Question

“Specific Bt Toxin gene is incorporated into cotton plant so as to control infestation of Bollworm”. Mention the organism from which the gene was isolated and explain its mode of action.

Answer 1

Specific Bt toxin genes isolated from Bacillus thuringiensis is incorporated into cotton is coded by the genes cryIAc and cryIIAb that control the cotton bollworms

•  Bacillus forms protein crystals that contain a toxic insecticidal protein.

•  once an insect ingest the inactive toxin, it is converted into an active form

•  The toxin in the form of crystals gets solubilised due to alkaline pH in the gut

•  The activated toxin binds to the surface of gut epithelial cells and perforate the walls causing the death of insect larva