Evolutionary relics dominate the small number of secondary metabolism genes in the hemibiotrophic fungus Dothistroma septosporum.

摘要: Fungal secondary metabolites have important functions for the fungi that produce them, such as roles in virulence and competition. The hemibiotrophic pine needle pathogen Dothistroma septosporum has one of lowest complements metabolite (SM) backbone genes plant pathogenic fungi, indicating this fungus produces a limited range SMs. Amongst these SMs is dothistromin, well-characterised polyketide toxin factor required expansion disease lesions blight disease. Dothistromin are dispersed across six loci on chromosome, rather than being clustered most SM genes. We explored other D. septosporum to determine if they associated with gene clusters, predict what their likely products might be. Of nine functional genome, only four were expressed under planta culture conditions, which was dothistromin PKS gene. three genes, knockout studies suggested DsPks1 DsPks2 not attempts squalestatin-like product successful. However preliminary evidence DsNps3, be highly early stage disease, appears factor. Thus, despite small number D. septosporum, them appear poorly or dispensable planta. This work contributes growing body many fungal clusters non-functional may evolutionary relics.