Figure 4

qRT-PCR shows transcription of the major vegetative sigma factor hrdB is repressed following induction of ppGpp synthesis, while the alternative ECF sigma factor encoded by SCO4005 is induced. In each biological replicate experiment, R1-R3, using strain M653 [ΔrelA tipAp::relA(1.46 kb)] or the control strain M667 [ΔrelA tipAp], lane 1 corresponds to the pre-induction sample (0 minutes) and lanes 2 and 3 correspond to the samples taken 60 minutes after induction or non-induction with thiostrepton, respectively. The average of three qRT-PCR determinations is shown, and standard deviations are marked with error bars.