Abstract:  【Aim】This study aims to analyze the functional mechanism of ATP synthase subunit α in the metamorphosis and development of Helicoverpa armigera.【Methods】The open reading frame (ORF) of ATPS-α gene of H. armigera was amplified by PCR and analyzed by bioinformatics. qRT-PCR was employed to detect the expression levels of HaATPs-α in the cuticle, midgut and fat body of larva at the 5th instar molting stage and day-1-5 of the 6th instar, and the cuticle and fat body of the 6th instar larva after the induction of exogenous 20-hydroxyecdysone (20E)(0.1 mg/mL). The 6th instar larvae of H. armigera were injected with dsHaATPs-α, and the effects of knocking down the expression level of HaATPs-α by RNAi on the development and metamorphosis of larvae, and the ATP content, trehalose content, glucose content and trehalase activity in the larva were analyzed. 【Results】The ORF length of HaATPs-α of H. armigera is 1 677 bp. The amino acid sequence identity of ATPs-α in H. armigera, Spodoptera frugiperda, S. litura and Trichoplusia ni of Noctuidae of Lepidoptera was 96.56%, and their evolution relationship was close. The expression pattern analysis result showed that the expression levels of HaATPs-α in the cuticle and midgut of the day-3 6th instar larvae were the highest and also peaked in the fat body of the 5th instar larvae at the molting stage. Treatment with 20E(0.1 mg/mL) significantly upregulated the expression level of HaATPs-α in the 6th instar larvae compared with the control. Compared with the control group (injected with dsGFP), knocking down the expression level of HaATPs-α by RNAi delayed the larval development, significantly reduced larval weight, significantly increased larval mortality, significantly decreased pupation rate and adult emergence rate, significantly decreased ATP content and trehalase activity, significantly increased trehalose content, and significantly decreased glucose content. 【Conclusion】HaATPs-α not only controls ATP production, but also affects the contents of trehalose and glucose in H. armigera. Therefore, HaATPs-α plays an important role in larval metamorphosis. Furthermore, our results also provide experimental evidence and theoretical basis for using ATPs-α as a new target for pest control in the future.

Key words: Helicoverpa armigera, ATP synthase subunit α, ATP, soluble trehalase, metamorphosis