Project description: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.
Project description:PP2Cs represent the largest gene family of protein phosphatases. Current research has predominantly focused on the regulation of the PP2C.A family in the abscisic acid (ABA) signaling pathway. However, there is currently no documented research regarding the involvement of PP2Cs in plant responses to biotic stressors. In this study, we found that maize (Zea may) ZmPP2C45 is an essential but insufficient negative regulator of benzoxazinoids. Since BZXs are important defensive metabolites against insect herbivores, we hypothesized that the genetic knock-out of ZmPP2C45 could affect the performance of insect herbivores on these plants.To further investigate how ZmPP2C45 depleted BZX contents, we performed a comparative transcriptomics analysis on the Zmpp2c45 mutants and the wildtype control. As a result, 789 genes were found significantly up-regulated in the mutant plants, whereas 198 genes were down-regulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that BZX biosynthesis-related genes were over-represented among the up-regulated genes in the Zmpp2c45 plants