FIG 3.

Effect of H₂O₂ on S. meliloti mutants with complete deletions of alternative sigma factors. Survival rates were determined after 30 min of exposure to H₂O₂ of S. meliloti strains deleted for alternative sigma factors implicated in the response to H₂O₂. Survival was normalized to wild-type CL150 survival (10.3% ± 1.6%). Error bars indicate standard deviations; *, P ≤ 0.05. Experiments were performed in triplicate; two other independent experiments were performed with comparable results.