Arabidopsis calcium-dependent protein kinase CPK28 is potentially involved in the response to osmotic stress

作     者：Anli Gao Qingyang Wu Yu Zhang Yuchen Miao Chunpeng Song 

作者机构：State Key Laboratory of Cotton BiologyInstitute of Plant Stress BiologyCollege of Life SciencesHenan University 

出 版 物：《Chinese Science Bulletin》 (科学通报(英文版))

年 卷 期：2014年第59卷第11期

页      面：1113-1122页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 

基　　金：supported by the National Genetically Modified Organisms Breeding Major Projects(2011ZX08009-002) 

主　　题：钙依赖蛋白激酶 渗透胁迫 拟南芥 聚合酶链反应 CDPK 应激反应 转录水平 非生物胁迫 

摘      要：As calcium sensors, plant calcium-dependent protein kinases(CDPKs) play important roles in plants responses to various abiotic stresses. Here, we report the functional characterization of CPK28, a member of the CDPK family in Arabidopsis, in response to osmotic *** cpk28 mutant, a loss-of-function mutant, exhibited an NaCl- and mannitol-sensitive phenotype in green cotyledons, while CPK28-overexpressing plants displayed stronger tolerance to NaCl and mannitol stresses than wildtype plants. Reverse transcriptase-polymerase chain reaction and beta-glucuronidase staining assays showed that NaCl and mannitol stresses induced CPK28. CPK28-overexpressing lines accumulated significantly more proline relative to wild-type plants and mutant plants under NaCl and mannitol stresses. Transient expression of CPK28-GFP in mesophyll cell protoplasts, as well as stable transgenic lines expressing CPK28-GFP, showed that CPK28 was localized in the plasma membrane. Expression levels of known stress-responsive genes were not significantly altered in the null mutant and overexpression lines,suggesting that CPK28 possibly mediated the stress response via the regulation of target proteins rather than via regulation at the level of transcription. Meanwhile, CPK28could autophosphorylate. Taken together, these data demonstrated that CPK28, a potential positive regulator, is involved in the response to osmotic stress in Arabidopsis.