Ağır metal stresi koşullarında Verbascum olympicum Boiss. türünün enzimatik aktivitesi üzerinde araştırmalar
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Date
2017-03-09
Authors
Akpınar, Ayşegül
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Publisher
Uludağ Üniversitesi
Abstract
Bu çalışmada Uludağ'ın sub-alpin ve alpin kuşağındaki bozulmuş alanlarda egemen olan ruderal bitki Verbascum olympicum Boiss. (Sığır kuyruğu)'a ait fideler laboratuvar koşullarında (gece/gündüz sıcaklığı 15°C/25°C, 16 saat ışık/8 saat karanlık periyot) Hoagland besin çözeltisinde yetiştirilerek farklı konsantrasyon ve sürelerde kadmiyum (Cd), krom (Cr), bakır (Cu), nikel (Ni) ve çinko (Zn) uygulamasına maruz bırakılmıştır. Örnekleme dönemlerinde hasat edilen, metal uygulanmış ve uygulanmamış (kontrol grubu) fidelerin kök ve yapraklarında biyokütle (mg KA), su içeriği (%), eriyebilir protein içeriği (mg g-1), lipid peroksidasyonu (MDA içeriği, nmol/g YA), hücre membran zararı (%), iyon sızıntısı (%), azot metabolizması (Nitrat redüktaz: NR, Glutamin sentetaz: GS) ve antioksidatif savunma sistemi enzimlerinin (Süperoksitdismutaz: SOD, Askorbat peroksidaz: APX ve Katalaz: CAT) aktivitesi tayin edilmiştir. Ayrıca yaprak kısımlarında klorofil içeriği (klorofil a, b ve total klorofil; mg/g YA) belirlenmiştir. Elde edilen veriler İki-Yönlü (Two-Way ANOVA) varyans testi ile analiz edilmiştir (α:0,05). Araştırılan metallerin çoğunlukla konsantrasyon ve uygulama süresine bağlı olarak biyokütle, su içeriği, eriyebilir protein ve klorofil içeriğinde azalışa, MDA, hücre membran zararı ve iyon sızıntısında artışa neden olduğu tespit edilmiştir. Nitrat redüktaz ve glutamin sentetazın metal uygulamalarından genellikle olumsuz etkilendiği, buna karşın antioksidatif savunma sistemi enzimlerinin (SOD, APX ve CAT) aktivitesinin uygulama süresi ve konsantrasyona bağlı olarak artma eğiliminde olduğu belirlenmiştir. Bu sonuçlar V. olympicum'un ağır metal stresinden bir dereceye kadar etkilenmesine rağmen ağır metaller ile başa çıkmak için güçlü bir antioksidatif savunma sistemine sahip olduğunu ve Uludağ'da bozulmuş alanlarda gelişip sekonder süksesyon sürecindeki rolünü ortaya koymaktadır.
In this study, the seedlings of ruderal Verbascum olympicum Boiss. which is dominated in areas of sub-alpine and alpine belts of Uludag Mountain were grown in Hoagland nutrient solution with controlled conditions (day/night temperature 15°C/25°C, 16 h light/8 h dark) and they were treated with different concentrations and durations of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn). Biomass (mg DW), water content (%), chlorophyll content (chlorophyll a, b and total chlorophyll; mg/g FW), lipid peroxidation (MDA content, nmol/g FW), electrolyte leakage (%) and cell membrane damage (%) with the changes in the enzyme activities of nitrogen metabolism (Nitrate reductase: NR, Glutamine synthetase: GS) and antioxidative defence system (Superoxidedismutase: SOD, Askorbate peroxidase: APX and Catalase: CAT) in root and leaves of the metal treated and control plants. Chlorophyll content was also determined in leaves. The differences among the means of values for examined parameters according to different metal concentrations and exposure periods by a Two-Way ANOVA (α:0,05). It was generally found that biomass, water content, chlorophyll content and protein content was decreased, MDA, electrolyte leakage and cell membrane damage were increased depending on concentration and duration in examined metals. Nitrate reductase and glutamine synthetase activities were negatively affected by metal treatments, whereas it was determined an increase tendency in antioxidative defence system enzyme (SOD, CAT, APX) activities. It can be concluded that although V. olympicum was affected to a certain extent from metal treatments, it has a powerful antioxidative defence system to cope with heavy metal stress and it has an important role in seconder succession on Uludag disturbed areas via this properties.
In this study, the seedlings of ruderal Verbascum olympicum Boiss. which is dominated in areas of sub-alpine and alpine belts of Uludag Mountain were grown in Hoagland nutrient solution with controlled conditions (day/night temperature 15°C/25°C, 16 h light/8 h dark) and they were treated with different concentrations and durations of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn). Biomass (mg DW), water content (%), chlorophyll content (chlorophyll a, b and total chlorophyll; mg/g FW), lipid peroxidation (MDA content, nmol/g FW), electrolyte leakage (%) and cell membrane damage (%) with the changes in the enzyme activities of nitrogen metabolism (Nitrate reductase: NR, Glutamine synthetase: GS) and antioxidative defence system (Superoxidedismutase: SOD, Askorbate peroxidase: APX and Catalase: CAT) in root and leaves of the metal treated and control plants. Chlorophyll content was also determined in leaves. The differences among the means of values for examined parameters according to different metal concentrations and exposure periods by a Two-Way ANOVA (α:0,05). It was generally found that biomass, water content, chlorophyll content and protein content was decreased, MDA, electrolyte leakage and cell membrane damage were increased depending on concentration and duration in examined metals. Nitrate reductase and glutamine synthetase activities were negatively affected by metal treatments, whereas it was determined an increase tendency in antioxidative defence system enzyme (SOD, CAT, APX) activities. It can be concluded that although V. olympicum was affected to a certain extent from metal treatments, it has a powerful antioxidative defence system to cope with heavy metal stress and it has an important role in seconder succession on Uludag disturbed areas via this properties.
Description
Keywords
Ağır metal, Ruderal, Uludağ, Nitrat redüktaz, Glutamin sentetaz, Süperoksit dismutaz, Katalaz, Askorbat peroksidaz, Verbascum olympicum, Heavy metals, Uludag, Nitrate reductase, Glutamine synthetase, Superoxide dismutase, Catalase, Ascorbate peroxidase
Citation
Akpınar, A. (2017). Ağır metal stresi koşullarında Verbascum olympicum Boiss. türünün enzimatik aktivitesi üzerinde araştırmalar. Yayınlanmamış doktora tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.