Zn胁迫下菖蒲的耐受机制及富集能力的研究

TOLERANCE MECHANISM AND ACCUMULATION ABILITY OF ACORUSCALAMUS UNDER THE STRESS OF ZN

采用盆栽的方式,研究了菖蒲在ZnSO4·7H2O(分析纯)浓度分别为0.1,0.2,0.5,1.0,2.0,3.0,4.0 g/kg(土壤)胁迫下的耐受机制及其富集作用。结果表明:较低浓度的Zn处理(ZnSO4·7H2O<0.5 g/kg(土壤))提高了菖蒲的光合作用能力,降低了膜脂质过氧化程度。当菖蒲受到重金属Zn胁迫时,超氧化物歧化酶、过氧化物酶首先被激发,过氧化氢酶是生物氧化过程一系列抗氧化酶的终端,其激活有一定的滞后。高浓度的Zn胁迫会超过菖蒲防御反应的阀值(ZnSO4·7H2O=1 g/kg(土壤)),对植株产生毒害作用。菖蒲在低浓度Zn处理条件下(ZnSO4·7H2O<0.2 g/kg(土壤))对Zn的富集能力明显高于高浓度Zn,但转运系数均小于1。菖蒲在较低浓度Zn污染的植物修复中可发挥更大作用。

A series of pot experiments were carried out to study the tolerance mechanism and accumulation ability of Acoruscalamus under the stress of zinc( Zn) when the concentration of ZnSO4·7H2O in the soil was 0.1,0.2,0.5,1.0,2.0,3.0,4.0 g /kg( soil) respectively.Experimental results demonstrated that lower concentrations of Zn(ZnSO4·7H2O < 0.5 g /kg( soil)) strengthened the photosynthetic capacity of Acoruscalamus,and the membrane lipoids peroxidation process was slowed down.Also the results indicated that superoxide dismutase and peroxidase were activated before the catalase when Acoruscalamus was under heavy metal Zn stress.Catalase was serveed as the termination of a series of antioxidant enzymes in the biological oxidation process,and its activation had certain hysteresis.High concentrations of Zn would surpass the threshold value(ZnSO4·7H2O = 1 g /kg(soil)) of Acoruscalamus defense reaction,which would hurt the plant.Acoruscalamus showed higher accumulation abilities of Zn under the condition of low concentration of Zn(ZnSO4·7H2O < 0.2 g /kg(soil)) rather than those of high concentration,but the translocation factors were all less than 1.The study demonstrated the Acoruscalamus was more capable of doing phytoremediation of diluted Zn polluted water or soil.