Lead researcher Prof Stephen Long, based at the University of Illinois and the University of Lancaster, said decades of research into the 140-step process by which plants convert sunlight energy into food had revealed specific "inefficiencies in crops".
The scientists targeted a plant's natural sun-protection mechanism. While plants have evolved to produce food using sunlight energy, they have also evolved to protect themselves from sun damage, which slows the process down. Field trials using tobacco plants modified with extra copies of the genes responsible for this heat-loss switch showed increased yields of up to 20%.
The team have now been funded by the Gates Foundation to introduce similar modifications in major food crops, starting with rice, soya bean and cassava.
"This is a big jump," said Prof Long. "We're now making this change in rice, in soy bean and wheat. Globally - rice, wheat, maize and soybean are the biggest crops. So if we could get the same increase in those, that would greatly alleviate what we see as the future pressure on food supply. "