La对UV - B辐射下大豆幼苗 NRA和可溶性蛋白的影响

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(Nitrate 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 LaCl3 (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。

Effect of La3+ on soybean seedling nitrate reductase activity and soluble protein content under supplemental UV-B radiation

Effect of La~(3 ) 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,280~320nm).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 LaCl_3,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 LaCl_3 had an effect to increase leaf NRA treated by UV-B,and alleviated seedling damage caused by UV-B.