Question

The fusogen used during the protoplast fusion is known as
A. PEG
B. Magnesium chloride
C. Calcium phosphate
D. All of the above

Answer 1

Protoplast is defined as a plant, animal, or bacterial cells whose cell wall has been completely or partially removed by either physical or chemical methods. Thus, they are that unit of the cell containing the nucleus and the surrounding protoplasm.

Complete answer:
Protoplasmic fusion can be either interspecific or intraspecific. Different factors called the fusogens are used to induce fusion. The method of induced fusion is not preferred due to its low frequency. Various chemicals like calcium ion and polyethylene glycol (PEG) are widely used in this induced method of protoplasmic fusion.
In the case of induced fusion usingions, the protoplast is centrifuged in a fusion mixture containing mannitol at a very high pH offorminutes. These tubes are then transferred into a water bath at 37 degrees Celsius for 40minutes. As a result of this treatment,fusion can be achieved.
PEG has been commonly used for fusion of protoplast in various crops due to its high frequency of fusion and low cytotoxicity. Electric fusion is another method used for the same. In this, the protoplasts are placed in a very small cultural vessel containing electrodes. On applying a potential difference, the protoplast lines up near the electrodes which fuses with application of an electric shock.
Therefore, fusogens including PEG, Magnesium chloride or calcium phosphate can be used to induce fusion of the protoplast.

The correct answer is option D, which states “all of the above”.

Note: Protoplasm can be obtained from any part of the plant like root, stem, pollen mother cell, and callus. The protoplast can be isolated by cutting the cell wall of a cell using a fine knife or by using various polysaccharide-degrading enzymes that degrade the cell wall, releasing the protoplast further.