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Titolo:
Differential regulation of three functional ammonium transporter genes by nitrogen in root hairs and by light in leaves of tomato
Autore:
von Wiren, N; Lauter, FR; Ninnemann, O; Gillissen, B; Walch-Liu, P; Engels, C; Jost, W; Frommer, WB;
Indirizzi:
Zentrum Mol Biol Pflanzen Tubingen, D-72076 Tubingen, Germany Zentrum Mol Biol Pflanzen Tubingen Tubingen Germany D-72076 gen, Germany Univ Hohenheim, Inst Pflanzenernahrung, D-70593 Stuttgart, Germany Univ Hohenheim Stuttgart Germany D-70593 ung, D-70593 Stuttgart, Germany
Titolo Testata:
PLANT JOURNAL
fascicolo: 2, volume: 21, anno: 2000,
pagine: 167 - 175
SICI:
0960-7412(200001)21:2<167:DROTFA>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHLOROPLAST GLUTAMINE-SYNTHETASE; AFFINITY NITRATE TRANSPORTERS; ARABIDOPSIS-THALIANA; SERINE HYDROXYMETHYLTRANSFERASE; SACCHAROMYCES-CEREVISIAE; PHASEOLUS-VULGARIS; APOPLASTIC NH4+; HIGHER-PLANTS; OILSEED RAPE; RICE ROOTS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
48
Recensione:
Indirizzi per estratti:
Indirizzo: von Wiren, N Zentrum Mol Biol Pflanzen Tubingen, Morgenstelle 1, D-72076 Tubingen, Germany Zentrum Mol Biol Pflanzen Tubingen Morgenstelle 1 Tubingen Germany D-72076
Citazione:
N. von Wiren et al., "Differential regulation of three functional ammonium transporter genes by nitrogen in root hairs and by light in leaves of tomato", PLANT J, 21(2), 2000, pp. 167-175

Abstract

To elucidate the role of NH4+ transporters in N nutrition of tomato, two new NH4+ transporter genes were isolated from cDNA libraries of root hairs or leaves of tomato. While LeAMT1;2 is closely related to LeAMT1;1 (75.6% amino acid identity), LeAMT1;3 is more distantly related (62.8% identity) andpossesses two short upstream open reading frames in the 5' end of the mRNAand a particularly short N-terminus of the protein as unique features. When expressed in yeast mutants defective in NH4+ uptake, all three genes complemented NH4+ uptake. In roots of hydroponically grown plants, transcript levels of LeAMT1;2 increased after NH4+ or NO3- supply, while LeAMT1;1 was induced by N deficiency coinciding with low glutamine concentrations, and LeAMT1;3 was not detected. In aeroponic culture, expression of LeAMT1;1 and LeAMT1;2 was higher in root hairs than in the remaining root fraction. Growth of plants at elevated CO2 slightly decreased expression of LeAMT1;2 and LeAMT1;3 in leaves, but strongly repressed transcript levels of chloroplast glutamine synthetase and photorespiratory serine hydroxymethyl-transferase. Expression of LeAMT1;2 and LeAMT1;3 showed a reciprocal diurnal regulationwith highest transcript levels of LeAMT1;3 in darkness and highest levels of LeAMT1;2 after onset of light. These results indicate that in tomato at least two high-affinity NH4+ transporters, LeAMT1;1 and LeAMT1;2, are differentially regulated by N and contribute to root hair-mediated NH4+ acquisition from the rhizosphere. In leaves, the reciprocally expressed transporters LeAMT1;2 and LeAMT1;3 are supposed to play different roles in N metabolism, NH4+ uptake and/or NH3 retrieval during photorespiration.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/07/20 alle ore 21:02:00