Fig. 5. Improved oxidative stress tolerance in transgenic tobacco plants overexpressing a non-ancient CKX gene.

a,b More dead tissues were observed in WT (left) than 35S:AtCKX2-overexpressing (CKX2-10, right) tobacco plants under oxidative stress for 5 days. c Lower catalase (CAT) enzyme activities were observed in the leaves of WT plants than in the leaves of CKX2-10 plants under oxidative stress for 36 h. The error bars indicate SEM values (n = 3 biological replicates), and asterisks indicate significant differences between WT and transgenic plants (** for p < 0.01). d, e More H₂O₂ accumulation was observed in WT leaves (upper) than in CKX2-10 leaves (lower) under oxidative stress for 36 h (d) or under drought treatment (e; see Fig. S7) after 14 days.