"Sub1A effectively makes the plant dormant during submergence, allowing it to conserve energy until the floodwaters recede," said Dr. Bailey-Serres.
Typically, rice plants will extend the length of their leaves and stem in an attempt to escape submergence. The Sub1A gene is an evolutionarily new gene in rice found in only a small proportion of the rice varieties originating from eastern India and Sri Lanka. The activation of this gene under submergence counteracts the escape strategy.
"This project has been a great success, not only in its results but also in the truly international collaboration that made the project possible," said Dr. Mackill, referring to the several national organizations, including the Bangladesh Rice Research Institute, India's Central Rice Research Institute and Narendra Dev University of Agriculture and Technology.
"The potential for impact is huge," he said. "In Bangladesh, for example, 20% of the rice land is flood prone and the country typically suffers several major floods each year. Submergence-tolerant varieties could make major inroads into Bangladesh's annual rice shortfall and substantially reduce its import needs."
Using modern techniques that allow breeders to do much of their work in the lab rather than the field, Dr. Mackill and his team at IRRI were able to precisely transfer Sub1A into high-yielding varieties without affecting the characteristicssuch as high yield, good grain quality, and pest and disease resistancethat made the varieties popular in the first place.
"The impact is evident for farm families as well as at a national production level," said Dr. Ronald. "To be part of this project as it has moved from a lab in California to rice fields in Asia has been inspiring and underscores the power of science to improve people's lives."
Because plants developed through this "precision breeding," known as marker-assisted selection, are not ge
|Contact: Adam Barclay|
International Rice Research Institute