EDTA Supported Phytoextraction of Cd from Contaminated Soil by Four Different Ornamental Plant Species

In this study, some ornamental plant species such as Althaea rosea Cavan, Lonicera japonica Thunb, Salvia virgata Jacq. (Lamiaceae), and Dahlia hybrida growing in the natural vegetation of Black Sea Region (Turkey) were investigated for their phytoextraction potential of cadmium (Cd) from artificially contaminated soil of 10, 25, 50, and 100 mg/kg concentration under pot conditions. Effect of ethylenediaminetetracetic acid (EDTA) on this removal has also been studied. To evaluate the removal efficiency of the studied plants, the bioconcentration factor (BCF) and translocation factor (TF) values were also calculated. Higher BCF and TF values obtained from stems and leaves of A. rosea Cavan, L. japonica Thunb, and S. virgata Jacq. (Lamiaceae) show that those plants might be cultivated and used as hyperaccumulators in the removal of Cd from the contaminated soils. EDTA enhanced the Cd phytoextraction in plants; however, at the same time it resulted in a slight decrease in the dry matter.     

Potential of Indigenous Plant Species for the Phytoremediation of Arsenic Contaminated Land in Kurdistan (Iran)

To evaluate the potential of the indigenous plant species for Arsenic (As) phytoremediation, a total of 138 plant samples and 138 soil samples from rooting zones were collected from two As-contaminated areas in Kurdistan, western Iran. The areas were the Sari Gunay Gold Mine (SG) and Ali Abad Village (AA). The soil of both areas naturally contains As, with mining activities at SG. Soil and plant samples were collected at five sites in the SG (SG1 to SG5) and at two sites in the AA (AA1 and AA2). Soil samples were analyzed for total and water-soluble As concentration, as well as for the main soil physical and chemical properties such as electrical conductivity (Ec), pH, organic carbon (C_org.), available phosphorus (P_ava.), and soil texture. Plant samples were analyzed for As concentration in their shoots and roots.

The average total and water–soluble As concentrations in soil were 751.6 and 6.2 ppm at SG and 920.8 and 8.0 ppm at AA, respectively. The highest root and shoot As concentration was found in Juncus inflexus (751.5 ppm) at AA2 and in Astragalus gossypinus (158.7 ppm) at AA1, respectively. With regard to phytoremediation strategies, Acantholimon brachystachyum, Astragalus gossypinus, Stipa barbata, and Ephedra major with a high translocation factor (TF) can be potentially used for As phytoextraction. However, Juncus inflexus, Phragmites australis, Bromus tomentellus, and Elymus sp., which show high bioconcentration factor (BCF) and low TF, are suggested as good candidates for As phytostabilization. In general, the TF values of terrestrial plants were higher than those of amphibious plants; meanwhile, BCF values showed the opposite behavior.     

单种及混合种植对花叶芦竹铅积累量的影响

该研究采用盆栽试验法,选取石菖蒲、水生鸢尾、美人蕉、花叶芦竹为试验材料,将石菖蒲、水生鸢尾、美人蕉与花叶芦竹混种,用花叶芦竹单种作为对照,研究了混种对花叶芦竹生物量、根冠比以及铅积累量的影响。结果表明:(1)在不同浓度铅污染处理下,与花叶芦竹单种相比,混种模式增加了花叶芦竹的根冠比,且随着铅污染浓度的增加,表现出先上升后下降的趋势。(2)在单种和混种模式下花叶芦竹体内和土壤内的铅含量均表现出明显的浓度积聚效应;在混种模式下植物体内和土壤内的铅含量明显低于单种模式,且与单种模式之间的差异性显著(P<0.05)。(3)在高浓度铅污染处理下,单种和混种模式的花叶芦竹铅转运系数均大于1,而富集系数则表现为在低浓度和高浓度铅污染处理下均大于1;在美人蕉+花叶芦竹的混种模式中,花叶芦竹的地上部分和地下部分的铅富集系数达到最大。因此,我们认为美人蕉+花叶芦竹混种模式,显著提高了花叶芦竹的生物量和根冠比,并对铅污染土壤的净化效果最佳。     

Potential of Mauritius Hemp (Furcraea gigantea Vent.) for the Remediation of Chromium Contaminated Soils

