重金属污染土壤植物富集能力的诱导作用研究
|
摘要
近年来，由于土壤重金属污染问题日益突出，有关污染土壤的植物萃取修复技术的基础理论和实际应用正成为研究热点。本文通过植物萃取的盆栽试验、离子树脂交换法、偏剔除试验以及重金属模拟形态试验，研究了施加EDTA、柠檬酸废水、味精废水、木屑真菌腐化物等诱导措施对植株富集土壤中重金属能力及其机理、土壤重金属活性及其各形态的植物可利用性等的影响，得出以下结论：
诱导措施对植株的吸收与转运重金属方面有不同程度的促进作用。EDTA对Cu，Pb的效果较明显；味精废水与木屑真菌腐化物对Zn、Cd的活化效果较好；柠檬酸废水对促进香根草吸收重金属的效果较好，而对高羊茅较弱。EDTA和味精废水对四种重金属在植物体内的运输均有较大的促进作用；柠檬酸废水对Pb在植株体内的运输起抑制作用；除Cd外，柠檬酸废水和淹水处理均使重金属的运输能力增高；真菌腐化物对香根草吸Zn有负面作用，而对其它重金属效果较好。
在外源物质影响下，富阳水稻土根际土壤化学行为异于非根际。诱导措施使富阳水稻土植物根际pH降低，产生“根际酸化”现象，其中以味精废水效果最为明显；在根系和外源物质作用下，根际土壤溶液中重金属含量均高于非根际，外源物质活化程度超过了植物吸收与根际向非根际转移速度之和，其对Cu、Zn的溶出效果顺度为：EDTA＞味精废水＞柠檬酸废水＞木屑真菌腐化物。另外，根际微生物量均高于非根际，不同诱导措施对促进根系分泌的作用不同，其中以味精废水与淹水处理的效果最为明显。根泌物与根际微生物增加提高了根际DOC浓度的增加，但淹水处理降低了根际DOC浓度。
富阳水稻土中重金属的溶解度顺序为Zn＞Pb＞Cu，在有机络合剂作用下，其顺序转变为Zn＞Cu＞Pb；青紫泥中重金属的溶解度顺序为Zn＞Cu＞#b，在有机络合剂作用下，其顺序转变为Cu＞Zn＞Pb。有机络合剂使得土壤溶液中可溶性与离子态重金属的浓度改变，反映了其活性与可利用性较对照不同。
诱导措施与植物根系对土壤重金属的存在形态产生了较大影响。诱导措施对土壤有效态重金属(CaCl_2提取态)的活化程度高于植物吸收与向非根际转移速度之和。以Cu的形态转化为例，诱导措施与根系作用对碳酸盐结合态与有机结合态的活化效果较好，且植物吸收也较强；铁锰氧化物结合态和残渣态使Cu无效化，在EDTA与味精废水作用下，它们可能向可利用性较高的形态转化。
Cu各形态的植物可利用性的顺序为水溶态、交换态、有机结合态＞碳酸盐结合态＞铁锰
氧化物结合态＞残渣态；其中有机结合态最易被植物吸收，而水溶态和交换态最易被植物所
转运。CU各形态受活化俏况oJ植物吸收俏况与有机络合剂的成分与性质有关，EDTA对CU
形态的溶出与促进植物吸收与转运CU素的效果最为明显，味精废水次之。
Recently, phytoextraction theory and application has become a focus in environmental scientific area. In this paper, the plant effect and soil chemical behavior under inducement, including adding EDTA, citric acid waste water, monosodium glutamate waster water and wood fungi contagion was studied by pot experiment, heavy metal activity was evaluated with a cation exchange batch procedure, and the plant availability of heavy metal forms was evaluated with partial dissolution procedure and stimulated Cu forms.
Study of the effect of inducement on absorb and transfer of heavy metals by plant showed that, the amout of Cu and Zn absorbed by plant was increased evidently by adding EDTA, as Zn and Cd were concerned, similar phenomenon presented when adding monosodium glutamated waste water or wood fungi contagion. Besides, except citric acid waste water, addition promoted the transference of heavy metals from root to shoot in plant.
The chemical behavior of paddy soil was difference between with rhizosphere and non-rhizosphere under inducement. The pH value of rhizosphere was reduced by inducement, especially adding monosodium glutamate waster water. The phenomenon that heavy metal concentration in rhizosphere was higher than that of non-rhizosphere showed that, the activation rate was greater than the rate of plant absorbing and matter passing from non-rhizosphere. The most evident effect of addition on chemical behavior of Cu and Zn was EDTA, followed with monosodium glutamate waste water and citric acid waste water. In addition, microbe biomass in rhizosphere under inducement was higher than that of non-rhizospher, which resulted in increasing of DOC concentration in rhizosphere.
The solubility sequence of heavy metals in Fuyan paddy soil was Zn>Pb>Cu, it was changed to Zn>Cu>Pb effected by organic complexing agent. Similarly, the solubility sequence of heavy metals in Qingzi soil was Zn> Cu>Pb, it was changed to Cu>Zn>Pb effected by organic complexing agent. The change of soluble and ionic heavy metal concentration in soil solution showed that, the activity and plant availability of heavy metals was higher than that of the check.
The existing forms of heavy metal in soils were greatly changed by root and inducement. The amount of CaCI2 extractable heavy metal was increased elfected by inducement. As the transform of Cu was concerned, the Cu bounded to carbonate and organic matter bound Cu was
strongly activated by inducement , so them were easily absorbed by plant compared with others forms. The Fe/Mn oxide bound Cu and residual Cu were poorly available, they could slightly transformed to other forms induced by EDTA and monosodium glutamate waster water.
Study of availability of various Cu fractions in soil-plant system and its inducing effect showed that, the sequence of availability of Cu forms to plant is soluble plus exchangeable Cu and organic matter bound Cu > Cu bounded to carbonate > Fe/Mn oxide bound Cu > residual Cu. Effect of EDTA on dissolving of Cu from soil and absorb and transfer of plant was greater than that of monosodium glutamate waste water and citric acid waste water.
