Trace elements and activity of antioxidative enzymes in Cistus ladanifer L. growing on an abandoned mine area.
Ecotoxicology
; 18(7): 860-8, 2009 Oct.
Article
em En
| MEDLINE
| ID: mdl-19499336
ABSTRACT
The Mediterranean shrub Cistus ladanifer grows naturally in São Domingos (Portugal), an abandoned copper mine. High levels of trace elements in plants can generate oxidative stress increasing the activity of antioxidant enzymes. The aim of this work was to evaluate and compare As, Cu, Pb and Zn concentrations and the activity of the soluble and cell wall ionically bounded forms of the enzymes catalase, peroxidase and superoxide dismutase in leaves of C. ladanifer, collected in spring and summer, growing on São Domingos mine and on a non-contaminated area (Pomarão). São Domingos soils showed high total concentrations of As (2.6 g kg(-1)) and Pb (7.3 g kg(-1)) however the available fraction represented less than 1.5% of the total. C. ladanifer population from mine showed tolerance to Pb and Zn, which attain in leaves concentrations considered toxic for plants. The enzymatic activity of catalase, peroxidise and superoxide dismutase varied with plant populations and seasons, although with no particular trend, being specific to each trace element and enzyme cell localization. Catalase activity was evenly distributed between the soluble and ionically bounded forms, whereas the ionically bounded form of peroxidase predominated relatively to total activity, and the opposite was observed for superoxide dismutase. Spring and summer leaves from the two areas presented enzymatic activities in both fractions except to peroxidase soluble activities in leaves collected in summer. C. ladanifer enzymatic activity seems to be related with the co-existence of different stress factors (trace elements concentration, temperature, UV radiation and drought). The survival and growth of this species on contaminated mining soils is due to the presence of effective antioxidant enzyme-based defence systems.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxirredutases
/
Poluentes do Solo
/
Oligoelementos
/
Cistus
/
Resíduos Industriais
País/Região como assunto:
Europa
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article