A FILAMENTOUS FLOWER orthologue plays a key role in leaf patterning in opium poppy.

The plant-specific YABBY genes were initially defined by their roles in determining abaxial/adaxial cell fate in lateral organs of eudicots, and repressing meristematic genes in differentiating tissues such as leaves. In Arabidopsis thaliana FILAMENTOUS FLOWER (FIL) is also required for inflorescence and floral meristem establishment and flower development in a pathway involving the floral transition and identity genes. Here we describe the characterization of a FIL orthologue from the basal eudicot, Papaver somniferum (the opium poppy), and demonstrate a role for the gene in patterning the highly lobed leaf of the poppy.