Zhu Wanting, Cao Sen, Huang Mengling, Li Pengyue, Ke Jingjing, Xu Ai, Lin Yang, Xie Jiatao, Cheng Jiasen, Fu Yanping, Jiang Daohong, Yu Xiao, Li Bo
National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
Hubei Hongshan Laboratory, Wuhan, Hubei 430070, China.
Sci Adv. 2025 May 30;11(22):eadu2840. doi: 10.1126/sciadv.adu2840.
Bacterial wilt caused by is a devastating plant disease. Exopolysaccharide (EPS), a major virulence factor of , elicits pattern-triggered immunity (PTI) in tomato, but the means by which EPS is recognized in the plant remain poorly understood. We found that tomato non-arginine-aspartate (non-RD) receptor kinase SlLYK4 mediates the perception of EPS and positively regulates resistance to bacterial wilt. The RD receptor kinases SlLYK1 and SlLYK13 are required for EPS-triggered immune responses and form complexes with SlLYK4. These receptor kinase complexes have dual functions in recognizing bacterial EPS and fungal chitin. Phosphorylation of serine-320 in the juxtamembrane domain of SlLYK4 is essential in EPS- and chitin-mediated signaling, whereas phosphorylation of serine-334 or serine-634 in the C-terminal domain is required for chitin or EPS signaling, respectively. Our results reveal the mechanism underlying EPS recognition in tomato and provide insight into how differential phosphorylation of receptor kinase regulates antibacterial and antifungal immunity.
由[病原菌名称缺失]引起的青枯病是一种具有毁灭性的植物病害。胞外多糖（EPS）是[病原菌名称缺失]的一种主要毒力因子，它能在番茄中引发模式触发免疫（PTI），但植物中EPS被识别的方式仍知之甚少。我们发现番茄非精氨酸-天冬氨酸（non-RD）受体激酶SlLYK4介导了对[病原菌名称缺失]EPS的感知，并正向调节对青枯病的抗性。RD受体激酶SlLYK1和SlLYK13是EPS触发的免疫反应所必需的，并与SlLYK4形成复合物。这些受体激酶复合物在识别细菌EPS和真菌几丁质方面具有双重功能。SlLYK4近膜结构域中丝氨酸-320的磷酸化在EPS和几丁质介导的信号传导中至关重要，而C末端结构域中丝氨酸-334或丝氨酸-634的磷酸化分别是几丁质或EPS信号传导所必需的。我们的结果揭示了番茄中EPS识别的潜在机制，并为受体激酶的差异磷酸化如何调节抗菌和抗真菌免疫提供了见解。
