Current Scenario of Exogenously Induced RNAi for Lepidopteran Agricultural Pest Control: From dsRNA Design to Topical Application

Abstract

Invasive insects cost the global economy around USD 70 billion per year. Moreover, increasing agricultural insect pests raise concerns about global food security constraining and infestation rising after climate changes. Current agricultural pest management largely relies on plant breeding—with or without transgenes—and chemical pesticides. Both approaches face serious technological obsolescence in the field due to plant resistance breakdown or development of insecticide resistance. The need for new modes of action (MoA) for managing crop health is growing each year, driven by market demands to reduce economic losses and by consumer demand for phytosanitary measures. The disabling of pest genes through sequence-specific expression silencing is a promising tool in the development of environmentally-friendly and safe biopesticides. The specificity conferred by long dsRNA-base solutions helps minimize effects on off-target genes in the insect pest genome and the target gene in non-target organisms (NTOs). In this review, we summarize the status of gene silencing by RNA interference (RNAi) for agricultural control. More specifically, we focus on the engineering, development and application of gene silencing to control Lepidoptera through non-transforming dsRNA technologies. Despite some delivery and stability drawbacks of topical applications, we reviewed works showing convincing proof-of-concept results that point to innovative solutions. Considerations about the regulation of the ongoing research on dsRNA-based pesticides to produce commercialized products for exogenous application are discussed. Academic and industry initiatives have revealed a worthy effort to control Lepidoptera pests with this new mode of action, which provides more sustainable and reliable technologies for field management. New data on the genomics of this taxon may contribute to a future customized target gene portfolio. As a case study, we illustrate how dsRNA and associated methodologies could be applied to control an important lepidopteran coffee pest.

Oligonucleotide insecticides (contact unmodified antisense DNA biotechnology) and RNA biocontrols (double-stranded RNA technology): newly born fraternal twins in plant protection

“…The result of RNA interference is the interruption of the biosynthesis of a certain protein molecule. RNAi is highly efficient and systemic in coleopterans (Zhu and Palli, 2020) but is absent in representatives of the order Diptera, Lepidoptera (Terenius et al, 2011; Lucena-Leandro et al, 2022; Christiaens et al, 2018) and sap-feeding Hemiptera (Jain et al, 2021; Kaplanoglu et al, 2022), which limits the use of this approach in plant protection. It took 25 years to create and register the first dsRNA-based insecticides.…”

RNAi FOR THE MANAGEMENT OF INSECT PESTS: A REVIEW

“…The RISC then cleaves the mRNA molecule, preventing it from being translated into protein. RNAi has many important roles in cells, including regulating gene expression during development, maintaining genome stability, and protecting cells from viral infections (Lucena-Leandro et al 2022). In addition to siRNAs, there are other types of small RNA molecules involved in RNAi, including microRNAs (miRNAs) and piwi-interacting RNAs (piRNAs).…”

Editorial: dsRNA-based pesticides: production, development, and application technology

“…Although some technical and application problems remain to be solved, cutting-edge research has proposed feasible solutions to many of these challenges. As technical and application problems are solved one by one the applications of dsRNA-based pesticide in the agricultural are expected to expand ( Lucena-Leandro et al, 2022 ).…”

“…Specifically, dsRNA-based pesticides that use water as carrier can significantly reduce the use of organic chemicals, such as solvents and additives, that are used in chemical pesticides. Moreover, dsRNA-based pesticides can also play an important role in delaying the evolution of resistance to chemical pesticides ( Zotti et al, 2018 ; Mat Jalaluddin et al, 2019 ; Kunte et al, 2020 ; Lucena-Leandro et al, 2022 ). Based on many studies, dsRNA-based pesticides with their unique mode of action, gene silencing, will likely solve many problems related to environmental protection and food safety that traditional pesticides cannot.…”