically engineered crop commercialised in Europe.<ref>{{cite magazine|title=Transgenic tobacco is European first|date=18 June 1994| vauthors = MacKenzie D |url= https://www.newscientist.com/article/mg14219301.100-transgenic-tobacco-is-european-first.html |magazine=New Scientist}}</ref> In 1995 Bt Potato was approved safe by the Environmental Protection Agency, after having been approved by the FDA, making it the first pesticide producing crop to be approved in the US.<ref>{{cite web | url = https://news.google.com/newspapers?id=A0YyAAAAIBAJ&pg=4631,1776980&dq=bacillus+thuringiensis+potato+1996+approved&hl= | title = Genetically Altered Potato Ok'd For Crops | work = Lawrence Journal | date = 6 May 1995 }}</ref> In 1996 a total of 35 approvals had been granted to commercially grow 8 transgenic crops and one flower crop (carnation), with 8 different traits in 6 countries plus the EU.<ref name="James 1996"/> By 2010, 29 countries had planted commercialised genetically modified crops and a further 31 countries had granted regulatory approval for transgenic crops to be imported.<ref name="James2011" />

The first genetically modified animal to be commercialised was the [[Biology:GloFish|GloFish]], a [[Biology:Zebrafish|Zebra fish]] with a fluorescent gene added that allows it to glow in the dark under ultraviolet light.<ref>{{cite journal | vauthors = Vàzquez-Salat N, Salter B, Smets G, Houdebine LM | title = The current state of GMO governance: are we ready for GM animals? | journal = Biotechnology Advances | volume = 30 | issue = 6 | pages = 1336–43 | date = 1 November 2012 | pmid = 22361646 | doi = 10.1016/j.biotechadv.2012.02.006 | series = Special issue on ACB 2011 }}</ref> The first genetically modified animal to be approved for food use was AquAdvantage salmon in 2015.<ref>{{cite journal|title=Aquabounty Cleared to Sell Salmon in USA for Commercial Purposes |journal=FDA|url=https://www.fda.gov/AnimalVeterinary/DevelopmentApprovalProcess/GeneticEngineering/GeneticallyEngineeredAnimals/ucm280853.htm|date=25 April 2019}}</ref> The salmon were transformed with a [[Biology:Growth hormone|growth hormone]]-regulating gene from a [[Biology:Chinook salmon|Pacific Chinook salmon]] and a promoter from an [[Biology:Ocean pout|ocean pout]] enabling it to grow year-round instead of only during spring and summer.<ref>{{cite web|url = https://www.aquabounty.com/wp-content/uploads/2014/02/Risk_Assessment_Mitigation_of_AAS-Oct2010.pdf|title = Risk Assessment and Mitigation of AquAdvantage Salmon|date = October 2010|publisher = ISB News Report|vauthors = Bodnar A|access-date = 7 November 2019|archive-date = 8 March 2021|archive-url = https://web.archive.org/web/20210308125138/https://aquabounty.com/wp-content/uploads/2014/02/Risk_Assessment_Mitigation_of_AAS-Oct2010.pdf|url-status = dead}}</ref>

==Methods==
{{Main|Biology:Genetic engineering techniques}}

[[File:Transformation with Agrobacterium.JPG|thumb|Plants (''Solanum chacoense'') being transformed using agrobacterium]]
Genetically engineered crops have genes added or removed using [[Biology:Genetic engineering|genetic engineering]] techniques,<ref>{{cite web | vauthors = Boyle R | work = Popular Science | date = 24 January 2011 | url = http://www.popsci.com/science/article/2011-01/life-cycle-genetically-modified-seed?single-page-view=true | title = How To Genetically Modify a Seed, Step By Step }}</ref> originally including [[Biology:Gene gun|gene gun]]s, [[Biology:Electroporation|electroporation]], [[Biology:Microinjection|microinjection]] and [[Biology:Agrobacterium|agrobacterium]]. More recently, [[Biology:CRISPR|CRISPR]] and [[Biology:Transcription activator-like effector nuclease|TALEN]] offered much more precise and convenient editing techniques.

Gene guns (also known as biolistics) "shoot" (direct high energy particles or radiations against<ref>{{cite web|url=http://dictionary.reference.com/browse/bombarded|title=Bombarded - Define Bombarded at Dictionary.com|work=Dictionary.com}}</ref>) target genes into plant cells. It is the most common method. [[Biology:DNA|DNA]] is bound to tiny particles of gold or tungsten which are subsequently shot into plant tissue or single plant cells under high pressure. The accelerated particles penetrate both the [[Biology:Cell wall|cell wall]] and [[Biology:Cell membrane|membranes]]. The DNA separates from the metal and is integrated into plant DNA inside the [[Biology:Cell nucleus|nucleus]]. This method has been applied successfully for many cultivated crops, especially monocots like wheat or maize, for which [[Biology:Transformation (genetics)|transformation]] using ''Agrobacterium tumefaciens'' has been less successful.<ref>{{cite journal | vauthors = Shrawat AK, Lörz H | title = Agrobacterium-mediated transformation of cereals: a promising approach crossing barriers | journal = Plant Biotechnology Journal | volume = 4 | issue = 6 | pages = 575–603 | date = November 2006 | pmid = 17309731 | doi = 10.1111/j.1467-7652.2006.00209.x | doi-access = free }}</ref> The major disadvantage of this procedure is that serious damage can be done to the cellular tissue.

''[[Biology:Agrobacterium tumefaciens|Agrobacterium tumefaciens]]-''mediated transformation is another common technique. Agrobacteria are natural plant parasites.<ref name="Halford">{{cite book|title=Genetically modified crops | vauthors = Halford NG |date=2012|publisher=Imperial College Press|others=World Scientific (Firm)|isbn=978-1848168381|edition=2nd|location=London|oclc=785724094}}</ref> Their natural ability to transfer genes provides another engineering method. To create a suitable environment for themselves, these Agrobacteria insert their genes into plant hosts, resulting in a proliferation of modified plant cells near the soil level (crown gall). The genetic information for tumor growth is encoded on a mobile, circular DNA fragment ([[Biology:Plasmid|plasmid]]). When ''Agrobacterium'' infects a plant, it transfers this [[Biology:Ti plasmid|T-DNA]] to a random site in the plant genome. When used in genetic engineering the bacterial T-DNA is removed from the bacterial plasmid and replaced with the desired foreign gene. The bacterium is a [[Biology:Vector (epidemiology)|vector]], enabling transportation of foreign genes into plants. This method works especially well for [[Biology:Dicotyledon|dicotyledon]]ous plants like potatoes, tomatoes, and tobacco. Agrobacteria infection is less successful in crops like wheat and maize.

Electroporation is used when the plant tissue does not contain cell walls. In this technique, "DNA enters the plant cells through miniature pores which are temporarily caused by electric pulses."

Microinjection is used to directly inject foreign DNA into cells.<ref>{{cite journal | vauthors = Maghari BM, Ardekani AM | title = Genetically modified foods and social concerns | journal = Avicenna Journal of Medical Biotechnology | volume = 3 | issue = 3 | pages = 109–17 | date = July 2011 | pmid = 23408723 | pmc = 3558185 }}</ref>

Plant scientists, backed by results of modern comprehensive profiling of crop composition, point out that crops modified using GM techniques are less likely to have unintended changes than are conventionally bred crops.<ref>{{Cite web|url=http://www.isb.vt.edu/news/2006/news06.jan.htm#jan0603|title=Information Systems for Biotechnology News Report}}</ref><ref>{{cite journal | vauthors = Catchpole GS, Beckmann M, Enot DP, Mondhe M, Zywicki B, Taylor J, Hardy N, Smith A, King RD, Kell DB, Fiehn O, Draper J | display-authors = 6 | title = Hierarchical metabolomics demonstrates substantial compositional similarity between genetically modified and conventional potato crops | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 102 | issue = 40 | pages = 14458–62 | date = October 2005 | pmid = 16186495 | pmc = 1242293 | doi = 10.1073/pnas.0503955102 | url = http://cadair.aber.ac.uk/dspace/bitstream/2160/4228/2/hierarchical%20metabolomics%20demonstrates%20substantial%20compositional%20similarity%20between%20genetically%20modified%20and%20conventional%20potato%20crops.pdf | bibcode = 2005PNAS..10214458C | doi-access = free }}{{Dead link|date=July 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

In research [[Biology:Tobacco|tobacco]] and ''[[Biology:Arabidopsis thaliana|Arabidopsis thaliana]]'' are the most frequently modified plants, due to well-developed transformation methods, easy propagation and well studied genomes.<ref>{{cite journal | vauthors = Koornneef M, Meinke D | title = The development of Arabidopsis as a model plant | journal = The Plant Journal | volume = 61 | issue = 6 | pages = 909–21 | date = March 2010 | pmid = 20409266 | doi = 10.1111/j.1365-313X.2009.04086.x | doi-access = free }}</ref><ref name = banjara>{{cite journal|title=Expression of an Arabidopsis sodium/proton antiporter gene (AtNHX1) in peanut to improve salt tolerance |date=1 January 2012 |doi=10.1007/s11816-011-0200-5 |volume=6 |journal=Plant Biotechnology Reports |pages=59–67| vauthors = Banjara M, Zhu L, Shen G, Payton P, Zhang H |s2cid=12025029 }}</ref> They serve as model organisms for other plant species.

Introducing new genes into plants requires a [[Biology:Promoter (genetics)|promoter]] specific to the area where the gene is to be expressed. For instance, to express a gene only in rice grains and not in leaves, an [[Biology:Endosperm|endosperm]]-specific promoter is used. The codons of the gene must be optimized for the organism due to [[Biology:Codon usage bias|codon usage bias]].

== Types of modifications ==
[[File:Btcornafrica.jpg|thumb|Transgenic maize containing a gene from the bacteria ''Bacillus thuringiensis'']]

=== Transgenic ===
Transgenic plants have genes inserted into them that are derived from another species. The inserted genes can come from species within the same [[Biology:Kingdom|kingdom]] (plant to plant), or between kingdoms (for example, bacteria to plant). In many cases the inserted DNA has to be modified slightly in order to be correctly and efficiently [[Biology:Gene expression|expressed]] in the host organism. Transgenic plants are used to express [[Biology:Proteins|proteins]], like the [[Biology:Delta endotoxin|cry toxins]] from ''B. thuringiensis'', [[Biology:Herbicide|herbicide]]-resistant genes, [[Biology:Antibodies|antibodies]],<ref>{{cite web|url=https://www.theguardian.com/science/2001/sep/09/gm.food|title=GM corn set to stop man spreading his seed| vauthors = McKie R |work=the Guardian|date=9 September 2001}}</ref> and antigens for [[Biology:Vaccination|vaccination]]s.<ref>{{cite journal | vauthors = Walmsley AM, Arntzen CJ | title = Plants for delivery of edible vaccines | journal = Current Opinion in Biotechnology | volume = 11 | issue = 2 | pages = 126–9 | date = April 2000 | pmid = 10753769 | doi = 10.1016/S0958-1669(00)00070-7 }}</ref> A study led by the European Food Safety Authority (EFSA) also found viral genes in transgenic plants.<ref>{{cite journal | vauthors = Podevin N, du Jardin P | title = Possible consequences of the overlap between the CaMV 35S promoter regions in plant transformation vectors used and the viral gene VI in transgenic plants | journal = GM Crops & Food | volume = 3 | issue = 4 | pages = 296–300 | year = 2012 | pmid = 22892689 | doi = 10.4161/gmcr.21406 | doi-access = free }}</ref>

Transgenic carrots have been used to produce the drug [[Chemistry:Taliglucerase alfa|Taliglucerase alfa]] which is used to treat [[Medicine:Gaucher's disease|Gaucher's disease]].<ref>{{cite web | vauthors = Maxmen A | date = 2 May 2012 | url = http://blogs.nature.com/news/2012/05/first-plant-made-drug-on-the-market.html | title = First plant-made drug on the market | work = Nature, Biology & Biotechnology, Industry | access-date = 1 September 2012 | archive-date = 18 October 2012 | archive-url = https://web.archive.org/web/20121018222214/http://blogs.nature.com/news/2012/05/first-plant-made-drug-on-the-market.html | url-status = dead }}</ref> In the laboratory, transgenic plants have been modified to increase [[Earth:Photosynthesis|photosynthesis]] (currently about 2% at most plants versus the theoretic potential of 9–10%).<ref>NWT magazine, April 2011</ref> This is possible by changing the rubisco enzyme (i.e. changing [[Biology:C3 carbon fixation|C<sub>3</sub>]] plants into [[Biology:C4 carbon fixation|C<sub>4</sub>]] plants<ref>{{cite web | vauthors = Hibberd J | url = http://www.plantsci.cam.ac.uk/research/julianhibberd.html | title = Molecular Physiology | work = Department of Plant Sciences | publisher = University of Cambridge | access-date = 1 September 2012 | archive-date = 17 May 2013 | archive-url = https://web.archive.org/web/20130517035704/http://www.plantsci.cam.ac.uk/research/julianhibberd.html | url-status = dead }}</ref>), by placing the rubisco in a [[Biology:Carboxysome|carboxysome]], by adding {{CO2}} pumps in the cell wall,<ref name="pmid17578868">{{cite journal | vauthors = Price GD, Badger MR, Woodger FJ, Long BM | title = Advances in understanding the cyanobacterial CO2-concentrating-mechanism (CCM): functional components, Ci transporters, diversity, genetic regulation and prospects for engineering into plants | journal = Journal of Experimental Botany | volume = 59 | issue = 7 | pages = 1441–61 | date = 2008 | pmid = 17578868 | doi = 10.1093/jxb/erm112 | doi-access = free }}</ref> or by changing the leaf form or size.<ref name="pmid20460583">{{cite journal | vauthors = Gonzalez N, De Bodt S, Sulpice R, Jikumaru Y, Chae E, Dhondt S, Van Daele T, De Milde L, Weigel D, Kamiya Y, Stitt M, Beemster GT, Inzé D | display-authors = 6 | title = Increased leaf size: different means to an end | journal = Plant Physiology | volume = 153 | issue = 3 | pages = 1261–79 | date = July 2010 | pmid = 20460583 | pmc = 2899902 | doi = 10.1104/pp.110.156018  }}</ref><ref>{{cite journal | vauthors = Koenig D, Bayer E, Kang J, Kuhlemeier C, Sinha N | title = Auxin patterns Solanum lycopersicum leaf morphogenesis | journal = Development | volume = 136 | issue = 17 | pages = 2997–3006 | date = September 2009 | pmid = 19666826 | doi = 10.1242/dev.033811 | url = http://dev.biologists.org/content/136/17/2997.abstract | doi-access = free }}</ref><ref>{{Cite web|url=http://oai.cwi.nl/oai/asset/18965/18965D.pdf|title=Projects changing respectively plant growth and plant flowers}}{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{Cite web|url=http://oai.cwi.nl/oai/asset/18965/18965D.pdf|title=Project changing number of stomata in plants conducted by Ikuko Hara-Nishimura}}{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Plants have been engineered to exhibit [[Physics:Bioluminescence|bioluminescence]] that may become a sustainable alternative to electric lighting.<ref>{{cite web | date = 4 May 2013 | url = https://www.newscientist.com/article/mg21829156.500-one-per-cent.html | title = One Per Cent: Grow your own living lights | work = New Scientist | issue = 2915 }}</ref>

=== Cisgenic ===
[[Biology:Cisgenesis|Cisgenic]] plants are made using genes found within the same species or a closely related one, where conventional [[Biology:Plant breeding|plant breeding]] can occur. Some breeders and scientists argue that cisgenic modification is useful for plants that are difficult to [[Biology:Crossbreed|crossbreed]] by conventional means (such as potatoes), and that plants in the cisgenic category should not require the same regulatory scrutiny as transgenics.<ref>{{cite web | vauthors = MacKenzie D | date = 2 August 2008 | url = https://www.newscientist.com/article/mg19926671.600-how-the-humble-potato-could-feed-the-world.html | title = How the humble potato could feed the world | work = New Scientist | issue = 2667 | pages = 30–33 }}</ref>

=== Subgenic ===
Genetically modified plants can also be developed using [[Biology:Gene knockdown|gene knockdown]] or [[Biology:Gene knockout|gene knockout]] to alter the genetic makeup of a plant without incorporating genes from other plants. In 2014, Chinese researcher Gao Caixia filed patents on the creation of a strain of [[Biology:Wheat|wheat]] that is resistant to [[Biology:Powdery mildew|powdery mildew]]. The strain lacks genes that encode proteins that repress defenses against the mildew. The researchers deleted all three copies of the genes from wheat's hexaploid genome. Gao used the [[Biology:Transcription activator-like effector nuclease|TALENs]] and [[Biology:CRISPR|CRISPR]] [[Biology:Genome editing|gene editing]] tools without adding or changing any other genes. No field trials were immediately planned.<ref name=tr1407>{{cite web| vauthors = Talbot D |url= http://www.technologyreview.com/news/529181/chinese-researchers-stop-wheat-disease-with-gene-editing/ |title=Beijing Researchers Use Gene Editing to Create Disease-Resistant Wheat &#124; MIT Technology Review |publisher=Technologyreview.com |date=19 July 2014 |access-date=23 July 2014}}</ref><ref>{{cite journal | vauthors = Wang Y, Cheng X, Shan Q, Zhang Y, Liu J, Gao C, Qiu JL | s2cid = 205280231 | title = Simultaneous editing of three homoeoalleles in hexaploid bread wheat confers heritable resistance to powdery mildew | journal = Nature Biotechnology | volume = 32 | issue = 9 | pages = 947–51 | date = September 2014 | pmid = 25038773 | doi = 10.1038/nbt.2969 }}</ref> The CRISPR technique has also been used by Penn State researcher Yinong Yang to modify white button mushrooms (''[[Biology:Agaricus bisporus|Agaricus bisporus]]'') to be non-browning,<ref>{{cite journal | vauthors = Waltz E | title = Gene-edited CRISPR mushroom escapes US regulation | journal = Nature | volume = 532 | issue = 7599 | pages = 293 | date = April 2016 | pmid = 27111611 | doi = 10.1038/nature.2016.19754 | doi-access = free | bibcode = 2016Natur.532..293W }}</ref> and by DuPont Pioneer to make a new variety of corn.<ref>{{cite web | vauthors = Brodwin E | date = 18 April 2016 | url = https://www.businessinsider.com/dupont-crispr-corn-in-stores-in-5-years | title = The next generation of GMO food is here, and it's technically not a GMO | work = Business Insider }}</ref>

=== Multiple trait integration ===
With multiple trait integration, several new traits may be integrated into a new crop.<ref>{{cite journal | vauthors = Sun X, Mumm RH | title = Optimized breeding strategies for multiple trait integration: III. Parameters for success in version testing | journal = Molecular Breeding | volume = 35 | issue = 10 | pages = 201 | year = 2015 | pmid = 26491398 | pmc = 4605974 | doi = 10.1007/s11032-015-0397-z }}</ref>

