title: Possible role of early flowering 3 (ELF3) in clock-dependent floral regulation by short vegetative phase (SVP) in Arabidopsis thaliana.
abstract: Circadian clock proteins play key roles in adaptations of plants to diurnal environmental conditions. The photoperiodic flowering response is one of the mechanisms of adaptation to seasonal changes in the lengths of day and night. Double mutations in two clock genes, late elongated hypocotyl (LHY) and circadian clock associated 1 (CCA1), accelerated flowering under short days (SDs) but delayed flowering under continuous light (LL) in Arabidopsis thaliana. The mechanism underlying the late flowering of lhy;cca1 mutants under LL was investigated here. Late flowering of plants with overexpression of short vegetative phase (SVP) was much more pronounced under SDs and enhanced by constans 2 (co-2) under long days (LDs), suggesting that SVP and CO act independently in the photoperiodic flowering pathway. However, how SVP and flowering locus C (FLC) mediated the effects of LHY/CCA1 and thus influenced flowering time was not completely clear. A mutant line lhy;cca1 in the Landsberg erecta (Ler) background was established, ethyl methanesulfonate (EMS)-mutagenized and used to screen suppressors of late flowering of lhy;cca1 under LL. Mutations in the clock gene early flowering 3 (ELF3) were identified as suppressors. Overexpression and loss-of-function of ELF3 influenced SVP protein accumulation. Therefore, we propose that, as well as the classical GIGANTEA (GI)-CO pathway, LHY/CCA1 regulates a pathway negatively controlling flowering locus T (FT), possibly via ELF3-SVP/FLC.
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Riichiro
authors.initials: R
authors.lastname: Yoshida
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Rym
authors.initials: R
authors.lastname: Fekih
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Sumire
authors.initials: S
authors.lastname: Fujiwara
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Oda
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Miyata
authors.affiliation: ALOKA Co., Ltd, Mure 6-22-1, Mitaka, Tokyo 181-8622, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tomozoe
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Nakagawa
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Niinuma
authors.affiliation: ALOKA Co., Ltd, Mure 6-22-1, Mitaka, Tokyo 181-8622, Japan.
authors.forename: Kounosuke
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ezura
authors.affiliation: Max Planck Institute for Plant Breeding, Carl von Linne Weg 10, D-50829 Cologne, Germany.
authors.forename: George
authors.initials: G
authors.lastname: Coupland
authors.affiliation: Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Mizoguchi
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D057906:Circadian Clocks / Q000235:genetics / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D016153:Genes, Suppressor; D008027:Light; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D013489:Suppression, Genetic / Q000528:radiation effects; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C114425:CCA1 protein, Arabidopsis; C432430:At2g25930 protein, Arabidopsis; C113192:LHY protein, Arabidopsis; C407549:SVP protein, Arabidopsis