miR-34-5p, a potential RNA biopesticide for controlling Spodoptera frugiperda by targeting of SfEcR and SfE74.

Spodoptera frugiperda is an agricultural pest with strong adaptability and migration ability. For decades, chemical control has been an important technical measure for controlling S. frugiperda. In the field of pest control, research on RNA biopesticides mainly focuses on dsRNA, and the application of miRNA biopesticides is still in its infancy. The miR-34 family is a multifunctional family that plays key roles in organ development, organism or organ aging, stress response, spermatogenesis, and signal transduction. In this study, we analyzed the physiological function of miR-34-5p by upregulating and downregulating its level, combined with a series of methods such as target site prediction, dual luciferase reporter gene detection, related gene expression, and intestinal reactive oxygen species (ROS) level detection. miR-34-5p plays a crucial role in the metamorphosis and development of S. frugiperda larvae. Among them, the molting related genes SfEcR and SfE74 were identified as the target genes for miR-34-5p, which suggests that miR-34-5p has the potential to serve as an RNA biopesticide. This work provides novel directions and ideas for the prevention and green control of S. frugiperda.