As the global population moves toward an estimated 10 billion people by 2060, the demand for food is rising rapidly. Challenged by the finite amount of arable land, securing crop yield is of utmost importance, but becomes more difficult in the face of climate change, which brings greater pest pressures, extreme weather conditions and soil degradation.
For decades, conventional insecticides have been the primary tools used to protect crops from pests, however, their widespread use raises serious concerns about environmental damage and resistance in pests. This has created an urgent need for safer and more sustainable crop protection solutions; one such alternative is biological pesticides based on double-stranded RNA (dsRNA).
The research
My PhD project investigates the biological effects and environmental fate of dsRNA-based pesticides. The first sprayable dsRNA-based plant protection product was commercialized in the United States in 2024. It is generally perceived to degrade rapidly in the field; however, little systematic data exists on how quickly these products degrade in environmental matrices such as surface of leaves and plants, different soil types or freshwater systems. Particularly if the dsRNA in products is sorbed to particles or packaged within droplets of different composition.
Developing precise and reliable detection methods for dsRNA-based pesticides is therefore a central part of my PhD study, as these tools are essential for tracking their presence and transformation in environmental matrices. To enable this work and study their fate, large quantities of dsRNA are required.
Therefore, in collaboration with fellow PhD student, Mathias Helmer Eskildsen, the first part of my PhD study focused on establishing a cost-effective and scalable production pipeline for dsRNA. Also, we want to define what we mean with “degraded”. Theoretically it means the molecules have decomposed to their element parts, CO2, water and nutrients. In practice, however, for risk assessment purposes, knowing when the biological effect stops may be more important.
To be able to measure biological effect we have worked on optimizing a high-throughput screening of dsRNA candidates and their effects on the potato late blight, Phytophthora infestans, using the oCelloScope automated live-cell imaging system. This allows monitoring the effect of multiple RNA-based treatments (for example “new” RNA and partly decomposed RNA) in real time.
Together with other analytical methods, these approaches will be further refined and optimized to achieve the highest possible resolution when studying the effects and environmental fate of dsRNA-based pesticides.