Plant Molecular Biology

, Volume 67, Issue 1, pp 89–105

Gene expression, cellular localisation and function of glutamine synthetase isozymes in wheat (Triticum aestivum L.)

  • Stéphanie M. Bernard
  • Anders Laurell Blom Møller
  • Giuseppe Dionisio
  • Thomas Kichey
  • Thomas P. Jahn
  • Frederic Dubois
  • Marcela Baudo
  • Marta S. Lopes
  • Thérèse Tercé-Laforgue
  • Christine H. Foyer
  • Martin A. J. Parry
  • Brian G. Forde
  • Jose Luis Araus
  • Bertrand Hirel
  • Jan K. Schjoerring
  • Dimah Z. Habash
Article

DOI: 10.1007/s11103-008-9303-y

Cite this article as:
Bernard, S.M., Møller, A.L.B., Dionisio, G. et al. Plant Mol Biol (2008) 67: 89. doi:10.1007/s11103-008-9303-y

Abstract

We present the first cloning and study of glutamine synthetase (GS) genes in wheat (Triticum aestivum L.). Based on sequence analysis, phylogenetic studies and mapping data, ten GS sequences were classified into four sub-families: GS2 (a, b and c), GS1 (a, b and c), GSr (1 and 2) and GSe (1 and 2). Phylogenetic analysis showed that the wheat GS sub-families together with the GS genes from other monocotyledonous species form four distinct clades. Immunolocalisation studies in leaves, stems and rachis in plants at flowering showed GS protein to be present in parenchyma, phloem companion and perifascicular sheath cells. In situ localisation confirmed that GS1 transcripts were present in the perifascicular sheath cells whilst those for GSr were confined to the vascular cells. Studies of the expression and protein profiles showed that all GS sub-families were differentially expressed in the leaves, peduncle, glumes and roots. Expression of GS genes in leaves was developmentally regulated, with both GS2 and GS1 assimilating or recycling ammonia in leaves during the period of grain development and filling. During leaf senescence the cytosolic isozymes, GS1 and GSr, were the predominant forms, suggesting major roles in assimilating ammonia during the critical phases of remobilisation of nitrogen to the grain. A preliminary analysis of three different wheat genotypes showed that the ratio of leaf GS2 protein to GS1 protein was variable. Use of this genetic variation should inform future efforts to modulate this enzyme for pre-breeding efforts to improve nitrogen use in wheat.

Keywords

Glutamine synthetaseWheatSenescenceNitrogenGene expressionIn situ hybridisationImmunolocalisation

Abbreviations

GS

Glutamine synthetase

QTL

Quantitative trait loci

DH

Doubled haploid

qRT-PCR

Real-time reverse transcription polymerase chain reaction

RACE

Rapid amplification of cDNA ends

Supplementary material

11103_2008_9303_MOESM1_ESM.doc (76 kb)
Table S1Sequences of primers used in RACE I: primers for cloning experiments (DOC 76 kb)
11103_2008_9303_MOESM2_ESM.doc (33 kb)
Table S2Sequences of primers and probes for TaqMan assays. Nucleotides in bold and underlined were Locked Nucleic Acid (LNA) bases. Primers were designed not to discriminate between possible homeoalleles (DOC 33 kb)
11103_2008_9303_MOESM3_ESM.tif (3.9 mb)
Fig. S1Transmission electron microscopic immunolocalisation using pre immune serum for GS in leaf parenchyma cell (A). In situ localisation of sense probes for GS1 in leaf (B) and stem (C) tissue. M, mitochondria; pa, parenchyma; pl, plastid; vb, vascular bundle. Bars: 0.5 μm (A) and 100 μm (B, C) (TIF 3974 kb)

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Stéphanie M. Bernard
    • 1
    • 2
  • Anders Laurell Blom Møller
    • 3
  • Giuseppe Dionisio
    • 3
  • Thomas Kichey
    • 4
  • Thomas P. Jahn
    • 3
  • Frederic Dubois
    • 4
  • Marcela Baudo
    • 1
  • Marta S. Lopes
    • 5
  • Thérèse Tercé-Laforgue
    • 6
  • Christine H. Foyer
    • 1
  • Martin A. J. Parry
    • 1
  • Brian G. Forde
    • 7
  • Jose Luis Araus
    • 5
  • Bertrand Hirel
    • 6
  • Jan K. Schjoerring
    • 3
  • Dimah Z. Habash
    • 1
  1. 1.Plant Science Department, Centre for Crop Genetic ImprovementRothamsted ResearchHarpendenUK
  2. 2.Ecology DepartmentLawrence Berkeley National LaboratoryBerkeleyUSA
  3. 3.Plant and Soil Science Laboratory, Department of Agricultural Science, Faculty of Life SciencesThe University of CopenhagenFrederiksberg C, CopenhagenDenmark
  4. 4.Unité de Biologie des Plantes et Contrôle des Insectes RavageursUniversité de Picardie Jules VerneAmiens CedexFrance
  5. 5.Unitat de Fisiologia Vegetal, Departament de Biologia Vegetal, Facultat de BiologiaUniversitat de BarcelonaBarcelonaSpain
  6. 6.Laboratoire de Nutrition Azotée des PlantesINRAVersaillesFrance
  7. 7.Lancaster Environment Centre, Department of Biological SciencesLancaster UniversityLancasterUK