Figure 4.

Overexpression of hapX partly restores the conidiation defect of the tptA deficient strain in low iron conditions. (a) Relative RNA expression of hapX, sreA and tptA in the indicated strains cultured in MM or MM-Fe broth in the presence of 30 μM ThPP. (b) Compared to WT, lack of tptA results in decreased production of TAFC. TAFC was quantified by reversed-phase HPLC analysis from supernatants of cultures grown in MM-Fe broth with 30 μM ThPP for 24 h. TAFC production was normalized to biomass and WT production. (c) Colony morphology comparison for the indicated strains grown on MM media with or without 50 μM BPS in the presence of 30 μM ThPP at 37°C for 48 h. Data are presented as the means ± SD from three independent replicates. “*” or “**” represent significant differences at P < 0.05 and P < 0.01, respectively, according to t-test.