Global regulation of fungal secondary metabolism in by the transcription factor Ypr1, as revealed by transcriptome analysis.

Rut-C-30 is a well-known robust producer of cellulolytic enzymes, which are used to degrade lignocellulosic biomass for the sustainable production of biofuels and biochemicals. However, studies of its secondary metabolism and regulation remain scarce. Ypr1 was previously described as a regulator of the biosynthesis of the yellow pigment sorbicillin (a bioactive agent with great pharmaceutical interest) in and several other fungi. However, the manner in which this regulator affects global gene transcription has not been explored. In this study, we report the effect of Ypr1 on the regulation of both the secondary and primary metabolism of Rut-C30. A global gene transcription profile was obtained using a comparative transcriptomic analysis of the wild-type strain Rut-C-30 and its deletion mutant. The results of this analysis suggest that, in addition to its role in regulating sorbicillin and the major extracellular (hemi)cellulases, Ypr1 also affects the transcription of genes encoding several other secondary metabolites. Although the primary metabolism of ∆ became less active compared with that of Rut-C-30, several gene clusters involved in its secondary metabolism were activated, such as the gene clusters for the biosynthesis of specific polyketides and non-ribosomal peptides, together with the "sorbicillinoid-cellulase" super cluster, indicating that specific secondary metabolites and cellulases may be co-regulated in Rut-C-30. The results presented in this study may benefit the development of genetic engineering strategies for the production of sorbicillin by Rut-C-30, and provide insights for enhancing sorbicillin production in other filamentous fungal producers.