Two calcium-dependent protein kinases, CPK4 and CPK11, regulate abscisic acid signal transduction in Arabidopsis
Two calcium-dependent protein kinases, CPK4 and CPK11, regulate abscisic acid signal transduction in Arabidopsis
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拟南芥中两种钙依赖性蛋白激酶 CPK4 和 CPK11 调节脱落酸信号转导
DOI：
10.1105/tpc.107.050666
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发表时间：
2007-10-01
期刊：
影响因子：
11.6
通讯作者：
Zhang, Da-Peng
中科院分区：
文献类型：
--
作者：
Zhu, Sai-Yong;Yu, Xiang-Chun;Zhang, Da-Peng
许多生物化学方法显示钙依赖蛋白激酶（CDPKs）在脱落酸（阿坝）信号转导中的功能，但在整株水平上将已定义的CDPK基因与ABA调节的生物学功能联系起来的分子遗传学证据一直缺乏。在这里，我们报告阿坝刺激两个同源的CDPK在拟南芥，CPK 4和CPK 11。CPK 4和CPK 11的功能丧失突变导致了种子萌发、幼苗生长和气孔运动中ABA不敏感的多效表型，并导致种子萌发中的盐不敏感性和幼苗对盐胁迫的耐受性降低。两个CDPK基因的双突变体比单突变体具有更强的阿坝和盐响应表型。CPK 4-或CPK 11-过表达的植物通常表现出相反的ABA相关的表型相对于那些功能丧失的突变体。在功能丧失突变体和过表达株系中，许多ABA应答基因的表达水平发生了改变。CPK 4和CPK 11激酶在体外均磷酸化ABA响应性转录因子ABF 1和ABF 4，表明这两种激酶可能通过这些转录因子调节阿坝信号传导。这些数据提供了植物遗传学证据，表明在整个植物水平上，CDPK/钙参与阿坝信号传导，并表明CPK 4和CPK 11是CDPK/钙介导的阿坝信号传导途径中的两个重要的正调控因子。
Many biochemical approaches show functions of calcium-dependent protein kinases (CDPKs) in abscisic acid (ABA) signal transduction, but molecular genetic evidence linking defined CDPK genes with ABA-regulated biological functions at the whole-plant level has been lacking. Here, we report that ABA stimulated two homologousCDPKsin Arabidopsis thaliana, CPK4 and CPK11. Loss-of-function mutations of CPK4 and CPK11 resulted in pleiotropic ABA-insensitive phenotypes in seed germination, seedling growth, and stomatal movement and led to salt insensitivity in seed germination and decreased tolerance of seedlings to salt stress. Double mutants of the two CDPK genes had stronger ABA- and salt-responsive phenotypes than the single mutants. CPK4- or CPK11- overexpressing plants generally showed inverse ABA-related phenotypes relative to those of the loss-of-function mutants. Expression levels of many ABA-responsive genes were altered in the loss-of-function mutants and overexpression lines. The CPK4 and CPK11 kinases both phosphorylated two ABA-responsive transcription factors, ABF1 and ABF4, in vitro, suggesting that the two kinases may regulate ABA signaling through these transcription factors. These data provide in planta genetic evidence for the involvement of CDPK/calcium in ABA signaling at the whole-plant level and show that CPK4 and CPK11 are two important positive regulators in CDPK/calcium-mediated ABA signaling pathways.