The transport of RNAs within plants and between plants and pathogens is a key factor in plant-pathogen interactions and RNA-based crop protection (further information), especially for the development of next-generation RNA sprays with improved stability, systemic movement, and efficacy against pathogen and pests. Exogenous RNAs face multiple biological barriers on their way to target cells. On the plant surface, dsRNA are exposed to environmental factors such as UV light, rainfall, and RNases from microbial communities. Once taken up by plant tissues via endocytosis, the can be further degraded during intra- and intercellular transport. As RNAs move from cell to cell, their concentration decreases, and only a fraction ultimately reaches distant tissues or target fungal or insect cells, where they must trigger RNAi-mediated gene silencing. Understanding how these physical, cellular, and enzymatic barriers are overcome is essential to achieve effective RNA-based plant protection. Interestingly, barley shows systemic transport of RNAs after RNAi spray, a phenomenon previously observed only in wheat among major crops plants (further information). This raises key questions: what distinguishes barley from other crops in terms of RNA transport, and how can this knowledge be leveraged to develop systemically active RNA-based biopesticides? In the barley-Fusarium system, we are also investigating the potential role of extracellular vesicles (TVs) as natural RNA carriers between organisms. While our results suggest that eVs may contribute to RNA transport, particularly in biotrophic pathogens, their exact role and mechanism in RNAi-based crop protection still needs to be determined.