The N-glycosylation-related genes as potential targets for RNAi-mediated pest control of the Colorado potato beetle (Leptinotarsa decemlineata)

BACKGROUND N-glycosylation is one of the most common and important post-translational modifications (PTM) in the eukaryotic cell. The study of protein N-glycosylation in several model insects confirmed the importance of this process in insect development, immunity, survival and fertility. The Colorado potato beetle (Leptinotarsa decemlineata) (CPB) is a common pest of Solanaceae crops. With the infamous title of champion of insecticide resistance, novel pest control strategies for this insect are needed. Luckily this pest insect is reported as very sensitive for the post-genomic technology of RNAi. RESULTS In this project, we investigated the importance of N-glycosylation in the survival and development of CPB using RNAi-mediated gene silencing of N-glycosylation-related genes (NGRGs) during the different transition steps from the larva, over the pupa to the adult stage. High mortality was observed in the larval stage with the silencing of early NGRGs, as STT3a, DAD1 and GCS1. With dsRNA against middle NGRGs, abnormal phenotypes at the ecdysis process and adult formation were observed, while the silencing of late NGRGs did not cause mortality. CONCLUSION The lethal phenotypes observed upon silencing of the genes involved in the early processing steps of the N-glycosylation pathway suggest these genes are good candidates for RNAi-mediated control of CPB. Next to the gene-specific mechanism of RNAi for biosafety and possible implementation in IPM (Integrated Pest Management), we believe these early NGRGs provide a possible alternative to the well-known target genes Snf7 and vacuolar ATPases that are now used in the first commercial RNAi-based products and so they can useful in the context of proactive resistance management.