==Economics==
{{POV section|date=December 2015}}
GM food's economic value to farmers is one of its major benefits, including in developing nations.<ref>{{cite web | url = http://www.agbioworld.org/biotech-info/articles/biotech-art/raney.html | title = Economic Impact of Transgenic Crops in Developing Countries | work = Agbioworld.org | access-date = 8 February 2011 }}</ref><ref>{{cite journal |doi=10.1017/S0021859612000111 |title=Economic and agronomic impact of commercialized GM crops: A meta-analysis |year=2012 | vauthors = Areal FJ, Riesgo L, Rodríguez-Cerezo E |journal=The Journal of Agricultural Science |volume=151 |pages=7–33|s2cid=85891950 }}</ref><ref name=Sustainability2011>{{cite journal | vauthors = Finger R, El Benni N, Kaphengst T, Evans C, Herbert S, Lehmann B, Morse S, Stupak N |doi=10.3390/su3050743 |title=A Meta Analysis on Farm-Level Costs and Benefits of GM Crops |year=2011 |journal=Sustainability |volume=3 |issue=12 |pages=743–62|url=https://www.research-collection.ethz.ch/bitstream/20.500.11850/42242/1/sustainability-03-00743.pdf |doi-access=free }}</ref> A 2010 study found that Bt corn provided economic benefits of $6.9 billion over the previous 14 years in five Midwestern states. The majority ($4.3 billion) accrued to farmers producing non-Bt corn. This was attributed to European corn borer populations reduced by exposure to Bt corn, leaving fewer to attack conventional corn nearby.<ref name="pmid20929774">{{cite journal | vauthors = Hutchison WD, Burkness EC, Mitchell PD, Moon RD, Leslie TW, Fleischer SJ, Abrahamson M, Hamilton KL, Steffey KL, Gray ME, Hellmich RL, Kaster LV, Hunt TE, Wright RJ, Pecinovsky K, Rabaey TL, Flood BR, Raun ES | s2cid = 238816 | display-authors = 6 | title = Areawide suppression of European corn borer with Bt maize reaps savings to non-Bt maize growers | journal = Science | volume = 330 | issue = 6001 | pages = 222–5 | date = October 2010 | pmid = 20929774 | doi = 10.1126/science.1190242 | url = http://lib.dr.iastate.edu/ent_pubs/122 | bibcode = 2010Sci...330..222H }}</ref><ref>{{cite web | vauthors = Karnowski S | url = http://www.sci-tech-today.com/news/New-Language-Found-Hidden-in-India/story.xhtml?story_id=02100000XZPX | title = High-Tech Corn Fights Pests at Home and Nearby | work = Sci-Tech Today | date= 8 October 2010 | access-date = 9 October 2010 }}{{dead link|date=October 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Agriculture economists calculated that "world surplus [increased by] $240.3 million for 1996. Of this total, the largest share (59%) went to U.S. farmers. Seed company Monsanto received the next largest share (21%), followed by US consumers (9%), the rest of the world (6%), and the germplasm supplier, Delta & Pine Land Company of Mississippi (5%)."<ref>{{cite journal |doi=10.1111/0002-9092.00031 |jstor=1244657 |title=Surplus Distribution from the Introduction of a Biotechnology Innovation |year=2000 | vauthors = Falck-Zepeda JB, Traxler G, Nelson RG |s2cid=153595694 |journal=American Journal of Agricultural Economics |volume=82 |issue=2 |pages=360–69}}</ref>

According to the International Service for the Acquisition of Agri-biotech Applications (ISAAA), in 2014 approximately 18 million farmers grew biotech crops in 28 countries; about 94% of the farmers were resource-poor in developing countries. 53% of the global biotech crop area of 181.5 million hectares was grown in 20 developing countries.<ref name=James2014/> PG Economics comprehensive 2012 study concluded that GM crops increased farm incomes worldwide by $14 billion in 2010, with over half this total going to farmers in developing countries.<ref name = PGEconomics>{{cite book | vauthors = Brookes G, Barfoot P | title = GM crops: global socio-economic and environmental impacts 1996-2010 | publisher = PG Economics Ltd. | url = http://www.pgeconomics.co.uk/pdf/2012globalimpactstudyfinal.pdf }}</ref>

Forgoing these benefits is costly.<ref name="Eenennaam-et-al-2021">{{cite journal | last1=Van Eenennaam | first1=Alison L. | last2=De Figueiredo Silva | first2=Felipe | last3=Trott | first3=Josephine F. | last4=Zilberman | first4=David | title=Genetic Engineering of Livestock: The Opportunity Cost of Regulatory Delay | journal=Annual Review of Animal Biosciences | publisher=Annual Reviews | volume=9 | issue=1 | date=16 February 2021 | issn=2165-8102 | doi=10.1146/annurev-animal-061220-023052 | pages=453–478| pmid=33186503 | s2cid=226948372 | doi-access=free }}</ref><ref name="Zilberman-et-al-2015">{{cite journal | title=The Loss from Underutilizing GM Technologies | journal=AgBioForum | publisher=Illinois Missouri Biotechnology Alliance | date=17 February 2022 | url=http://agbioforum.org/the-loss-from-underutilizing-gm-technologies/ | s2cid=56129052 | first1=David | last1=Zilberman | first2=Scott | last2=Kaplan | first3=Justus | last3=Wesseler}}</ref> Wesseler ''et al.'', 2017 estimate the cost of delay for several crops including GM banana in Uganda, GM cowpea in [[Place:West Africa|west Africa]], and GM maize/corn in Kenya.<ref name="Eenennaam-et-al-2021" /> They estimate Nigeria alone loses $33–46m annually.<ref name="Eenennaam-et-al-2021" /> The potential and alleged harms of GM crops must then be compared to these costs of delay.<ref name="Eenennaam-et-al-2021" /><ref name="Zilberman-et-al-2015" />

Critics challenged the claimed benefits to farmers over the prevalence of biased observers and by the absence of [[Randomized controlled trial|randomized controlled trial]]s.{{citation needed|date=February 2015}} The main Bt crop grown by small farmers in developing countries is cotton. A 2006 review of Bt cotton findings by agricultural economists concluded, "the overall balance sheet, though promising, is mixed. Economic returns are highly variable over years, farm type, and geographical location".<ref name=Smale_2006>{{cite journal |vauthors=Smale M, Zambrano P, Cartel M |url=http://www.agbioforum.org/v9n3/v9n3a06-zambrano.pdf |title=Bales and balance: A review of the methods used to assess the economic impact of Bt cotton on farmers in developing economies |journal=AgBioForum |volume=9 |issue=3 |pages=195–212 |year=2006 |access-date=8 February 2016 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304122530/http://www.agbioforum.org/v9n3/v9n3a06-zambrano.pdf |url-status=dead }}</ref>

In 2013 the European Academies Science Advisory Council (EASAC) asked the EU to allow the development of agricultural GM technologies to enable more sustainable agriculture, by employing fewer land, water, and nutrient resources. EASAC also criticizes the EU's "time-consuming and expensive regulatory framework" and said that the EU had fallen behind in the adoption of GM technologies.<ref name=easac>{{cite journal | author = European Academies Science Advisory Council (EASAC) | title =  Planting the future: opportunities and challenges for using crop genetic improvement technologies for sustainable agriculture. | journal = EASAC Policy Report | date = 27 June 2013 | page = 21 | url = http://www.easac.eu/home/reports-and-statements/detail-view/article/planting-the.html }}</ref>

Participants in agriculture business markets include seed companies, agrochemical companies, distributors, farmers, grain elevators and universities that develop new crops/traits and whose agricultural extensions advise farmers on best practices.{{citation needed|date=July 2015}} According to a 2012 review based on data from the late 1990s and early 2000s, much of the GM crop grown each year is used for livestock feed and increased demand for meat leads to increased demand for GM feed crops.<ref name="Rajib">{{cite journal | vauthors = Tilling T, Neeta L, Vikuolie M, Rajib D | title = Genetically modified (GM) crops lifeline for livestock-a review. | journal = Agricultural Reviews | date = 2010 | volume = 31 | issue = 4 | pages = 279–85 | url = http://www.cabdirect.org/abstracts/20133080162.html }}</ref> Feed grain usage as a percentage of total crop production is 70% for corn and more than 90% of oil seed meals such as soybeans. About 65 million metric tons of GM corn grains and about 70 million metric tons of soybean meals derived from GM soybean become feed.<ref name="Rajib" />

In 2014 the global value of biotech seed was US$15.7 billion; US$11.3 billion (72%) was in industrial countries and US$4.4 billion (28%) was in the developing countries.<ref name=James2014>{{cite journal | vauthors = James C | date = 2014 | url = http://isaaa.org/resources/publications/pocketk/16/default.asp | title = Global Status of Commercialized Biotech/GM Crops: 2014 | journal = ISAAA Brief | issue = 49 }}</ref> In 2009, Monsanto had $7.3 billion in sales of seeds and from licensing its technology; DuPont, through its Pioneer subsidiary, was the next biggest company in that market.<ref name=ForbesPlanet>{{cite web | vauthors = Langreth R, Herper M | work = Forbes | date = 31 December 2009 | url = https://www.forbes.com/forbes/2010/0118/americas-best-company-10-gmos-dupont-planet-versus-monsanto.html | title = The Planet Versus Monsanto }}</ref> As of 2009, the overall Roundup line of products including the GM seeds represented about 50% of Monsanto's business.<ref>{{cite news|url=https://www.forbes.com/2009/06/29/monsanto-potash-fertilizer-personal-finance-investing-ideas-agrium-mosaic.html|title=The Seeds Of A Monsanto Short Play| vauthors = Cavallaro M |date=26 June 2009|work=Forbes}}</ref>

Some patents on GM traits have expired, allowing the legal development of generic strains that include these traits. For example, generic glyphosate-tolerant GM soybean is now available. Another impact is that traits developed by one vendor can be added to another vendor's proprietary strains, potentially increasing product choice and competition.<ref>{{cite web|title = Monsanto Roundup Ready Soybean Patent Expiration Ushers in Generic GMOs {{!}} MIT Technology Review|url = http://www.technologyreview.com/news/539746/as-patents-expire-farmers-plant-generic-gmos/|website = MIT Technology Review|access-date = 22 October 2015|date = 30 July 2015| vauthors = Regalado A }}</ref> The patent on the first type of ''Roundup Ready'' crop that Monsanto produced (soybeans) expired in 2014<ref>{{cite news|url=http://www.businessweek.com/magazine/content/10_05/b4165019364939.htm|archive-url=https://web.archive.org/web/20100127202826/http://www.businessweek.com/magazine/content/10_05/b4165019364939.htm|url-status=dead|archive-date=27 January 2010|title=Monsanto Will Let Bio-Crop Patents Expire|date=21 January 2010|work=BusinessWeek}}</ref> and the first harvest of off-patent soybeans occurs in the spring of 2015.<ref>{{cite web | publisher = Monsanto | url = http://www.monsanto.com/newsviews/pages/roundup-ready-patent-expiration.aspx | title = Roundup Ready Soybean Patent Expiration }}</ref> Monsanto has broadly licensed the patent to other seed companies that include the glyphosate resistance trait in their seed products.<ref>{{cite web|url=http://www.monsanto.com/whoweare/Pages/seed-licensing.aspx |title=Monsanto ~ Licensing |publisher=Monsanto.com |date=3 November 2008 }}</ref> About 150 companies have licensed the technology,<ref>{{cite news | url = https://www.npr.org/templates/story/story.php?storyId=122498255 | title = Monsanto GMO Ignites Big Seed War | work = NPR }}</ref> including Syngenta<ref>{{cite web|url=http://www.syngenta.com/country/us/en/Seeds/Traits/SoybeanTraits/Pages/content_authoring_RR_detail_page.aspx |title=Syngenta US &#124; Corn and Soybean Seed – Garst, Golden Harvest, NK, Agrisure |publisher=Syngenta.com}}</ref> and DuPont Pioneer.<ref>{{cite web |url=https://www.pioneer.com/home/site/us/agronomy/library/template.CONTENT/guid.80D8C28A-31F7-C434-64D9-D61AAF9D661C/ |title=Agronomy Library – Pioneer Hi-Bred Agronomy Library |publisher=Pioneer.com |access-date=1 March 2015 |archive-date=17 October 2012 |archive-url=https://web.archive.org/web/20121017162512/https://www.pioneer.com/home/site/us/agronomy/library/template.CONTENT/guid.80D8C28A-31F7-C434-64D9-D61AAF9D661C/ |url-status=dead }}</ref>

== Yield ==
In 2014, the largest review yet concluded that GM crops' effects on farming were positive. The [[Meta-analysis|meta-analysis]] considered all published English-language examinations of the agronomic and economic impacts between 1995 and March 2014 for three major GM crops: soybean, maize, and cotton. The study found that herbicide-tolerant crops have lower production costs, while for insect-resistant crops the reduced pesticide use was offset by higher seed prices, leaving overall production costs about the same.<ref name="KlumperQaim">{{cite journal | vauthors = Klümper W, Qaim M | title = A meta-analysis of the impacts of genetically modified crops | journal = PLOS ONE | volume = 9 | issue = 11 | pages = e111629 | year = 2014 | pmid = 25365303 | pmc = 4218791 | doi = 10.1371/journal.pone.0111629 | bibcode = 2014PLoSO...9k1629K | doi-access = free }} {{open access}}</ref><ref name="auto">{{cite news|url = https://www.economist.com/news/science-and-technology/21630961-biggest-study-so-far-finds-gm-crops-have-large-widespread-benefits-field|title = Genetically modified crops - Field research|date= 8 November 2014|work = Economist|access-date =3 October 2016}}</ref>

Yields increased 9% for herbicide tolerance and 25% for insect resistant varieties. Farmers who adopted GM crops made 69% higher profits than those who did not. The review found that GM crops help farmers in developing countries, increasing yields by 14 percentage points.<ref name="auto"/>

The researchers considered some studies that were not peer-reviewed and a few that did not report sample sizes. They attempted to correct for [[Publication bias|publication bias]], by considering sources beyond academic journals. The large data set allowed the study to control for potentially confounding variables such as fertilizer use. Separately, they concluded that the funding source did not influence study results.<ref name="auto" />

Under special conditions meant to reveal only genetic yield factors, many GM crops are known to actually have ''lower'' yields. This is variously due to one or both of: Yield drag, wherein the trait itself lowers yield, either by competing for synthesis [[Chemistry:Substrate|feedstock]] or by being inserted slightly inaccurately, into the middle of a yield-relevant gene; and/or yield lag, wherein it takes some time to breed the newest yield genetics into the GM lines. This does not reflect realistic field conditions however, especially leaving out pest pressure which is often the point of the GM trait.<ref name="UCS">{{cite book | url=http://www.ucsusa.org/sites/default/files/2019-10/failure-to-yield.pdf | title=Failure To Yield - Evaluating the Performance of Genetically Engineered Crops | last=Gurian-Sherman | first=Douglas | s2cid=6332194 | publisher=[[Organization:Union of Concerned Scientists|Union of Concerned Scientists]] | date=April 2009}}</ref> See for example [[Biology:Roundup Ready#Productivity claims|Roundup Ready § Productivity claims]].

Gene editing may also increase yields non-specific to the use of any biocides/pesticides. In March 2022, field test results showed [[Biology:CRISPR gene editing|CRISPR]]-based [[Biology:Gene knockout|gene knockout]] of KRN2 in maize and OsKRN2 in rice increased grain yields by ~10% and ~8% without any detected negative effects.<ref>{{cite news |title=Rice and maize yields boosted up to 10 per cent by CRISPR gene editing |url=https://www.newscientist.com/article/2313582-rice-and-maize-yields-boosted-up-to-10-per-cent-by-crispr-gene-editing/ |access-date=19 April 2022 |work=New Scientist}}</ref><ref>{{cite journal |last1=Chen |first1=Wenkang |last2=Chen |first2=Lu |last3=Zhang |first3=Xuan |last4=Yang |first4=Ning |last5=Guo |first5=Jianghua |last6=Wang |first6=Min |last7=Ji |first7=Shenghui |last8=Zhao |first8=Xiangyu |last9=Yin |first9=Pengfei |last10=Cai |first10=Lichun |last11=Xu |first11=Jing |last12=Zhang |first12=Lili |last13=Han |first13=Yingjia |last14=Xiao |first14=Yingni |last15=Xu |first15=Gen |last16=Wang |first16=Yuebin |last17=Wang |first17=Shuhui |last18=Wu |first18=Sheng |last19=Yang |first19=Fang |last20=Jackson |first20=David |last21=Cheng |first21=Jinkui |last22=Chen |first22=Saihua |last23=Sun |first23=Chuanqing |last24=Qin |first24=Feng |last25=Tian |first25=Feng |last26=Fernie |first26=Alisdair R. |last27=Li |first27=Jiansheng |last28=Yan |first28=Jianbing |last29=Yang |first29=Xiaohong |title=Convergent selection of a WD40 protein that enhances grain yield in maize and rice |journal=Science |date=25 March 2022 |volume=375 |issue=6587 |pages= eabg7985|doi=10.1126/science.abg7985 | pmid=35324310  |s2cid=247677363 |url=https://www.science.org/doi/10.1126/science.abg7985|url-access=subscription}}</ref>

==Traits==
[[File:Älskade knöl – utflykt med SLU till deras potatisförsöksodlingar – 20190825 09 (cropped).jpg|thumb|Genetically modified King Edward potato (right) next to King Edward which has not been genetically modified (left). Research field belonging to the Swedish University of Agricultural Sciences in 2019.]]
GM crops grown today, or under development, have been modified with various [[Biology:Phenotypic trait|traits]]. These traits include improved [[Finance:Shelf life|shelf life]], [[Biology:Plant disease resistance|disease resistance]], stress resistance, herbicide resistance, pest resistance, production of useful goods such as biofuel or drugs, and ability to absorb toxins and for use in [[Earth:Bioremediation|bioremediation]] of pollution.

