Jasmonic acid signaling induced by caterpillar damage causes reduced resistance to target insect feeding by the brown planthopper, Nilaparvata lugens (Stål), in rice

Abstract

Abstract A newly developed breeding variety of crops shows high resistance in laboratory conditions but exhibits low resistance to target insects in the field. This research aims to explain this phenomenon from inter-species interactions in insects as the herbivory by one insect species can induce physiological changes in plants that enhance attraction other insect species. The striped stem borer (SSB), Chilo suppressalis (Walker), and the brown planthopper (BPH), Nilaparvata lugens (Stål), are pests of rice (Oryza sativa L.) that cause major losses in grain production. This study examines how BPH feeding behavior on rice is affected by SSB herbivory. BPH performance and behavior were tested on the planthopper-resistant rice variety ‘Mudgo’ with pre-feeding of SSB. BPHs showed better growth and development, as well as feeding behavior, on SSB-damaged plants when compared to healthy/undamaged plants. Analysis of gene expression and phytohormone level revealed changes in the jasmonic acid (JA) biosynthesis in response to SSB feeding. The analysis of central metabolites and volatiles showed that SSB-damaged stem induced the volatiles emission, which benefits planthopper development or attracts BPH. In summary, we found that the JA biosynthesis was triggered by SSB and played a vital role in rice defense against BPH. This provides insight into the molecular and biochemical mechanisms of BPH preferences for SSB-damaged rice plants. Our study emphasizes the crucial role of inter-species interactions in enhancing host plant resistance to insect pests and evaluating germplasm resistance. These findings can serve as a basis for controlling BPH.