title: Glutamate dehydrogenase isoenzyme 3 (GDH3) of Arabidopsis thaliana is regulated by a combined effect of nitrogen and cytokinin.
abstract: In higher plants, NAD(H)-glutamate dehydrogenase (GDH; EC 1.4.1.2) is an abundant enzyme that exists in different isoenzymic forms. In Arabidopsis thaliana, three genes (Gdh1, Gdh2 and Gdh3) encode three different GDH subunits (β, α and γ) that randomly associate to form a complex array of homo- and heterohexamers. The modification of the GDH isoenzyme pattern and its regulation was studied during the development of A. thaliana in the gdh1, gdh2 single mutants and the gdh1-2 double mutant, with particular emphasis on GDH3. Investigations showed that the GDH3 isoenzyme could not be detected in closely related Arabidopsis species. The induction and regulation of GDH3 activity in the leaves and roots was investigated following nitrogen deprivation in the presence or absence of sucrose or kinetin. These experiments indicate that GDH3 is likely to play an important role during senescence and nutrient remobilization.
authors.affiliation: Dipartimento di Bioscienze, Università di Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Marchi
authors.forename: Francesca
authors.initials: F
authors.lastname: Degola
authors.forename: Eugenia
authors.initials: E
authors.lastname: Polverini
authors.forename: Thérèse
authors.initials: T
authors.lastname: Tercé-Laforgue
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dubois
authors.forename: Bertrand
authors.initials: B
authors.lastname: Hirel
authors.forename: Francesco Maria
authors.initials: FM
authors.lastname: Restivo
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D050260:Carbohydrate Metabolism / Q000235:genetics*; D002244:Carbon / Q000378:metabolism*; D016922:Cellular Senescence; D003583:Cytokinins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005969:Glutamate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D007701:Kinetin / Q000378:metabolism; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D055503:Protein Multimerization; D021122:Protein Subunits; D013045:Species Specificity; D013395:Sucrose / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D007527:Isoenzymes; D021122:Protein Subunits; D013395:Sucrose; D002244:Carbon; D005969:Glutamate Dehydrogenase; D009584:Nitrogen; D007701:Kinetin
keywords: C; CK; Cytokinin; DAS; GDH; Glutamate dehydrogenase; Isoenzymes; N; NAD(H)-dependent glutamate dehydrogenase; Nitrogen starvation; Subunits; carbon; cytokinins; days after sowing; nitrogen