Gene ‘BBX11’ That Greens Plants


  • Researchers at the Indian Institute of Science Education and Research (IISER) have identified a gene ‘BBX11’ that facilitates in the greening of plants by playing a crucial role in regulating the levels of protochlorophyllide — an intermediate in the biosynthesis of the green pigment chlorophyll.
  • 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. As soon as the plant comes out into the light from under the soil, light-dependent enzymes convert protochlorophyllide to chlorophyll.
  • The scientists found a mechanism where two proteins oppositely regulate the ‘BBX11’ gene to maintain optimum levels of ‘BBX11’.
  • The amount of protochlorophyllide synthesised needed to be proportional to the number of enzymes available to convert them to chlorophyll. If there is excess of free protochlorophyllide, then exposure to light converts it into molecules that cause ‘photobleaching’.
  • Thus, it is very important to regulate the amount of protochlorophyllide synthesized by the plant and here comes the vital plant played by the ‘BBX11’ gene. If it is less, plants are unable to efficiently ‘green’ in order to harvest sunlight. If the amount of protochlorophyllide is more, then plants bleach under the light.