铵态氮胁迫下金鱼藻的过氧化损伤和抗氧化能力  

NH_4^+-N Stress on Peroxidation Damage and Antioxidative Capability of Ceratophyllum demersum

作　　者：高镜清[1,2] 黄五星[2] 黄宇[2] 熊治廷[2] 

机构地区：[1]郑州大学化学系/环境科学研究院,河南郑州450001 [2]武汉大学资源与环境学院,湖北武汉430079

出　　处：《武汉大学学报（理学版）》2010年第5期590-596,共7页Journal of Wuhan University:Natural Science Edition

基　　金：国家重点基础研究发展计划(973)项目(2002CB412300)

摘　　要：本实验通过控制pH值(7和9)以区分分子态氨(NH3)和离子态氨(NH4+),研究了不同浓度铵态氮(NH4+-N)对金鱼藻过氧化损伤和抗氧化能力的影响.研究表明,随着水体铵态氮浓度的增加,金鱼藻组织内叶绿素含量下降.在中性pH铵态氮胁迫下,金鱼藻组织内过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性、还原型谷胱甘肽(GSH)含量升高,但是在高pH铵态氮胁迫下,金鱼藻组织内SOD活性、POD活性、GSH含量下降.而过氧化氢酶(CAT)活性、抗坏血酸(ASA)和丙二醛(MDA)含量在两个pH环境中随铵态氮处理浓度的增加而不断升高.在pH9的条件下,高浓度铵态氮对金鱼藻的生长胁迫尤其明显.结果说明水体铵态氮浓度的升高对金鱼藻具有毒害作用,而且随水体pH升高,植物生理响应越明显.In this experiment,we carefully used controlled pH ranges（7and 9）to distinguish the effect of the un-ionised NH3from that of the NH4＋ion.The objective was to find the effect of total ammonia nitrogen concentration and pH on peroxidation damage and antioxidative capability of Ceratophyllum demersum.The results show that clear effect of ammonia addition was to decrease chlorophyll（a＋b）content and inhibit photosynthesis.As a result,these decreased relative growth rates of C.demersum.These ammonia additions decreased Chlorophyll contents of C.demersum.Peroxidase（POD）,superoxide dismutase（SOD）activities and glutathione（GSH）contents significantly increased at pH 7and were inhibited at pH 9under high ammonia condition,while the activities of two enzymes and GSH contents didn＇t increase until pH 9under high ammonia condition.Catalase（CAT）activity,ascorbic acid（ASA）and malondialdehyde（MDA）contents significantly increased under all ammonia conditions.C.demersum was stressed above pH 9under high ammonia conditions.It is suggested that NH4＋-N has toxic effects on C.demersum,and the higher the pH in water is,the more obvious the physiological responses of C.demersumexhibites.

关 键 词：铵态氮 金鱼藻 胁迫 过氧化损伤 抗氧化性保护酶 

分 类 号：Q948.8[生物学—植物学]