The present study was conducted to evaluate the ability of a high biomass producing, drought tolerant succulent plant Mauritius hemp (Furcraea gigantea Vent.) for its tolerance to different levels of Cr (0, 25, 50, 100 and 200 mg Cr kg soil^?1) and its potential for phytoremediation purposes. Based on the data on inhibition of the growth of plants with Cr, tolerance index and grade of growth inhibition, it was observed that the plant could tolerate up to 50 mg Cr kg ^?1 soil. Absorption of Cr from soil to plant and its translocation into plant tissues were discussed in terms of bio concentration factor (BCF), transfer factor (TF), and translocation efficiency (TE%). Cr was mainly accumulated in the roots and exclusion of Cr was found to be the principal physiological tolerance mechanism followed by a marked increase in proline, ascorbic acid, total free amino acids in the leaf tissue and malic acid in the rhizosphere samples to counter Cr stress. Based on the tissue concentration of Cr (< 300 μg g^?1 in the leaves and TF<1), it was concluded that, Furcraea gigantea could not be considered a hyperaccumulator and therefore unsuitable for phytoextraction of Cr. Nevertheless, Furcraea gigantea could be a suitable candidate for phytostablization of Cr contaminated soils.     

Involvement of Asada-Halliwell Pathway During Phytoremediation of Chromium (VI) in Brassica juncea L. Plants

Brassica juncea (Indian mustard) L. plants were exposed to different concentrations (0.0, 0.1, 0.3 and 0.5 mM) of Chromium (Cr) and harvested after 30 and 60 days of sowing for the analysis of growth parameters, metal uptake and oxidative stress markers. Significant accumulation of Cr (VI) by B. juncea L. plants resulted in the reduced growth and modulations in the pool of various biochemical stress markers. The toxic effects of Cr (VI) on growth and other stress markers (protein content, lipid peroxidation and antioxidative enzymes viz.SOD, CAT, POD, APOX, GR, DHAR and MDHAR) in B. juncea L. were observed to be concentration and time dependent. Effect of Cr (VI) on biochemical parameters was differential and their maximum activities of SOD, POD, APX, GR, DHAR and lipid peroxidation were recorded at 0.5 mM concentration in 30 days old plants. Whereas, trend in the activities of most of the stress markers was reversed in 60 days old plants. The results obtained from the study suggested that Cr (VI) stress inhibited growth of B. juncea L. plants is directly interrelated with its accumulation and resulted in the modulation in activities of various stress markers.     

Phytoremedial Potential of Typha latifolia,Eichornia crassipes and Monochoria hastata found in Contaminated Water Bodies Across Ranchi City (India)

Phytoremediation is an emerging technology that uses green plants (living machines) for removal of contaminants of concern (COC). These plant species have the potential to remove the COC, thereby restoring the original condition of soil or water environment. The present study focuses on assessing the heavy metals (COC) present in the contaminated water bodies of Ranchi city, Jharkhand, India. Phytoremedial potential of three plant species: Typha latifolia, Eichornia crassipes and Monochoria hastata were assessed in the present study. Heterogenous accumulation of metals was found in the three plant species. It was observed that the ratio of heavy metal concentration was different in different parts, i.e., shoots and roots. Positive results were also obtained for translocation factor of all species with minimum of 0.10 and maximum of 1. It was found experimentally that M. hastata has the maximum BFC for root as 4.32 and shoot as 2.70 (for Manganese). For T. latifolia, BCF of maximum was observed for root (163.5) and respective shoot 86.46 (for Iron), followed by 7.3 and 5.8 for root and shoot (for Manganese) respectively. E. crassipes was found to possess a maximum BCF of 278.6 (for Manganese and 151 (for Iron) and shoot as 142 (for Manganese) and 36.13 (for Iron).     

