Volume 17, Issue 8 p. 2952-2968
Research article

Metagenome sequence of Elaphomyces granulatus from sporocarp tissue reveals Ascomycota ectomycorrhizal fingerprints of genome expansion and a Proteobacteria-rich microbiome

C. Alisha Quandt

Corresponding Author

C. Alisha Quandt

Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331 USA

For correspondence. E-mail [email protected]; Tel. (+1) 734 763 8161; Fax (+1) 734 763 0544.Search for more papers by this author
Annegret Kohler

Annegret Kohler

Institut National de la Recherché Agronomique, Centre de Nancy, Champenoux, France

Search for more papers by this author
Cedar N. Hesse

Cedar N. Hesse

Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA

Search for more papers by this author
Thomas J. Sharpton

Thomas J. Sharpton

Department of Microbiology, Oregon State University, Corvallis, OR, 97331 USA

Department of Statistics, Oregon State University, Corvallis, OR, 97331 USA

Search for more papers by this author
Francis Martin

Francis Martin

Institut National de la Recherché Agronomique, Centre de Nancy, Champenoux, France

Search for more papers by this author
Joseph W. Spatafora

Joseph W. Spatafora

Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331 USA

Search for more papers by this author
First published: 06 March 2015
Citations: 29

Summary

Many obligate symbiotic fungi are difficult to maintain in culture, and there is a growing need for alternative approaches to obtaining tissue and subsequent genomic assemblies from such species. In this study, the genome of Elaphomyces granulatus was sequenced from sporocarp tissue. The genome assembly remains on many contigs, but gene space is estimated to be mostly complete. Phylogenetic analyses revealed that the Elaphomyces lineage is most closely related to Talaromyces and Trichocomaceae s.s. The genome of E. granulatus is reduced in carbohydrate-active enzymes, despite a large expansion in genome size, both of which are consistent with what is seen in Tuber melanosporum, the other sequenced ectomycorrhizal ascomycete. A large number of transposable elements are predicted in the E. granulatus genome, especially Gypsy-like long terminal repeats, and there has also been an expansion in helicases. The metagenome is a complex community dominated by bacteria in Bradyrhizobiaceae, and there is evidence to suggest that the community may be reduced in functional capacity as estimated by KEGG pathways. Through the sequencing of sporocarp tissue, this study has provided insights into Elaphomyces phylogenetics, genomics, metagenomics and the evolution of the ectomycorrhizal association.