Prime editing for precise genome engineering and modulation of fungal metabolism

Prime editing has not been established in filamentous fungi, which are major ecological contributors and industrial hosts with vast biosynthetic capacity. Here we develop fPE7max, a prime editing platform optimized for fungi, which supports different edit types, including base substitutions and defined small insertions or deletions, with an average editing efficiency approaching 90%, across diverse genomic loci and species. fPE7max further enables larger insertions of up to 1 kb and deletions of up to 10 kb. We perturb upstream open reading frames in the pleiotropic regulator gene, laeA, to modulate metabolic output across multiple fungal species. Metabolomic profiling reveals activation of previously lowly biosynthetic pathways, leading to the identification of 18 metabolites, including 8, to our knowledge, previously unreported structures, 3 of which with cytotoxic activity. These results establish fPE7max as an efficient platform for genome engineering in filamentous fungi and show upstream open reading frame editing as a strategy for modulating endogenous regulatory networks and accessing the fungal chemical repertoire.