Effects of lead and cadmium on photosynthesis in Amaranthus spinosus and assessment of phytoremediation potential

Abstract

This study assessed the effects of Pb (0, 200, 500, 1000?mg kg^?1) and Cd (0, 5, 15, 30, 50?mg kg^?1) on photosynthesis in Amaranthus spinosus (A. spinosus), as well as the potential for phytoremediation by pot-culture experiment. Exposure to Pb/Cd produced a concentration-dependent decrease in biomass and all photosynthesis parameters, except for non-photochemical quenching, which increased with the metal concentration. The metals accumulated more in roots compared to shoots. The bioconcentration factor (BCF) of Pb was <1 in shoots at all Pb levels, whereas the BCF was <1 in roots at all but the lowest concentration of Pb. Roots extracted Cd from soil at all treatments. The translocation factor of Cd was larger than that of Pb suggesting that Cd is more mobile than Pb in A. spinosus. Amaranthus spinosus displays a high tolerance for both Pb and Cd with regards to growth and photochemical efficiency, but it is more sensitive to Cd than Pb. Amaranthus spinosus accumulates Pb and Cd primarily in the roots and Cd is more bioconcentrated and translocated in comparison to Pb. This investigation shows that A. spinosus has good potential for phytoremediation of soils contaminated by low levels of Cd and Pb.     

Screening of Indigenous Ornamental Species from Different Plant Families for Pb Accumulation Potential Exposed to Metal Gradient in Spiked Soils

Contamination of surface soils with lead (Pb) is a global concern due to the release of hazardous materials containing the metal element. In order to explore ways to remediate contaminated soils with less impact on environment and costs, this study aimed at screening ornamental plant species exposed to Pb gradient in spiked soils for Pb phytoextraction. Twenty-one ornamental plant species that currently grow in Pakistan, were selected to assess their potential for Pb accumulation. Pot experiments were conducted to evaluate the accumulative properties of the different plant species in unspiked control (Pb = 0) and spiked soils with different levels of Pb at 500, 1000, 1500 and 2000 mg Pb kg^?1 of soil. Biotranslocation factor (TF), Enrichment factor (EF) and Bioconcentration factor (CF) were calculated to assess the phytoremediation potential of tested plant species after seven weeks of exposure. Out of 21 plant species, Pelargonium hortorum and Mesembryanthemum criniflorum performed better and accumulated more than 1000 mg Pb kg^?1 of shoot dry biomass when they were grown in 500, 1000 and 1500 mg Pb kg^?1 contaminated soils. Both plants had no significant (P < 0.05) variation in the total dry biomass with increasing soil Pb concentration indicating a high tolerance to Pb. Considering the capacity of Pb accumulation, total dry biomass, TF, EF &; CF indices, Pelargonium hortorum and Mesembryanthemum criniflorum could be considered as Pb hyperaccumulators and could have the potential to be used in phytoremediation.     

樱桃砧木实生苗对根癌菌侵染的抗性及生理响应

以贵州樱桃的6个砧木实生苗为材料,采用人工接种根癌菌的方法,探讨它们对根癌菌侵染的抗性及生理响应特征,评价其抗病性能力。结果显示:(1)接种根癌菌120d后,青岩樱桃实生苗发病率较低(6.67%),冠瘿瘤直径较小(1.76mm),感病系数也较低(6.67),属高抗砧木;沿河樱桃实生苗发病率高达50.0%,冠瘿瘤直径达6.43mm,感病系数达33.76,属高感砧木。(2)感染根癌菌后,各樱桃砧木幼苗的生理特性受到一定影响,其叶片游离脯氨酸含量增加,根系过氧化物酶(POD)和超氧化物歧化酶(SOD)活性增强,而过氧化氢酶(CAT)活性降低,其中,青岩樱桃的游离脯氨酸含量升高幅度最大,沿河樱桃的保护酶活性变化幅度明显较大。(3)樱桃砧木幼苗的发病率与感病系数呈显著正相关(0.98*);发病率与SOD活性、感病系数与POD活性和SOD活性均呈显著正相关,相关系数分别为0.86、0.82、0.83;其余指标间相关性不显著。研究表明,6个樱桃砧木实生苗对根癌菌的抗性有明显差异,并以青岩樱桃最强,且其抗性强弱与其感病后叶片脯氨酸含量和根系的POD、SOD活性增加幅度有密切关系。     

The ability of Silybum marianum to phytoremediate cadmium and/or diesel oil from the soil

