Do leaf phytochemical fingerprints vary with mycorrhizal association?

Mycorrhizal symbiosis is a ubiquitous plant-fungal association widespread across the plant kingdom. Considering the different characteristics and distributions of arbuscular (AM) and ectomycorrhizal (EM) fungal types across biomes, mycorrhizal types can be associated with different climatic and edaphic conditions, reinforced by feedback between soil conditions and plant traits. Although it is becoming clear that AM and EM trees differ in leaf litter quality and nutrient acquisition strategies, studies investigating how leaf traits differ across mycorrhizal associations have led to contrasting results. Here for the first time, we used a combination of quantitative targeted measurements and an untargeted metabolomic approach on 32 European tree species to demonstrate that AM and EM-associated tree species show distinct leaf metabolic fingerprints. Finally, we discuss the link between AM and EM function with key leaf metabolites that emerged from our integrated metabolomic approach.