Lead bioaccumulation potential of an aquatic macrophyte Najas indica are related to antioxidant system.
Lead bioaccumulation potential of an aquatic macrophyte Najas indica are related to antioxidant system.
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DOI：
10.1016/j.biortech.2009.12.031
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发表时间：
2010-05
影响因子：
11.4
通讯作者：
Ragini Singh;R. D. Tripathi;S. Dwivedi;Amit Kumar;P. Trivedi;D. Chakrabarty
中科院分区：
文献类型：
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作者：
Ragini Singh;R. D. Tripathi;S. Dwivedi;Amit Kumar;P. Trivedi;D. Chakrabarty
不同浓度的硝酸铅胁迫下，水仙植株对铅的生物积累量显著增加(3554μgg−1DW)，并导致丙二醛、电导率和过氧化氢含量增加。在GSH、半胱氨酸、抗坏血酸、脯氨酸等多种分子抗氧化剂的诱导下，超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(GPX)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)等抗氧化酶活性也随之升高。此外，铅暴露的植株表现出显著的半胱氨酸合成酶和谷胱甘肽-S转移酶的活性。在4d后50μM出现明显的毒害症状，表现为叶片黄化和碎裂，并伴有粘液分泌物。生物积累的铅似乎是通过激活抗氧化系统和硫醇途径有效地被Najas植物耐受的，这一点从生物量增加到10μM-Pb.由此可见，这些植物具有较高的耐金属性和较高的浓缩系数，可用于高污染水体的植物修复。
Plants of Najas indica bioaccumulated significantly higher amounts of Pb (3554μgg−1dw) when, exposed to varying concentrations of Pb(NO3)2.This also led to increased malondialdehyde (MDA), electrical conductivity (EC) and H2O2content. In response to this, the activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR) were elevated along with the induction of various molecular antioxidants including GSH, cysteine, ascorbic acid and proline. Further, Pb exposed plants showed significantly increased cysteine synthase and glutathione-S-transferase activity. Visible symptoms of toxicity were evident at 50μM after 4d showing chlorosis and fragmentation of leaves with mucilaginous discharge. It seems that bioaccumulated Pb is efficiently tolerated by Najas plants through activation of antioxidant system and thiolic pathways which was evident by the increased biomass up to 10μM Pb. Therefore, it appears that due to metal tolerance characteristics with high concentration factor these plants can find use in phytoremediation of aquatic system highly contaminated by Pb.