不同生长时期冬枣受绿盲蝽危害后应激防御酶活性的变化

【目的】比较绿盲蝽刺吸与人工针刺模拟危害后，冬枣不同组织的应激防御酶活性，以及受绿盲蝽不同程度危害的冬枣叶、蕾、花、幼果应激防御酶的变化。【方法】在冬枣各生长期（芽期、蕾期、花期、幼果期）易受危害部位（嫩叶、蕾、花、幼果）接入不同数量（1—3头）绿盲蝽和人工针刺模拟危害，危害24 h后，采摘不同危害程度的冬枣组织，采用氮蓝四唑法测定超氧化物歧化酶（SOD）活性；采用愈创木酚法测定过氧化物酶（POD）活性；采用紫外吸光法测定过氧化氢酶（CAT）活性。【结果】冬枣嫩叶组织遭人工针刺和绿盲蝽刺吸胁迫后所产生的SOD、POD、CAT活性显著高于正常叶片，其中绿盲蝽刺吸嫩叶所产生的应激SOD和CAT活性显著高于人工针刺；冬枣蕾受到人工针刺和绿盲蝽刺吸胁迫后，SOD活性没有变化，POD活性显著增加，受绿盲蝽刺吸胁迫后CAT活性显著高于人工针刺胁迫；冬枣花受到人工针刺和绿盲蝽刺吸胁迫后，SOD和CAT活性没有变化，POD活性显著增加，绿盲蝽刺吸胁迫下POD活性比人工针刺活性更高；冬枣幼果受到人工针刺和绿盲蝽刺吸胁迫后，SOD和CAT活性没有变化，POD活性显著增加。受绿盲蝽不同危害程度的应激酶活性测定结果表明，受害后冬枣各组织内3种防御性酶随受害程度的加重发生不同程度的变化。叶片和花受绿盲蝽不同程度危害后，SOD活性呈现随着受害程度的加重先升高后降低的趋势；POD、CAT活性随受害程度的加重均呈上升的趋势；冬枣蕾受绿盲蝽不同程度危害后，SOD活性变化不显著，POD和CAT活性呈现上升趋势。冬枣幼果受绿盲蝽不同程度危害后，SOD活性随着受害程度的加重先降低，后上升；POD活性随受害程度的加重均呈先下降再上升的趋势。【结论】绿盲蝽的危害胁迫能诱导寄主植物产生一系列应激生化反应。冬枣不同组织受胁迫后，参与防御的酶可能不同，嫩叶受胁迫后，3种防御酶均会发生变化，而蕾、花、幼果等繁殖器官受胁迫后，POD活性变化更为明显；绿盲蝽刺吸胁迫（除了物理损伤外，还分泌唾液进行化学危害）比人工针刺（仅有物理损伤）往往能够诱导更高的防御酶活性；随着绿盲蝽的危害加重，冬枣不同组织的受损程度不同，不同的酶活性表现不同。

Defense Enzyme Activity of Winter Jujube at Different Stages Induced by the Damage of Apolygus lucorum

【Objective】The objective of this study is to compare the activities of defense enzymes in different tissues of winter jujube induced by the damage of Apolygus lucorum and artificial needling, and to observe the changes of stress defense activities of enzymes in leaves, buds, flowers and young fruits with different levels of damage by A. Lucorum. 【Method】The experiments were conducted with vulnerable jujube tissues inoculation, artificial simulated needling, counting damage spots after 24 hours, then the damaged tissues were sampled. The activities of SOD, POD and CAT were determined by nitroblue tetrazolium method, guaiacol method and ultraviolet absorbance method, respectively.【Result】The activity of defense enzymes was changed with different damages. The activities of SOD, POD and CAT in leaves induced by the damage of A. lucorum and artificial needling were significantly higher than the leaves without damage, and the activities of SOD and CAT induced by A. lucorum damage were significantly higher than the artificial needling. There was not significant difference among the SOD activities in buds without damage, and those damaged by A. lucorum and artificial needling, while POD activities were significantly increased with the damage of A. lucorum and artificial needling. CAT activity in buds induced by A. lucorum damage was significantly higher than needling ones. At the flowering stage, SOD and CAT activities had no significant difference while POD was significantly increased with the damage stress, and that induced by A. lucorum damage was significantly higher than needling ones. At the young fruiting stage, the POD activities which were induced by A. lucorum damage and artificial needling were significantly higher than those without damage. At the same time, SOD activity was significantly higher in A. lucorum damaged fruit, while CAT activity was statistically indifferent. These results indicated that the defense enzymes in the tissues of winter jujube varied at the damage stress. Stress defense enzyme activities of winter jujube differed to varied damage levels of A. lucorum. With increasing damage, SOD activities in leaves and flowers increased initially and then decreased, while the activities of POD and CAT increased. With the increase of damage level, SOD activity in buds was statistically indifferent, while that of POD and CAT increased significantly. With the increasing damage, SOD activity of young fruits decreased initially, and then increased, however, that of POD increased initially and then decreased. 【Conclusion】The damage of A. lucorum could induce a series of biochemical reactions in host-plants. The activities of SOD, CAT and POD in leaves and the activity of POD in the reproductive organs (buds, flowers and fruits) were much higher under the damage stress. Both physical and chemical damages of A. lucorum induced more defense enzymes than the artificial needling. Defense enzymes in different tissues of winter jujube showed variations with the increasing levels of damage.