A. RT-qPCR of spxA2 in B. subtilis that produces SaiR. The wild-type (ORB8820) and spx mutant (ORB9050) cells were grown in LB. At OD600=0.3–0.4, cells were treated with NaOCl (final concentration of 2 mM), H2O2 (1 mM), or diamide (0.5 mM) for 10 min. RNA purification and cDNA preparation were previously described (Barendt et al., 2013). The fold-induction was shown as averages of biological triplicates with standard deviations after standardized with rpoB as described in Experimental procedures.
B. spxA2(−247/+268)-lacZ was measured in the wild-type strain in the absence (ORB8827) and presence (ORB8820) of the saiR gene. The lacZ expression was also measured in the strain lacking B. subtilis spx in the absence (ORB9049) and presence (ORB9050) of saiR.