Fig. 3.
ILA enhances superoxide radicals in leaves. NBT staining in leaves of 2-week-old seedlings was assessed as a semi-quantitative measurement of O2− formation (compare Fig. 4A, B). (A) NBT staining 48 h after treatment with 250 µM ILA, 500 µM ILA, 100 µM SA, 500 µM SA, or the combination of 100 µM SA + 250 µM ILA. Means ±SE; n=9. Significant differences (Padj<0.05) are indicated by letters according to one-way ANOVA. (B) NBT staining in 2-week-old NahG sid2 (n=21) and wild type (WT; n=15) seedlings 48 h after treatment with 500 µM ILA. Means ±SE; differences between treated or untreated plants were analysed by Welch’s two sample t-test. (C) NBT staining detected in leaves of ugt76b1, wild type (WT) and UGT76B1 overexpressor (OE). Means ±SE; n=20–23. Significant differences (Padj<0.05) are indicated by letters according to one-way ANOVA. The experiments were independently repeated three times with similar results. (D–F) Representative images of NBT staining of leaves of the indicated genotypes and treatments, which were analysed in (A), (B), and (C), respectively.