A fungal plant pathogen discovered in the Devonian Rhynie Chert

• Published in: Nature communications Vol. 14; no. 1; p. 7932
• Main Authors: Strullu-Derrien, Christine, Goral, Tomasz, Spencer, Alan R. T., Kenrick, Paul, Catherine Aime, M., Gaya, Ester, Hawksworth, David L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-12-2023; Nature Publishing Group; Nature Portfolio
• Series: Nature Communications
• Subjects: 14; 14/19; 14/63; 631/1647/328/1978; 631/181/414; 704/158/2462; 704/172; Appendages; Ascomycota; Chert; Cherts; Confocal microscopy; Devonian; Dikarya; Environmental Sciences; Fungi; Humanities and Social Sciences; multidisciplinary; New species; Plant fossils; Science; Science (multidisciplinary); Stroma; Terrestrial ecosystems; United Kingdom > UK; Scotland
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-43276-1

Fungi
are integral to well-functioning ecosystems, and their broader impact on Earth systems is widely acknowledged. Fossil evidence from the Rhynie Chert (Scotland, UK) shows that
Fungi
were already diverse in terrestrial ecosystems over 407-million-years-ago, yet evidence for the occurrence of
Dikarya (
the subkingdom of
Fungi
that includes the phyla
Ascomycota
and
Basidiomycota
) in this site is scant. Here we describe a particularly well-preserved asexual fungus from the Rhynie Chert which we examined using brightfield and confocal microscopy. We document
Potteromyces asteroxylicola
gen. et sp. nov. that we attribute to
Ascomycota incertae sedis (Dikarya)
. The fungus forms a stroma-like structure with conidiophores arising in tufts outside the cuticle on aerial axes and leaf-like appendages of the lycopsid plant
Asteroxylon mackiei
. It causes a reaction in the plant that gives rise to dome-shaped surface projections. This suite of features in the fungus together with the plant reaction tissues provides evidence of it being a plant pathogenic fungus. The fungus evidently belongs to an extinct lineage of ascomycetes that could serve as a minimum node age calibration point for the
Ascomycota
as a whole, or even the
Dikarya
crown group, along with some other
Ascomycota
previously documented in the Rhynie Chert.
Here, the authors describe a pathogenic fungus from a 400-million-year-old fossil plant from the Devonian Rhynie Chert in Scotland. They use advanced imaging methods to determine that the fungus belongs to the sac fungi, the most diverse group of Fungi today.