【摘要】 在温室模拟增强紫外辐射UV-B(280~320nm)环境下,研究镧(La)对UV-B胁迫下大豆幼苗叶片硝酸还原酶活性(N itrate reductase activity,NRA)、可溶性蛋白、淀粉和可溶性糖含量的影响。结果显示,高低两个紫外强度剂量下,叶片NRA较对照组都有显著下降,处理5d后降幅分别达到40.9%和42.0%;而经过适宜浓度LaC l3(20mg/L)预处理后,降幅较UV-B单独处理组均有明显升高,分别为39.2%和38.9%。蛋白质、淀粉和可溶性糖含量变化与NRA相似,但是紫外辐射处理组蛋白含量变化较对照组呈现先升高后下降趋势。结果表明适宜浓度的La3+能够促进NRA以及UV-B胁迫下NRA活性的提高,缓解UV-B胁迫对植物的伤害。更多还原

【Abstract】 Effect of La³⁺ on the leaf nitrate reductase activity（NRA） and the contents of soluble protein,soluble sugar and starch in soybean seedlings were studied under elevated ultraviolet-B radiation（UV-B,280³20nm）.The result showed that NRA decreased significantly under the two different doses of UV-B treatment,with a decrease of 40.9% and 42.0% compared to the control after 5 days of treatment.But after pretreated with 20mg/L LaCl₃,the NRA increased by 5%¹0% compared to that treated by UV-B radiation only.The same changes were found with contents of starch and soluble sugar as NRA.But protein content only had a little difference,which increased after UV-B treatment in the beginning 3 days and decreased in following 2 days.Our results indicated that 20mg/L LaCl₃ had an effect to increase leaf NRA treated by UV-B,and alleviated seedling damage caused by UV-B.更多还原