Role of biotechnology in agriculture

• Let us take a look at the three options that can be thought for increasing food production

1. agro-chemical based agriculture;
2. organic agriculture; and
3. genetically engineered crop-based agriculture.

• Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). GM plants have been useful in many ways. Genetic modification has:

1. made crops more tolerant to abiotic stresses (cold, drought, salt, heat).
2. reduced reliance on chemical pesticides (pest-resistant crops).
3. helped to reduce post harvest losses.
4. increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil).
5. enhanced nutritional value of food, e.g., Vitamin ‘A’ enriched rice.

• In addition to these uses, GM has been used to create tailor-made plants to supply alternative resources to industries, in the form of starches, fuels and pharmaceuticals.
• Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short).
• Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as tobacco budworm, armyworm, beetles and dipterans flies, mosquitoes.
• Why does this toxin not kill the Bacillus? Actually, the Bt toxin protein exist as inactive protoxins but once an insect ingest the inactive toxin, it is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals.
• Bt toxin gene has been cloned from the bacteria and been expressed in plants 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 soyabean etc.