诱导措施对植株的吸收与转运重金属方面有不同程度的促进作用。EDTA对Cu，Pb的效果较明显；味精废水与木屑真菌腐化物对Zn、Cd的活化效果较好；柠檬酸废水对促进香根草吸收重金属的效果较好，而对高羊茅较弱。EDTA和味精废水对四种重金属在植物体内的运输均有较大的促进作用；柠檬酸废水对Pb在植株体内的运输起抑制作用；除Cd外，柠檬酸废水和淹水处理均使重金属的运输能力增高；真菌腐化物对香根草吸Zn有负面作用，而对其它重金属效果较好。
在外源物质影响下，富阳水稻土根际土壤化学行为异于非根际。诱导措施使富阳水稻土植物根际pH降低，产生“根际酸化”现象，其中以味精废水效果最为明显；在根系和外源物质作用下，根际土壤溶液中重金属含量均高于非根际，外源物质活化程度超过了植物吸收与根际向非根际转移速度之和，其对Cu、Zn的溶出效果顺度为：EDTA＞味精废水＞柠檬酸废水＞木屑真菌腐化物。另外，根际微生物量均高于非根际，不同诱导措施对促进根系分泌的作用不同，其中以味精废水与淹水处理的效果最为明显。根泌物与根际微生物增加提高了根际DOC浓度的增加，但淹水处理降低了根际DOC浓度。
富阳水稻土中重金属的溶解度顺序为Zn＞Pb＞Cu，在有机络合剂作用下，其顺序转变为Zn＞Cu＞Pb；青紫泥中重金属的溶解度顺序为Zn＞Cu＞#b，在有机络合剂作用下，其顺序转变为Cu＞Zn＞Pb。有机络合剂使得土壤溶液中可溶性与离子态重金属的浓度改变，反映了其活性与可利用性较对照不同。
诱导措施与植物根系对土壤重金属的存在形态产生了较大影响。诱导措施对土壤有效态重金属(CaCl_2提取态)的活化程度高于植物吸收与向非根际转移速度之和。以Cu的形态转化为例，诱导措施与根系作用对碳酸盐结合态与有机结合态的活化效果较好，且植物吸收也较强；铁锰氧化物结合态和残渣态使Cu无效化，在EDTA与味精废水作用下，它们可能向可利用性较高的形态转化。
Cu各形态的植物可利用性的顺序为水溶态、交换态、有机结合态＞碳酸盐结合态＞铁锰
氧化物结合态＞残渣态；其中有机结合态最易被植物吸收，而水溶态和交换态最易被植物所
转运。CU各形态受活化俏况oJ植物吸收俏况与有机络合剂的成分与性质有关，EDTA对CU
形态的溶出与促进植物吸收与转运CU素的效果最为明显，味精废水次之。
Recently, phytoextraction theory and application has become a focus in environmental scientific area. In this paper, the plant effect and soil chemical behavior under inducement, including adding EDTA, citric acid waste water, monosodium glutamate waster water and wood fungi contagion was studied by pot experiment, heavy metal activity was evaluated with a cation exchange batch procedure, and the plant availability of heavy metal forms was evaluated with partial dissolution procedure and stimulated Cu forms.
Study of the effect of inducement on absorb and transfer of heavy metals by plant showed that, the amout of Cu and Zn absorbed by plant was increased evidently by adding EDTA, as Zn and Cd were concerned, similar phenomenon presented when adding monosodium glutamated waste water or wood fungi contagion. Besides, except citric acid waste water, addition promoted the transference of heavy metals from root to shoot in plant.
The chemical behavior of paddy soil was difference between with rhizosphere and non-rhizosphere under inducement. The pH value of rhizosphere was reduced by inducement, especially adding monosodium glutamate waster water. The phenomenon that heavy metal concentration in rhizosphere was higher than that of non-rhizosphere showed that, the activation rate was greater than the rate of plant absorbing and matter passing from non-rhizosphere. The most evident effect of addition on chemical behavior of Cu and Zn was EDTA, followed with monosodium glutamate waste water and citric acid waste water. In addition, microbe biomass in rhizosphere under inducement was higher than that of non-rhizospher, which resulted in increasing of DOC concentration in rhizosphere.
The solubility sequence of heavy metals in Fuyan paddy soil was Zn>Pb>Cu, it was changed to Zn>Cu>Pb effected by organic complexing agent. Similarly, the solubility sequence of heavy metals in Qingzi soil was Zn> Cu>Pb, it was changed to Cu>Zn>Pb effected by organic complexing agent. The change of soluble and ionic heavy metal concentration in soil solution showed that, the activity and plant availability of heavy metals was higher than that of the check.
The existing forms of heavy metal in soils were greatly changed by root and inducement. The amount of CaCI2 extractable heavy metal was increased elfected by inducement. As the transform of Cu was concerned, the Cu bounded to carbonate and organic matter bound Cu was
strongly activated by inducement , so them were easily absorbed by plant compared with others forms. The Fe/Mn oxide bound Cu and residual Cu were poorly available, they could slightly transformed to other forms induced by EDTA and monosodium glutamate waster water.
Study of availability of various Cu fractions in soil-plant system and its inducing effect showed that, the sequence of availability of Cu forms to plant is soluble plus exchangeable Cu and organic matter bound Cu > Cu bounded to carbonate > Fe/Mn oxide bound Cu > residual Cu. Effect of EDTA on dissolving of Cu from soil and absorb and transfer of plant was greater than that of monosodium glutamate waste water and citric acid waste water.
引文
1．陈有铿，陶澍，邓宝山，张学青，2000，小麦根际环境中铜和钳形态的变化，环境科学学报，20(3)：365-369
2．龚月桦，王俊儒，1998，高俊凤，植物修复技术及其在环境保护中的应用，农业环境保护，17(6)：268-270
3．谷利源，1998美培育出可消除重金属污染的白杨树，中国科学报，10．14
4．何宏平，郭九本，谢先德，彭金莲，1999，蒙脱石等粘土矿物对重金属离子吸附选择性的实验研究，矿物学报，19(2)：231-235
5．蒋先军．骆永明．赵其国，2000，土壤重金属污染土壤的植物提取修复技术及其应用前景，农业环境保护．19(3)：179-183
6．刘清，王子健，汤鸿霄，1996，重金属形态与生物毒性及生物有效性关系的研究进展，环境科学，17(1)：89—92
7．李瑞秋 高小彦．1991，淹水对下米苗某些生理和形态的影响，植物学报，33(6)：473-477
8．李永涛，吴启堂，1997，土壤污染治理方法研究．农业坏境保护，16(3)：118-122
9．骆永明，2000，强化植物修复的整合诱导技术及其环境风险，土壤，32(2)：57-61，74
10．林琦，郑春荣，1998，陈怀满，根际环境中镉的形态转化，土壤学报，35(4)：461-467
11．林稚兰，田哲贤，1998，微生物对重金属的抗性及解毒机理，微生物学通报，25(1)：36-39
12．沈宏，曹志洪，胡正义，1999，土壤活性有机碳的表征及其生态效应，生态学杂志，18(3)：32-38
13．沈振国，1998a，不同锌处理下重金属超量积累植物Thlaspi caerulescens对养分的吸收，南京学业大学学报，21(2)：47-53
14．沈振国，刘友良，1998b，重金属超量积累机物研究进展，植物生理学通讯，34(2)：133-139
15．沈振国，刘友良，陈怀满，1998c，螯合剂对重金属超量积累植物Thlaspi caerulescens的锌、铜、锰和铁吸收的影响，植物生理学报，24(4)：340-346
16．邵宗臣等，几种氧化铁的离子吸附特性研究，土壤学报，1984．21(2)：153
17．唐世荣，1996a．超积累植物，农业环境与发展，13(3)：14-18
18．唐世荣．黄吕勇，朱祖祥，1996b，污染土壤的植物修复技术及其研究进展，上海环境科学，15(12)：37-39，47
19．吴龙华，骆永明，黄焕忠，2000a，铜污染土壤修复的有机调控研究Ⅰ．可溶性有机物和EDTA对污染红壤铜的释放作用，土壤，32(2)：62-66
20．吴龙华，骆水明，卢蓉晖，黄焕忠，2000b，铜污染土壤修复的有机调控研究Ⅱ．根际土壤铜的有机活化效应，32(2)：67-70
21．王保军，1996，微生物与重金属的相互作用，重庆环境科学，18(1)：35-38
22．王鹏新等，1993，娄土可给态镍浸捉方法的研究，环境科学学报，13(2)：223
23．王宏康，1991，土壤中金属污染的研究进展，环境化学，10(5)：35-41
24．王荣，沈其荣，史瑞和，黄东迈，1996，土壤微生物量及其生态效应，南京农业大学学报，19(4)：45-51
25．余贵芬，青长乐，1998，重金属污染土壤治理研究现状，农业环境与发展，15(4)：22-24
26．杨仁斌，曾清如，周细红，铁柏表，刘声扬，2000，植物根系分泌物对铅锌尾矿污染土壤中重金属的活化效应．农业环境保护，19(3)：152-155
27．杨居荣，查燕．刘虹．污染稻、麦籽实中Cd、Cu、Pb的分布及其存在形态初探．中国环境科学，1999，19(6)：500-504
28．杨居荣，黄翌，1994，植物对重金属的耐性机理，生态学杂志，13(6)：20-26
29．郑绍建，胡霭堂，1995，淹水对污染土壤镉形态转化的影响，环境科学学报，15(2)：142-147
30．张淑香，高子勤，2000a,连作障碍与根际微生态研究Ⅱ．根系分泌物与酚酸物质，应用生态学报，11(1)：152-156
31．张淑香，高子勤，刘海玲，2000b，连作障碍与根际微生态学研究Ⅲ．土壤酚酸物质及其生物学效应，应用生态学报，11(5)：741-744
32．张玉秀，柴团耀，1999，植物耐重金属机理研究进展，植物学报，41(5)：453-457
33．中国科学院南京土壤所，土壤理化分析[M]，上海：上海科技出版社，1977
