CDK8 is associated with RAP2.6 and SnRK2.6 and positively modulates abscisic acid signaling and drought response in Arabidopsis
CDK8 is associated with RAP2.6 and SnRK2.6 and positively modulates abscisic acid signaling and drought response in Arabidopsis
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CDK8 与 RAP2.6 和 SnRK2.6 相关，并正向调节拟南芥中的脱落酸信号传导和干旱反应
DOI：
10.1111/nph.16787
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Jian-Kang Zhu
中科院分区：
文献类型：
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作者：
Yingfang Zhu;Pengcheng Huang;Pengcheng Guo;Leelyn Chong;Gaobo Yu;Xiaoli Sun;Tao Hu;Yuan Li;Chuan-Chih Hsu;Kai Tang;Yun Zhou;Chunzhao Zhao;Wei Gao;W Andy Tao;Tesfaye Mengiste;Jian-Kang Zhu
CDK 8是介体复合物的关键亚基，介体复合物是一种大型多蛋白复合物，是保守的真核生物转录机制的基本部分。然而，CDK 8在植物非生物胁迫响应中的生物学功能还没有得到充分的研究，在此，我们证明了CDK 8在拟南芥中作为脱落酸（阿坝）信号传导和干旱响应途径中的一个关键调节因子。与野生型相比，cdk 8突变体对阿坝的敏感性降低，气孔开度受损，对干旱胁迫敏感。转录组学和染色质免疫沉淀分析表明，CDK 8可能通过促进RNA聚合酶II募集到其启动子中来正向调节几个阿坝应答基因的转录。我们发现，CDK 8和SnRK2.6都与ERF/AP 2转录因子RAP 2.6发生物理相互作用，RAP 2.6可以直接与具有GCC或DRE元件的RD 29 A和COLD-REGULATED 15 A（COR 15 A）的启动子结合，从而促进它们的表达。更重要的是，我们还发现CDK 8在阿坝诱导的RAP 2.6和RAP 2.6介导的阿坝响应基因上调中是必不可少的，这表明CDK 8可以将SnRK2.6介导的阿坝信号传导与RNA聚合酶II连接起来，从而促进对阿坝和干旱信号的即时转录响应。
CDK8 is a key subunit of Mediator complex, a large multiprotein complex that is a fundamental part of the conserved eukaryotic transcriptional machinery. However, the biological functions ofCDK8in plant abiotic stress responses remain largely unexplored.Here, we demonstratedCDK8as a critical regulator in the abscisic acid (ABA) signaling and drought response pathways inArabidopsis. Compared to wild‐type,cdk8mutants showed reduced sensitivity to ABA, impaired stomatal apertures and hypersensitivity to drought stress. Transcriptomic and chromatin immunoprecipitation analysis revealed thatCDK8positively regulates the transcription of several ABA‐responsive genes, probably through promoting the recruitment of RNA polymerase II to their promoters.We discovered that both CDK8 and SnRK2.6 interact physically with an ERF/AP2 transcription factor RAP2.6, which can directly bind to the promoters ofRD29AandCOLD‐REGULATED 15A(COR15A) with GCC or DRE elements, thereby promoting their expression. Importantly, we also showed thatCDK8is essential for the ABA‐induced expression ofRAP2.6andRAP2.6‐mediated upregulation of ABA‐responsive genes, indicating that CDK8 could link the SnRK2.6‐mediated ABA signaling to RNA polymerase II to promote immediate transcriptional response to ABA and drought signals.Overall, our data provide new insights into the roles of CDK8 in modulating ABA signaling and drought responses.