镉胁迫对龙葵幼苗氮代谢及其相关酶活性的影响  

Effect of cadmium on nitrogen metabolism and relative enzymes activity in Solanum nigrum L seedlings

作　　者：郭智[1,2] 原海燕[3] 陈留根[1] 奥岩松[2] 

机构地区：[1]江苏省农业科学院农业资源与环境研究所,江苏南京210014 [2]上海交通大学农业与生物学院植物科学系,上海200240 [3]江苏省中国科学院植物研究所(南京中山植物园),江苏南京210014

出　　处：《生态环境学报》2010年第5期1087-1091,共5页Ecology and Environmental Sciences

基　　金：上海市科学技术委员会科技攻关计划(07DZ19604)

摘　　要：采用营养液培养方法,研究了系列镉浓度处理对龙葵(Solanum nigrumL)幼苗氮代谢的影响。结果表明:龙葵根系可溶性蛋白质较叶片受Cd影响更大。龙葵植株叶片和根系NO3--N含量、硝酸还原酶(NR)、谷氨酰胺合成酶(GS)活性均随镉浓度提高而先增后降,且随处理时间的延长而逐渐下降。叶片NO3--N含量和NR活性均在25μm镉处理8d后达到峰值,而根系NO3--N则在50μm镉处理8d后最高。叶片NO3--N含量受镉处理影响较根系稍大。然而,龙葵叶片中NH4+-N含量随镉浓度升高和时间延长逐渐升高,100μm镉处理16d后最高,表明镉胁迫下龙葵叶片铵态氮富集效应明显。龙葵叶片和根系中谷氨酸脱氢酶(GDH)活性随镉处理浓度提高和处理时间延长而逐渐升高,100μm镉处理16d后达到峰值。Nitrogen metabolism in Solanum nigrum L seedlings under cadmium（Cd）stress was investigated by nutrient solution culture method.The results showed that NO3--N and soluble protein contents,NR and GS activities in the leaves and roots increased firstly and decreased with increasing Cd concentration in the solutions,and decreased along with treatment time.And,soluble protein contents in the roots decreased with more extent.After 8 d of Cd exposure（25μm）,NO3--N contents and NR activities in the leaves of S.nigrum reached peak values,but root NO3--N contents reached maximum after 8 d of 50μm Cd exposure,and leaf NO3--N were more sensitive to root.However,NH4 ＋-N contents in the leaves of S.nigrum increased with increasing Cd concentration and along with treatment time,and reached maximum after 16 d of 100μm Cd exposure,which suggested significant NH4 ＋-N accumulation in the leaves of S.nigrum subjected to Cd stress.Furthermore,GDH activities in the leaves and roots increased with increasing Cd concentration and along with exposure time,and reached peak values after 16 d of 100μm Cd exposure.

关 键 词：龙葵(Solanum nigrumL) 镉 氮代谢 

分 类 号：X171.5[环境科学与工程—环境科学]