New study of water-saving plants advances efforts to develop drought-resistant crops

As part of an effort to develop drought-resistant food and bioenergy crops, scientists at the Department of Energy’s Oak Ridge National Laboratory have uncovered the genetic and metabolic mechanisms that allow certain plants to conserve water and thrive in semi-arid climates.
Semi-arid plants such as agave have adapted to survive in areas with little rainfall by developing a specialized mode of photosynthesis called crassulacean acid metabolism, or CAM.
ORNL scientists are studying the unique metabolic mechanisms that allow CAM plants to conserve water, with the goal of introducing water-saving traits into bioenergy and food crops.
The results of the team’s latest study, which focuses on agave, are published in Nature Plants.
To gain a comprehensive view of the complex CAM system, the team used ORNL’s mass spectrometry to compare the molecular traits of agave with a control plant, Arabidopsis, which uses a more common photosynthetic process.
Their study revealed that the timing of daytime versus nighttime stomatal activity varied significantly between agave and Arabidopsis.
The research also pinpointed which genetic and metabolic mechanisms signal CAM plants to open and close their stomata.
Understanding the timing of these signals will be key to transferring CAM processes into crops such as rice, corn, poplar and switchgrass.
"The transfer of CAM molecular machinery into energy crops would facilitate their deployment onto marginal lands and would simultaneously reduce competition with food crops."
Journal Reference: Paul E. Abraham, Hengfu Yin, Anne M. Borland, Deborah Weighill, Sung Don Lim, Henrique Cestari De Paoli, Nancy Engle, Piet C. Jones, Ryan Agh, David J. Weston, Stan D. Wullschleger, Timothy Tschaplinski, Daniel Jacobson, John C. Cushman, Robert L. Hettich, Gerald A. Tuskan, Xiaohan Yang.

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