BBX11 Gene: Greening of Plants

• 26 Dec 2020

Why in News

Recently, the Indian Institute of Science Education and Research (IISER) has recognized the BBX11 gene that facilitates the greening of crops.

Key Points

• About BBX11 Gene:
  
  • The researchers discovered a mechanism where two proteins oppositely regulate the BBX11 gene to maintain optimum ranges of BBX11.
  • BBX11 plays a vital role in regulation of the amount of protochlorophyllide synthesized by the plant.
    
    • Protochlorophyllide is an intermediate in the synthesis of chlorophyll.
    • If it is less, plants are unable to efficiently green in order to harvest sunlight and if the amount of protochlorophyllide is more, then photobleaching occurs.
      
      • Photobleaching is loss of colour by a pigment.
    • The quantity of protochlorophyllide synthesised needs to be proportional to the variety of enzymes available to transform them to chlorophyll.
    • It is very important to regulate the amount of protochlorophyllide synthesized by the plant.
• Synthesis of Chlorophyll:
  
  • Chlorophyll is the green pigment in plants, algae, and cyanobacteria that absorbs sunlight and uses its energy to synthesise carbohydrates from Carbon-di-Oxide (CO₂) and water.
    
    • The synthesis of chlorophyll in plants is a lengthy, multi-step process.
  • When a seedling emerges from under the soil it must quickly synthesise chlorophyll to start supporting its own growth.
    
    • In order to facilitate quick synthesis of chlorophyll, plants make a precursor of chlorophyll called ‘protochlorophyllide’ in the dark, which glows red in blue light.
  • As soon as the plant comes out into the light from under the soil, light-dependent enzymes convert protochlorophyllide to chlorophyll.
• Implications:
  
  • This discovery has many implications within the agriculture sector in tropical nations like India and can assist present results in optimising plant progress in frequently changing weather conditions.
    
    • Due to the quickly altering weather conditions, farmers in a number of states in India, particularly in Maharashtra, are struggling with large losses in crop yields.
    • This often leads to severe distress among the farming community as indicated by the high number of farmer suicides in Maharashtra for the past several years.
    • Major Reasons for Crop Failure: Severe drought, high temperature and high light.
  • Young seedlings emerging out of the soil are extremely sensitive to high irradiance of light. This study can provide leads to optimise plant growth under these stressful conditions.

Photosynthesis

• Photosynthesis is the process by which green plants and certain other organisms transform light energy into chemical energy.
• During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.

• Factors Affecting Photosynthesis: Photosynthesis is under the influence of several factors, both internal (plant) and external.
  
  • Internal: Number, size, age and orientation of leaves, mesophyll cells and chloroplasts, internal CO₂ concentration and the amount of chlorophyll.
  • External: Availability of sunlight, temperature, CO₂ concentration and water.
    
    • For example, despite the presence of a green leaf and optimal light and CO₂ conditions, the plant may not photosynthesise if the temperature is very low.
• Importance:
  
  • It would be impossible to overestimate the importance of photosynthesis in the maintenance of life on Earth.
  • If photosynthesis ceased, there would soon be little food or other organic matter on Earth.
  • Most organisms would disappear, and in time Earth’s atmosphere would become nearly devoid of gaseous oxygen.
  • Energy produced by photosynthesis carried out by plants millions of years ago is responsible for the fossil fuels (i.e., coal, oil, and gas) that power industrial society.

Source:TH