34. Allard B., 1991. Humic substances in the aquatic and terrestrial environment[M], Springer-Verlag, New York
35. Baath E., 1989. Effects of heavy metal in soil on microbial processed and populaton. Water Air and soil pollution 47:335-379
36. Baker A. J. M., 1981. Accumulators and excluders-strategies in the response of plants to heavy metals. Journal of plant Nutrition 3,643
37. Baker Alan J. M. and Newman Lee A., 2000. Selecting plants for phytoremediation: the resources available and their practical utilization in the field, International Conference of Soil Remediation, Hangzhou, China, 146-150
38. Banuelos G. S., et al., 1992. Journal of Environmental Science and health. Part A Environmental Science and Engineering 27: 283-298
39. Banelos G. S., 1998. Use of crop rotation in phytoremediation of Se. Proceedings of the 16th World Congress of Soil Science. Montpellier, France
40. Barber D. A., Lee R. B., 1974. The effect of microorganisms on the absorption of manganese by plants. New Phytol. 73:97-106
41. Bennett F. A., et al., 1998. Ferilization to enhance phytoremediation in: Brookes R. R., Plant that hyperaccumulate heavy metal. CAB. International, Wallingford, 249-260
42. Bernal M. P., Mcgrath S. P., Miller A. J. and Baker A. J. M., 1994a. Comparison of the chemical changes in the rhizosphere of the nickel hyperaccumulator Alyssum murade with the non-accumulator Raphanus sativus. Plant and soil 164: 251-159
43. Bernal M. P. and McGrath S. P., 1994b. Effect of pH and heavy metal concentrations in Iolution culture on the proton release, growth and element composition of Alyssum murale and Raphanus sativus L. Plant and Soil 166:83-92
44. Blaylock M. J., Salt D. E,, Kushenkov S., Zakharova O., Gussman C., 1997. Enhanced accumulation of Pb in Indian mustard by soil applied chelating agents. Environ. Sci. Technol. 31:860-865
45. Bleeker A B., Schaller G. E., 1996. The mechanism of ethylene perception. Plant Physiol 111: 653-660
46. Bromfield, S. M., 1958. The properties of a biologiacally formed manganese oxide, its availability to oats and its solution by root washing. Plant and soil, 9:325-328
47. Chai T. Y., Didierjean L., Burkard G, Genot G, 1998. Expression ora green tissue-specific 11 kDa proline-rich protein gene in bean in response to heavy metals. Plant Sci. 133: 47-56
48. Chatthai M Kaukinen K. H., Tranbarger T. J., Gupta P. K., Misra S., 1997. The isolation of a novel metallothionein-related cDNA expressed in somatic and zygotic embryos of Douglas-fir:
regulation by ABA,osmoticum,and metal ions.Plant Mol Biol.34:243-254
49． Chen H.M.Zheng C.R.,Tu C.,Shen Z.G,2000． Chemical methods and phytoremediation of soil contaminated with heavy metals.Chemosphere 41:229-234
50． Cohen C.K.,Fox T.C.,Garvin D.F.,Kochian L.V.,1998． The role of iron deficiency stress responses in stimulating heavy-metal transport in plants.Plant Physiol 116:1063-1072
51． Crowley D.E.,Wang Y.C.,Reid C.P.P..Szaniszlo P.J., 1991． Mechanisms of iron acquisition from siderophores by microorganisms and plants.Plant and Soil 130:179-198
52． Ebbs,S.D.,Lasat.M.M.,Brady,D.J..Cornish,J.,Gordon,R.and L.V.Konchian,1997． Heavy metals in the environment: phytoextraction of cadmium and zinc from a contaminated soil.J.Evniron.Qual.,26:1424-1430
53． Esnaola M.V.,Millan E.,1998． Evaluation of heavy metal lability in polluted soils by a cation exchange batch procedure.Environmental pollution 99: 79-86
54． Evans K.M.et al., 1992． Expression of the pea mettallothionein-like gene PsMTAin Escherichia coli and Arabidopsis thaliana and analysis of trace metal ion accumulation: Implications for PsMTA function.Plant Molecular Biology 20:1019-1028
55． Fimmel F.M,Christman R.F.,1998． Humic substances and their roles in the environment[M],John Wiley & Sons,Chichester
56． Foley R.C.,Ling Z.M..Sing K.B..1997． Analysis of type I metallothioein cDNA in Vicia faba.Plant Mol Biol.33: 583-591
57． Gadde R R et al.1974． Studies on heavy metal absorpted by hydrous iron and manganese oxides.Analy.Chem.46(13) : 2022
58． GoGo,G.H.and H.M.,Reisenauer ,1980． Plant effect of soil manganese availability.Soil.Sci.Soc.Am.J.,44:993-995
59． Grimshaw R.G, 1997． Vetiver grass technology and its application in China.Vetiver Newsletter 1,4-6
60． Harter,R.D.,1983． Effect of soil pH on adsorption of lead,copper,zinc and nickel.Soil Sci.Soc.Am.,47,47-51
61． Haynes R.J.,1990． Active ion uptake and maintenance of cation-anion balance,A critical exanination of their role in regulating rhizosphere.Plant and Soil 126:247-264
62． Hamilton M.A.,Westermann D.T..1991． Comparison of DTPA and resin extractable soil Zn to plant Zn uptake.Communications in Soil Science and Plant Analysis 22:517-528
63． Hsieh H.,Liu W.,Huang P.C.,1995． A novel stress-inducible metallothionein-like gene from rice.Plant Mol Biol.28:381-389
64． Huang J.W,Cunningham S.D.,1996． Chromium reduction in Pseudomonas putida.Appl.Environ.Microbiol.56:2268-2270
65． Huang J.W., Jianjun Chen, William R., Berti and Scott D.Cunningham, 1997． Phytoremediation of lead-contaminated soils: role of synthetic chelates in lead phytoextraction.Environ.Sci.Technol.31:800-805
66． Jacpueline V Shanks and John Morgan,1999． Plant 'hairy root' culture.Current Opinion in Biotechnology 10:151-155
67． Jean Louis Morel,Karen Perronnet,Emilie Gerard,Christophe Schwartz and Guillaume Echevam'a,2000． The remediation of metal contaminated soils.International Conference of Soil Remediation,Hangzhou.China,151-155
68． Jianvvei W.Huang,Jianjun Chen.William R.Berti.and Scott D.Cunningham, 1997．
Phytoremediation of lead-contaminated soils: role of synthetic chelates in lead phytoextraction.Environ.Sci.Technol.31:800-805
69． Jorg,GerK,1992． Phosphate,aluminium and iron in the soil solution of three different soil in relation to varying cocerntration of citric acid.Z Pflanzenernahr.Bodenk 155:339-343
70． Karenlampi S.,Schat H.,Vangronsveld J.,Verkleij J.A.C.,Van der Lelie D., Mergeay M.,Tervahauta A.I., 2000． Genetic engineering in the improvement of plants for phytoremediation of metal polluted soils.Environmental Pollution 107:225-231
