What triggers activation of protoxins to active Bt toxin of Bacillus thuringinensis in boll worm?
Body temperature
Moist surface of midnight
Alkaline pH of gut
Acidic pH of stomach
Bacillus Thuringiensis -
Bacillus Thuringiensis is a Gram-positive bacteria; During sporulation this bacteria forms crystals of proteins or (cry protein), which are coded by cry genes (Cry 1 AC) Cry genes are used to make insecticide transgenic plants.
- wherein
When insects ingest crystal proteins , the alkaline pH of gut denature the insoluble protein into soluble. Soluble proteins makes gut porous and cause death of insect (Lepidopteran)
The toxins present in Bacillus thuringinesis remain as inactive protoxins which when enters gut of insect gets activated. The alkaline pH of insect gut activates the protoxin into active toxin.
The toxin then binds to specific receptors in the gut and causes the gut wall to breakdown. The insectidies as the bacteria proliferates.
Body temperature
Option 2)Moist surface of midnight
Option 3)Alkaline pH of gut
Option 4)Acidic pH of stomach