RNA interference-based crop protection against downy mildew pathogens
A sprayable double-stranded RNA (dsRNA) technology that silences essential pathogen genes to control downy mildew diseases in crops such as lettuce and pea. The approach leverages the pathogen's own RNA silencing machinery to inhibit spore germination and infection, offering a targeted alternative to conventional fungicides.
Overview
Downy mildews are destructive oomycete pathogens that threaten lettuce, pea, and other crop production worldwide. This solution applies synthetic double-stranded RNA (dsRNA) directly to plants or seeds to trigger RNA interference (RNAi) in the invading pathogen. Once taken up by fungal or plant cells, the dsRNA is processed into small interfering RNAs (siRNAs) that guide the pathogen's silencing machinery to suppress essential genes, blocking spore germination, infection, and sporulation.
The technology has been validated across three different downy mildew species and more than 50 target genes, with conserved targets such as CesA3 identified for translational development. By targeting pathogen-specific genes, this approach offers a precision biocontrol strategy that can reduce reliance on traditional chemical fungicides and support integrated disease management programs.
Technical specifications
Key features:
- Sprayable or seed-coated dsRNA formulations designed against conserved downy mildew genes such as CesA3
- Exploits the pathogen's Dicer-like (DCL) proteins and RNA-induced silencing complex to achieve gene knockdown
- Demonstrated efficacy in Arabidopsis, lettuce, and pea downy mildew systems
- Validated through germination assays, infection assays, qRT-PCR, imaging, and tissue staining with multiple biological replicates
- Compatible with foliar spray application before or after infection and with seed treatment by spraying or imbibement
- dsRNA stabilization strategies under development to maintain efficacy during seed storage of up to eight weeks
Technology readiness level
The technology is at an early-to-mid translational stage. Fundamental proof-of-concept has been published in peer-reviewed work, and a competitive BBSRC grant supports reverse genetics across 250 downy mildew genes to further elucidate pathogenicity factors. Current efforts focus on scaling the approach from laboratory validation to field-relevant delivery methods, including seed coating and foliar spray formulations for lettuce and pea. Further validation is needed to confirm disease suppression under commercial growing conditions and to optimize dsRNA stability and cost-effective production at scale.
About University of Worcester
The University of Worcester is a modern public university with a professional, applied focus and a growing research profile. Industry partners engage through city-center facilities, collaboration spaces, and consultancy pathways that make it easy to scope, prototype, and evaluate. Integration with regional NHS hospital trusts and community providers supports clinical studies, while human performance facilities, environmental monitoring units, and data resources enable real-world testing. Research is supported by competitive funding from UK Research and Innovation, Innovate UK, the National Institute for Health and Care Research, and charitable foundations. An enterprise and IP team manages contracts, Knowledge Transfer Partnerships, licensing, and spinout support.
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