Endophytic Fungi for a Sustainable Production of Major Plant Bioactive Compounds

Abstract

Plants are the major resource for obtaining biologically active constituents. However, the heavy demand for these bioactives and its derivatives cannot be met by the natural sources, which is the major drawback. Alternatives, including the use of endophytes have to be utilized for the mass production of these bioactive agents. ‘Endophytes’ can be defined as organisms, which have the capability to form colonisation inside the plant tissue. Almost all plants harbour one or other bacteria or fungi in their tissues. Fungal endophytes belong to Ascomycetes and anamorphic fungi. They are generally associated with the plant tissues with or without generating harmful effects to the host. Endophytes are sometimes beneficial to the host plants by interfering with the pathogenic organisms. The interaction of fungal endophytes with host plants is one of the best environmentally friendly approaches in the augmented production of plant metabolites. The fungal endophytes have a broad level of applications in medicine, agriculture, pharmacy and industries by enhancing the host plant’s anticancer, antimicrobial and cytotoxic potentials by stimulation of the biosynthesis of major phytoconstituents. The major biotechnological application of fungal endophytes is their capability to augment the production of anticancer principles in medicinal plants. The major compounds in chemotherapeutic field include vinblastine, vincristine, podophyllotoxin, paclitaxel, docetaxel, camptothecin, topotecan, curcumin and silymarin that can be enhanced by fungal endophytes. The major antimicrobial compounds include terpenoids, essential oils, phenolics, polyphenols and alkaloids. The enhancement of active principles responsible for the antiproliferative potential by the fungal endophytes has been reported from different plant sources. Due to overexploitation, most of the plants with medicinal and industrial importance have been declared as endangered or vulnerable. In the future, endophytic fungi could be a suitable alternative for the enhanced biosynthesis of bioactives from plants, which in turn mitigate the overexploitation of economically important plants.