title: NADH-dependent glutamate synthase participated in ammonium assimilation in Arabidopsis root.
abstract: Higher plants have 2 GOGAT species, Fd-GOGAT and NADH-GOGAT. While Fd-GOGAT mainly assimilates ammonium in leaves, which is derived from photorespiration, the function of NADH-GOGAT, which is highly expressed in roots, (1) needs to be elucidated. The aim of this study was to clarify the role of NADH-GOGAT in Arabidopsis roots. The supply of ammonium to the roots caused an accumulation of NADH-GOGAT, while Fd-GOGAT 1 and Fd-GOGAT 2 showed no response. A promoter-GUS fusion analysis and immunohistochemistry showed that NADH-GOGAT was located in non-green tissues like vascular bundles, shoot apical meristem, pollen, stigma, and roots. The localization of NADH-GOGAT and Fd-GOGAT was not overlapped. NADH-GOGAT T-DNA insertion lines showed a reduction of glutamate and biomass under normal CO2 conditions. These data emphasizes the importance of NADH-GOGAT in the ammonium assimilation of Arabidopsis roots.
authors.affiliation: a Graduate School of Agricultural Science; Tohoku University; Sendai, Japan.
authors.forename: Soichi
authors.initials: S
authors.lastname: Kojima
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Konishi
authors.forename: Marcel Pascal
authors.initials: MP
authors.lastname: Beier
authors.forename: Keiki
authors.initials: K
authors.lastname: Ishiyama
authors.forename: Ikumi
authors.initials: I
authors.lastname: Maru
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamaya
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D064751:Ammonium Compounds / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D018533:Biomass; D004269:DNA, Bacterial; D050790:Glutamate Synthase (NADH) / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D008027:Light; D009584:Nitrogen / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic
chemical_list: D064751:Ammonium Compounds; D004269:DNA, Bacterial; C036483:T-DNA; D018698:Glutamic Acid; D000594:Amino Acid Oxidoreductases; D050790:Glutamate Synthase (NADH); C042233:glutamate synthase (ferredoxin); D009584:Nitrogen
keywords: Arabidopsis; CO2; NADH-GOGAT; amino acids; ammonium; assimilation; glutamate; root