英文文献小短文(原文加汉语翻译)

A fern that hyperaccumulates arsenic(这是题目，百度一下就能找到原文好，原文还有表格，我没有翻译) A hardy, versatile, fast-growing plant helps to remove arsenic from contaminated soilsContamination of soils with arsenic,which is both toxic and carcinogenic,is widespread1. We have discovered that the fern Pteris vittata (brake fern) is extremely efficient in extracting arsenic from soils and translocating it into its above-ground biomass. This plant which, to our knowledge, is the first known arsenic hyperaccumulator as well as the first fern found to function as a hyperaccumulator has many attributes that recommend it for use in the remediation of arsenic-contaminated soils.We found brake fern growing on a site in Central Florida contaminated with chromated copper arsenate (Fig. 1a). We analysed the fronds of plants growing at the site for total arsenic by graphite furnace atomic absorption spectroscopy. Of 14 plant species studied, only brake fern contained large amounts of arsenic (As;3,2804,980 p.p.m.). We collected additional samples of the plant and soil from the contaminated site (18.81,603 p.p.m. As) and from an uncontaminated site (0.477.56 p.p.m. As). Brake fern extracted arsenic efficiently from these soils into its fronds: plants growing in the contaminated site contained 1,4427,526 p.p.m. Arsenic and those from the uncontaminated site contained 11.864.0 p.p.m. These values are much higher than those typical for plants growing in normal soil, which contain less than 3.6 p.p.m. of arsenic3. As well as being tolerant of soils containing as much as 1,500 p.p.m. arsenic, brake fern can take up large amounts of arsenic into its fronds in a short time (Table 1). Arsenic concentration in fern fronds growing in soil spiked with 1,500 p.p.m. Arsenic increased from 29.4 to 15,861 p.p.m. in two weeks. Furthermore, in the same period, ferns growing in soil containing just 6 p.p.m. arsenic accumulated 755 p.p.m. Of arsenic in their fronds, a 126-fold enrichment. Arsenic concentrations in brake fernroots were less than 303 p.p.m., whereas those in the fronds reached 7,234 p.p.m.Addition of 100 p.p.m. Arsenic significantly stimulated fern growth, resulting in a 40% increase in biomass compared with the control (data not shown).After 20 weeks of growth, the plant was extracted using a solution of 1:1methanol:water to speciate arsenic with high-performance liquid chromatographyinductively coupled plasma mass spectrometry. Almost all arsenic was present as relatively toxic inorganic forms, with little detectable organoarsenic species4. The concentration of As(III) was greater in the fronds (4780%) than in the roots (8.3%), indicating that As(V) was converted to As(III) during translocation from roots to fronds.As well as removing arsenic from soils containing different concentrations of arsenic (Table 1), brake fern also removed arsenic from soils containing different arsenic species (Fig. 1c). Again, up to 93% ofthe arsenic was concentrated in the fronds. Although both FeAsO4 and AlAsO4 are relatively insoluble in soils1, brake fern hyperaccumulatedarsenic derived from these compounds into its fronds (136315 p.p.m.)at levels 36 times greater than soil arsenic.Brake fern is mesophytic and is widely cultivated and naturalized in many areas with a mild climate. In the United States, it grows in the southeast and in southern California5. The fern is versatile and hardy, and prefers sunny (unusual for a fern) and alkaline environments (where arsenic is more available). It has considerable biomass, and is fast growing, easy to propagate,and perennial.We believe this is the first report of significant arsenic hyperaccumulation by an unmanipulated plant. Brake fern has great potential to remediate arsenic-contaminated soils cheaply and could also aid studies of arsenic uptake, translocation, speciation, distribution and detoxification in plants.