title: Fackel interacts with gibberellic acid signaling and vernalization to mediate flowering in Arabidopsis.
abstract: Fackel (FK) is involved in the flowering of Arabidopsis mainly via the gibberellin pathway and vernalization pathway. This new function of FK is partially dependent on the FLOWERING LOCUS C ( FLC ). A common transitional process from vegetative stage to reproductive stage exists in higher plants during their life cycle. The initiation of flower bud differentiation, which plays a key role in the reproductive phase, is affected by both external environmental and internal regulatory factors. In this study, we showed that the Arabidopsis weak mutant allele fk-J3158, impaired in the FACKEL (FK) gene, which encodes a C-14 reductase involved in sterol biosynthesis, had a long life cycle and delayed flowering time in different photoperiods. In addition, FK overexpression lines displayed an earlier flowering phenotype than that of the wild type. These processes might be independent of the downstream brassinosteroid (BR) pathway and the autonomous pathway. However, the fk-J3158 plants were more sensitive than wild type in reducing the bolting days and total leaf number under gibberellic acid (GA) treatment. Further studies suggested that FK mutation led to an absence of endogenous GAs in fk-J3158 and FK gene expression was also affected under GA and paclobutrazol (PAC) treatment. Moreover, the delayed flowering time of fk-J3158 could be rescued by a 3-week vernalization treatment, and the expression of FLOWERING LOCUS C (FLC) was accordingly down-regulated in fk-J3158. We also demonstrated that flowering time of fk-J3158 flc double mutant was significantly earlier than that of fk-J3158 under the long-day (LD) conditions. All these results indicated that FK may affect the flowering in Arabidopsis mainly via GA pathway and vernalization pathway. And these effects are partially dependent on the FLOWERING LOCUS C (FLC).
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
authors.forename: Bingyao
authors.initials: B
authors.lastname: Huang
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.|Department of Biological Science, Graduate School of Sciences, Osaka University, Toyonaka, Osaka, 560-0043, Japan.
authors.forename: Pingping
authors.initials: P
authors.lastname: Qian
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
authors.forename: Na
authors.initials: N
authors.lastname: Gao
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China. housw@lzu.edu.cn.
authors.forename: Suiwen
authors.initials: S
authors.lastname: Hou
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000201:enzymology / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D017930:Genes, Reporter; D005875:Gibberellins / Q000378:metabolism*; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D017440:Photoperiod; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000201:enzymology / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; C418902:At5g10140 protein, Arabidopsis; D005875:Gibberellins; D026161:MADS Domain Proteins; D010937:Plant Growth Regulators; C007842:gibberellic acid; D010088:Oxidoreductases; C022672:delta(14)-sterol reductase
keywords: Brassinosteroid; FLOWERING LOCUS C; Fackel; Flowering; Gibberellic acid; Sterol; Vernalization