College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing, 210095, China.
Nat Commun. 2023 Jul 31;14(1):4593. doi: 10.1038/s41467-023-40171-7.
Plant cell-surface leucine-rich repeat receptor-like kinases (LRR-RLKs) and receptor-like proteins (LRR-RLPs) form dynamic complexes to receive a variety of extracellular signals. LRR-RLKs are also widespread in oomycete pathogens, whereas it remains enigmatic whether plant and oomycete LRR-RLKs could mediate cell-to-cell communications between pathogen and host. Here, we report that an LRR-RLK from the soybean root and stem rot pathogen Phytophthora sojae, PsRLK6, can activate typical pattern-triggered immunity in host soybean and nonhost tomato and Nicotiana benthamiana plants. PsRLK6 homologs are conserved in oomycetes and also exhibit immunity-inducing activity. A small region (LRR5-6) in the extracellular domain of PsRLK6 is sufficient to activate BAK1- and SOBIR1-dependent immune responses, suggesting that PsRLK6 is likely recognized by a plant LRR-RLP. Moreover, PsRLK6 is shown to be up-regulated during oospore maturation and essential for the oospore development of P. sojae. Our data provide a novel type of microbe-associated molecular pattern that functions in the sexual reproduction of oomycete, and a scenario in which a pathogen LRR-RLK could be sensed by a plant LRR-RLP to mount plant immunity.
植物细胞表面富含亮氨酸重复的类受体激酶 (LRR-RLKs) 和类受体蛋白 (LRR-RLPs) 形成动态复合物，以接收各种细胞外信号。LRR-RLKs 在卵菌病原体中也广泛存在，而植物和卵菌 LRR-RLKs 是否能够介导病原体和宿主之间的细胞间通讯仍然是个谜。在这里，我们报告了一种来自大豆根和茎腐烂病原体大豆疫霉的 LRR-RLK，即 PsRLK6，可以在宿主大豆和非宿主番茄和本氏烟中激活典型的模式触发免疫。卵菌中的 PsRLK6 同源物是保守的，也表现出诱导免疫的活性。PsRLK6 胞外结构域中的一个小区域（LRR5-6）足以激活 BAK1 和 SOBIR1 依赖性免疫反应，表明 PsRLK6 可能被植物 LRR-RLP 识别。此外，研究表明 PsRLK6 在卵孢子成熟过程中上调，并对大豆疫霉的卵孢子发育至关重要。我们的数据提供了一种新型的微生物相关分子模式，该模式在卵菌的有性生殖中起作用，并且病原体 LRR-RLK 可以被植物 LRR-RLP 感知，从而引发植物免疫。
