What is Bt toxin? Name an organism that produces it? How has man exploited it?

• Bt toxins are the protein crystals produced by Bacillus thruingensis.

• These toxins are insecticidal in nature.

• When an insect ingest bt toxin, the protoxin converts into active form due to the alkaline nature of gut, the Bt toxin binds with the lining of gut, creates pore, causing death of insect.

• This insecticidal property is used by mankind by taking out the cry gene which is known to encode for Bt toxin.

• And this Cry gene is introduced into the plants. So that whenever an insect ingest, the cotton plants would die.