Regulatory Networks Governing Methionine Catabolism into Volatile Organic Sulfur-Containing Compounds in Clonostachys <i>rosea</i>

Methionine shuttles organic nitrogen and plays a central role in nitrogen metabolism. Exogenous Met strongly induces the expression of ARO8-2 and PDC , represses the expression of STR3 , and generates volatile organic sulfur-containing compounds via the Ehrlich and demethiolation pathways. In this study, we used genetic, bioinformatic, and metabolite-based analyses to confirm that transcriptional control of the aminotransferase gene ARO8-2 , the decarboxylase gene PDC , and the demethiolase gene STR3 modulates Met catabolism into volatile organic sulfur-containing compounds. Importantly, we found that, in addition to the Ehrlich pathway, the demethiolation pathway was regulated by a nitrogen catabolite repression-sensitive regulatory pathway that controlled the transcription of genes required to catabolize poor nitrogen sources. This work significantly advances our understanding of nitrogen catabolite repression-sensitive transcriptional regulation of sulfur-containing amino acid catabolism and provides a basis for engineering Met catabolism pathways for the production of fuel and valuable flavor alcohols.