Summary

Biotechnological applications in agriculture focus on producing genetically modified (GM) crops with traits like tolerance to abiotic stresses, reduced reliance on chemical pesticides (pest resistance, e.g., Bt cotton), fewer post-harvest losses, more efficient mineral usage, and enhanced nutritional value (e.g., Golden Rice with beta-carotene). The Bt toxin gene from Bacillus thuringiensis encodes a protein that kills specific insects; in Bt cotton, the cryIAc or cryIIAb gene is inserted to control bollworms (cryIAb instead targets the corn borer). Tissue culture and micropropagation separately allow rapid, large-scale, disease-free propagation of plants.

RNA interference (RNAi) is a gene-silencing mechanism used to develop pest-resistant plants. A double-stranded RNA (dsRNA) complementary to a pest's essential gene triggers its degradation, protecting the plant — e.g., in tobacco against the nematode Meloidogyne incognita.

Applications in medicine include the production of recombinant therapeutics. Human insulin (Humulin) was the first recombinant drug, produced in E. coli by inserting the A and B chains separately.

Gene therapy aims to correct genetic disorders by introducing a functional gene. The first approved case was for Severe Combined Immunodeficiency (SCID) due to adenosine deaminase (ADA) deficiency: lymphocytes were corrected ex vivo using a retroviral vector carrying the ADA gene and re-infused. …