Mass-flow modeling of engineered nanomaterials (ENMs) indicates that a major fraction of released particles partition into soils and sediments. This has aggravated the risk of contaminating agricultural fields, potentially threatening... more
Mass-flow modeling of engineered nanomaterials (ENMs) indicates that a major fraction of released particles partition into soils and sediments. This has aggravated the risk of contaminating agricultural fields, potentially threatening associated food webs. To assess possible ENM trophic transfer, cerium accumulation from cerium oxide nanoparticles (nano-CeO2) and their bulk equivalent (bulk-CeO2) was investigated in producers and consumers from a terrestrial food chain. Kidney bean plants (Phaseolus vulgaris var. red hawk) grown in soil contaminated with 1000-2000 mg/kg nano-CeO2 or 1000 mg/kg bulk-CeO2 were presented to Mexican bean beetles (Epilachna varivestis), which were then consumed by spined soldier bugs (Podisus maculiventris). Cerium accumulation in plant and insects was independent of particle size. After 36 days of exposure to 1000 mg/kg nano- and bulk-CeO2, roots accumulated 26 and 19 μg/g Ce, respectively, and translocated 1.02 and 1.3 μg/g Ce, respectively, to shoots....
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Little is known about the physiological and biochemical responses of plants exposed to surface modified nanomaterials. In this study, tomato (Solanum lycopersicum L.) plants were cultivated for 210days in potting soil amended with... more
Little is known about the physiological and biochemical responses of plants exposed to surface modified nanomaterials. In this study, tomato (Solanum lycopersicum L.) plants were cultivated for 210days in potting soil amended with uncoated and citric acid coated cerium oxide nanoparticles (nCeO2, CA+nCeO2) bulk cerium oxide (bCeO2), and cerium acetate (CeAc). Millipore water (MPW), and citric acid (CA) were used as controls. Physiological and biochemical parameters were measured. At 500mg/kg, both the uncoated and CA+nCeO2 increased shoot length by ~9 and ~13%, respectively, while bCeO2 and CeAc decreased shoot length by ~48 and ~26%, respectively, compared with MPW (p≤0.05). Total chlorophyll, chlo-a, and chlo-b were significantly increased by CA+nCeO2 at 250mg/kg, but reduced by bCeO2 at 62.5mg/kg, compared with MPW. At 250 and 500mg/kg, nCeO2 increased Ce in roots by 10 and 7 times, compared to CA+nCeO2, but none of the treatments affected the Ce concentration in above ground tissues. Neither nCeO2 nor CA+nCeO2 affected the homeostasis of nutrient elements in roots, stems, and leaves or catalase and ascorbate peroxidase in leaves. CeAc at 62.5 and 125mg/kg increased B (81%) and Fe (174%) in roots, while at 250 and 500mg/kg, increased Ca in stems (84% and 86%, respectively). On the other hand, bCeO2 at 62.5 increased Zn (152%) but reduced P (80%) in stems. Only nCeO2 at 62.5mg/kg produced higher total number of tomatoes, compared with control and the rest of the treatments. The surface coating reduced Ce uptake by roots but did not affect its translocation to the aboveground organs. In addition, there was no clear effect of surface coating on fruit production. To our knowledge, this is the first study comparing the effects of coated and uncoated nCeO2 on tomato plants.
The rapidly growing literature on the response of edible plants to nanoceria has provided evidence of its uptake and bioaccumulation, which delineates a possible route of entry into the food chain. However, little is known about how the... more
The rapidly growing literature on the response of edible plants to nanoceria has provided evidence of its uptake and bioaccumulation, which delineates a possible route of entry into the food chain. However, little is known about how the residing organic matter in soil may affect the bioavailability and resulting impacts of nanoceria on plants. Here, we examined the effect of nanoceria exposure (62.5-500 mg/kg) on kidney bean (Phaseolus vulgaris) productivity and seed quality as a function of soil organic matter content. Cerium accumulation in the seeds produced from plants in organic matter enriched soil showed a dose-dependent increase, unlike in low organic matter soil treatments. Seeds obtained upon nanoceria exposure in soils with higher organic matter were more susceptible to changes in nutrient quality. A quantitative proteomic analysis of the seeds produced upon nanoceria exposure provided evidence for upregulation of stress-related proteins at 62.5 and 125 mg/kg nanoceria tr...
