Differential induction of secondary metabolite profiles in endophyte fungi by the addition of epigenetic modifiers

Fungal endophytes are known to produce a wide variety of secondary metabolites (SMs) involved in their adaptation and survival within higher plants. The plant-microbe interaction may influence the expression of some biosynthetic pathways, otherwise cryptic in these fungi when grown outside its natural environment. Adding epigenetic small-molecule modifiers of Histone Deacetylase (HDAC) and DNA methyltransferase (DNMT) activities in fungal endophyte fermentations, may induce, among others, the expression of these biosynthetic pathways that occur naturally in plant-microbe interactions.

The addition of these small-molecule epigenetic elicitors since the inocula of several fungi in our study, determined a more consistent activation of fungal endophytes silent biosynthetic pathways, compared to its only addition during their production fermentation. uHPLC analyses showed these differential types of responses, including profiles with few changes in their metabolite production, higher amounts of some or all SMs, or few changes but with new SMs present, proving that the use of these epigenetic modifiers can ensure an extensive generation of new SMs, previously unknown to be produced by this group of endophyte fungi, in laboratory conditions.