Fig 5. AtrR is involved in adaptation to hypoxia.

(A) Growth test under normoxic and hypoxic conditions. The conidia of each strain were inoculated on GMM plate, and the plate was incubated in anaeropack system (a sealed pack) where initial concentration of oxygen was set at 2% (hypoxia condition). After 96 h, oxygen in the pack appeared to be completely consumed as estimated from no more growth of all colonies on the plate. The plate for normoxia was incubated in a regular incubator (21% oxygen) for 72 h. (B) Growth of Afs35-background strains under normoxic and hypoxic conditions. The 10 to 10⁴ conidia of each strain were inoculated on GMM plate, and the plate was incubated in anaeropack system (a sealed pack) for 48 h, where concentration of oxygen was maintained at 2 to 4% (moderate hypoxia condition). (C) Expression levels of erg3B, erg24A, erg25A, and cyp51A genes in response to oxygen limitation (O₂ limit.) were determined by real-time RT PCR method. The strains were cultivated in YGMM for 18 h. A half potion of the culture was transferred into a 50 mL tube with a screwed cap. The tube was closed with a cap carefully eliminating air, and was incubated for another 1 h. The expression levels of gene of interest were normalized with that of actin gene. Relative expression ratios against Af293 (WT before oxygen limitation) are shown. Error bars represent the standard deviations based on three independent replicates.