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The rapidly growing literature on the response of edible plants to nanoceria has provided evidence of its uptake and bioaccumulation, which delineates a possible route of entry into the food chain. However, little is known about how the... more
The rapidly growing literature on the response of edible plants to nanoceria has provided evidence of its uptake and bioaccumulation, which delineates a possible route of entry into the food chain. However, little is known about how the residing organic matter in soil may affect the bioavailability and resulting impacts of nanoceria on plants. Here, we examined the effect of nanoceria exposure (62.5-500 mg/kg) on kidney bean (Phaseolus vulgaris) productivity and seed quality as a function of soil organic matter content. Cerium accumulation in the seeds produced from plants in organic matter enriched soil showed a dose-dependent increase, unlike in low organic matter soil treatments. Seeds obtained upon nanoceria exposure in soils with higher organic matter were more susceptible to changes in nutrient quality. A quantitative proteomic analysis of the seeds produced upon nanoceria exposure provided evidence for upregulation of stress-related proteins at 62.5 and 125 mg/kg nanoceria tr...
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Interactions of nCeO2 with plants have been mostly evaluated at seedling stage and under controlled conditions. In this study, the effects of nCeO2 at 0 (control), 100 (low), and 400 (high) mg/kg were monitored for the entire life cycle... more
Interactions of nCeO2 with plants have been mostly evaluated at seedling stage and under controlled conditions. In this study, the effects of nCeO2 at 0 (control), 100 (low), and 400 (high) mg/kg were monitored for the entire life cycle (about 7 months) of wheat plants grown in a field lysimeter. Results showed that at high concentration nCeO2 decreased the chlorophyll content and increased catalase and superoxide dismutase activities, compared with control. Both concentrations changed root and leaf cell microstructures by agglomerating chromatin in nuclei, delaying flowering by 1 week, and reduced the size of starch grains in endosperm. Exposed to low concentration produced embryos with larger vacuoles, while exposure to high concentration reduced number of vacuoles, compared with control. There were no effects on the final biomass and yield, Ce concentration in shoots, as well as sugar and starch contents in grains, but grain protein increased by 24.8% and 32.6% at 100 and 400 mg/...
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Interactions of nCeO2 with plants have been mostly evaluated at seedling stage and under controlled conditions. In this study, the effects of nCeO2 at 0 (control), 100 (low), and 400 (high) mg/kg were monitored for the entire life cycle... more
Interactions of nCeO2 with plants have been mostly evaluated at seedling stage and under controlled conditions. In this study, the effects of nCeO2 at 0 (control), 100 (low), and 400 (high) mg/kg were monitored for the entire life cycle (about 7 months) of wheat plants grown in a field lysimeter. Results showed that at high concentration nCeO2 decreased the chlorophyll content and increased catalase and superoxide dismutase activities, compared with control. Both concentrations changed root and leaf cell microstructures by agglomerating chromatin in nuclei, delaying flowering by 1 week, and reduced the size of starch grains in endosperm. Exposed to low concentration produced embryos with larger vacuoles, while exposure to high concentration reduced number of vacuoles, compared with control. There were no effects on the final biomass and yield, Ce concentration in shoots, as well as sugar and starch contents in grains, but grain protein increased by 24.8% and 32.6% at 100 and 400 mg/...
