Arbuscular Mycorrhizal Fungi Increase the Phenolic Compounds Concentration in the Bark of the Stem of Libidibia Ferrea in Field Conditions

<jats:sec> <jats:title>Background:</jats:title> <jats:p> <jats:italic>Libidibia ferrea</jats:italic> is a species particular to the caatinga presenting medicinal properties for containing bioactive compounds. The use of Arbuscular Mycorrhizal Fungi (AMF) can increase the production of biomolecules in the legume leaves; however, no light has been shed on the role of symbiosis in maximizing metabolites production in the bark of <jats:italic>L. ferrea</jats:italic> stem.</jats:p> </jats:sec> <jats:sec> <jats:title>Objective:</jats:title> <jats:p>The aim was to select AMF that are efficient at increasing the production of phenolic compounds with medicinal properties in the bark of the <jats:italic>L. ferrea</jats:italic> stem.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods:</jats:title> <jats:p>The experiment was designed in randomized blocks with four inoculation treatments (plants pre-inoculated with <jats:italic>Claroideoglomus etunicatum</jats:italic>, with <jats:italic>Gigaspora albida</jats:italic>, with <jats:italic>Acaulospora longula</jats:italic>, and non-inoculated plants – control) with six repetitions. Thirteen months after the transplanting, the plants were pruned and the bark of the stem was collected; subsequently, this plant material was dried in a chamber. After the drying process, fractions of the bark of the stem were macerated in methanol. The extracts were further used for analyses of the biomolecules.</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p>The flavonoids concentration had an increase of, respectively, 236% and 186% in relation to the control for the treatments with <jats:italic>A. longula</jats:italic> and <jats:italic>C. etunicatum</jats:italic>; plants inoculated with <jats:italic>A. longula</jats:italic> had an increase of 47% in total tannins concentration compared with the non-inoculated control – a benefit that the proanthocyanidins did not present.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion:</jats:title> <jats:p>Applying inoculation with <jats:italic>A. longula</jats:italic> may be an alternative to increase the production of biomolecules of the secondary metabolism in the bark of the <jats:italic>L. ferrea</jats:italic> stem in field conditions.</jats:p> </jats:sec>