National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
University of the Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2024 Apr 26;15(1):3568. doi: 10.1038/s41467-024-47794-4.
Legume-rhizobia root-nodule symbioses involve the recognition of rhizobial Nod factor (NF) signals by NF receptors, triggering both nodule organogenesis and rhizobial infection. RinRK1 is induced by NF signaling and is essential for infection thread (IT) formation in Lotus japonicus. However, the precise mechanism underlying this process remains unknown. Here, we show that RinRK1 interacts with the extracellular domains of NF receptors (NFR1 and NFR5) to promote their accumulation at root hair tips in response to rhizobia or NFs. Furthermore, Flotillin 1 (Flot1), a nanodomain-organizing protein, associates with the kinase domains of NFR1, NFR5 and RinRK1. RinRK1 promotes the interactions between Flot1 and NF receptors and both RinRK1 and Flot1 are necessary for the accumulation of NF receptors at root hair tips upon NF stimulation. Our study shows that RinRK1 and Flot1 play a crucial role in NF receptor complex assembly within localized plasma membrane signaling centers to promote symbiotic infection.
豆科植物-根瘤菌根瘤共生涉及根瘤菌 Nod 因子 (NF) 信号被 NF 受体识别，从而触发根瘤器官发生和根瘤菌感染。RinRK1 被 NF 信号诱导，对于 Lotus japonicus 中的侵染线 (IT) 形成是必需的。然而，这一过程的确切机制仍不清楚。在这里，我们表明 RinRK1 与 NF 受体 (NFR1 和 NFR5) 的细胞外结构域相互作用，以促进它们在根毛尖端的积累，以响应根瘤菌或 NF。此外，Flotillin 1 (Flot1)，一种纳米域组织蛋白，与 NFR1、NFR5 和 RinRK1 的激酶结构域相关联。RinRK1 促进 Flot1 和 NF 受体之间的相互作用，并且在 NF 刺激下，RinRK1 和 Flot1 对于 NF 受体在根毛尖端的积累都是必需的。我们的研究表明，RinRK1 和 Flot1 在 NF 受体复合物在局部质膜信号中心的组装中发挥关键作用，以促进共生感染。