Recently, [[Research and development|research and development]] has been targeted to enhancement of crops that are locally important in developing countries, such as insect-resistant [[Biology:Cowpea|cowpea]] for Africa<ref>{{Cite web|url=https://www.seedquest.com/News/releases/2006/august/16608.htm|title=SeedQuest - Central information website for the global seed industry|website=www.seedquest.com}}</ref> and insect-resistant [[Biology:Bt brinjal|brinjal]] (eggplant).<ref>{{cite web|url=http://www.isaaa.org/resources/publications/pocketk/35/default.asp|title=Bt Brinjal in India - Pocket K - ISAAA.org|website=www.isaaa.org}}</ref>

===Extended shelf life===
The first genetically modified crop approved for sale in the U.S. was the ''FlavrSavr'' tomato, which had a longer shelf life.<ref name="doi10.3733/ca.v054n04p6">{{cite journal | vauthors = Bruening G, Lyons JM | year = 2000  | title = The case of the FLAVR SAVR tomato | journal = California Agriculture | volume = 54 | issue = 4 | pages = 6–7 | url = http://ucanr.org/repository/CAO/landingpage.cfm?article=ca.v054n04p6&fulltext=yes | doi=10.3733/ca.v054n04p6| doi-access = free }}</ref> First sold in 1994, FlavrSavr tomato production ceased in 1997.<ref name="fray">{{cite book | vauthors = Weasel LH | title = Food Fray | location = New York | publisher = Amacom Publishing | date = December 2008 | isbn = 978-0-8144-3640-0 }}</ref> It is no longer on the market.

In November 2014, the USDA approved a GM potato that prevents bruising.<ref name="NYTsimplot">{{cite web | vauthors = Pollack A | work = The New York Times | date = 7 November 2014 | url = https://www.nytimes.com/2014/11/08/business/genetically-modified-potato-from-simplot-approved-by-usda.html | title = U.S.D.A. Approves Modified Potato. Next Up: French Fry Fans }}</ref><ref name="FR_2013">{{cite web | work = Federal Register | date = 3 May 2013 | url = https://www.federalregister.gov/articles/2013/05/03/2013-10504/jr-simplot-co-availability-of-petition-for-determination-of-nonregulated-status-of-potato#h-7 | title = J.R. Simplot Co.; Availability of Petition for Determination of Nonregulated Status of Potato Genetically Engineered for Low Acrylamide Potential and Reduced Black Spot Bruise }}</ref>

In February 2015 [[Biology:Arctic Apples|Arctic Apples]] were approved by the USDA,<ref name="AAapprov">{{cite web | vauthors = Pollack A | url = https://www.nytimes.com/2015/02/14/business/gmo-apples-are-approved-for-growing-in-us.html | title = Gene-Altered Apples Get U.S. Approval | work = The New York Times | date = 13 February 2015 }}</ref> becoming the first genetically modified apple approved for US sale.<ref name="Tennille_2015">{{cite web |url=https://www.wsj.com/articles/first-genetically-modified-apple-approved-for-sale-in-u-s-1423863994 |title=First Genetically Modified Apple Approved for Sale in U.S. | vauthors = Tennille T |date=13 February 2015 |website=Wall Street Journal|access-date=3 October 2016}}</ref> [[Biology:Gene silencing|Gene silencing]] was used to reduce the expression of [[Biology:Polyphenol oxidase|polyphenol oxidase (PPO)]], thus preventing enzymatic browning of the fruit after it has been sliced open. The trait was added to [[Biology:Granny Smith|Granny Smith]] and [[Biology:Golden Delicious|Golden Delicious]] varieties.<ref name="AAapprov"/><ref name="AAmech">{{cite web | url = http://www.arcticapples.com/arctic-apples-story/how-we-keep-apples-from-turning-brown | title = Apple-to-apple transformation | archive-url = https://web.archive.org/web/20130925060233/http://www.arcticapples.com/arctic-apples-story/how-we-keep-apples-from-turning-brown | archive-date=25 September 2013 | work = Okanagan Specialty Fruits | access-date = 3 August 2012 }}</ref> The trait includes a bacterial antibiotic resistance gene that provides resistance to the antibiotic kanamycin. The genetic engineering involved cultivation in the presence of kanamycin, which allowed only resistant cultivars to survive. Humans consuming apples do not acquire kanamycin resistance, per arcticapple.com.<ref>{{cite web|url = http://www.arcticapples.com/faq#t20n122|title = Arctic apples FAQ|date = 2014|access-date =3 October 2016|publisher = Arctic Apples}}</ref> The FDA approved the apples in March 2015.<ref>{{cite web|url = https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm439121.htm|title = FDA concludes Arctic Apples and Innate Potatoes are safe for consumption|date = 20 March 2015|publisher = United States [[Organization:Food and Drug Administration|Food and Drug Administration]]}}</ref>

=== Improved photosynthesis ===
Plants use [[Biology:Non-photochemical quenching|non-photochemical quenching]] to protect them from excessive amounts of sunlight. Plants can switch on the quenching mechanism almost instantaneously, but it takes much longer for it to switch off again. During the time that it is switched off, the amount of energy that is wasted increases.<ref name="Krom">{{cite journal | vauthors = Kromdijk J, Głowacka K, Leonelli L, Gabilly ST, Iwai M, Niyogi KK, Long SP | title = Improving photosynthesis and crop productivity by accelerating recovery from photoprotection | journal = Science | volume = 354 | issue = 6314 | pages = 857–861 | date = November 2016 | pmid = 27856901 | doi = 10.1126/science.aai8878 | doi-access = free | bibcode = 2016Sci...354..857K }}</ref> A genetic modification in three genes allows to correct this (in a trial with tobacco plants). As a result, yields were 14-20% higher, in terms of the weight of the dry leaves harvested. The plants had larger leaves, were taller and had more vigorous roots.<ref name=Krom/><ref>{{cite news|url=https://www.theguardian.com/science/2016/nov/17/plants-genetically-modified-to-boost-photosynthesis-produce-greater-yields-study-shows|title=Plants modified to boost photosynthesis produce greater yields, study shows|work=The Guardian| vauthors = Devlin H |date=17 November 2016|access-date=27 July 2019}}</ref>

Another improvement that can be made on the photosynthesis process (with [[Biology:C3 carbon fixation|C3 pathway plants]]) is on [[Biology:Photorespiration|photorespiration]]. By inserting the C4 pathway into C3 plants, productivity may increase by as much as 50% for cereal crops, such as rice.<ref>{{cite web | vauthors = Thompson S | date = 24 January 2017 | url = https://theconversation.com/how-gm-crops-can-help-us-to-feed-a-fast-growing-world-71112 | title = How GM crops can help us to feed a fast-growing world | work = The Conversation }}</ref><ref>{{cite web | url = https://www.technologyreview.com/s/535011/supercharged-photosynthesis/ | title = Advanced genetic tools could help boost crop yields and feed billions more people. | access-date = 10 August 2018 | archive-date = 9 September 2018 | archive-url = https://web.archive.org/web/20180909102855/https://www.technologyreview.com/s/535011/supercharged-photosynthesis/ | url-status = dead }}</ref><ref>{{cite web | vauthors = Best S | date = 24 October 2017 | url = https://geneticliteracyproject.org/2017/10/24/supercharged-gmo-rice-variety-increase-yields-50-percent-improved-photosynthesis/ | title = 'Supercharged' GMO rice could increase yields 50 percent with improved photosynthesis }}</ref><ref>{{cite journal | vauthors = Karki S, Rizal G, Quick WP | title = Improvement of photosynthesis in rice (Oryza sativa L.) by inserting the C4 pathway | journal = Rice | volume = 6 | issue = 1 | pages = 28 | date = October 2013 | pmid = 24280149 | pmc = 4883725 | doi = 10.1186/1939-8433-6-28 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Evans JR | title = Improving photosynthesis | journal = Plant Physiology | volume = 162 | issue = 4 | pages = 1780–93 | date = August 2013 | pmid = 23812345 | pmc = 3729760 | doi = 10.1104/pp.113.219006 }}</ref>

===Improved biosequestration capability===
The Harnessing Plants Initiative focuses on creating GM plants that have increased root mass, root depth and suberin content.

===Improved nutritional value===

==== Edible oils ====
Some GM soybeans offer improved oil profiles for processing.<ref>{{cite web | vauthors = Pollack A | work = The New York Times | date = 15 November 2013 | url = https://www.nytimes.com/2013/11/16/business/in-a-bean-a-boon-to-biotech.html | title = In a Bean, a Boon to Biotech }}</ref> ''[[Biology:Camelina sativa|Camelina sativa]]'' has been modified to produce plants that accumulate high levels of oils similar to fish oils.<ref>{{cite web | url = http://www.rothamsted.ac.uk/news/crop-plants-green-factories-fish-oils | title = Crop plants – "green factories" for fish oils | work = Rothamsted Research | date = 14 November 2013 }}</ref><ref>{{cite journal | vauthors = Ruiz-Lopez N, Haslam RP, Napier JA, Sayanova O | title = Successful high-level accumulation of fish oil omega-3 long-chain polyunsaturated fatty acids in a transgenic oilseed crop | journal = The Plant Journal | volume = 77 | issue = 2 | pages = 198–208 | date = January 2014 | pmid = 24308505 | pmc = 4253037 | doi = 10.1111/tpj.12378 }}</ref>

==== Vitamin enrichment ====
Golden rice, developed by the [[Organization:International Rice Research Institute|International Rice Research Institute]] (IRRI), provides greater amounts of [[Chemistry:Vitamin A|vitamin A]] targeted at reducing [[Medicine:Vitamin A deficiency|vitamin A deficiency]].<ref>{{cite web | url = http://www.irri.org/index.php?option=com_k2&view=item&layout=item&id=10202&Itemid=100571&lang=en | title = About Golden Rice | archive-url = https://web.archive.org/web/20121102112216/http://www.irri.org/index.php?option=com_k2&view=item&layout=item&id=10202&Itemid=100571&lang=en | archive-date=2 November 2012 | work = International Rice Research Institute | access-date = 20 August 2012 }}</ref><ref name="doi10.1038/news.2011.233">{{cite journal | vauthors = Nayar A | doi = 10.1038/news.2011.233 | title = Grants aim to fight malnutrition | journal = Nature | year = 2011 | doi-access = free }}</ref> As of January 2016, golden rice has not yet been grown commercially in any country.<ref>{{cite web| vauthors = Philpott T |title=WTF Happened to Golden Rice?|url=https://www.motherjones.com/tom-philpott/2016/02/golden-rice-still-showing-promise-still-not-field-ready|website=Mother Jones|access-date=24 March 2016|date=3 February 2016}}</ref>

==== Toxin reduction ====
A genetically modified [[Biology:Cassava|cassava]] under development offers lower [[Chemistry:Cyanogen|cyanogen]] glucosides and enhanced protein and other nutrients (called BioCassava).<ref>{{cite journal | vauthors = Sayre R, Beeching JR, Cahoon EB, Egesi C, Fauquet C, Fellman J, Fregene M, Gruissem W, Mallowa S, Manary M, Maziya-Dixon B, Mbanaso A, Schachtman DP, Siritunga D, Taylor N, Vanderschuren H, Zhang P | display-authors = 6 | title = The BioCassava plus program: biofortification of cassava for sub-Saharan Africa | journal = Annual Review of Plant Biology | volume = 62 | pages = 251–72 | year = 2011 | pmid = 21526968 | doi = 10.1146/annurev-arplant-042110-103751 }}</ref>

In November 2014, the USDA approved a potato that prevents bruising and produces less [[Chemistry:Acrylamide|acrylamide]] when fried.<ref name="NYTsimplot"/><ref name="FR_2013"/> They do not employ genes from non-potato species. The trait was added to the Russet Burbank, Ranger Russet and Atlantic varieties.<ref name="NYTsimplot"/>

===Stress resistance===
Plants have been engineered to tolerate non-biological stressors, such as [[Earth:Drought|drought]],<ref name="NYTsimplot" /><ref name="FR_2013" /><ref>{{cite report | vauthors = Paarlburg RD | title = Maize in Africa, Anticipating Regulatory Hurdles | work = International Life Sciences Institute | date = January 2011 | url = http://www.ilsi.org/Documents/2011%20AM%20Presentations/CERAPaarlberg.pdf | archive-url = https://web.archive.org/web/20141222081325/http://www.ilsi.org/Documents/2011%20AM%20Presentations/CERAPaarlberg.pdf | archive-date=22 December 2014 }}</ref><ref>{{cite web | url = http://www.gmo-compass.org/eng/news/371.docu.html | title = Australia continues to test drought-resistant GM wheat | archive-url = https://web.archive.org/web/20120316221209/http://www.gmo-compass.org/eng/news/371.docu.html | archive-date = 16 March 2012 | work = GMO Compass | date = 16 July 2008 | access-date = 25 April 2011 }}</ref> [[Earth:Frost|frost]],<ref>{{cite web | author = Staff | date = 14 May 2011 | url = http://www.gmo-compass.org/eng/news/512.usa_usda_allows_large_scale_gm_eucalyptus_trial.html | title = USA: USDA allows large-scale GM eucalyptus trial | archive-url = https://web.archive.org/web/20121026195223/http://www.gmo-compass.org/eng/news/512.usa_usda_allows_large_scale_gm_eucalyptus_trial.html | archive-date=26 October 2012 | work = GMO Compass | access-date = 29 September 2011 }}</ref> and high [[Physics:Soil salinity|soil salinity]].<ref name="banjara" /> In 2011, Monsanto's DroughtGard maize became the first drought-resistant GM crop to receive US marketing approval.<ref name="pmid24067764">{{cite journal | vauthors = Eisenstein M | s2cid = 4464117 | title = Plant breeding: Discovery in a dry spell | journal = Nature | volume = 501 | issue = 7468 | pages = S7–9 | date = September 2013 | pmid = 24067764 | doi = 10.1038/501S7a | bibcode = 2013Natur.501S...7E | doi-access = free }}</ref>

Drought resistance occurs by modifying the plant's genes responsible for the mechanism known as the [[Biology:Crassulacean acid metabolism|crassulacean acid metabolism]] (CAM), which allows the plants to survive despite low water levels. This holds promise for water-heavy crops such as rice, wheat, soybeans and poplar to accelerate their adaptation to water-limited environments.<ref>{{cite web | vauthors = Gabbatiss J | date = 4 December 2017 | url = https://www.independent.co.uk/news/science/drought-resistant-crops-plants-genetic-engineering-a8091816.html | title = Scientists aim to develop drought-resistant crops using genetic engineering | work = Independent }}</ref><ref>{{cite book | vauthors = Liang C | chapter = Genetically modified crops with drought tolerance: achievements, challenges, and perspectives. | title = Drought Stress Tolerance in Plants | volume = 2 | date = 2016 | pages = 531–547 | publisher = Springer | location = Cham. | chapter-url = https://www.researchgate.net/publication/307873609 }}</ref> Several salinity tolerance mechanisms have been identified in salt-tolerant crops. For example, rice, canola and tomato crops have been genetically modified to increase their tolerance to salt stress.<ref>{{cite web | url = http://www.isaaa.org/resources/publications/pocketk/31/default.asp | issue = Pocket K No. 31 | title = Biotechnology with Salinity for Coping in Problem Soils | publisher =  International Service for the Acquisition of Agri-biotech Applications (ISAAA)  }}</ref><ref>{{cite web | vauthors = Sawahel W | date = 22 July 2009 | url = https://www.scidev.net/global/biotechnology/news/genetic-change-could-make-crops-thrive-on-salty-so.html | title = Genetic change could make crops thrive on salty soils | work = SciDev.Net }}</ref>

=== Herbicides ===

==== Glyphosate ====
The most prevalent GM trait is herbicide tolerance,<ref>{{Cite web |last=ISAAA |title=ISAAA Brief 55-2019: Executive Summary |url=https://www.isaaa.org/resources/publications/briefs/55/executivesummary/default.asp |access-date=2023-09-29 |website=www.isaaa.org}}</ref> where [[Chemistry:Glyphosate|glyphosate]]-tolerance is the most common.<ref>{{Cite journal |last=Green |first=Jerry M |date=2014-01-20 |title=Current state of herbicides in herbicide‐resistant crops |url=https://onlinelibrary.wiley.com/doi/10.1002/ps.3727 |journal=Pest Management Science |language=en |volume=70 |issue=9 |pages=1351–1357 |doi=10.1002/ps.3727 |pmid=24446395 |issn=1526-498X}}</ref> Glyphosate (the active ingredient in Roundup and other herbicide products) kills plants by interfering with the [[Chemistry:Shikimic acid|shikimate]] pathway in plants, which is essential for the synthesis of the aromatic amino acids [[Chemistry:Phenylalanine|phenylalanine]], [[Chemistry:Tyrosine|tyrosine]], and [[Chemistry:Tryptophan|tryptophan]]. The shikimate pathway is not present in animals, which instead obtain aromatic amino acids from their diet. More specifically, glyphosate inhibits the enzyme [[Biology:EPSP synthase|5-enolpyruvylshikimate-3-phosphate synthase]] (EPSPS).

This trait was developed because the herbicides used on grain and grass crops at the time were highly toxic and not effective against narrow-leaved weeds. Thus, developing crops that could withstand spraying with glyphosate would both reduce environmental and health risks, and give an agricultural edge to the farmer.<ref name="agbioforum1999">{{cite journal | vauthors = Carpenter J, Gianessi L | year = 1999 | title = Herbicide tolerant soybeans: Why growers are adopting Roundup Ready varieties | url = http://agbioforum.org/v2n2/v2n2a02-carpenter.htm | journal = AgBioForum | volume = 2 | issue = 2 | pages = 65–72 | access-date = 7 December 2013 | archive-date = 19 November 2012 | archive-url = https://web.archive.org/web/20121119133446/http://www.agbioforum.org/v2n2/v2n2a02-carpenter.htm | url-status = dead }}</ref>

Some micro-organisms have a version of EPSPS that is resistant to glyphosate inhibition. One of these was isolated from an ''[[Biology:Agrobacterium|Agrobacterium]]'' strain CP4 (CP4 EPSPS) that was resistant to glyphosate.<ref>{{cite journal | vauthors = Heck GR, Armstrong CL, Astwood JD, Behr CF, Bookout JT, Brown SM, Cavato TA, DeBoer DL, Deng MY, George C, Hillyard JR | display-authors = 6 | title = Development and Characterization of a CP4 EPSPS-Based, Glyphosate-Tolerant Corn Event | journal = Crop Sci. | volume = 45 | pages = 329–39 | date = 1 January 2005 | doi = 10.2135/cropsci2005.0329 | url = http://crop.scijournals.org/cgi/content/full/45/1/329 | format = Free full text | issue = 1 | url-status = dead | archive-url = https://web.archive.org/web/20090822080820/http://crop.scijournals.org/cgi/content/full/45/1/329 | archive-date = 22 August 2009 | df = dmy-all }}</ref><ref>{{cite journal | vauthors = Funke T, Han H, Healy-Fried ML, Fischer M, Schönbrunn E | title = Molecular basis for the herbicide resistance of Roundup Ready crops | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 103 | issue = 35 | pages = 13010–5 | date = August 2006 | pmid = 16916934 | pmc = 1559744 | doi = 10.1073/pnas.0603638103 | bibcode = 2006PNAS..10313010F | doi-access = free }}</ref> The CP4 EPSPS gene was engineered for plant [[Biology:Gene expression|expression]] by fusing the 5' end of the gene to a [[Biology:Chloroplast|chloroplast]] transit peptide derived from the [[Biology:Petunia|petunia]] EPSPS. This transit peptide was used because it had shown previously an ability to deliver bacterial EPSPS to the chloroplasts of other plants. This CP4 EPSPS gene was [[Biology:Cloning#Molecular cloning|cloned]] and [[Biology:Transfection|transfected]] into soybeans.

