Effects of the RHD3 first intron on gene expression. A through D, Five-day-old seedling roots harboring the H2-I (A), pBI121 (B) 35SIc (C), or H1Ic (D) construct and incubated with X-gluc for 16 h. Bars = 100 μm. E through H, Root phenotype of 5-day-old rhd3-3 seedlings harboring the 35S::RHD3 (E and F) or the 35SI::RHD3 (G and H) constructs. Bars = 200 μm. E and G, Mutant phenotypes. F and H, Partially rescued phenotypes.