Biotechnology and it's application in plant

Biotechnology Application in agriculture:

(1) agrochemical based  agriculture.

(2) organic agriculture: and

(3) genetically engineered crop based agriculture.

Use of genetically modified plants :-

• To enhance nutritional quality of food
• Made crop more tolerant to abiotic stress (cold, drought,salt heat).
• Help to reduce post harvest loss             eg. Flavr savr Tomato:transgenic variety of tomato - flavr savr due to the inhibition of polygalacturonas enzymes which degrade pectin so that tomato variety remain fresh and retain flavour much longer . Flavr savr Tomato develop why antisense Technology .
• Increase efficiency of mineral uses by plant.
• To produce bio pharmaceutical product.           Produce of Hirudin.  Hirudin is a protein that prevents blood clotting.
• To produce herbicides resistance plant.

         Pest resistant crop:

 (1) insect resistance plant

example Bt cotton .

some strain of Bacillus thurigensis produce proteins that kill certain insect such as lepidoptera (Tobacco budworm ,armyworm ), coleoptera (Beetles ) , and Dipteran ( flies, mosquitoes . 

B.thurigiensis forms protein crystal  during a particular pase  of growth .

These crystal contain toxic insecticidal protein.

 Bt toxin protein exist as inactive protoxin but insect ingest the toxin .

 it is converted into an active form of toxin due to the alkaline pH of the gut  which lies the crystal .

the activated toxin bind to the surface of midgut epithelial cells and create pore that cause cells swelling and lysis and cause death of the insect .

Bacillus thurigensis produce crystal cry protein .

 gene encoding cry protein is called cry gene.

Proteins encoded by the gene cryIAc and cryIIAb control  cotton bollworms.

(2) Nematodes resistance plant

Nematodes are parasite on plant and animal including human beings.

Prevent from Nematodes which was based on the process of RNA interference.

 RNA interference takes place in all eukaryotic organism as a method of cellular defence.

mRNA  are complementary dsRNA molecule that bind to and prevent translation of mRNA.

using agrobacterium vector 

nematode specific gene introduced into the host plant .

the introduction of DNA was such that produce both sense and antisense RNA in the host cells.

These two  RNA being complementary to each other form double standard that initiated RNA interference And the silence the specific mRNA of the nametoad.