The [[Biology:Plasmid|plasmid]] used to move the gene into soybeans was PV-GMGTO4. It contained three bacterial genes, two CP4 EPSPS genes, and a gene encoding [[Biology:Beta-glucuronidase|beta-glucuronidase]] (GUS) from ''[[Biology:Escherichia coli|Escherichia coli]]'' as a marker. The DNA was injected into the soybeans using the [[Biology:Gene gun|particle acceleration method]]. Soybean cultivar A54O3 was used for the [[Biology:Transformation (genetics)|transformation]].

==== Bromoxynil ====
Tobacco plants have been engineered to be resistant to the herbicide [[Chemistry:Bromoxynil|bromoxynil]].<ref name="Debora MacKenzie">{{cite journal|title=Transgenic tobacco is European first|date=18 June 1994| vauthors = MacKenzie D |url=https://www.newscientist.com/article/mg14219301.100-transgenic-tobacco-is-european-first.html|journal=New Scientist}}</ref>

==== Glufosinate ====
Crops have been commercialized that are resistant to the herbicide [[Chemistry:Glufosinate|glufosinate]], as well.<ref>{{cite book | vauthors = Gianessi LP, Silvers CS, Sankula S, Carpenter JE | title = Plant biotechnology: current and potential impact for improving pest management in US agriculture: an analysis of 40 case studies.| publisher = National Center for Food and Agricultural Policy | location = Washington, DC | date = June 2002 | url = http://www.massey.ac.nz/~ychisti/Plantbio.pdf | archive-url = https://web.archive.org/web/20160303233648/http://www.massey.ac.nz/~ychisti/Plantbio.pdf | archive-date=3 March 2016 }}</ref> Crops engineered for resistance to multiple herbicides to allow farmers to use a mixed group of two, three, or four different chemicals are under development to combat growing herbicide resistance.<ref>{{cite web | vauthors = Kasey J | date = 8 September 2011 | url = http://mobile.businessweek.com/article/magazine/attack-of-the-superweed-09082011.html?section=highlights | title = Attack of the Superweed | work = Bloomberg Businessweek }}{{dead link|date=April 2023|bot=medic}}{{cbignore|bot=medic}} </ref><ref>{{cite web | vauthors = Ganchiff M | work = Midwest Wine Press | date = 24 August 2013 | url = http://midwestwinepress.com/2013/08/24/new-herbicide-resistant-row-crops-seeking-approval/ | title = New Herbicide Resistant Crops Being Considered By USDA }}</ref>

==== 2,4-D ====
In October 2014 the US EPA registered [[Company:Dow Chemical Company|Dow]]'s Enlist Duo maize, which is genetically modified to be resistant to both [[Chemistry:Glyphosate|glyphosate]] and 2,4-D, in six states.<ref name=ISAAAaad1>{{cite web | work = ISAAA GM Approval Database | url = http://www.isaaa.org/gmapprovaldatabase/gene/default.asp?GeneID=88&Gene=aad-1 | title = Gene list: aad1 | access-date = 27 February 2015 }}</ref><ref>{{cite web | title = EPA Announces Final Decision to Register Enlist Duo, Herbicide Containing 2, 4-D and Glyphosate/Risk assessment ensures protection of human health, including infants, children | work = EPA Press Release | date = 15 October 2014 | url = http://yosemite.epa.gov/opa/admpress.nsf/bd4379a92ceceeac8525735900400c27/72fde554930f3f6985257d7200591180!OpenDocument }}</ref><ref>{{cite web | url = http://www2.epa.gov/ingredients-used-pesticide-products/registration-enlist-duo | title = EPA Documents: Registration of Enlist Duo | date = 18 September 2014 | access-date = 27 February 2015 | archive-date = 16 December 2021 | archive-url = https://web.archive.org/web/20211216074048/https://www.epa.gov/ingredients-used-pesticide-products/registration-enlist-duo | url-status = dead }}</ref> Inserting a bacterial aryloxyalkanoate dioxygenase gene, ''aad1'' makes the corn resistant to 2,4-D.<ref name=ISAAAaad1/><ref>{{cite journal | vauthors = Peterson MA, Shan G, Walsh TA, Wright TR | title = Utility of Aryloxyalkanoate Dioxygenase Transgenes for Development of New Herbicide Resistant Crop Technologies. | journal = Information Systems for Biotechnology | date = May 2011 | url = http://www.isb.vt.edu/news/2011/May/Aryloxyalkanoate-Dioxygenase-Transgenes.pdf }}</ref> The USDA had approved maize and soybeans with the mutation in September 2014.<ref>{{cite web | vauthors = Schultz C | work = The Smithsonian.com | date = 25 September 2014 | url = http://www.smithsonianmag.com/smart-news/usda-approved-new-gm-crop-deal-problem-created-old-gm-crops-180952850/?no-ist | title = The USDA Approved a New GM Crop to Deal With Problems Created by the Old GM Crops }}</ref>

==== Dicamba ====
Monsanto has requested approval for a stacked strain that is tolerant of both glyphosate and [[Chemistry:Dicamba|dicamba]]. The request includes plans for avoiding [[Earth:Pesticide drift|herbicide drift]] to other crops.<ref name="Johnson_2012">{{cite web | vauthors = Johnson WG, Hallett SG, Legleiter TR, Whitford F, Weller SC, Bordelon BP, Lerner BR | display-authors = 6 |title = 2,4-D- and Dicamba-tolerant Crops – Some Facts to Consider|date = November 2012 |url = https://www.extension.purdue.edu/extmedia/ID/ID-453-W.pdf|access-date =3 October 2016|website = Purdue University Extension}}</ref> Significant damage to other non-resistant crops occurred from dicamba formulations intended to reduce volatilization drifting when sprayed on resistant soybeans in 2017.<ref>{{cite web|url=https://cen.acs.org/articles/95/i33/Widespread-crop-damage-dicamba-herbicide.html|title=Widespread crop damage from dicamba herbicide fuels controversy - August 21, 2017 Issue - Vol. 95 Issue 33 - Chemical & Engineering News| vauthors = Bomgardner MM |website=cen.acs.org}}</ref> The newer dicamba formulation labels specify to not spray when average wind speeds are above {{convert|10|-|15|mph|km/h}} to avoid particle drift, average wind speeds below {{convert|3|mph|km/h}} to avoid temperature inversions, and rain or high temperatures are in the next day forecast. However, these conditions typically only occur during June and July for a few hours at a time.<ref>{{cite web|title=Iowa Soybeans: Dicamba – How Many Hours Were Available to Spray in 2017?|url=http://agfax.com/2017/09/19/iowa-soybeans-dicamba-how-many-hours-were-available-to-spray-in-2017/|website=AgFax|access-date=1 October 2017|date=19 September 2017}}</ref><ref>{{cite web|title=Pest & Crop Newsletter|url=https://extension.entm.purdue.edu/pestcrop/2017/Issue23/|website=extension.entm.purdue.edu|publisher=Purdue Cooperative Extension Service|access-date=1 October 2017|language=en}}</ref>

===Pest resistance===

==== Insects ====
Tobacco, corn, rice and some other crops have been engineered to express genes encoding for insecticidal proteins from [[Biology:Bacillus thuringiensis|Bacillus thuringiensis]] (Bt).<ref name="news.google.co.uk">{{cite web | url = https://news.google.com/newspapers?id=A0YyAAAAIBAJ&pg=4631,1776980&dq=bacillus+thuringiensis+potato+1996+approved&hl= | title = Genetically Altered Potato Ok'd For Crops] | work = Lawrence Journal-World | date = 6 May 1995 }}</ref><ref>{{cite journal| vauthors = Vaeck M, Reynaerts A, Höfte H, Jansens S, De Beuckeleer M, Dean C, Zabeau M, Van Montagu M, Leemans J | display-authors = 6 | s2cid = 4310501| title = Transgenic plants protected from insect attack| journal = Nature| volume = 328| issue = 6125| pages = 33–37| year = 1987| doi = 10.1038/328033a0|bibcode = 1987Natur.328...33V }}</ref> The introduction of Bt crops during the period between 1996 and 2005 has been estimated to have reduced the total volume of insecticide active ingredient use in the United States by over 100 thousand tons. This represents a 19.4% reduction in insecticide use.<ref>{{cite web|url = http://www.ars.usda.gov/sp2userfiles/person/4056/naranjoetal.btbook2008.pdf|title = The Present and Future Role of Insect-Resistant Genetically Modified Cotton in IPM|date = 22 April 2008|access-date = 3 December 2015|website = USDA.gov|publisher = United States department of agriculture| vauthors = Naranjo S }}</ref>

In the late 1990s, a [[Biology:Genetically modified potato|genetically modified potato]] that was resistant to the [[Biology:Colorado potato beetle|Colorado potato beetle]] was withdrawn because major buyers rejected it, fearing consumer opposition.<ref name="NYTsimplot"/>

==== Viruses ====
Papaya, potatoes, and squash have been engineered to resist viral pathogens such as [[Biology:Cucumber mosaic virus|cucumber mosaic virus]] which, despite its name, infects a wide variety of plants.<ref>{{cite book |author=National Academy of Sciences |title=Transgenic Plants and World Agriculture |publisher=National Academy Press |location=Washington |year=2001 }}</ref>
Virus resistant papaya were developed in response to a papaya ringspot virus (PRV) outbreak in Hawaii in the late 1990s. They incorporate PRV DNA.<ref name="mhhe">{{cite web | vauthors = Kipp E | work = Botany Global Issues Map | date = February 2000 | url = http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_03.html | title = Genetically Altered Papayas Save the Harvest | archive-url = https://web.archive.org/web/20041213195013/http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_03.html | archive-date = 13 December 2004 }}</ref><ref>{{cite web |url=http://www.hawaiipapaya.com/rainbow.htm |title=The Rainbow Papaya Story |publisher=Hawaii Papaya Industry Association |date=2006 |access-date=27 December 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150107073644/http://www.hawaiipapaya.com/rainbow.htm |archive-date=7 January 2015 }}</ref> By 2010, 80% of Hawaiian papaya plants were genetically modified.<ref>{{cite web | vauthors = Ronald P, McWilliams J | work = The New York Times | date = 14 May 2010 | url = https://www.nytimes.com/2010/05/15/opinion/15ronald.html?_r=0 | title = Genetically Engineered Distortions }}</ref><ref>{{cite web|url=http://www.harc-hspa.com/publications/TF5.pdf |publisher=Hawaii Agriculture Research Center |date=October 2000 |title=Production Of UH Sunup Transgenic Papaya Seed In Hawaii | vauthors = Wenslaff TF, Osgood RB |url-status=dead |archive-url=https://web.archive.org/web/20120331180723/http://www.harc-hspa.com/publications/TF5.pdf |archive-date=31 March 2012 }}</ref>

Potatoes were engineered for resistance to [[Biology:Potato leaf roll virus|potato leaf roll virus]] and Potato virus Y in 1998. Poor sales led to their market withdrawal after three years.<ref>{{cite web|url = https://scholarworks.iupui.edu/bitstream/handle/1805/813/GE%20plant%20virus%20resistance.pdf|title = Genetically Engineered Foods - Plant Virus Resistance|date = 2002|access-date =3 October 2016|website = Cornell Cooperative Extension|publisher = Cornell University}}</ref>

Yellow squash that were resistant to at first two, then three viruses were developed, beginning in the 1990s. The viruses are watermelon, cucumber and zucchini/courgette yellow mosaic. Squash was the second GM crop to be approved by US regulators. The trait was later added to zucchini.<ref>{{cite web|url = http://ucbiotech.org/answer.php?question=15|title = How Many Foods Are Genetically Engineered?|date = 16 February 2012|access-date =3 October 2016|publisher =University of California}}</ref>

Many strains of corn have been developed in recent years to combat the spread of Maize dwarf mosaic virus, a costly virus that causes stunted growth which is carried in [[Biology:Johnson grass|Johnson grass]] and spread by aphid insect vectors. These strands are commercially available although the resistance is not standard among GM corn variants.<ref>{{cite web|url = http://ejbiotechnology.ucv.cl/feedback/proceedings/01/abstracts.html|title = Genetic Engineering for Maize Improvement in China|date = 2009|access-date = 1 December 2015|website = Electronic Journal of Biotechnology| vauthors  = Wang GY }}</ref>

===By-products===

====Drugs====
In 2012, the FDA approved the first [[Biology:Pharming (genetics)|plant-produced pharmaceutical]], a treatment for Gaucher's Disease.<ref>{{cite web | vauthors = Weinreb G, Yeshayahou K | work = Globes | date = 2 May 2012 | url = http://www.globes.co.il/serveen/globes/docview.asp?did=1000745325&fid=1725 | title = FDA approves Protalix Gaucher treatment | archive-url = https://web.archive.org/web/20130529030847/http://www.globes.co.il/serveen/globes/docview.asp?did=1000745325&fid=1725 | archive-date = 29 May 2013 }}</ref> Tobacco plants have been modified to produce therapeutic antibodies.<ref>{{cite web | vauthors = Jha A | date = 14 August 2012 | url = https://www.theguardian.com/technology/2011/aug/14/julian-ma-pharming-tobacco-hiv | title = Julian Ma: I'm growing antibodies in tobacco plants to help prevent HIV | work = The Guardian | access-date = 12 March 2012 }}</ref>

====Biofuel====
[[Biology:Algae|Algae]] is under development for use in [[Earth:Biofuel|biofuel]]s.<ref>{{cite web | vauthors = Carrington D | date = 19 January 2012 | url = https://www.theguardian.com/environment/2012/jan/19/gm-microbe-seaweed-biofuels | title = GM microbe breakthrough paves way for large-scale seaweed farming for biofuels | work = The Guardian | access-date = 12 March 2012 }}</ref> The focus of Microalgae for mass production for biofuels modifying the algae to produce more lipid has become a focus yet will take years to see results due to the cost of this process to extract lipids.<ref>{{Cite journal |author=Prabin Kumar Sharma |author2=Manalisha Saharia |author3=Richa Srivstava |author4=Sanjeev Kumar |author5=Lingaraj Sahoo |date=21 November 2018|title=Tailoring Microalgae for Efficient Biofuel Production|journal=Frontiers in Marine Science|volume=5|doi=10.3389/fmars.2018.00382|doi-access=free}}</ref> Researchers in Singapore were working on GM [[Biology:Jatropha|jatropha]] for biofuel production.<ref>{{cite web|url=http://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=9597|title=Singapore Biodiesel Company Develops GM Jatropha- Crop Biotech Update |website=www.isaaa.org}}</ref> [[Company:Syngenta|Syngenta]] has USDA approval to market a maize trademarked Enogen that has been genetically modified to convert its starch to sugar for [[Chemistry:Ethanol|ethanol]].<ref>{{cite web | vauthors = Lochhead C | work = The San Francisco Chronicle | date = 30 April 2012 | url = http://www.sfgate.com/science/article/Genetically-modified-crops-results-raise-concern-3520087.php | title = Genetically modified crops' results raise concern }}</ref> Some trees have been [[Biology:Genetically modified tree#Lignin alteration|genetically modified]] to either have less [[Biology:Lignin|lignin]], or to express lignin with chemically labile bonds. Lignin is the critical limiting factor when using wood to make bio-ethanol because lignin limits the accessibility of [[Chemistry:Cellulose|cellulose]] [[Chemistry:Microfibril|microfibril]]s to [[Chemistry:Depolymerization|depolymerization]] by [[Biology:Enzyme|enzyme]]s.<ref>{{cite web | date = 2013 | url = http://www.vib.be/en/research/scientists/pages/wout-boerjan-lab.aspx | title = Wout Boerjan Lab | publisher = VIB (Flemish Institute for Biotechnology) Gent | access-date = 27 April 2013 | archive-date = 28 May 2013 | archive-url = https://web.archive.org/web/20130528122325/http://www.vib.be/en/research/scientists/Pages/Wout-Boerjan-Lab.aspx | url-status = dead }}</ref> Besides with trees, the chemically labile lignin bonds are also very useful for cereal crops such as maize,<ref name="pmid28469705">{{cite journal | vauthors = Smith RA, Cass CL, Mazaheri M, Sekhon RS, Heckwolf M, Kaeppler H, de Leon N, Mansfield SD, Kaeppler SM, Sedbrook JC, Karlen SD, Ralph J | title = Suppression of CINNAMOYL-CoA REDUCTASE increases the level of monolignol ferulates incorporated into maize lignins | journal = Biotechnology for Biofuels | volume = 10 | pages = 109 | date = 2017 | pmid = 28469705 | pmc = 5414125 | doi = 10.1186/s13068-017-0793-1 | doi-access = free }}</ref><ref name="pmid24700858">{{cite journal | vauthors = Wilkerson CG, Mansfield SD, Lu F, Withers S, Park JY, Karlen SD, Gonzales-Vigil E, Padmakshan D, Unda F, Rencoret J, Ralph J | s2cid = 25429319 | title = Monolignol ferulate transferase introduces chemically labile linkages into the lignin backbone | journal = Science | volume = 344 | issue = 6179 | pages = 90–3 | date = April 2014 | pmid = 24700858 | doi = 10.1126/science.1250161 | bibcode = 2014Sci...344...90W | hdl = 10261/95743 | hdl-access = free }}
*{{cite magazine |author=Hal Hodson |date=3 April 2014 |title=Redesigned crops could produce far more fuel |magazine=New Scientist |url=https://www.newscientist.com/article/dn25354-redesigned-crops-could-produce-far-more-fuel/ |url-access=registration}}</ref>

====Materials====
Companies and labs are working on plants that can be used to make [[Chemistry:Bioplastic|bioplastic]]s.<ref>{{cite journal | vauthors = van Beilen JB, Poirier Y | title = Production of renewable polymers from crop plants | journal = The Plant Journal | volume = 54 | issue = 4 | pages = 684–701 | date = May 2008 | pmid = 18476872 | doi = 10.1111/j.1365-313x.2008.03431.x | doi-access = free }}</ref> Potatoes that produce industrially useful starches have been developed as well.<ref name="PotatoPro">{{cite news|title=The History and Future of GM Potatoes|url=http://www.potatopro.com/newsletters/20100310.htm|newspaper=PotatoPro Newsletter|date=10 March 2010|access-date=31 August 2012|archive-date=12 October 2013|archive-url=https://web.archive.org/web/20131012033805/http://www.potatopro.com/newsletters/20100310.htm|url-status=dead}}</ref> Oilseed can be modified to produce fatty acids for detergents, substitute fuels and [[Chemistry:Petrochemical|petrochemical]]s.

