Different stress conditions affect the <i>C</i>. <i>crescentus</i> cell cycle at different stages.

<p>(a) Phase contrast microscopy images and flow cytometry profiles showing cell cycle phenotypes of wild type <i>C</i>. <i>crescentus</i> under different stress conditions. Fluorescence that equals one (1N) or two (2N) fully replicated chromosomes is indicated in each flow cytometry profile. Data of exponentially growing cells (no stress) are shown for comparison. Stress conditions were chosen at concentrations and time points when cells were still viable but growth rate was slowed (see also <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006522#pgen.1006522.s002" target="_blank">S2 Fig</a>) or, in the case of stationary phase and carbon starvation, when growth was arrested. Stationary phase was induced by continuous growth for 48 hours, carbon starvation was induced by growing cells in M2 0.02% glucose for 8 hours. Heat shock data are shown for cultures that have been exposed to 45°C for one hour or to 40°C for 6 hours. DNA damage was induced by treating cells for 6 hours with 3 μg/ml mitomycin C (MMC), oxidative stress by growing cells in the presence of 0.1 mM H₂O₂ for 1 hour. For the NaCl, sucrose and ethanol stress conditions data are shown for cells that were treated with 100 mM, 200 mM or 4%, respectively, for 6 hours. Phenotypes at low pH (pH 4.9) and high pH (pH 9.1) were monitored after 1 hour. (b) Box plots showing changes in cell area as a response to treatment with NaCl, EtOH or mild heat shock at different time points (upper panels) or at different concentrations / temperatures (lower panels). The number (n) of analyzed cells is indicated below each plot.