Resistance to conventional pesticides is increasing worldwide, while the options for new active ingredients is dwindling. Against this backdrop, RNA interference (RNAi), which silences genes in pests, pathogens and weeds, limiting their potential damage to crops, is emerging as a promising alternative for crop protection.
RNAi, which has been the subject of over a decade of research, works by using double stranded RNA to target genetic sequences in problem species. Unlike many chemical controls, it can target intended species, leaving beneficial insects and other non-target organisms unharmed.
There are two main delivery routes for the technology: as crop sprays, which are likely to appeal to organic growers and markets where genetically modified crops are restricted, such as Europe, or incorporated into genetically modified crops, often alongside an established agent such as Bacillus thuringiensis (Bt).
The first major success for RNAi came in 2017, when an RNAi genetically engineered maize was brought to market in the US. In 2023 there was another major milestone, with the approval of the sprayable Ledprona for use against the Colorado potato beetle (Leptinotarsa decemlineata).
As it stands, the question is not so much whether RNAi works — it does, and across a range of applications. The challenge is about how the approach can be the most efficacious tool possible for growers, and exactly what form it will be delivered in for different crop systems. The general consensus, as laid down in a 2024 review, is that there is definitely room for some design improvements.
Recent research shows focus areas
While there have been some difficulties in assembling stable RNAi pesticides, advances have been rapid.
Scientists in China found their ‘fusion’ approach to RNA allowed them to bring together optimal gene fragments to target the peach-potato aphid Myzus persicae, one of the most ubiquitous plant-sucking pests.
This method improved control of the aphid compared to a single-target RNAi approach, while sparing beneficial predators like ladybirds – a step forward in integrated pest management.
Another team in China explored ways to improve the stability and delivery of an RNAi pesticide against the Whitebacked plant-hopper (Sogatella furcifera), which affects rice and sorghum cultivation in Asia and Australia.
In this case, the genetic components were aimed at silencing a detoxification gene which undermines pesticide effectiveness. They created a biochemical ‘envelope’ for the RNA using nanoparticles, as well as including the conventional pesticide pymetrozine in their complex. Their design effectively overcame the pest’s ability to detoxify the pesticide and led to high mortality.
As that group of researchers identified, nanoparticles are likely to play a role in RNAi delivery for sprayed products. A 2024 review by an Indian team underlined that several materials in nanoparticle form, from carbon and chitosan to gold, can shield RNA from degradation, helping it reach its target more reliably in the field.
Just as crucial as delivery is choosing the right genetic targets. A German research group recently developed a screening method to identify genes most likely to cause rapid pest mortality when silenced. Although around 40% of insect genes are potentially lethal when disrupted, the goal is to find those that work quickly and with minimal product use — a big win for both efficacy and cost.
Great promise, early days
Despite the continued progress, RNAi plant protection technologies are still in their early days; proven to work against their targets in labs and the field but lacking widespread commercial adoption outside a few specific cases.
There has also been criticism that while there have been obvious strides towards mainstream options in controlling plant-feeding pests, there has not been the same rate of progress towards developing weed control products using RNAi. Researchers called for improving delivery methods and focusing on particularly problematic weed species.
There are also likely some basic limitations to how widely RNAi might be used. It’s considered a comparatively slow approach to controlling pests and disease, so where crop aesthetics are of prime importance, it’s unlikely to be a frontline option. And in the realm of invertebrate pest control, there are also only a certain number of species that are susceptible to RNAi by feeding. Finally, there’s a classic complaint in the early days of new technologies: it’s simply too expensive right now.
Knowing the risks
Encouragingly, national and international lawmakers seem increasingly open to products using RNAi technology, but there is still work to be done. New ways of assessing the specificity and degradability of RNAi products will need to be designed if the technique is truly going to make a concerted push for the mainstream.
A recent risk assessment found that while RNAi crop protection products have limited potential impacts on the environment and humans, more evidence is needed. The fact that any organism with chromosomes can potentially be subject to RNAi means that stringent analysis of genetic data should be the bedrock of any product release.
With the global market for RNAi pesticides projected to reach $3 billion by 2031, there’s strong motivation to address these questions and bring more products to farmers’ fields.
For growers, RNAi could become an essential tool — particularly in resistance management and sustainable production systems. It’s not a silver bullet, but when combined with other methods in an IPM framework, RNAi offers precision, safety, and the potential to reduce reliance on synthetic chemistry.
The next few years will be crucial. As new products move through trials and regulatory pipelines, early adopter regions like the US could set the pace — but advances in delivery, targeting, and affordability will determine whether RNAi can reach the broader farming community globally.
