Fig. 6.

Effects of an irr mutation on iron-dependent expression of frcB mRNA. mRNAs from cells of the parent strain or the irr mutant grown in medium supplemented with no added iron (−) or with 12 μM FeCl₃ (+) were analyzed by quantitative real-time PCR (qPCR). The data are expressed as the relative starting quantity (SQ) of the mRNA normalized (norm) to the housekeeping gene gapA, and the values are presented as the averages plus standard deviations (error bars) of three replicate samples. pyoR was used for comparison.