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.

[news.cornell.edu]
ewly-discovered-genetic-mechanism