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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Disease and Pest Management Research Unit » Research » Publications at this Location » Publication #421259
Research Project: Knowledge Based Tools for Exotic and Emerging Diseases of Small Fruit and Nursery Crops

Location: Horticultural Crops Disease and Pest Management Research Unit

Title: Cryptostroma corticale, a plant pathogen associated with a human immune respiratory syndrome displaying mixed viral infections of mycoviruses

Author
item ALCALA BRISENO, RICARDO - Oregon State University
item FEAU, NICOLAS - Natural Resources Canada
item GOMEZ-GALLEGO, MIREIA - Inrae
item MULLER, ELODIE - Inrae
item MARCAIS, BENOIT - Inrae
item AGUAYO, JAIME - Inrae
item Grunwald, Niklaus
item LEBOLDUS, JARED - Oregon State University

Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2026
Publication Date: 2/16/2026
Citation: Alcalá Briseño, R. I., Feau, N., Gomez-Gallego, M., Muller, E., Marcais, B., Aguayo, J., Grünwald, N.J., LeBoldus, J.M. 2026. Cryptostroma corticale, a plant pathogen associated with a human immune respiratory syndrome displaying mixed viral infections of mycoviruses. Virology. 618. Article 110815. https://doi.org/10.1016/j.virol.2026.110815.
DOI: https://doi.org/10.1016/j.virol.2026.110815

Interpretive Summary: Single and mixed infections of viruses infecting fungi (e.g., mycoviruses) have been discovered in the fungus Cryptostroma corticale, a forest pathogen and causal agent of sooty bark disease (SBD) of maple trees. Warmer and drier summers have recently increased the incidence of SBD in France and Switzerland, and C. corticale has been recently reported in Oregon and California. C. corticale spores can cause maple bark disease (MBD), a hypersensitive pneumonitis in humans. These novel Mitovirus and Narnarvirus species were reported infecting multiple isolates of of the fungus C. corticale from the Pacific Northwest and the UK. This tripartite interaction might potentially affect the infectivity of plant pathogens or humans.

Technical Abstract: Viruses are the most ubiquitous pathogens capable of infecting archaea, bacteria, and eukaryotes. Mycoviruses, virus-infecting fungi, have been identified in several asco- and basidiomycetes and occasionally in other groups such as oomycetes and plants. Mixed virus infections are frequently reported, resulting in a range of antagonistic, neutral, or synergetic interactions. In contrast, plant pathogenic fungi associated with viruses often cause hyper– or hypovirulence. This report focuses on single and mixed mycovirus infection of the plant pathogenic fungus Cryptostroma corticale, the causal agent of sooty bark disease (SBD) affecting sycamore maple (Acer pseudoplatanus) in Europe, and in silver maple (Acer saccharinum) in North America, although it has been reported in other maple species. Spores of C. corticale can cause maple bark disease (MBD) in highly exposed humans, causing hypersensitive pneumonitis and allergic asthma with viral-like symptoms. In this study, we identified four species of single-stranded positive sense (ss+) RNA mycoviruses that are phylogenetically diverse, including one Mitovirus, Cryptostroma corticale mitovirus 1 (CcMV1), and three Narnavirus species, Cryptostroma corticale narnavirus 1, 2, and 3 (CcNV1, CcNV2, and CcNV3). Notably, a highly structured 5' and 3' UTR were identified in CcMV1, and two narnaviruses, CcNV1 and CcNV3. The discovery of these novel mycoviruses in C. corticale reveals a potential tripartite interaction with potential effects on the infectivity of plant pathogens (SBD) whose spores can infect humans (MBD).