title: Controlled turnover of CONSTANS protein by the HOS1 E3 ligase regulates floral transition at low temperatures.
abstract: The timing of flowering is coordinately regulated by complex gene regulatory networks that integrate developmental and environmental cues. Light and temperature are major environmental determinants in flowering time control. Temperature signals include two major categories: ambient temperature signals and cold nonfreezing temperature signals. Notably, the effects of cold temperatures on flowering timing are profoundly differentiated, depending on the duration of cold exposure. Whereas long-term exposure to cold temperatures, designated vernalization, promotes flowering, short-term cold exposure delays flowering. Genes constituting the vernalization pathway and underlying molecular mechanisms have been extensively studied. However, how cold stress signals delay flowering is largely unknown. We have recently reported that the HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 1 (HOS1)-CONSTANS (CO) module is at least partly responsible for the daily sensing of cold stress signals in flowering time control. Intermittent cold stress triggers the degradation of CO, a central activator of photoperiodic flowering, via a ubiquitination pathway that involves the HOS1 E3 ubiquitin ligase, leading to suppression of FLOWERING LOCUS T (FT) gene and delayed flowering. It is proposed that CO serves as a molecular knot that integrates photoperiod and temperature signals into the flowering pathways, fine-tuning photoperiodic flowering under short-term temperature fluctuations.
authors: Department of Chemistry; Chonbuk National University; Jeonju, Korea.
authors: Pil
authors: P
authors: Joon Seo
authors: Jae-Hoon
authors: JH
authors: Jung
authors: Mi-Jeong
authors: MJ
authors: Park
authors: Kyounghee
authors: K
authors: Lee
authors: Chung-Mo
authors: CM
authors: Park
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D017440:Photoperiod; D063245:Plant Development / Q000235:genetics*; D015398:Signal Transduction; D013312:Stress, Physiological / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; C418902:At5g10140 protein, Arabidopsis; C418905:FT protein, Arabidopsis; C425768:HOS1 protein, Arabidopsis; D047908:Intracellular Signaling Peptides and Proteins; D026161:MADS Domain Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases
keywords: Arabidopsis; CONSTANS; HOS1; flowering; intermittent cold stress; ubiquitination