Fig. 2. Ubiquinone-9 levels in A. thaliana rosette leaves. A. thaliana seedlings were axenically fed for 24h with 0 (control), 2, 10, 125 and 250 μM of 4- hydroxybenzoate. Data represent the means of 5 biological replicates ± SE. P values from an analysis of variance between each mutant and the wild-type reference are indicated above the bars. Asterisks indicate significant differences between the control and the 4-hydroxybenzoate-fed plants as determined by variance analysis (P <α = 0.1).