六价铬污染对水车前叶片生理生化及细胞超微结构的影响

以培养在铬 ( VI)浓度梯度的污水中 6 d的水车前为实验材料 ,分析了叶绿素含量和抗氧化酶系统的变化 ,并用透射电镜观察了叶细胞超微结构的损伤。实验结果表明 :( 1 )叶绿素含量在 0 .1 mg/L浓度达到最高 ,而后下降。而可溶性蛋白则一直成下降趋势 ;( 2 ) SOD(超氧化物歧化酶 )、POD(过氧化物酶 )、CAT(过氧化氢酶 )活性影响明显 :三者分别在 0 .1 mg/L、1 0 mg/L、和 1 mg/L处理浓度有抗性峰出现 ,随处理浓度的继续增大则下降 ;( 3)对超微结构造成不可逆损伤 ,特别是对叶绿体、线粒体和细胞核 :叶绿体膨胀 ,被膜破裂和消失 ,叶绿体解体 ;线粒体脊突膨胀和空泡化 ;细胞核变形 ,染色质凝集和核质解体 ,核膜破裂。并根据实验结果初步讨论了重金属对植物的毒害机制

Effects of Cr (VI) on physiological and ultrastructural changes in leaves of Ottelia alismoides (L.) Pers

Ottelia alismoides (L.) Pers was cultivated in water medium polluted with Cr (VI) of different gradient concentration for 6 days. Chlorophyll content and antioxidant enzyme systems changes were analyzed and the ultrastructural damages of leaf cells were observed using electron microscopy. The conclusion showed that: (1)chloropyll content reached the highest point at 0.1 mg/L concentration and decreased afterward, while soluble protein content decreased with the increasing of cultural concentration; (2)Cr (VI) had a bad effect on the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT): they had a resistant peak at 0.1, 10, and 1 mg/L respectively and decreased afterward; (3)Cr (VI) induced non-reversible damage of ultrastructure, especially of the chloroplast,mitochondria and nucleus. That was the swelling of chloroplast, disruption and disappearance of chloroplast membrane, disintegration of chloroplast at last;the swelling of cristae of mitochondria and vacuotation of mitochondria; deforming of nucleus, agglutination of chromatin of nucleus, destruction of nucleoplasm and disruption of nuclear membrane. The toxic mechanism of heavy metals was discussed primarily on the base of experimental consult.