Hg2+ 与POD 复合处理对小麦萌发及幼苗生长的影响.pdf

植物学通报?2004, 21 (5): 531?538 Chinese Bulletin of Botany 研究论文 Hg2+ 与 POD 复合处理对小麦萌发 及幼苗生长的影响 ?? 马剑敏?? 李?今?? 张改娜?? 杨柯金?? 王?琳?? 吴振斌① 1(中国科学院水生生物研究所 武汉 430072) 2((河南师范大学生命科学学院 新乡 453002) 摘要 通过水培实验研究了0、10、20、50、70和100 mg.L?1 Hg2+和65 U.mL?1的过氧化物酶(POD)混 合浸种对小麦(Triticum aestivum L.)萌发及幼苗生长过程中的10个形态和生理生化指标的影响。结果表 明：施加外源POD可明显提高种子发芽率、植株日均增重和幼苗叶片的可溶性蛋白含量，增加幼苗叶 片内源超氧物歧化酶(SOD)和POD的活性，拮抗Hg2+胁迫对种子发芽率、苗高、日均增重及叶片可溶性 蛋白含量的不利影响，Hg2+浓度较高时(≥ 50 mg.L?1)，对种子发芽率和日均增重的拮抗作用更明显，并 对较低浓度Hg2+(≤ 20 mg.L?1)胁迫引起的叶片SOD活性的上升和低于100 mg.L?1的 Hg2+胁迫引起的叶片 POD活性的上升有进一步的促进作用；然而对幼苗平均最长根长度、侧根数和幼苗叶片叶绿素含量则 无明显影响。 关键词 Hg2++ POD，小麦萌发，SOD，POD Effects of POD and Hg2+ on Seed Germination and Seedling Growth of Wheat 1,2MA Jian-Min 1LI Jin 2ZHANG Gai-Na 2YANG Ke-Jin 2WANG Lin 1WU Zhen-Bin① 1(Hydrobiology Institute, the Chinese Academy of Sciences, Wuhan 430072) 2(College of Life Science, Henan Normal University, Xinxiang 453002) Abstract Experiments were carried out to study the effects of soaking wheat seeds with POD (peroxidase) and Hg2+ together on 10 morphological and physiological indexes during the seed germination and seedling growth. The results showed that exogenous POD could raise the seed germination rate, wake the increased average weight per day and the soluble protein centent of the leaves, and enhance the activities of SOD (superoxide dismutase) and POD of the leaves. The exog- enous POD also resist and weaken the effects of the Hg2+ stress on the seeds germination rate, height of wheat, increased average weight per day and the soluble protein. Moreover, when Hg2+≥ 50 mg. L?1, the resisting and weakening effects on the germination rate and the increased average fresh weight per day were more obvious. Besides, exogenous POD could further heighten the activities of SOD under the