Functional characterization of RNAi candidate target genes in Monolepta hieroglyphica (Motschulsky) for potential pest control applications

Abstract

Monolepta hieroglyphica (Motschulsky) (Coleoptera; Chrysomelidae) is a major agricultural pest affecting maize crops in northern and northwestern China. RNA interference (RNAi) technology offers a strategy for sustainable pest control by targeting and silencing specific genes, reducing reliance on chemical pesticides. In this study, we investigated four genes from M. hieroglyphica genome: V-type ATPase subunit A (MhVATP-A), coat protein complexes I β’ subunit (MhCOPI-β’), cytochrome P450 reductase (MhCPR) and tyrosine decarboxylase (MhTDC) as potential RNAi targets for RNAi-mediated pest control. Through dsRNA injections in adult, we successfully achieved gene silencing in M. hieroglyphica, resulting in significantly reduced expression levels of the target genes. Silencing of MhVATP-A and MhCOPI-β’ resulted in a marked increase in mortality (60–80%), suggesting that these genes play critical roles in essential physiological functions, such as cellular PH regulation and vesicular transport. In contrast, MhCPR suppression resulted in moderate mortality (30%), indicating that while it influences detoxification processes, it may be less effective as a primary target for pest control. MhTDC silencing, involved in nervous system regulation, had no significant impact on adult insect survival, possibly due to compensatory physiological mechanisms. Overall, our findings demonstrate the potential of RNAi technology to target essential genes in M. hieroglyphica, leading to significant insect mortality. The results highlight MhVATP-A and MhCOPI-β’ as promising targets for RNAi-based transgenic maize, offering a species-specific approach for sustainable pest management in maize production. Further investigation is required to assess the effectiveness of RNAi across different development stages and environmental conditions.