Role of zinc in Nitrogen Fixation

Source: Down to Earth

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Context

• Research reveals zinc's vital role in legume crops, promotes nitrogen fixation and crop resilience. Study published by Aarhus University and Polytechnic University of Madrid.

Details

Key Points

Discovery	French researchers discovered zinc's crucial role in legume crop health that helps in nitrogen fixation.
Institutions	Aarhus University, Denmark and Polytechnic University of Madrid
Publication	Nature journal
Applications	The discovery applicable to legumes like fava beans, soyabeans and cowpeas

• Zinc helps in nitrogen fixation by converting atmospheric nitrogen into ammonia.
• Legumes forms symbiotic relation with rhizobia bacteria that fixes atmospheric nitrogen in root nodules.
• Root nodules are sensitive to high temperatures, flooding, drought, soil salinity and high soil nitrogen levels.
• The study also finds a transcription factor i.e. Fixation Under Nitrate (FUN) by controlling nodule breakdown when there are high soil nitrogen levels.
• Zinc acts as a secondary signal by integrating environmental factors to regulate nitrogen fixation efficiency.
• Agricultural Benefits:
  • Increased nitrogen availability for legume crops and subsequent crops.
  • It helps in reducing need for synthetic fertilizers thereby decreasing environmental and economic costs.
  • It enhances crop yields and acts as a climate resilient.

Nitrogen Fixation:

• Nitrogen fixation is a process where atmospheric nitrogen (N₂) is converted into usable forms for plants and other organisms.
• Atmospheric nitrogen cannot be utilized directly by most of the organisms. Therefore, making nitrogen fixation is essential for life on earth.
• Types of Nitrogen Fixation:
  • Biological nitrogen fixation which is carried out by specific bacteria and cyanobacteria (diazotrophs). For example: Rhizobium bacteria, Azotobacter
  • Abiotic nitrogen fixation which occurs naturally through lightning strikes and ultraviolet radiation from the sun.
• Importance of Nitrogen Fixation:
  • It provides for continuous supply of usable nitrogen for plants.
  • It maintains soil fertility and supports healthy ecosystems.
  • It reduces dependence on synthetic nitrogen fertilizer.
• Nitrogen Cycle:

Sources:

Down to Earth

PRACTICE QUESTION Q. Which of the following is the enzyme responsible for breaking the triple bond in N₂ during biological nitrogen fixation? a) Nitrate reductase b) Nitrogenase c) Nitrosomonas d) Decomposer Answer: b)