青葙对土壤锰的耐性和富集特征

通过盆栽试验,研究了青葙(Celosia argentea Linn.)对不同浓度(0、50、100、200、300、500 mg/kg)锰(Mn)污染土壤的吸收和积累特性。结果表明,青葙的锰含量、生物富集系数和生物量均随着土壤锰浓度的增加而增加。当土壤锰含量为300 mg/kg时,青葙生长良好。在锰浓度500 mg/kg时,青葙叶片边缘出现轻微褪绿现象,但是植株的生长未受到抑制,并且叶片生物量显著增加(P0.05)。此时,叶片中锰含量达到最大值42927 mg/kg,生物富集系数为69.20。青葙吸收的锰有95%—97%被转移到地上部分,表明该植物对锰具有很强转运能力。本研究的结果为利用青葙修复锰污染土壤提供了有力证据。     

重金属超富集植物及植物修复技术研究进展

植物修复技术（Phytoremediation)是近年来发展起来的一种主要用于清除土壤重金属污染的绿色生态技术,重金属超富集植物（hyperaccumulator)及植物修复技术是当前学术界研究的热点领域,目前虽已有Cd、Co、Cr、Cu、Mn、Ni、Pb、Zn等超富集植物发现的报道,但尚无一例报道来自于中国,中国具有广袤的国土面积、丰富的植物类型和多种（处）古老的矿山开采与冶炼场所,在中国开展超富集植物的寻找,研究与开发工作,将会有重要突破,并具有重要的理论与实践意义,本文拟就国内外在这一领域的研究进展作一简要综述。     

湘潭锰矿区植物资源调查及超富集植物筛选

通过设置样地,对湘潭锰矿区的植物资源进行了全面调查。结果表明:锰矿区植物丰富,共有28科,53种,植物以自然定居种为主,少见人工栽培种;生活史以多年生植物为主,少见1年生植物。群落结构上,以草灌丛为主,少见乔木种;当前锰矿区形成的以多年生草灌丛为主的局部群落,是原锰矿区植被在开采中被彻底破坏后,处在逐步向亚热带常绿阔叶林演替的一种初级阶段;其次,对矿区植物锰富集能力进行的分析表明,植物各组织(根、茎、叶)之间锰富集量差异明显,大部分物种地下部分锰含量大于地上部分,表现出一般植物的共性,只有少部分植物地上部分锰含量大于地下部分,表现出其特殊性;此外,植物种之间富集锰能力差异显著;莎草地上与地下部分锰含量均大于超富集植物10000mg.kg-1的临界浓度且富集系数与转移系数均大于1的超富集植物评价标准,表明其具有超强的富集锰能力。调查还发现,位于中-高锰矿区莎草生物量高达507.06g.m-2,符合超富集植物应具有较高生物量的标准。可见,莎草可作为中-高锰污染区生态修复的首先超富集植物种。     

重金属超富集植物的研究与利用

阐述了超富集植物的定义、特性及研究历史和现状,介绍了国内外应用超富集植物修复重金属污染土壤的实例,指出了超富集植物研究存在的问题和发展方向。     

超积累植物水蓼吸收锰的生理与分子机制

水蓼(Polygonum hydropiper)是一种新近发现的锰超积累植物.本文通过营养液模拟试验,研究了锰在水蓼细胞中的分布与化学形态特征,以及锰胁迫下水蓼的生理生化响应机制.结果表明:锰在水蓼叶片非活性代谢部分(细胞壁和液泡)的积累是其解毒耐锰的主要机制之一;水蓼叶片中的锰大部分以水溶性有机盐或草酸锰的形态存在;在锰浓度处理为8 000 μmol/L时,叶绿素a含量显著降低,而在其它处理条件下,叶绿素a无明显变化;在锰处理≤5000 μmol/L时水蓼叶片的细胞膜还没有受到明显伤害;水蓼叶片的可溶性蛋白含最随锰处理浓度小同而变化,说明植物在代谢和结构上发生了调整;随锰处理浓度的增加,水蓼叶片SOD和POD活性提高,保护酶活性的提高义可清除活性氧自由基,这是水蓼耐高锰和累积锰的一种生理响应机制.     

超富集植物对重金属耐受和富集机制的研究进展

超富集植物对重金属耐受和富集机制的研究成为近年来植物逆境生理研究的热点,在简要总结细胞壁沉淀、重金属螯合效应、酶活性机制和细胞区室化作用的基础上,概述了超富集植物对重金属的耐受机制,讨论了重金属跨根细胞质膜运输,共质体内运输、木质部运输和跨叶细胞膜运输的富集过程。     

水葱对镉的超富集作用及其用于植物修复的潜力

野外观察与研究发现水葱(Scirpus tabernaemontani G.)可以耐受土壤中高浓度的重金属污染,并对镉有很高的生物富集量。实验室水培试验研究了两个主要因素,营养液pH值以及镉含量,对其生物量以及镉富集效果的影响。结果表明,水葱可耐受的高浓度Cd(30mg/L)和大范围pH值变化(3.7～7.7)。当营养液pH值为4.7,Cd含量为25mg/L时,水葱富集的Cd达到最大值:地上部分264.71mg/kg,地下部分234·39mg/kg,平均转运系数1.13。这显示了它用于植物修复镉污染土壤的巨大潜力。     

