qRT-PCR revealing iron-dependent
sreA and
hapX transcript abundance. Transcript levels of
hapX and
sreA were determined during iron starvation (−Fe), iron sufficiency (+Fe, 0.03 mM), iron excess (hFe, 3 mM) and after a 1-h shift from iron starvation to iron sufficiency (sFe) and normalized to that of γ-actin (AFUA_6G04740) using the
method. Data represent the mean ± SD of two biological and three PCR technical replicates and are presented relative to the transcript levels during iron sufficiency. All differences found are statistically significant with exception of the
hapX transcript level during iron sufficiency compared to high-iron conditions (two-tailed, unpaired
t-test;
P < 0.05).