LAUSR

Summary Rice is a staple food crop worldwide, and its production is severely threatened by phloem‐feeding insect herbivores, particularly the brown planthopper (BPH, Nilaparvata lugens), and destructive pathogens. Despite the identification of many BPH resistance genes, the molecular basis of rice resistance to BPH remains largely unclear. Here, we report that the plant elicitor peptide (Pep) signalling confers rice resistance to BPH. Both rice PEP RECEPTORs (PEPRs) and PRECURSORs of PEP (PROPEPs), particularly OsPROPEP3, were transcriptionally induced in leaf sheaths upon BPH infestation. Knockout of OsPEPRs impaired rice resistance to BPH, whereas exogenous application of OsPep3 improved the resistance. Hormone measurement and co‐profiling of transcriptomics and metabolomics in OsPep3‐treated rice leaf sheaths suggested potential contributions of jasmonic acid biosynthesis, lipid metabolism and phenylpropanoid metabolism to OsPep3‐induced rice immunity. Moreover, OsPep3 elicitation also strengthened rice resistance to the fungal pathogen Magnaporthe oryzae and bacterial pathogen Xanthamonas oryzae pv. oryzae and provoked immune responses in wheat. Collectively, this work demonstrates a previously unappreciated importance of the Pep signalling in plants for combating piercing‐sucking insect herbivores and promises exogenous application of OsPep3 as an eco‐friendly immune stimulator in agriculture for crop protection against a broad spectrum of insect pests and pathogens.