Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Taiwan.
Howard Hughes Medical Institute, New York University Langone School of Medicine, New York, NY, USA.
J Exp Bot. 2019 Feb 5;70(3):1033-1047. doi: 10.1093/jxb/ery414.
Recognition of microbe-associated molecular patterns (MAMPs) derived from invading pathogens by plant pattern recognition receptors (PRRs) initiates a subset of defense responses known as pattern-triggered immunity (PTI). Transcription factors (TFs) orchestrate the onset of PTI through complex signaling networks. Here, we characterized the function of ERF19, a member of the Arabidopsis thaliana ethylene response factor (ERF) family. ERF19 was found to act as a negative regulator of PTI against Botrytis cinerea and Pseudomonas syringae. Notably, overexpression of ERF19 increased plant susceptibility to these pathogens and repressed MAMP-induced PTI outputs. In contrast, expression of the chimeric dominant repressor ERF19-SRDX boosted PTI activation, conferred increased resistance to the fungus B. cinerea, and enhanced elf18-triggered immunity against bacteria. Consistent with a negative role for ERF19 in PTI, MAMP-mediated growth inhibition was weakened or augmented in lines overexpressing ERF19 or expressing ERF19-SRDX, respectively. Using biochemical and genetic approaches, we show that the transcriptional co-repressor Novel INteractor of JAZ (NINJA) associates with and represses the function of ERF19. Our work reveals ERF19 as a novel player in the mitigation of PTI, and highlights a potential role for NINJA in fine-tuning ERF19-mediated regulation of Arabidopsis innate immunity.
植物模式识别受体（PRRs）识别源自入侵病原体的微生物相关分子模式（MAMPs），从而引发被称为模式触发免疫（PTI）的防御反应。转录因子（TFs）通过复杂的信号网络来协调 PTI 的起始。在这里，我们研究了拟南芥乙烯响应因子（ERF）家族成员 ERF19 的功能。研究发现，ERF19 作为对 Botrytis cinerea 和 Pseudomonas syringae 的 PTI 的负调控因子发挥作用。值得注意的是，过表达 ERF19 会增加植物对这些病原体的易感性，并抑制 MAMP 诱导的 PTI 产物。相比之下，嵌合显性抑制剂 ERF19-SRDX 的表达增强了 PTI 的激活，赋予了对真菌 B. cinerea 的更高抗性，并增强了 elf18 触发的对细菌的免疫。与 ERF19 在 PTI 中的负作用一致，过表达 ERF19 或表达 ERF19-SRDX 的系中，MAMP 介导的生长抑制分别减弱或增强。通过生化和遗传方法，我们表明转录共抑制因子 Novel INteractor of JAZ（NINJA）与 ERF19 结合并抑制其功能。我们的工作揭示了 ERF19 是减轻 PTI 的新参与者，并强调了 NINJA 在微调 ERF19 介导的拟南芥先天免疫调节中的潜在作用。
