Can RNA Interference Replace Chemical Pesticides in Agriculture?

A new project-funded study examines how RNAi technology offers species-specific pest control without harming beneficial insects

RNA interference technology is emerging as a powerful tool for sustainable pest management in agriculture and conservation. RNAi works by silencing genes essential for pest survival, offering species-specific control that leaves beneficial organisms unharmed. The pharmaceutical industry has already validated the approach over 25 years of research, with the FDA approving multiple RNAi-based drugs since 2018. This track record of safety and efficacy provides confidence that the technology can transfer effectively to agricultural pest control applications, addressing growing concerns about pesticide resistance, environmental impacts, and human health.

---

How does RNA interference work?

RNA interference operates through a molecular mechanism of elegant simplicity. In all living organisms, genes are transcribed into messenger RNA (mRNA), which is then translated into proteins that carry out biological functions. RNAi technology introduces small interfering RNA (siRNA) molecules designed to match precisely the sequence of target genes in pest species. When these synthetic RNA sequences encounter the target mRNA in pest cells, they trigger degradation of the messenger molecule, preventing protein synthesis. The pest cannot produce the protein, the biological process fails, and the organism dies. This specificity allows researchers to target essential genes in pest species whilst leaving non-target species' genes completely unaffected.

Applying RNAi to agricultural pests offers distinct advantages over conventional pesticides. Chemical insecticides kill through broad toxicity mechanisms affecting many organism types—they disrupt nervous systems or cellular respiration non-specifically. This lack of specificity poisons beneficial insects including pollinators, predators, and parasitoids that control pests naturally. Pest populations evolve resistance as individuals carrying resistance genes survive pesticide exposure and reproduce. Environmental persistence contaminates soil and water ecosystems. RNAi-based approaches address each of these concerns through fundamental specificity: only organisms containing the target gene sequence experience effects, making RNAi intrinsically compatible with biological control and ecosystem health.

Developing RNAi solutions for agriculture

Developing RNAi solutions requires careful target gene selection. Researchers identify genes essential for pest survival, reproduction, or feeding that have no homologues in beneficial organisms or crops. These become ideal targets—silencing them kills the pest whilst leaving everything else untouched. However, some agricultural pests are closely related to crop plants or beneficial insects, complicating target selection. A pest gene sequence might bear sufficient similarity to important genes in non-target species to trigger unintended effects. Overcoming this challenge requires extensive sequence analysis, computational modelling, and rigorous testing across target and non-target species before field deployment.

Delivery mechanisms present the next technical hurdle. RNAi molecules must reach target pest cells to be effective, yet pests don't naturally consume therapeutic compounds. Researchers explore multiple delivery strategies: expressing RNAi molecules in transgenic crops that pests feed upon, coating seeds with RNAi molecules targeting seed-eating insects, or spraying RNAi formulations like conventional pesticides.

Regulatory frameworks must evaluate safety, efficacy, and environmental fate for each delivery system independently. The development of RNAi pest control reflects broader trends harnessing molecular biology for sustainable agriculture.

Read the research here: https://doi.org/10.3176/evp.2024.0. Explore more publications at https://www.framework-biodiversity.eu/publications.