*Soil and Water Science Department, University ofFlorida, Gainesville, Florida 32611-0290, USAe-mail: Cooperative Extension Service, University ofGeorgia, Terrell County, PO Box 271, Dawson,Georgia 31742, USADepartment of Chemistry & SoutheastEnvironmental Research Center, FloridaInternational University, Miami, Florida 33199,1. Nriagu, J. O. (ed.) Arsenic in the Environment Part 1: Cyclingand Characterization (Wiley, New York, 1994).2. Brooks, R. R. (ed.) Plants that Hyperaccumulate Heavy Metals(Cambridge Univ. Press, 1998).3. Kabata-Pendias, A. & Pendias, H. in Trace Elements in Soils andPlants 203209 (CRC, Boca Raton, 1991).4. Koch, I., Wang, L., Ollson, C. A., Cullen, W. R. & Reimer, K. J.Envir. Sci. Technol. 34, 2226 (2000).5. Jones, D. L. Encyclopaedia of Ferns (Lothian, Melbourne, 1987).积累砷的蕨类植物 耐寒，多功能，生长快速的植物，有助于从污染土壤去除砷 有毒和致癌的土壤砷污染是非常广泛的。我们已经发现，蕨类植物蜈蚣草（凤尾蕨）对从土壤中提取砷和转运到地上部生物量是非常有效的。据我们所知这种植物，是第一个已知的砷超富集植物以及也是第一种在已发现的蕨类中可以作为超富集植物，它有许多属性比如建议使用在砷污染土壤的修复。 我们发现被铬砷酸铜污染的生长在佛罗里达州中部的一个站点的凤尾蕨图1a）。我们用石墨炉原子吸收法分析了在站点正生长植物叶子总砷的吸收光谱。对于14种研究植物物种中，只有凤尾蕨植物中含有大量的砷（含量；32804980 ppm）。我们从受污染的站点（18.81603 ppm）和未受污染的站点（0.477.56 ppm）收集更多的植物和土壤样品。凤尾蕨从土壤中有效吸收砷转运到其叶子中，在受污染的站点生长的植物，含有14427526 ppm的砷和那些未受污染的站点包含11.864 ppm的这些值是比那些正常的土壤中生长的植物的高很多，其中包含小于3.6 ppm的砷。对于含有高达1500 ppm砷的疏松土壤中，凤尾蕨植物可以在很短的时间内吸收大量的砷进入它的叶子（表1）。在掺入1500 ppm砷的土壤中蕨类叶子中砷浓度是不断增长的，在两周内砷含量从29.4增加到15861 ppm。在蕨类叶子中的砷，是126倍的富集。凤尾蕨根的砷浓度小于303 ppm，而那些在叶的浓度达到7234 ppm。 加入100 ppm的砷显著刺激蕨类生长，导致在与对照相比，生物量增加了（数据未显示）。 经过20周的增长，用1:1甲醇：水的方法提取该植物用高效液相色谱法电感耦合等离子体质谱法来平衡砷。目前几乎所有的砷是相对无毒的无机形式，几乎没有检测到有机砷物种。作为（）的浓度叶（47-80）与根（8.3）相比更多，表示AS（V）被转换AS(III）在根转运到叶的过程中。 以及从土壤中除去砷的植物含有不同浓度的砷（表1），从土壤中去除含砷的凤尾蕨也含有不同形态的砷（图1C）。再着，高达93%的砷主要集中在叶。虽然feaso4和AlAsO42H2O在土壤中的相对不溶，凤尾蕨富集的砷来自这些化合物进入它的叶状体（136315 ppm）在3级6倍大于土壤砷。凤尾蕨是裸子植物，并广泛栽培归功于许多地区气候温和。在美国，它生长在东南部和加利福尼亚南部。蕨类植物是有多种有优点，耐寒，喜欢阳光（不寻常的蕨类植物）和碱性环境（如砷是更有效）。它具有相当大的生物量，而且常年生长迅速，易于繁殖。 我们相信这是用一个未经处理的显著砷超富集植物为例的第一次报告。凤尾蕨在修复砷污染土壤方面的潜力很大，也可以帮助研究砷的吸收，转运，形态研究，在植物中的分布及排毒。*土壤和水科学系，大学Florida, Gainesville, Florida 32611-0290, USA佛罗里达州，盖恩斯维尔，佛罗里达州32611-0290，美国e-mail: 电子邮件：Cooperative Extension Service, University of合作推广服务，大学Georgia, Terrell County, PO Box 271, Dawson,格鲁吉亚，特勒尔县，邮政信箱271，道森，Georgia 31742, USA佐治亚州31742，美国Department of Chemistry & Southeast化学与东南部Environmental Research Center, Florida环境研究中心，佛罗里达州International University, Miami, Florida 33199,国际大学，迈阿密，佛罗里达州，33199，1。Nriagu，J. O.（主编）环境中的砷1部分：循环and Characterization (Wiley, New York, 1994).与特性（威利，纽约，1994）。2. Brooks, R. R. (ed.) Plants that Hyperaccumulate Heavy Metals2。布鲁克斯，R. R.（主编），重金属超富集植物(Cambridge Univ. Press, 1998).（剑桥大学出版社，1998）。3. Kabata-Pendias, A. & Pendias, H. in Trace Elements in Soils and3。kabata pendias，A. pendias，在土壤中的微量元素Plants 203209 (CRC, Boca Raton, 1991).植物203209（CRC，博卡拉顿，1991）。4. Koch, I., Wang, L., Ollson, C. A., Cullen, W. R. & Reimer, K. J.4。科赫，I.，王，L.，ollson，C. A.，卡伦，W. R. & Reimer，K. J.Envir. Sci. Technol. 34, 2226 (2000).环境。SCI。技术。34，22，26（2000）。5. J