FIG 1.

Acidic stress activates the expression of whiB3 in M. marinum but not in M. smegmatis. Transcriptional levels of the whiB3 gene in M. marinum (Mma) (A) and M. smegmatis (Msm) (B) at neutral or low pH (pH 6.8 and pH 4.5, respectively). RNA levels were first normalized to either the 16S rRNA (in M. marinum) or the sigA levels (in M. smegmatis), and the relative RNA levels at pH 6.8 in these strains were normalized to 1. Mean values with standard deviations from two independent tests in duplicates are shown. *, P < 0.05.