“Specific Bt Toxin gene is incorporated into the cotton plant so as to control the infestation of Bollworm”. Mention the organism from which the gene was isolated and explain its mode of action.
Specific Bt toxin genes isolated from Bacillus Thuringiensis are incorporated into cotton. Cry I AC and Cry II AC control the bollworm. Bt gene forms protein crystals that contain a toxin insecticidal protein. It is in an inactive state. The inactive toxin is converted into active form due to the alkaline pH of the gut which solubilizes the crystal. Activated Bt-toxin binds to the surface of midgut epithelial cells and creates pores that cause cell swelling and lysis. It finally leads to the death of the insect.
