FIG. 3.

Relative levels of dspE, hrpA, and hrpL mRNA in wild-type Ech3937 and iaaM mutant Ech138 grown for 12 h in a minimal medium. The amount of mRNA was examined by a qRT-PCR assay using the Real Master Mix (Eppendorf, Westbury, NY) in different samples. Reactions were run, and data were collected with the Opticon 2 system (Bio-Rad). The rplU gene was used as the internal control to normalize the cDNA input of each sample. Three replicates were used in this experiment, and the Student t test P value is less than 0.05.