Within the framework of the JGI Mycorrhizal Genomics Initiative, we are sequencing a phylogenetically and ecologically diverse suite of mycorrhizal fungi (Basidiomycota and Ascomycota), which include the major clades of symbiotic species associating with trees and woody shrubs. Analyses of these genomes will provide insight into the diversity of mechanisms for the mycorrhizal symbiosis, including ericoid-, orchid- and ectomycorrhizal associations.
Cortinarius glaucopus - The Greenfoot Webcap
Cortinarius glaucopus is a representative of the largest fungal genus with over 2000 species of Cortinarius currently recognized. The genus often dominates ectomycorrhizal communities in both the northern and southern hemispheres but is strikingly absent or poorly represented in tropical regions. The phylogenetic breadth of the genus is matched by the very wide range of habitats and hosts with which Cortinarius species associate. The genus is especially abundant in nutrient poor boreal forest ecosystems and the mycorrhizas are characterised by the production of copious amounts of mycelium in the organic soil layers suggesting utilisation of organic nutrient sources. However, we know very little about the physiological capabilities of the genus as free living mycelia of Cortinarius species has only been obtained on very rare occasions.
Cortinarius glaucopus forms ectomycorrhizas with a range of host species that are highly hydrophobic compared to the other taxa proposed and therefore represents an extreme example of this ecological trait and genome data would greatly facilitate an investigation of the evolution and ecological significance of hydrophobin encoding genes across mycorrhizal and saprotrophic fungi.
Surprisingly, recent work, using DNA extracted directly from field-collected fruit bodies, has suggested a role for Cortinarius in the degradation of polyaromatic organic soil residues as class II peroxidase-encoding genes were found to be widespread in the genus.
The analysis of C. glaucopus genome will allow us to identify the evolution in symbiotic fungi of such catabolic genes, which are shared with the free living lignocellulose degrading saprotrophic basidiomycetes.