Researchers at the Indian Institute of Science Education and Research (IISER) have identified a gene 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.
Dr. Sourav Datta, Associate Professor, Department of Biological Sciences, IISER Bhopal, and a PhD research student Nikhil Job have identified the gene ‘BBX11’ and their study was recently published in the prestigious British journal New Phytologist.
“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 when blue light is shone on the plant. As soon as the plant comes out into the light from under the soil, light-dependent enzymes convert protochlorophyllide to chlorophyll,” explained Dr. Datta.
Using genetic, molecular and biochemical techniques, the duo found a mechanism where two proteins oppositely regulate the ‘BBX11’ gene to maintain optimum levels of ‘BBX11’. Dr. Datta said that 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,” he explained.
According to Dr. Datta, the study could have tremendous implications in the agriculture sector in tropical countries like India and can help provide leads to optimise plant growth under stressful and rapidly changing climatic conditions. Due to the rapidly changing climatic conditions, farmers in several states in India, especially in Maharashtra, are suffering huge 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. Severe drought, high temperature and high light are some of the major reasons for crop failure. 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,” Dr. Datta said.