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Tumbleweed plants (S. kali) accumulate considerable amounts of Pb, Cd and Cr in their tissues. Moreover, this plant has been proposed as a potential Cd hyperaccumulator. In order to obtain a more complete profile for metal accumulation... more
Tumbleweed plants (S. kali) accumulate considerable amounts of Pb, Cd and Cr in their tissues. Moreover, this plant has been proposed as a potential Cd hyperaccumulator. In order to obtain a more complete profile for metal accumulation and tolerance, experiments were conducted in agar media individually contaminated with 0-40 mg L−1 of Cu(II), Ni(II), and Zn(II). Zn was rather beneficial as it promoted root and shoot elongation as well as biomass accumulation. Plants exposed to Cu accumulated 1300 mg kg−1 dry weight in the aerial plant part, indicating a potential hyperaccumulation. X-ray absorption spectroscopic (XAS) studies showed that tumbleweed plants absorb and move Zn and Ni from the roots to the leaves without changes in oxidation state and coordination environment; however, Cu is transported to the aerial part probably bound to different compounds in different plant tissues. Oxygen/nitrogen were identified as ligands for Zn; Cu was observed complexed to sulfur and oxygen, w...
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Tumbleweed plants (S. kali) accumulate considerable amounts of Pb, Cd and Cr in their tissues. Moreover, this plant has been proposed as a potential Cd hyperaccumulator. In order to obtain a more complete profile for metal accumulation... more
Tumbleweed plants (S. kali) accumulate considerable amounts of Pb, Cd and Cr in their tissues. Moreover, this plant has been proposed as a potential Cd hyperaccumulator. In order to obtain a more complete profile for metal accumulation and tolerance, experiments were conducted in agar media individually contaminated with 0-40 mg L−1 of Cu(II), Ni(II), and Zn(II). Zn was rather beneficial as it promoted root and shoot elongation as well as biomass accumulation. Plants exposed to Cu accumulated 1300 mg kg−1 dry weight in the aerial plant part, indicating a potential hyperaccumulation. X-ray absorption spectroscopic (XAS) studies showed that tumbleweed plants absorb and move Zn and Ni from the roots to the leaves without changes in oxidation state and coordination environment; however, Cu is transported to the aerial part probably bound to different compounds in different plant tissues. Oxygen/nitrogen were identified as ligands for Zn; Cu was observed complexed to sulfur and oxygen, w...
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Cerium oxide nanoparticles (NPs) or nanoceria have a high level of UV absorption and antioxidant behavior, making them great candidates for sun screens, beauty products, and cancer and glaucoma treatments. The increased use of these NPs... more
Cerium oxide nanoparticles (NPs) or nanoceria have a high level of UV absorption and antioxidant behavior, making them great candidates for sun screens, beauty products, and cancer and glaucoma treatments. The increased use of these NPs underscores the importance of understanding their environmental fate and toxicity. So far, information about nanoceria toxicity to plants is scarce. The objectives of this study are to determine the effect of CeO2 NPs on soybean (Glycine max) plant growth and monitor their uptake, deposition, and biotransformation. Soybean plants were treated for 14 days in a modified Hoagland solution containing varying concentrations of CeO2 NPs (0, 500, 1000, 2000, and 4000 mg/L). Leaves, stems, and roots of the treated soybean plants were analyzed separately using ICP-OES and XAS. The ICP-OES results showed cerium concentrations in roots varying from 37068 - 74774 mg kg-1. In stems and leaves there was a maximum cerium concentration of 3028 and 1048 mg kg-1, resp...
Cerium oxide nanoparticles (NPs) or nanoceria have a high level of UV absorption and antioxidant behavior, making them great candidates for sun screens, beauty products, and cancer and glaucoma treatments. The increased use of these NPs... more
Cerium oxide nanoparticles (NPs) or nanoceria have a high level of UV absorption and antioxidant behavior, making them great candidates for sun screens, beauty products, and cancer and glaucoma treatments. The increased use of these NPs underscores the importance of understanding their environmental fate and toxicity. So far, information about nanoceria toxicity to plants is scarce. The objectives of this study are to determine the effect of CeO2 NPs on soybean (Glycine max) plant growth and monitor their uptake, deposition, and biotransformation. Soybean plants were treated for 14 days in a modified Hoagland solution containing varying concentrations of CeO2 NPs (0, 500, 1000, 2000, and 4000 mg/L). Leaves, stems, and roots of the treated soybean plants were analyzed separately using ICP-OES and XAS. The ICP-OES results showed cerium concentrations in roots varying from 37068 - 74774 mg kg-1. In stems and leaves there was a maximum cerium concentration of 3028 and 1048 mg kg-1, resp...
