Some Biochemical Properties of Catalase from Safflower (Carthamus tinctorius L.cv. I

Safflower, Carthamus tinctorius L., is a member of Asteraceae, cultivated mainly for itsseed and flower, which are used as edible oil and for medicinal applications. Safflower is aresistant plant to the environmental stresses; therefore scientists use this plant as a modelfor studying the mechanism of plant resistance to the environmental stresses. Antioxidantenzyme system is one of the defense mechanisms that plants use for various environmental stresses. In this study some biochemical properties of catalase, an antioxidant enzyme system, from safflower and it sensivity to azide and cyanide was investigated. Carthamus tinctorious L.cv.IL-111 was grown hydroponically in perlite for 40 days and catalase was extracted from their leaves using phosphate buffer 0.1 M, pH 7.2. Study of pH profile, temperature and different concentration of substrate and inhibitors (azide and cynide) on catalase activity in Safflower and non-denaturant polyacrylamide gel electrophoresis of crude extract, showed that at least two isoenzymes of catalase were present in safflower leaves with optimal pH at 6.5 and 8.5, respectively. Isoenzyme active at pH 8.5 was more resistant to temperature in comparison to isoenzyme active at pH 6.5. Effects of inhibitors (azide and cynide) on catalase activity showed that isoenzyme active at pH 8.5 was more sensitive to both inhibitors (azide: 4.6 fold, and cynide: 2.6 fold) in comparison to isoenzyme active at pH 6.5.