Xuexia Zhang, Hongyun Ruan, Changyu Zhang
Ostrinia furnacalis (Guenee) (Lepidoptera: Crambidae) is a major lepidopteran pest that inflicts severe damage to maize. The biosynthesis of 20-hydroxyecdysone (20E), a steroid hormone vital for insect growth, development, and reproduction, depends critically on the cytochrome P450 monooxygenase CYP314A1. In this study, OfCYP314A1 was identified and characterized its expression patterns across different developmental stages and tissues of third-instar larvae. The results demonstrated that OfCYP314A1 exhibited higher expression levels prior to molting compared to post-molting stages. And the tissues expression analysis revealed peak expression in the fat body of third-instar larvae with 8.067. Compared to the dsGFP-injected control, larvae injected with dsCYP314A1 exhibited significantly reduced survival and molting rates from the second day, culminating in reductions of 30% and 27.6%, respectively, by the sixth day. Larvae injected with dsCYP314A1 showed significantly decreased body weight, shortened body length, and impaired molting accompanied by melanization. Concurrently, 20E levels declined, while juvenile hormone levels increased. These results indicate that OfCYP314A1 regulates molting and growth in O. furnacalis by modulating 20E biosynthesis. This study provides a theoretical basis for targeting OfCYP314A1 in the development of novel control strategies against this destructive pest, particularly through RNAi-based pest management or the screening of CYP314A1-specific inhibitors.