ISSN:
1432-2048
Keywords:
Cellular localization
;
NADH-glutamate synthase
;
Nitrogen metabolism
;
Oryza (glutamate synthase)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Tissue and cellular localization of NADH-dependent glutamate synthase (NADH-GOGAT, EC 1.4.1.14) in the unexpanced leaf blades and young grains of rice (Oryza sativa L.) was investigated using tissue-print immunoblot and immunocytological methods with an affinity-purified anti-NADH-GOGAT immunoglobulin G. Tissue-print immunoblots showed that the NADH-GOGAT protein was mostly located in large and small vascular bundles of the unexpanded blades. When the cross-sections (10μ in thickness) prepared from the paraffin-embedded blades were stained with the antibody, the NADH-GOGAT protein was detected in vascular-parenchyma cells and mestome-sheath cells. In developing grains, the NADH-GOGAT protein was detected in both phloem- and xylem-parenchyma cells of dorsal and lateral vascular bundles, and in the nucellar projection, nucellar epidermis, and aleurone cells. On the other hand, ferredoxin (Fd)-dependent GOGAT (EC 1.4.7.1) was located mainly in mesophyll cells of the leaf blade and in chloroplast-containing cross-cells of the pericarp of the grains. The spatial expression of these GOGAT proteins indicates distinct and non-overlapping roles in rice plants. In the leaf blades and young grains, NADH-GOGAT could be involved in the synthesis of glutamate from the glutamine that is transported through the vascular system from roots and senescing tissues.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00201826
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