Image caption Rice is the staple food for about half of the world's population

A gene that increases a rice plant's resistance to floods also boosts its ability to recover from droughts, a study has shown.

Researchers found that the gene, Sub1A, allowed to plants to survive by growing fresh shoots after a period of drought.

Rice is the primary food for three billion people, and more than 25% the world's harvest is grown in areas that experience extreme weather conditions.

Details have been published in the journal The Plant Cell.

"Flood tolerance does not reduce drought tolerance in these plants, and appears to even benefit them when they encounter drought," observed lead author Julia Bailey-Serres from the University of California Riverside's department of botany and plant sciences.

The gene's role in providing rice plants with a higher tolerance of being submerged in water was first identified in 2006, just 12 months after the vital food crop's complete genome was unscrambled.

Professor Bailey-Serres and her team wanted to follow up the discovery of the "flood-proof" trait provided by the presence of the Sub1A gene did not reduce plants' ability cope with other environmental stresses - such as drought.

Image caption A rice plant containing the Sub1A gene (at right in each image) recovered significantly better after a simulated drought

They reported that the gene served as a point where the pathways of the plant's response to both submergence and drought, resulting in the crop's ability to survive and recover from either kind of extreme weather event.

"Our findings suggest that the plant recovers well from drought and growing new shoots," Professor Bailey-Serres said. "This is something that is also seen with flooding."

Plant breeders have already utilised the gene's flood tolerance traits and transferred it into high-yielding varieties.

The researchers said the next stage of the research would involve scientists at the International Rice Research Institute (IRRI) plant specimens containing the Sub1A gene in field trials to see if they display a similar trait in natural conditions.