HapX of <i>A</i>. <i>benhamiae</i> is important for transcription of iron regulatory genes during iron limitation.

<p>(A) Transcript levels of transcription factors HapX and SreA during iron starvation (-Fe) and iron-replete conditions (+Fe). (B) Transcript levels of the genes <i>cccA</i>, <i>hemA</i>, <i>lysF</i> and <i>cycA</i> during iron starvation (-Fe) and iron-replete conditions (+Fe). Transcript levels measured by quantitative RT-PCR analysis are presented relative to those of <i>A</i>. <i>benhamiae</i> wild type during iron-replete conditions. Data represent the means and standard deviations of three biological replicates. The differences between wild type and Δ<i>hapX</i> mutant were statistically significant during iron starvation (2way ANOVA; ** significant at P < 0.01, *** significant at P < 0.001).