To resist biotic attacks, plants have evolved a sophisticated, receptor-based immune system. Cell-surface immune receptors, which are either receptor-like kinases (RLKs) or receptor-like proteins (RLPs), form the front line of the plant defense machinery. RLPs lack a cytoplasmic kinase domain for downstream immune signaling, and leucine-rich repeat (LRR)-containing RLPs constitutively associate with the RLK SOBIR1. The RLP/SOBIR1 complex was proposed to be the bimolecular equivalent of genuine RLKs. However, it appears that the molecular mechanisms by which RLP/SOBIR1 complexes and RLKs mount immunity show some striking differences. Here, we summarize the differences between RLP/SOBIR1 and RLK signaling, focusing on the way these receptors recruit the BAK1 co-receptor and elaborating on the negative crosstalk taking place between the two signaling networks.

为了抵抗生物攻击，植物进化出了复杂的、基于受体的免疫系统。细胞表面免疫受体，即受体样激酶（RLK）或受体样蛋白（RLP），构成了植物防御机制的前线。 RLP 缺乏用于下游免疫信号传导的细胞质激酶结构域，并且含有富含亮氨酸重复序列 (LRR) 的 RLP 与 RLK SOBIR1 组成型相关。 RLP/SOBIR1 复合物被认为是真正 RLK 的双分子等价物。然而，RLP/SOBIR1 复合物和 RLK 增强免疫力的分子机制似乎显示出一些显着差异。在这里，我们总结了 RLP/SOBIR1 和 RLK 信号传导之间的差异，重点关注这些受体招募 BAK1 共受体的方式，并详细阐述了两个信号传导网络之间发生的负串扰。