Phytoremediation is a new ecological and cost-effective technology applied for cleaning heavy metals and total petroleum hydrocarbon contaminated (TPH-contaminated) soils. This study was conducted to evaluate the potential of milk thistle (Silybum marianum) to phytoremediate cadmium (Cd (II)) from contaminated soils. To this end, the investigators applied a completely randomized design with the factorial arrangement and four replications. The results indicated that all the evaluated parameters of S. Marianum, including shoot and root fresh and dry weight, as well as shoot and root Cd, were significantly influenced by Cd (II) concentration and diesel oil (DO). The Cd-contaminated soil showed minor declining effects on the produced plant biomass, whereas the DO-contaminated soil had more inhibitory effects. Moreover, the soil contaminated with both Cd and DO led to adverse effects on the plant biomass. The shoot and root Cd concentration had an increasing trend in the presence of DO as the bioconcentration factor (BCF) by 1.740 (+90.78%), 1.410 (+36.89%), 2.050 (+31.41%), 1.68 (+32.28%), and 1.371 (+22.41%) compared to the soil without DO at Cd (II) concentrations of 20, 40, 60, 80, and 100 mg/kg, respectively. Biological accumulation coefficient also showed the same trend as the BCF. In all the treatments, the translocation factor was >1. Therefore, it was demonstrated that milk thistle had high potential for transferring Cd from root to shoot and reducing its concentration in the soil. Moreover, the study revealed that milk thistle had high potential for absorbing Cd in the soil contaminated with Cd and DO.     

Metal-Dependent Root Iron Plaque Effects on Distribution and Translocation of Chromium and Nickel in Yellow Flag (Iris pseudacorus L.)

Iris pseudacorus L. (yellow flag) is a wide-use wetland plant for constructed wetlands for removing metals from wastewater. This study aims to understand effects of root iron plaque on sequestration and translocation of Cr and Ni in yellow flag seedlings using a hydroponic experiment. Yellow flag seedlings (4-week-old seedlings with 4–6 leaves) with or without iron plaque induction (at 50 mg Fe²⁺ L^?1 for 72 hours) were spiked for 6 days in the Hoagland solution with Cr or Ni at 0.5, 5, and 50 mg L^?1, equivalent to 1, 10, 100 times of thresholds of surface water quality, respectively. Results indicated that root iron plaque significantly reduced translocation of Cr and Ni to root but increased from root to shoot. Root iron plaque formation counteracted Cr toxicity to yellow flag seedlings while the control showed Cr toxicity to root at 5 mg L^?1and to shoot at 50 mg L^?1 with significant biomass loss. Neither Ni exposures caused significant biomass loss nor root iron plaque formation significantly changed Ni distribution among plant parts. Our study suggests that root iron plaque effects on metal sequestration and translocation in yellow flag seedlings were metal-dependent.     

Growth and bioaccumulation characteristics of watercress (Nasturtium officinale R. BR.) exposed to cadmium,cobalt and chromium

Abstract

The aim of this study is to determine the effects of Cd, Co and Cr on the growth of watercress (Nasturtium officinale) and to determine the bioaccumulation properties of these heavy metals by the plant. N. officinale individuals were exposed to different concentrations of Cd, Co and Cr for 72 h. Relative growth rates (RGR) and bioconcentration factor (BCF) ratios were calculated for each metal concentration. RGR values of plants exposed to Co slightly increased in lower concentrations, but then decreased again. In contrast, RGR values of plants exposed to Cd and Cr decreased linearly. Significant positive relationships were observed among the concentrations of Cd, Co and Cr in N. officinale and in the culture solution. BCF ratios were highest for plants exposed to Co, and lowest for plants exposed to Cr. The most efficient uptake of Cd, Co and Cr occurred at the external solution concentrations at 0.5, 0.5 and 10 mM, respectively.     