Cerium oxide nanoparticles (nCeO2) have extensive industrial applications, and concerns regarding their threat to the environment have been raised. This study includes structural analysis of intact root xylem of rice (Oryza sativa L.),... more
Cerium oxide nanoparticles (nCeO2) have extensive industrial applications, and concerns regarding their threat to the environment have been raised. This study includes structural analysis of intact root xylem of rice (Oryza sativa L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) seedlings exposed to nCeO2 suspensions (0, 62.5, 125, 250, and 500 mg L(-1)). Fourier transform infrared microspectroscopy was applied to determine compositional alterations in the root xylem, and principal component analysis (PCA) was carried out to examine spectral differences between nCeO2 treatments. Results demonstrated that nCeO2 at 125 mg L(-1) changed the region of spectra around 1696-1760 cm(-1) in rice root, 125 and 250 mg L(-1) modified 1744-1792 cm(-1) in wheat, and 62.5 and 125 mg L(-1) altered 1727-1760 cm(-1) in barley. PCA afforded the clustering of nCeO2 treatments at 0 and 62.5 mg L(-1) in rice and wheat and 0 and 500 mg L(-1) in barley. Furthermore, major peaks at 1744 or...
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Environmental matrices including soils, sediments, and living organisms are reservoirs of several essential as well as non-essential elements. Accurate qualitative and quantitative information on the distribution and interaction of... more
Environmental matrices including soils, sediments, and living organisms are reservoirs of several essential as well as non-essential elements. Accurate qualitative and quantitative information on the distribution and interaction of biologically significant elements is vital to understand the role of these elements in environmental and biological samples. Synchrotron micro-X-ray fluorescence (μ-SXRF) allows in situ mapping of biologically important elements at nanometer to sub-micrometer scale with high sensitivity, negligible sample damage and enable tuning of the incident energy as desired. Beamlines in the synchrotron facilities are rapidly increasing their analytical versatility in terms of focusing optics, detector technologies, incident energy, and sample environment. Although extremely competitive, it is now feasible to find stations offering complimentary techniques like micro-X-ray diffraction (μ-XRD) and micro-X-ray absorption spectroscopy (μ-XAS) that will allow a more com...
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Our main objective was to study the possible toxicity of engineered ZnO nanoparticles (NPs), and Zn+2 ions on seed germination and root elongation in alfalfa (Medicago sativa). Alfalfa seeds were germinated in 0, 50, 100, 200, 400, 800,... more
Our main objective was to study the possible toxicity of engineered ZnO nanoparticles (NPs), and Zn+2 ions on seed germination and root elongation in alfalfa (Medicago sativa). Alfalfa seeds were germinated in 0, 50, 100, 200, 400, 800, and 1600 mg/L of ZnO NPs and in 0, 0.05, 0.5, 5.0, 10, 50 and 250 mg/L of Zn(NO3)2. The data showed a 40% reduction in seed germination at 800 and 1600 mg/L of ZnO NPs and at 50 and 250 mg/L of Zn(NO3)2. Inhibitory concentration of 50% (IC50) was observed at 800 and 1600 mg/L of ZnO NPs and at 250 mg/L of Zn(NO3)2 .Alfalfa root growth significantly decreased at 50 mg/L of Zn(NO3)2. Seedlings treated with 1600 mg/L of ZnO NPs had 4,700 mg Zn kg-1 dry weight (DW). While seedlings treated with 250 mg/L of Zn(NO3)2 had about 3500 mg Zn kg-1 DW.
... 43] and [44]. Furthermore, phytoremediation does not generate sludge and metals accumulated by plants can be recovered by metal extraction processes and incineration. 3.1. Heavy metal toxicity to plants. One of the disadvantages ...
