A role of catalase (CAT) in detoxification of reactive oxygen species (ROS) in tomato (Lycopersicum esculentum) contaminated with manganese (Mn super(2+))

In the current study, tomato (Lycopersicum esculentum L.) plants were exposed to various concentrations of Mn super(2+) (80, 160, 320, 640 and 1280 mu M) cation. In the first part, in order to obtain evidence that plants were in stress, following the Mn super(2+) treatments, lipid peroxidation were determined. In the second part, to gain an idea about regulation of the CAT gene product, enzyme activities were also recorded in Mn super(2+) treated tomato plants. The maximum lipid peroxidation level was determined in plants which were exposed to 1280 mu M concentration of Mn super(2+) contamination. Changes in lipid peroxidation and CAT enzyme activities in tomato plants exposed to different concentration of Mn super(2+) contamination revealed no positive correlation. The current study revealed that, ROS induced lipid peroxidation level has depended on concentration of Mn super(2+) contamination. Also, antioxidant responses to Mn super(2+) contamination could be reflected as changes in CAT enzyme activity in tomato plants.Original Abstract: Bu calismada, domates bitkileri (Lycopersicum esculentum L.) cesitli konsantrasyonlardaki (80, 160, 320, 640 ve 1280 [mu]M) Mn super(2+) katyonuna maruz birakilmistir. Calismanin ilk bolumunde Mn super(2+) stresini takiben bitkilerin stres etkisine gitmis olduklarini gostermek icin lipit peroksidasyonu duzeyleri belirlenmistir. Ikinci bolumde CAT gen urununun regulasyonu degerlendirmek icin Mn super(2+) stresli domates bitkilerinde enzim aktivitesi olculmustur. En yuksek lipit peroksidasyonu 1280 [mu]M konsantrasyonda Mn super(2+) stresine maruz kalan bitkilerde gozlenmistir. Farkli konsantrasyonlardaki Mn super(2+) stresi altindaki domates bitkisinde lipit peroksidasyonu ve CAT enzim aktivitesi duzeyleri arasinda pozitif bir korelasyona rastlanmamistir. Bu calisma ile ROS ile tetiklenen lipit peroksidasyonu seviyesinin Mn super(2+) stresinin konsantrasyonuna bagli oldugu belirlenmistir. Ayni zamanda Mn super(2+) stresine karsi olusan antioksidan cevaplarin domates bitkisinde CAT enzim aktivitesinin degisimi olarak yansiyabildigi gozlenmistir.