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Titolo:
Spatial and temporal expression of two cytosolic glutamine synthetase genes in Scots pine: functional implications on nitrogen metabolism during early stages of conifer development
Autore:
Avila, C; Suarez, MF; Gomez-Maldonado, J; Canovas, FM;
Indirizzi:
Univ Malaga, Fac Ciencias, Dept Bioquim & Biol Mol, E-29071 Malaga, Spain Univ Malaga Malaga Spain E-29071 oquim & Biol Mol, E-29071 Malaga, Spain Univ Malaga, Fac Ciencias, Inst Andaluz Biotecnol, E-29071 Malaga, Spain Univ Malaga Malaga Spain E-29071 ndaluz Biotecnol, E-29071 Malaga, Spain
Titolo Testata:
PLANT JOURNAL
fascicolo: 1, volume: 25, anno: 2001,
pagine: 93 - 102
SICI:
0960-7412(200101)25:1<93:SATEOT>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
EARLY-SEEDLING GROWTH; TAEDA L. SEEDS; BIOCHEMICAL-CHANGES; PROTEIN-SYNTHESIS; HIGHER-PLANTS; ASSIMILATION; SYLVESTRIS; ISOFORMS; DEHYDROGENASE; LOCALIZATION;
Keywords:
N metabolism; cytosolic glutamine synthetase; conifer; gene expression; gene family; in situ hybridization;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
43
Recensione:
Indirizzi per estratti:
Indirizzo: Canovas, FM Univ Malaga, Fac Ciencias, Dept Bioquim & Biol Mol, Campus Univ Teatinos S-N, E-29071 Malaga, Spain Univ Malaga Campus Univ Teatinos S-N Malaga Spain E-29071 ain
Citazione:
C. Avila et al., "Spatial and temporal expression of two cytosolic glutamine synthetase genes in Scots pine: functional implications on nitrogen metabolism during early stages of conifer development", PLANT J, 25(1), 2001, pp. 93-102

Abstract

Ammonium assimilation during the initial stages of Scots pine growth involves two cytosolic glutamine synthetase (GS, EC: 6.3.1.2) isoenzymes encodedby separate genes, GS1a and GS1b. GS1a was most exclusively expressed in photosynthetic tissues of the seedling whereas GS1b was expressed ubiquitously showing higher levels in non-photosynthetic tissues such as root and hypocotyl. Temporal expression analysis has shown that when germination startsGS1b is the predominant form in the embryo, however, its relative abundance in the tissue decreased in the postgerminative stages when green cotyledons are developed. In contrast GS1a was present at a low level in the embryobut its abundance increased markedly during germination and seedling growth. These data suggest that GS1a and GS1b genes display different and non-redundant roles in the nitrogen metabolism of conifers. The precise localization of individual transcripts by in situ hybridization strongly supports this possibility. GS1 gene products are mainly expressed in different cellular types: GS1a in chlorophylic parenchyma and GS1b in the vascular bundles of all tissues examined in the seedling. Our data support that glutamine biosynthesis in pine seedlings follows a different pattern related to angiosperms involving two cytosolic GS proteins: one of them a typical cytosolic GSwhich may be involved in the generation of glutamine for N transport and asecond cytosolic GS generating amino donors for the biosynthesis of major N compounds in photosynthetic tissues, a closer role to angiosperm chloroplastic GS. The results are discussed with regard to recent studies on N mobilization and metabolism during the initial stages of conifer development.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/10/20 alle ore 16:09:23