A bifurcating pathway directs abscisic acid effects on stomatal closure and opening in Arabidopsis.
Terrestrial plants lose water primarily through stomata, pores on the leaves. The hormone abscisic acid (ABA) decreases water loss by regulating opening and closing of stomata. Here, we show that phospholipase Dalpha1 (PLDalpha1) mediates the ABA effects on stomata through interaction with a protein phosphatase 2C (PP2C) and a heterotrimeric GTP-binding protein (G protein) in Arabidopsis. PLDalpha1-produced phosphatidic acid (PA) binds to the ABI1 PP2C to signal ABA-promoted stomatal closure, whereas PLDalpha1 and PA interact with the Galpha subunit of heterotrimeric G protein to mediate ABA inhibition of stomatal opening. The results reveal a bifurcating signaling pathway that regulates plant water loss.
Mishra
Girish
G
Department of Biology, University of Missouri, St. Louis, MO 63121, USA, and Donald Danforth Plant Science Center, St. Louis, MO 63132, USA.
Zhang
Wenhua
W
Deng
Fan
F
Zhao
Jian
J
Wang
Xuemin
X
D000040:Abscisic Acid / Q000378:metabolism*; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003433:Crosses, Genetic; D044385:GTP-Binding Protein alpha Subunits / Q000378:metabolism; D009154:Mutation; D010712:Phosphatidic Acids / Q000378:metabolism; D010739:Phospholipase D / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000502:physiology*; D015398:Signal Transduction; D019076:Transgenes; D014867:Water / Q000378:metabolism
D029681:Arabidopsis Proteins; C429765:GPA1 protein, Arabidopsis; D044385:GTP-Binding Protein alpha Subunits; D010712:Phosphatidic Acids; D014867:Water; D000040:Abscisic Acid; C087434:ABI1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases; D010739:Phospholipase D