The expression of oxidative stress marker genes in
lines is upregulated. Mature leaves of 4-week old soil grown wild-type Col-0 and max2 plants were collected at indicated time points after P. syringae DC3000 infection and RNA was extracted to check the relative expression of oxidative stress marker gene GRX480 after 350 ppb for 6 h ozone exposure (A) and after pathogen infection (B). Another oxidative stress marker gene GST1
(C) and auxin-responsive gene HAT2
(D) also checked after pathogen infection. For this analysis, 3 plants/line and 3 leaves/plant were used in each time point of infection and ozonation. Each expression analysis is based on a minimum of 3 independent experiments. Asterisks indicate significant differences, as determined by Student’s t-test (*P < 0.05; **P < 0.01; two-tailed t test).