Proteolytic activity and gene expression of Rhl-dependent reporters in various genotypes and conditions. (A) Proteolytic activity was measured using an elastin-congo red assay for each of the genotypes (methods). (B) GFP expression average of single cells as measured using a PlasB-GFP reporter during growth in casein medium. Results are shown for three genotypes; ΔlasR (blue, overlapped by red), ΔlasR;psdR- (red) and ΔlasR;psdR-;mexT- (orange). Results were obtained using flow cytometry. (C). GFP per optical density as a function of time of GFP transcriptional reporters for lasB (top panel), rhlA (middle panel) and rhlI (bottom panel). Results in each panel are shown for four genotypes; mexT+ (light blue), ΔlasR (red), mexT- (orange) and ΔlasR; mexT- (magenta). Error bars represent standard error of three or more independent repeats on different days. Exact genotypes are provided in Supp. Tables S1,S2. * – p-value<0.05, ** – p-value<2×10-3.