Abstract
In dicot plants, leaf primodia are derived from the shoot apical meristem and develop flat and symmetrical leaf blade. The establishment of adaxial-abaxial polarity is required for lateral expansion of leaf blade. In Arabidopsis thaliana, class III HD-ZIP genes, YABBY and KANADI genes, microRNAs and trans-acting siRNAs regulate leaf development through distinct pathways. The as2-1 mutation causes pleiotropic phenotypes in leaves. Our previous study suggest that AS2, directly or indirectly, represses the expressions of class 1 KNOX genes and abaxial genes, ETTIN, KANADI2 and YABBY5. To identify new components that function together with AS2 in leaf development, we analyzed enhancers of the as2-1 mutant. east1-1 as2-1 and east1-2 as2-1 mutants formed filament-like leaves associated with defect in the adaxial-abaxial leaf polarity. east1-1 also showed weak defects in leaf venation patterns. Expression analysis revealed that mRNA levels of class1 KNOX genes and abaxial genes were increased in east1-1 as2-1. We will also present genetic analysis using as2-1 and other elongata or other enhancer mutants to discuss genetic relationship among them.
