Linked Life Data

17991025

Source:http://linkedlifedata.com/resource/pubmed/id/17991025

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2007-11-9
pubmed:abstractText
Iron deficiency in axenic cultures of Trichodesmium erythraeum IMS101 led to significant declines in both nitrogen fixation rates and photochemical energy conversion efficiency, accompanied by downregulation of genes encoding the major iron-binding proteins, including psbA and psbE of photosystem II, psaA and psaC of photosystem I, petB and petC of the cytochrome b(6)f complex, and nifH. However, the iron-starved cultures remained viable and expression of the metalloprotein genes was partially or fully restored within 3 days following the addition of iron. Both physiological and molecular responses revealed that expression and synthesis of the nitrogen fixation and photosynthetic machinery follow the hierarchy of iron demand; that is, nitrogen fixation was far more susceptible to iron limitation than photosynthesis. Consequently, the nifH transcript exhibited a 1-2 day shorter half-life and two to three times faster degradation rate than that of the photosynthetic genes. Our results suggest that the changes in gene expression are related to the redox state in the shared photosynthetic/respiratory pathway which, when faced with short-term iron deficiency, signals Trichodesmium to selectively sacrifice nitrogen fixation to conserve iron for photosynthetic and respiratory electron transport. The observed functional and compositional alterations represent the compromises in gene expression and acclimation capacity between two basic metabolic pathways competing for iron when it is limiting.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1462-2912
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2945-56
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Effects of iron limitation on the expression of metabolic genes in the marine cyanobacterium Trichodesmium erythraeum IMS101.
pubmed:affiliation
Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.