铅对八楞海棠氮素代谢的影响

目的]丰富果树铅胁迫的理论研究,为果树铅污染的预测预报、综合治理提供理论依据。方法]以去离子水为对照,研究500、1000、2000mg/k(g以Pb2+计)的铅胁迫对八楞海棠氮素代谢的影响。结果]八楞海棠的硝酸还原酶活性在500mg/kg的铅胁迫下达到最高值,2000mg/kg的铅胁迫使其活性降至对照的81%。铅胁迫对八楞海棠叶片脯氨酸含量的影响不大。八楞海棠的可溶性蛋白含量随着铅胁迫时间的延长和铅胁迫浓度的增加而下降,500、1000、2000mg/kg铅胁迫21d时,其含量分别降至对照的83.2%、75.6%和67.9%。结论]高浓度的铅胁迫使八楞海棠的硝酸还原酶活性和可溶性蛋白含量下降。

Effects of Pb Stress on the Nitrogen Metabolism of Malus robusta

Objective] The research aimed to enrich the theoretical research on Pb stress of fruit trees and provide the theoretical basis for the forecast and comprehensive treatment of Pb pollution to fruit trees. Method] With deionized water as CK, the effects of Pb stress with different concn. of 500, 1 000 and 2 000 mg/kg Pb2 on the nitrogen metabolism of Malus robusta were studied. Result] The activity of nitrate reductase reached the maximum under Pb stress at 500 mg/kg and that was decreased to 81% of CK under Pb stress at 2 000 mg/kg. Pb stress had smaller effects on the content of praline in the leaves of M. robusta. The content of soluble protein was decreased with the prolonging of Pb stress time and the increasing of Pb stress concn.and that were decreased to 83.2%,75.6% and 67.9% of CK resp. under Pb stress at 500,1 000 and 2 000 mg/kg for 21 days. Conclusion] The activity of nitrate reductase and the content of soluble protein was decreased by Pb stress at high concn.