====Non-pesticide pest management products====
Besides the modified oilcrop above, ''[[Biology:Camelina sativa|Camelina sativa]]'' has also been modified to produce ''[[Biology:Helicoverpa armigera|Helicoverpa armigera]]'' [[Biology:Pheromone|pheromone]]s and is in progress with a ''[[Biology:Spodoptera frugiperda|Spodoptera frugiperda]]'' version. The ''H. armigera'' pheromones have been tested and are effective.<ref name="Cornell-Alliance-Sci">{{cite web |  vauthors = Conrow J | title=GM plant grows insect sex pheromones as alternative to crop pesticides | website=Alliance for Science | date=14 January 2021 | url=http://allianceforscience.cornell.edu/blog/2021/01/gm-plant-grows-insect-sex-pheromones-as-alternative-to-crop-pesticides/ | access-date=17 July 2021}}</ref>

===Bioremediation===
Scientists at the University of York developed a weed (''[[Biology:Arabidopsis thaliana|Arabidopsis thaliana]]'') that contains genes from bacteria that could clean TNT and [[Chemistry:RDX|RDX]]-explosive soil contaminants in 2011.<ref>{{cite news | vauthors = Strange A | date = 20 September 2011 | url = http://www.irishtimes.com/newspaper/ireland/2011/0913/1224304027463.html | title = Scientists engineer plants to eat toxic pollution | newspaper = The Irish Times | access-date = 20 September 2011 }}</ref> 16 million hectares in the US (1.5% of the total surface) are estimated to be contaminated with TNT and RDX. However ''A. thaliana'' was not tough enough for use on military test grounds.<ref name="Growing a grass that loves bombs">{{cite web | vauthors = Chard A | date = 2011 | url = http://www.britishscienceassociation.org/web/News/FestivalNews/Growingagrassthatlovesbombs.htm | title = Growing a grass that loves bombs | work = The British Science Association | access-date = 20 September 2011 | archive-url = https://web.archive.org/web/20120724222425/http://www.britishscienceassociation.org/web/News/FestivalNews/Growingagrassthatlovesbombs.htm | archive-date = 24 July 2012 }}</ref> Modifications in 2016 included [[Biology:Panicum virgatum|switchgrass]] and [[Biology:Agrostis stolonifera|bentgrass]].<ref>{{cite web|url=https://www.sciencedaily.com/releases/2016/11/161122182355.htm|title=New grasses neutralize toxic pollution from bombs, explosives, and munitions| vauthors = Langston J |date=22 November 2016|website=ScienceDaily|access-date=30 November 2016}}</ref>

Genetically modified plants have been used for [[Earth:Bioremediation|bioremediation]] of contaminated soils. [[Chemistry:Mercury (element)|Mercury]], [[Chemistry:Selenium|selenium]] and organic pollutants such as [[Chemistry:Polychlorinated biphenyl|polychlorinated biphenyl]]s (PCBs).<ref name="Growing a grass that loves bombs"/><ref>{{cite journal | vauthors = Meagher RB | title = Phytoremediation of toxic elemental and organic pollutants | journal = Current Opinion in Plant Biology | volume = 3 | issue = 2 | pages = 153–62 | date = April 2000 | pmid = 10712958 | doi = 10.1016/S1369-5266(99)00054-0 }}</ref>

Marine environments are especially vulnerable since pollution such as oil spills are not containable. In addition to anthropogenic pollution, millions of tons of [[Chemistry:Petroleum|petroleum]] annually enter the marine environment from natural seepages. Despite its toxicity, a considerable fraction of petroleum oil entering marine systems is eliminated by the hydrocarbon-degrading activities of microbial communities. Particularly successful is a recently discovered group of specialists, the so-called [[Biology:Hydrocarbonoclastic bacteria|hydrocarbonoclastic bacteria]] (HCCB) that may offer useful genes.<ref name=chapter9>{{cite book|chapter-url=http://www.horizonpress.com/biod| vauthors = Martins VA |year=2008|chapter=Genomic Insights into Oil Biodegradation in Marine Systems|title=Microbial Biodegradation: Genomics and Molecular Biology|publisher=Caister Academic Press|url=https://archive.org/details/microbialbiodegr0000unse|isbn=978-1-904455-17-2|url-access=registration}}{{Dead link|date=September 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

===Asexual reproduction===

Crops such as [[Biology:Maize|maize]] reproduce sexually each year. This randomizes which genes get propagated to the next generation, meaning that desirable traits can be lost. To maintain a high-quality crop, some farmers purchase seeds every year. Typically, the seed company maintains two inbred varieties and crosses them into a [[Biology:Hybrid|hybrid]] strain that is then sold. Related plants like [[Biology:Sorghum|sorghum]] and gamma grass are able to perform [[Biology:Apomixis|apomixis]], a form of asexual reproduction that keeps the plant's DNA intact. This trait is apparently controlled by a single dominant gene, but traditional breeding has been unsuccessful in creating asexually-reproducing maize. Genetic engineering offers another route to this goal. Successful modification would allow farmers to replant harvested seeds that retain desirable traits, rather than relying on purchased seed.<ref>{{cite journal|date=1 March 2003|periodical=Technology Review| vauthors = Daniel C |title=Corn That Clones Itself|url=http://www.technologyreview.com/featuredstory/401826/corn-that-clones-itself/}}</ref>

===Other===
Genetic modifications to some crops also exist, which make it easier to process the crop, i.e. by growing in a more compact form.<ref name="pmid31873217">{{cite journal | vauthors = Kwon CT, Heo J, Lemmon ZH, Capua Y, Hutton SF, Van Eck J, Park SJ, Lippman ZB | s2cid = 209464229 | title = Rapid customization of Solanaceae fruit crops for urban agriculture | journal = Nature Biotechnology | volume = 38 | issue = 2 | pages = 182–188 | date = February 2020 | pmid = 31873217 | doi = 10.1038/s41587-019-0361-2 }}</ref> Also, some crops (such as tomatoes) have been genetic modified to contain no seed at all.<ref name="pmid28360425">{{cite journal | vauthors = Ueta R, Abe C, Watanabe T, Sugano SS, Ishihara R, Ezura H, Osakabe Y, Osakabe K | title = Rapid breeding of parthenocarpic tomato plants using CRISPR/Cas9 | journal = Scientific Reports | volume = 7 | issue = 1 | pages = 507 | date = March 2017 | pmid = 28360425 | pmc = 5428692 | doi = 10.1038/s41598-017-00501-4 | bibcode = 2017NatSR...7..507U}}
*{{cite magazine |author=Alice Klein |date=11 April 2017 |title=Gene editing opens doors to seedless fruit with no need for bees |magazine=New Scientist |url=https://www.newscientist.com/article/2127640-gene-editing-opens-doors-to-seedless-fruit-with-no-need-for-bees/ |url-access=registration}}</ref>

==Crops==

===Herbicide tolerance===

{| style="margin:auto; text-align:center" class="wikitable sortable"
|-
! Crop
!Use
! Countries approved in
! First approved<ref name="isaaa3">{{cite web|title = GM Crops List {{!}} GM Approval Database- ISAAA.org|url = http://www.isaaa.org/gmapprovaldatabase/cropslist/|website = www.isaaa.org|access-date = 30 January 2016}}</ref>
! Notes
|-
|[[Biology:Alfalfa#Genetic modification|Alfalfa]]
|Animal feed<ref name="Time">{{cite magazine|title = All the GMOs Approved In the U.S.|url = http://time.com/3840073/gmo-food-charts/|magazine = {{wipe|Time (magazine)}}|access-date = 11 February 2016}}</ref>
| US
| 2005
|Approval withdrawn in 2007<ref>{{cite web|title = Lucerne - GMO Database|url = http://www.gmo-compass.org/eng/database/plants/51.lucerne.html|website = www.gmo-compass.org|access-date = 11 February 2016|last = www.gmo-compass.org|archive-url = https://web.archive.org/web/20160702052804/http://www.gmo-compass.org/eng/database/plants/51.lucerne.html|archive-date = 2 July 2016|url-status = dead|df = dmy-all}}</ref> and then re-approved in 2011<ref>{{cite news|title = UPDATE 3-U.S. farmers get approval to plant GMO alfalfa|url = https://www.reuters.com/article/gmo-alfalfa-usda-idUSN2727513020110127|newspaper = Reuters|date = 27 January 2011|access-date = 11 February 2016}}</ref>
|-
| rowspan="3" |[[Biology:Genetically modified canola|Canola]]
| rowspan="3" |Cooking oil

Margarine

[[Chemistry:Emulsion#In food|Emulsifiers in packaged foods]]<ref name="Time" />
| Australia
| 2003
|
|-
| Canada
| 1995
|
|-
| US
| 1995
|
|-
| rowspan="9" | Cotton
| rowspan="9" |Fiber<br />Cottonseed oil<br />Animal feed<ref name="Time" />
| Argentina
| 2001
|
|-
| Australia
| 2002
|
|-
| Brazil
| 2008
|
|-
| Colombia
| 2004
|
|-
| Costa Rica
| 2008
|
|-
| Mexico
| 2000
|
|-
| Paraguay
| 2013
|
|-
| South Africa
| 2000
|
|-
| US
| 1994
|
|-
| rowspan="12" |Maize
| rowspan="12" |Animal feed
high-fructose corn syrup

[[Chemistry:Corn starch|corn starch]]<ref name="Time" />
| Argentina
| 1998
|
|-
| Brazil
| 2007
|
|-
| Canada
| 1996
|
|-
| Colombia
| 2007
|
|-
| Cuba
| 2011
|
|-
| European Union
| 1998
| Grown in Portugal, Spain, Czech Republic, Slovakia and Romania<ref name="ISAAA Infographic">{{cite web
| url = http://www.isaaa.org/resources/publications/briefs/49/infographic/default.asp
| title = Infographics: Global Status of Commercialized Biotech/GM Crops: 2014 - ISAAA Brief 49-2014 {{!}} ISAAA.org
| website = www.isaaa.org
| access-date = 11 February 2016
}}</ref>
|-
| Honduras
| 2001
|
|-
| Paraguay
| 2012
|
|-
| Philippines
| 2002
|
|-
| South Africa
| 2002
|
|-
| US
| 1995
|
|-
| Uruguay
| 2003
|
|-
| rowspan="11" |Soybean
| rowspan="11" |Animal feed
Soybean oil<ref name="Time" />
|Argentina
|1996
|
|-
|Bolivia
|2005
|
|-
|Brazil
|1998
|
|-
|Canada
|1995
|
|-
|Chile
|2007
|
|-
|Costa Rica
|2001
|
|-
|Mexico
|1996
|
|-
|Paraguay
|2004
|
|-
|South Africa
|2001
|
|-
|US
|1993
|
|-
|Uruguay
|1996
|
|-
| rowspan="2" |Sugar Beet
| rowspan="2" |Food<ref name="WSJ" />
|Canada
|2001
|
|-
|US
|1998
|Commercialised 2007,<ref>{{cite news|title = Round 2 for Biotech Beets|url = https://www.nytimes.com/2007/11/27/business/27sugar.html|newspaper = The New York Times|date = 27 November 2007|access-date = 15 February 2016|issn = 0362-4331| vauthors = Pollack A }}</ref> production blocked 2010, resumed 2011.<ref name="WSJ">{{cite news|title = Modified Beet Gets New Life|url = https://www.wsj.com/articles/SB10001424052748704709304576124454083334630|newspaper = Wall Street Journal|access-date = 15 February 2016| vauthors = Kilman S }}</ref>
|}

===Insect resistance===

{| style="margin:auto; text-align:center" class="wikitable sortable"
|-
! Crop
!Use
! Countries approved in
! First approved<ref name="isaaa3"/>
! Notes
|-
| rowspan="15" |Cotton
| rowspan="15" |Fiber<br />Cottonseed oil<br />Animal feed<ref name="Time" />
| Argentina
| 1998
|
|-
| Australia
| 2003
|
|-
| Brazil
| 2005
|
|-
|Burkina Faso
|2009
|
|-
| China
| 1997
|
|-
| Colombia
| 2003
|
|-
| Costa Rica
| 2008
|
|-
| India
| 2002
|Largest producer of Bt cotton<ref name="Facts India">{{cite web|url=http://www.isaaa.org/resources/publications/biotech_country_facts_and_trends/download/Facts%20and%20Trends%20-%20India.pdf|title=Facts and trends - India |publisher=International Service for the Acquisition of Agri-biotech Applications}}</ref>
|-
| Mexico
| 1996
|
|-
| Myanmar
| 2006<ref group="N" name="Economist_2014">No official public documentation available</ref>
|
|-
| Pakistan
| 2010<ref group="N" name="Economist_2014" />
|
|-
| Paraguay
| 2007
|
|-
| South Africa
| 1997
|
|-
| Sudan
| 2012
|
|-
| US
| 1995
|
|-
| [[Biology:Bt brinjal|Eggplant]]
|Food
| Bangladesh
| 2013
|12 ha planted on 120 farms in 2014<ref name="ISAAA Summary 14">{{cite web|url=http://www.isaaa.org/resources/publications/briefs/49/executivesummary/default.asp|title=Executive Summary: Global Status of Commercialized Biotech/GM Crops: 2014 - ISAAA Brief 49-2014 {{!}} ISAAA.org|website=www.isaaa.org|access-date=16 February 2016}}</ref>
|-
| rowspan="9" |Maize
| rowspan="9" |Animal feed
high-fructose corn syrup

[[Chemistry:Corn starch|corn starch]]<ref name="Time" />
|Argentina
|1998
|
|-
|Brazil
|2005
|
|-
|Colombia
|2003
|
|-
|Mexico
|1996
|Centre of origin for maize<ref name="Facts Mexico">
{{cite web|url=http://www.isaaa.org/resources/publications/biotech_country_facts_and_trends/download/Facts%20and%20Trends%20-%20Mexico.pdf|title=Facts and trends-Mexico |publisher=International Service for the Acquisition of Agri-biotech Applications}}

</ref>
|-
|Paraguay
|2007
|
|-
|Philippines
|2002
|
|-
|South Africa
|1997
|
|-
|Uruguay
|2003
|
|-
|US
|1995
|
|-
|Poplar
|Tree
|China
|1998
|543 ha of bt poplar planted in 2014<ref name="Facts China">{{cite web|url=http://www.isaaa.org/resources/publications/biotech_country_facts_and_trends/download/Facts%20and%20Trends%20-%20China.pdf|title=Facts and trends- China |publisher=International Service for the Acquisition of Agri-biotech Applications}}</ref>
|}

===Other modified traits===
{| style="margin:auto; text-align:center" class="wikitable sortable"
|-
! Crop
!Use
! Trait
! Countries approved in
! First approved<ref name="isaaa3"/>
! Notes
|-
| rowspan="3" | [[Biology:Genetically modified canola|Canola]]
| rowspan="3" |Cooking oil

Margarine

Emulsifiers in packaged foods<ref name="Time" />
| rowspan="2" | High laurate canola
| Canada
| 1996
|
|-
| US
| 1994
|
|-
| [[Biology:Phytase|Phytase]] production
| US
| 1998
|
|-
| rowspan="8" |Carnation
| rowspan="8" |Ornamental
| rowspan="2" |Delayed [[Biology:Senescence|senescence]]
|Australia
|1995
|
|-
|Norway
|1998
|
|-
| rowspan="6" | Modified flower colour
| Australia
| 1995
|
|-
| Colombia
| 2000
|In 2014 4 ha were grown in greenhouses for export<ref name="Facts_Colombia">{{cite web|url=http://www.isaaa.org/resources/publications/biotech_country_facts_and_trends/download/Facts%20and%20Trends%20-%20Colombia.pdf|title=Facts and trends - Colombia |publisher=International Service for the Acquisition of Agri-biotech Applications}}</ref>
|-
| European Union
| 1998
|Two events expired 2008, another approved 2007
|-
| Japan
| 2004
|
|-
| Malaysia
| 2012
|For ornamental purposes
|-
| Norway
| 1997
|
|-
| rowspan="4" |Maize
| rowspan="4" |Animal feed
high-fructose corn syrup

[[Chemistry:Corn starch|corn starch]]<ref name="Time" />
| rowspan="2" | Increased [[Chemistry:Lysine|lysine]]
| Canada
| 2006
|
|-
| US
| 2006
|
|-
| rowspan="2" |[[Biology:Drought tolerance|Drought tolerance]]
|Canada
|2010
|
|-
|US
|2011
|
|-
| rowspan="2" |Papaya
| rowspan="2" |Food<ref name="Time" />
| rowspan="2" |Virus resistance
|China
|2006
|
|-
|US
|1996
|Mostly grown in Hawaii<ref name="Time" />
|-
|Petunia
|Ornamental
|Modified flower colour
|China
|1997<ref>{{cite book|title=Genetically Modified Food and Global Welfare (Frontiers of Economics and Globalization)|url=https://archive.org/details/geneticallymodif00mosc|url-access=limited | publisher=Emerald Group Publishing Limited|year=2011|isbn=978-0857247575| veditors = Carter C, Moschini GC, Sheldon I |location=United Kingdom|page=[https://archive.org/details/geneticallymodif00mosc/page/n106 89]}}</ref>
|
|-
| rowspan="3" |[[Biology:Genetically modified potato|Potato]]
| rowspan="2" |Food<ref name="Time" />
| rowspan="2" |Virus resistance
|Canada
|1999
|
|-
|US
|1997
|
|-
|Industrial<ref name="theguardian1">{{cite news|title = GM potato to be grown in Europe|url = https://www.theguardian.com/environment/2010/mar/03/eu-approves-gm-food-potato|newspaper = The Guardian|date = 3 March 2010|access-date = 15 February 2016|issn = 0261-3077|language = en-GB| agency = Associated Press }}</ref>
|Modified [[Chemistry:Starch|starch]]
|US
|2014
|
|-
| rowspan="4" |[[Biology:Blue rose|Rose]]
| rowspan="4" |Ornamental
| rowspan="4" |Modified flower colour
|Australia
|2009
|Surrendered renewal
|-
|Colombia
|2010<ref group="N">No public documents</ref>
|Greenhouse cultivation for export only.
|-
|Japan
|2008
|
|-
|US
|2011
|
|-
| rowspan="5" |Soybean
| rowspan="5" |Animal feed
Soybean oil<ref name="Time" />
| rowspan="3" |Increased [[Chemistry:Oleic acid|oleic acid]] production
|Argentina
|2015
|
|-
|Canada
|2000
|
|-
|US
|1997
|
|-
| rowspan="2" |[[Chemistry:Stearidonic acid|Stearidonic acid]] production
|Canada
|2011
|
|-
|US
|2011
|
|-
|Squash
|Food<ref name="Time" />
|Virus resistance
|US
|1994
|
|-
|Sugar Cane
|Food
|Drought tolerance
|Indonesia
|2013
|Environmental certificate only
|-
|[[Biology:Tobacco|Tobacco]]
|Cigarettes
|Nicotine reduction
|US
|2002
|
|}

===GM ''Camelina''===
Several modifications of ''[[Biology:Camelina sativa|Camelina sativa]]'' have been done, see §Edible oils and §Non-pesticide pest management products above.

