The Protection Of Exogenous Putrescine To The Oxidative Damage Induced By Salt Stress In Wheat Roots

Salt stress is one of the most serious factors limiting the productivity of agricultural crops.Polyamines play an important role in the plant response to adverse environmental conditions.To clarify the involvement of exogenous Put in the salt stress response,the content of TBARS,electrolyte leakage,the accumulation and scavenging of ROS,Na⁺/K⁺ ratio,and the activities of DAO and PAO were investigated in wheat(T.aestivm L.)roots which treated with exogenous Put under salt stress.The results demonstrated that exogenous Put alleviate the oxidative damage by increasing the activities of antioxidant enzymes and decreasing lipid peroxidation. Exogenous Put is effective in increasing the activities of superoxide dismutase(SOD), ascorbate peroxidase(APX)and Peroxidase(POD),the content of reduced glutathione(GSH),proline and soluble sugar,reducing the content of TBARS, electrolyte leakage,the accumulation of O₂^?,the ratio of Na⁺/K⁺.However,when the wheat was treated with exogenous Put under salt stress,the content of H₂O₂ increased. This is probably relation to the increased activities of DAO and PAO,which produce H₂O₂.Sum up,exogenous application of Put could alleviate the oxidative damage induced by salt stress.The protection of Put in salt stress may be due to increase the activities of antioxidant enzymes,the accumulation of osmotic substances and decrease the ratio of Na⁺/K⁺ in wheat roots.