The genetics of flower development: from floral induction to ovule morphogenesis

Flower development consists of several phases. The first step is the transition from vegetative to reproductive development, regulated by floral induction. Later steps include the initiation of individual flowers, the determination of organ identity, and organ-specific differentiation. One of the major discoveries of plant biology is that the genetic network controlling flower development is highly conserved in two distantly related dicots, Arabidopsis thaliana and Antirrhinum majus, and probably in other species as well. Classical genetics has identified a sizable number of genes regulating flower development, and many of these regulatory genes have been cloned. This review summarizes recent advances in the understanding of the genetic control of floral induction and determination of flower-meristem identity, with the focus on Arabidopsis thaliana. In addition, recent work on ovule morphogenesis, a late process in flower development, is discussed.