71． Kawashima 1． ,Kennedy T.D.,Chino M..Lane B.G,1992． Wheat EC metallothionein genes like mammalian Zn2+ metallothiomein genes,wheat Zn2+ metallothionein genes are conspicuously expressed during embryogenesis.Eur J Biochem,209: 971 ~976
72． Kennedy C.D.and Comfort S.d.,1986． The action of divalent Zn,Cd,Hg,Cu and Pb on the transrootpotential and H+ efflux of excised roots.J.Exp.Bot.38:800-817
73． Kiekens L et al.1984． Chemical activity and biological effect of sludge-borne heavy metals and inorganic metal salts added to soil.Plant and Soil 79(1) : 89
74． Koricheva J.,Roy S.,Vranjic J.A.,Haukioja E,Hughes P.R.,Hnninen O.,1997． Antioxidant responses to simulated acid rain and heavy metal deposition in birch seedlings.Environ Pollut.95:249-258
75． Kramer U.,Cotter-Howells J.D.,Charnock J.M.,Baker A.J.M.,Smith J.A.C.,1996． Free histjdine as a metal chelator in plants that accumulate nickel.Nature 379: 635-638
76． Knight B.,Zhao F.J.,McGrath S.P.and Shen Z.G,1997． Zinc and cadium uptake by the hyperaccumulator Thlaspi caerulescens in contaminated soils and its effects on the concentration and chemical speciation of metal in soil solution.Plant and soil 197: 71-78
77． Kuper H.,Zhao F.J.and McGrath S.P.,1999． Cellular compartmentation of zincin leaves of the hyperaccumulator Thlaspi caerulescens.Plant Physiol.119: 305-311
78． Lasat M.M.,Baker A J.M.,and Kochian L.V.,1998． Altered zinc compartmentation in the root symplasm and stimulated Zn2+ absorption into the leaf as mechanisms involved in Zinc hyperaccumulation in Thlaspi caerulescens.Plant Physiol.II 8:875-883
79． Lasat M.M..Baker A.J.M.and Kochian L.V.,1996． Physiological Characterization of root Zn2+ absorption and translocation to shoots in Zn hyperaccumulator and nonaccumulator species of Thlaspi .Plant Physiol.112: 1715-1722
80． Lasat M.M.,Novell W.A.and Kochian L V.,1997． Potential for phytoextraction of 137Cs from a contaminated soil.Plant and Soil 195:99-106
81． Lasat M.M.,Pence N.S.,Garvin D.F.,Ebbs S.D.and Kochian L.V.,2000． Molecular physiology of zinc transport in the Zn hyperaccumulator Thlaspi caerulescens.J.Exp.Bot.51:71-79
82． Lee J.,Reeves R.K.,Brooks R.R.,Jaffre T.1978． The relation between nickel and citric acid in some nickel-accumulationplants.Phytochemistry 17,1033-1035
83． Liang J.,Schoenau J.J.,1995． Development of resin membranes as a sensitive indicator fo heavy metal toxicity in the soil environment.International Journal of Environmental Analytical Chemistry 59: 265-275
84． Lorenz S E et al.,1997． Cadium and zinc in plant and soil solution from contaminated soils Plant and soil 189:21-31
85． Luo Y.M.,1999,In: Proceeding of Extended Abstracts of 5th International Conference on the Biogeochemistry of Trace Elements 2:882-884
86． Ma J.F.,Hiradate S.,Matsumoto II.,1998． High aluminum resistance in buckwheat II.Oxalic acid detoxifies aluminum internally.Plant Physiol.117:753-759
87． Malin Mejare and Leif Bulow,2001． Metal-binding proteins and peptides in bioremediation and phytoremediation of heavy metals.Trends In biotechnology 19(2) :327-335
88． Marschner H.,1997,Mineral Nutrition of Higher Plants,2nd Edition.Academic Press,London
89． McGraph S.P.,Shen Z.G,and Zhao F.J.,1997． Heavy metal uptake and chemical changes in the rhizosphere of Thlaspi caerulescens and Thlaspi ochroleucum grown in contaminated soils.Int Pa and Soil 188: 153-159
90． Meagher R B.,2000． Phytoremediation of toxic elemental and organic pollutants.Plant biology 3:153-162
91． Mench,Mand E.; Martin,1991． Mobilization of cadmium and other metal from two soils by root exudates of Zea mays L.,Nicotiana tobacum,L.and Nicotiana,L.,Plant and soil 132:187-196
92． Mench.M.,Morel J.L.and Guckert A.,1987． Metal binding properties of high molecular weight solute exudates from maize root.Biol.Ferti.Soils: 165-169
93． Mench,M.,J.L.Morel,A.Guchert and Guillet,1988． Metal binding with root exudates of low molecular weight.J.Soil Sci.,39:521-527
94． Mench M.,Vangronsveld J.,Didier V.and Clijsters H.,1994． Evaluation of metal mobility,plant availability and immobilization by chemical agents in limed soil.Environmental Pollution.86: 279-286
95． McGrath S.P.,1998． In: Plants that Hyperaccumulate Heavy metals.Brook R R (ed),CAB International,Wallingford,UK,261-287
96． Michael J.,Blaylock David E., Salt Slavik Dushenkov,Olga Zakharova,Christopher Gussman,Yoram Kapulnik,Burt K.Ensley,and llya Raskin,1997． Enhanced accumulation of Pb in Indian Mustard by soil-applied chelating agents.Environ.Sci.Techno).31:860-865
97． Morel,J.L.,Guckert A.,and M.Mench, 1983． Studies of interaction between root exudates-heavy metals, I .Choice of method for determination of the capacity and energy of metal binding by the exudates.Oecol Plant 4:363-376
98． Muller D.F.,Van Oort,B.Gelie,Balabane M.,2000． Strategies of heavy metal uptake by three plant species growing near a metal smelter.Environmental Pollution 109:231-238
99． Nanda Kumar P.B.A.,Viatcheslav Dushenkov,Harry Motto,and llya Raskin,1995． Phytoextraction: The use of plants to remove heavy metals from soils,Environ.Sci.Technol.29:1232-1238
100． Nardi,S.,G Dell'agnola and Albuzio A.,1986． Changes in the molecular complexity of humus caused by organic acid.Agrochimica 30:149-159
101． Newman L. A., Strand S. E.,Choe N., Duffy J., Ekuan G.1997． Uptake and biotransformation of trichloroethylene by hybrid poplars.Environ. Sci. Technol. 31,1062-1067
102． Qian P.,Schoenau J.J.,Huang W.Z.,1992． Use of ion exchange membranes in routine soil testing.Communications in Soil Science and Plant Analysis 23: 1791-1804
103． Raskin I.,Smith R.D.,Salt D.E.,1997． Phytoremediation of metals: using plants to remove pollutants from the environment.Curr.Opin.Biotechnol.8: 221-226
104． Robinson B et al.,1998． The potential of some hyperaccumulators for phytoremediation of contaminated soils.Proceedings of the 16th World Congress of Soil Science.Montpellier.