Kinetics of Cr(III) and Cr(VI) removal from water by two floating macrophytes

The aim of this work was to compare Cr(III) and Cr(VI) removal kinetics from water by Pistia stratiotes and Salvinia herzogii. The accumulation in plant tissues and the effects of both Cr forms on plant growth were also evaluated. Plants were exposed to 2 and 6 mg L^?1 of Cr(III) or Cr(VI) during 30 days. At the end of the experiment, Cr(VI) removal percentages were significantly lower than those obtained for Cr(III) for both macrophytes. Cr(III) removal kinetics involved a fast and a slow component. The fast component was primarily responsible for Cr(III) removal while Cr(VI) removal kinetics involved only a slow process. Cr accumulated principally in the roots. In the Cr(VI) treatments a higher translocation from roots to aerial parts than in Cr(III) treatments was observed. Both macrophytes demonstrated a high ability to remove Cr(III) but not Cr(VI). Cr(III) inhibited the growth at the highest studied concentration of both macrophytes while Cr(VI) caused senescence. These results have important implications in the use of constructed wetlands for secondary industrial wastewater treatment. Common primary treatments of effluents containing Cr(VI) consists in its reduction to Cr(III). Cr(III) concentrations in these effluents are normally below the highest studied concentrations in this work.     

Mercury uptake and phytotoxicity in terrestrial plants grown naturally in the Gumuskoy (Kutahya) mining area,Turkey

This study investigated mercury (Hg) uptake and transport from the soil to different plant parts by documenting the distribution and accumulation of Hg in the roots and shoots of 12 terrestrial plant species, all of which grow naturally in surface soils of the Gumuskoy Pb-Ag mining area. Plant samples and their associated soils were collected and analyzed for Hg content by ICP-MS. Mean Hg values in the soils, roots, and shoots of all plants were 6.914, 460, and 206 µg kg^?1, respectively and lower than 1. The mean enrichment factors for the roots (ECR) and shoots (ECS) of these plants were 0.06 and 0.09, respectively and lower than 1. These results show that the roots of the studied plants prevented Hg from reaching the aerial parts of the plants. The mean translocation factor (TLF) was 1.29 and higher than 1. The mean TLF values indicated that all 12 plant species had the ability to transfer Hg from the roots to the shoots but that transfer was more efficient in plants with higher ECR and ECS. Therefore, these plants could be useful for the biomonitoring of environmental pollution and for rehabilitating areas contaminated by Hg.     

Use of bacterial acc deaminase to increase oil (especially poly aromatic hydrocarbons) phytoremediation efficiency for maize (zea mays) seedlings

Oil presence in soil, as a stressor, reduces phytoremediation efficiency through an increase in the plant stress ethylene. Bacterial 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, as a plant stress ethylene reducer, was employed to increase oil phytoremediation efficiency. For this purpose, the ability of ACC deaminase-producing Pseudomonas strains to grow in oil-polluted culture media and withstand various concentrations of oil and also their ability to reduce plant stress ethylene and enhance some growth characteristics of maize and finally their effects on increasing phytoremediation efficiency of poly aromatic hydrocarbons (PAHs) in soil were investigated. Based on the results, of tested strains just P9 and P12 were able to perform oil degradation. Increasing oil concentration from 0 to 10% augmented these two strains population, 15.7% and 12.9%, respectively. The maximum increase in maize growth was observed in presence of P12 strain. Results of high-performance liquid chromatography (HPLC) revealed that PAHs phytoremediation efficiency was higher for inoculated seeds than uninoculated. The highest plant growth and PAHs removal percentage (74.9%) from oil-polluted soil was observed in maize inoculated with P12. These results indicate the significance of ACC deaminase producing bacteria in alleviation of plant stress ethylene in oil-polluted soils and increasing phytoremediation efficiency of such soils.     

Metal Tolerance and Accumulation Ability of the Ni Hyperaccumulator Streptanthus polygaloides Gray (Brassicaceae)

High concentrations of metals occur in some plant species (termed hyperaccumulators), such as the Ni hyperaccumulator Streptanthus polygaloides. We determined the tolerance of S. polygaloides to, and its accumulation abilities for, six metals (Ni, Zn, Cu, Co, Mn, and Pb). Potting mix concentrations used for all metals ranged from 0 to 1200 μg/g dry weight. For Ni, a treatment of 1600 μg/g was included. For Mn, treatments of 1600, 2000, and 2500 μg/g also were used, and for Pb these concentrations plus 3500 μg/g were included. Germination, plant number per pot, and size at days 30 and 39, number of plants at the end of the experiment (day 49), flower production, and metal concentration in the aboveground biomass were documented. Lead and Ni showed no consistent effects on plant performance, but yielded increased tissue metal concentrations. Streptanthus polygaloides was more sensitive to Co, Cu, and Zn, as ≥ 400 mg/g significantly suppressed plant growth, survival, and flower production. Tissue metal concentrations also were increased to maxima of 1500 μg Co/g, 120 μg Cu/g, and 6000 μg Zn/g. Manganese affected S. polygaloides less markedly, as ≥ 800 mg/kg decreased growth, survival, and flower production. Maximum tissue Mn concentration was 2900 μg/g. We concluded that S. polygaloides would be an appropriate phytoextractor for soils contaminated with Ni or low levels of Co but would not be useful for Cu, Zn, Mn, and Pb.     

