Effect of autoregulation on mar-sox-rob regulon activation in the absence of genetic cross talk. Activation of the marRAB (A), soxS (B), and rob (C) promoters during induction with 5 mM salicylate, 50 μM paraquat, and 5 mM decanoate, respectively. Strains used were CR935 and CR936 (A), CR939 and CR940 (B), and CR934 and CR935 (C). A.U., absorbance units.