Extended Data Fig. 7: (p)ppGpp and c-di-GMP control growth on glucose by balancing cellular redox state.
(a) Relative levels of radicals as measured by DCF fluorescence intensity in the strains indicated. Fluorescence was scored in exponentially growing cells in M2X (left bar) or in M2X supplemented with 10 mM ascorbic acid (right bar). Dashed lines indicate the levels of DCF fluorescence measured in Caulobacter wild type treated with 10 mM ascorbic acid (green) or untreated (black). (b–e) Growth of Caulobacter wild type and indicated mutant strains. Cells were diluted from cultures growing exponentially in PYE to fresh M2G or M2X with or without 10 mM ascorbic acid as indicated. In panels (a-e), data represent the mean of n = 3 biological replicates ± SD. (f) Flow cytometry analysis of Caulobacter wild type and mutant cells grown on M2X. Cells were sampled after growth in M2X for 15 h as indicated in (d) and (e) and samples were incubated with RSG for 20 min before FACS analysis. (g) Caulobacter cell cycle progression is affected by (p)ppGpp and SmbA. The optical density of synchronized populations of wild type and mutant strains was scored during one cell cycle as indicated. (h) Immunoblot analysis of synchronized populations indicated in (g) using polyclonal anti-CtrA antisera. CtrA protein levels are used as a marker for cell cycle progression (indicated for Caulobacter wild type above panels in g and h). Similar results were obtained in three independent experiments.