植物重金属超富集机理研究进展

植物超富集重金属机理主要涉及植物对金属离子高的吸收、运输能力,区域化作用及螯合作用等方面,其中跨膜运载蛋白的表达、调控对重金属超富集这一特性起了关键作用。金属阳离子运载蛋白家族主要包括CDF家族、NRAMP家族和ZIP家族等,在超富集植物中已克隆出多个家族的金属运载蛋白基因,这些基因的过量表达对重金属在细胞中的运输、分布和富集及提高植物的抗性方面发挥了重要作用。综述了近年来研究重金属超富集植物吸收、转运和贮存Zn、Ni、Cd等重金属的生理和分子机制所取得的主要进展。     

锰毒及植物耐性机理研究进展

综述了近些年国内外关于锰毒及植物耐锰机理的研究成果,并指出了存在的问题和发展前景。锰毒是酸性土壤上限制作物产量的重要因子,国内外针对锰毒及植物耐受机制进行了相关研究,但进展较为缓慢。锰对植物的毒害效应体现在不同的细胞组织及生理生化水平上,不同植物耐受锰的机理也存在差异性,但大都集中在有机酸的螯合解毒、内部积累、外部排斥及氧化等方面。某些锰胁迫所诱导的基因也被筛选出来,并且部分生物学功能得以鉴定。此外,锰与其他营养元素间的协同或拮抗作用也得以阐述,伴随锰超富积植物-商陆在中国的发现,对锰毒及植物耐性机理的深入研究和探讨,将会对植物修复技术的开展产生理论和实践意义。     

中国镉超富集植物种类组成及分布特征研究

为丰富镉(Cd)超富集植物种质资源的筛选,促进植物修复技术研究,以现有文献报道的Cd超富集植物为基础,统计分析了Cd超富集植物的种类组成、区系分布特征及在中国的地理分布,并对后续Cd超富集植物的筛选及应用研究提出建议.结果 表明,目前已筛选出的镉超富集植物共计80种,隶属29科69属,菊科植物种类占比最大,十字花科次之...     

Nitrogen fertilizers promote plant growth and assist in manganese (Mn) accumulation by Polygonum pubescens Blume cultured in Mn tailings soil

Abstract

This study examined how different nitrogen (N) forms and application levels promote plant growth and assist in manganese (Mn) remediation of Polygonum pubescens Blume (P. pubescens) cultured in soil with a high Mn level. The effects of ammonium chloride (a) and urea (u), at three application levels (10, 20, and 30?mg L^?1 N) and control (no N addition, CK) on the growth, Mn accumulation, and enzymatic anti-oxidative defenses of P. pubescens were examined. In general, both ammonium-N and urea-N promoted the plant mass and height of P. pubescens. The total Mn amount of roots, stems, and leaves in N treatments were higher (p?<?0.05) than that of CK. The ammonium-N treatments showed greater plant biomass and Mn accumulation compared to the urea-N ones. In general, the accumulations of Mn, Cr, Zn, and Cu were significantly lower (p?<?0.05) in the N fertilizer treatment than those in the control; while the accumulations of Pb were higher (p?<?0.05) in P. pubescens across all N fertilizer treatments than those in the control. The N addition decreased the contents of O₂^? and H₂O₂ in the leaves of P. pubescens, while increasing the activities of enzymatic anti-oxidative defenses.     

超积累植物吸收重金属的根际效应研究进展

阐述近年来国内外在超积累植物吸收重金属的根际微生态效应这一领域的最新研究成果 ,介绍了根际微生态效应在植物修复中的应用 ,并对当前超积累植物在根际微生态效应研究中的不足之处和需要进一步深入研究的方向进行讨论。     

超累积植物与高生物量植物提取镉效率的比较

利用植物修复污染的土壤已受到广泛的关注.采用土壤盆栽试验,比较了超累积植物遏蓝菜与3种高生物量植物印度芥菜、烟草和向日葵对长期施用含镉有机、无机肥料污染的土壤(总Cd,2.87mg·kg-1)的提取效率.研究结果表明,遏蓝菜富集镉的能力明显高于其他3种植物,其地上部镉含量可达43.7mg·kg-1,分别是烟草、印度芥菜和向日葵(叶)的10、27和56倍;而地上部生物量最高的植物烟草,其生物量干重为24.8g· pot-1,分别是遏蓝菜、印度芥菜、向日葵的35倍、3倍、2倍.4种植物提取镉最多的是烟草,每盆可以提取117μg,遏蓝菜和印度芥菜提取镉量分别为35μg·pot-1和30μg·pot-1,向日葵提取量最少,每盆仅为10μg左右.植物对土壤中镉的提取效率分别为:烟草 1%,遏蓝菜0.6%,印度芥菜 0.5%,向日葵0.08%.4种植物种植后,土壤总镉和有效态镉含量没有显著的变化.     

