Transposon induced chimeras show that floricaula, a meristem identity gene, acts non-autonomously between cell layers.

Flower meristems comprise several distinct cell layers. To understand the role of cell interactions between and within these layers, we have generated plants chimeric for a key floral homeotic gene, floricaula (flo). These chimeras arose in Antirrhinum by excision of a transposon, restoring flo gene function. Activity of flo in a subset of cell layers gives fertile flowers with an abnormal morphology. This shows that flo can act non-autonomously between layers, although some aspects of its function are impaired. In addition, we show that flo exhibits some cell-autonomy within layers.