The technique involves the use of a popularly known biopesticide Bt toxin produced by bacteria Bacillus thuriengiensis. Bt toxin protein when ingested by the insect gets converted to its active form due to alkaline pH of the gut. The activated toxin binds to the surface of midgut epithelial cells. It creates pores in these cells that cause swelling and lysis and eventually kills the insect. The genes (cry genes) encoding this protein are isolated from the bacterium and incorporated into crop plants like cotton. The proteins encoded by these cry genes control the pest. Specifically, cryIAc and cryIIAb control cotton bollworm (Helicoverpa armigera), an insect belonging to Lepidoptera which earlier used to destroy the whole crop.
