Sequential activation of two Dof transcription factor gene promoters during vascular development in Arabidopsis thaliana.

Plant-specific Dof transcription factors play various roles in plants. We show the strictly regulated activity of two Dof gene promoters during procambium formation, an early process for vascular development, in Arabidopsis thaliana (L.) Heynh. The AtDof2.4 promoter was active in procambial cells of leaf primordia, roots and embryos, whereas the AtDof5.8 promoter activity was specifically detectable in the cells of prospective veins in leaf primordia of seedlings and cotyledons of developing embryos, and the vascular tissue of developing flower buds. The AtDof5.8 promoter but not the AtDof2.4 promoter showed strong activity in advance of perceptible procambium formation. AtDof2.4 and AtDof5.8 might function in the early but different processes for vascular development.