XVI International Botanical Congess

The ariel development of plants is dependent upon the shoot apical meristem, commonly generating leaves, shoots or flowers. During the life cycle, the apical meristem passes through different phases, such as vegetative, inflorescence and floral. We have shown that these phases are linked by a common mechanism that responds to CEN and its homologues such as TFL1 of Arabidopsis. The CEN gene of Antirrhinum is normally only expressed in the inflorescence phase where it prevents conversion of the inflorescence meristem to a terminal flower. TFL1 acts during all phases of Arabidopsis development to delay each phase change transition. These phases are even further delayed by overexpression of TFL1 or CEN in Arabidopsis. Therefore, this mechanism of phase change appears to have been highly conserved over evolution.