Nom du corpus

Corpus Systématique Végétale

Titre du document

Compartmentation and flux characteristics of ammonium in spruce

Lien vers le document
Éditeur
Springer (journals)
Langue(s) du document
Anglais
Type de document
Research-article
Mots-clés d'auteur
  • Ammonium
  • Compartmental analysis
  • Nitrogen-13
  • Picea
  • [NH4+]cyt : cytoplasmic NH 4 + concentration
  • [NH4+]free space : NH 4 + concentration in the Donnan freespace
  • [NH4+]o : concentration of NH 4 + in the external solution
  • φ : NH 4 + flux (for subscripts, see Materials and methods)
Nom du fichier dans la ressource
Syst_veg6_v2_019147
Auteur(s)
  • Herbert J. Kronzucker 1
  • M. Yaeesh Siddiqi 1
  • Anthony D. M. Glass 1
Affiliation(s)
  • 1) Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada
Résumé

Using 13NH 4 + as a tracer, compartmental analyses for NH 4 + were performed in non-mycorrhizal roots of intact Picea glauca (Moench) Voss. seedlings at four different concentration regimes of external NH 4 + ([NH 4 + ]o), i.e. 0, 10, 100, and 1500 μM. Three kinetically distinct compartments were identified, with half-lives of exchange of approximately 2 s, 30 s, and 14 min, assumed to represent surface adsorption, Donnan free space, and cytoplasm, respectively. No significant differences were found in half-lives of exchange with changes in [NH 4 + ]o. Influx was calculated to be 0.96 μmol·g−1·h−1 in N-deprived plants (measured at 10 μM [NH 4 + ]o), while under steady-state conditions it was 0.21 μmol·g−1h−1 at 10 μM [NH 4 + ]o, 1.96 μmol·g−1h·−1 at 100 μM [NH 4 + ]o, and 6.45 μmol·g−1·h−1 at 1.5 mM [NH 4 + ]o. Efflux measured over the same range constituted approximately 9% of influx in N-deprived plants, 10% at 10 μM, 28% at 100 μM, and 35% at 1.5 mM [NH 4 + ]o. Cytoplasmic [NH 4 + ] was estimated at 6 m M in N-deprived plants, 2 mM at 10 μM [NH 4 + ]o, 14 mM at 100 μM, and 33 mM at 1.5 mM. Free-space [NH 4 + ] was 84 μM, 50 μM, 700 μM, and 8 mM, respectively. In comparison with previously published data on fluxes and compartmentation of NO 3 − in white-spruce seedlings, results of this study identify a pronounced physiological preference of this species for NH 4 + over NO 3 − as an inorganic N source in terms of uptake and intracellular accumulation. The significant ecological importance of this N-source preference is discussed.

Catégories Science-Metrix
  • 1 - natural sciences
  • 2 - biology
  • 3 - plant biology & botany
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Plant Science
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Genetics
Catégories WoS
  • 1 - science ; 2 - plant sciences
Identifiant ISTEX
EC5FFAE4009E085CF2A57C5344DEC07972A0AB01
Revue

Planta

Année de publication
1995
Présence de XML structuré
Non
Score qualité du texte
10
Version PDF
1.3
Type de publication
Journal
ark:/67375/1BB-0NDMRD9X-L
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