Abstract: 【Aim】The brown planthopper, Nilaparvata lugens, is a devastating pest of rice worldwide. Functional characterization of the key gustatory receptor (GR) genes of N. lugens is essential for developing novel green management techniques. This study aims to clone the highly-expressed GR gene NlugGR17 in the adult antennae of N. lugens, ascertain its sequence features and expression pattern, and explore its role in N. lugens survival, thereby providing a theoretical foundation for future pest control strategies targeting gustatory receptors. 【Methods】The full-length cDNA sequence of NlugGR17 was cloned based on the transcriptomic data from the adult antennae of N. lugens. The transmembrane domains and phylogenetic relationships of NlugGR17 were analyzed via bioinformatics tools. The expression levels of NlugGR17 in the antennae of the 1st-5th instar nymphs and female and male adults, and the legs of female and male adults were detected by quantitative real-time PCR (qRT-PCR).  NlugGR17 expression was silenced through RNA interference (RNAi), and the subsequent changes in NlugGR17 expression levels in female and male adults of N. lugens post RNAi were detected, and the survival rate of N. lugens adults post RNAi was observed and counted.【Results】The full-length cDNA sequence of NlugGR17 was successfully cloned and obtained. It encodes a protein predicted to possess six transmembrane domains. Phylogenetic analysis revealed that NlugGR17 clusters within a clade of known insect sugar receptors. qRT-PCR result indicated that NlugGR17 was expressed in the antennae of the 1st-5th instar nymphs and both sexes of adults, with the expression levels being significantly higher in female and male adult antennae than in the 1st-5th instar nymphal antennae, and showed weak expression in female and male adult legs. The results of the RNAi experiment showed that RNAi-mediated knockdown of NlugGR17 led to a significant decrease in the survival rate of both female and male adults of N. lugens compared to the control group injected with dsNlugGFP. 【Conclusion】NlugGR17 is a gustatory receptor gene indispensable for N. lugens survival, potentially through its involvement in sugar recognition and energy metabolism. These findings highlight NlugGR17 as a promising molecular target for the development of behavioral regulation-based control techniques against this major pest.

Key words: Nilaparvata lugens, gustatory receptor, gene cloning, gene expression profile, RNA interference