Research Interests: Inorganic Chemistry, Coordination Chemistry, Speciation, X ray absorption spectroscopy, Aquatic Plants, and 16 morePopulus, Copper, EXAFS, Heavy Metal, Zinc, Nickel, Contaminated soil, XANES, Brassica juncea, Eichhornia crassipes, Xas, Cancer Cell, Silver Nanoparticle, Aqueous Solution, Pilot project, and Phytoextraction
The implications of engineered nanomaterials on crop productivity and food quality are not yet well understood. The impacts of cerium oxide nanoparticles (nCeO2) on growth and yield attributes and nutritional composition in wheat... more
The implications of engineered nanomaterials on crop productivity and food quality are not yet well understood. The impacts of cerium oxide nanoparticles (nCeO2) on growth and yield attributes and nutritional composition in wheat (Triticum aestivum L.) were examined. Wheat was cultivated to grain production in soil amended with 0, 125, 250, and 500 mg nCeO2/kg (control, nCeO2-L, nCeO2-M, and nCeO2-H, respectively). At harvest, grains and tissues were analyzed for mineral, fatty acids, and amino acids contents. Results showed that, relative to the control, nCeO2-H improved plant growth, shoot biomass, and grain yield by 9.0, 12.7, and 36.6%, respectively. Ce accumulation in roots increased at increased nCeO2 concentration but did not change across treatments in leaves, hull and grains indicating a lack of Ce transport to the aboveground tissues. nCeO2 modified the S and Mn storage in grains. nCeO2-L modified the amino acids composition, and increased the linolenic acid by up to 6.17%...
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Phytoremediation is a novel cleanup technology for the removal of contaminants from polluted waters and soils. In phytoremediation, the plant uptake capability and the availability of the pollutant in the media are important. Here we show... more
Phytoremediation is a novel cleanup technology for the removal of contaminants from polluted waters and soils. In phytoremediation, the plant uptake capability and the availability of the pollutant in the media are important. Here we show the results of a study on the combined effects of ethylenediaminetetraacetic acid (EDTA) and the phytohormone indole-3-acetic acid (IAA) on Pb uptake by Medicago sativa (alfalfa). Plants were grown in hydroponics media containing a nutrient solution amended with Pb at 0.2mM and different combinations of EDTA, and IAA. After 10d of treatment, the Pb content in plant tissues was quantified using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP/OES). The results showed that the combination of 100 microM IAA/0.2 mM EDTA increased the Pb accumulation in leaves by about 2800% and by about 600%, as compared to Pb content in leaves of plants exposed to Pb alone and those cultivated with Pb/EDTA, respectively. These results indicate that non...
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Experimental results have shown that the desert plant species mesquite (Prosopis spp.) is capable of accumulating high levels of lead in the roots, translocating it to the aerial portion of the plant. One-week-old mesquite seedlings were... more
Experimental results have shown that the desert plant species mesquite (Prosopis spp.) is capable of accumulating high levels of lead in the roots, translocating it to the aerial portion of the plant. One-week-old mesquite seedlings were treated for 7 d in a hydroponic culture using a modified Hoagland solution. Six treatments were used; three treatments contained only Pb [as Pb(NO3)2] at 25-, 50-, and 75-mg L(-1) levels and three treatments contained the same levels of Pb, but with equimolar concentrations of disodium ethylenediamine tetraacetic acid (EDTA). Our results showed that the plants exposed to 25-, 50-, and 75-mg Pb L(-1) treatments without EDTA concentrated in stems 524, 3726, and 1417 mg kg(-1), respectively. However, the plants treated with Pb-EDTA concentrated in stems 480-, 607-, and 1247-mg Pb kg(-1) for the 25-, 50-, and 75-mg Pb L(-1) treatments, respectively. Results for the roots followed a similar trend; without EDTA the Pb levels ranged from 16,055, 89,935, an...
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Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean... more
Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean mesquite) would be a successful phytoextractor of copper in our local soils. In order to determine the feasibility of using Screw bean mesquite, we utilized inductively-coupled plasma-optical emission spectroscopy (ICP-OES) and elemental analysis to observe the uptake of copper and the effects on macro and micro nutrients within laboratory-grown seedlings. We have previously shown that P. pubescens is a hyperaccumulator of copper in soil-grown seedlings. Light and transmission electron microscopy demonstrated death of root cells and ultrastructural changes due to the presence of copper from 50 mg/L - 600 mg/L. Ultrastructural changes included plasmolysis, starch accumulation, increased vacuolation and swollen chloroplasts with disarranged thylakoid membranes in cotyledons. Inductively coupled plasma-optical emission spectroscopy analyses of macro- and micro-nutrients revealed that the presence of copper sulfate in the growth medium of Petri-dish grown Prosopis pubescens seedlings resulted in dramatic decreases of magnesium, potassium and phosphorus. At 500-600 mg/L of copper sulfate, a substantial increase of sulfur was present in roots.
