Figure 3.

Hydrogen peroxide production and activities of selected antioxidant enzymes in 4-week-old wild-type and mutant plants, determined for non-treated plants and 12, 24, 48, and 96 h after UV-C exposure (100 mJ cm⁻²). (A) H₂O₂, hydrogen peroxide content; (B) 3,3’diaminobenzidine (DAB) staining showing H₂O₂ production; (C) SOD, superoxide dismutase activity; (D) CAT, catalase activity; (E) APX, ascorbate peroxidase activity. Pictures show representative images selected from five different leaves stained per genotype and per time point. Values are means (±SD) of 9–12 plants per genotype and time point from at least two independent experiments (n = 9–12). Asterisks indicate significant differences from the wild type, according to the Tukey HSD test at the level of p < 0.05 (*), p < 0.005 (**), or p < 0.001 (***).