A Fungal Transcription Factor Essential for Starch Degradation Regulates Primary Carbon and Nitrogen Metabolism and Amino Acid Biosynthesis

Purpose: The ∆col-26 mutant cannot utilize starch components and many other simple sugars efficiently. We employed RNA-seq based transcriptome profiling to reveal genes under the control of col-26. Method: We first obtained transcriptional data of Neurospora crassa WT on Vogel's minimal medium (VMM) without carbon source, on VMM with 2% sucrose, and on VMM with starch component, and transcriptional data of the ∆col-26 mutant on VMM with maltose or amylose. Results: We identified a starch-regulon of 322 genes and found that 255 of the starch-regulon were down regulated in in absence of col-26. We also found that genes with functions in primary carbon and nitrogen metabolism and amino acid biosynthesis were also down regulated in the mutant. Conclusion: Our data represents a systematic transcriptome profiling of filamentous fungi on different starch components and identify COL-26 as a critical regulator in both starch degradation and primary carbon and nitrogen regulation. mRNA profiles of cultures of WT and the ∆col-26 mutant after 4 hours of exposure to media of interest were generated by deep sequencing, in triplicate, using Illumina HiSeq 2000.