Fig 4. Expression analysis of iron uptake genes in the T. marneffei mutants under different iron concentrations.

T. marneffei wild type, ΔacuK and ΔacuM strains were grown under various iron concentrations, in which 10, 100 and 1000 indicate micromolar concentrations of ferric chloride. The qRT-PCR was used to determine the fold-change of (A) sreA, (B) hapX, (C) ftrA and (D) fetC gene transcripts. Expression was compared to the wild-type strain under low iron concentration of 10 μM and the experiments were performed in triplicates. Error bars indicate standard deviation. Statistical analysis was performed using unpaired-t-test (GraphPad Prism version 7.00 for Windows). Statistically significant values (ns = non-significant, P>0.05, * P≤ 0.05, ** P≤ 0.01, *** P≤ 0.001, **** P≤ 0.0001) are indicated.