title: The mitogen-activated protein kinase phosphatase PHS1 regulates flowering in Arabidopsis thaliana.
abstract: Arabidopsis PHS1, initially known as an actor of cytoskeleton organization, is a positive regulator of flowering in the photoperiodic and autonomous pathways by modulating both CO and FLC mRNA levels. Protein phosphorylation and dephosphorylation is a major type of post-translational modification, controlling many biological processes. In Arabidopsis thaliana, five genes encoding MAPK phosphatases (MKP)-like proteins have been identified. Among them, PROPYZAMIDE HYPERSENSITIVE 1 (PHS1) encoding a dual-specificity protein tyrosine phosphatase (DsPTP) has been shown to be involved in microtubule organization, germination and ABA-regulated stomatal opening. Here, we demonstrate that PHS1 also regulates flowering under long-day and short-day conditions. Using physiological, genetic and molecular approaches, we have shown that the late flowering phenotype of the knock-out phs1-5 mutant is linked to a higher expression of FLOWERING LOCUS C (FLC). In contrast, a decline of both CONSTANS (CO) and FLOWERING LOCUS T (FT) expression is observed in the knock-out phs1-5 mutant, especially at the end of the light period under long-day conditions when the induction of flowering occurs. We show that this partial loss of sensitivity to photoperiodic induction is independent of FLC. Our results thus indicate that PHS1 plays a dual role in flowering, in the photoperiodic and autonomous pathways, by modulating both CO and FLC mRNA levels. Our work reveals a novel actor in the complex network of the flowering regulation.
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Sorbonne Universités, UPMC Univ Paris 06, URF5, 75005, Paris, France.|Plant Biological Sciences Graduate Program, Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, Saint Paul, MN, 55108, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Sorbonne Universités, UPMC Univ Paris 06, URF5, 75005, Paris, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Guittard-Crilat
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Sorbonne Universités, UPMC Univ Paris 06, URF5, 75005, Paris, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Maldiney
authors.affiliation: Biologie du Développement, Sorbonne Universités, UPMC Univ. Paris 06, UMR 7622, 75005, Paris, France.|Biologie du Développement, CNRS, UMR 7622, 75005, Paris, France.
authors.forename: Yvette
authors.initials: Y
authors.lastname: Habricot
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Sorbonne Universités, UPMC Univ Paris 06, URF5, 75005, Paris, France.
authors.forename: Emile
authors.initials: E
authors.lastname: Miginiac
authors.affiliation: Computational and Quantitative Biology, Sorbonne Universités, UPMC Univ. Paris 06, UMR 7238, 75005, Paris, France. jean-pierre.bouly@upmc.fr.|Computational and Quantitative Biology, CNRS-UPMC UMR 7238, 15, rue de l'Ecole de Médecine, 75006, Paris, France. jean-pierre.bouly@upmc.fr.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bouly
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Sorbonne Universités, UPMC Univ Paris 06, URF5, 75005, Paris, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Lebreton
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D017440:Photoperiod; D030821:Plants, Genetically Modified; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; C418902:At5g10140 protein, Arabidopsis; C418905:FT protein, Arabidopsis; D026161:MADS Domain Proteins; D014157:Transcription Factors; C514675:PHS1 protein, Arabidopsis; D017027:Protein Tyrosine Phosphatases
keywords: Arabidopsis; CONSTANS; FLOWERING LOCUS C (FLC); FLOWERING LOCUS T (FT); Flowering; Phosphatase