State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210093, China.
Ecotoxicol Environ Saf. 2011 Jan;74(1):41-7. doi: 10.1016/j.ecoenv.2009.02.009. Epub 2010 Oct 8.
Oxidative stress and biochemical responses of spinach seedlings to soil Pb stress were investigated by pot experiments. The seedlings were exposed to 0-500 mg kg(-1) extraneous Pb. After 30 days of germination, production of O(2)(-), HSP 70, HSP 60, superoxide dismutase (SOD) activities, carbonyl groups and lipid peroxidation was significantly induced by soil Pb. After 50 days, HSP 70 and HSP 60 decreased, and HSP 60 was significantly inhibited at 500 mg kg(-1). The results indicated that Pb probably induced oxidative stress and proteotoxicity to the seedlings through O(2)(-) accumulation, and that SOD, HSP 70 and HSP 60 were important defense mechanisms to alleviate the oxidative stress. It is found that O(2)(-), HSP 70 and HSP 60 were the most sensitive parameters and had the potential to act as biomarkers for early warning of soil Pb contamination. Concentrations of soil Pb, exposing time and combination of multiple parameters should be also taken into consideration when assessing soil Pb pollution by these biomarkers.
采用盆栽试验研究了土壤 Pb 胁迫对菠菜幼苗的氧化应激和生化响应。将幼苗暴露于 0-500mg/kg 的外源 Pb 中。在发芽 30 天后，土壤 Pb 显著诱导了 O(2)(-)、HSP 70、HSP 60、超氧化物歧化酶（SOD）活性、羰基和脂质过氧化的产生。50 天后，HSP 70 和 HSP 60 下降，500mg/kg 时 HSP 60 显著受到抑制。结果表明，Pb 可能通过 O(2)(-)积累诱导幼苗发生氧化应激和蛋白毒性，SOD、HSP 70 和 HSP 60 是缓解氧化应激的重要防御机制。研究发现，O(2)(-)、HSP 70 和 HSP 60 是最敏感的参数，有潜力作为土壤 Pb 污染的早期预警生物标志物。在利用这些生物标志物评估土壤 Pb 污染时，还应考虑土壤 Pb 浓度、暴露时间和多个参数的组合。
