摘要：试验采用沙基培养的方法研究了硝酸镧浸种与土施亚硒酸钠处理对高浓度铜盐胁迫下济麦22、山农28幼苗叶片SOD、POD活性以及可溶性蛋白含量的影响。结果表明，100 mg/L硫酸铜处理降低了小麦叶片SOD和POD活性、使可溶性蛋白含量升高，对小麦幼苗造成了毒害。镧浸种缓解济麦22和山农28铜胁迫条件下幼苗抗氧化酶活性抑制的最适浓度范围分别为30～50 mg/L和30～100 mg/L；土施亚硒酸钠缓解二者抗氧化酶活性的最适浓度范围分别为15～25 mg/L和5～25 mg/L；镧浸种和亚硒酸钠复合处理缓解二者抗氧化酶活性的适宜浓度分别为100 mg/L镧浸种+5～25 mg/L亚硒酸钠和50 mg/L镧浸种+5～25 mg/L亚硒酸钠。兩品种小麦对镧浸种及土施亚硒酸钠溶液浓度的敏感性存在差异，山农28抗氧化酶系统抵抗高浓度铜盐胁迫的能力强于济麦22。镧浸种和亚硒酸钠处理对于高浓度铜盐胁迫幼苗的单独效应及二者的复合效应，均对两品种小麦的SOD、POD活性产生了“低促高抑”的影响，镧浸种处理提高了小麦幼苗对亚硒酸钠的耐受能力，并且二者的复合作用对增强SOD及POD活性具有互补性。试验统计结果表明，镧和硒可能并不通过促进SOD酶合成基因表达，而是通过改变构象或以进行化学修饰的方式提高活性，剂量的影响遵循Hormesis效应的变化规律。适当浓度的镧浸种和土施亚硒酸钠的复合处理能有效缓解铜胁迫对小麦幼苗的氧化伤害。
关键词：小麦；镧；硒；铜胁迫；抗氧化酶；可溶性蛋白
中图分类号：S512.1+1文献标识号：A文章编号：1001-4942（2018）04-0064-09
Abstract The effects of seed soaking with lanthanum nitrate and watering sodium selenite on the SOD and POD activities and soluble protein content in Jimai 22 and Shannong 28 seedling leaves under copper stress were investigated using the sandculture method. The results showed that 100 mg/L copper sulfate treatment reduced the activities of SOD and POD and increased the content of soluble protein in wheat leaves， which poisoned wheat seedlings. For relieving the inhibition to antioxidase activity in Jimai 22 and Shannong 28 under copper stress， the optimum soaking concentration of lanthanum nitrate were 30～50 mg/L and 30～100 mg/L， and the optimum watering concentration of sodium selenite were 15～25 mg/L and 5～25 mg/L， and the optimum compound treatment conditions were 100 mg/L lanthanum with 5 ～ 25 mg/L sodium selenite and 50 mg/L lanthanum with 5～25 mg/L sodium selenite， respectively. The sensitivity of the two wheat variety to lanthanum soaking and watering sodium selenite solution was different. Shannong 28 had better antioxidase system to resist high concentration copper stress. The single and compound effects of lanthanum seed soaking and watering sodium selenite on the SOD and POD activities of the two wheat variety seedlings under the high concentration of copper stress showed promoting at low concentration and inhibiting at high concentration. Lanthanum soaking treatment improved the tolerance of wheat seedlings to sodium selenite，and their compound effects were complementary on enhancing the SOD and POD activities. These results indicated that lanthanum and selenium might increase the activity by not promoting the expression of SOD synthase genes， but by conformation changing or chemical modification， and the effects of dose followed the Hormesis effect. We concluded that soaking seeds with lanthanum and watering sodium selenite solution at optimum concentration could effectively relieve the oxidative damage to wheat seedlings under copper stress.