Abstract
Leaves develop as flat lateral organs from a shoot apical meristem. The establishment of polarity along three-dimensional axes, namely, proximal-distal, medial-lateral and adaxial-abaxial, is crucial for the growth of normal leaves. ASYMMETRIC LEAVES2 (AS2) and AS1 are involved in repression of both the class 1 KNOX genes and leaf abaxial determinants (ETTIN/ARF3, KANADI2 and YABBY5). AS1 and AS2 may function as key regulatory genes for the establishment of adaxial cell fate in leaves. In addition, it has been reported that several ribosomal protein genes and chromatin remodeling factor genes are also required for the establishment of adaxial-abaxial polarity of leaves. However, the roles of these genes in leaf development have still unknown. We have taken a chemical and genetic approach with the goal of understanding the establishment of adaxial-abaxial polarity of leaves. We identified several small molecules that inhibited the formation of the leaves in as2-1 and as1-1 plants. We will discuss modes of action of these small molecules.
