August 20, 2009

Scientists Identify, Implant “˜Deepwater’ Rice Gene

Researchers in Japan have hopes of enabling farmers to grow high-yielding rice species in flood-prone areas after they have identified two genes that make rice plants grow longer stems and survive floods.

The long-stemmed deepwater rice varieties are prone to growing in frequently flooded areas and have very low yields.

"In southeast Asia, there are floods in the rainy season and deepwater rice is planted in these regions. But they have yields that are only one third or one quarter that of high-yielding rice. This is a big problem," said Motoyuki Ashikari at Nagoya University's Bioscience and Biotechnology Center.

"If we combine the deepwater genes with high-yielding rice, we can have the best combination," he said in a phone interview.

Ashikari's team analyzed the genes of deepwater rice in their experiment and they found two genes that were unique to the plant.

"The genes Snorkel 1 and Snorkel 2 are only in the deepwater variety but not in the non-deepwater variety," he said.

The team found that rice plants begin producing a lot of the plant hormone ethylene when it is grown in deeper water.

"As water levels rise, accumulation of the plant hormone ethylene triggers expression of the Snorkel genes, which in turn switches on rapid stem growth," they wrote.

Later, the scientists tested their discovery by inserting two genes into a non-deepwater variety of rice and found that it grew longer stems, enabling it to survive in deep waters.

"It's hoped that the findings will help researchers to breed rice that can be grown in lowland areas that are frequently flooded during the rainy season," they wrote in a statement.