Involvement of protein phosphorylation in water stress-induced antioxidant defense in maize leaves.
Using pharmacological and biochemical approaches, the role of protein phosphorylation and the interrelationship between water stress-enhanced kinase activity, antioxidant enzyme activity, hydrogen peroxide (H2O2) accumulation and endogenous abscisic acid in maize (Zea mays L.) leaves were investigated. Water-stress upregulated the activities of total protein phosphorylation and Ca2+-dependent protein kinase, and the upregulation was blocked in abscisic acid-deficient vp5 mutant. Furthermore, pretreatments with a nicotinamide adenine dinucleotide phosphate oxidase inhibitor and a scavenger of H2O2 significantly reduced the increased activities of total protein kinase and Ca2+-dependent protein kinase in maize leaves exposed to water stress. Pretreatments with different protein kinase inhibitors also reduced the water stress-induced H2O2 production and the water stress-enhanced activities of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase. The data suggest that protein phosphorylation and H2O2 generation are required for water stress-induced antioxidant defense in maize leaves and that crosstalk between protein phosphorylation and H2O2 generation may occur.
Xu
Shucheng
S
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Ding
Haidong
H
Su
Fengxia
F
Zhang
Aying
A
Jiang
Mingyi
M
D000040:Abscisic Acid / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D003681:Dehydration; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D010940:Plant Proteins / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D003313:Zea mays / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure
D000975:Antioxidants; D010940:Plant Proteins; D047428:Protein Kinase Inhibitors; D011092:Polyethylene Glycols; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D011494:Protein Kinases; D002118:Calcium