What Do We Mean by Protoplast

What do we mean by protoplast?

A protoplast is a cell of the plant that has its wall removed. The walls of the cell can be removed by chemical or mechanical methods. 

The term Protoplast is an Ancient Greek biological term coined in 1880 by Hanstein to refer to an entire cell except for the walls of the cell. 

Enzymes Used for the Preparation of Protoplasts

The walls of a cell are made from a number of polysaccharides. Protoplasts can be made by removing the polysaccharides using enzymes. 

Different enzymes are used for different types of cells- 

• Plant cells- to remove polysaccharides from the plant cells, cellulase, pectinase, and xylanase enzymes are used
• Gram-positive bacteria- Lysozyme, lysostaphin, and enzymes are used for removing the cell walls from gram-positive bacteria
• Fungal cells- Chitinase enzyme is used

After the digestion of the cell wall, the Protoplast is exposed to osmotic stress. To protect the Protoplast from getting ruptured, the cell wall digestion and the storage of the Protoplast must be done in an isotonic solution. 

Benefits of Protoplast

• Membrane biology can be studied through Protoplasts. Viruses can be detected and macromolecules can be studied closely
• Protoplasts are used for making DNA modifications and transforming organisms genetically. The cell wall would otherwise block the entry of DNA into the cell
• Plant breeding can also be done using Protoplasts. An electric field or a solution of polyethylene glycol can be used to fuse different species of Protoplast. This is known as protoplast fusion. Semantic hybrids in the tissue culture are produced by using this technique
• Protoplasts are also used for fluorescence-activated cell sorting where certain plant cells are separated to carry out investigations
• The physiology of a cell can be studied with the help of a protoplast. Cell surface interactions with toxins and pathogens can also be discovered