Epigenetic manipulation for secondary metabolite activation in endophytic fungi: current progress and future directions

Fungal endophytes have emerged as a promising source of secondary metabolites with significant potential for various applications in the field of biomedicine. The biosynthetic gene clusters of endophytic fungi are responsible for encoding several enzymes and transcriptional factors that are involved in the biosynthesis of secondary metabolites. The investigation of fungal metabolic potential at genetic level faces certain challenges, including the synthesis of appropriate amounts of chemicals, and loss of the ability of fungal endophytes to produce secondary metabolites in an artificial culture medium. Therefore, there is a need to delve deeper into the field of fungal genomics and transcriptomics to explore the potential of fungal endophytes in generating secondary metabolites governed by biosynthetic gene clusters. The silent biosynthetic gene clusters can be activated by modulating the chromatin structure using chemical compounds. Epigenetic modification plays a significant role by inducing cryptic gene responsible for the production of secondary metabolites using DNA methyl transferase and histone deacetylase. CRISPR-Cas9-based genome editing emerges an effective tool to enhance the production of desired metabolites by modulating gene expression. This review primarily focuses on the significance of epigenetic elicitors and their capacity to boost the production of secondary metabolites from endophytes. This article holds the potential to rejuvenate the drug discovery pipeline by introducing new chemical compounds.