Abstract
The network pattern of the vascular tissue is determined when the pattern of the precursor prepro/procambium is determined. However, the molecular mechanism as to how the cell fate to be the prepro/procambium is given to some undifferentiated cells, but not to the other is still largely unknown. Toward understanding the mechanisms of formation of leaf-venation pattern, we have isolated and analyzed Arabidopsis mutants defective in formation of leaf veins. NO VEIN (NOV) and 621C-27 genes were identified as they were necessary for formation of the normal leaf-venation pattern. We will show that NOV and 621C-27 are required for formation of the normal prepro/procambial pattern in leaves and that NOV is required for formation of developmentally regulated auxin-distribution pattern both in the leaf and in the embryo. Roles of NOV and 621C-27 in vascular development will be discussed.
