The combination of NlMIP and Gαi/q coupled-receptor NlA10 promotes abdominal vibration production in female Nilaparvata lugens (Stål)

Abstract

For various sexually mature insects, including the brown planthopper (BPH, Nilaparvata lugens), the abdominal vibration (AV) signal is the initiation of the mating process, and it is critical to the success of mating. Currently, there are few studies on the genetic and molecular mechanisms of AV regulation. Our previous AV-related transcriptomic study in female BPH identified myoinhibitory peptide (NlMIP) as a gene that potentially affects AV status in females, but how NlMIP affects AV status remains unknown. In this study, we confirmed that NlMIP regulates AV production and mating behavior in female BPH. When the RNAi knockdown efficiency of NlMIP was 59.00%, the probability of females producing AV and the mating rate in 1 h decreased by 38.89 and 61.11%, respectively. In addition, six mature peptides of NlMIP were synthesized and they were able to regulate AV production and mating behavior in females, with NlMIP2 having the strongest effect. The A-family neuropeptide GPCR 10 (NlA10) was found to be a potential receptor for NlMIP based on a phylogenetic tree analysis and the fact that NlMIP mature peptides effectively activated NlA10. After NlA10 was knocked down, the probability of females producing AV and the mating rate in 1 h had reductions of 28.89 and 43.33%, respectively. When activated by NlMIP2, NlA10 coupled the Gαi/q signalling pathways, thereby inhibiting the downstream AC/cAMP/PKA, activating the PLC/Ca2+/PKC signalling pathways and then activating MEK1/2 in a cascade to mediate the phosphorylation of ERK1/2, and finally regulating the AV of females. These results provide a basis for the prevention and control of the brown planthopper pest by disrupting female AV.