Linked Life Data

16325302

Source:http://linkedlifedata.com/resource/pubmed/id/16325302

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-3-20
pubmed:abstractText
Photosynthesis operates in a constantly shifting balance between efficient capture of solar energy and its rapid dissipation when captured in excess. In an attempt to better understand the role of alpha-tocopherol in plant photoprotection, we examined the changes in alpha-tocopherol quinone (alpha-TQ), in parallel with those of other low-molecular-weight antioxidants, in rosemary plants exposed to water deficit during a Mediterranean winter. Relative leaf water content (RWC) decreased from about 85% to approximately 65% in drought, but plants did not show symptoms of oxidative damage, as indicated by constant Fv/Fm ratios and malondialdehyde (MDA) levels. alpha-TQ was present at concentrations of 20 mmol per 100 mol of chlorophyll, and represented less than 1% of total tocopherol content in non-stressed leaves. Although alpha-tocopherol levels were not significantly altered, alpha-TQ reached up to 36 mmol per 100 mol of chlorophyll under stress (under both high light and after exposure to increasing water deficit at lower light intensities). Furthermore, both alpha-TQ and xanthophyll cycle de-epoxidation were strongly negatively correlated with the relative efficiency of photosystem II photochemistry (phiPSII) at midday. The biological significance of alpha-tocopherol and alpha-TQ in the network of photo- and antioxidative protection mechanisms evolved by plants to withstand stress is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0176-1617
pubmed:author
pubmed:issnType
Print
pubmed:volume
163
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
601-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Enhanced alpha-tocopherol quinone levels and xanthophyll cycle de-epoxidation in rosemary plants exposed to water deficit during a Mediterranean winter.
pubmed:affiliation
Departament de Biologia Vegetal, Universitat de Barcelona, Facultat de Biologia, Avinguda Diagonal 645, 08028 Barcelona, Spain.
pubmed:publicationType
Journal Article