Research on HaNRX, a potential RNAi target gene in Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera, a widespread lepidopteran pest, poses a significant threat to global agricultural production. RNA interference (RNAi) technology has emerged as a promising tool for next-generation pest control; however, identifying highly effective target genes remains a critical challenge. This study focuses on Neurexin (NRX), a synaptic cell adhesion protein essential for synapse formation and function, which has been poorly characterized in lepidopteran species. The insecticidal effects of RNAi-mediated silencing of the H. armigera neurexin-4 (HaNRX) gene were evaluated in both first- and fourth-instar larvae, and the potential of plant-mediated RNAi for pest management was assessed. HaNRX knockdown, achieved through either dsRNA feeding or injection, significantly impaired larval growth and development. Furthermore, feeding on transgenic tobacco expressing dsHaNRX resulted in developmental delays in cotton bollworm larvae. In line with these results, suppression of the NRX ortholog in Spodoptera frugiperda also led to effective control of early-instar larvae. These findings highlight plant-mediated RNAi as a promising strategy for managing H. armigera and position NRX as a valuable target for future RNAi-based pest control approaches.