The TATA-box insertion in FUE increases Fe accumulation. A, XRF microtomography of tobacco leaves transformed with FUE:IRT1:GFP and FUI:IRT1:GFP. Bar color (blue to red) reflects the Fe contents (low to high). The SR-μXRF signals for the map were collected in 100-μm steps. The areas mapped for FUE:IRT transgenic lines 1, 3, and 5 were 600 μm × 600 μm, 600 μm × 600 μm, and 1,200 μm × 1,200 μm, respectively. The areas mapped for FUI:IRT transgenic lines 1, 5, and 8 were 1,000 μm × 1,000 μm, 600 μm × 600 μm, and 600 μm × 600 μm, respectively. B, Relative expression of GFP in transgenic tobacco. Error bars in B indicate sd of three biological replicates.