Figure 8. The Δ42 mutant is not more susceptible to osmotic or oxidative stress.

(A) Growth of Δ42, ΔNAGGN and PA14 wild-type under osmotic stress in vitro. Cells were grown at 37°C in MinA medium supplemented with 0.5 M NaCl. Data represent the mean ± SE of 3 replicates. (B) The in planta growth defect of Δ42 is suppressed by trehalose but not betaine. See Figure 2 for experimental details. Data represent the mean ± SE of six replicate samples. (C) In vitro survival of PA14 wild-type, Δ42, and a PA14 zwf::MAR2xT7 mutant cultured for three days in MinA medium supplemented with various concentrations of paraquat (PQ). (D) Survival of PA14 wild-type and Δ42 in LB medium containing 1 M or 2 M hydrogen peroxide added directly to overnight cultures grown for 14 h (inoculum, zero time point on x axis). Cells were further incubated for 8 h at 37°C. 3 M H₂O₂ was a lethal dose. All experiments in Figure 8 were repeated at least two times.