Context:
Researchers have shown that lowering nitric oxide (NO) levels in plants greatly enhances both nitrogen absorption and Nitrogen Use Efficiency (NUE) in rice and Arabidopsis.
Sustainable Agricultural Practices: Nitric Oxide Reduction
- Key Findings:
- Promising approach for sustainable agriculture by reducing NO levels in plants.
- Significance of Nitric Oxide (NO):
- NO regulates various physiological processes in plants.
- Lowering NO levels activates High-Affinity Nitrate Transporters (HATs).
- High-Affinity Nitrate Transporters (HATs):
- Essential for nitrogen uptake, especially in low nitrogen conditions.
- Highly effective when NO levels are reduced.
Nitrogen Use Efficiency (NUE):
- Describes the efficiency of plants in using nitrogen for biomass production.
- Measured as the ratio between crop yield and the nitrogen absorbed from soil or atmosphere.
- Important trait in crop breeding programs to improve yield while reducing input costs and keeping nitrogen out of the environment.
- Issues with Traditional Methods:
- Enhancement of NUE often involves applying inorganic nitrogen fertilizers.
- Significant drawbacks: increased operational costs for farmers and environmental issues.
- Emission of nitrogen oxides (NOx) during fertilizer production.
- Excessive use contributes to global greenhouse gas emissions.
Methods to Improve Nitrogen Use Efficiency (NUE):
- Pharmacological Manipulation:
- Use of chemical compounds (NO scavengers) to reduce NO concentration in plants.
- Overexpressing Phytoglobin:
- Phytoglobin, a natural NO scavenger, overexpressed in plants.
- Increased expression of high-affinity nitrate transporters (HATs) like NRT2.1 and NRT2.4.
- Enhanced nitrogen uptake under low NO conditions.
- Genetic Manipulation:
- Altering plant genes to regulate NO levels in cells.
- Protein Nitrosylation:
- Protein nitrosylation, a biochemical modification by NO, plays a significant role in nitrogen regulation.
- Targeting protein nitrosylation shows potential in improving NUE.
Importance of Improving Nitrogen Use Efficiency (NUE):
- Enhancing NUE reduces the excessive use of nitrogen fertilizers.
- It mitigates environmental pollution, including nitrate leaching and greenhouse gas emissions.
- Improved NUE
Source: PIB
Previous Year Question
What is the use of biochar in farming?
1. Biochar can be used as a part of the growing medium in vertical farming.
2. When biochar is a part of the growing medium, it promotes the growth of nitrogen-fixing microorganisms.
3. When biochar is a part of the growing medium, it enables the growing medium to retain water for longer time.
Which of the statements given above is/are correct?
[UPSC CSE – 2020 Prelims]
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d)