Investigating differences in the metabolomes of ectomycorrhizal fungi and their link to GHG fluxes

Mycorrhizal fungal species are widespread across nearly all ecosystems worldwide and are generally found in symbiotic association with most plant species. In forested ecosystems, mycorrhizal fungi play a crucial role in facilitating plant nutrient acquisition and defending the plant from abiotic and biotic stress events, such as drought or pathogen attack.

We have recently shown that different tree species that associate with either arbuscular mycorrhizal (AM) fungi or ectomycorrhizal (EM) fungi exhibit distinct phytochemical differences, that might be linked to the type of fungal symbiont. In this study, we investigated the metabolic diversity of several ectomycorrhizal (EM) fungal species commonly found in forests, with the aim of linking their metabolic toolkits to functional processes important in forest ecosystems, such as soil respiration and enzyme activities.

In this presentation, we show that ectomycorrhizal fungi contain a diverse suite of metabolites (> 10000 metabolic features in the 5 species studied) composed largely of lipids and benzenoids with many of these metabolic features serving as reliable predictors that facilitate the distinction of different EM fungal species from one another.

We also present the results of a microcosm gas exchange experiment on the 5 EM fungal species grown under controlled temperature and CO₂ concentration conditions to investigate the link between fungal metabolic profiles and primary functions, such as respiration and enzymatic activity.

This research aims to deepen our understanding of plant-fungal symbioses in forests and the potential shifts in plant and fungal metabolism and function during interaction with one another and when exposed to changes in climate and atmospheric chemistry.

Arette-Hourquet P., Demullier E., Ogée J., Guzman T., Valls-Fonayet J. Petriacq P., Devert N., Ubierna N. Wingate L.