Unveiling the antifungal arsenal: proteomic profiling of tomato exosomes

MAIN CONCLUSION: Tomato-derived extracellular vesicles selectively package antifungal defense proteins and significantly suppress fungal spore growth and germination, supporting their role as coordinated plant immune delivery systems. Extracellular vesicles (EVs) are significant facilitators of plant-pathogen communication. However, their role as organized antifungal protein delivery systems is not fully understood. This study investigated whether tomato (Solanum lycopersicum) EVs have a unique set of antifungal proteins that helps prevent the growth of phytopathogenic fungi. EVs were extracted from mature tomato fruits and characterized using transmission electron microscopy and dynamic light scattering. They were then analyzed through LC-MS/MS-based proteomic profiling. We identified 133 high-confidence proteins in total; several are involved in defense mechanisms, including pathogenesis-related proteins, defensins, endochitinases, glucanases, osmotin-like proteins, and lipid transfer proteins. Proteins involved in quality control, vesicle trafficking, and metabolic regulation were also enriched. This suggests that EV cargo may participate in stress-responsive and defense-related processes. These functional categories are commonly associated with plant immune responses. Biological assays showed that the density and germination of Fusarium oxysporum, Fusarium solani, and Botrytis cinerea spores were reduced in a dose-dependent manner. These results bolster the hypothesis that tomato-derived EVs are enriched with antifungal-associated proteins and may serve as coordinated delivery vehicles in plant defense responses. Independent proteomic analysis of EV cargo may contribute to antifungal responses that are not apparent from total secretome analysis alone. The present research improves our understanding of how vesicles help plants fight disease and indicates how plant EVs could be used in long-term disease control strategies. Overall, these findings highlight the potential of plant-derived EVs as innovative, biologically driven tools for enhancing crop protection and developing sustainable antifungal strategies in agriculture.