=== Development ===
The number of USDA-approved field releases for testing grew from 4 in 1985 to 1,194 in 2002 and averaged around 800 per year thereafter. The number of sites per release and the number of gene constructs (ways that the gene of interest is packaged together with other elements)&nbsp;– have rapidly increased since 2005. Releases with agronomic properties (such as drought resistance) jumped from 1,043 in 2005 to 5,190 in 2013. As of September 2013, about 7,800 releases had been approved for corn, more than 2,200 for soybeans, more than 1,100 for cotton, and about 900 for potatoes. Releases were approved for herbicide tolerance (6,772 releases), insect resistance (4,809), product quality such as flavor or nutrition (4,896), agronomic properties like drought resistance (5,190), and virus/fungal resistance (2,616). The institutions with the most authorized field releases include Monsanto with 6,782, Pioneer/DuPont with 1,405, Syngenta with 565, and USDA's Agricultural Research Service with 370. As of September 2013 USDA had received proposals for releasing GM rice, squash, plum, rose, tobacco, flax, and chicory.<ref name="ERS_2016">{{cite web|url=http://www.ers.usda.gov/media/1282242/err162_summary.pdf|title=Genetically Engineered Crops in the United States (summary)|date=February 2014|access-date=3 October 2016|website=Economic Research Service USDA|publisher=United States Department of Agriculture| vauthors = Fernandez-Cornejo J, Wechsler S, Livingston M, Mitchell L |page=2 |archive-url= https://web.archive.org/web/20141127005201/http://www.ers.usda.gov/media/1282242/err162_summary.pdf |archive-date=27 November 2014|url-status=dead}}</ref>

==Farming practices==
===Resistance===

====''Bacillus thuringiensis''====
Constant exposure to a toxin creates [[Biology:Evolutionary pressure|evolutionary pressure]] for pests resistant to that toxin.<ref>{{cite web|last=Charles|first=Dan|date=29 October 2020|title=As Biotech crops lose their power, scientist push for new restrictions|url=http://www.npr.org/2020/10/29/927111009/as-biotech-crops-lose-their-power-scientists-push-for-new-restrictions |website=NPR}}</ref> Over-reliance on [[Chemistry:Glyphosate|glyphosate]] and a reduction in the diversity of weed management practices allowed the spread of glyphosate resistance in 14 weed species in the US,<ref name="ERS_2016"/> and in soybeans.<ref name=perry/>

To reduce resistance to ''[[Biology:Bacillus thuringiensis|Bacillus thuringiensis]]'' (Bt) crops, the 1996 commercialization of transgenic cotton and maize came with a management strategy to prevent insects from becoming resistant. Insect resistance management plans are mandatory for Bt crops. The aim is to encourage a large population of pests so that any (recessive) resistance genes are diluted within the population. Resistance lowers evolutionary fitness in the absence of the stressor, Bt. In refuges, non-resistant strains outcompete resistant ones.<ref>{{cite journal | vauthors = Tabashnik BE, Carrière Y, Dennehy TJ, Morin S, Sisterson MS, Roush RT, Shelton AM, Zhao JZ | s2cid = 31944651 | display-authors = 6 | title = Insect resistance to transgenic Bt crops: lessons from the laboratory and field | journal = Journal of Economic Entomology | volume = 96 | issue = 4 | pages = 1031–8 | date = August 2003 | pmid = 14503572 | doi = 10.1603/0022-0493-96.4.1031 | url = http://www.gmo-safety.eu/pdf/dokumente/bt_tabashnik.pdf | url-status = dead | archive-url = https://web.archive.org/web/20130314215007/http://www.gmo-safety.eu/pdf/dokumente/bt_tabashnik.pdf | df = dmy-all | archive-date = 14 March 2013 }}</ref>

With sufficiently high levels of transgene expression, nearly all of the heterozygotes (S/s), i.e., the largest segment of the pest population carrying a resistance allele, will be killed before maturation, thus preventing transmission of the resistance gene to their progeny.<ref>{{cite journal | vauthors =Roush RT | year= 1997 | title=Bt-transgenic crops: just another pretty insecticide or a chance for a new start in the resistance management? | journal = Pestic. Sci. | volume = 51 | issue =3 | pages=328–34 | doi =10.1002/(SICI)1096-9063(199711)51:3<328::AID-PS650>3.0.CO;2-B}}</ref> Refuges (i. e., fields of nontransgenic plants) adjacent to transgenic fields increases the likelihood that homozygous resistant (s/s) individuals and any surviving heterozygotes will mate with susceptible (S/S) individuals from the refuge, instead of with other individuals carrying the resistance allele. As a result, the resistance gene frequency in the population remains lower.

Complicating factors can affect the success of the high-dose/refuge strategy. For example, if the temperature is not ideal, thermal stress can lower Bt toxin production and leave the plant more susceptible. More importantly, reduced late-season expression has been documented, possibly resulting from [[Biology:DNA methylation|DNA methylation]] of the promoter.<ref>{{cite journal | year= 2007 | title= Variability of Endotoxin Expression in Bt Transgenic Cotton | journal= Journal of Agronomy and Crop Science | volume= 193 | pages=21–29 | doi=10.1111/j.1439-037X.2006.00240.x | vauthors = Dong HZ, Li WJ | issue= 1 | bibcode= 2007JAgCS.193...21D }}</ref> The success of the high-dose/refuge strategy has successfully maintained the value of Bt crops. This success has depended on factors independent of management strategy, including low initial resistance allele frequencies, fitness costs associated with resistance, and the abundance of non-Bt host plants outside the refuges.<ref>{{cite journal | vauthors = Tabashnik BE, Carrière Y, Dennehy TJ, Morin S, Sisterson MS, Roush RT, Shelton AM, Zhao JZ | s2cid = 31944651 | display-authors = 6 | title = Insect resistance to transgenic Bt crops: lessons from the laboratory and field | journal = Journal of Economic Entomology | volume = 96 | issue = 4 | pages = 1031–8 | date = August 2003 | pmid = 14503572 | doi = 10.1603/0022-0493-96.4.1031 | doi-access = free }}</ref>

Companies that produce Bt seed are introducing strains with multiple Bt proteins. Monsanto did this with Bt cotton in India, where the product was rapidly adopted.<ref>{{cite web|url=http://www.monsanto.com/newsviews/Pages/india-pink-bollworm.aspx|title=Monsanto - Pink Bollworm Resistance to GM Cotton in India|author=APPDMZ\ccvivr}}</ref> Monsanto has also; in an attempt to simplify the process of implementing refuges in fields to comply with Insect Resistance Management(IRM) policies and prevent irresponsible planting practices; begun marketing seed bags with a set proportion of refuge (non-transgenic) seeds mixed in with the Bt seeds being sold. Coined "Refuge-In-a-Bag" (RIB), this practice is intended to increase farmer compliance with refuge requirements and reduce additional labor needed at planting from having separate Bt and refuge seed bags on hand.<ref>{{cite web|title = The Real Deal: Explaining Monsanto's Refuge-in-the-Bag Concept|url = http://www.monsanto.com/newsviews/pages/explaining-refuge-in-the-bag-concept.aspx|archive-url = https://web.archive.org/web/20100910040406/http://www.monsanto.com/newsviews/Pages/Explaining-Refuge-in-the-Bag-Concept.aspx|url-status = dead|archive-date = 10 September 2010|website = www.monsanto.com|access-date = 3 December 2015}}</ref> This strategy is likely to reduce the likelihood of Bt-resistance occurring for corn rootworm, but may increase the risk of resistance for lepidopteran corn pests, such as [[Biology:European corn borer|European corn borer]]. Increased concerns for resistance with seed mixtures include partially resistant larvae on a Bt plant being able to move to a susceptible plant to survive or cross pollination of refuge pollen on to Bt plants that can lower the amount of Bt expressed in kernels for ear feeding insects.<ref name="Siegfried">{{cite journal | vauthors = Siegfried BD, Hellmich RL | title = Understanding successful resistance management: the European corn borer and Bt corn in the United States | journal = GM Crops & Food | volume = 3 | issue = 3 | pages = 184–93 | year = 2012 | pmid = 22688691 | doi = 10.4161/gmcr.20715 | url = http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1060&context=ent_pubs | doi-access = free }}</ref><ref name="Devos">{{cite journal | vauthors = Devos Y, Meihls LN, Kiss J, Hibbard BE | s2cid = 10821353 | title = Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations | journal = Transgenic Research | volume = 22 | issue = 2 | pages = 269–99 | date = April 2013 | pmid = 23011587 | doi = 10.1007/s11248-012-9657-4 | url = http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=2247&context=usdaarsfacpub }}</ref>

====Herbicide resistance====
Best management practices (BMPs) to control weeds may help delay resistance. BMPs include applying multiple herbicides with different modes of action, rotating crops, planting weed-free seed, scouting fields routinely, cleaning equipment to reduce the transmission of weeds to other fields, and maintaining field borders.<ref name="ERS_2016"/> The most widely planted GM crops are designed to tolerate herbicides. By 2006 some weed populations had evolved to tolerate some of the same herbicides. Palmer amaranth is a weed that competes with cotton. A native of the southwestern US, it traveled east and was first found resistant to glyphosate in 2006, less than 10 years after GM cotton was introduced.<ref>{{cite journal | vauthors = Culpepper AS, Grey TL, Vencill WK, Kichler JM, Webster TM, Brown SM, York AC, Davis JW, Hanna WW | display-authors = 6 |title=Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) confirmed in Georgia|volume=54|issue=4|pages=620–26|year=2006|journal=Weed Science|doi=10.1614/ws-06-001r.1 | s2cid = 56236569 }}</ref><ref>{{cite journal | vauthors = Gallant A |title=Pigweed in the Cotton: A superweed invades Georgia|journal=Modern Farmer}}</ref>

=== Plant protection ===
Farmers generally use less insecticide when they plant Bt-resistant crops. Insecticide use on corn farms declined from 0.21 pound per planted acre in 1995 to 0.02 pound in 2010. This is consistent with the decline in [[Biology:European corn borer|European corn borer]] populations as a direct result of Bt corn and cotton. The establishment of minimum refuge requirements helped delay the evolution of Bt resistance. However, resistance appears to be developing to some Bt traits in some areas.<ref name="ERS_2016"/> In Columbia, GM cotton has reduced insecticide usage by 25% and herbicide usage by 5%, and GM corn has reduced insecticide and herbicide usage by 66% and 13%, respectively.<ref name=":0">{{Cite journal |last=Brookes |first=Graham |date=2020-07-02 |title=Genetically modified (GM) crop use in Colombia: farm level economic and environmental contributions |journal=GM Crops & Food |language=en |volume=11 |issue=3 |pages=140–153 |doi=10.1080/21645698.2020.1715156 |issn=2164-5698 |pmc=7518743 |pmid=32008444}}</ref>

===Tillage===
By leaving at least 30% of crop residue on the soil surface from harvest through planting, conservation tillage reduces soil erosion from wind and water, increases water retention, and reduces soil degradation as well as water and chemical runoff. In addition, conservation tillage reduces the carbon footprint of agriculture.<ref name=till>{{cite journal|url = http://www.agbioforum.org/v15n3/v15n3a01-fernandez-cornejo.htm|title = Conservation Tillage, Herbicide Use, and Genetically Engineered Crops in the United States: The Case of Soybeans|vauthors = Fernandez-Cornejo J, Hallahan C, Nehring RF, Wechsler S, Grube A|date = 2014|journal = AgBioForum|access-date = 3 October 2016|volume = 15|issue = 3|archive-date = 6 June 2016|archive-url = https://web.archive.org/web/20160606131724/http://www.agbioforum.org/v15n3/v15n3a01-fernandez-cornejo.htm|url-status = dead}}</ref> A 2014 review covering 12 states from 1996 to 2006, found that a 1% increase in herbicde-tolerant (HT) soybean adoption leads to a 0.21% increase in conservation tillage and a 0.3% decrease in quality-adjusted herbicide use.<ref name=till/>

=== Greenhouse gas emissions ===
Combined features of increased yield, decreased land use, reduced use of fertilizer and reduced farming machinery use create a feedback loop that reduces carbon emissions related to farming. These reductions have been estimated at 7.5% of total agricultural emissions in the EU or 33 millions tons of {{CO2}}<ref>{{Cite journal |last1=Kovak |first1=Emma |last2=Blaustein-Rejto |first2=Dan |last3=Qaim |first3=Matin |date=8 February 2022 |title=Genetically modified crops support climate change mitigation |journal=Trends in Plant Science |language=English |volume=27 |issue=7 |pages=627–629 |doi=10.1016/j.tplants.2022.01.004 |issn=1360-1385 |pmid=35148945 |doi-access=free}}</ref> and an estimated 8.76 million tons of {{CO2}} in Columbia.<ref name=":02">{{Cite journal |last=Brookes |first=Graham |date=2020-07-02 |title=Genetically modified (GM) crop use in Colombia: farm level economic and environmental contributions |journal=GM Crops & Food |language=en |volume=11 |issue=3 |pages=140–153 |doi=10.1080/21645698.2020.1715156 |issn=2164-5698 |pmc=7518743 |pmid=32008444}}</ref>

=== Drought tolerance ===
The use of drought tolerant crops can increase yield in water-scarce locations, making farming possible in new areas. The adoption of drought tolerant maize in Ghana was shown to increase yield by more than 150% and boost commercialization intensity, although it did not significantly affect farm income.<ref>{{Cite journal |last1=Martey |first1=Edward |last2=Etwire |first2=Prince M. |last3=Kuwornu |first3=John K. M. |date=2020-05-01 |title=Economic impacts of smallholder farmers' adoption of drought-tolerant maize varieties |url=https://www.sciencedirect.com/science/article/pii/S0264837718304538 |journal=Land Use Policy |volume=94 |pages=104524 |doi=10.1016/j.landusepol.2020.104524 |s2cid=213380155 |issn=0264-8377}}</ref>

==Regulation==

The regulation of genetic engineering concerns the approaches taken by governments to assess and manage the risks associated with the development and release of genetically modified crops. There are differences in the regulation of GM crops between countries, with some of the most marked differences occurring between the US and Europe. Regulation varies in a given country depending on the intended use of each product. For example, a crop not intended for food use is generally not reviewed by authorities responsible for food safety.<ref name="Wesseler-2011">{{cite book | vauthors = Wesseler J, Kalaitzandonakes N | date = 2011 | chapter = Present and Future EU GMO policy. | veditors = Oskam A, Meesters G, Silvis H | title = EU Policy for Agriculture, Food and Rural Areas | edition = Second | pages = 23–323 | location = Wageningen | publisher = Wageningen Academic Publishers }}</ref><ref name="Beckmann-2011">{{cite book | vauthors = Beckmann V, Soregaroli C, Wesseler J | date = 2011 | chapter = Coexistence of genetically modified (GM) and non-modified (non GM) crops: Are the two main property rights regimes equivalent with respect to the coexistence value? | title = Genetically modified food and global welfare | veditors = Carter C, Moschini GC, Sheldon I | pages = 201–224 | volume = 10 | series = Frontiers of Economics and Globalization Series | location = Bingley, UK | publisher = Emerald Group Publishing }}</ref>

== Production ==
[[File:World map GMO production.svg|thumb|350px|GM crops production in the World (ISAAA Brief 2019)
{{legend|#803300|More than 10 million hectares}}
{{legend|#D45500|Between 50,000 and 10 million hectares}}
{{legend|#FF9955|Less than 50,000 hectares}}
{{legend|#b9b9b9|No biotech crops}}]]

In 2013, GM crops were planted in 27 countries; 19 were developing countries and 8 were developed countries. 2013 was the second year in which developing countries grew a majority (54%) of the total GM harvest. 18 million farmers grew GM crops; around 90% were small-holding farmers in developing countries.<ref name="James2013"/>

{| class="wikitable sortable"
|-
! Country !! 2013– GM planted area (million hectares)<ref name="James2012">{{cite web | work = ISAAA 2012 Annual Report | url = http://www.isaaa.org/resources/publications/briefs/44/executivesummary/default.asp | title = Executive Summary }}</ref>!! Biotech crops
|-
| US || 70.1 || Maize, Soybean, Cotton, Canola, Sugarbeet, Alfalfa, Papaya, Squash
|-
| Brazil || 40.3 || Soybean, Maize, Cotton
|-
| Argentina || 24.4 || Soybean, Maize, Cotton
|-
| India || 11.0 ||  Cotton
|-
| Canada || 10.8 || Canola, Maize, Soybean, Sugarbeet

|-
| Total || 175.2 ||  ----
|}

The United States Department of Agriculture (USDA) reports every year on the total area of GM crop varieties planted in the United States.<ref>{{cite book | vauthors = Fernandez-Cornejo J | title=Adoption of Genetically Engineered Crops in the U.S. | url=http://www.ers.usda.gov/Data/BiotechCrops/ | archive-url=https://web.archive.org/web/20090905222630/http://www.ers.usda.gov/Data/BiotechCrops/ | archive-date=5 September 2009 | url-status=dead | access-date=24 September 2009 | series=Data Sets | date=1 July 2009 | oclc=53942168 |publisher=Economic Research Service, United States Department of Agriculture}}</ref><ref>{{cite web | date = 14 July 2014 | url = http://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us.aspx#.U-I-JONdWSo | title = Adoption of Genetically Engineered Crops in the U.S. | work = USDA, Economic Research Service | access-date = 6 August 2014 }}</ref> According to [[Organization:National Agricultural Statistics Service|National Agricultural Statistics Service]], the states published in these tables represent 81–86 percent of all corn planted area, 88–90 percent of all soybean planted area, and 81–93 percent of all upland cotton planted area (depending on the year).

