Legumes evolved LysM receptors for recognition of rhizobial Nod factors and initiation of signalling pathways for nodule organogenesis and infection. Intracellularly hosted bacteria are supplied with carbon resources in exchange for fixed nitrogen. Nod factor recognition is crucial for initial signalling, but is reiterated in growing roots initiating novel symbiotic events, and in developing primordia until symbiosis is well-established. Understanding how this signalling coordinates the entire process from cellular to plant level is key for de novo engineering in non-legumes and for improved efficiency in legumes. Here we discuss how recent studies bring new insights into molecular determinants of specificity and sensitivity in Nod factor signalling in legumes, and present some of the unknowns and challenges for engineering.

豆类进化出 LysM 受体，用于识别根瘤菌 Nod 因子并启动用于根瘤器官发生和感染的信号通路。细胞内寄宿的细菌被提供碳资源以换取固定氮。点头因子识别对于初始信号传导至关重要，但在启动新共生事件的生长根和发展原基直至共生建立起来时重申。了解这种信号如何协调从细胞到植物水平的整个过程是de novo 的关键非豆类工程和提高豆类的效率。在这里，我们讨论了最近的研究如何为豆科植物 Nod 因子信号传导的特异性和敏感性的分子决定因素带来新见解，并提出一些工程的未知数和挑战。