通过筛选rod1突变体的抑制子，研究人员发现ROD1通过监控经典免疫通路的激活来调节免疫稳态。OsTIR（仅含TIR结构域的蛋白质）、OsEDS1（增强病害易感性1）、OsPAD4（植物抗生素缺失4）和OsADR1（激活病害抗性1）中的突变都消除了rod1植物的增强病害抗性。
OsTIR催化第二信使2′-(5′′-磷酸核糖基)-5′-腺苷单磷酸（pRib-AMP）和二磷酸（pRib-ADP）的生成，这些信使触发了OsEDS1-OsPAD4-OsADR1（EPA）免疫复合物的形成。ROD1与OsTIR相互作用并抑制其酶活性，而ROD1突变会导致EPA复合物的持续激活。
因此，研究人员揭示了一个免疫网络，可精细调控水稻的免疫稳态和多病原抵抗。
研究人员表示，钙离子传感器ROD1是水稻免疫的主调控因子。
附：英文原文
Title: A canonical protein complex controls immune homeostasis and multipathogen resistance
Author: Yue Wu, Weiying Xu, Guoyan Zhao, Ziyao Lei, Kui Li, Jiyun Liu, Shijia Huang, Junli Wang, Xiangbin Zhong, Xin Yin, Yuandong Wang, Haochen Zhang, Yang He, Zian Ye, Yonggang Meng, Xiaoyu Chang, Hui Lin, Xin Wang, Yuanyuan Gao, Jijie Chai, Jane E. Parker, Yiwen Deng, Yu Zhang, Mingjun Gao, Zuhua He
Issue&Volume: 2024-11-07
Abstract: The Ca2+ sensor, ROD1, is a master regulator of immunity in rice. By screening suppressors of rod1 mutants, we show that ROD1 governs immune homeostasis by surveilling the activation of a canonical immune pathway. Mutations in OsTIR (TIR-only protein), OsEDS1 (Enhanced Disease Susceptibility 1), OsPAD4 (Phytoalexin Deficient 4), and OsADR1 (Activated Disease Resistance 1) all abolish enhanced disease resistance of rod1 plants. OsTIR catalyzes the production of second messengers 2′-(5′′-phosphoribosyl)-5′-adenosine monophosphate (pRib-AMP) and diphosphate (pRib-ADP), which trigger formation of an OsEDS1-OsPAD4-OsADR1 (EPA) immune complex. ROD1 interacts with OsTIR and inhibits its enzymatic activity while mutation of ROD1 leads to constitutive activation of the EPA complex. Thus, we unveil an immune network that fine-tunes immune homeostasis and multipathogen resistance in rice.
DOI: adr2138
Source: https://www.science.org/doi/10.1126/science.adr2138