Gene fusion and functional diversification of genes facilitate thermophilic fungal adaptation to temperature change.

Thermomyces dupontii harbors two paralogs ( and ) in the gene cluster for the biosynthesis of prenylated indole alkaloids (PIAs) and correponding iron chelators with assigned as one protein containing a CYP like domain fused with a FAD-binding domain-containing oxidoreductase. Genetic manipulation and metabolic profile analysis indicated both and were involved in transforming simple PIAs to their corresponding iron chelators. Moreover, is responsible for bolstering simple PIAs to complex PIAs, and for reinforcing conjugating unsaturated systems in complex PIAs. Chemical investigation led to isolation and characterization of novel complex PIA metabolites with more oxidations. also contributed to forming the third iron-chelating core in iron chelators. A series of iron bioassays and infrastructure analysis revealed that lack of these genes caused strongly elevated Fe levels but attenuated Fe levels, together with abnormal mitochondria in mycelia and lipid droplets and vacuoles in conidia. Phenotype analysis revealed that and facilitated fungal colony pigments, conidial formation and germination via bolstering conidiophores and cell walls in response to temperature reduction.