International Research Team Discovers Genetic Mechanism that Allows Rice to Survive Flooding

An international research team comprised of Takeshi Kuroha of Tohoku University, Motoyuki Ashikari of Nagoya University, Susan R. McCouch of  Cornell University and research collaborators in Japan and the U.S.A., have discovered a gene in rice that is critical to its survival in flooded conditions. The team has also shed light on its molecular function and evolutionary history.

The research team identified a rare allele of the semi-dwarf 1 (SD1) gene to be responsible for rice's adaptation to deep water. A transcriptional gain-of-function allele of the SD1 gene enables deepwater rice to adapt to flooding via the opposite phenotypic response - an increase in plant height.

Expression of SD1 is triggered by a build-up of ethylene gas in the water that occurs when a plant is submerged. As the plant chemically senses the ethylene gas, a genetic response that activates the expression of the SD1 gene is triggered; the protein gene expression then causes a rapid increase of a unique form of the hormone gibberellin, GA4, which promotes rapid stem elongation and growth of the plant.

For more details, read the news releases from Cornell University and Tohoku University.