France
105． Salt,D.A.,Smith,R.D.and Raskin I.1998． Phytoremediation,Annual Review of Plant Physiology and Plant Molecular Biology 49:643-668
106． Salt D.E.,Prince R.C.,Baker A.J.M.,Raskin I.,Pickering I.J.,1999． Zinc ligands in the metal hyperaccumulator Thlaspi caerulescens as determined using x-ray absorption spectroscopy.Environ Sci Technol 33:713-717
107． Salt D.E.,Prince R.C.,Pickering 1． J.,Raskin I.,1995． Mechanisms of cadmium mobility and accumulation in Indian mustard.Plant Physiol.109:1427-1433
108． Salt D.E.,Wagner G J.,1993． Cadmium transport across tonoplast of vesicles from oat roots.Evidence for a Cd2+/H+antiport activity.J Biol Chem 268:12297-12302
109． Salt D.E.,Blaylock M.,Kumar P.B.A.N.,Dushenkov V.,Ensley,B.D.,Chet,L,Raskin,L.,1995． Phytoremediation: a novel strategy for the removal of toxic metals from the environment using plants.Biotechnology 13: 468-474
110． Salt.D.E..Smith.R.D.,Raskin.1． .1998． Phytoremediation,Annu.Rev.Plant Physiol.Blant Mol.Biol.49,643-668
111． Sanita di Toppi L,Gabbrielli R.,1999． Response to cadmium in higher plants.Environmental and Experimental Botany41:105-130
112． Shen Z.G,Zhao F.J.and McGrath S.R,1997． Plant,Cell and Environment 20:898-906
113． Sinclair,A.H.,Mackie-Dawson L.A.and Linehean,D.J.,1990． Micronutrient inflow rates and mobilization into soil solution in the root zones of winter wheal(Tritricum aestivum L.).plant soil 122:143-146
114． Steven N.Whiting ,Mark P.De Souza,and Norman terry,2001． Rhizosphere Bacteria Mobilize Zn for Hyperaccumulation by Thlaspi Caerulescens.Environment Science and Technology 35,3144-3150
115． Steven N.Whiting,Jonathan R.Leake .Steven P.McGrath,2001． Hyperaccumulation of Zn by Thlaspi Caerulescens Can Ameliorate Zn Toxicity in the Rhizosphere of Cocropped Thlaspi arvense.Environment Science and Technology 35: 3237-3241
116． Sun B.,Zhao F.J..Lombi E..McGrath S.P.,2001． Leaching of heavy metals from contaminated soils using EDTA.Environmental Pollution 113:110-120
117． Sugiura Y.,Nomoto K.,1984． Phytosiderophores: Structure and properties of mugieic acids and their metal complexes.Structure and Bonding 58:107-135
118． Tessler A.,Campbell P.G C.,and M.Blsson,1979． Sequential extraction procedure for the speciation of paniculate trace metals.Analytical Chemistry 51(7) : 844-851
119． Taylor G J.,1987． Exclusion of metals from the symplasm: apossible mechanism of metal tolerance in higher plants.Journal of Plant Nutrition 10,1213
120． Vangronsveld J.,Ann Ruttens,Colpaert J.and D.van der Lelie,2000． In situ fixation and phytostabilization of metals in polluted soils,International Conference of Soil Remediation,hangzhou,China,262-267
121． van Raij,B.,Quaggio J.A.,da Silva N.M.,1986． Extraction of phosphorus,calcium and magnesium from soils by an ion-exchange resin procedure.Commuincations in Soil Science and Plant Analysis 17: 547-566
122． Wang J.,Bill P.E.,Mark T.N..Geoge J.W..1991． Computer-simulated evaluation of possible mechanism for quenching heavy metal ion activity in plant vacuoles.Plant physiol.97:1154-1160
123． Webb M.J.,Norvell W.A.,Welch R.M.,Graham R.D.,1993． Using a chelate-buffered nutrient solution to establish the critical solution activity of Mn2+ required by barley(Hordeum vulgare L.).Plant and Soil 153:195-205
124． Wenzel,W.W.,Puschenreiter,M.and Horak O.,2000． Role and manipulation of the rhizosphere in soil remediation/revegetation,International Conference of Soil Remediation Hangzhou,China,176-180
125． Whitelaw C.A.,Le Huquer J.A.,Thurman D.A.,Tomsett A.B..1997． The isolation and characterization of type II metallothionein-like genes from tomato (Lycopersicim esculemlum L).Plant Mol Biol.33:503-511
126． Wu Q.T.,1989． Cadmium bioavailibility in soil-system.These de Doctorat de 1'INPL,Nancy France
127． Xian X.1989． Effect of chemical forms of cadmium,zinc ,and lead in polluted soils on their uptake by cabbage plants.Plant and Soil 113(2) :257
128． Xian X.F.and Shokhifard G I.,1989． Effect of pH on chemical forms and plant availability of cadium,zinc and lead in contaminated soils.Water,Air and Soil Pollution 45: 265-273
129． Youssef,R.A.and M.Chino,1989． Root-induce chages in the rizhosphere of plant II.Distribution of heavy metal across the rhizosphere in soils,Soil Sci.Plant Nutr.,35:609-621
130． Zhang H.L.,Zheng C.R.,Chen H.M.,1987． Study on controlling cadmium absorption by crops in cadmium contamination soil(I).Agro-Environmental Protection 6(3) :27-29
2．龚月桦，王俊儒，1998，高俊凤，植物修复技术及其在环境保护中的应用，农业环境保护，17(6)：268-270
3．谷利源，1998美培育出可消除重金属污染的白杨树，中国科学报，10．14
4．何宏平，郭九本，谢先德，彭金莲，1999，蒙脱石等粘土矿物对重金属离子吸附选择性的实验研究，矿物学报，19(2)：231-235
5．蒋先军．骆永明．赵其国，2000，土壤重金属污染土壤的植物提取修复技术及其应用前景，农业环境保护．19(3)：179-183
6．刘清，王子健，汤鸿霄，1996，重金属形态与生物毒性及生物有效性关系的研究进展，环境科学，17(1)：89—92
7．李瑞秋 高小彦．1991，淹水对下米苗某些生理和形态的影响，植物学报，33(6)：473-477
8．李永涛，吴启堂，1997，土壤污染治理方法研究．农业坏境保护，16(3)：118-122
9．骆永明，2000，强化植物修复的整合诱导技术及其环境风险，土壤，32(2)：57-61，74
10．林琦，郑春荣，1998，陈怀满，根际环境中镉的形态转化，土壤学报，35(4)：461-467
11．林稚兰，田哲贤，1998，微生物对重金属的抗性及解毒机理，微生物学通报，25(1)：36-39
12．沈宏，曹志洪，胡正义，1999，土壤活性有机碳的表征及其生态效应，生态学杂志，18(3)：32-38
13．沈振国，1998a，不同锌处理下重金属超量积累植物Thlaspi caerulescens对养分的吸收，南京学业大学学报，21(2)：47-53
14．沈振国，刘友良，1998b，重金属超量积累机物研究进展，植物生理学通讯，34(2)：133-139
15．沈振国，刘友良，陈怀满，1998c，螯合剂对重金属超量积累植物Thlaspi caerulescens的锌、铜、锰和铁吸收的影响，植物生理学报，24(4)：340-346
16．邵宗臣等，几种氧化铁的离子吸附特性研究，土壤学报，1984．21(2)：153
17．唐世荣，1996a．超积累植物，农业环境与发展，13(3)：14-18
18．唐世荣．黄吕勇，朱祖祥，1996b，污染土壤的植物修复技术及其研究进展，上海环境科学，15(12)：37-39，47
19．吴龙华，骆永明，黄焕忠，2000a，铜污染土壤修复的有机调控研究Ⅰ．可溶性有机物和EDTA对污染红壤铜的释放作用，土壤，32(2)：62-66
20．吴龙华，骆水明，卢蓉晖，黄焕忠，2000b，铜污染土壤修复的有机调控研究Ⅱ．根际土壤铜的有机活化效应，32(2)：67-70
21．王保军，1996，微生物与重金属的相互作用，重庆环境科学，18(1)：35-38
22．王鹏新等，1993，娄土可给态镍浸捉方法的研究，环境科学学报，13(2)：223
23．王宏康，1991，土壤中金属污染的研究进展，环境化学，10(5)：35-41
24．王荣，沈其荣，史瑞和，黄东迈，1996，土壤微生物量及其生态效应，南京农业大学学报，19(4)：45-51
25．余贵芬，青长乐，1998，重金属污染土壤治理研究现状，农业环境与发展，15(4)：22-24
26．杨仁斌，曾清如，周细红，铁柏表，刘声扬，2000，植物根系分泌物对铅锌尾矿污染土壤中重金属的活化效应．农业环境保护，19(3)：152-155
27．杨居荣，查燕．刘虹．污染稻、麦籽实中Cd、Cu、Pb的分布及其存在形态初探．中国环境科学，1999，19(6)：500-504
28．杨居荣，黄翌，1994，植物对重金属的耐性机理，生态学杂志，13(6)：20-26
29．郑绍建，胡霭堂，1995，淹水对污染土壤镉形态转化的影响，环境科学学报，15(2)：142-147
30．张淑香，高子勤，2000a,连作障碍与根际微生态研究Ⅱ．根系分泌物与酚酸物质，应用生态学报，11(1)：152-156
