Fig. 6
Accumulation of LOX-derived fatty acids hydroperoxides in TCDD-exposed Arabidopsis. a. Transcriptional fold changes of lipoxyganse encoding genes (LOXs) in whole plants after exposure to TCDD (0, 10, 50 and 100 ng L−1) for 6, 12, 24, 36, 48 and 60 days. For each gene, the transcript level was estimated by qRT-PCR as described in methods. b. Quantification of LOX genes expression in Arabidopsis tissues after treatment with indicated concentrations of TCDD for 36 days. Three measurements were taken in three cDNAs prepared from three individual plants for each TCDD-treatment. Different lowercase letters indicate significant differences in the expression for each LOX gene according to various concentrations of TCDD and control: a P < 0.05 (significant); b P < 0.01 (very significant). Asterisks indicate significant differences between the expression of LOXs genes according to each treatment: *P < 0.05 (significant); **P < 0.01 (very significant). c and d. UV-HPLC-separation of 9- or 13-HPOD and 9- or 13-HPOT extracted from TCDD-exposed Arabidopsis tissues at different stages of development. e, f, g and h. The four major hydroperoxide fatty acids (9-HPOD, 13-HPOD, 9-HPOT, and 13-HPOT) of Arabidopsis were extracted and quantified as described in methods. For each hydroperoxide, three measurements were taken in three individual plants. Data are mean values ± SD (n = 6). FW: fresh weight. Statistical significance of the data was evaluated by ANOVA analysis and Duncan’s multiple range test. Asterisks indicate significant differences in lipid peroxides according to the plant age compared to germination stage (6 days): *P < 0.05 (significant); **P < 0.01 (very significant)