title: A root chicory MADS box sequence and the Arabidopsis flowering repressor FLC share common features that suggest conserved function in vernalization and de-vernalization responses.
abstract: Root chicory (Cichorium intybus var. sativum) is a biennial crop, but is harvested to obtain root inulin at the end of the first growing season before flowering. However, cold temperatures may vernalize seeds or plantlets, leading to incidental early flowering, and hence understanding the molecular basis of vernalization is important. A MADS box sequence was isolated by RT-PCR and named FLC-LIKE1 (CiFL1) because of its phylogenetic positioning within the same clade as the floral repressor Arabidopsis FLOWERING LOCUS C (AtFLC). Moreover, over-expression of CiFL1 in Arabidopsis caused late flowering and prevented up-regulation of the AtFLC target FLOWERING LOCUS T by photoperiod, suggesting functional conservation between root chicory and Arabidopsis. Like AtFLC in Arabidopsis, CiFL1 was repressed during vernalization of seeds or plantlets of chicory, but repression of CiFL1 was unstable when the post-vernalization temperature was favorable to flowering and when it de-vernalized the plants. This instability of CiFL1 repression may be linked to the bienniality of root chicory compared with the annual lifecycle of Arabidopsis. However, re-activation of AtFLC was also observed in Arabidopsis when a high temperature treatment was used straight after seed vernalization, eliminating the promotive effect of cold on flowering. Cold-induced down-regulation of a MADS box floral repressor and its re-activation by high temperature thus appear to be conserved features of the vernalization and de-vernalization responses in distant species.
authors.affiliation: Laboratoire de Physiologie Végétale, PhytoSYSTEMS, Université de Liège, Sart Tilman B22, Boulevard du Rectorat 27, Liège B-4000, Belgium. cperilleux@ulg.ac.be
authors.forename: Claire
authors.initials: C
authors.lastname: Périlleux
authors.forename: Alexandra
authors.initials: A
authors.lastname: Pieltain
authors.forename: Guillaume
authors.initials: G
authors.lastname: Jacquemin
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bouché
authors.forename: Nathalie
authors.initials: N
authors.lastname: Detry
authors.forename: Maria
authors.initials: M
authors.lastname: D'Aloia
authors.forename: Laura
authors.initials: L
authors.lastname: Thiry
authors.forename: Pierre
authors.initials: P
authors.lastname: Aljochim
authors.forename: Martin
authors.initials: M
authors.lastname: Delansnay
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Mathieu
authors.forename: Stanley
authors.initials: S
authors.lastname: Lutts
authors.forename: Pierre
authors.initials: P
authors.lastname: Tocquin
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018651:Cichorium intybus / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D003080:Cold Temperature; D035264:Flowers / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; C418902:At5g10140 protein, Arabidopsis; D026161:MADS Domain Proteins; D010940:Plant Proteins; D012097:Repressor Proteins
keywords: Arabidopsis thaliana; Cichorium intybus; FLC; bienniality; de-vernalization; flowering; root chicory; vernalization