Before now most of the research has concentrated on the action of single compounds against organisms . when two or more chemicals are applied simultaneously to a living system or unit , the combined effect may be one of the followings : additive action , antagonism and synergism 目前，有关污染物的生物效应研究多数还是集中在单个化合物的生物效应，随着多种污染物(包括重金属)进入水域环境后，所发生的联合毒性效应往往表现为相加、拮抗或增毒作用。
In the field of the phytoremediation of copper pollution , submerged macrophytes are focused less than the terrestrial plants . in this study , ceratophyllum demersum l . and cahomba caroliniana a . gray were used as the test plant . the following two aspects were investigated in vivo methods : 1 ) the toxicity effects of cu2 + on the three main antioxidant enzymes ( including cat , pod and sod ) of two submerged macrophytes were detected at different low doses and on the chronic exposure , in order to establish the dose - effect relationship and the time - effect relationship , and thereby acquire the toxicity threshold ; and 2 ) with two submerge macrophytes throng cultured individual or combined on the chronic exposure , it was found on the bcf of copper and the influence of interspecific relationships to the submerge macrophytes resistance or bioconcentration 本论文以两种大型沉水植物金鱼藻( c . demersuml . )和水盾草( c . carolinianaa . )为受试植物，从它们对水体中cu ~ ( 2 + )的生物富集作用和动态，以及cu ~ ( 2 + )对它们体内抗氧化酶的急性毒性效应和亚急性毒性效应两方面进行了研究： 1 )通过体内暴露不同剂量的cu ~ ( 2 + ) ，探讨cu ~ ( 2 + )对植物体内三种主要的抗氧化物酶( sod ， pod ， cat )的毒理效应，建立剂量?效应关系和时间?效应关系，以揭示沉水植物对cu ~ ( 2 + )的抗性机制； 2 )通过对金鱼藻，水盾草单独培养和共同培养的方式，分别研究了两种沉水植物对cu ~ ( 2 + )的生物富集系数及其动态以及两种植物的种间关系对富集铜和植物耐性的影响，综合评价了两种植物在铜污染水体的植物修复中的应用前景。
