The OsIMP1-OsRLK5 immunopeptide-receptor pair confers bacterial and fungal disease resistance in rice.

Abstract

Receptor-like kinases (RLKs) often function as immune receptors of exogenous and endogenous elicitors in plants. However, only a few immune ligand-receptor pairs have been identified in rice. In this study, we report that a rice gene encoding the secretory immunopeptide OsIMP1 is induced by pathogen-associated molecular patterns. The peptide triggers immune responses and positively regulates rice disease resistance. Furthermore, we find that the leucine-rich repeat receptor-like kinases OsRLK5, OsRLK5-L, and somatic embryogenesis receptor-like kinase 2 (OsSERK2) are essential for OsIMP1-triggered immunity. OsRLK5 interacts with and phosphorylates OsSERK2. OsIMP1 directly binds to the extracellular domain of OsRLK5 that positively regulates pattern-triggered immunity. Notably, overexpression of OsRLK5 confers increased resistance to bacterial and fungal diseases without yield penalty in rice. Collectively, this study reveals that OsIMP1 and OsRLK5/ OsRLK5-L form ligand-receptor pairs that modulate multiple disease resistance and uncovers an important strategy how rice plants defend against multiple pathogens without growth penalty.