Ricerc@Sapienza

Both saprophytic soil fungi and those living as endophytes have the potentiality to shape and modulate the stress tolerance in plants. These fungi can operate by eliciting or increasing defence responses in the plant or indirectly through complex mechanisms of competition for substrates. This aspect assumes an even greater relevance when these metabolites have a pharmacological potential.
The objective of the proposal is to develop a strategy for the sustainable cultivation of the medicinal plant Hypericum perforatum (L.) through the use of multifunctional soil bioinoculants and the application of water-soluble fungal elicitors to the aerial organs.
The treatments will be aimed to: i) promote the plant growth; ii) enhance the biosynthesis of bioactive secondary metabolites, including hypericin, hyperforin, essential oils, flavonoids and xanthones; iii) induce resistance to disease; iv) increase the antifungal activity of root and shoot extracts; v) reduce the use of chemical fertilisers and synthetic compounds both against plant and human pathogens.
Bioinocula will be chosen among fungal species already known for their growth-promoting activity (Minimedusa polyspora) and for living in association with H. perforatum as endophytic fungi (e.g. Chaetomium globosum).
H. perforatum aerial parts will be treated by nebulization with chitosan oligosaccharides (COS), already known as growth-promoting substances and for their elicitor power on xanthone biosynthesis in the roots.
Antifungal tests will be carried out against two of the main H. perforatum fungal pathogens (Colletotrichum gloeosporioides and Phomopsis sp.), in order to investigate disease resistance as induced by the selected saprotrophic fungi and the treatment with COS.
The antimicrobial activity of extracts obtained from H. perforatum plants treated with saprotrophic fungi and/or COS will be evaluated on human fungal pathogens, such as Candida species and dermatophytes.