Arbuscular mycorrhizae induce a global metabolic change and improve the nutritional and health benefits of pennyroyal and parsley

This study was conducted to investigate the potential use of arbuscular mycorrhizal fungi (AMF), Rhizophagus irregularis, as an innovative cultivation procedure to improve the production and quality of two medicinal plants, pennyroyal (Mentha pulegium), and parsley (Petroselinum hortense). We elucidated the impact of AMF on soil properties and growth and metabolic profiling of pennyroyal and parsley. AMF treatment improved the availability of essential elements and phenols in the rhizospheric soil. Plant biomass production and photosynthetic rate were improved. We also recorded improved primary and secondary metabolism, where the levels of most of the detected soluble and insoluble sugars, organic acids, essential (isoleucine and valine), and non-essential (glutamine, alanine, and cysteine) amino acids, fatty acids (especially unsaturated fatty acids), phenolic acids, and flavonoids were increased. Overall, this study supports the use of AMF in the artificial cultivation, as an alternative to the chemical fertilizers, for the production of high-quality medicinal plants with enhanced levels of bioactive compounds.