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1	Effect Of Cold Stress On Antioxidant Mechanism Of Winter And Spring Type Barley ( Hordeum Vulgare L.) Cultivars Afsar, Nilufer 01 July 2007 (has links) (PDF) In this study, effect of cold stress on physiology and biochemistry of two Turkish barley cultivars, winter type Tarm-92 and spring type Zafer-160, was studied. For chilling stress treatment, cultivars were exposed to +4 &ordm / C for 1, 3 and 7 days, and for freezing stress application acclimated cultivars (+4 &ordm / C for 3 days) were treated with -3 &ordm / C and -7 &ordm / C. After freezing stress treatment, a recovery period was applied for 4 days at 4 &ordm / C. Following analyses were performed on leaf and root tissues: growth parameters (length, wet-dry weights), malondialdehyde (MDA) content, proline content, hydrogen peroxide content (H2O2) electrolyte leakage, PS II fluorescence (Fv/Fm), antioxidant enzyme activities such as catalase (CAT: EC 1.11.1.6), ascorbate peroxidase (APX: EC 1.11.1.11) and glutathione reductase (GR: EC 1.6.4.2). It was observed that effect of cold was more at freezing temperatures than chilling temperature. Cold dependent damage was more obvious as the duration of chilling temperature increased. Growth retardation, membrane damage, leaf catalase deactivation were more apparent and leaf glutathione reductase activity increase was less in spring type cultivar Zafer than in winter type Tarm. These results indicated that winter type barley cultivar is more cold tolerant than spring type barley. Q General Science 1-385
2	Antioxidant enzyme activities in fluvial biofilms as biomakers of metal pollution Bonet Sánchez, Berta 28 February 2013 (has links) The present thesis aims to evaluate the use of antioxidant enzyme activities (AEA) of biofilm communities as biomarkers of metal pollution (mainly Zn) in fluvial ecosystems. In order to test AEA as biomarkers of metal pollution as well as their responses to environmental variables, several ecotoxicological experiments have been performed. A zoom from field studies (with high ecological realism) to microcosm experiments (under controlled conditions) has been done to fill the gap between both approaches and understand AEA responses under a multiple-stress (environmental and metallic) scenario. The field studies were carried out in the Riera d’Osor, a tributary of the Ter, located in the region of La Selva (Girona province) / L’objectiu d’aquesta tesi és avaluar l’ús de les activitats enzimàtiques antioxidants (AEA) dels biofilms com a biomarcadors de contaminació metàl·lica (principalment per zinc (Zn)) en els ecosistemes fluvials. Per tal d’estudiar la resposta de les AEA a la contaminació metàl•lica, així com també la resposta a altres canvis ambientals (situacions d’estrès múltiple), s’han realitzat diversos experiments ecotoxicològics fent un zoom des d’estudis de camp (amb un elevat realisme ecològic) fins a un estudi de laboratori utilitzant microcosmos (amb condicions controlades). Els estudis de camp s’han dut a terme a la riera d’Osor, afluent del Ter, situada a la comarca de la Selva (província de Girona) Activitats enzimàtiques antioxidants Actividades enzimáticas antioxidantes Antioxidant enzyme activities Estrès oxidatiu Estrés oxidativo Oxidative stress Zinc Cinc Zn Ecotoxicologia Ecotoxicología Ecotoxicology Ecosistemes fluvials Ecosistemas fluviales Fluvial ecosystems Contaminació per metalls Contaminación por metales Metal pollution 574

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Effect Of Cold Stress On Antioxidant Mechanism Of Winter And Spring Type Barley ( Hordeum Vulgare L.) Cultivars

Antioxidant enzyme activities in fluvial biofilms as biomakers of metal pollution