title: Negative regulatory roles of DE-ETIOLATED1 in flowering time in Arabidopsis.
abstract: Arabidopsis flowers early under long days (LD) and late under short days (SD). The repressor of photomorphogenesis DE-ETIOLATED1 (DET1) delays flowering; det1-1 mutants flower early, especially under SD, but the molecular mechanism of DET1 regulation remains unknown. Here we examine the regulatory function of DET1 in repression of flowering. Under SD, the det1-1 mutation causes daytime expression of FKF1 and CO; however, their altered expression has only a small effect on early flowering in det1-1 mutants. Notably, DET1 interacts with GI and binding of GI to the FT promoter increases in det1-1 mutants, suggesting that DET1 mainly restricts GI function, directly promoting FT expression independent of CO expression. Moreover, DET1 interacts with MSI4/FVE, which epigenetically inhibits FLC expression, indicating that the lack of FLC expression in det1-1 mutants likely involves altered histone modifications at the FLC locus. These data demonstrate that DET1 acts in both photoperiod and autonomous pathways to inhibit expression of FT and SOC1. Consistent with this, the early flowering of det1-1 mutants disappears completely in the ft-1 soc1-2 double mutant background. Thus, we propose that DET1 is a strong repressor of flowering and has a pivotal role in maintaining photoperiod sensitivity in the regulation of flowering time.
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Min-Young
authors.initials: MY
authors.lastname: Kang
authors.affiliation: Department of Plant Life and Environmental Science, Hankyong National University, Ansung 456-749, Korea.
authors.forename: Soo-Cheul
authors.initials: SC
authors.lastname: Yoo
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Hye-Young
authors.initials: HY
authors.lastname: Kwon
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Byoung-Doo
authors.initials: BD
authors.lastname: Lee
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Korea.
authors.forename: Jung-Nam
authors.initials: JN
authors.lastname: Cho
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Korea.
authors.forename: Yoo-Sun
authors.initials: YS
authors.lastname: Noh
authors.affiliation: 1] Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea [2] Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 232-916, Korea.
authors.forename: Nam-Chon
authors.initials: NC
authors.lastname: Paek
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D006657:Histones / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C419046:AGL20 protein, Arabidopsis; D029681:Arabidopsis Proteins; C088435:DET1 protein, Arabidopsis; C410504:FKF1 protein, Arabidopsis; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; D026161:MADS Domain Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins