Is the application of arbuscular mycorrhizal fungi an alternative to increase foliar phenolic compounds in seedlings of Mimosa tenuiflora (Wild.) Poir., Mimosoideae?

The legume Mimosa tenuiflora (Wild) Poir occurs in the “Caatinga” and is used as a popular remedy because of its medicinal properties related to the presence of secondary compounds in several parts of the plant. The arbuscular mycorrhizal fungi (AMF) are associated with most legumes, including M. tenuiflora, benefiting the growing process and the production of secondary compounds; however, the production of phytochemicals in response to AMF inoculation has not been defined yet. The aim of this study was to evaluate the influence of AMF on the production of phenolic compounds in the aerial part of M. tenuiflora. We analyzed the following parameters: height, stem diameter, number of leaves, fresh matter from the aerial part, dry matter from the aerial part, mycorrhizal colonization, soluble carbohydrates, total proteins, total phenols, total flavonoids, and total tannins. The mycorrhizal association did not benefit the growing process and/or the production of secondary compounds, demonstrating that mycorrhizal technology is not always an alternative to increase the production of plant secondary metabolism molecules. This study is the first report on the results of the inefficiency of mycorrhizal symbiosis regarding the optimization of phenolic compounds in plants of the “Caatinga”.