研究人员发现，在拟南芥（Arabidopsis thaliana）中，局部感染后，转录因子CCA1 HIKING EXPEDITION（CHE）的保守半胱氨酸残基在系统性组织中发生巯基硫醇化，这增强了其与水杨酸（SA）合成基因ISOCHORISMATE SYNTHASE1（ICS1）启动子的结合，从而增加了SA的产生。
此外，通过NADPH氧化酶产生的过氧化氢（H2O2）是根据浓度依赖性巯基硫醇化CHE的移动信号。SA和先前报道的信号分子，如N-羟基哌啶酸（NHP）的积累，随后形成一个信号放大环路，从而建立SAR。
据悉，在植物中，局部感染可通过增加SA的产生引发系统获得性抗性（SAR）。多年来，关于移动信号的身份及其引发SAR时系统性SA合成的直接传导机制一直存在争议。
附：英文原文
Title: H2O2 sulfenylates CHE, linking local infection to the establishment of systemic acquired resistance
Author: Lijun Cao, Sargis Karapetyan, Heejin Yoo, Tianyuan Chen, Musoki Mwimba, Xing Zhang, Xinnian Dong
Issue&Volume: 2024-09-13
Abstract: In plants, a local infection can lead to systemic acquired resistance (SAR) through increased production of salicylic acid (SA). For many years, the identity of the mobile signal and its direct transduction mechanism for systemic SA synthesis in initiating SAR have been debated. We found that in Arabidopsis thaliana, after a local infection, the conserved cysteine residue of the transcription factor CCA1 HIKING EXPEDITION (CHE) undergoes sulfenylation in systemic tissues, which enhances its binding to the promoter of the SA-synthesis gene ISOCHORISMATE SYNTHASE1 (ICS1) and increases SA production. Furthermore, hydrogen peroxide (H2O2) produced through NADPH oxidases is the mobile signal that sulfenylates CHE in a concentration-dependent manner. Accumulation of SA and the previously reported signal molecules, such as N-hydroxypipecolic acid (NHP), then form a signal amplification loop to establish SAR.
DOI: adj7249
Source: https://www.science.org/doi/10.1126/science.adj7249