P-109 - Beyond “spray and pray” – Understanding mechanisms of exogenous RNA uptake and stability in plants

Exogenous RNA applications are gaining momentum as innovative tools in crop protection and research. Using the mechanism of RNA interference (RNAi), they allow highly specific silencing of mRNA targets, not only in plants but also in a wide range of pests and pathogens. For an effective RNAi response, efficient uptake of exogenous RNAs into plant leaves is essential. However, several biological barriers must be overcome to transport RNA molecules from the leaf surface into the mesophyll and ultimately into target cells. In addition, exogenous RNAs require protection from premature degradation to maintain their efficacy. While RNA-based approaches are advancing rapidly, their successful implementation in different plant species remains a challenge. Establishing a functional and efficient exogenous RNA delivery system is often a time-consuming process, complicated by species-specific anatomical and biochemical factors. As a result, optimisation still follows a trial-and-error approach, often described as “spray and pray”. To overcome these limitations, we aim to identify the key mechanistic factors influencing RNA uptake, stability, and systemic movement by analysing anatomical, phenotypic, and biochemical features in different plant species. This will serve as a basis for optimising RNA delivery strategies, facilitating the transition of RNAi-based technologies from laboratory research to practical agricultural applications. Our latest findings in this area will be presented.