Genetically Modified (GM) crops
Overview:
The increase in global population has increased the demand for food grains. Meanwhile, in order to cater to this ever-growing need, it is also imperative to not consider deforestation; excessive pesticide use damages soil and groundwater.
- The article discusses genetically modified (GM) crops that offer a potential solution, improving yields and reducing the need for harmful agricultural practices.
Relevance:
GS-03 (Conservation)
Dimensions of the Article:
- About GM crops
- What is CRISPR and its Applications?
- Significance of GM Crops
- Disadvantages of GM crops
About GM crops:
- GM crops are plants whose genomes are altered by inserting a specific stretch of DNA into the plant’s genome to exhibit desirable traits like pest resistance or herbicide tolerance.
- Top GM-growing countries: USA, Brazil, Argentina, India, and Canada.
- Examples:
- Bt cotton in India and Bt brinjal in Bangladesh contain genes from the bacterium Bacillus thuringiensis. This gene enables the plant to produce toxins harmful to certain pests.
- Herbicide-tolerant (HT) crops allow farmers to target weeds without harming the crops.
- Benefits:
- They reduce the dependence on pesticides, lowering the risks of poisoning, especially for farmers without protective gear.
- Enhanced productivity through higher yields and nutrient-rich crops.
- GM crops support no-till or conservation agriculture practices. This helps retain soil carbon, improves soil health, and reduces greenhouse gas emissions, contributing to climate change mitigation.
What is CRISPR and its Applications?
- CRISPR is a gene-editing tool allowing scientists to make precise changes in a plant’s genome.
- It stands for Clustered Regularly Interspaced Short Palindromic Repeats.
- CRISPR-Cas9 edits the parts of the genome by either removing, adding, or altering sections of the DNA sequence.
- It has two key molecules:
- Cas9: This enzyme acts as a’molecular scissors’ that can cut the two strands of DNA at a specific location in the genome.
- Guide RNA (gRNA): The gRNA work is to find and bind to the specific sequence in the DNA.
- It has two key molecules:
- The guide RNA guides the Cas9 to the same location in the DNA sequence and allows Cas9 to make a cut across both strands of the DNA.
- At this stage, the cell recognises that the DNA is damaged and tries to repair it.
- The DNA repair machinery is used to introduce changes to one or more genes in the genome of a cell of interest.
- The technology replicates a natural defence mechanism in some bacteria that uses a similar method to protect itself from virus attacks.
- Applications in GM crops:
- Reduces development costs by making targeted genetic modifications.
- Creates GM crops without introducing foreign genes, improving public acceptance.
- Equips crops with stacked resistance genes to combat pest and weed resistance effectively.
Significance of GM Crops
- Economic and Social Impact: It helps farmers to save their money and efforts by reducing the dependence on pesticides and labour-intensive practices. It also helps address global food demand without expanding agricultural land by indulging in deforestation.
- Environmental Benefits: It majorly limits deforestation and excessive use of agro-chemicals and also reduces carbon emissions through no-till farming practices.
Disadvantages of GM crops:
- Health Risks: Horizontal gene transfer of pesticide, herbicide, or antibiotic resistance to other organisms could harm humans and disrupt ecosystems, potentially spreading diseases among plants and animals.
- Herbicide Resistance: Overuse of herbicides, like glyphosate, has led to herbicide-resistant weeds, reducing their effectiveness over time.
- Impact on Pollinators: Concerns persist that GM crops may harm honeybee populations and other pollinators, crucial for ecosystem health.
- Pest Resistance: Pests may adapt to pest-resistant traits, like Bt toxins, diminishing the crops’ protective benefits.
- Genetic Diversity: GM crops risk reducing genetic diversity in nearby crops, wild relatives, and weeds, impacting agricultural resilience.
Way Forward
- Integrated Pest Management: The use of herbicides should be done carefully to also allow some weeds in fields to balance ecosystems.
- Crop rotation: Crop rotation should be practiced to reduce reliance on agro-chemicals and disrupt pest cycles.
- Improved Regulation: The government should shift its focus from GM crop methods to the traits and impacts they create so that balance can be maintained alongside reaping its benefits.
