Chemosensory Protein 2 of Male Athetis lepigone Is Involved in the Perception of Sex Pheromones and Maize Volatiles

In moths, the interactions between chemosensory proteins (CSPs) and sex pheromones have yet to be comprehensively investigated. Here, we examined the function of AlepCSP2 in male Athetis lepigone based on protein expression, molecular docking, site-directed mutagenesis, fluorescence competitive binding analyses, and RNA interference (RNAi) experiments. We found that AlepCSP2 showed strong binding affinity for two sex pheromones and five maize volatiles and that binding was optimal under neutral conditions. Furthermore, we identified six amino acids as being key residues involved in the interaction between AlepCSP2 and multiple ligands. Further RNAi showed that siCSP2 males displayed consistently lower electro-antennography responses to two sex pheromones and three maize volatiles at different dosages tested, and the mating rate also decreased significantly by 37.50%. These findings will contribute to characterizing the binding mechanisms of moth CSPs to sex pheromones and host volatiles and also identify unique targets for developing novel pest behavior disruptors.

Automated summary

In this study, the interaction between chemosensory proteins (CSPs) and sex pheromones in moths was investigated. AlepCSP2 was found to bind strongly to two sex pheromones and five maize volatiles under neutral conditions. RNA interference (RNAi) experiments revealed that siCSP2 males had lower electro-antennography responses to sex pheromones and maize volatiles and a significantly decreased mating rate. These findings contribute to understanding the binding mechanisms of CSPs in moths and identifying targets for pest behavior disruptors.