Question

In Bt cotton, the Bt toxin present in plant tissue as protoxin is converted into active toxin due to

• A. alkaline pH of the insect gut
• B. acidic pH of the insect gut
• C. action of gut microorganisms
• D. presence of conversion factors in insect gut

Answer 1

The correct option is A alkaline pH of the insect gut

The Bt toxin is an inactive protoxin, which is activated due to the presence of alkaline pH in the insect gut. Bt toxin dissolves in high (alkaline) pH of insect gut and becomes active. The toxin binds to the surface of midgut epithelial cells and creates pores that cause cell swelling and lysis eventually followed by the death of the insect.