Figure 4.

Effects of the Glu-204 and His-205 mutations on H₂O₂ sensing at low levels in VvOxyR2. The VvoxyR2 mutants containing plasmids expressing VvOxyR2 (E204A) (A), VvOxyR2 (H205A) (B), and VvOxyR2 (K203D) (C) were grown anaerobically to an A₆₀₀ of 0.3 and exposed to various concentrations of H₂O₂, as indicated, for 3 min. Total RNA isolation and quantitative real-time PCR analyses were performed as described previously. The Vvprx2 mRNA level under anaerobic conditions (H₂O₂ = 0) was set as 1. All data are presented as mean ± S.D. (error bars); n = 3.