title: Plasticity to soil water deficit in Arabidopsis thaliana: dissection of leaf development into underlying growth dynamic and cellular variables reveals invisible phenotypes.
abstract: Genetic variability in the plasticity of leaf area expansion in response to water deficit has been reported in Arabidopsis thaliana. Here, the objective was to identify the underlying dynamic and cellular processes involved in this variability. Twenty-five accessions were subjected to identical soil water deficit treatments. In all accessions, the plasticity of leaf production was low compared with that of individual leaf expansion. A subset of accessions was selected for further dissection of individual leaf expansion into its underlying variables: the rate and duration of leaf expansion and epidermal cell number and area. In all accessions, water deficit had opposite effects on the rate and duration of leaf expansion. The accumulation of these effects was reflected in changes in final leaf area. At the cellular level, moderate water deficits had opposite effects on cell number and cell size, but more severe ones reduced both variables. The importance of these opposing effects is highlighted by the behaviour of the accession An-1, for which the compensation between the decrease in leaf expansion rate and the increase in the duration of expansion is total. This dynamic plasticity in response to water deficit is not detectable when only final measurements are done.
authors.affiliation: Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux UMR 759, Institut de Biologie Intégrative des Plantes, Institut National de la Recherche Agronomique/Ecole Nationale Supérieure d'Agronomie, Place Viala, Montpellier, France.
authors.forename: Luis
authors.initials: L
authors.lastname: Aguirrezabal
authors.forename: Sandrine
authors.initials: S
authors.lastname: Bouchier-Combaud
authors.forename: Amandine
authors.initials: A
authors.lastname: Radziejwoski
authors.forename: Myriam
authors.initials: M
authors.lastname: Dauzat
authors.forename: Sarah Jane
authors.initials: SJ
authors.lastname: Cookson
authors.forename: Christine
authors.initials: C
authors.lastname: Granier
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000254:growth & development* / Q000502:physiology*; D002452:Cell Count; D048429:Cell Size; D010641:Phenotype; D018515:Plant Leaves / Q000166:cytology / Q000254:growth & development* / Q000502:physiology*; D012987:Soil; D014867:Water / Q000032:analysis / Q000378:metabolism*
chemical_list: D012987:Soil; D014867:Water