摘要
Ca^2＋ and calmodulin （CAM） have been shown to play an important role in abscisic acid （ABA）-induced anti- oxidant defense. However, it is unknown whether Ca^2＋/CaM-dependent protein kinase （CCaMK） is involved in the pro- cess. In the present study, the role of rice CCaMK, OsDMI3, in ABA-induced antioxidant defense was investigated in leaves of rice （Oryza sativa） plants. Treatments with ABA, H2O2, and polyethylene glycol （PEG） induced the expression of OsDMI3 and the activity of OsDMI3, and H2O2 is required for the ABA-induced increases in the expression and the activity of OsDMI3 under water stress. Subcellular localization analysis showed that OsDMI3 is located in the nucleus, the cytoplasm, and the plasma membrane. The analysis of the transient expression of OsDMI3 in rice protoplasts and the RNA interference （RNAi） silencing of OsDMI3 in rice protoplasts showed that OsDMI3 is required for ABA-induced increases in the expression and the activities of superoxide dismutase （SOD） and catalase （CAT）. Further, the oxidative damage induced by higher concentrations of PEG and H202 was aggravated in the mutant of OsDMI3. Moreover, the analysis of the RNAi silencing of OsDMI3 in protoplasts and the mutant of OsDMI3 showed that higher levels of H2O2 accumulation require OsDMI3 activation in ABA signaling, but the initial H2O2 production induced by ABA is not depend- ent on the activation of OsDMI3 in leaves of rice plants. Our data reveal that OsDMI3 is an important component in ABA-induced antioxidant defense in rice.
Ca^2＋ and calmodulin （CAM） have been shown to play an important role in abscisic acid （ABA）-induced anti- oxidant defense. However, it is unknown whether Ca^2＋/CaM-dependent protein kinase （CCaMK） is involved in the pro- cess. In the present study, the role of rice CCaMK, OsDMI3, in ABA-induced antioxidant defense was investigated in leaves of rice （Oryza sativa） plants. Treatments with ABA, H2O2, and polyethylene glycol （PEG） induced the expression of OsDMI3 and the activity of OsDMI3, and H2O2 is required for the ABA-induced increases in the expression and the activity of OsDMI3 under water stress. Subcellular localization analysis showed that OsDMI3 is located in the nucleus, the cytoplasm, and the plasma membrane. The analysis of the transient expression of OsDMI3 in rice protoplasts and the RNA interference （RNAi） silencing of OsDMI3 in rice protoplasts showed that OsDMI3 is required for ABA-induced increases in the expression and the activities of superoxide dismutase （SOD） and catalase （CAT）. Further, the oxidative damage induced by higher concentrations of PEG and H202 was aggravated in the mutant of OsDMI3. Moreover, the analysis of the RNAi silencing of OsDMI3 in protoplasts and the mutant of OsDMI3 showed that higher levels of H2O2 accumulation require OsDMI3 activation in ABA signaling, but the initial H2O2 production induced by ABA is not depend- ent on the activation of OsDMI3 in leaves of rice plants. Our data reveal that OsDMI3 is an important component in ABA-induced antioxidant defense in rice.
基金
the National Basic Research Program of China，the National Natural Science Foundation of China，the Fundamental Research Funds for the Central Universities，the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,the Natural Science Foundation of Jiangsu Province，the Research Fund for the Doctoral Program of Higher Education of China，the Program for New Century Excellent Talents in University，the grant from the Education Department of Jiangsu
