Genetic mutation helps plants use less water without biomass loss

WASHINGTON - Purdue University researchers have made a discovery that could reduce the amount of water required for growing plants and help plants survive and thrive in adverse conditions.

They have found a genetic mutation that allows a plant to better endure drought without losing biomass.

Plants can naturally control the opening and closing of stomata, pores that take in carbon dioxide and release water. During drought conditions, a plant might close its stomata to conserve water. By doing so, however, the plant also reduces the amount of carbon dioxide it can take in, which limits photosynthesis and growth.

Mike Mickelbart, an assistant professor of horticulture; Mike Hasegawa, a professor of horticulture; and Chal Yul Yoo, a horticulture graduate student, found that a genetic mutation in the research plant Arabidopsis thaliana reduces the number of stomata. But instead of limiting carbon dioxide intake, the gene creates a beneficial equilibrium.

Mickelbart and Yoo used an infrared gas analyzer to determine the amount of carbon dioxide taken in and water lost in the Arabidopsis mutant.

Analysis showed that the plant, which has a mutant form of the gene GTL1, did not reduce carbon dioxide intake but did have a 20 percent reduction in transpiration. The plant had the same biomass as a wild type of Arabidopsis when its shoot dry weight was measured.

“The decrease in transpiration leads to increased drought tolerance in the mutant plants,” Yoo said.

“They will hold more water in their leaves during drought stress.”

The results have been published in the online version of the journal The Plant Cell. (ANI)