Abstract: 【Aim】 This study aims to investigate the functions of the ATP synthase b subunit gene in the rice brown planthopper (BPH), Nilaparvata lugens by RNAi and to explore the potential using the gene as a target to control this pest. 【Methods】 The full-length cDNA of ATP synthase b subunit gene was cloned from the BPH reared on rice variety TN1 by RACE according to the sequence information available in the transcriptome data previously obtained by our laboratory. The expression profiles of this gene in different developmental stages and different tissues of the 5th instar nymphs of N. lugens were detected with real-time quantitative PCR, and the RNAi experiments of the gene were carried out with the 2nd instar nymphs of N. lugens by using feeding method. 【Results】 The full-length cDNA of the ATP synthase b subunit gene of the BPH named ATPSb (GenBank accession number: MF973493) was successfully cloned. It contains an ORF of 843 bp, encoding a protein of 280 amino acid residues. Real-time quantitative PCR showed that the ATPSb gene was highly expressed in the 1st and 2nd instar nymphs, and its relative expression level decreased with the developmental stage. The mRNA level of ATPSb was higher in male adults than that in female adults. In the 5th instar nymphs, the mRNA level of ATPSb in the thorax was the highest among different tissues, while relatively low in the head, midgut, ovary and fat body. The RNAi results showed that the mRNA level of ATPSb was significantly decreased in the dsATPSb treatment group from the 6th day, and the RNAi treatment led to distinct mortality of the BPH nymphs. At 18 d after RNAi, the survival rate in the control group kept 80%, while no individual survived in the dsATPSb treatment group. 【Conclusion】 The results suggest that the ATPSb gene is essential to the survival of the BPH, and the RNAi of ATPSb shows an effective inhibition of the BPH. ATPSb may serve as a potential target gene for BPH control.

Key words: Nilaparvata lugens, ATP synthase, ATPSb, RNA interference, survival rate