Protoplast

entire biological cell, excluding the cell wall

Protoplast in modern biology, is what is left of a cell when the cell wall is dissolved. That leaves the cell's nucleus and the surrounding protoplasmic materials.

Protoplasts of cells from a petunia's leaf
Protoplasts of Physcomitrella patens

Definition: a protoplast is a plant, bacterial or fungal cell that had its cell wall completely or partially removed using either mechanical or enzymatic means.

Because cell walls are made differently in the different kingdoms, different enzymes are used to remove them.

Enzymes for the preparation of protoplastsEdit

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
Gram-positive bacteria Lysozyme (+EDTA)
Fungal cells Chitinase

The reason for removing the cell walls is to allow many different experimental techniques to be used.

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.[1] In the case of plant cells, protoplasts can be regenerated into whole plants.[2]

ReferencesEdit

  1. Davey M.R. et al 2005 (2005). "Plant protoplasts: status and biotechnological perspectives". Biotechnol. Adv. 23 (2): 131–71. doi:10.1016/j.biotechadv.2004.09.008. PMID 15694124.{{cite journal}}: CS1 maint: uses authors parameter (link)
  2. Thorpe T.A. 2007 (2007). "History of plant tissue culture". Mol. Biotechnol. 37 (2): 169–80. doi:10.1007/s12033-007-0031-3. PMID 17914178. S2CID 25641573.