Localization of AtMYB44 expression. A, Histochemical GUS assay. An approximately 3.0-kb fragment of the AtMYB44 promoter was fused to the GUS gene and transformed into Arabidopsis. Histochemical assays for GUS activity in transgenic plants were performed as described by . GUS staining patterns were confirmed by observing at least eight different transgenic lines. 1, Rosette leaf; 2, flower; 3, inflorescence; 4, floral nectar; 5, stamen; 6, carpel; 7, petal; 8, sepal. B, GUS activity in transgenic Arabidopsis seedlings grown on Murashige and Skoog medium. 1, One-week-old whole seedling; 2, root tip (1 week old); 3, paradermal section of the abaxial epidermis (200×) from 2-week-old plant. Scale bar = 20 μm. C, Subcellular localization of AtMYB44 protein. AtMYB44 cDNA was fused to GFP and the construct was expressed in transgenic Arabidopsis under the control of the CaMV 35S promoter. GFP fluorescence patterns were confirmed by observing at least five different transgenic lines under a confocal laser-scanning microscope. 1, GFP fluorescence; 2, differential interference contrast (DIC; optical microscopic image); 3, merged image (GFP + DIC); 4, GFP from 35S:GFP control plant. Scale bars = 20 μm for the images from the 35S:AtMYB44-GFP plant (1, 2, and 3) and 10 μm for that from the 35S:GFP plant (4), respectively.