Protoplast

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:

During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmotic stress. This means cell wall digestion and protoplast storage must be done in an isotonic solution to prevent rupture of the plasma membrane.{{Citation needed|date=August 2023}}

File:Protoplast fusion.jpg

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.{{cite journal | vauthors = Davey MR, Anthony P, Power JB, Lowe KC | title = Plant protoplasts: status and biotechnological perspectives | journal = Biotechnology Advances | volume = 23 | issue = 2 | pages = 131–171 | date = March 2005 | pmid = 15694124 | doi = 10.1016/j.biotechadv.2004.09.008 }} 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.{{cite journal | vauthors = Thorpe TA | title = History of plant tissue culture | journal = Molecular Biotechnology | volume = 37 | issue = 2 | pages = 169–180 | date = October 2007 | pmid = 17914178 | doi = 10.1007/s12033-007-0031-3 | s2cid = 25641573 }} 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.{{cite journal | vauthors = Sandgrind S, Li X, Ivarson E, Ahlman A, Zhu LH | title = Establishment of an Efficient Protoplast Regeneration and Transfection Protocol for Field Cress (Lepidium campestre) | journal = Frontiers in Genome Editing | volume = 3 | pages = 757540 | date = 16 November 2021 | pmid = 34870274 | pmc = 8635052 | doi = 10.3389/fgeed.2021.757540 | doi-access = free }}{{cite journal | vauthors = Li X, Sandgrind S, Moss O, Guan R, Ivarson E, Wang ES, Kanagarajan S, Zhu LH | title = Efficient Protoplast Regeneration Protocol and CRISPR/Cas9-Mediated Editing of Glucosinolate Transporter (GTR) Genes in Rapeseed (Brassica napus L.) | journal = Frontiers in Plant Science | volume = 12 | pages = 680859 | date = 2021-07-07 | pmid = 34305978 | pmc = 8294089 | doi = 10.3389/fpls.2021.680859 | doi-access = free | bibcode = 2021FrPS...1280859L }} 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.Bhatla SC, Kiessling J, Reski R (2002): [https://archive.today/20130203001100/http://www.springerlink.com/content/m747f7xfu9dxyprw/?p=2747894a7a9849a09e60b0e49f51afdc&pi=3 Observation of polarity induction by cytochemical localization of phenylalkylamine-binding receptors in regenerating protoplasts of the moss Physcomitrella patens]. Protoplasma 219, 99–105.

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.{{cite journal | vauthors = Hain R, Stabel P, Czernilofsky AP, Steinbiß HH, Herrera-Estrella L, Schell J | title = Uptake, integration, expression and genetic transmission of a selectable chimaeric gene by plant protoplasts. | journal = Molecular and General Genetics MGG | date = May 1985 | volume = 199 | issue = 2 | pages = 161–168 | doi = 10.1007/BF00330254 }} This technique may be used to generate somatic hybrids in tissue culture.{{Citation needed|date=August 2023}}

Additionally, protoplasts of plants expressing fluorescent proteins in certain cells may be used for Fluorescence Activated Cell Sorting (FACS), where only cells fluorescing a selected wavelength are retained. Among other things, this technique is used to isolate specific cell types (e.g., guard cells from leaves, pericycle cells from roots) for further investigations, such as transcriptomics.{{Citation needed|date=August 2023}}

• Bacterial morphological plasticity
• L-form bacteria
• Spheroplasts

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Category:Cell biology

Category:Membrane biology

Category:Molecular biology

Category:Plant physiology

Category:Plant reproduction