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Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean... more
Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean mesquite) would be a successful phytoextractor of copper in our local soils. In order to determine the feasibility of using Screw bean mesquite, we utilized inductively-coupled plasma-optical emission spectroscopy (ICP-OES) and elemental analysis to observe the uptake of copper and the effects on macro and micro nutrients within laboratory-grown seedlings. We have previously shown that P. pubescens is a hyperaccumulator of copper in soil-grown seedlings. Light and transmission electron microscopy demonstrated death of root cells and ultrastructural changes due to the presence of copper from 50 mg/L - 600 mg/L. Ultrastructural changes included plasmolysis, starch accumulation, increased vacuolation and swollen chloroplasts with disarranged thylakoid membranes in cotyledons. Inductively coupled plasma-optical emission spectroscopy analyses of macro- and micro-nutrients revealed that the presence of copper sulfate in the growth medium of Petri-dish grown Prosopis pubescens seedlings resulted in dramatic decreases of magnesium, potassium and phosphorus. At 500-600 mg/L of copper sulfate, a substantial increase of sulfur was present in roots.
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Cadmium is a heavy metal, which, even at low concentrations, can be highly toxic to the growth and development of both plants and animals. Plant species vary extensively in their tolerance to excess cadmium in a growth medium and very few... more
Cadmium is a heavy metal, which, even at low concentrations, can be highly toxic to the growth and development of both plants and animals. Plant species vary extensively in their tolerance to excess cadmium in a growth medium and very few cadmium-tolerant species have been identified. In this study, tumbleweed plants (Salsola kali) grown in an agar-based medium with 20 mgl(-1) of Cd(II) did not show phytotoxicity, and their roots had the most biomass (4.5 mg) (P < 0.05) compared to the control plants (2.7 mg) as well as other treated plants. These plants accumulated 2696, 2075, and 2016 mg Cd kg(-1) of dry roots, stems, and leaves, respectively. The results suggest that there is no restricted cadmium movement in tumbleweed plants. In addition, the amount of Cd found in the dry leaf tissue suggests that tumbleweed could be considered as potential cadmium hyperaccumulating species. X-ray absorption spectroscopy studies demonstrated that in roots, cadmium was bound to oxygen while in stems and leaves, the metal was attached to oxygen and sulfur groups. This might imply that some small organic acids are responsible for Cd transport from roots to stems and leaves. In addition, it might be possible that the plant synthesizes phytochelatins in the stems, later coordinating the absorbed cadmium for transport and storage in cell structures. Thus, it is possible that in the leaves, Cd either exists as a Cd-phytochelatin complex or bound to cell wall structures. Current studies are being performed in order to elucidate the proposed hypothesis.
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Cadmium is a heavy metal, which, even at low concentrations, can be highly toxic to the growth and development of both plants and animals. Plant species vary extensively in their tolerance to excess cadmium in a growth medium and very few... more
Cadmium is a heavy metal, which, even at low concentrations, can be highly toxic to the growth and development of both plants and animals. Plant species vary extensively in their tolerance to excess cadmium in a growth medium and very few cadmium-tolerant species have been identified. In this study, tumbleweed plants (Salsola kali) grown in an agar-based medium with 20 mgl(-1) of Cd(II) did not show phytotoxicity, and their roots had the most biomass (4.5 mg) (P < 0.05) compared to the control plants (2.7 mg) as well as other treated plants. These plants accumulated 2696, 2075, and 2016 mg Cd kg(-1) of dry roots, stems, and leaves, respectively. The results suggest that there is no restricted cadmium movement in tumbleweed plants. In addition, the amount of Cd found in the dry leaf tissue suggests that tumbleweed could be considered as potential cadmium hyperaccumulating species. X-ray absorption spectroscopy studies demonstrated that in roots, cadmium was bound to oxygen while in stems and leaves, the metal was attached to oxygen and sulfur groups. This might imply that some small organic acids are responsible for Cd transport from roots to stems and leaves. In addition, it might be possible that the plant synthesizes phytochelatins in the stems, later coordinating the absorbed cadmium for transport and storage in cell structures. Thus, it is possible that in the leaves, Cd either exists as a Cd-phytochelatin complex or bound to cell wall structures. Current studies are being performed in order to elucidate the proposed hypothesis.
