FIG 2.
osaR overexpression downregulates fleQ and swimming motility. (A) The effect of OsaR on the transcriptional level of fleQ. The mRNA levels of fleQ were determined by qRT-PCR. (B) The effect of OsaR on the promoter activity of fleQ. WT strain (PAK19), osaR mutant (ΔosaR19), and osaR overexpressing strain (osaROE) were transformed with the reporter plasmid PfleQ-lacZ, followed by β-galactosidase assays when cultured to an OD600 of ∼0.6. (C) The effect of OsaR on swimming motility. Motility was detected on M63 glucose/CAA plates containing carbenicillin (left), and the diameters of the swimming zone were measured from three independent replicates (right). ns, not significant; ***, P < 0.001; ****, P < 0.0001, as determined by Student's t test. Error bars represent standard deviations.