Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Sci Total Environ. 2013 Jan 1;442:143-51. doi: 10.1016/j.scitotenv.2012.10.056. Epub 2012 Nov 22.
Arsenic (As) contamination poses a high risk to human health. Phytoremediation based on As hyperaccumulator Pteris vittata has been utilized on large areas of contaminated farmland in southern China. However, the reason for the observed differences in As removal among P. vittata populations remains unclear. In this study, spores of four P. vittata populations were collected from four neighboring sites with varying soil As concentration (from 108 mg·kg(-1) to 7527 mg·kg(-1)) and then cultured in a controlled environment to analyze their differing abilities in terms of As accumulation and tolerance. The results indicate that populations from low-As habitats exhibited 80% greater shoot As concentrations compared with those from high-As habitats. On the other hand, populations from high-As habitats exhibited approximately five times greater biomass compared with those from low-As habitats when exposed to the same As stress. Thus, the As accumulation and tolerance of P. vittata were suggested to be two independent processes. Further investigations reveal that the As absorption and As species conversion occurring in roots are two essential activities that bridge the soil As concentration and the responses of P. vittata to As. Depending on the As concentration of the target soil, the selection of different P. vittata populations can result in approximately an eight-fold difference in terms of remediation efficiency.
砷（As）污染对人类健康构成了高风险。基于砷超积累植物蜈蚣草的植物修复已在中国南方的大面积受污染农田上得到应用。然而，对于观察到的蜈蚣草种群在砷去除方面的差异的原因仍不清楚。在这项研究中，从四个土壤砷浓度（从 108 毫克/千克到 7527 毫克/千克）不同的相邻地点采集了四个蜈蚣草种群的孢子，并在受控环境中进行培养，以分析它们在砷积累和耐受方面的不同能力。结果表明，来自低砷生境的种群的茎部砷浓度比来自高砷生境的种群高 80%。另一方面，当暴露在相同的砷胁迫下时，来自高砷生境的种群的生物量比来自低砷生境的种群大约高出五倍。因此，蜈蚣草的砷积累和耐受被认为是两个独立的过程。进一步的研究表明，根中发生的砷吸收和砷形态转化是连接土壤砷浓度和蜈蚣草对砷的响应的两个重要活动。根据目标土壤的砷浓度，选择不同的蜈蚣草种群可以使修复效率相差约八倍。
