Wan Bingliang, Lin Yongjun, Mou Tongmin
National Key Laboratory of Crop, Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, PR China.
FEBS Lett. 2007 Mar 20;581(6):1179-89. doi: 10.1016/j.febslet.2007.02.030. Epub 2007 Feb 26.
Ca(2+)-dependent protein kinases (CDPKs) play an essential role in plant Ca(2+)-mediated signal transduction. Twenty-nine CDPK genes have been identified in the rice genome through a complete search of genome and full-length cDNA databases. Eight of them were reported previously to be inducible by different stress stimuli. Sequence comparison revealed that all 29 CDPK genes (OsCPK1-29) contain multiple stress-responsive cis-elements in the promoter region (1kb) upstream of genes. Analysis of the information extracted from the Rice Expression Database indicates that 11 of the CDPK genes are regulated by chilling temperature, dehydration, salt, rice blast infection and chitin treatment. RT-PCR and RNA gel blot hybridization were performed in this study to detect the expression 19 of the CDPK genes. Twelve CDPK genes exhibited cultivar- and tissue-specific expression; four CDPK genes (OsCPK6, OsCPK13, OsCPK17 and OsCPK25) were induced by chilling temperature, dehydration and salt stresses in the rice seedlings. While OsCPK13 (OsCDPK7) was already known to be inducible by chilling temperature and high salt, this is the first report that the other three genes are stress-regulated. OsCPK6 and OsCPK25 are up-regulated by dehydration and heat shock, respectively, while OsCPK17 is down-regulated by chilling temperature, dehydration and high salt stresses. Based on this evidence, rice CDPK genes may be important components in the signal transduction pathways for stress responses. Findings from this research are important for further dissecting mechanisms of stress response and functions of CDPK genes in rice.
钙依赖蛋白激酶（CDPKs）在植物钙介导的信号转导中起关键作用。通过对基因组和全长cDNA数据库进行全面搜索，在水稻基因组中鉴定出了29个CDPK基因。其中8个基因先前已报道可被不同的胁迫刺激诱导。序列比较显示，所有29个CDPK基因（OsCPK1 - 29）在基因上游1kb的启动子区域均含有多个胁迫响应顺式元件。对从水稻表达数据库中提取的信息进行分析表明，11个CDPK基因受低温、脱水、盐胁迫、稻瘟病菌感染和几丁质处理的调控。本研究通过RT - PCR和RNA凝胶印迹杂交检测了19个CDPK基因的表达。12个CDPK基因表现出品种和组织特异性表达；4个CDPK基因（OsCPK6、OsCPK13、OsCPK17和OsCPK25）在水稻幼苗中受低温、脱水和盐胁迫诱导。虽然已知OsCPK13（OsCDPK7）可被低温和高盐诱导，但这是首次报道其他三个基因受胁迫调控。OsCPK6和OsCPK25分别在脱水和热激处理下上调，而OsCPK17在低温、脱水和高盐胁迫下下调。基于这些证据，水稻CDPK基因可能是胁迫响应信号转导途径中的重要组成部分。本研究结果对于进一步剖析水稻中胁迫响应机制和CDPK基因的功能具有重要意义。
