The miox4 message is present in flowers and leaves, tissues with high concentration of AsA. A, RNA expression of miox4 in leaf, flower, and root tissues of 6-week-old Arabidopsis wild-type plants. rRNA of the samples stained with ethidium bromide is shown as a loading control in the lower panel. B, Mean ascorbic acid content of the corresponding plant tissues (n = 3). Bars = one sd. L, Leaf; S, stem; F, flower; R, root; Si, silique.