Outline the use of genetic modification in crop plants by inserting genes: (a) to confer resistance to herbicides (b) to confer resistance to insect pests (c) to provide additional vitamins

SouravNovember 4, 2024

Answer

Genetic modification in crop plants has become a vital tool for enhancing agricultural productivity and nutritional value. This process involves inserting specific genes to confer desirable traits. Here’s an outline of the use of genetic modification in crop plants, focusing on three key applications:

(a) Conferring Resistance to Herbicides

• Mechanism: Genetic modification can create crops that are resistant to specific herbicides, allowing farmers to control weeds without harming the crops. This is achieved by inserting genes that enable the plant to detoxify or tolerate the herbicide.
• Examples:
  • Glyphosate Resistance: Crops such as Roundup Ready soybeans have been genetically modified to express a bacterial gene that produces an enzyme capable of breaking down glyphosate, the active ingredient in many herbicides. This allows these crops to survive applications of glyphosate while weeds are eliminated.
  • Glufosinate Resistance: Some crops have been engineered with a gene from Bacillus thuringiensis that allows them to detoxify glufosinate, another herbicide, thus enabling effective weed management without damaging the crop itself.

(b) Conferring Resistance to Insect Pests

• Mechanism: Genetic engineering can enhance a plant’s resistance to insect pests by incorporating genes that produce insecticidal proteins or enhance natural defenses.
• Examples:
  • Bt Crops: Crops such as Bt cotton and Bt corn are engineered to express Bacillus thuringiensis delta-endotoxins, which are toxic to specific insect pests. When these insects consume parts of the plant, the toxins disrupt their digestive systems, leading to mortality. This reduces the need for chemical insecticides and promotes sustainable pest management.
  • Multi-gene Constructs: Some crops have been modified to express multiple insecticidal proteins, increasing their effectiveness against a broader range of pests. For instance, transgenic tomatoes expressing synthetic cry genes have shown significant mortality rates against pests like the tomato leaf miner.

(c) Providing Additional Vitamins

• Mechanism: Genetic modification can also enhance the nutritional profile of crops by inserting genes responsible for synthesizing essential vitamins or nutrients.
• Examples:
  • Golden Rice: One of the most notable examples is Golden Rice, which has been genetically modified to produce beta-carotene, a precursor to vitamin A. By inserting genes from daffodils and bacteria, this rice accumulates beta-carotene in its endosperm, addressing vitamin A deficiency in populations that rely heavily on rice as a staple food .
  • Iron and Folate Biofortification: Other crops have been engineered to increase their iron and folate content. For example, researchers have manipulated pathways in rice and cassava to enhance iron absorption and storage, significantly improving nutritional value