title: Arabidopsis CALCIUM-DEPENDENT PROTEIN KINASE8 and CATALASE3 Function in Abscisic Acid-Mediated Signaling and H2O2 Homeostasis in Stomatal Guard Cells under Drought Stress.
abstract: Drought is a major threat to plant growth and crop productivity. Calcium-dependent protein kinases (CDPKs, CPKs) are believed to play important roles in plant responses to drought stress. Here, we report that Arabidopsis thaliana CPK8 functions in abscisic acid (ABA)- and Ca(2+)-mediated plant responses to drought stress. The cpk8 mutant was more sensitive to drought stress than wild-type plants, while the transgenic plants overexpressing CPK8 showed enhanced tolerance to drought stress compared with wild-type plants. ABA-, H2O2-, and Ca(2+)-induced stomatal closing were impaired in cpk8 mutants. Arabidopsis CATALASE3 (CAT3) was identified as a CPK8-interacting protein, confirmed by yeast two-hybrid, coimmunoprecipitation, and bimolecular fluorescence complementation assays. CPK8 can phosphorylate CAT3 at Ser-261 and regulate its activity. Both cpk8 and cat3 plants showed lower catalase activity and higher accumulation of H2O2 compared with wild-type plants. The cat3 mutant displayed a similar drought stress-sensitive phenotype as cpk8 mutant. Moreover, ABA and Ca(2+) inhibition of inward K(+) currents were diminished in guard cells of cpk8 and cat3 mutants. Together, these results demonstrated that CPK8 functions in ABA-mediated stomatal regulation in responses to drought stress through regulation of CAT3 activity.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Jun-Jie
authors.identifier: http://orcid.org/0000-0002-4824-400X
authors.initials: JJ
authors.lastname: Zou
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Xi-Dong
authors.identifier: http://orcid.org/0000-0002-0077-4466
authors.initials: XD
authors.lastname: Li
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Disna
authors.identifier: http://orcid.org/0000-0003-3176-6888
authors.initials: D
authors.lastname: Ratnasekera
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Cun
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Wen-Xin
authors.identifier: http://orcid.org/0000-0003-0583-9510
authors.initials: WX
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Lian-Fen
authors.identifier: http://orcid.org/0000-0001-5497-5768
authors.initials: LF
authors.lastname: Song
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China.
authors.forename: Wen-Zheng
authors.initials: WZ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Plant Gene Research Centre (Beijing), China Agricultural University, Beijing 100193, China whwu@cau.edu.cn.
authors.forename: Wei-Hua
authors.identifier: http://orcid.org/0000-0002-0642-5523
authors.initials: WH
authors.lastname: Wu
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D056850:Cyclin-Dependent Kinase 8 / Q000235:genetics / Q000378:metabolism*; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D006861:Hydrogen Peroxide / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D054046:Plant Stomata / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D000040:Abscisic Acid; D029681:Arabidopsis Proteins; D002118:Calcium; D002374:Catalase; D056850:Cyclin-Dependent Kinase 8; D006861:Hydrogen Peroxide; D010937:Plant Growth Regulators; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C490323:CAT3 protein, Arabidopsis; C522174:AT5G63610 protein, Arabidopsis