RNA-based technologies for insect control in plant production

RNA interference (RNAi) is a biological process in which small RNA (sRNA) molecules sequence-specifically silence gene expression at the transcriptional or post-transcriptional level, either by directing inhibitory chromatin modifications or by decreasing the stability or translation potential of the targeted mRNA. The trigger for gene silencing is double-stranded RNA (dsRNA) generated from an endogenous genomic locus or a foreign source, such as a transgene or virus. The process of gene silencing can be exploited in agriculture to control plant diseases and pests. Of the pests that impact crop yield (including nematodes, arthropods, rodents, snails, slugs and birds), insects constitute the largest and most diverse group. Here, we review the "pros" and "cons" of using RNAi technology mediated by dsRNA-expressing transgenic plants (host-induced gene silencing, HIGS) or direct application of chemically synthesized dsRNA to control plant-damaging insects. Rapid progress in elucidating RNAi mechanisms has led to the first commercial products on the market. Given the high potential of RNAi strategies, their use in agriculture, horticulture, and forestry will likely be extensive in the future. However, further studies are needed to improve the efficacy of RNAi-based plant protection strategies and to assess their associated safety risks.