title: High nitrogen insensitive 9 (HNI9)-mediated systemic repression of root NO3- uptake is associated with changes in histone methylation.
abstract: In plants, root nitrate uptake systems are under systemic feedback repression by the N satiety of the whole organism, thus adjusting the N acquisition capacity to the N demand for growth; however, the underlying molecular mechanisms are largely unknown. We previously isolated the Arabidopsis high nitrogen-insensitive 9-1 (hni9-1) mutant, impaired in the systemic feedback repression of the root nitrate transporter NRT2.1 by high N supply. Here, we show that HNI9 encodes Arabidopsis INTERACT WITH SPT6 (AtIWS1), an evolutionary conserved component of the RNA polymerase II complex. HNI9/AtIWS1 acts in roots to repress NRT2.1 transcription in response to high N supply. At a genomic level, HNI9/AtIWS1 is shown to play a broader role in N signaling by regulating several hundred N-responsive genes in roots. Repression of NRT2.1 transcription by high N supply is associated with an HNI9/AtIWS1-dependent increase in histone H3 lysine 27 trimethylation at the NRT2.1 locus. Our findings highlight the hypothesis that posttranslational chromatin modifications control nutrient acquisition in plants.
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Unité Mixte de Recherche 5004, Institut National de la Recherche Agronomique-Centre National de la Recherche Scientifique-Sup Agro-UM2, Institut de Biologie Intégrative des Plantes, F-34060 Montpellier, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Widiez
authors.forename: El Sayed
authors.initials: el S
authors.lastname: El Kafafi
authors.forename: Thomas
authors.initials: T
authors.lastname: Girin
authors.forename: Alexandre
authors.initials: A
authors.lastname: Berr
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ruffel
authors.forename: Gabriel
authors.initials: G
authors.lastname: Krouk
authors.forename: Alice
authors.initials: A
authors.lastname: Vayssières
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Shen
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Coruzzi
authors.forename: Alain
authors.initials: A
authors.lastname: Gojon
authors.forename: Marc
authors.initials: M
authors.lastname: Lepetit
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D006657:Histones / Q000378:metabolism*; D008745:Methylation / Q000187:drug effects; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012319:RNA Polymerase II / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; D002843:Chromatin; D006657:Histones; D009566:Nitrates; D009584:Nitrogen; D012319:RNA Polymerase II; D014157:Transcription Factors; C477335:NRT2.1 protein, Arabidopsis; C548338:IWS1 protein, Arabidopsis