31．张淑香，高子勤，刘海玲，2000b，连作障碍与根际微生态学研究Ⅲ．土壤酚酸物质及其生物学效应，应用生态学报，11(5)：741-744
32．张玉秀，柴团耀，1999，植物耐重金属机理研究进展，植物学报，41(5)：453-457
33．中国科学院南京土壤所，土壤理化分析[M]，上海：上海科技出版社，1977
34. Allard B., 1991. Humic substances in the aquatic and terrestrial environment[M], Springer-Verlag, New York
35. Baath E., 1989. Effects of heavy metal in soil on microbial processed and populaton. Water Air and soil pollution 47:335-379
36. Baker A. J. M., 1981. Accumulators and excluders-strategies in the response of plants to heavy metals. Journal of plant Nutrition 3,643
37. Baker Alan J. M. and Newman Lee A., 2000. Selecting plants for phytoremediation: the resources available and their practical utilization in the field, International Conference of Soil Remediation, Hangzhou, China, 146-150
38. Banuelos G. S., et al., 1992. Journal of Environmental Science and health. Part A Environmental Science and Engineering 27: 283-298
39. Banelos G. S., 1998. Use of crop rotation in phytoremediation of Se. Proceedings of the 16th World Congress of Soil Science. Montpellier, France
40. Barber D. A., Lee R. B., 1974. The effect of microorganisms on the absorption of manganese by plants. New Phytol. 73:97-106
41. Bennett F. A., et al., 1998. Ferilization to enhance phytoremediation in: Brookes R. R., Plant that hyperaccumulate heavy metal. CAB. International, Wallingford, 249-260
42. Bernal M. P., Mcgrath S. P., Miller A. J. and Baker A. J. M., 1994a. Comparison of the chemical changes in the rhizosphere of the nickel hyperaccumulator Alyssum murade with the non-accumulator Raphanus sativus. Plant and soil 164: 251-159
43. Bernal M. P. and McGrath S. P., 1994b. Effect of pH and heavy metal concentrations in Iolution culture on the proton release, growth and element composition of Alyssum murale and Raphanus sativus L. Plant and Soil 166:83-92
44. Blaylock M. J., Salt D. E,, Kushenkov S., Zakharova O., Gussman C., 1997. Enhanced accumulation of Pb in Indian mustard by soil applied chelating agents. Environ. Sci. Technol. 31:860-865
45. Bleeker A B., Schaller G. E., 1996. The mechanism of ethylene perception. Plant Physiol 111: 653-660
46. Bromfield, S. M., 1958. The properties of a biologiacally formed manganese oxide, its availability to oats and its solution by root washing. Plant and soil, 9:325-328
47. Chai T. Y., Didierjean L., Burkard G, Genot G, 1998. Expression ora green tissue-specific 11 kDa proline-rich protein gene in bean in response to heavy metals. Plant Sci. 133: 47-56
48. Chatthai M Kaukinen K. H., Tranbarger T. J., Gupta P. K., Misra S., 1997. The isolation of a novel metallothionein-related cDNA expressed in somatic and zygotic embryos of Douglas-fir:
regulation by ABA,osmoticum,and metal ions.Plant Mol Biol.34:243-254
49． Chen H.M.Zheng C.R.,Tu C.,Shen Z.G,2000． Chemical methods and phytoremediation of soil contaminated with heavy metals.Chemosphere 41:229-234
50． Cohen C.K.,Fox T.C.,Garvin D.F.,Kochian L.V.,1998． The role of iron deficiency stress responses in stimulating heavy-metal transport in plants.Plant Physiol 116:1063-1072
51． Crowley D.E.,Wang Y.C.,Reid C.P.P..Szaniszlo P.J., 1991． Mechanisms of iron acquisition from siderophores by microorganisms and plants.Plant and Soil 130:179-198
52． Ebbs,S.D.,Lasat.M.M.,Brady,D.J..Cornish,J.,Gordon,R.and L.V.Konchian,1997． Heavy metals in the environment: phytoextraction of cadmium and zinc from a contaminated soil.J.Evniron.Qual.,26:1424-1430
53． Esnaola M.V.,Millan E.,1998． Evaluation of heavy metal lability in polluted soils by a cation exchange batch procedure.Environmental pollution 99: 79-86
54． Evans K.M.et al., 1992． Expression of the pea mettallothionein-like gene PsMTAin Escherichia coli and Arabidopsis thaliana and analysis of trace metal ion accumulation: Implications for PsMTA function.Plant Molecular Biology 20:1019-1028
55． Fimmel F.M,Christman R.F.,1998． Humic substances and their roles in the environment[M],John Wiley & Sons,Chichester
56． Foley R.C.,Ling Z.M..Sing K.B..1997． Analysis of type I metallothioein cDNA in Vicia faba.Plant Mol Biol.33: 583-591
57． Gadde R R et al.1974． Studies on heavy metal absorpted by hydrous iron and manganese oxides.Analy.Chem.46(13) : 2022
58． GoGo,G.H.and H.M.,Reisenauer ,1980． Plant effect of soil manganese availability.Soil.Sci.Soc.Am.J.,44:993-995
59． Grimshaw R.G, 1997． Vetiver grass technology and its application in China.Vetiver Newsletter 1,4-6
60． Harter,R.D.,1983． Effect of soil pH on adsorption of lead,copper,zinc and nickel.Soil Sci.Soc.Am.,47,47-51
61． Haynes R.J.,1990． Active ion uptake and maintenance of cation-anion balance,A critical exanination of their role in regulating rhizosphere.Plant and Soil 126:247-264
62． Hamilton M.A.,Westermann D.T..1991． Comparison of DTPA and resin extractable soil Zn to plant Zn uptake.Communications in Soil Science and Plant Analysis 22:517-528
63． Hsieh H.,Liu W.,Huang P.C.,1995． A novel stress-inducible metallothionein-like gene from rice.Plant Mol Biol.28:381-389
64． Huang J.W,Cunningham S.D.,1996． Chromium reduction in Pseudomonas putida.Appl.Environ.Microbiol.56:2268-2270
65． Huang J.W., Jianjun Chen, William R., Berti and Scott D.Cunningham, 1997． Phytoremediation of lead-contaminated soils: role of synthetic chelates in lead phytoextraction.Environ.Sci.Technol.31:800-805
66． Jacpueline V Shanks and John Morgan,1999． Plant 'hairy root' culture.Current Opinion in Biotechnology 10:151-155
67． Jean Louis Morel,Karen Perronnet,Emilie Gerard,Christophe Schwartz and Guillaume Echevam'a,2000． The remediation of metal contaminated soils.International Conference of Soil Remediation,Hangzhou.China,151-155
68． Jianvvei W.Huang,Jianjun Chen.William R.Berti.and Scott D.Cunningham, 1997．
Phytoremediation of lead-contaminated soils: role of synthetic chelates in lead phytoextraction.Environ.Sci.Technol.31:800-805
69． Jorg,GerK,1992． Phosphate,aluminium and iron in the soil solution of three different soil in relation to varying cocerntration of citric acid.Z Pflanzenernahr.Bodenk 155:339-343
