Characterization of a NADH-dependent glutamate dehydrogenase mutant of [i]Arabidopsis[/i] demonstrates the key role of this enzyme in root carbon and nitrogen metabolism
Fontaine, Jean-Xavier, J.-X. | Tercé-Laforgue, Therese | Armengaud, Patrick | Clément, Gilles | Renou, Jean-Pierre | Pelletier, Sandra | Catterou, Manuella | Azzopardi, Marianne | Gibon, Yves | Lea, Peter J. | Hirel, Bertrand | Dubois, Frédéric | Biologie des Plantes et Innovation - UR UPJV 3900 (BIOPI) ; Université de Picardie Jules Verne (UPJV) | Institut Jean-Pierre Bourgin (IJPB) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Unité de recherche en génomique végétale (URGV) ; Institut National de la Recherche Agronomique (INRA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS) | Ecologie et Dynamique des Systèmes Anthropisés - UMR CNRS 7058 UPJV (EDYSAN) ; Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS) | Biologie du fruit et pathologie (BFP) ; Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1 (UB) | Rothamsted Research ; Biotechnology and Biological Sciences Research Council (BBSRC)
L'article original est publié par The American Society of Plant Biologists
Показать больше [+] Меньше [-]Английский. The role of NADH-dependent glutamate dehydrogenase (GDH) was investigated by studying the physiological impact of a complete lack of enzyme activity in an Arabidopsis thaliana plant deficient in three genes encoding the enzyme. This study was conducted following the discovery that a third GDH gene is expressed in the mitochondria of the root companion cells, where all three active GDH enzyme proteins were shown to be present. A gdh1-2-3 triple mutant was constructed and exhibited major differences from the wild type in gene transcription and metabolite concentrations, and these differences appeared to originate in the roots. By placing the gdh triple mutant under continuous darkness for several days and comparing it to the wild type, the evidence strongly suggested that the main physiological function of NADH-GDH is to provide 2-oxoglutarate for the tricarboxylic acid cycle. The differences in key metabolites of the tricarboxylic acid cycle in the triple mutant versus the wild type indicated that, through metabolic processes operating mainly in roots, there was a strong impact on amino acid accumulation, in particular alanine, gamma-aminobutyrate, and aspartate in both roots and leaves. These results are discussed in relation to the possible signaling and physiological functions of the enzyme at the interface of carbon and nitrogen metabolism.
Показать больше [+] Меньше [-]Библиографическая информация
Эту запись предоставил Institut national de la recherche agronomique