Possible role of early flowering 3 (ELF3) in clock-dependent floral regulation by short vegetative phase (SVP) in Arabidopsis thaliana.
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.
Yoshida
Riichiro
R
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Fekih
Rym
R
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Fujiwara
Sumire
S
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Oda
Atsushi
A
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Miyata
Kana
K
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Tomozoe
Yusuke
Y
ALOKA Co., Ltd, Mure 6-22-1, Mitaka, Tokyo 181-8622, Japan.
Nakagawa
Mayu
M
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Niinuma
Kanae
K
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Hayashi
Kounosuke
K
ALOKA Co., Ltd, Mure 6-22-1, Mitaka, Tokyo 181-8622, Japan.
Ezura
Hiroshi
H
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
Coupland
George
G
Max Planck Institute for Plant Breeding, Carl von Linne Weg 10, D-50829 Cologne, Germany.
Mizoguchi
Tsuyoshi
T
Gene Research Center, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan.
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
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