FIG 7.

troA expression in the WT and ΔtroR strains in response to various metals. The WT and ΔtroR strains were grown in TSBS to an OD₆₀₀ of 0.6 and treated for 15 min with 2 mM Fe(II), 2 mM Mn, 50 μM Zn, 1 mM Cu, 1 mM Co, 1 mM Ni, 2 mM Ca, 2 mM Mg, or deionized water. RNA was isolated to perform reverse transcription-quantitative PCR analysis. The data shown are the means ± SDs from three biological triplicates. troA expression in the WT strain in response to the metals was analyzed by one-way analysis of variance with Bonferroni’s posttest. Two-way analysis of variance with Bonferroni’s posttest was used for comparison of troA expression in the ΔtroR mutant with that in the WT strain. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, no significant difference.