Constitutive expression of miox4 in Arabidopsis increases the ascorbic acid content of the leaves. A, RNA expression of miox4 in control (labeled as C, pCAMBIA1380), and three homozygous transgenic lines, numbered L1 to L3. rRNA of the samples stained with ethidium bromide is shown as a loading control in the lower panel. B, Mean ascorbic acid content in the leaf extract of the corresponding control (C) and transgenic lines L1 to L3 (n = 3). Bars = one sd.