Linked Life Data

16971389

Source:http://linkedlifedata.com/resource/pubmed/id/16971389

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
45
pubmed:dateCreated
2006-11-6
pubmed:abstractText
The metabolism of developing plant seeds is directed toward transforming primary assimilatory products (sugars and amino acids) into seed storage compounds. To understand the role of mitochondria in this metabolism, metabolic fluxes were determined in developing embryos of Brassica napus. After labeling with [1,2-(13)C2]glucose + [U-(13)C6]glucose, [U-(13)C3]alanine, [U-(13)C5]glutamine, [(15)N]alanine, (amino)-[(15)N]glutamine, or (amide)-[(15)N]glutamine, the resulting labeling patterns in protein amino acids and in fatty acids were analyzed by gas chromatography-mass spectrometry. Fluxes through mitochondrial metabolism were quantified using a steady state flux model. Labeling information from experiments using different labeled substrates was essential for model validation and reliable flux estimation. The resulting flux map shows that mitochondrial metabolism in these developing seeds is very different from that in either heterotrophic or autotrophic plant tissues or in most other organisms: (i) flux around the tricarboxylic acid cycle is absent and the small fluxes through oxidative reactions in the mitochondrion can generate (via oxidative phosphorylation) at most 22% of the ATP needed for biosynthesis; (ii) isocitrate dehydrogenase is reversible in vivo; (iii) about 40% of mitochondrial pyruvate is produced by malic enzyme rather than being imported from the cytosol; (iv) mitochondrial flux is largely devoted to providing precursors for cytosolic fatty acid elongation; and (v) the uptake of amino acids rather than anaplerosis via PEP carboxylase determines carbon flow into storage proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34040-7
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:16971389-Acetyl Coenzyme A, pubmed-meshheading:16971389-Amino Acids, pubmed-meshheading:16971389-Brassica napus, pubmed-meshheading:16971389-Carbohydrate Metabolism, pubmed-meshheading:16971389-Carbon, pubmed-meshheading:16971389-Carbon Isotopes, pubmed-meshheading:16971389-Citric Acid Cycle, pubmed-meshheading:16971389-Culture Techniques, pubmed-meshheading:16971389-Cytosol, pubmed-meshheading:16971389-Fatty Acids, pubmed-meshheading:16971389-Gas Chromatography-Mass Spectrometry, pubmed-meshheading:16971389-Glucose, pubmed-meshheading:16971389-Glycolysis, pubmed-meshheading:16971389-Isotope Labeling, pubmed-meshheading:16971389-Malates, pubmed-meshheading:16971389-Mitochondria, pubmed-meshheading:16971389-Models, Biological, pubmed-meshheading:16971389-Oxidative Phosphorylation, pubmed-meshheading:16971389-Protein-Serine-Threonine Kinases, pubmed-meshheading:16971389-Pyruvic Acid, pubmed-meshheading:16971389-Seeds
pubmed:year
2006
pubmed:articleTitle
Mitochondrial metabolism in developing embryos of Brassica napus.
pubmed:affiliation
Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA. Schwender@BNL.gov
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.