Figure 7.

The msn2Δ and msn4Δ mutations are epistatic to the siw14Δ mutation. A, WT, siw14Δ, msn2Δ, and msn4Δ single mutant, and the msn2Δ siw14Δ and msn4Δ siw14Δ double mutant strains were grown overnight in YPD and normalized to OD₆₀₀ of 0.2 in YPD medium. Cells were grown for 30 min and treated with 2 and 5 mm hydrogen peroxide for 3 h (61). Cells were serially diluted 10-fold, plated on YPD medium, and incubated at 30 °C for 2 days. B, strains were grown and prepared as described above; however, cells were treated with 2, 4, and 7 mm hydrogen peroxide. Instead of spotting, 20 μl of appropriately diluted sample were spread onto YPD plates. Colony-forming units were determined, and the percent survival was calculated (cfu treated/cfu untreated, ×100). Bars represent the average of 9 biological replicates over 3 assays. Error bars represent mean ± S.D. C, expression of CTT1 measured by RT-qPCR. Cells were grown as described in the legend to Fig. 3. Values were normalized to UBC6 and to the WT grown in YPD. The graph shows the mean from triplicate samples (biological replicates) and error bars represent mean ± S.D. Significance, **, p ≤ 0.01; *, p ≤ 0.05; n.s., not significant.