Receptor-like proteins: decision-makers of plant immunity

Abstract

Receptor-like proteins (RLPs) are crucial pattern-recognition receptors on the surface of plant cells, which are involved in almost all processes of the plant life cycle. Recently, the evolution of high-throughput sequencing technology has strengthened the appraisal and identification of increasing numbers of RLPs and has primarily improved our understanding of the roles of RLPs in various biological processes. Here, we review the classification and evolutionary characteristics of RLPs and their regulatory roles in pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). In particular, we summarize the ligands recognized by RLPs, their co-receptors, and downstream signalling cascades mediated by RLPs. To summarize, this review offers beneficial guidance for researchers in at-a-glance comprehension of the function of RLPs. It also puts forward the prospect of mining broad-spectrum candidate genes in light of the research on the disease resistance mechanism of RLPs and current challenges in disease resistance breeding.