Overexpression of AtABCG25 enhances the abscisic acid signal in guard cells and improves plant water use efficiency.
In addition to improving drought tolerance, improvement of water use efficiency is a major challenge in plant physiology. Due to their trade-off relationships, it is generally considered that achieving stress tolerance is incompatible with maintaining stable growth. Abscisic acid (ABA) is a key phytohormone that regulates the balance between intrinsic growth and environmental responses. Previously, we identified AtABCG25 as a cell-membrane ABA transporter that export ABA from the inside to the outside of cells. AtABCG25-overexpressing plants showed a lower transpiration phenotype without any growth retardation. Here, we dissected this useful trait using precise phenotyping approaches. AtABCG25 overexpression stimulated a local ABA response in guard cells. Furthermore, AtABCG25 overexpression enhanced drought tolerance, probably resulting from maintenance of water contents over the common threshold for survival after drought stress treatment. Finally, we observed enhanced water use efficiency by overexpression of AtABCG25, in addition to drought tolerance. These results were consistent with the function of AtABCG25 as an ABA efflux transporter. This unique trait may be generally useful for improving the water use efficiency and drought tolerance of plants.
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan.
Takashi
T
Kuromori
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Tsukuba, Ibaraki 305-0074, Japan.
Miki
M
Fujita
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Tsukuba, Ibaraki 305-0074, Japan.
Kaoru
K
Urano
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Tsukuba, Ibaraki 305-0074, Japan.
Takanari
T
Tanabata
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan.
Eriko
E
Sugimoto
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan; Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Tsukuba, Ibaraki 305-0074, Japan. Electronic address: kazuo.shinozaki@riken.jp.
Kazuo
K
Shinozaki
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003247:Conservation of Natural Resources; D018506:Gene Expression Regulation, Plant; D054046:Plant Stomata / Q000502:physiology; D015398:Signal Transduction; D014867:Water / Q000378:metabolism*
C000606829:ABCG25 protein, Arabidopsis; D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D014867:Water; D000040:Abscisic Acid
ATP-binding cassette (ABC) transporter; Abscisic acid; Drought tolerance; Transpiration; Water use efficiency