Sept. 20 (UPI) -- Currently, rice is the only crop staple that can withstand flooding. But with floods in some parts of the world expected to increase in severity and frequency as a result of climate change, scientists are working hard to develop more resilient crops.
New research, published this week in the journal Science, suggests long dormant genes can be turned on to help crops survive extreme weather.
Rice was domesticated from a wild species native to the tropics, where the grain evolved to endure heavy rains and flooding. Other grains possess the same genes as rice, but they remain silenced even when the crops experience flood conditions.
For the study, scientists analyzed gene expression in the root cells from rice plants, as well as the root cells of a wild-growing tomato, a tomato used for farming and a plant similar to alfalfa. Scientists made a list of the many genes activated in the root cells of flooded rice plants.
"We looked at the way that DNA instructs a cell to create particular stress response in a level of unprecedented detail," Mauricio Reynoso, researcher at the University of California, Riverside, said in a news release.
When scientists compared the genetic response of the rice plants with the tomato and alfalfa plants, they found the plants share 68 families of the activated rice genes in common.
"This is the first time that a flooding response has been looked at in a way that was this comprehensive, across evolutionarily different species," said Siobhan Brady, an associate professor of plant biology at the University of California, Davis.
The genes responsible for flood resilience are called submergence up-regulated families, or SURFs. Though the tomato and alfalfa plants host many of the same flood-proofing genes, they fail to activate the SURFs in response to flooding.
In followup studies, scientists at UC Davis and Emory University activated SURFs in the tomato and alfalfa plants. The SURFs proved to be no use to the wild tomato species, which prefers desert soil. The wild tomato withered and died when flooded. The other two plants appeared to benefit from the activated SURFs, but their genetic responses were not as effective as in rice.
Scientists are currently conducting similar analysis and tests involving genes responsible for drought and heat resistance.
The researchers aren't giving up on flood-resistant crops. They hope additional studies will reveal new strategies for boosting genetic defenses against flooding in grains and other staple crops.