A SERK3-PSKR1 Module Negatively Regulates Rice Resistance to Planthoppers

SERKs (somatic embryogenesis receptor-like kinases), by forming complexes with various receptors, play a crucial role in regulating plant growth, development, and responses to abiotic and biotic stresses. Yet, the role of SERKs in mediating plant defense against herbivores remains largely unknown. Here, we identified a rice SERK gene, OsSERK3, whose expression was induced by mechanical wounding, MeJA treatment, and infestation with brown planthopper (BPH, Nilaparvata lugens). Knocking out OsSERK3 in rice enhanced BPH-induced levels of certain defense-related WRKY transcripts and of JA and JA-Ile but reduced the accumulation of ET, which subsequently promoted the production of defense compounds and the resistance of rice to BPH. Studies on mechanisms revealed that OsSERK3 physically interacted with a rice phytosulfokine receptor, OsPSKR1, and that knocking out OsPSKR1 had similar effects on WRKYs, signaling pathways, and BPH resistance in rice. These findings highlight the pivotal role of the OsSERK3-OsPSKR1 module in regulating rice BPH resistance, offering a potential new approach for controlling rice planthoppers.