Abstract
In order to understand the mechanism of vascular bundle formation in leaves, we have used rice plants in which vascular bundle formation occurs one-dimensionally at the base area of the leaf according to developmental program. Previously, we reported the commissural vein excessive1 (coe1) mutant that shows narrower intervals of commissural veins and predicted that COE1 encode a LRR-RK. In this work, we analyzed another knockout allele coe1-2 and indicated that this allele causes similar phenotype to that of coe1 but more severe phenotype. Genome search of Arabidopsis thaliana revealed a few homologous genes, and some of these promoters also conferred vascular bundle-specific expression. Based on results obtained so far, we will discuss on the role of COE1 in the initiation of vascular bundle differentiation.
