Expression patterns of the AtMTAN gene. A, RNA gel-blot analysis. Each lane was loaded with 10 μg of total RNA isolated from various organs of 5-week-old Arabidopsis plants: root (RT), rosette leaf (RL), stem (ST), cauline leaf (CL), and flower (FL). B, Histochemical GUS assay of AtMTAN promoter-GUS transgenic plants. I, Three-day-old seedling; II, 1-week-old seedling; III, 2-week-old seedling; IV, flower; V, anther; VI, pistil; VII, silique.