How promising are endophytic fungi as alternative sources of plant secondary metabolites

In this article the authors discusses the use of endophytic fungi as substitute of plant secondary metabolites. It states that endophytic fungi exist internally in plants and enhance the plants' ability to tolerate abiotic and biotic stresses. Endophytic fungi if cultured outside their host can produce secondary metabolites such as anti-cancer, anti-fungal, anti-diabetic and immunosuppressant compounds.