Localization of NAD-isocitrate dehydrogenase and glutamate dehydrogenase in rice roots: candidates for providing carbon skeletons to NADH-glutamate synthase.
Plant Cell Physiol
; 46(10): 1724-34, 2005 Oct.
Article
em En
| MEDLINE
| ID: mdl-16120687
ABSTRACT
In rice roots, transient and cell-type-specific accumulation of both mRNA and protein for NADH-dependent glutamate synthase (NADH-GOGAT) occurs after the supply of NH(4) (+) ions. In order to better understand the origin of 2-oxoglutarate for this reaction, we focused on mitochondrial NAD-dependent isocitrate dehydrogenase (IDH) and glutamate dehydrogenase (GDH) in rice roots. Six rice cDNAs encoding a single catalytic (OsIDHa) and two regulatory (OsIDHc;1, OsIDHc;2) IDH subunits and three GDH proteins (OsGDH1-3) were isolated. These genes, except OsGDH3, were expressed in the roots. Real-time PCR analysis showed that OsIDHa and OsIDHc;1 transcripts, but not OsGDH1 and OsGDH2 transcripts, accumulated in a similar manner to NADH-GOGAT mRNA along the crown roots after the supply of different forms of inorganic nitrogen. Furthermore, immunolocalization studies revealed the NH(4) (+) induction of IDHa protein in two cell layers of the root surface, i.e. epidermis and exodermis, where NADH-GOGAT also accumulated. The possible relationship between NADH-GOGAT, IDH and GDH is discussed.
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Base de dados:
MEDLINE
Assunto principal:
Oryza
/
Carbono
/
Raízes de Plantas
/
Glutamato Sintase (NADH)
/
Glutamato Desidrogenase
/
Isocitrato Desidrogenase
Idioma:
En
Revista:
Plant Cell Physiol
Assunto da revista:
BOTANICA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Japão