The cytosolic glutamine synthetase GLN1;2 plays a role in the control of plant growth and ammonium homeostasis in Arabidopsis rosettes when nitrate supply is not limiting

Autor: Thomas Lemaitre, Jérémy Lothier, Laure Gaufichon, Michèle Reisdorf-Cren, Rodnay Sormani, Marianne Azzopardi, Fabien Chardon, Halima Morin, Jean-Christophe Avice, Céline Masclaux-Daubresse
Přispěvatelé: Sciences Agronomiques Appliquées à l'Horticulture (SAGAH), Université d'Angers (UA)-Institut National de la Recherche Agronomique (INRA)-Institut National d'Horticulture, Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Ecophysiologie Végétale, Agronomie et Nutritions (EVA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Recherche Agronomique (INRA), Institut National d'Horticulture-Institut National de la Recherche Agronomique (INRA)-Université d'Angers (UA), University of Versailles Saint-Quentin en Yvelines, Sciences Agronomiques Appliquées à l'Horticulture ( SAGAH ), Université d'Angers ( UA ) -Institut National de la Recherche Agronomique ( INRA ) -Institut National d'Horticulture, Institut Jean-Pierre Bourgin ( IJPB ), Institut National de la Recherche Agronomique ( INRA ) -AgroParisTech, Ecophysiologie Végétale, Agronomie et Nutritions ( EVA ), Institut National de la Recherche Agronomique ( INRA ) -Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ) -Normandie Université ( NU )
Jazyk: angličtina
Rok vydání: 2011
Předmět:
0106 biological sciences
[ SDV.BV.BOT ] Life Sciences [q-bio]/Vegetal Biology/Botanics
Arabidopsis thaliana
Nitrogen
Physiology
Nitrogen assimilation
Arabidopsis
HORTICULTURE
biologie des plantes
Plant Science
Root hair
Biology
01 natural sciences
Gene Knockout Techniques
03 medical and health sciences
chemistry.chemical_compound
adaptation des plantes à leur environnement
Nitrate
nitrogen remobilization
Glutamate-Ammonia Ligase
Glutamine synthetase
Botany
Homeostasis
companion cells
Ammonium
Promoter Regions
Genetic
Nitrogen cycle
030304 developmental biology
0303 health sciences
Nitrates
Arabidopsis Proteins
glutamine synthetase
nitrogen assimilation
[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics
Plant Leaves
Quaternary Ammonium Compounds
Glutamine
chemistry
Biochemistry
Phloem
010606 plant biology & botany
Zdroj: Journal of Experimental Botany
Journal of Experimental Botany, Oxford University Press (OUP), 2011, 62 (4), pp.1375-1390. ⟨10.1093/jxb/erq299⟩
Journal of Experimental Botany, Oxford University Press (OUP), 2011, 62 (4), pp.1375-1390. 〈10.1093/jxb/erq299〉
ISSN: 0022-0957
1460-2431
DOI: 10.1093/jxb/erq299⟩
Popis: Glutamine synthetase (EC 6.3.1.2) is a key enzyme of ammonium assimilation and recycling in plants where it catalyses the synthesis of glutamine from ammonium and glutamate. In Arabidopsis, five GLN1 genes encode GS1 isoforms. GLN1;2 is the most highly expressed in leaves and is over-expressed in roots by ammonium supply and in rosettes by ample nitrate supply compared with limiting nitrate supply. It is shown here that the GLN1;2 promoter is mainly active in the minor veins of leaves and flowers and, to a lower extent, in the parenchyma of mature leaves. Cytoimmunochemistry reveals that the GLN1;2 protein is present in the companion cells. The role of GLN1;2 was determined by examining the physiology of gln1;2 knockout mutants. Mutants displayed lower glutamine synthetase activity, higher ammonium concentration, and reduced rosette biomass compared with the wild type (WT) under ample nitrate supply only. No difference between mutant and WT can be detected under limiting nitrate conditions. Despite total amino acid concentration was increased in the old leaves of mutants at high nitrate, no significant difference in nitrogen remobilization can be detected using (15)N tracing. Growing plants in vitro with ammonium or nitrate as the sole nitrogen source allowed us to confirm that GLN1;2 is induced by ammonium in roots and to observe that gln1;2 mutants displayed, under such conditions, longer root hair and smaller rosette phenotypes in ammonium. Altogether the results suggest that GLN1;2 is essential for nitrogen assimilation under ample nitrate supply and for ammonium detoxification.
Databáze: OpenAIRE
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