the effect of silver thiosulfate (sts) on chlorophyll content and the antioxidant

potato (solanum tuberosum l.) auxiliary buds c.v. white desiree were cultured in ms medium containing 0, 50, 100, 150 and 200 μm concentrations of silver thiosulfate (sts) under in vitro condition. after eight weeks, the effect of silver ions (ag+) in the form of silver thiosulfate complex (sts), as an ethylene action inhibitor, on chlorophyll contents of leaves, ascorbate peroxidase, guaiacol peroxidase and catalase activities of roots and leaves were studied. application of silver (sts) in culture medium increased chlorophyll content comparing to the control plants significantly. after treatments of potato plants with sts, ascorbate peroxidase and guaiacol peroxidase activities in roots were higher than shoots while catalase activity was higher in leaves than roots. however, increasing of sts concentration in the culture medium resulted in higher activities of antioxidant enzymes with some variations.