Linked Life Data

10938793

Source:http://linkedlifedata.com/resource/pubmed/id/10938793

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
342
pubmed:dateCreated
2000-8-25
pubmed:abstractText
Legumes obtain a substantial portion of their nitrogen (N) from symbiotic N2 fixation in root nodules. The glutamine synthetase (GS, EC 6.3.1.2)/glutamate synthase (GOGAT) cycle is responsible for the initial N assimilation. This report describes the analysis of a transgenic alfalfa (Medicago sativa L.) line containing an antisense NADH-GOGAT (EC 1.4.1.14) under the control of the nodule-enhanced aspartate amino-transferase (AAT-2) promoter. In one transgenic line, NADH-GOGAT enzyme activity was reduced to approximately 50%, with a corresponding reduction in protein and mRNA. The transcript abundance for cytosolic GS, ferredoxin-dependent GOGAT (EC 1.4.7.1), AAT-2 (EC 2.6.1.1), asparagine synthase (EC 6.3.5.4), and phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) were unaffected, as were enzyme activities for AAT, PEPC and GS. Antisense NADH-GOGAT plants grown under symbiotic conditions were moderately chlorotic and reduced in growth and N content, even though symbiotic N2 fixation was not significantly reduced. The addition of nitrate relieved the chlorosis and restored growth and N content. Surprisingly, the antisense NADH-GOGAT plants were male sterile resulting from inviable pollen. A reduction in NADH-GOGAT enzyme activity and transcript abundance in the antisense plants was measured during the early stages of flower development. Inheritance of the transgene was stable and resulted in progeny with a range of NADH-GOGAT activity. These data indicate that NADH-GOGAT plays a critical role in the assimilation of symbiotically fixed N and during pollen development.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-0957
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29-39
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Decreased NADH glutamate synthase activity in nodules and flowers of alfalfa (Medicago sativa L.) transformed with an antisense glutamate synthase transgene.
pubmed:affiliation
Department of Agromomy and Plant Genetics, University of Minnesota, St Paul 55108, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.