Heterochromatin protein 1 regulates alkaloid biosynthesis and the mutualistic symbiotic interaction between Epichloë festucae and its host Lolium perenne

Genes for the synthesis of ergot alkaloid and indole-diterpene bioprotective metabolites are organised as clusters in the sub-telomeric regions of the genome of Epichloë festucae, a fungal symbiont of Lolium perenne. These genes are highly expressed in planta but not expressed in axenic culture. We have shown that the levels of histone H3 lysine 9 and lysine 27 trimethylation are reduced at these loci in planta compared to axenic culture (Chujo & Scott 2014). More recently we have investigated the role of E. festucae HepA, a homolog of Heterochromatin Protein 1, in regulating expression of these alkaloid cluster genes and establishment of a mutualistic symbiotic interaction.