Arbuscular mycorrhizal fungi positively modulate the production of plant bioactive compounds under greenhouse conditions and in experimental fields; however, their role in naturally occurring trees is poorly understood. This research aimed to verify the relationship between mycorrhizal activity and the concentration of foliar biomolecules in a natural population of Anadenanthera colubrina. Leaves and rhizosphere soil were collected from ten individuals of two fragments during the dry and rainy seasons. Foliar metabolite concentrations were quantified, while the soil was used to evaluate mycorrhizal colonization and glomalin-related soil proteins (GRSPs). Mycorrhizal colonization showed a positive correlation (p ≤ 0.05) with metabolite production only during the dry season. GRSPs has higher deposition during the dry season, but has a positive correlation (p ≤ 0.05) with metabolite production only in the rainy season. Both seasons influenced metabolite concentration, with the highest accumulation occurring during the rainy season. Therefore, mycorrhizal colonization and GRSPs deposition are related to the production of foliar metabolites of A. colubrina in a natural environment, but this relationship is strongly modulated by local rainfall.
Carvalho et al. (Thu,) studied this question.