植物部署细胞表面和细胞内受体以检测病原体攻击并触发先天免疫应答。在宿主细胞内,核苷酸结合/富含亮氨酸的重复(NLR)蛋白家族充当病原体传感器或免疫防御输出和细胞死亡的下游介质,预防疾病。NLR介导的免疫的已建立的遗传基础揭示了植物用于对抗快速进化的微生物病原体的各种策略。NLR激活和信号传递到控制免疫执行的成分的分子机制尚不清楚。这里,我们回顾了最近对植物NLR传感器和信号功能的蛋白质结构和生化见解。当放在一起,数据显示了不同的NLR家族,无论是传感器还是信号传感器,融合基于核苷酸的第二信使和细胞钙以赋予免疫力。尽管植物中病原体激活的NLR参与植物特异性机制来促进防御,与哺乳动物NLR免疫受体对应物的比较突出了NLR免疫的一些共同工作原理。
Plants deploy cell-surface and intracellular receptors to detect pathogen attack and trigger innate immune responses. Inside host cells, families of nucleotide-binding/leucine-rich repeat (NLR) proteins serve as pathogen sensors or downstream mediators of immune defence outputs and cell death, which prevent disease. Established genetic underpinnings of NLR-mediated immunity revealed various strategies plants adopt to combat rapidly evolving microbial pathogens. The molecular mechanisms of NLR activation and signal transmission to components controlling immunity execution were less clear. Here, we review recent protein structural and biochemical insights to plant NLR sensor and signalling functions. When put together, the data show how different NLR families, whether sensors or signal transducers, converge on nucleotide-based second messengers and cellular calcium to confer immunity. Although pathogen-activated NLRs in plants engage plant-specific machineries to promote defence, comparisons with mammalian NLR immune receptor counterparts highlight some shared working principles for NLR immunity across kingdoms.