The evolutionarily conserved Polycomb repressive complexes (PRC) mediate genome-wide transcriptional silencing and regulate a plethora of development, as well as environmental responses in multicellular organisms. The PRC2-catalyzed trimethylation of lysine 27 on histone H3 (H3K27me3) is recognized by reader-effector modules of PRC1 to implement gene repression. Here, we report that the Arabidopsis (Arabidopsis thaliana) H3K27me3 effector EMBRYONIC FLOWER 1 (EMF1) interacts with and constrains the R2R3 DNA binding transcription factor MYB26 by a eudicot-conserved motif in the stamen. MYB26 activates the transcription of two NAC domain genes, NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1) and NST2, whose encoded proteins mediate anther secondary cell thickening in jasmonate (JA)-regulated stamen maturation. In this process, the transcriptional activity of MYB26 is negatively modulated by the JAZ-PRC repressive complex to precisely regulate the expression of NST1 and NST2. Disruption of EMF1 repression stimulates MYB26, leading to the excessive transcription of the two NAC genes and male sterility. Our results reveal a novel mechanism in polycomb-mediated gene silencing and illustrate that the plant Polycomb complex regulates stamen development by preventing the hypersensitivity of JA responses in male reproduction.

中文翻译：

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EMBRYONIC FLOWER 1 通过抑制茉莉酸途径下游转录因子 MYB26 来调节雄性生殖


进化上保守的多梳抑制复合物 （PRC） 介导全基因组转录沉默并调节多细胞生物中的大量发育和环境反应。PRC2 催化的组蛋白 H3 上赖氨酸 27 的三甲基化 （H3K27me3） 被 PRC1 的读取效应模块识别以实现基因抑制。在这里，我们报道了拟南芥 （Arabidopsis thaliana） H3K27me3 效应子 EMBRYONIC FLOWER 1 （EMF1） 与雄蕊中双子叶细胞保守基序相互作用并限制 R2R3 DNA 结合转录因子 MYB26。MYB26 激活两个 NAC 结构域基因的转录，即 NAC 次生壁增厚促进FACTOR1 （NST1） 和 NST2，其编码的蛋白介导茉莉酸 （JA） 调节雄蕊成熟的花药次生细胞增厚。在此过程中，MYB26 的转录活性受到 JAZ-PRC 抑制复合物的负调控，以精确调节 NST1 和 NST2 的表达。EMF1 抑制的破坏刺激 MYB26，导致两个 NAC 基因的过度转录和男性不育。我们的结果揭示了多梳介导的基因沉默的新机制，并表明植物多梳复合物通过阻止雄性生殖中 JA 反应的超敏反应来调节雄蕊发育。