FLORAL MERISTEMS TO FLORAL ORGANS - GENES-CONTROLLING EARLY EVENTS INARABIDOPSIS FLOWER DEVELOPMENT

Molecular and genetic studies show that the underlying mechanisms cont rolling flower development are largely conserved in distantly related dicotyledonous plant species. These studies have identified early-acti ng genes that promote the formation of floral meristems and later-acti ng genes that determine the fate of floral organ primordia. The floral meristem identity genes lie at the top of a regulatory hierarchy that leads to the activation of the organ identity genes. Subsequent regul atory interactions between the organ identity genes restrict their dom ains of activity. The resulting spatial domains of gene activity allow cells within the floral meristem to assess their position and, hence, to differentiate into the appropriate organ type.