Linked Life Data

12631328

Source:http://linkedlifedata.com/resource/pubmed/id/12631328

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2003-3-12
pubmed:abstractText
Legumes acquire significant amounts of nitrogen for growth from symbiotic nitrogen fixation. The glutamine synthetase (GS)/NADH-dependent glutamate synthase (NADH-GOGAT) cycle catalyzes initial nitrogen assimilation. This report describes the impact of specifically reducing nodule NADH-GOGAT activity on symbiotic performance of alfalfa (Medicago sativa L.). Four independent transgenic alfalfa lines, designated GA89, GA87, GA88, and GA82 (for GOGATantisense), containing an antisense NADH-GOGAT cDNA fragment under the control of the soybean leghemoglobin (lbc3) promoter were evaluated. The GA plants were fertile and showed normal growth in non-symbiotic conditions. The NADH-GOGAT antisense transgene was heritable and the T1 plants showed phenotypic alterations - similar to primary transformants. Clonally propagated plants were inoculated with Sinorhizobium meliloti after rooting and the symbiotic phenotype was analyzed 21 days post-inoculation. Nodules of each GA line had reduced NADH-GOGAT activity, ranging from 33 to 87% of control plants, that was accompanied by comparable decreases in RNA and protein. Plants from the GA89 line, with the lowest NADH-GOGAT activity (c. 30%), presented a strikingly altered symbiotic phenotype: concomitantly activities of key enzyme for carbon and nitrogen assimilation decreased; nodule amino acids and amides were reduced while sucrose accumulated. Antisense GOGAT plants were chlorotic, reduced in fresh weight, and had a lower N content than control plants. Photosynthesis was also impaired in antisense plants. Specifically, reducing NADH-GOGAT in nodules resulted in plants having impaired nitrogen assimilation and altered carbon/nitrogen metabolic flux.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1037-49
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Antisense inhibition of NADH glutamate synthase impairs carbon/nitrogen assimilation in nodules of alfalfa (Medicago sativa L.).
pubmed:affiliation
Centro de Investigación sobre Fijación de Nitrógeno, UNAM, Ap. Postal 565-A, Cuernavaca, Mor. México.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't