Global estimates are produced by the International Service for the Acquisition of Agri-biotech Applications (ISAAA) and can be found in their annual reports, "Global Status of Commercialized Transgenic Crops".<ref name="James2013" /><ref name="James2007">{{cite book | vauthors = James C | series = ISAAA Briefs | volume = 37 | year = 2007 | title = G lobal Status of Commercialized Biotech/GM Crops: 2007 | chapter-url = http://www.isaaa.org/Resources/Publications/briefs/37/executivesummary/default.html | archive-url = https://web.archive.org/web/20080606010604/http://www.isaaa.org/Resources/Publications/briefs/37/executivesummary/default.html | archive-date = 6 June 2008 | access-date = 24 September 2009 | publisher = The International Service for the Acquisition of Agri-biotech Applications (ISAAA) | isbn = 978-1-892456-42-7 | oclc = 262649526 | chapter = Executive Summary }}</ref>

Farmers have widely adopted GM technology (see figure). Between 1996 and 2013, the total surface area of land cultivated with GM crops increased by a factor of 100, from {{convert|17000|km2|acre|sp=us}} to 1,750,000&nbsp;km<sup>2</sup> (432 million acres).<ref name="James2013" /> 10% of the world's arable land was planted with GM crops in 2010.<ref name="James2011">{{cite web|url=http://www.isaaa.org/resources/publications/briefs/43/executivesummary/default.asp|title=ISAAA Brief 43, Global Status of Commercialized Biotech/GM Crops: 2011| vauthors = James C |year=2011|work=ISAAA Briefs|publisher=International Service for the Acquisition of Agri-biotech Applications (ISAAA)|location=Ithaca, New York|access-date=2 June 2012}}</ref> As of 2011, 11 different transgenic crops were grown commercially on 395 million acres (160 million hectares) in 29 countries such as the US, Brazil, Argentina, India, Canada, China, Paraguay, Pakistan, South Africa, Uruguay, Bolivia, Australia, Philippines, Myanmar, Burkina Faso, Mexico and Spain.<ref name="James2011" /> One of the key reasons for this widespread adoption is the perceived economic benefit the technology brings to farmers. For example, the system of planting glyphosate-resistant seed and then applying glyphosate once plants emerged provided farmers with the opportunity to dramatically increase the yield from a given plot of land, since this allowed them to plant rows closer together. Without it, farmers had to plant rows far enough apart to control post-emergent weeds with mechanical tillage.<ref name="HighPlainsJ">{{cite web|url=http://www.hpj.com/archives/roundup-ready-soybean-trait-patent-nears-expiration-in/article_8c7a83b7-2a37-5291-9204-2633eb3e4c0d.html |title=Roundup Ready soybean trait patent nears expiration in 2014 |publisher=Hpj.com |access-date=6 June 2016}}</ref> Likewise, using Bt seeds means that farmers do not have to purchase insecticides, and then invest time, fuel, and equipment in applying them. However critics have disputed whether yields are higher and whether chemical use is less, with GM crops. See [[Philosophy:Genetically modified food controversies|Genetically modified food controversies]] article for information.

[[File:Gmo acreage world 2009.PNG|thumb|350px|Land area used for genetically modified crops by country (1996–2009), in millions of hectares. In 2011, the land area used was 160 million hectares, or 1.6 million square kilometers.<ref name="James2011" />]]

In the US, by 2014, 94% of the planted area of soybeans, 96% of cotton and 93% of corn were genetically modified varieties.<ref name="USDA2014">{{cite web|url=http://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us.aspx|title=USDA ERS - Adoption of Genetically Engineered Crops in the U.S.|website=www.ers.usda.gov}}</ref><ref name="NASS2010">{{cite web | url = http://usda.mannlib.cornell.edu/usda/nass/Acre/2010s/2010/Acre-06-30-2010.pdf | title = Acreage NASS | work = National Agricultural Statistics Board annual report | date = 30 June 2010 | access-date = 23 July 2010 }}</ref><ref name="USGMOCrops2009">{{cite web | url = http://www.gmo-compass.org/eng/agri_biotechnology/gmo_planting/506.usa_cultivation_gm_plants_2009.html | title = USA :Cultivation of GM Plants in 2009, Maize, soybean, cotton: 88 percent genetically modified | archive-url = https://web.archive.org/web/20120719060000/http://www.gmo-compass.org/eng/agri_biotechnology/gmo_planting/506.usa_cultivation_gm_plants_2009.html | archive-date = 19 July 2012 | work = GMO Compass | access-date = 25 July 2010 }}</ref> Genetically modified soybeans carried herbicide-tolerant traits only, but maize and cotton carried both herbicide tolerance and insect protection traits (the latter largely Bt protein).<ref>{{cite web | vauthors = Fernandez-Cornejo J | date = 5 July 2012 | url = http://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us/recent-trends-in-ge-adoption.aspx | title = Adoption of Genetically Engineered Crops in the U.S. – Recent Trends | work = USDA Economic Research Service | access-date = 29 September 2012 }}</ref> These constitute "input-traits" that are aimed to financially benefit the producers, but may have indirect environmental benefits and cost benefits to consumers. The Grocery Manufacturers of America estimated in 2003 that 70–75% of all processed foods in the U.S. contained a GM ingredient.<ref>{{cite journal | vauthors = Bren L | title = Genetic engineering: the future of foods? | journal = FDA Consumer | volume = 37 | issue = 6 | pages = 28–34 | date = November–December 2003 | pmid = 14986586 | url = http://permanent.access.gpo.gov/lps1609/www.fda.gov/fdac/features/2003/603_food.html | publisher = U.S. Food and Drug Administration }}</ref>

Europe grows relatively few genetically engineered crops<ref name="review">{{cite journal | vauthors = Lemaux PG | title = Genetically Engineered Plants and Foods: A Scientist's Analysis of the Issues (Part I) | journal = Annual Review of Plant Biology | volume = 59 | pages = 771–812 | date = 19 February 2008 | pmid = 18284373 | doi = 10.1146/annurev.arplant.58.032806.103840 }}</ref> with the exception of Spain, where one fifth of maize is genetically engineered,<ref>{{cite web | url = http://www.gmo-compass.org/eng/agri_biotechnology/gmo_planting/500.spain_bt_maize_prevails.html | title = Spain, Bt maize prevails | archive-url = https://web.archive.org/web/20121025222851/http://www.gmo-compass.org/eng/agri_biotechnology/gmo_planting/500.spain_bt_maize_prevails.html | archive-date = 25 October 2012 | work = GMO Compass | date = 31 March 2010 | access-date = 10 August 2010 }}</ref> and smaller amounts in five other countries.<ref>{{cite web | url = http://www.gmo-compass.org/eng/agri_biotechnology/gmo_planting/392.gm_maize_cultivation_europe_2009.html | title = GM plants in the EU in 2009 Field area for Bt maize decreases | archive-url = https://web.archive.org/web/20120713033027/http://www.gmo-compass.org/eng/agri_biotechnology/gmo_planting/392.gm_maize_cultivation_europe_2009.html | archive-date=13 July 2012 | work = GMO Compass | date = 29 March 2010 | access-date = 10 August 2010 }}</ref> The [[Social:European Union|EU]] had a 'de facto' ban on the approval of new GM crops, from 1999 until 2004.<ref name="EU ban on GMO illegal WTO rules">{{cite web|url=http://www.euractiv.com/en/trade/eu-gmo-ban-illegal-wto-rules/article-155197|title=EU GMO ban was illegal, WTO rules|date=12 May 2006|publisher=Euractiv.com|access-date=5 January 2010|archive-date=20 October 2017|archive-url=https://web.archive.org/web/20171020050240/http://www.euractiv.com/en/trade/eu-gmo-ban-illegal-wto-rules/article-155197|url-status=dead}}</ref><ref name="ICTSD: EU-US dispute over GM ban">{{cite web|url=http://ictsd.org/i/news/biores/9482/|title=GMO Update: US-EU Biotech Dispute; EU Regulations; Thailand|publisher=International Centre for Trade and Sustainable Development|access-date=5 January 2010|archive-date=4 March 2012|archive-url=https://web.archive.org/web/20120304052246/http://ictsd.org/i/news/biores/9482/|url-status=dead}}</ref> GM crops are now regulated by the EU.<ref name="Food Safety: from farm to fork">{{cite web|url=http://ec.europa.eu/food/food/biotechnology/index_en.htm|title=Genetically Modified Organisms |publisher = European Commission|website =Food Safety|date=17 October 2016 }}</ref> In 2015, genetically engineered crops are banned in 38 countries worldwide, 19 of them in Europe.<ref>{{cite web|url=http://sustainablepulse.com/2015/10/22/gm-crops-now-banned-in-36-countries-worldwide-sustainable-pulse-research/#.Vqkjw098Nbp|title=GM Crops Now Banned in 38 Countries Worldwide - Sustainable Pulse Research - Sustainable Pulse|date=22 October 2015}}</ref><ref>{{cite web|url=http://sustainablepulse.com/2015/10/04/gm-crop-bans-confirmed-in-19-eu-countries/#.Vqkkjk98Nbp|title=GM Crop Bans Confirmed in 19 EU Countries - Sustainable Pulse|date=4 October 2015}}</ref> Developing countries grew 54 percent of genetically engineered crops in 2013.<ref name="James2013" />

In recent years GM crops expanded rapidly in [[Finance:Developing country|developing countries]]. In 2013 approximately 18 million farmers grew 54% of worldwide GM crops in developing countries.<ref name="James2013" /> 2013's largest increase was in Brazil (403,000&nbsp;km<sup>2</sup> versus 368,000&nbsp;km<sup>2</sup> in 2012). GM cotton began growing in India in 2002, reaching 110,000&nbsp;km<sup>2</sup> in 2013.<ref name="James2013" />

According to the 2013 ISAAA brief: "a total of 36 countries (35 + EU-28) have granted regulatory approvals for biotech crops for food and/or feed use and for environmental release or planting since 1994&nbsp;... a total of 2,833 regulatory approvals involving 27 GM crops and 336 GM events (NB: an "event" is a specific genetic modification in a specific species) have been issued by authorities, of which 1,321 are for food use (direct use or processing), 918 for feed use (direct use or processing) and 599 for environmental release or planting. Japan has the largest number (198), followed by the U.S.A. (165, not including "stacked" events), Canada (146), Mexico (131), South Korea (103), Australia (93), New Zealand (83), European Union (71 including approvals that have expired or under renewal process), Philippines (68), Taiwan (65), Colombia (59), China (55) and South Africa (52). Maize has the largest number (130 events in 27 countries), followed by cotton (49 events in 22 countries), potato (31 events in 10 countries), canola (30 events in 12 countries) and soybean (27 events in 26 countries).<ref name="James2013" />

==Controversy==
{{Main|Philosophy:Genetically modified food controversies}}

Direct genetic engineering has been controversial since its introduction. Most, but not all of the controversies are over GM foods rather than crops per se. GM foods are the subject of protests, vandalism, referendums, legislation, court action<ref>{{cite journal | vauthors = Paull J | title = The threat of genetically modified organisms (GMOs) to organic agriculture: A case study update. | journal = Agriculture & Food | date = June 2015 | volume = 3 | pages = 56–63 | url = http://orgprints.org/29110/8/29110.pdf }}</ref> and scientific disputes. The controversies involve consumers, biotechnology companies, governmental regulators, non-governmental organizations and scientists.

Opponents have objected to GM crops on multiple grounds including environmental impacts, food safety, whether GM crops are needed to address food needs, whether they are sufficiently accessible to farmers in developing countries,<ref name="Azadi_2016" /> concerns over subjecting crops to [[Social:Intellectual property|intellectual property]] law, and on religious grounds.<ref name="PoW-1998">{{cite speech | author=HRH Charles, Prince of Wales | title=The Seeds of Disaster | date=8 June 1998 | url=http://www.princeofwales.gov.uk/speech/article-prince-wales-titled-seeds-disaster-daily-telegraph | access-date=13 October 2021 | website=Prince of Wales}}</ref> Secondary issues include labeling, the behavior of government regulators, the effects of pesticide use and pesticide tolerance.

A significant environmental concern about using genetically modified crops is possible cross-breeding with related crops, giving them advantages over naturally occurring varieties. One example is a glyphosate-resistant rice crop that crossbreeds with a weedy relative, giving the weed a competitive advantage. The transgenic hybrid had higher rates of photosynthesis, more shoots and flowers, and more seeds than the non-transgenic hybrids.<ref>{{cite journal| vauthors = Qiu J |s2cid=87415065|date=16 August 2013|title=Genetically modified crops pass benefits to weeds|url=https://www.nature.com/news/genetically-modified-crops-pass-benefits-to-weeds-1.13517|journal=Nature|language=en|doi=10.1038/nature.2013.13517|issn=1476-4687|doi-access=free}}</ref> This demonstrates the possibility of ecosystem damage by GM crop usage.

The role of [[Biology:Biopiracy|biopiracy]] in the development of GM crops is also potentially problematic, as developed countries have gotten economic gain by using the genetic resources of developing countries. In the twentieth century, the International Rice Research Institute catalogued the genomes of almost 80,000 varieties of rice from Asian farms, which has since been used to create new higher yielding varieties of rice. These new varieties create almost 655 million dollars of economic gain for Australia, USA, Canada, and New Zealand every year.<ref>{{Citation |last1=Satheeshkumar |first1=P. K. |title=Biopiracy |date=2017 |url=https://doi.org/10.1007/978-981-10-3573-9_9 |work=Bioresources and Bioprocess in Biotechnology: Volume 1: Status and Strategies for Exploration |pages=185–204 |editor-last=Abdulhameed |editor-first=Sabu |access-date=2023-10-20 |place=Singapore |publisher=Springer |language=en |doi=10.1007/978-981-10-3573-9_9 |isbn=978-981-10-3573-9 |last2=Narayanan |first2=Anoop |editor2-last=Pradeep |editor2-first=N.S. |editor3-last=Sugathan |editor3-first=Shiburaj}}</ref>

<!-- The following language and sources, per WP:GMORfC, must not be altered without achieving consensus-->There is a [[Philosophy:Scientific consensus|scientific consensus]]<ref name="Nicolia2013"/><ref name="FAO"/><ref name="Ronald2011"/><ref name="Also"/> that currently available food derived from GM crops poses no greater risk to human health than conventional food,<ref name="AAAS2012"/><ref name="ECom2010"/><ref name="AMA2001"/><ref name="LoC2015"/><ref name="NAS2016"/> but that each GM food needs to be tested on a case-by-case basis before introduction.<ref name="WHOFAQ"/><ref name="Haslberger2003"/><ref name="BMA2004"/> Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.<ref name="PEW2015"/><ref name="Marris2001"/><ref name="PABE"/><ref name="Scott2016"/> The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.<ref name="loc.gov"/><ref name="Bashshur"/><ref name="Sifferlin"/><ref name="Council on Foreign Relations"/><!--End of restricted section -->

No reports of ill effects from GM food have been documented in the human population.<ref name="AMA">{{cite web | publisher = American Medical Association | date = 2012 | url = http://www.ama-assn.org/resources/doc/csaph/a12-csaph2-bioengineeredfoods.pdf | title = Report 2 of the Council on Science and Public Health: Labeling of Bioengineered Foods | archive-url = https://web.archive.org/web/20120907023039/http://www.ama-assn.org/resources/doc/csaph/a12-csaph2-bioengineeredfoods.pdf | archive-date = 7 September 2012 }}</ref><ref name=NRC2004>{{cite book | author = United States Institute of Medicine and National Research Council | date = 2004 | title = Safety of Genetically Engineered Foods: Approaches to Assessing Unintended Health Effects. | publisher = National Academies Press | isbn = 9780309092098 | url = http://www.nap.edu/catalog.php?record_id=10977#toc }} See pp11ff on need for better standards and tools to evaluate GM food.</ref><ref name="Key">{{cite journal | vauthors = Key S, Ma JK, Drake PM | title = Genetically modified plants and human health | journal = Journal of the Royal Society of Medicine | volume = 101 | issue = 6 | pages = 290–8 | date = June 2008 | pmid = 18515776 | pmc = 2408621 | doi = 10.1258/jrsm.2008.070372 }}</ref> GM crop labeling is required in many countries, although the United States [[Organization:Food and Drug Administration|Food and Drug Administration]] does not, nor does it distinguish between approved GM and non-GM foods.<ref name=NYTImes2012>{{cite web | vauthors = Pollack A | work = The New York Times | url = https://www.nytimes.com/2012/05/22/business/kakha-bendukidze-holds-fate-of-gene-engineered-salmon.html?pagewanted=all | title = An Entrepreneur Bankrolls a Genetically Engineered Salmon | date = 21 May 2012 }}</ref> The United States enacted a law that requires labeling regulations to be issued by July 2018. It allows indirect disclosure such as with a phone number, bar code, or web site.<ref>{{cite web | url = https://www.congress.gov/bill/114th-congress/senate-bill/764/text | title = National bioengineered food disclosure standard | date = 29 July 2016 }}</ref>

Advocacy groups such as [[Organization:Center for Food Safety|Center for Food Safety]], [[Organization:Union of Concerned Scientists|Union of Concerned Scientists]], and Greenpeace claim that risks related to GM food have not been adequately examined and managed, that GM crops are not sufficiently tested and should be labelled, and that regulatory authorities and scientific bodies are too closely tied to industry. {{citation needed|date=June 2017}} Some studies have claimed that genetically modified crops can cause harm;<ref>{{cite journal | vauthors = Domingo JL, Giné Bordonaba J | title = A literature review on the safety assessment of genetically modified plants | journal = Environment International | volume = 37 | issue = 4 | pages = 734–42 | date = May 2011 | pmid = 21296423 | doi = 10.1016/j.envint.2011.01.003 | url = http://gaiapresse.ca/images/nouvelles/28563.pdf }}</ref><ref>{{cite journal|url=http://www.tufts.edu/~skrimsky/PDF/Illusory%20Consensus%20GMOs.PDF|title=An Illusory Consensus behind GMO Health Assessment| vauthors = Krimsky S |s2cid=40855100|journal=Science, Technology, & Human Values|pages=883–914|doi=10.1177/0162243915598381|date=2015|volume=40|issue=6|access-date=9 February 2016|archive-url=https://web.archive.org/web/20160207171524/http://www.tufts.edu/~skrimsky/PDF/Illusory%20Consensus%20GMOs.PDF|archive-date=7 February 2016|url-status=dead}}</ref> a 2016 review that reanalyzed the data from six of these studies found that their statistical methodologies were flawed and did not demonstrate harm, and said that conclusions about GM crop safety should be drawn from "the totality of the evidence&nbsp;... instead of far-fetched evidence from single studies".<ref name=Panchin2016>{{cite journal | vauthors = Panchin AY, Tuzhikov AI | s2cid = 11786594 | title = Published GMO studies find no evidence of harm when corrected for multiple comparisons | journal = Critical Reviews in Biotechnology | volume = 37 | issue = 2 | pages = 213–217 | date = March 2017 | pmid = 26767435 | doi = 10.3109/07388551.2015.1130684 }}</ref>

== See also ==

* [[Earth:Food security|Food security]]