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Research Interests: Soil, Phytoremediation, Biological Sciences, Phosphorus, Environmental Sciences, and 15 moreXylem, Chromium, Nutrient Uptake, Lignin, Plant Roots, Metals, CHEMICAL SCIENCES, Sulfur, Germination, Infrared, Fabaceae, Fourier transform infrared spectroscopy, Time Factors, Soil Pollutants, and Plant Leaves
Research Interests: Soil, Phytoremediation, Biological Sciences, Phosphorus, Environmental Sciences, and 15 moreXylem, Chromium, Nutrient Uptake, Lignin, Plant Roots, Metals, CHEMICAL SCIENCES, Sulfur, Germination, Infrared, Fabaceae, Fourier transform infrared spectroscopy, Time Factors, Soil Pollutants, and Plant Leaves
Research Interests: Plant Biology, X ray absorption spectroscopy, Manganese, Micronutrients, Phosphorus, and 14 morePlant Physiology, Glutathione, Molybdenum, Plant Roots, Cadmium, Soil sciences, Plant Physiology and Biochemistry, Sulfur, Zea mays, Optical Emission Spectroscopy, Seedling, Cysteine, X ray Absorption, and Low molecular weight
The effects of arsenite [As(III)] and arsenate [As(V)] on the growth of roots, stems, and leaves and the uptake of arsenic (As), micro- and macronutrients, and total amylolytic activity were investigated to elucidate the phytotoxicity of... more
The effects of arsenite [As(III)] and arsenate [As(V)] on the growth of roots, stems, and leaves and the uptake of arsenic (As), micro- and macronutrients, and total amylolytic activity were investigated to elucidate the phytotoxicity of As to the mesquite plant (Prosopis juliflora x P. velutina). The plant growth was evaluated by measuring the root and shoot length, and the element uptake was determined using inductively coupled plasma optical emission spectroscopy. The root and leaf elongation decreased significantly with increasing As(III) and As(V) concentrations; whereas, stem elongation remained unchanged. The As uptake increased with increasing As(III) or As(V) concentrations in the medium. Plants treated with 50 mg/L As(III) accumulated up to 920 mg/kg dry weight (d wt) in roots and 522 mg/kg d wt in leaves, while plants exposed to 50 mg/L As(V) accumulated 1980 and 210 mg/kg d wt in roots and leaves, respectively. Increasing the As(V) concentration up to 20 mg/L resulted in a decrease in the total amylolytic activity. On the contrary, total amylolytic activity in As(III)-treated plants increased with increasing As concentration up to 20 mg/L. The macro- and micronutrient concentrations changed in As-treated plants. In shoots, Mo and K were reduced but Ca was increased, while in roots Fe and Ca were increased but K was reduced. These changes reduced the size of the plants, mainly in the As(III)-treated plants; however, there were no visible sign of As toxicity.
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... Kambhampati, MS, Begonia, GB, Begonia, MFT and Bufford, Y. 2003. Phytoremediation of a lead-contaminated soil using Morning Glory (Ipomoea lacunosa L.): Effects of a synthetic chelate. Bull. ... [Taylor... more
... Kambhampati, MS, Begonia, GB, Begonia, MFT and Bufford, Y. 2003. Phytoremediation of a lead-contaminated soil using Morning Glory (Ipomoea lacunosa L.): Effects of a synthetic chelate. Bull. ... [Taylor & Francis Online], [PubMed], [Web of Science ®] View all references). ...
