Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-3-14
pubmed:abstractText
Three-year-old beech (Fagus sylvatica) seedlings growing in containers were placed into the sun and shade crown of a mature beech stand exposed to ambient (1 x O(3)) and double ambient (2 x O(3)) ozone concentrations at a free-air exposure system ("Kranzberg Forst", Germany). Pigments, alpha-tocopherol, glutathione, ascorbate, and gas exchange were measured in leaves during 2003 (a drought year) and 2004 (an average year). Sun-exposed seedlings showed higher contents of antioxidants, xanthophylls, and beta-carotene and lower contents of chlorophyll, alpha-carotene, and neoxanthin than shade-exposed seedlings. In 2003 sun-exposed seedlings showed higher contents of carotenoids and total glutathione and lower net photosynthesis rates (A(max)) compared to 2004. O(3) exposure generally affected the content of chlorophyll, the xanthophyll cycle, and the intercellular CO(2) concentration (c(i)). Seedlings differed from the adjacent adult trees in most biochemical and physiological parameters investigated: Sun exposed seedlings showed higher contents of alpha-tocopherol and xanthophylls and lower contents of ascorbate, chlorophyll, neoxanthin, and alpha-carotene compared to adult trees. Shade exposed seedlings had lower contents of xanthophylls, alpha-carotene, and alpha-tocopherol than shade leaves of old-growth trees. In 2003, seedlings had higher A(max), stomatal conductance (g(s)), and c(i) under 2 x O(3) than adult trees. The results showed that shade acclimated beech seedlings are more sensitive to O(3), possibly due to a lower antioxidative capacity per O(3) uptake. We conclude that beech seedlings are uncertain surrogates for adult beech trees.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1435-8603
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
288-97
pubmed:dateRevised
2008-1-7
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Gas exchange and antioxidative compounds in young beech trees under free-air ozone exposure and comparisons to adult trees.
pubmed:affiliation
Institut für Pflanzenwissenschaften, Universität Graz, Schuberstrasse 51, 8010 Graz, Austria. karin.herbinger@uni-graz.at
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't