The Arabidopsis Ca(2+) -dependent protein kinase CPK12 negatively regulates abscisic acid signaling in seed germination and post-germination growth.
The Arabidopsis Ca(2+) -dependent protein kinase CPK12 negatively regulates abscisic acid signaling in seed germination and post-germination growth.
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DOI：
10.1111/j.1469-8137.2011.03793.x
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发表时间：
2011-10
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影响因子：
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通讯作者：
Rui Zhao;Hai-Li Sun;Chao Mei;Xiao-Jing Wang;Lu Yan;Rui Liu;Xiao-Feng Zhang;Xiao-fang Wang
中科院分区：
文献类型：
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作者：
Rui Zhao;Hai-Li Sun;Chao Mei;Xiao-Jing Wang;Lu Yan;Rui Liu;Xiao-Feng Zhang;Xiao-fang Wang
Ca（2+）依赖性蛋白激酶（CDPK）被认为参与脱落酸（阿坝）信号传导，并且拟南芥CDPK超家族的几个成员已被鉴定为阿坝信号传导的正调节剂，但CDPK是否负调节阿坝信号传导仍然未知。·在这里，我们研究了拟南芥（Arabidopsis thaliana）CDPK，CPK 12在阿坝信号通路中的功能。·我们产生了拟南芥CPK 12-RNAi系，并观察到CPK 12的下调导致种子萌发和萌发后生长中的阿坝超敏性，并改变了一组ABA响应基因的表达。表达分析表明，CPK 12广泛表达，定位于细胞质和细胞核。生化分析表明，CPK 12与2C型蛋白磷酸酶ABI 2相互作用，磷酸化并刺激ABI 2，并磷酸化两个ABA应答转录因子（ABF 1和ABF 4）。我们的研究结果表明，拟南芥CPK 12是种子萌发和萌发后生长的ABA信号负调控因子，这表明CDPK家族的不同成员可能通过在阿坝信号转导中起正和负作用而构成一个调控回路。
• Ca(2+) -dependent protein kinase (CDPK) is believed to be involved in abscisic acid (ABA) signaling, and several members of the Arabidopsis CDPK superfamily have been identified as positive ABA signaling regulators, but it remains unknown if CDPK negatively regulates ABA signaling. • Here, we investigated the function of an Arabidopsis (Arabidopsis thaliana) CDPK, CPK12, in ABA signaling pathway. • We generated Arabidopsis CPK12-RNAi lines, and observed that downregulation of CPK12 resulted in ABA hypersensitivity in seed germination and post-germination growth, and altered expression of a set of ABA-responsive genes. Expression assay showed that CPK12 was ubiquitously expressed and localized to both cytosol and nucleus. Biochemical assays showed that CPK12 interacted with, phosphorylated and stimulated a type 2C protein phosphatase ABI2, and phosphorylated two ABA-responsive transcription factors (ABF1 and ABF4) in vitro. • Our findings show that the Arabidopsis CPK12 is a negative ABA-signaling regulator in seed germination and post-germination growth, suggesting that different members of the CDPK family may constitute a regulation loop by functioning positively and negatively in ABA signal transduction.