Chromium (III) enhanced diamine silver staining of proteins and DNA in gels

Chromium (III) enhanced the sensitivities of diamine silver staining of four proteins between 6- and 50-fold over that of the Coomassie Brilliant Blue (CBB)-chromium modified thiosulfate-silver staining method (Zhou et al. Biotechnology Letters, 2002, 24: 1561–1567). Using six dsDNA fragments, the detection limits of this new method was 10 to 30 pg per band, being 10- to 25-fold more sensitive than previous methods.     

Heterologous Expression of a Mammalian ABC Transporter in Plant and its Application to Phytoremediation

Mammalian ATP-binding cassette (ABC) transporters involved in the multidrug-resistance of cancer cells can efflux cytotoxic compounds that show a wide variety of chemical structures and biological activities. Human multidrug resistance-associated protein (hMRP1) is one of the most intensively studied ABC transporters and many substrates have been identified, including both organic and inorganic compounds. In an attempt at novel ‘transport engineering’ using hMRP1 as a molecular pump, we established transgenic tobacco plants that showed clear resistance to cadmium and daunorubicin, although they were not resistant to etoposide, another known substrate of hMRP1. When expressed in tobacco cells, hMRP1 protein was localized at vacuolar membrane, while members of the MRP family are localized at plasma membrane in mammalian cells to reduce the cellular accumulation of various drugs. Thus, the hMRP1-expressing tobacco cells were able to take up these substrates across the tonoplast and sequestrate them in the vacuolar matrix. These results suggest that it may be possible to use the transgenic tobacco in phytoremediation, where a single transformation with an ABC transporter with broad substrate specificity should be effective for extracting various environmental pollutants including both organic and inorganic compounds, and accumulate them in the plant body. This should be advantageous for the remediation of a complex polluted environment, which is commonly found in the real world. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users. An erratum to this article is available at .     

Susceptibility of Riparian Wetland Plants to Perfluorooctanoic Acid (PFOA) Accumulation

As plants have been shown to accumulate organic compounds from contaminated sediments, there is a potential for long-lasting ecological impact as a result of contaminant accumulation in riparian areas of wetlands, particularly the accumulation of non-biodegradable contaminants such as perfluorooctanoic acid (PFOA). In this study, commonly found riparian wetland plants including reeds, i.e., Xanthium strumarium, Phragmites australis, Schoenoplectus corymbosus, Ruppia maritime; Populus canescens, Polygonum salicifolium, Cyperus congestus; Persicaria amphibian, Ficus carica, Artemisia schmidtiana, Eichhornia crassipes, were studied to determine their susceptibility to PFOA accumulation from PFOA contaminated riparian sediment with a known PFOA concentration, using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The bioconcentration factor (BCF) indicated that the plants affinity to PFOA accumulation was; E. crassipes, > P. salicifolium, > C. congestus, > P. x canescens, > P. amphibian, > F. carica, > A. schmidtiana, > X. strumarium, > P. australis, > R. maritime, > S. corymbosus. The concentration of PFOA in the plants and/or reeds was in the range 11.7 to 38 ng/g, with a BCF range of 0.05 to 0.37. The highest BCF was observed in sediment for which its core water had a high salinity, total organic carbon and a pH which was near neutral. As the studied plants had a higher affinity for PFOA, the resultant effect is that riparian plants such as E. crassipes, X. strumarium, and P. salicifolium, typified by a fibrous rooting system, which grow closer to the water edge, exacerbate the accumulation of PFOA in riparian wetlands.