70． Karenlampi S.,Schat H.,Vangronsveld J.,Verkleij J.A.C.,Van der Lelie D., Mergeay M.,Tervahauta A.I., 2000． Genetic engineering in the improvement of plants for phytoremediation of metal polluted soils.Environmental Pollution 107:225-231
71． Kawashima 1． ,Kennedy T.D.,Chino M..Lane B.G,1992． Wheat EC metallothionein genes like mammalian Zn2+ metallothiomein genes,wheat Zn2+ metallothionein genes are conspicuously expressed during embryogenesis.Eur J Biochem,209: 971 ~976
72． Kennedy C.D.and Comfort S.d.,1986． The action of divalent Zn,Cd,Hg,Cu and Pb on the transrootpotential and H+ efflux of excised roots.J.Exp.Bot.38:800-817
73． Kiekens L et al.1984． Chemical activity and biological effect of sludge-borne heavy metals and inorganic metal salts added to soil.Plant and Soil 79(1) : 89
74． Koricheva J.,Roy S.,Vranjic J.A.,Haukioja E,Hughes P.R.,Hnninen O.,1997． Antioxidant responses to simulated acid rain and heavy metal deposition in birch seedlings.Environ Pollut.95:249-258
75． Kramer U.,Cotter-Howells J.D.,Charnock J.M.,Baker A.J.M.,Smith J.A.C.,1996． Free histjdine as a metal chelator in plants that accumulate nickel.Nature 379: 635-638
76． Knight B.,Zhao F.J.,McGrath S.P.and Shen Z.G,1997． Zinc and cadium uptake by the hyperaccumulator Thlaspi caerulescens in contaminated soils and its effects on the concentration and chemical speciation of metal in soil solution.Plant and soil 197: 71-78
77． Kuper H.,Zhao F.J.and McGrath S.P.,1999． Cellular compartmentation of zincin leaves of the hyperaccumulator Thlaspi caerulescens.Plant Physiol.119: 305-311
78． Lasat M.M.,Baker A J.M.,and Kochian L.V.,1998． Altered zinc compartmentation in the root symplasm and stimulated Zn2+ absorption into the leaf as mechanisms involved in Zinc hyperaccumulation in Thlaspi caerulescens.Plant Physiol.II 8:875-883
79． Lasat M.M..Baker A.J.M.and Kochian L.V.,1996． Physiological Characterization of root Zn2+ absorption and translocation to shoots in Zn hyperaccumulator and nonaccumulator species of Thlaspi .Plant Physiol.112: 1715-1722
80． Lasat M.M.,Novell W.A.and Kochian L V.,1997． Potential for phytoextraction of 137Cs from a contaminated soil.Plant and Soil 195:99-106
81． Lasat M.M.,Pence N.S.,Garvin D.F.,Ebbs S.D.and Kochian L.V.,2000． Molecular physiology of zinc transport in the Zn hyperaccumulator Thlaspi caerulescens.J.Exp.Bot.51:71-79
82． Lee J.,Reeves R.K.,Brooks R.R.,Jaffre T.1978． The relation between nickel and citric acid in some nickel-accumulationplants.Phytochemistry 17,1033-1035
83． Liang J.,Schoenau J.J.,1995． Development of resin membranes as a sensitive indicator fo heavy metal toxicity in the soil environment.International Journal of Environmental Analytical Chemistry 59: 265-275
84． Lorenz S E et al.,1997． Cadium and zinc in plant and soil solution from contaminated soils Plant and soil 189:21-31
85． Luo Y.M.,1999,In: Proceeding of Extended Abstracts of 5th International Conference on the Biogeochemistry of Trace Elements 2:882-884
86． Ma J.F.,Hiradate S.,Matsumoto II.,1998． High aluminum resistance in buckwheat II.Oxalic acid detoxifies aluminum internally.Plant Physiol.117:753-759
87． Malin Mejare and Leif Bulow,2001． Metal-binding proteins and peptides in bioremediation and phytoremediation of heavy metals.Trends In biotechnology 19(2) :327-335
88． Marschner H.,1997,Mineral Nutrition of Higher Plants,2nd Edition.Academic Press,London
89． McGraph S.P.,Shen Z.G,and Zhao F.J.,1997． Heavy metal uptake and chemical changes in the rhizosphere of Thlaspi caerulescens and Thlaspi ochroleucum grown in contaminated soils.Int Pa and Soil 188: 153-159
90． Meagher R B.,2000． Phytoremediation of toxic elemental and organic pollutants.Plant biology 3:153-162
91． Mench,Mand E.; Martin,1991． Mobilization of cadmium and other metal from two soils by root exudates of Zea mays L.,Nicotiana tobacum,L.and Nicotiana,L.,Plant and soil 132:187-196
92． Mench.M.,Morel J.L.and Guckert A.,1987． Metal binding properties of high molecular weight solute exudates from maize root.Biol.Ferti.Soils: 165-169
93． Mench,M.,J.L.Morel,A.Guchert and Guillet,1988． Metal binding with root exudates of low molecular weight.J.Soil Sci.,39:521-527
94． Mench M.,Vangronsveld J.,Didier V.and Clijsters H.,1994． Evaluation of metal mobility,plant availability and immobilization by chemical agents in limed soil.Environmental Pollution.86: 279-286
95． McGrath S.P.,1998． In: Plants that Hyperaccumulate Heavy metals.Brook R R (ed),CAB International,Wallingford,UK,261-287
96． Michael J.,Blaylock David E., Salt Slavik Dushenkov,Olga Zakharova,Christopher Gussman,Yoram Kapulnik,Burt K.Ensley,and llya Raskin,1997． Enhanced accumulation of Pb in Indian Mustard by soil-applied chelating agents.Environ.Sci.Techno).31:860-865
97． Morel,J.L.,Guckert A.,and M.Mench, 1983． Studies of interaction between root exudates-heavy metals, I .Choice of method for determination of the capacity and energy of metal binding by the exudates.Oecol Plant 4:363-376
98． Muller D.F.,Van Oort,B.Gelie,Balabane M.,2000． Strategies of heavy metal uptake by three plant species growing near a metal smelter.Environmental Pollution 109:231-238
99． Nanda Kumar P.B.A.,Viatcheslav Dushenkov,Harry Motto,and llya Raskin,1995． Phytoextraction: The use of plants to remove heavy metals from soils,Environ.Sci.Technol.29:1232-1238
100． Nardi,S.,G Dell'agnola and Albuzio A.,1986． Changes in the molecular complexity of humus caused by organic acid.Agrochimica 30:149-159
101． Newman L. A., Strand S. E.,Choe N., Duffy J., Ekuan G.1997． Uptake and biotransformation of trichloroethylene by hybrid poplars.Environ. Sci. Technol. 31,1062-1067
102． Qian P.,Schoenau J.J.,Huang W.Z.,1992． Use of ion exchange membranes in routine soil testing.Communications in Soil Science and Plant Analysis 23: 1791-1804
103． Raskin I.,Smith R.D.,Salt D.E.,1997． Phytoremediation of metals: using plants to remove pollutants from the environment.Curr.Opin.Biotechnol.8: 221-226
104． Robinson B et al.,1998． The potential of some hyperaccumulators for phytoremediation of contaminated soils.Proceedings of the 16th World Congress of Soil Science.Montpellier.
