FIG. 5.

Northern blot analysis of sigA (A) and sigB (B) transcripts in response to stress. RNA was extracted from log-phase (4 days) (left-hand panels) and stationary-phase (40 days) (right-hand panels) bacilli after exposure to different stress conditions described in Materials and Methods and subjected to Northern blot analysis. (C) The same blots were stripped and hybridized with the 16S rRNA-specific probe. (D) Densitometric analysis of sigB mRNA. Open bars, RNA from log-phase bacilli; filled bars, RNA from stationary-phase bacilli. The values shown are the averages of three independent experiments. Ctrl, control; EtOH, ethanol.