Epigenetic-based developments in the field of plant endophytic fungi
Shubhpriya Gupta, Manoj G. Kulkarni, James F. White, Johannes Van Staden
Abstract
The valuable bioactive compounds produced by endophytic fungi hold huge potential, which may be utilized by pharmaceutical, agriculture or food industries. However, it has been observed that the genes responsible for the production of bioactive metabolites from fungal endophytes are not expressed in axenic cultures. The defined media used for the culture of fungal endophytes do not mimic nutrients available in their native hosts. Due to the lack of host stimulus in culture media, many genes encoding biosynthetic pathways become silent, thus limiting their capacity for the production of metabolites. These silent biosynthetic pathways of novel bioactive secondary molecules can be induced by the use of epigenetic modifiers. The epigenetic modulation can greatly induce endophytic fungi-derived bioactive metabolites. The chemical epigenetic methods are being developed for obtaining secondary metabolites from fungal endophyte cultures. The treatment of fungal endophytes with epigenetic modifiers such as DNA methyltransferase (DNMT) inhibitors and/or histone deacetylase (HDAC) inhibitors might be a favourable approach to trigger the biosynthetic pathways of bioactive metabolites that are quiescent under laboratory conditions. In addition, endophytic fungi are also known to modify plant gene expression and physical composition by causing epigenetic changes in the host. The use of epigenetic modifiers may boost our capacities to screen for medicinal compounds in plants and improve plant performance in changing climate conditions.