AdsRNAdelivery system based on the rosin‐modified polyethylene glycol and chitosan induces gene silencing and mortality inNilaparvata lugens

Abstract

BACKGROUND: RNA interference (RNAi) technology has been considered as a promising pest control strategy due to its species selectivity. One of the popular RNAs is exogenous double strand RNA (dsRNA). However, dsRNA is easily degraded by nucleases and is difficult to pass through the insect body walls, and these factors restrict the application of RNAi technology in pest management. Here, the brown planthopper (BPH, Nilaparvata lugens), a major hemipteran pest of rice in Asia countries was used as a model insect, and a dsRNA topical delivery system was constructed.RESULTS: The carrier part of the delivery system was composed of rosin-modified polyethylene glycol and chitosan, termed ROPE@C. When the N/P ratio was greater than 1:1.25, the dsRNA/ROPE@C complex encouraged full binding of the dsRNA. The gel electrophoresis results showed that ROPE@C improved the stability of dsRNA in the presence of nucleases in gut and lumen contents for at least 6 h and in the temperature range from 4 °C to 37 °C. The dsNlCHSA/ROPE@C/alkyl polyglycoside (APG) nano-formulation directly penetrated the body walls reaching hemocoel within 6 h, and consequently, the relative expression of chitin synthetase A (CHSA) in BPH was reduced by 54.3% and the mortality rate was 65.8%. CONCLUSION:We developed an appropriate delivery method for dsRNA application in BPH, which is helpful for a large-scale application of RNAi pesticides.

RNAi‐mediated knockdown of papilin gene affects the egg hatching in Nilaparvata lugens

“…68 APG is known for its ecofriendly, nontoxic and mild non-ionic surfactant characteristics, typically blended with other surfactants to improve their permeability. 69 Additionally, APG can expedite the cellular uptake of nanoformulations by enhancing the flow of biofilm and promoting endocytosis of cell membranes. 70,71 Our formulation, comprising dsRNA/LDH/APG nanostructures, is designed to enhance RNAi effects.…”

Evaluation of non-invasive dsRNA delivery methods for the development of RNA interference in the Asian tiger mosquito Aedes albopictus

“…Although it was successfully used for dsRNA insecticide-based approaches in mosquitoes and other insects [68][69][70][71], their nonspeci c impact on untargeted species should then be regarded when evaluating the e ciency of such method.…”

RNAi-chitosan biopesticides for managing forest insect pests: an outlook

“…Additionally, RCNPs were stable for 5 days on leaf surfaces, effectively protected from nuclease degradation and insect gut pH, and efficiently knocked down the targeted genes (JHAMT and AChE), resulting in 100% insect mortality, whereas the nontargeted insects like Spodoptera litura and Drosophila melanogaster were unaffected and showed no signs of toxicity (Kolge et al, 2021(Kolge et al, , 2023. A recent study demonstrated that topically applying dsRNAcoated with rosin-modified PEG and chitosan (dsRNA/ROPE@C) to Nilaparvata lugens (Brown plant hopper) causes excellent gene knockdown and mortality (Lyu et al, 2023). Recently, our team created chitosan-dsRNA nanopesticides, fed them to bollworms (Earias vittella), and observed considerable target gene knockdown and mortality (Sandal et al, 2023).…”