title: Evolutionary conservation of the FLOWERING LOCUS C-mediated vernalization response: evidence from the sugar beet (Beta vulgaris).
abstract: In many plant species, exposure to a prolonged period of cold during the winter promotes flowering in the spring, a process termed vernalization. In Arabidopsis thaliana, the vernalization requirement of winter-annual ecotypes is caused by the MADS-box gene FLOWERING LOCUS C (FLC), which is a repressor of flowering. During the vernalization process, FLC is downregulated by alteration of its chromatin structure, thereby permitting flowering to occur. In wheat, a vernalization requirement is imposed by a different repressor of flowering, suggesting that some components of the regulatory network controlling the vernalization response differ between monocots and dicots. The extent to which the molecular mechanisms underlying vernalization have been conserved during the diversification of the angiosperms is not well understood. Using phylogenetic analysis, we identified homologs of FLC in species representing the three major eudicot lineages. FLC homologs have not previously been documented outside the plant family Brassicaceae. We show that the sugar beet FLC homolog BvFL1 functions as a repressor of flowering in transgenic Arabidopsis and is downregulated in response to cold in sugar beet. Cold-induced downregulation of an FLC-like floral repressor may be a central feature of the vernalization response in at least half of eudicot species.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, National Center for Genetic Resources Preservation, Fort Collins, Colorado 80521, USA.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Reeves
authors.forename: Yuehui
authors.initials: Y
authors.lastname: He
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Schmitz
authors.forename: Richard M
authors.initials: RM
authors.lastname: Amasino
authors.forename: Lee W
authors.initials: LW
authors.lastname: Panella
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Richards
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D027461:Beta vulgaris / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D003080:Cold Temperature; D015536:Down-Regulation / Q000235:genetics; D019143:Evolution, Molecular; D035264:Flowers / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000502:physiology; D030821:Plants, Genetically Modified; D012097:Repressor Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins; D012097:Repressor Proteins