Change Law of Main Protective Enzyme Activity in Kernel-apricot Leaves in Different Growth Stage

Objective The purpose was to study the stress resistance mechanism of Kernel-apricot.Method With leaves collected from developed well 5-year-old Kernel-apricot seedlings as tested materials,the seedlings were treated with copper and zinc spraying in their hardening,initial growing and fast-growing stages.The activities of superoxide dismutase(SOD)and polyphenol oxidase(PPO)in Kernel-apricot leaves were determined by NBT reduction method and pyrocatechol method.The change laws of main protective enzyme PPO and SOD activity in Kernel-apricot leaves in different growth periods were analyzed.Result The PPO activity in Kernel-apricot leaves treated with Cu(3)Zn(0)increased significantly and was also kept at higher level in hardening stage.Treating Kernel-apricot leaves with Cu(0)Zn(3)increased PPO activity very little,even had decreasing effect it.The SOD activity in Kernel-apricot leaves treated with Cu(0)Zn(3)was increased significantly,and being obviously higher in the initial growth stage than in the hardening and fast-growing stages.Conclusion Zinc has more significant strengthening effect on SOD activity in Kernel-apricot leaves.Copper and zinc affect the growth of Kernel-apricot seedlings through changing PPO and SOD activities,accordingly increase the stress resistance of seedlings.