title: Acetylated 1,3-diaminopropane antagonizes abscisic acid-mediated stomatal closing in Arabidopsis.
abstract: Faced with declining soil-water potential, plants synthesize abscisic acid (ABA), which then triggers stomatal closure to conserve tissue moisture. Closed stomates, however, also create several physiological dilemmas. Among these, the large CO2 influx required for net photosynthesis will be disrupted. Depleting CO2 in the plant will in turn bias stomatal opening by suppressing ABA sensitivity, which then aggravates transpiration further. We have investigated the molecular basis of how C3 plants resolve this H2 O-CO2 conflicting priority created by stomatal closure. Here, we have identified in Arabidopsis thaliana an early drought-induced spermidine spermine-N(1) -acetyltransferase homolog, which can slow ABA-mediated stomatal closure. Evidence from genetic, biochemical and physiological analyses has revealed that this protein does so by acetylating the metabolite 1,3-diaminopropane (DAP), thereby turning on the latter's intrinsic activity. Acetylated DAP triggers plasma membrane electrical and ion transport properties in an opposite way to those by ABA. Thus in adapting to low soil-water availability, acetyl-DAP could refrain stomates from complete closure to sustain CO2 diffusion to photosynthetic tissues.
authors.affiliation: Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2355, Saclay Plant Sciences, Avenue de la Terrasse Bâtiment 23, 91198, Gif-sur-Yvette Cedex, France; Department of Biology, Pomona College, Claremont, CA, 91711, USA.
authors.forename: Fabien
authors.initials: F
authors.lastname: Jammes
authors.forename: Nathalie
authors.initials: N
authors.lastname: Leonhardt
authors.forename: Daniel
authors.initials: D
authors.lastname: Tran
authors.forename: Hadjira
authors.initials: H
authors.lastname: Bousserouel
authors.forename: Anne-Aliénor
authors.initials: AA
authors.lastname: Véry
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Renou
authors.forename: Alain
authors.initials: A
authors.lastname: Vavasseur
authors.forename: June M
authors.initials: JM
authors.lastname: Kwak
authors.forename: Hervé
authors.initials: H
authors.lastname: Sentenac
authors.forename: François
authors.initials: F
authors.lastname: Bouteau
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Leung
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D003959:Diamines / Q000378:metabolism*; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D054046:Plant Stomata / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003959:Diamines; D000040:Abscisic Acid; C009475:trimethylenediamine
keywords: 1,3-diaminopropane; Arabidopsis thaliana; abscisic acid; acetyltransferase; drought; guard cells; polyamines