Skip to main content
ISMPMI Congress 2025 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.

Poster

Session: Session 1 Presenting Authors at Posters (Odds)

P-361 - Distinct subpopulations of Arabidopsis extracellular vesicles are induced by pathogen infection and inhibit fungal infection

Monday, July 14, 2025
13:30 - 15:15  
Location: Confex Hall 3
Subcellular dynamics and signaling in host-microbe interactions
Though plant extracellular vesicles (EVs) have been observed and associated with immune responses for fifty years, the precise role of plant EVs in immunity is unknown. We used high-resolution density gradient ultracentrifugation, protection assays, and total internal fluorescence microscopy (TIRF-M) to separate, purify, and distinguish distinct subpopulations of Arabidopsis EVs. Extracellular RNA and ARGONAUTE proteins were not associated with EVs of healthy nor infected plants. We characterized the response of plant EV subpopulations to biotic and abiotic stresses, including fungal infection, phytohormone treatment, and changes in temperature. We found that specific EV subpopulations are secreted to the apoplast and the leaf surface in response to fungal infection, while other EV subpopulations were less responsive. Treatment of Arabidopsis seedlings with EVs delayed the progression of Colletotrichum infection by altering fungal germ tube development and morphology. Furthermore, using proximity labeling followed by a reverse genetic screen, we identified several Arabidopsis mutants with EV subpopulation-specific defects and increased susceptibility to Colletotrichum infection. Our data indicate that Arabidopsis EVs are highly heterogenous, that EV subpopulations have differing mechanisms of biogenesis, and that specific EV subpopulations contribute to plant immunity by directly interacting with fungi during early stages of infection, but do not mediate transfer of RNA.