四氯乙烯污染对大豆幼苗抗氧化特征的影响

通过室内模拟试验,研究了不同浓度四氯乙烯(PCE)污染对大豆幼苗抗氧化特性的影响。结果表明:随PCE胁迫强度的增加,大豆幼苗的丙二醛(MDA)、超氧阴离子(O2.-)、脯氨酸及谷胱甘肽(GSH)含量均呈累积升高的趋势,且均存在显著的剂量-效应关系。与对照组相比,当浓度达到0.30 mg.kg-1时,大豆幼苗体内脯氨酸及GSH含量明显累积;浓度达到30.00 mg.kg-1时,O2.-及MDA含量明显升高,幼苗膜脂过氧化显著;低浓度PCE胁迫会激活SOD与CAT酶的活性,当浓度超过0.30 mg.kg-1时则随浓度的升高而降低。

Cu^2+、Zn^2+胁迫对粉黛乱子草种子萌发及抗氧化特征影响

探究粉黛乱子草在不同质量浓度的铜溶液、锌溶液和铜锌复合溶液胁迫下,对种子萌发特性和抗氧特征的影响.结果表明,在3种胁迫处理下,粉黛乱子草的发芽率、发芽势和发芽指数呈先增后减的趋势;活力指数、胚苗长、胚根长和幼苗鲜重随处理溶液质量浓度的升高呈逐级递减的趋势,胚根长受到的抑制作用显著大于胚苗长.Cu^2+(≥100 mg·L^-1)、Zn^2+(≥200 mg·L^-1)、Cu^2++Zn^2+[≥(200 mg·L^-1+200 mg·L^-1)]胁迫对粉黛乱子草种子萌发及幼苗生长具有显著的抑制作用(P<0.05).粉黛乱子草叶片中的丙二醛含量与处理溶液质量浓度呈正比;随着3种胁迫处理溶液质量浓度的增高,过氧化氢酶、过氧化物酶和超氧化物歧化酶活性呈先增后减的趋势.粉黛乱子草抗氧化酶系统在Cu^2+、Zn^2+及Cu2++Zn2+胁迫下响应机制不同,对不同重金属的抗性能力存在差异.通过隶属函数法进行综合评析,粉黛乱子草对3种重金属胁迫的耐受性强弱依次为Zn^2+>Cu^2++Zn^2+>Cu^2+.

Manila clam Venerupis philippinarum as a biomonitor to metal pollution

The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the Bohai Sea; however, little attention has been paid to potential biological differences between these two pedigrees. In this study, we tested the sensitivity of both pedigrees to marine metal (cadmium and zinc) pollution biomonitoring and marine environmental toxicology. Results demonstrate significant biological differences in gills of white and zebra clams based on metabolic profiles and antioxidant enzyme activities. In addition, we found that hypotaurine, malonate and homarine were relatively high in white clam gills, while alanine, arginine, glutamate, succinate, 4-aminobutyrate, taurine and betaine were high in zebra clam gills. Zebra clam gills were also more sensitive to a mixture of Cd and Zn, as shown by antioxidant enzyme activities and metabolic profiles, but white clam gills could accumulate more Zn. Therefore, we suggest that the white pedigree can be used as a biomonitor to marine Zn pollution, whereas the zebra pedigree can be used for toxicology studies on Cd and Zn mixed pollution.