P-332 - RNA sprays and their formulations: Effects on plant physiology and microbial interactions

While synthetic pesticides are widely used due to their ease of application and high efficacy, their unintended effects on non-target organisms contribute to environmental pollution and biodiversity loss. To address this challenge, exogenous application of formulated RNA molecules is emerging as a promising alternative for sustainable crop protection. However, the success of this technology depends critically on formulation strategies that enhance RNA stability and uptake while minimising unintended physiological effects on plants. For example, chitosan-based formulations can induce plant immune responses such as stomatal closure, which can affect plant growth and pathogen susceptibility. In this study, we are investigating the broader physiological effects of RNA formulations beyond their intended protective function. Specifically, we are investigating how plants perceive RNA molecules and formulation components, including chitosan and lipid nanoparticles, in the monocot crops barley and maize. Using leaf disc ROS assays, we are analysing plant responses when perceiving these formulations. We will also investigate the role of the phyllosphere microbiome in RNA stability by comparing RNA degradation rates on leaf surfaces under sterile and non-sterile conditions using qPCR assays. Our findings will help to optimise RNA-based plant protection strategies by balancing efficacy with minimal unwanted effects on plant physiology and microbial interactions.