FIG 4 .
(A to C) SalA dominated the regulation of genes involved in siderophore biosynthesis (A) and iron-sulfur homeostasis (B), whereas GacS independently regulated genes involved in an oxidative stress response (C). The heat maps display the fold change in gene expression in the gacS and salA deletion mutants relative to gene expression in strain B728a. All genes that were altered >10-fold are shown with the same intensity as those altered 10-fold. Numbers to the left are the Psyr locus number, and treatments are shown on the top, with abbreviations as defined in the legend to Fig. 1. σECF, extracytoplasmic function sigma factor.