Effects of Exogenous Salicylic Acid on Production of ROS and Changes in Activity of Antioxidant Enzymes in Wheat Seedlings under Cu~(2+) Stress

Effects of exogenous salicylic acid(SA) on production of reactive oxygen species(ROS) and changes in activity of the main antioxidant enzymes,superoxide dismutase,catalase,ascorbate peroxidase and glutathione reductase in wheat seedlings under Cu2+ stress were studied.The results showed that Cu2+ resulted in significant increase in content of malondialdehyde,level of ROS and activity of the four enzymes above in wheat roots and leaves in comparison with the control.SA treatment obviously enhanced the antioxidant enzyme activities and alleviated the ROS level induced by Cu2+ in leaves.The change pattern at ROS level in roots was similar to that in leaves.However,the change of antioxidant enzyme activity in the two organs was different.These findings suggest that SA may trigger activity of the antioxidant enzymes at early periods to alleviate oxidative damage induced by Cu2+ and the four enzymes may play different protective roles in wheat roots and leaves.