四川大学生命科学学院张跃林教授团队研究出水杨酸受体转录调控的机制。该项研究成果发表在2026年9月16日出版的《自然》上。

水杨酸（SA）是一种激活植物防御反应的关键植物激素。在拟南芥中，NPR1（也称为NIM1）和NPR3/NPR4已被鉴定为负责感知SA的双重SA受体。然而，SA与NPR蛋白结合如何导致防御基因表达诱导的机制仍不清楚。在此，研究人员阐明了SA如何通过NPR1触发转录激活，并解除NPR3/NPR4介导的转录抑制。他们鉴定出Mediator复合体亚基15A（MED15A）作为连接NPR1与调控转录的Mediator复合体的桥梁。SA诱导NPR1与MED15A直接相互作用。结构和功能分析表明，NPR1与MED15A的结合对于NPR1介导的转录激活至关重要。同时，SA解除NPR3/NPR4介导的转录抑制。NIM1相互作用蛋白1（NIMIN1）与NPR3/NPR4和Topless（TPL）共抑制因子相互作用，将它们与多梳抑制复合物2（PRC2）连接，从而介导SA响应基因的H3K27三甲基化。SA抑制NPR3/NPR4与NIMIN1之间的相互作用，降低H3K27三甲基化水平，并增加靶基因的组蛋白乙酰化，从而解除NPR3/NPR4介导的抑制。该研究提供了SA介导防御基因激活的全面视角。这些发现为设计更有效的SA类似物作为农用化学品，以及通过操控SA感知和信号传导来工程化作物抗性奠定了基础。

附：英文原文

Title: Mechanisms of Transcriptional Regulation by Salicylic Acid Receptors

Author: Peng, Yujun, Tian, Hainan, Ming, Zhenhua, Sun, Tongjun, Yu, Jiuyang, Wu, Mingsong, Huang, Danyi, Zhang, Yihan, Zhong, Zhenhui, Li, Xin, Zhang, Yuelin

Issue&Volume: 2026-09-16

Abstract: Salicylic acid (SA) is a key phytohormone that activates plant defense responses 1-3. In Arabidopsis, NPR1 (also known as NIM1) and NPR3/NPR4 have been identified as dual SA receptors responsible for perceiving SA 4-6. However, the mechanisms of how SA binding to the NPR proteins leads to induction of defense gene expression remain unclear. Here, we elucidate how SA triggers transcriptional activation via NPR1 and relieves transcriptional repression mediated by NPR3/NPR4. We identified Mediator Complex Subunit 15A (MED15A) as a bridge between NPR1 and the Mediator complex governing transcription. SA induces direct interaction of NPR1 with MED15A. Structural and functional analysis showed that the binding of NPR1 to MED15A is essential for NPR1-mediated transcriptional activation. Meanwhile, SA relieves transcriptional repression mediated by NPR3/NPR4. NIM1-interacting 1 (NIMIN1) interacts with NPR3/NPR4 and the Topless (TPL) co-repressor, connecting them to Polycomb Repressive Complex 2 (PRC2) to mediate H3K27 trimethylation of SA-responsive genes. SA inhibits the interactions between NPR3/NPR4 and NIMIN1, reduces H3K27 trimethylation levels and increases histone acetylation of the target genes to release NPR3/NPR4-mediated repression. Our study offers a comprehensive view of SA-mediated defense gene activation. These findings lay a foundation for designing more effective SA analogs as agrochemicals and for engineering crop resistance by manipulating SA perception and signaling.

DOI: 10.1038/s41586-026-11123-0

Source: https://www.nature.com/articles/s41586-026-11123-0