Yu Bo, Wu Qi, Li Xingxing, Zeng Rongfeng, Min Qian, Huang Junli
Key Laboratory of Biorheological Science and Technology of Ministry of Education, Bioengineering College of Chongqing University, 174 Shazheng Street, Chongqing, China.
New Phytol. 2022 Feb;233(3):1238-1256. doi: 10.1111/nph.17859. Epub 2021 Dec 3.
Recent studies have revealed the physiological roles of glutamate receptor-like channels (GLRs) in Arabidopsis; however, the functions of GLRs in rice remain largely unknown. Here, we show that knockout of OsGLR3.4 in rice leads to brassinosteroid (BR)-regulated growth defects and reduced BR sensitivity. Electrophoretic mobility shift assays and transient transactivation assays indicated that OsGLR3.4 is the downstream target of OsBZR1. Further, agonist profile assays showed that multiple amino acids can trigger transient Ca influx in an OsGLR3.4-dependent manner, indicating that OsGLR3.4 is a Ca -permeable channel. Meanwhile, the study of internode cells demonstrated that OsGLR3.4-mediated Ca flux is required for actin filament organization and vesicle trafficking. Following root injury, the triggering of both slow wave potentials (SWPs) in leaves and the jasmonic acid (JA) response are impaired in osglr3.4 mutants, indicating that OsGLR3.4 is required for root-to-shoot systemic wound signaling in rice. Brassinosteroid treatment enhanced SWPs and OsJAZ8 expression in root-wounded plants, suggesting that BR signaling synergistically regulates the OsGLR3.4-mediated systemic wound response. In summary, this article describes a mechanism of OsGLR3.4-mediated cell elongation and long-distance systemic wound signaling in plants and provides new insights into the contribution of GLRs to plant growth and responses to mechanical wounding.
最近的研究揭示了拟南芥中谷氨酸受体样通道（GLRs）的生理作用；然而，GLRs在水稻中的功能仍 largely未知。在这里，我们表明水稻中OsGLR3.4的敲除导致油菜素内酯（BR）调节的生长缺陷和BR敏感性降低。电泳迁移率变动分析和瞬时反式激活分析表明OsGLR3.4是OsBZR1的下游靶标。此外，激动剂谱分析表明多种氨基酸可以以OsGLR3.4依赖的方式触发瞬时Ca内流，表明OsGLR3.4是一个Ca可渗透通道。同时，对节间细胞的研究表明，肌动蛋白丝组织和囊泡运输需要OsGLR3.4介导的Ca通量。根受伤后，osglr3.4突变体中叶片的慢波电位（SWPs）和茉莉酸（JA）反应的触发均受损，表明OsGLR3.4是水稻根到茎系统伤口信号传导所必需的。油菜素内酯处理增强了根受伤植物中的SWPs和OsJAZ8表达，表明BR信号协同调节OsGLR3.4介导的系统伤口反应。总之，本文描述了OsGLR3.4介导的植物细胞伸长和长距离系统伤口信号传导的机制，并为GLRs对植物生长和对机械损伤的反应的贡献提供了新的见解。
