RNAi technology: a new platform for crop pest control

135

134

RNA interference is a phenomenon in which the introduction of double‐stranded RNA (dsRNA) into cells triggers the degradation of the complementary messenger RNA in a sequence‐specific manner. Suppressing expression of vital genes could lead to insect death, therefore this technology has been considered as a potential strategy for insect pest control. There are three main routes of dsRNA administration into insects: (i) injections to the hemolymph, (ii) topical, and (iii) feeding. In this review, we focus on dsRNA administration through feeding. We summarize novel strategies that have been developed to improve the efficacy of this method, such as the use of nano‐based formulations, engineered microorganisms, and transgenic plants. We also expose the hurdles that have to be overcome in order to use this technique as a reliable pest management method. © 2019 Society of Chemical Industry

Section: Strategies For Oral Administration Of Dsrna In Insects and Imentioning

confidence: 99%

Section: Conclusion and Future Perspectivesmentioning

confidence: 99%

Prospects, challenges and current status of RNAi through insect feeding

Kunte

McGraw

Bell

et al. 2019

135

134

“…Another route to apply the knowledge of the role of intracellular proteases to manage insecticide resistance may be through RNAi. This method for gene silencing has been explored for insect pests but presents many problems in development and application . Proteases are favoured amongst targets but many are not intracellular, although all proteases are intracellular when synthesised and before activation.…”

Section: Opportunities For Management Strategies Using Intracellularmentioning

confidence: 99%

“…This method for gene silencing has been explored for insect pests but presents many problems in development and application. 71 Proteases are favoured amongst targets but many are not intracellular, 72 although all proteases are intracellular when synthesised and before activation. In the case of a resistant insect strain the upregulated proteases could be characterised and used as targets for knockdown.…”

Section: Rna Interferencementioning

confidence: 99%

Insecticide resistance and intracellular proteases

Wilkins

2017

Pesticide resistance is an example of evolution in action with mechanisms of resistance arising from mutations or increased expression of intrinsic genes. Intracellular proteases have a key role in maintaining healthy cells and in responding to stressors such as pesticides. Insecticide-resistant insects have constitutively elevated intracellular protease activity compared to corresponding susceptible strains. This increase was shown for some cases originally through biochemical enzyme studies and subsequently putatively by transcriptomics and proteomics methods. Upregulation and expression of proteases have been characterised in resistant strains of some insect species, including mosquitoes. This increase in proteolysis results in more degradation products (amino acids) of intracellular proteins. These may be utilised in the resistant strain to better protect the cell from stress. There are changes in insect intracellular proteases shortly after insecticide exposure, suggesting a role in stress response. The use of protease and proteasome inhibitors or peptide mimetics as synergists with improved application techniques and through protease gene knockdown using RNA interference (possibly expressed in crop plants) may be potential pest management strategies, in situations where elevated intracellular proteases are relevant. © 2017 Society of Chemical Industry.

“…RNA interference (RNAi) has been widely used in entomological research for functional analysis of genes and has emerged as a promising tool for insect pest control. 5,6 RNAi is a conserved eukaryotic mechanism of post-transcriptional gene silencing triggered by double-stranded RNA (dsRNA) molecules. 7 In the cell, the dsRNA is first processed by an RNase III enzyme, called Dicer, into small interfering RNAs (siRNAs) of approximately 20-25 nucleotides.…”

Section: Introductionmentioning

confidence: 99%

Delivery of gene‐specific dsRNA by microinjection and feeding induces RNAi response in Sri Lanka weevil, Myllocerus undecimpustulatus undatus Marshall

Pinheiro

Taylor

et al. 2019

BACKGROUND RNA interference (RNAi) is widely used in entomological research for functional analysis of genes and is being considered as a new tool for insect pest management. Sri Lanka weevil (SLW) is a highly polyphagous pest of agronomically important plants, but currently only a few control methods are available for this insect. RESULTS In the present study, we evaluated the stability of candidate reference genes β‐ACT, α‐TUB, EF1‐α, RPL12 and GAPDH, and identified EF1‐α as the most reliable for gene expression normalization. Four target genes involved in different cellular processes, including Prosα2, RPS13, Snf7 and V‐ATPase A were selected to evaluate whether RNAi response in SLW adults can be triggered by microinjection and oral feeding of their double‐stranded RNAs (dsRNAs). Three days after injection of the dsRNAs for the target genes, their transcript levels were significantly reduced (up to 91.4%) when compared to the control. Additionally, weevils fed with the target dsRNAs showed significant decreases in gene transcript levels and significant mortality was observed in insects treated with Prosα2 and Snf7 dsRNAs (78.6 to 92.7%). CONCLUSION Our data demonstrate that microinjection and feeding of dsRNA produce a strong RNAi response in SLW, indicating that RNAi‐based strategies could be explored to develop a selective and environmentally safe control method against SLW. © 2019 Society of Chemical Industry