Principles and characteristics of the Arabidopsis WRKY regulatory network during early MAMP-triggered immunity
Principles and characteristics of the Arabidopsis WRKY regulatory network during early MAMP-triggered immunity
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DOI：
10.1111/tpj.14043
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发表时间：
2018-11-01
期刊：
影响因子：
7.2
通讯作者：
Somssich, Imre E.
中科院分区：
文献类型：
--
作者：
Birkenbihl, Rainer P.;Kracher, Barbara;Somssich, Imre E.
在微生物相关分子模式触发的免疫过程中，5000多个拟南芥基因的表达发生了显著变化，问题出现了，如何以安全和可靠的方式调节如此巨大的转录组重新编程？对于WRKY转录因子(TF)来说，它们是许多防御反应的重要调节因子，它们似乎是在一个复杂的调节子网络中发挥作用，而不是以线性方式发挥作用，后者更容易受到病原体衍生的效应器或突变导致的基因功能丧失的影响。在这项研究中，我们使用了RNA-SEQ、质谱仪和染色质免疫沉淀-SEQ来寻找证据和揭示这一网络的原理和特征。在flg22处理后，我们可以区分两组WRKY基因：结构性表达的和诱导表达的WRKY基因。在诱导之前，诱导的WRKY基因似乎主要由结构性表达的WRKY因子维持在抑制状态，而这些因子本身似乎受到非WRKY转录因子的调控。诱导后的WRKY迅速与诱导的WRKY基因启动子结合，并通过自身和交叉调控建立起调控网络。这种由flg22诱导的网络的维护似乎非常稳健，因为移除三个关键的WRKY因子可以由其他WRKY家族成员在物理和功能上进行补偿。
During microbe-associated molecular pattern-triggered immunity more than 5000 Arabidopsis genes are significantly altered in their expression, and the question arises, how such an enormous reprogramming of the transcriptome can be regulated in a safe and robust manner? For the WRKY transcription factors (TFs), which are important regulators of numerous defense responses, it appears that they act in a complex regulatory sub-network rather than in a linear fashion, which would be much more vulnerable to gene function loss either by pathogen-derived effectors or by mutations. In this study we employed RNA-seq, mass spectrometry and chromatin immunoprecipitation-seq to find evidence for and uncover principles and characteristics of this network. Upon flg22-treatment, one can distinguish between two sets of WRKY genes: constitutively expressed and induced WRKY genes. Prior to elicitation the induced WRKY genes appear to be maintained in a repressed state mainly by the constitutively expressed WRKY factors, which themselves appear to be regulated by non-WRKY TFs. Upon elicitation, induced WRKYs rapidly bind to induced WRKY gene promoters and by auto- and cross-regulation build up the regulatory network. Maintenance of this flg22-induced network appears highly robust as removal of three key WRKY factors can be physically and functionally compensated for by other WRKY family members.