Specific functions for Mediator complex subunits from different modules in the transcriptional response of Arabidopsis thaliana to abiotic stress
Specific functions for Mediator complex subunits from different modules in the transcriptional response of Arabidopsis thaliana to abiotic stress
复制标题
不同模块的Mediator复合体亚基在拟南芥非生物胁迫转录响应中的特异功能
DOI：
10.1038/s41598-020-61758-w
复制
发表时间：
2020-03-19
影响因子：
4.6
通讯作者：
Bjorklund, Stefan
中科院分区：
文献类型：
--
作者：
Crawford, Tim;Karamat, Fazeelat;Bjorklund, Stefan
不利的环境条件不利于植物的生长发育。对非生物胁迫条件的适应涉及信号通路的激活，这通常通过转录因子网络导致基因表达的变化。中介体是一种高度保守的协同调节复合体，是真核生物转录机制的重要组成部分。一些中介体亚基与应激反应信号通路有关；然而，关于植物介质在非生物胁迫反应中的作用，我们仍然知之甚少。在这里，我们使用RNA-seq分析拟南芥对热、冷和盐胁迫条件的转录反应。我们确定了一组常见的非生物胁迫调控，并描述了参与其转录调控的tf的顺序和组合性质。此外，我们确定了介导亚基MED9、MED16、MED18和CDK8的应激特异性作用，以及将它们连接到不同应激信号通路的假定tf。我们的数据还表明，在同一基因位点上，Mediator的亚基或模块具有不同的作用模式，包括胁迫前MED16的协同抑制功能。这些结果阐明了植物对非生物胁迫的转录反应中一个鲜为人知但重要的角色，并确定了靶基因和机制，作为进一步生化表征的前奏。
Adverse environmental conditions are detrimental to plant growth and development. Acclimation to abiotic stress conditions involves activation of signaling pathways which often results in changes in gene expression via networks of transcription factors (TFs). Mediator is a highly conserved co-regulator complex and an essential component of the transcriptional machinery in eukaryotes. Some Mediator subunits have been implicated in stress-responsive signaling pathways; however, much remains unknown regarding the role of plant Mediator in abiotic stress responses. Here, we use RNA-seq to analyze the transcriptional response of Arabidopsis thaliana to heat, cold and salt stress conditions. We identify a set of common abiotic stress regulons and describe the sequential and combinatorial nature of TFs involved in their transcriptional regulation. Furthermore, we identify stress-specific roles for the Mediator subunits MED9, MED16, MED18 and CDK8, and putative TFs connecting them to different stress signaling pathways. Our data also indicate different modes of action for subunits or modules of Mediator at the same gene loci, including a co-repressor function for MED16 prior to stress. These results illuminate a poorly understood but important player in the transcriptional response of plants to abiotic stress and identify target genes and mechanisms as a prelude to further biochemical characterization.