PT  - JOURNAL ARTICLE
AU  - John D. Howard
AU  - Myriam Beghyn
AU  - Nathalie Dewulf
AU  - Yves De Vos
AU  - Annelies Philips
AU  - David Portwood
AU  - Peter M. Kilby
AU  - Duncan Oliver
AU  - Wendy Maddelein
AU  - Stephen Brown
AU  - Mark J. Dickman
TI  - Chemically modified dsRNA induces RNAi effects in insects <em>in vitro</em> and <em>in vivo</em>: A potential new tool for improving RNA-based plant protection
AID  - 10.1101/2022.02.02.478785
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.02.02.478785
4099  - http://biorxiv.org/content/early/2022/02/02/2022.02.02.478785.short
4100  - http://biorxiv.org/content/early/2022/02/02/2022.02.02.478785.full
AB  - Global agriculture loses over $100 billion of produce annually to crop pests such as insects. Many of these crop pests either have no current means of control or have developed resistance against chemical pesticides. Long dsRNAs are capable of inducing RNA interference (RNAi) in insects and are emerging as novel highly selective alternatives for sustainable insect management strategies. However, there are significant challenges associated with RNAi efficacy in insects. In this study, we synthesised a range of chemically modified long dsRNA in an approach to improve nuclease resistance and RNAi efficacy in insects. The results showed that dsRNA containing phosphorothioate modifications demonstrated increased resistance to southern green stink bug saliva nucleases. Phosphorothioate and 2’-fluoro modified dsRNA also demonstrated increased resistance to degradation by soil nucleases and increased RNAi efficacy in Drosophila melanogaster cell cultures. In live insects, chemically modified long dsRNA successfully resulted in mortality in both stink bug and corn rootworm. The results provide further mechanistic insight of RNAi efficacy dependence on modifications in the sense or antisense strand of the dsRNA in insects and demonstrate for the first time that RNAi can successfully be triggered by chemically modified long dsRNA in insect cells or live insects.Competing Interest StatementThe authors have declared no competing interest.