By K.S.Jayaraman

Bengaluru, Nov 28 (IANS): Researchers in the US, led by one of Indian origin, have developed a genetic manipulation technique that results in more efficient use of sunlight in photosynthesis by plants. They say the findings observed in tobacco plants could potentially be used to increase the yield of food crops like wheat and rice.

Photosynthesis is a process in which green plants use energy from the sun to transform water, carbon dioxide and minerals into biomass that is used for food, fuel, and fibre.

However, when there is too much sunlight, the photosynthetic machinery in chloroplasts inside the plant cells can be damaged. To protect plants from such damage, nature has endowed the chloroplasts with a system called non-photochemical quenching or NPQ.

Scientists at the University of California-Berkeley (UCB) and the University of Illinois targeted the three genes involved in the "quenching" process. They figured that boosting the expression of these genes might improve photosynthetic efficiency and hence yield. To test this concept, the team inserted a "cassette" of the three genes (taken from the model plant Arabidopsis) into tobacco plants for testing in the field.

By boosting the expression of the three genes involved in NPQ, the scientists saw up to 20 per cent increase in the productivity of the modified tobacco plants in field experiments. The researchers have reported their findings in a paper published in the journal "Science".

"We just used tobacco plant for the proof of concept experiments because it is easy to work with," Krishna Niyogi, a UCB professor of plant and microbial biology and co-senior author, told this correspondent in an email.

"All plants have the NPQ photo-protection system. So we expect this will work for food crops too," Niyogi said, adding: "In plants like rice and wheat, we hope to see an increased yield of seeds, which are the harvested parts of those crops."

Niyogi teamed up with Stephen Long, a plant biology and crop sciences professor at the University of Illinois, for the study.

"It is very important to have these new technologies on the shelf now because it can take 20 years before such inventions can reach the farmer's fields," an official release from the university quoted Long as saying. "If we don't do it now, we won't have this solution when we need it."