Question

Is there a way to minimise the use of fertilisers and chemicals so that their harmful effects on the environment are reduced?

Answer 1

Part 1: Introduction to rDNA technology
Recombinant DNA technology, commonly called rDNA technology, is a combination of methods employed to manipulate the DNA by inserting or deleting a gene/ desired DNA sequence and then introducing this modified DNA into the desired organism.

Part 2: Impact of rDNA in agricultural avenues
Yes, there is a way to minimise the use of harmful fertilizers and chemicals. This can be done by genetically modifying the crops using rDNA technology, making them naturally resistant to insects and pests as well as enhancing their yield. Addition of these desired traits would minimise the requirement of application of chemicals on plants.

Part 3: Methods to reduce the use of fertilisers and chemicals

• Using rDNA technology, genes which confer resistance to insects can be introduced in plants to reduce the dependence on pesticides.

For example: The cry gene encoding Bt toxin (Cry protein) can be introduced in the plants using rDNA technology. This will make the plants resistant to the target pest. For example, proteins/ toxins encoded by the genes cryIAc and cryIIAb control the cotton bollworms while that of cryIAb helps control corn borers.

• Biofertilizers can be used such as nitrogen-fixing soil bacteria (Azotobacter, Rhizobium etc.), nitrogen-fixing cyanobacteria (Anabaena, Nostoc etc.) to fix nitrogen in the soil instead of using chemical fertilisers.
• Baculoviruses can be used as biopesticides.
• RNA interference technique is utilised to get pest-resistant plants. For example, resistance of transgenic tobacco plants towards Meloidogyne incognita.