Model Answer
0 min readIntroduction
Transgenic technology, also known as genetic modification, involves introducing foreign genes into an organism's genome to impart desired traits. With increasing food demand and post-harvest losses, enhancing the shelf life of agricultural produce is crucial. Globally, transgenic crops contribute significantly to reducing wastage and improving food security. In India, while the adoption of transgenic technology remains limited due to regulatory and public perception challenges, research continues on improving the post-harvest characteristics of various crops. This answer will discuss the role of transgenic technology in extending the shelf life of fruits, vegetables, and flowers.
What is Transgenic Technology?
Transgenic technology leverages recombinant DNA technology to introduce genes from one organism into another, creating organisms with new or improved traits. These genes, often from bacteria, viruses, or other plants, are inserted into the target organism's genome, leading to the expression of the desired characteristic. This differs from traditional breeding, which relies on natural genetic variation.
Role of Transgenic Technology in Enhancing Shelf Life
Transgenic technology offers several avenues for extending the shelf life of fruits, vegetables, and flowers. These can be broadly categorized by the mechanism they employ:
1. Delayed Ripening
- Mechanism: Transgenes can interfere with the ripening process by modulating ethylene production, a key hormone responsible for fruit ripening.
- Example: The Flavr Savr tomato (developed by Calgene) was the first commercially available genetically modified food. It contained a gene that inhibited the production of polygalacturonase, an enzyme that breaks down pectin in cell walls, delaying softening and extending shelf life. Though discontinued, it remains a significant example.
2. Reduced Ethylene Production
- Mechanism: Directly reducing the production of ethylene, or blocking its action, can significantly slow down ripening.
- Example: Research is ongoing on papaya varieties in India (e.g., Bharia papaya) that are resistant to Papaya Ringspot Virus (PRSV) and also exhibit delayed ripening due to altered ethylene production.
3. Increased Resistance to Decay-Causing Microorganisms
- Mechanism: Introducing genes that produce antimicrobial compounds or enhance the plant’s natural defenses can reduce spoilage caused by bacteria and fungi.
- Example: Studies are exploring the introduction of genes encoding chitinase and glucanase (enzymes that degrade fungal cell walls) into various fruits and vegetables to combat post-harvest fungal decay.
4. Modified Cell Wall Structure
- Mechanism: Altering the composition of cell walls can reduce softening and bruising during handling and transportation.
- Example: Research is underway to modify pectin esterification levels in apples to improve firmness and reduce softening.
Regulatory Landscape in India
In India, the Genetic Engineering Appraisal Committee (GEAC) under the Ministry of Environment, Forest and Climate Change regulates the introduction of transgenic crops. Strict biosafety assessments and field trials are mandatory before commercial release. Public concerns regarding the potential environmental and health impacts have led to a cautious approach. The Cartagena Protocol on Biosafety, an international treaty, also influences India’s regulatory framework.
| Crop | Transgene/Mechanism | Benefit |
|---|---|---|
| Papaya | PRSV resistance & altered ethylene production | Reduced disease incidence and extended shelf life |
| Tomato (Flavr Savr) | Inhibition of polygalacturonase | Delayed softening |
| Apple | Modified pectin esterification | Improved firmness |
Conclusion
Transgenic technology holds significant promise for enhancing the shelf life of fruits, vegetables, and flowers, thereby reducing post-harvest losses and improving food security. While the technology offers compelling benefits, careful consideration of potential environmental and health impacts, coupled with robust regulatory oversight, is essential. Continued research and public dialogue are crucial to harness the potential of transgenic technology responsibly and sustainably in India's agricultural sector.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.