Liang Di, Yang Dongyong, Li Tai, Zhu Zhe, Yan Bingxiao, He Yang, Li Xiaoyuan, Zhai Keran, Liu Jiyun, Kawano Yoji, Deng Yiwen, Wu Xu Na, Liu Junzhong, He Zuhua
CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
Sci Bull (Beijing). 2025 Mar 15;70(5):733-747. doi: 10.1016/j.scib.2024.12.007. Epub 2024 Dec 9.
Nucleotide-binding leucine-rich repeat (NLR) receptors mediate pathogen effector-triggered immunity (ETI) in plants, and a subclass of NLRs are hypothesized to function at the plasma membrane (PM). However, how NLR traffic and PM delivery are regulated during immune responses remains largely unknown. The rice NLR PigmR confers broad-spectrum resistance to the blast fungus Magnaporthe oryzae. Here, we report that a PRA (Prenylated Rab acceptor) protein, PIBP4 (PigmR-INTERACTING and BLAST RESISTANCE PROTEIN 4), interacts with both PigmR and the active form of the Rab GTPase, OsRab5a, thereby loads a portion of PigmR on trafficking vesicles that target to PM microdomains. Microdomain-localized PigmR interacts with and activates the small GTPase OsRac1, which triggers reactive oxygen species signaling and hypersensitive response, leading to immune responses against blast infection. Thus, our study discovers a previously unknown mechanism that deploys a PRA-Rab protein delivering hub to ensure ETI, linking the membrane trafficking machinery with NLR function and immune activation in plants.
核苷酸结合富含亮氨酸重复序列（NLR）受体介导植物中的病原体效应子触发免疫（ETI），并且推测NLR的一个亚类在质膜（PM）上发挥作用。然而，在免疫反应过程中NLR如何运输以及如何递送至质膜在很大程度上仍然未知。水稻NLR蛋白PigmR赋予对稻瘟病菌Magnaporthe oryzae的广谱抗性。在此，我们报道一种类异戊二烯化Rab受体蛋白PIBP4（PigmR相互作用和抗稻瘟病蛋白4），它与PigmR以及Rab GTP酶的活性形式OsRab5a相互作用，从而将一部分PigmR装载到靶向质膜微区的运输囊泡上。定位于微区的PigmR与小GTP酶OsRac1相互作用并激活它，后者触发活性氧信号传导和超敏反应，从而引发针对稻瘟病感染的免疫反应。因此，我们的研究发现了一种以前未知的机制，该机制利用一种类异戊二烯化Rab受体蛋白运输枢纽来确保ETI，将膜运输机制与植物中的NLR功能和免疫激活联系起来。
