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Cry1 endotoxins obtained from Bacillus thuringiensis are effective against:
A
Nematodes
B
Boll worms
C
Mosquitoes
D
Flies
Detailed Solution
Bacillus thuringiensis produces insecticidal protein crystals during a particular phase of its growth. The toxin is coded by a gene named cry.
The protein exists as an inactive protoxin. In the alkaline pH of the insect gut it is solubilised and activated; it then binds to the midgut epithelial cells and creates pores, causing swelling, lysis and death of the insect.
There are a number of cry genes, and the toxins they code for are specific to particular groups of insects.
The proteins encoded by the genes cryIAc and cryIIAb control the cotton bollworms, and that of cryIAb controls the corn borer. These are lepidopteran insects.
Other Bt toxins act on dipterans (flies and mosquitoes) and coleopterans (beetles), but the Cry1 group is specific for lepidopterans such as bollworms.
So Cry1 endotoxins are effective against boll worms.
The protein exists as an inactive protoxin. In the alkaline pH of the insect gut it is solubilised and activated; it then binds to the midgut epithelial cells and creates pores, causing swelling, lysis and death of the insect.
There are a number of cry genes, and the toxins they code for are specific to particular groups of insects.
The proteins encoded by the genes cryIAc and cryIIAb control the cotton bollworms, and that of cryIAb controls the corn borer. These are lepidopteran insects.
Other Bt toxins act on dipterans (flies and mosquitoes) and coleopterans (beetles), but the Cry1 group is specific for lepidopterans such as bollworms.
So Cry1 endotoxins are effective against boll worms.