Gene Researchers Work on Flood-Resistant Rice lead, discovery, identified, completely, English

李武军

This is the VOA Special English Agriculture Report.
Rice plants normally grow well in standing water. But most will die if they are completely underwater for more than four days. Now, researchers have identified a gene that lets rice survive longer underwater. They say the discovery will lead to new kinds of rice plants that can survive flooding. And that could mean more dependable food supplies.
Tests are now being done in Laos, Bangladesh and India. The researchers say experimental rice plants with the gene have survived underwater as long as two weeks.
Two teams worked together on the research. One was from the International Rice Research Institute in the Philippines. The other was from the University of California at Davis and Riverside.
When flooding happens, most kinds of rice plants cannot get enough oxygen, carbon dioxide or sunlight. But the scientists say crop loss depends on several conditions. These include water depth and plant age. Others include the amount of time the plant is underwater and the rate of nitrogen fertilizer used on the crop.
On a genetic map of rice, the scientists became interested in a group of three genes. They experimented with one of them, a gene known as Sub-One-A. They found that when this gene is made to become very active, it improves the ability of rice to survive longer when covered by water. They believe it succeeds because it affects the reaction to hormones that govern the ability of a flooded plant to survive.
The researchers then placed the gene into rice plants that are especially good for conditions in India. They say the genetically engineered plants not only survived but also produced good crops.
American and German government agencies paid for the study. Nature magazine published the results in August.
The researchers are now trying to identify all the genes governed by the Sub-One-A gene. Being able to leave water on rice plants for an additional week might also help farmers suppress the growth of weeds. Less weed growth around their crops would mean less need for herbicide chemicals.
Finally, we reported last week on the recent outbreak of E. coli infections in the United States from fresh spinach. On Friday the government announced that all the bad spinach came from one California grower and processor, Natural Selection Foods. Officials continue to investigate the cause.
And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. For more reports, including transcripts and MP3 files, go to WWW.51VOA.COM. I'm Steve Ember.