France
105． Salt,D.A.,Smith,R.D.and Raskin I.1998． Phytoremediation,Annual Review of Plant Physiology and Plant Molecular Biology 49:643-668
106． Salt D.E.,Prince R.C.,Baker A.J.M.,Raskin I.,Pickering I.J.,1999． Zinc ligands in the metal hyperaccumulator Thlaspi caerulescens as determined using x-ray absorption spectroscopy.Environ Sci Technol 33:713-717
107． Salt D.E.,Prince R.C.,Pickering 1． J.,Raskin I.,1995． Mechanisms of cadmium mobility and accumulation in Indian mustard.Plant Physiol.109:1427-1433
108． Salt D.E.,Wagner G J.,1993． Cadmium transport across tonoplast of vesicles from oat roots.Evidence for a Cd2+/H+antiport activity.J Biol Chem 268:12297-12302
109． Salt D.E.,Blaylock M.,Kumar P.B.A.N.,Dushenkov V.,Ensley,B.D.,Chet,L,Raskin,L.,1995． Phytoremediation: a novel strategy for the removal of toxic metals from the environment using plants.Biotechnology 13: 468-474
110． Salt.D.E..Smith.R.D.,Raskin.1． .1998． Phytoremediation,Annu.Rev.Plant Physiol.Blant Mol.Biol.49,643-668
111． Sanita di Toppi L,Gabbrielli R.,1999． Response to cadmium in higher plants.Environmental and Experimental Botany41:105-130
112． Shen Z.G,Zhao F.J.and McGrath S.R,1997． Plant,Cell and Environment 20:898-906
113． Sinclair,A.H.,Mackie-Dawson L.A.and Linehean,D.J.,1990． Micronutrient inflow rates and mobilization into soil solution in the root zones of winter wheal(Tritricum aestivum L.).plant soil 122:143-146
114． Steven N.Whiting ,Mark P.De Souza,and Norman terry,2001． Rhizosphere Bacteria Mobilize Zn for Hyperaccumulation by Thlaspi Caerulescens.Environment Science and Technology 35,3144-3150
115． Steven N.Whiting,Jonathan R.Leake .Steven P.McGrath,2001． Hyperaccumulation of Zn by Thlaspi Caerulescens Can Ameliorate Zn Toxicity in the Rhizosphere of Cocropped Thlaspi arvense.Environment Science and Technology 35: 3237-3241
116． Sun B.,Zhao F.J..Lombi E..McGrath S.P.,2001． Leaching of heavy metals from contaminated soils using EDTA.Environmental Pollution 113:110-120
117． Sugiura Y.,Nomoto K.,1984． Phytosiderophores: Structure and properties of mugieic acids and their metal complexes.Structure and Bonding 58:107-135
118． Tessler A.,Campbell P.G C.,and M.Blsson,1979． Sequential extraction procedure for the speciation of paniculate trace metals.Analytical Chemistry 51(7) : 844-851
119． Taylor G J.,1987． Exclusion of metals from the symplasm: apossible mechanism of metal tolerance in higher plants.Journal of Plant Nutrition 10,1213
120． Vangronsveld J.,Ann Ruttens,Colpaert J.and D.van der Lelie,2000． In situ fixation and phytostabilization of metals in polluted soils,International Conference of Soil Remediation,hangzhou,China,262-267
121． van Raij,B.,Quaggio J.A.,da Silva N.M.,1986． Extraction of phosphorus,calcium and magnesium from soils by an ion-exchange resin procedure.Commuincations in Soil Science and Plant Analysis 17: 547-566
122． Wang J.,Bill P.E.,Mark T.N..Geoge J.W..1991． Computer-simulated evaluation of possible mechanism for quenching heavy metal ion activity in plant vacuoles.Plant physiol.97:1154-1160
123． Webb M.J.,Norvell W.A.,Welch R.M.,Graham R.D.,1993． Using a chelate-buffered nutrient solution to establish the critical solution activity of Mn2+ required by barley(Hordeum vulgare L.).Plant and Soil 153:195-205
124． Wenzel,W.W.,Puschenreiter,M.and Horak O.,2000． Role and manipulation of the rhizosphere in soil remediation/revegetation,International Conference of Soil Remediation Hangzhou,China,176-180
125． Whitelaw C.A.,Le Huquer J.A.,Thurman D.A.,Tomsett A.B..1997． The isolation and characterization of type II metallothionein-like genes from tomato (Lycopersicim esculemlum L).Plant Mol Biol.33:503-511
126． Wu Q.T.,1989． Cadmium bioavailibility in soil-system.These de Doctorat de 1'INPL,Nancy France
127． Xian X.1989． Effect of chemical forms of cadmium,zinc ,and lead in polluted soils on their uptake by cabbage plants.Plant and Soil 113(2) :257
128． Xian X.F.and Shokhifard G I.,1989． Effect of pH on chemical forms and plant availability of cadium,zinc and lead in contaminated soils.Water,Air and Soil Pollution 45: 265-273
129． Youssef,R.A.and M.Chino,1989． Root-induce chages in the rizhosphere of plant II.Distribution of heavy metal across the rhizosphere in soils,Soil Sci.Plant Nutr.,35:609-621
130． Zhang H.L.,Zheng C.R.,Chen H.M.,1987． Study on controlling cadmium absorption by crops in cadmium contamination soil(I).Agro-Environmental Protection 6(3) :27-29