Protoplast fusion

Proptoplast fusion 

Protoplast: this is a component of plant cell which lacks cell wall .Hanstein coined the term ”PROTOPLAST”. Protoplast isolation is commonly used termed in agricultural biotechnology for growing plants in artificial environment .Protoplast are isolated by two techniques:

ü Mechanical 

ü Enzymatic methods 

Protoplast fusion involves mixing of two different protoplast containing different genomes through either by spontaneous or induced fusion methods .

Mentioned below are the few techniques which are mostly used in protoplast fusions :

ü Spontaneous fusion

ü Induced fusion method 

ü Treatment with Sodium nitrate 

ü Calcium ions at  high pH

ü Polyethylene glycol methods

ü Electro fusion

Mechanism of fusion:

There are three  main phase of fusion :

Agglutination:two or mor protoplast are brought in close proximity by means of PEG, high Ph, high Ca ions ,etc.

Plasma membrane fusion at localised sites:

At point of adhesion (agglutination) membranes of different protoplast gets fused ,the use of high pH is done to neutralise the common charge in plasma membranes and allow the protoplasm to fuse well.

Formation of  heterokaryon: cytoplasmic  bridges are formed due to charges repulsion in protoplast fusion ,thus fused protoplast are rounded off and forms spherical heterokaryon or homokaryon.