Gene expression of Grx4 regulated strains in the Ustilago maydis FB2 background

Gene expression of FB2 wt in minimal medium with 2 percent arabinose or glucose after 24h of growth was compared with the conditional promoter regulated strain Pcrg1:grx4 (#55). Glucose is a repressor of this promoter while arabinose acts as inducer. Grx4 was initially pre-depleted during growth on MM with glucose over night. Afterwards cells were transferred to MM with either glucose or arabinose and cells were collected after 24h. 3 biological repeats were performed for each strain and each condition. Cells were flash frozen and used to isolate total RNA. RNA sequencing was done by Genewiz. DEG's between wt and mutant for the different conditions were obtained. Iron regulated genes such as the high affinity uptake system and the siderophore system of Ustilago maydis were repressed in the Pcrg1:grx4 (#55) strain when grown in glucose. Expression of these genes were similar for wt and the conditional strain when grown in arabinose. Grx4 was identified as an essential gene in Ustilago maydis which regulates the iron regulon and related genes. Overall design: A conditional mutant of the Grx4 gene was constructed in Ustilago maydis and grown in minimal media with either 2% arabinose or 2% glucose. 3 biological replicates were included. Samples were treated for 24 hours before isolating RNA and analysing differences in gene expression.