Isolation and characterization of extracellular vesicles from the filamentous fungal pathogen Fusarium oxysporum (#81)
- F. oxysporum is a pathogen of both plants and animals. It affects immunocompromised patients and numerous plants species. Understanding the interaction between the host and the pathogen is important for the development of new methods for disease control. Links between virulence and secretion of extracellular vesicles (EVs) have been reported for a number of yeast fungal pathogens that infect humans. However, the study of EVs from filamentous fungi, particularly in the context of pathogenesis in plants, has been neglected. This study focused on the isolation and characterization of EVs from F. oxysporum f. sp. vasinfectum (Fov), a damaging pathogen of cotton. EVs were collected by ultracentrifugation after 72 h and 120 h of fungal growth. Nanoparticle tracking analysis revealed that EVs from Fov have an average diameter of ∼155 nm (n=3), follow a unimodal distribution, and are produced in a lower abundance compared to mammals or yeast. Visualization of Fov EVs using transmission electron microscopy (TEM) identified two morphologies for isolated particles, one of which closely resembled EVs isolated from other organisms. Quantiation of dsDNA, miRNA and protein using a Qubit 4 fluorimeter found variations of macromolecule concentrations between culturing periods, indicating that secretion of EVs might fluctuate over time. Proteomic analysis of Fov EVs using an Orbitrap mass spectrometer indicated enrichment of proteins with cytoplasmic and carbohydrate-related functions. This study is the first to report on the isolation and characterization of EVs from Fov.