Involvement of ABA- and H2O2-dependent cytosolic glucose-6-phosphate dehydrogenase in maintaining redox homeostasis in soybean roots under drought stress.
The roles of abscisic acid (ABA) and hydrogen peroxide (H2O2) in inducing glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) activity and the possible roles of G6PDH in regulating ascorbate-glutathione (AsA-GSH) cycle were investigated in soybean (Glycine max L.) roots under drought stress. Drought caused a marked increase of the total and cytosolic G6PDH activities and triggered a rapid ABA and H2O2 accumulation in soybean roots. Exogenous ABA or H2O2 treatment elevated the total and cytosolic G6PDH activities, whereas suppressing ABA or H2O2 production inhibited the drought-induced increase in total and cytosolic G6PDH activities, suggesting that ABA and H2O2 are required for drought-induced increase of total G6PDH activity, namely cytosolic G6PDH activity. Furthermore, ABA induced H2O2 production by stimulating NADPH oxidase activity under drought stress. Moreover, drought significantly increased the contents of AsA and GSH and the activities of key enzymes in AsA-GSH cycle, while application of G6PDH inhibitor to seedlings significantly reduced the above effect induced by drought. Taken together, these results indicate that H2O2 acting as a downstream signaling molecule of ABA mediates drought-induced increase in cytosolic G6PDH activity, and that enhanced cytosolic G6PDH activity maintains cellular redox homeostasis by regulating AsA-GSH cycle in soybean roots.
College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, PR China. Electronic address: hhwang04@163.com.
Huahua
H
Wang
College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, PR China.
Lidan
L
Yang
College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, PR China.
Yan
Y
Li
College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, PR China.
Junjie
J
Hou
College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, PR China.
Junjun
J
Huang
College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, PR China.
Weihong
W
Liang
D000040:Abscisic Acid / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology*; D055864:Droughts; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D019255:NADPH Oxidases / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology*; D013025:Glycine max / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects*
D000975:Antioxidants; D004791:Enzyme Inhibitors; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D019255:NADPH Oxidases; D005978:Glutathione; D001205:Ascorbic Acid
Abscisic acid; Ascorbate-glutathione cycle; Drought resistance; Glucose-6-phosphate dehydrogenase; Hydrogen peroxide; Oxidative damage