Abstract: 【Aim】 Autophagy participates in various physiological processes of cells. The autophagy-related protein ATG13 is a component of the Atg1/13 complex and plays an important role in initiating the autophagy. This study aims toanalyzethefunctionofATG13inthebrownplanthopper, Nilaparvata lugens, and to evaluate its potential as a pest control target. 【Methods】 Based on the transcriptome data of N. lugens, the full-length cDNA sequence of NlATG13 in N. lugens was cloned via RACE method. The nucleotide and amino acid sequence characteristics of NlATG13 were analyzed with bioinformatics technology. RT-qPCR technology was used to detect the expression patterns of NlATG13 in different developmental stages (1st-5th instar nymphs, and female and male adults) and different tissues (the head, thorax, midgut and fat body of the 5th instar nymphs and the ovary of newly emerged female adults) of N. lugens. The expression of NlATG13 was knocked down by RNAi through microinjection of dsNlATG13 into the 3rd instar nymphs to explore its effect on the survival, and autophagy in the midgut cells of N. lugens. RT-qPCR was used to detect the expression levels of NlGSK3, NlGS and NlGP related to glycogen synthesis and metabolism in the 3rd instar nymphs after RNAi for 4 d. 【Results】 The full-length cDNA sequence of NlATG13 (GenBank accession no.: MF805752) was cloned. It contains an open reading frame of 1 203 bp in length, encoding a protein of 400 amino acids (GenBank accession no.: AWW05678.1). The phylogenetic analysis showed that NlATG13 protein was closely related to ATG13 proteins of Cimex lectularius and Halyomorpha halys among the analyzed species. Developmental expression profiling showed that the expression levels of NlATG13 in the 3rd and 5th instar nymphs were significantly higher than those in the 1st-2nd instar nymphs, female adults and male adults of N. lugens. Tissue expression profiling revealed that the relative expression level of NlATG13 was higher in the head and fat body, but the lowest in the thorax of the 5th instar nymphs of N. lugens. RNAi results showed that in the dsNlATG13 treatment group, glycogen granules were accumulated in midgut cells, the expression levels of NlGS, NlGSK3 and NlGP had no significant change, the ATP content in tissues was significantly decreased and the survival rate of N. lugens significantly decreased as compared to those in the dsGFP control group. The survival rate of N. lugens on day 10 post dsNlATG13 treatment was 41.4%, while that in the dsGFP control group remained at a higher level of 85.6%. 【Conclusion】 RNA interference targeting NlATG13 gene has a significant inhibitory effect on the survival and autophagy of midgut cells in of N. lugens, and NlATG13 gene could be used as a potential target in controlling N. lugens.

Key words: Nilaparvata lugens, NlATG13, RNA interference, gene cloning, autophagy