Linked Life Data

17507103

Source:http://linkedlifedata.com/resource/pubmed/id/17507103

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-5-22
pubmed:abstractText
Algal communities play a crucial role in aquatic food webs by facilitating the transfer of dissolved inorganic selenium (both an essential trace element and a toxic compound for a wide variety of organisms) to higher trophic levels. The dominant inorganic chemical species of selenium in freshwaters are selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)). At environmental concentrations, selenite is not likely to have direct toxic effects on phytoplankton growth [Morlon, H., Fortin, C., Floriani, M., Adam, C., Garnier-Laplace, J., Boudou, A., 2005a. Toxicity of selenite in the unicellular green alga Chlamydomonas reinharditii: comparison between effects at the population and sub-cellular level. Aquat. Toxicol. 73(1), 65-78]. The effects of selenate, on the other hand, are poorly documented. We studied the effects of selenate on Chlamydomonas reinhardtii growth (a common parameter in phytotoxicity tests). Growth inhibition (96-h IC(50)) was observed at 4.5+/-0.2 microM selenate (p<0.001), an effective concentration which is low compared to environmental concentrations. Growth inhibition at high selenium concentrations may result from impaired photosynthesis. This is why we also studied the effects of selenate on the photosynthetic process (not previously assessed in this species to our knowledge) as well as selenate's effects on cell ultrastructure. The observed ultrastructural damage (chloroplast alterations, loss of appressed domains) confirmed that chloroplasts are important targets in the mechanism of selenium toxicity. Furthermore, the inhibition of photosynthetic electron transport evaluated by chlorophyll fluorescence induction confirmed this hypothesis and demonstrated that selenate disrupts the photosynthetic electron chain. Compared to the classical 'growth inhibition' parameter used in phytotoxicity tests, cell diameter and operational photosynthetic yield were more sensitive and may be convenient tools for selenate toxicity assessment in non-target plants.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0166-445X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
149-58
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Effect of selenate on growth and photosynthesis of Chlamydomonas reinhardtii.
pubmed:affiliation
Laboratoire de Radioécologie et Ecotoxicologie, Institut de Radioprotection et Sûreté Nucléaire, Cadarache, Saint-Paul-lez-Durance Cedex, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't