==Notes==
{{Reflist|group="N"}}

== References ==
{{Reflist|refs=
<ref name="Nicolia2013">{{cite journal | vauthors = Nicolia A, Manzo A, Veronesi F, Rosellini D | s2cid = 9836802 | title = An overview of the last 10 years of genetically engineered crop safety research | journal = Critical Reviews in Biotechnology | volume = 34 | issue = 1 | pages = 77–88 | date = March 2014 | pmid = 24041244 | doi = 10.3109/07388551.2013.823595 | url = https://www.pps.net/cms/lib/OR01913224/Centricity/Domain/3337/peer%20reviewed%20meta%20study%20on%20GMOs%20copy.pdf | quote = We have reviewed the scientific literature on GE crop safety for the last 10 years that catches the scientific consensus matured since GE plants became widely cultivated worldwide, and we can conclude that the scientific research conducted so far has not detected any significant hazard directly connected with the use of GM crops.<br /><br/>The literature about Biodiversity and the GE food/feed consumption has sometimes resulted in animated debate regarding the suitability of the experimental designs, the choice of the statistical methods or the public accessibility of data. Such debate, even if positive and part of the natural process of review by the scientific community, has frequently been distorted by the media and often used politically and inappropriately in anti-GE crops campaigns. }}</ref>
<ref name="FAO">{{cite web|url=http://www.fao.org/docrep/006/Y5160E/y5160e10.htm#P3_1651The|title=State of Food and Agriculture 2003–2004. Agricultural Biotechnology: Meeting the Needs of the Poor. Health and environmental impacts of transgenic crops|publisher=Food and Agriculture Organization of the United Nations|access-date=30 August 2019|quote=Currently available transgenic crops and foods derived from them have been judged safe to eat and the methods used to test their safety have been deemed appropriate. These conclusions represent the consensus of the scientific evidence surveyed by the ICSU (2003) and they are consistent with the views of the World Health Organization (WHO, 2002). These foods have been assessed for increased risks to human health by several national regulatory authorities (inter alia, Argentina, Brazil, Canada, China, the United Kingdom and the United States) using their national food safety procedures (ICSU). To date no verifiable untoward toxic or nutritionally deleterious effects resulting from the consumption of foods derived from genetically modified crops have been discovered anywhere in the world (GM Science Review Panel). Many millions of people have consumed foods derived from GM plants - mainly maize, soybean and oilseed rape - without any observed adverse effects (ICSU).}}</ref>
<ref name="Ronald2011">{{cite journal | vauthors = Ronald P | title = Plant genetics, sustainable agriculture and global food security | journal = Genetics | volume = 188 | issue = 1 | pages = 11–20 | date = May 2011 | pmid = 21546547 | pmc = 3120150 | doi = 10.1534/genetics.111.128553 | quote = "There is broad scientific consensus that genetically engineered crops currently on the market are safe to eat. After 14 years of cultivation and a cumulative total of 2 billion acres planted, no adverse health or environmental effects have resulted from commercialization of genetically engineered crops (Board on Agriculture and Natural Resources, Committee on Environmental Impacts Associated with Commercialization of Transgenic Plants, National Research Council and Division on Earth and Life Studies 2002). Both the U.S. National Research Council and the Joint Research Centre (the European Union's scientific and technical research laboratory and an integral part of the European Commission) have concluded that there is a comprehensive body of knowledge that adequately addresses the food safety issue of genetically engineered crops (Committee on Identifying and Assessing Unintended Effects of Genetically Engineered Foods on Human Health and National Research Council 2004; European Commission Joint Research Centre 2008). These and other recent reports conclude that the processes of genetic engineering and conventional breeding are no different in terms of unintended consequences to human health and the environment (European Commission Directorate-General for Research and Innovation 2010)." }}</ref>
<ref name="Also"><p>But see also:</p><p>{{cite journal | vauthors = Domingo JL, Giné Bordonaba J | title = A literature review on the safety assessment of genetically modified plants | journal = Environment International | volume = 37 | issue = 4 | pages = 734–42 | date = May 2011 | pmid = 21296423 | doi = 10.1016/j.envint.2011.01.003 | url = http://gaiapresse.ca/images/nouvelles/28563.pdf | quote = In spite of this, the number of studies specifically focused on safety assessment of GM plants is still limited. However, it is important to remark that for the first time, a certain equilibrium in the number of research groups suggesting, on the basis of their studies, that a number of varieties of GM products (mainly maize and soybeans) are as safe and nutritious as the respective conventional non-GM plant, and those raising still serious concerns, was observed. Moreover, it is worth mentioning that most of the studies demonstrating that GM foods are as nutritional and safe as those obtained by conventional breeding, have been performed by biotechnology companies or associates, which are also responsible of commercializing these GM plants. Anyhow, this represents a notable advance in comparison with the lack of studies published in recent years in scientific journals by those companies. }}</p><p>{{cite journal|title=An Illusory Consensus behind GMO Health Assessment| vauthors = Krimsky S |s2cid=40855100|journal=Science, Technology, & Human Values|volume=40|issue=6|pages=883–914|doi=10.1177/0162243915598381|date=2015|quote=I began this article with the testimonials from respected scientists that there is literally no scientific controversy over the health effects of GMOs. My investigation into the scientific literature tells another story.}}</p><p>And contrast:</p><p>{{cite journal | vauthors = Panchin AY, Tuzhikov AI | s2cid = 11786594 | title = Published GMO studies find no evidence of harm when corrected for multiple comparisons | journal = Critical Reviews in Biotechnology | volume = 37 | issue = 2 | pages = 213–217 | date = March 2017 | pmid = 26767435 | doi = 10.3109/07388551.2015.1130684 | quote = Here, we show that a number of articles some of which have strongly and negatively influenced the public opinion on GM crops and even provoked political actions, such as GMO embargo, share common flaws in the statistical evaluation of the data. Having accounted for these flaws, we conclude that the data presented in these articles does not provide any substantial evidence of GMO harm. <br /><br/> The presented articles suggesting possible harm of GMOs received high public attention. However, despite their claims, they actually weaken the evidence for the harm and lack of substantial equivalency of studied GMOs. We emphasize that with over 1783 published articles on GMOs over the last 10 years it is expected that some of them should have reported undesired differences between GMOs and conventional crops even if no such differences exist in reality. }}</p><p>and</p>{{cite journal | vauthors = Yang YT, Chen B | title = Governing GMOs in the USA: science, law and public health | journal = Journal of the Science of Food and Agriculture | volume = 96 | issue = 6 | pages = 1851–5 | date = April 2016 | pmid = 26536836 | doi = 10.1002/jsfa.7523 | bibcode = 2016JSFA...96.1851Y | quote = It is therefore not surprising that efforts to require labeling and to ban GMOs have been a growing political issue in the USA ''(citing Domingo and Bordonaba, 2011)''. Overall, a broad scientific consensus holds that currently marketed GM food poses no greater risk than conventional food&nbsp;... Major national and international science and medical associations have stated that no adverse human health effects related to GMO food have been reported or substantiated in peer-reviewed literature to date.<br /><br/>Despite various concerns, today, the American Association for the Advancement of Science, the World Health Organization, and many independent international science organizations agree that GMOs are just as safe as other foods. Compared with conventional breeding techniques, genetic engineering is far more precise and, in most cases, less likely to create an unexpected outcome. }}</ref>
<ref name="AAAS2012">{{cite web|url=http://www.aaas.org/sites/default/files/AAAS_GM_statement.pdf|title=Statement by the AAAS Board of Directors On Labeling of Genetically Modified Foods|publisher=American Association for the Advancement of Science|date=20 October 2012|access-date=30 August 2019|quote="The EU, for example, has invested more than €300 million in research on the biosafety of GMOs. Its recent report states: "The main conclusion to be drawn from the efforts of more than 130 research projects, covering a period of more than 25 years of research and involving more than 500 independent research groups, is that biotechnology, and in particular GMOs, are not per se more risky than e.g. conventional plant breeding technologies." The World Health Organization, the American Medical Association, the U.S. National Academy of Sciences, the British Royal Society, and every other respected organization that has examined the evidence has come to the same conclusion: consuming foods containing ingredients derived from GM crops is no riskier than consuming the same foods containing ingredients from crop plants modified by conventional plant improvement techniques."}}<br /><br/>{{cite web|url=https://www.aaas.org/sites/default/files/AAAS_GM_statement.pdf|title=AAAS Board of Directors: Legally Mandating GM Food Labels Could "Mislead and Falsely Alarm Consumers"| vauthors = Pinholste G |publisher=American Association for the Advancement of Science|date=25 October 2012|access-date=30 August 2019}}</ref>
<ref name="ECom2010">{{cite book|url=http://ec.europa.eu/research/biosociety/pdf/a_decade_of_eu-funded_gmo_research.pdf|title=A decade of EU-funded GMO research (2001–2010)|publisher=Directorate-General for Research and Innovation. Biotechnologies, Agriculture, Food. European Commission, European Union.|doi=10.2777/97784|isbn=978-92-79-16344-9|access-date=30 August 2019|date=2010|author1=European Commission. Directorate-General for Research}}</ref>
<ref name="AMA2001">{{Cite web|url=https://www.isaaa.org/kc/Publications/htm/articles/Position/ama.htm|title=AMA Report on Genetically Modified Crops and Foods (online summary)|publisher=American Medical Association|date=January 2001|access-date=30 August 2019|quote="A report issued by the scientific council of the American Medical Association (AMA) says that no long-term health effects have been detected from the use of transgenic crops and genetically modified foods, and that these foods are substantially equivalent to their conventional counterparts." "Crops and foods produced using recombinant DNA techniques have been available for fewer than 10 years and no long-term effects have been detected to date. These foods are substantially equivalent to their conventional counterparts."}}<br /><br />{{Cite web|url=http://www.ama-assn.org/resources/doc/csaph/a12-csaph2-bioengineeredfoods.pdf|archive-url=https://web.archive.org/web/20120907023039/http://www.ama-assn.org/resources/doc/csaph/a12-csaph2-bioengineeredfoods.pdf|url-status=dead|title=Report 2 of the Council On Science and Public Health (A-12): Labeling of Bioengineered Foods|publisher=American Medical Association|date=2012|access-date=30 August 2019|quote=Bioengineered foods have been consumed for close to 20 years, and during that time, no overt consequences on human health have been reported and/or substantiated in the peer-reviewed literature.|archive-date=7 September 2012}}</ref>
<ref name="LoC2015">{{cite web|url=http://www.loc.gov/law/help/restrictions-on-gmos/usa.php#Opinion|title=Restrictions on Genetically Modified Organisms: United States. Public and Scholarly Opinion|publisher=Library of Congress|date=30 June 2015|access-date=30 August 2019|quote="Several scientific organizations in the US have issued studies or statements regarding the safety of GMOs indicating that there is no evidence that GMOs present unique safety risks compared to conventionally bred products. These include the National Research Council, the American Association for the Advancement of Science, and the American Medical Association. Groups in the US opposed to GMOs include some environmental organizations, organic farming organizations, and consumer organizations. A substantial number of legal academics have criticized the US's approach to regulating GMOs."}}</ref>
<ref name="NAS2016">{{cite book|url=http://www.nap.edu/read/23395/chapter/7#149|title=Genetically Engineered Crops: Experiences and Prospects|publisher=The National Academies of Sciences, Engineering, and Medicine (US)|page=149|date=2016|access-date=30 August 2019|doi=10.17226/23395|pmid=28230933|quote="''Overall finding on purported adverse effects on human health of foods derived from GE crops:'' On the basis of detailed examination of comparisons of currently commercialized GE with non-GE foods in compositional analysis, acute and chronic animal toxicity tests, long-term data on health of livestock fed GE foods, and human epidemiological data, the committee found no differences that implicate a higher risk to human health from GE foods than from their non-GE counterparts."|isbn=978-0-309-43738-7|last1=National Academies Of Sciences |author2=Division on Earth Life Studies Engineering |author3=Board on Agriculture Natural Resources|author4=Committee on Genetically Engineered Crops: Past Experience Future Prospects}}</ref> 
<ref name="WHOFAQ">{{cite web|url=https://www.who.int/foodsafety/areas_work/food-technology/faq-genetically-modified-food/en/|title=Frequently asked questions on genetically modified foods|publisher=World Health Organization|access-date=30 August 2019|quote=Different GM organisms include different genes inserted in different ways. This means that individual GM foods and their safety should be assessed on a case-by-case basis and that it is not possible to make general statements on the safety of all GM foods.<br /><br/>GM foods currently available on the international market have passed safety assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general population in the countries where they have been approved. Continuous application of safety assessments based on the Codex Alimentarius principles and, where appropriate, adequate post market monitoring, should form the basis for ensuring the safety of GM foods.}}</ref>
<ref name="Haslberger2003">{{cite journal | vauthors = Haslberger AG | s2cid = 2533628 | title = Codex guidelines for GM foods include the analysis of unintended effects | journal = Nature Biotechnology | volume = 21 | issue = 7 | pages = 739–41 | date = July 2003 | pmid = 12833088 | doi = 10.1038/nbt0703-739 | quote = These principles dictate a case-by-case premarket assessment that includes an evaluation of both direct and unintended effects. }}</ref>
<ref name="BMA2004">Some medical organizations, including the British Medical Association, advocate further caution based upon the [[Precautionary principle|precautionary principle]]:<br /><br/>{{cite web|url=http://www.argenbio.org/adc/uploads/pdf/bma.pdf|title=Genetically modified foods and health: a second interim statement|publisher=British Medical Association|date=March 2004|access-date=30 August 2019|quote=In our view, the potential for GM foods to cause harmful health effects is very small and many of the concerns expressed apply with equal vigour to conventionally derived foods. However, safety concerns cannot, as yet, be dismissed completely on the basis of information currently available.<br /><br/>When seeking to optimise the balance between benefits and risks, it is prudent to err on the side of caution and, above all, learn from accumulating knowledge and experience. Any new technology such as genetic modification must be examined for possible benefits and risks to human health and the environment. As with all novel foods, safety assessments in relation to GM foods must be made on a case-by-case basis.<br /><br/>Members of the GM jury project were briefed on various aspects of genetic modification by a diverse group of acknowledged experts in the relevant subjects. The GM jury reached the conclusion that the sale of GM foods currently available should be halted and the moratorium on commercial growth of GM crops should be continued. These conclusions were based on the precautionary principle and lack of evidence of any benefit. The Jury expressed concern over the impact of GM crops on farming, the environment, food safety and other potential health effects.<br /><br/>The Royal Society review (2002) concluded that the risks to human health associated with the use of specific viral DNA sequences in GM plants are negligible, and while calling for caution in the introduction of potential allergens into food crops, stressed the absence of evidence that commercially available GM foods cause clinical allergic manifestations. The BMA shares the view that there is no robust evidence to prove that GM foods are unsafe but we endorse the call for further research and surveillance to provide convincing evidence of safety and benefit.}}</ref>
<ref name="PEW2015">{{cite web|url=http://www.pewinternet.org/2015/01/29/public-and-scientists-views-on-science-and-society/|title=Public and Scientists' Views on Science and Society| vauthors = Funk C, Rainie L |publisher=Pew Research Center|date=29 January 2015|access-date=30 August 2019|quote=The largest differences between the public and the AAAS scientists are found in beliefs about the safety of eating genetically modified (GM) foods. Nearly nine-in-ten (88%) scientists say it is generally safe to eat GM foods compared with 37% of the general public, a difference of 51 percentage points.}}</ref>
<ref name="Marris2001">{{cite journal | vauthors = Marris C | title = Public views on GMOs: deconstructing the myths. Stakeholders in the GMO debate often describe public opinion as irrational. But do they really understand the public? | journal = EMBO Reports | volume = 2 | issue = 7 | pages = 545–8 | date = July 2001 | pmid = 11463731 | pmc = 1083956 | doi = 10.1093/embo-reports/kve142 }}</ref>
<ref name="PABE">{{cite web|url=http://csec.lancs.ac.uk/archive/pabe/docs/pabe_finalreport.doc|title=Public Perceptions of Agricultural Biotechnologies in Europe|date=December 2001|author=Final Report of the PABE research project|publisher=Commission of European Communities|archive-url=https://web.archive.org/web/20170525042822/http://csec.lancs.ac.uk/archive/pabe/docs/pabe_finalreport.doc |archive-date=25 May 2017|access-date=30 August 2019}}</ref>
<ref name="Scott2016">{{cite journal | vauthors = Scott SE, Inbar Y, Rozin P | s2cid = 261060 | title = Evidence for Absolute Moral Opposition to Genetically Modified Food in the United States | journal = Perspectives on Psychological Science | volume = 11 | issue = 3 | pages = 315–24 | date = May 2016 | pmid = 27217243 | doi = 10.1177/1745691615621275 | url = http://yoelinbar.net/papers/gmo_absolute.pdf }}</ref>
<ref name="loc.gov">{{cite web|url=http://www.loc.gov/law/help/restrictions-on-gmos/|title=Restrictions on Genetically Modified Organisms|publisher=Library of Congress|date=9 June 2015|access-date=30 August 2019}}</ref>
<ref name="Bashshur">{{cite web|url=http://www.americanbar.org/content/newsletter/publications/aba_health_esource_home/aba_health_law_esource_1302_bashshur.html|title=FDA and Regulation of GMOs|first=Ramona|last=Bashshur | name-list-style = vanc |publisher=American Bar Association|date=February 2013|archive-url=https://web.archive.org/web/20180621044554/https://www.americanbar.org/content/newsletter/publications/aba_health_esource_home/aba_health_law_esource_1302_bashshur.html|archive-date=21 June 2018|access-date=30 August 2019}}</ref>
<ref name="Sifferlin">{{cite magazine|url=http://time.com/4060476/eu-gmo-crops-european-union-opt-out/|title=Over Half of E.U. Countries Are Opting Out of GMOs|first=Alexandra|last=Sifferlin | name-list-style = vanc |magazine=Time|date=3 October 2015|access-date=30 August 2019}}</ref>
<ref name="Council on Foreign Relations">{{cite web|url=http://www.cfr.org/agricultural-policy/regulation-gmos-europe-united-states-case-study-contemporary-european-regulatory-politics/p8688|title=The Regulation of GMOs in Europe and the United States: A Case-Study of Contemporary European Regulatory Politics |first1=Diahanna |last1=Lynch |first2=David |last2=Vogel | name-list-style = vanc |publisher=Council on Foreign Relations|date=5 April 2001|access-date=30 August 2019|archive-url=https://web.archive.org/web/20160929200540/http://www.cfr.org/agricultural-policy/regulation-gmos-europe-united-states-case-study-contemporary-european-regulatory-politics/p8688|archive-date=29 September 2016|url-status=dead}}</ref>
}}

== External links ==
{{Library resources box
 |onlinebooks=no
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}}
* {{cite web | url = http://ec.europa.eu/food/dyna/gm_register/index_en.cfm | title = EU Register of authorised GM crops }}
* {{cite web | url = http://www.accessdata.fda.gov/scripts/fdcc/?set=Biocon | title =  Biotechnology Consultations on Food from GE Plant Varieties }}
* {{cite web | url = http://www.epa.gov/pesticides/biopesticides/pips/pip_list.htm | title =  Current & Previously Registered Section 3 PIP Registrations }}

{{Genetic engineering}}

{{DEFAULTSORT:Genetically Modified Crops}}
[[Category:Genetic engineering]]

{{Sourceattribution|Genetically modified crops}}