Religion:Protoplast
Protoplast (from grc πρωτόπλαστος (prōtóplastos) 'first-formed'), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall.[1][2] Protoplasts can be generated by stripping the cell wall from plant,[3] bacterial,[4][5] or fungal cells[5][6] by mechanical, chemical or enzymatic means.
Protoplasts differ from spheroplasts in that their cell wall has been completely removed.[4][5] Spheroplasts retain part of their cell wall.[7] In the case of Gram-negative bacterial spheroplasts, for example, the peptidoglycan component of the cell wall has been removed but the outer membrane component has not.[4][5]
Enzymes for the preparation of protoplasts
Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes:
| Type of cell | Enzyme |
|---|---|
| Plant cells | Cellulase, pectinase, xylanase[3] |
| Gram-positive bacteria | Lysozyme, N,O-diacetylmuramidase, lysostaphin[4] |
| Fungal cells | Chitinase[6] |
Uses for protoplasts
Protoplasts can be used to study membrane biology, including the uptake of macromolecules and viruses . These are also used in somaclonal variation.
Protoplasts are widely used for DNA transformation (for making genetically modified organisms), since the cell wall would otherwise block the passage of DNA into the cell.[3] In the case of plant cells, protoplasts may be regenerated into whole plants first by growing into a group of plant cells that develops into a callus and then by regeneration of shoots (caulogenesis) from the callus using plant tissue culture methods.[8] Growth of protoplasts into callus and regeneration of shoots requires the proper balance of plant growth regulators in the tissue culture medium that must be customized for each species of plant.[9][10] Unlike protoplasts from vascular plants, protoplasts from mosses, such as Physcomitrella patens, do not need phytohormones for regeneration, nor do they form a callus during regeneration. Instead, they regenerate directly into the filamentous protonema, mimicking a germinating moss spore.[11]
Protoplasts may also be used for plant breeding, using a technique called protoplast fusion. Protoplasts from different species are induced to fuse by using an electric field or a solution of polyethylene glycol.[12] This technique may be used to generate somatic hybrids in tissue culture.
See also
References
- ↑ Das Protoplasma als Träger der pflanzlichen und thierischen Lebensverrichtungen für Laien und Fachgenossen.. Heidelberg: Selbstverlag. 1880. https://archive.org/details/DasProtoplasma.
- ↑ An introduction to cytology.. New York: McGraw-Hill book Company, Incorporated. 1921. p. 24. https://archive.org/details/introductiontocy032473mbp.
- ↑ 3.0 3.1 3.2 "Plant protoplasts: status and biotechnological perspectives". Biotechnology Advances 23 (2): 131–171. March 2005. doi:10.1016/j.biotechadv.2004.09.008. PMID 15694124.
- ↑ 4.0 4.1 4.2 4.3 "Morphological and ultrastructural changes in bacterial cells as an indicator of antibacterial mechanism of action". Cellular and Molecular Life Sciences 73 (23): 4471–4492. December 2016. doi:10.1007/s00018-016-2302-2. PMID 27392605.
- ↑ 5.0 5.1 5.2 5.3 "Protoplasts and spheroplasts". Encyclopedia.com. 2016. https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/protoplasts-and-spheroplasts.
- ↑ 6.0 6.1 "Biotechnological aspects of chitinolytic enzymes: a review". Applied Microbiology and Biotechnology 71 (6): 773–782. August 2006. doi:10.1007/s00253-005-0183-7. PMID 16249876.
- ↑ "Definition of spheroplast". Merriam-Webster. 2019. https://www.merriam-webster.com/dictionary/spheroplast.
- ↑ "History of plant tissue culture". Molecular Biotechnology 37 (2): 169–180. October 2007. doi:10.1007/s12033-007-0031-3. PMID 17914178.
- ↑ "Establishment of an Efficient Protoplast Regeneration and Transfection Protocol for Field Cress (Lepidium campestre)". Frontiers in Genome Editing 3. 16 November 2021. doi:10.3389/fgeed.2021.757540. PMID 34870274.
- ↑ "Efficient Protoplast Regeneration Protocol and CRISPR/Cas9-Mediated Editing of Glucosinolate Transporter (GTR) Genes in Rapeseed (Brassica napus L.)". Frontiers in Plant Science 12. 2021-07-07. doi:10.3389/fpls.2021.680859. PMID 34305978. Bibcode: 2021FrPS...1280859L.
- ↑ Bhatla SC, Kiessling J, Reski R (2002): Observation of polarity induction by cytochemical localization of phenylalkylamine-binding receptors in regenerating protoplasts of the moss Physcomitrella patens. Protoplasma 219, 99–105.
- ↑ "Uptake, integration, expression and genetic transmission of a selectable chimaeric gene by plant protoplasts.". Molecular and General Genetics MGG 199 (2): 161–168. May 1985. doi:10.1007/BF00330254.
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