Question

Highlight any four areas where genetic modification of plants has been useful.

Answer 1

Introduction of genetically modified crops :

Genetically modified crops are the crops that contain genes from other plants or organisms to enhance various desirable characteristics in them such as improved nutritional status, increased yield, disease resistance etc.

Yield of crops :

Genetic modifications enhance the yield of the crops which can meet the increasing demand of the population.

Enhancing nutritional value:

GM crops have enhanced nutritional value.

• For example, golden rice which has been engineered to contain the gene encoding precursor (beta carotene) of vitamin A.
• The gene for vitamin A was isolated from Narcissus pseudonarcissus (daffodil) and inserted into the Oryza sativa (rice) using the Agrobacterium as a vector.

Tolerance to abiotic stress:

GM crops are more tolerant to drought, soil salinity, heat and cold etc.

• A tomato variety called ‘Flavr Savr’, that remains fresh for a long period is developed by antisense RNA. The gene responsible for ripening is silenced in this case.

Reducing dependency on pesticides, insecticide:

GM crops are less dependent on pesticides and insecticides as they are genetically pest-resistant.

• By RNA interference technology, the tobacco plant is made resistant to root knot nematodes (Meloidogyne incognita).
• By inserting the toxin synthesizing gene from Bacillus thuringiensis into plants such as cotton, corn, tomato, potato etc, thus making them resistant to insects such as Lepidoptera, Coleoptera and Diptera.

Medically important products :

GM plants are used for the production of medically important products. :

• The gene encoding the synthesis of hirudin (anticoagulant) was chemically synthesized and introduced into Brassica napus by Agrobacterium mediated transformation. The hirudin from its seeds is purified and used as medicine.