?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.

• Bacterium Bacillus thuringiensis (Bt for short) produces Bt toxin. 
• The Bt toxin-producing gene of this bacteria is cloned and then allowed to be expressed in plants. This has been found to provide resistance to insects without the need for insecticides; in effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato, and soybeans etc.
• Bt Cotton: Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans (tobacco budworm, army worm), coleopterans (beetles) and dipterans (flies, mosquitoes). B. thuringiensis forms protein crystals during a particular phase of their growth. These crystals contain a toxic insecticidal protein and help in providing resistance to the cotton plants against cotton bollworms.

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