Arbuscular mycorrhizal fungi impact metabolites production of Anchusa officinalis L. and Alkanna tinctoria Tausch by Annalisa Cartabia

Arbuscular mycorrhizal fungi (AMF) are soil microorganisms that establish symbiosis with more than 72% of land plants and have been reported to increase the production of bioactive compounds in various medicinal plants. Here, for the first time, we investigate whether AMF could modify the metabolites profiles of Anchusa officinalis (L.) and improve the secondary metabolites production (mainly alkannin/shikonin and their derivatives - A/Sd) of Alkanna tinctoria Tausch. Both plants belong to the Boraginaceae family and are well known to produce therapeutic metabolites. The thesis is divided into two main parts: 1) focus on A. officinalis studies. The effects of different AMF from the Glomeromycota IN vitro COllection (GINCO) are reported on the production of primary and secondary metabolites as well as plants’ exudates in the nutrient solution of the circulatory semi-hydroponic (S-H) cultivation system; 2) focus on A. tinctoria studies. A protocol for its mass production starting from in vitro shoot-tip explants is reported. Effects of two GINCO and two AMF isolated from the roots of wild-growing A. tinctoria are reported on the A/Sd production and target genes expression in the roots of plants growing in the S-H cultivation and pot systems. Our results confirm the role of specific AMF in modifying and enhancing the production of plants’ metabolites. The importance of screening procedures to select resistant and efficient AMF strain/s is highlighted, as well as the need for optimized growing systems to increase the production of metabolites. Our results also plead for deeper investigation into the mechanisms involved in the effects induced by AMF on the plants.