Mycorrhizal decomposers in the fungal genus Cortinarius

The fungal genus Cortinarius, proposed to combine mycorrhizal symbiosis with a capacity to decompose organic matter, is a key component of boreal forest ecosystems.

In a four-year project, involving a PhD student and collaboration between researchers in Uppsala, Lund, Nancy and London, we will approach the genus Cortinarius from ecological, taxonomic, genetic and biochemical perspectives.We will study the evolution of the enzyme Mn-peroxidase, central for decomposition in forest soils, based on sequencing of mRNA from forest soils and Cortinarius genomes.

The biochemical influence of heterologously expressed Cortinarius Mn-peroxidases on soil organic matter will be assessed in vitro, using isotope-labelled substrates, spectroscopy and bioassays.

We will subject 2600 soil samples to fungal meta-barcoding and enzyme assays, enabling statistical linking of Cortinarius species to enzyme production.

For ecological upscaling, we will use structural equation modelling to relate fungal community data to environmental drivers and organic matter stocks in forest soils.The multi-disciplinary project will pioneer ecological and functional characterization of cryptic soil fungi that are not readily isolated and cultured.

We will test novel hypotheses about how plant-fungus-soil interactions maintain soil fertility and counteract ecosystem retrogression. This knowledge is pivotal to guide sustainable management of forest ecosystems and predict responses to climate change.