Linked Life Data

10743657

Source:http://linkedlifedata.com/resource/pubmed/id/10743657

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-6-5
pubmed:databankReference
pubmed:abstractText
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) and possesses two short upstream open reading frames in the 5' end of the mRNA and 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 regulation with 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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-75
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10743657-Amino Acid Sequence, pubmed-meshheading:10743657-Biological Transport, pubmed-meshheading:10743657-Carrier Proteins, pubmed-meshheading:10743657-Cation Transport Proteins, pubmed-meshheading:10743657-Circadian Rhythm, pubmed-meshheading:10743657-Gene Expression Regulation, Plant, pubmed-meshheading:10743657-Glutamate-Ammonia Ligase, pubmed-meshheading:10743657-Light, pubmed-meshheading:10743657-Lycopersicon esculentum, pubmed-meshheading:10743657-Molecular Sequence Data, pubmed-meshheading:10743657-Nitrogen, pubmed-meshheading:10743657-Plant Leaves, pubmed-meshheading:10743657-Plant Proteins, pubmed-meshheading:10743657-Plant Roots, pubmed-meshheading:10743657-Quaternary Ammonium Compounds, pubmed-meshheading:10743657-Saccharomyces cerevisiae, pubmed-meshheading:10743657-Sequence Alignment
pubmed:year
2000
pubmed:articleTitle
Differential regulation of three functional ammonium transporter genes by nitrogen in root hairs and by light in leaves of tomato.
pubmed:affiliation
Zentrum für Molekularbiologie der Pflanzen Tübingen (ZMBP), Tübingen.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't