Phytotoxicity of wastewater containing lead (Pb) effects scirpus grossus

Phytoremediation is an environment-friendly and cost-effective method to clean the environment of heavy metal contamination. A prolonged phytotoxicity test was conducted in a single exposure. Scirpus grossus plants were grown in sand to which the diluted Pb(NO₃)₂ was added, with the variation of concentration were 0, 100, 200, 400, 600, and 800 mg/L. It was found that Scirpus grossus plants can tolerate Pb at concentrations of up to 400 mg/L. The withering was observed on day-7 for Pb concentrations of 400 mg/L and above. 100% of the plants withered with a Pb concentration of 600 mg/L on day 65. The Pb concentration in water medium decreased while in plant tissues increased. Adsorption of Pb solution ranged between 2 to 6% for concentrations of 100 to 800 mg/L. The Bioaccumulation Coefficient and Translocation Factor of Scirpus grossus were found greater than 1, indicating that this species is a hyperaccumulator plant.     

重金属污染的植物修复及相关分子机制

随着近代工业的发展,土壤重金属污染问题日益严重。重金属即使在极低浓度下仍然可以对人畜造成健康上的威胁,因此迫切需要有效的修复方法对土壤进行修复。生物修复,特别是植物修复目前已经成为重金属污染修复的重要手段之一,了解相关植物的重金属解毒和积累分子机制是提高修复效率、解决重金属污染问题的基础。文中以土壤修复方式为起点,结合植物吸收积累重金属以及解毒的相关分子机制研究,探讨了植物修复的发展现状以及趋势。     

Development of a technology for commercial phytoextraction of nickel: economic and technical considerations

In recent R&D work, we have made progress in developing a commercial technology using hyperaccumulator plant species to phytoextract nickel (Ni) from contaminated and/or Ni-rich soils. An on-going program is being carried out to develop a genetically improved phytoextraction plant that combines favorable agronomic and Ni accumulation characteristics. Genetically diverse Ni hyperaccumulator species and ecotypes of Alyssum were collected and then evaluated in both greenhouse and field using serpentine and Ni-refinery contaminated soils. Large genetic variation was found in those studies. Mean shoot Ni concentrations in field-grown plants ranged from 4200 to 20400 mg kg^–1. We have been studying several soil management practices that may affect the efficiency of Ni phytoextraction. Soil pH is an important factor affecting absorption of metals by plants. An unexpected result of both greenhouse and field experiments was that Ni uptake by two Alyssum species was reduced at lower soil pH and increased at higher soil pH. At higher pH, plant yield was improved also. In soil fertility management studies, we found that N application significantly increased plant biomass, but did not affect plant shoot Ni concentration. These findings indicate that soil management will be important for commercial phytoextraction. A number of field trials have been carried out to study planting methods, population density, weed control practices, harvest schedule and methods, pollination control, and seed processing. Such crop management studies have improved phytoextraction efficiency and provide a tool for farmers to conduct commercial production. We have done some work to develop efficient and cost-effective methods of Ni recovery. Recovery of energy by biomass burning or pyrolysis could help make phytoextraction more cost-effective. The progress made in our recent studies will enable us to apply this technology commercially in the near future.     

植物修复──重金属污染土壤整治有效途径

系统论述了重金属污染土壤植物修复的概念、原理、方法与研究动态,列举了污染土壤植物修复的一些实例。探讨了土壤重金属超富集植物的类型、特点、应用潜力以及基因工程等现代生物技术的应用、效果与最新展望,为土壤污染的综合整治及生态修复提出了新的思路。     

Soil moisture effects on uptake of metals by Thlaspi, Alyssum, and Berkheya

Most commonly used hyperaccumulator plants for phytoextraction of metals evolved on soils where moisture is limited throughout much of the year. As these plant species are commercialized for use, they are frequently moved from the point of evolution to locations where environmental conditions may be significantly different. Greatest among these potential differences is soil moisture. The objective of this study was therefore to determine whether these plants could grow in soils with much higher soil moisture and whether they would continue to hyperaccumulate metals as soils approach saturation. We examined extractable soil metal concentrations, plant growth, and metal accumulation for the Ni hyperaccumulators, Alyssum murale and Berkheya coddii and the Zn hyperaccumulators Thlaspi caerulescens cultivars AB300 and AB336. Non-hyperaccumulating control species for each were also examined. In general, extractable soil concentrations of Ni decreased with increasing soil moisture content. Few significant effects related to Zn extractability were observed for any of the soil moisture treatments. The biomass of all tested species was generally greater at higher soil moisture and inhibited at low soil moisture. Further, plants accumulated large amounts of metals from soil at higher soil moisture. Highest foliar concentrations of Zn or Ni were found at the two highest WHCs of 80 and 100%. These results show that hyperaccumulators grow well under conditions of high soil moisture content and that they continue to hyperaccumulate metals. Thus, growing Thlaspi, Alyssum, and Berkheya for commercial phytoextraction under nonnative conditions is appropriate and suggests that this technology may be applied to a wide and diverse range of soil types, climatic conditions, and irrigation regimes.