Fig. 12.

Putative role of EVs in the pathogen attack response in plants.

Schematic representation of a plant cell penetrated by hyphae from powdery mildew fungus. Pathogen attack results in transport of defence compounds to the attack location near the plasma membrane by polarization of the cytoskeleton. Two routes of vesicle secretion have been identified: (a) Golgi-derived vesicle secretion relying on SNARE complex formation at the plasma membrane and (b) Fusion of MVBs with the plasma membrane leading to release of intraluminal vesicles (exosomes) into the paramural space (in between the cell wall and plasma membrane). Cross-talk may exist between MVBs and the trans Golgi network/early endosomes in sorting proteins for MVB-mediated degradation or recycling/exosome secretion to the plasma membrane. Plasmodesmata connect the paramural space across cell walls and may facilitate transport of cargo released from vesicles over longer distances. [Figure adapted from (714,715)].