FIG. 4.
The ΔrpoE mutant of X. campestris pv. campestris is sensitive to heat and ethanol. (A) Heat sensitivities of X. campestris pv. campestris WT and mutant strains containing no plasmid, control plasmid p917, or σE-overexpressing plasmid p917-rpoE. Serial 10-fold dilutions of late-exponential-phase bacteria were spotted on plates and incubated at 35°C for 72 h. Each experiment was repeated three times. (B) Growth curve of X. campestris pv. campestris WT and mutant strains in the presence of 1.5% ethanol. Cells were precultured in MOKA medium overnight and then diluted to an OD600 of 0.05 in MOKA medium containing 1.5% ethanol. One representative experiment out of three independent replicates is shown.