Roles of<i>CmFL</i>,<i>CmAFL1</i>, and<i>CmSOC1</i>in the transition from vegetative to reproductive growth in<i>Chrysanthemum morifolium</i>Ramat.

Abstract

SummaryThe transition from vegetative to reproductive growth is marked by the termination of vegetative development and adoption of a floral identity by the shoot apical meristem. This process is called the floral transition. To elucidate the molecular determinants involved in this process in chrysanthemum (Chrysanthemum morifolium Ramat.), we isolated the following three floral identity and/or integrator genes from plants: CmFL, a homologue of FLORICAULA (FLO)/LEAFY (LFY); CmAFL1, a member of the APETALA1 (AP1)/FRUITFULL (FUL) sub-family; and CmSOC1, a member of the SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) sub-family. Up-regulated expression of CmFL in Arabidopsis resulted in an early-flowering phenotype. Our data show significant up-regulation of expression of all three of the above-mentioned genes and a strong correlation between the floral transition and gene expression under three different photoperiodic conditions. This study strongly suggests that CmFL, CmAFL1, and CmSOC1 are involved in the transition from vegetative to reproductive growth, and are activated co-ordinately after the floral transition in early-developing inflorescences in chrysanthemum.