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The effects of nCeO2 on food quality are not well known yet. This research was performed to determine the impact of nCeO2 on radish (Raphanus sativus L.). Plants were cultivated to full maturity in potting soil treated with nCeO2 at... more
The effects of nCeO2 on food quality are not well known yet. This research was performed to determine the impact of nCeO2 on radish (Raphanus sativus L.). Plants were cultivated to full maturity in potting soil treated with nCeO2 at concentrations of 0, 62.5, 125, 250, and 500 mg/kg. Germination, growth, photosynthesis, ionome, and antioxidants were evaluated at different growth stages. Results showed that at 500 mg/kg, nCeO2 significantly retarded seed germination but did not reduce the number of germinated seeds. None of the treatments affected gas exchange, photosynthesis, growth, phenols, flavonoids, and nutrients' accumulation in tubers and leaves of adult plants. However, tubers' antioxidant capacity, expressed as FRAP, ABTS(•-) and DPPH, increased by 30%, 32%, and 85%, respectively, in plants treated with 250 mg nCeO2kg(-1) soil. In addition, cerium accumulation in tubers of plants treated with 250 and 500 mg/kg reached 72 and 142 mg/kg d wt, respectively. This sugges...
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This study reports on the capability of the desert plant Chilopsis linearis (Cav.) Sweet (desert willow) to uptake gold (Au) from gold-enriched media at different plant-growth stages. Plants were exposed to 20, 40, 80, 160, and 320 mg Au... more
This study reports on the capability of the desert plant Chilopsis linearis (Cav.) Sweet (desert willow) to uptake gold (Au) from gold-enriched media at different plant-growth stages. Plants were exposed to 20, 40, 80, 160, and 320 mg Au L(-1) in agar-based growing media for 13, 18, 23, and 35 d. The Au content and oxidation state of Au in the plants were determined using an inductively coupled plasma/optical emission spectrometer (ICP/OES) and X-ray absorption spectroscopy (XAS), respectively. Gold concentrations ranging from 20 to 80 mg Au L(-1) did not significantly affect Chilopsis linearis plant growth. The concentration of gold in the plants increased as the age of the plant increased. The Au concentrations in leaves for the 20, 40, 80, and 160 mg Au L(-1) treatments were 32, 60, 62, and 179 mg Au kg(-1) dry weight mass, respectively, demonstrating the gold uptake capability of desert willow. The XAS data indicated that desert willow produced gold nanoparticles within plant tissues. Plants exposed to 160 mg Au L(-1) formed nanoparticles that averaged approximately 8, 35, and 18 A in root, stem, and leaves, respectively. It was observed that the average size of the Au nanoparticles formed by the plants is related to the total Au concentration in tissues and their location in the plant
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Abstract Although many metal elements are essential for the growth of plants in low concentrations, their excessive amounts in soil above threshold values can result in toxicity. This detrimental effect varies with the nature of an... more
Abstract Although many metal elements are essential for the growth of plants in low concentrations, their excessive amounts in soil above threshold values can result in toxicity. This detrimental effect varies with the nature of an element as well as plant species. Heavy ...
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Hexavalent chromium is a contaminant highly mobile in the environment that is toxic for plants at low concentrations. In this work, the physiological response of Convolvulus arvensis and Medicago truncatula plants to Cr(VI) treatments was... more
Hexavalent chromium is a contaminant highly mobile in the environment that is toxic for plants at low concentrations. In this work, the physiological response of Convolvulus arvensis and Medicago truncatula plants to Cr(VI) treatments was compared. C. arvensis is a potential Cr hyperaccumulator well adapted to semiarid conditions that biotransform Cr(VI) to the less toxic Cr(III). M. truncatula is a model plant well adapted to semiarid conditions with a well studied genetic response to heavy metal stress. The results demonstrated that C. arvensis is more tolerant to Cr toxicity and has a higher Cr translocation to the leaves. The inductively coupled plasma optical emission spectroscopy results showed that C. arvensis plants treated with 10 mg Cr(VI) L(-1) accumulated 1512, 210, and 131 mg Cr kg(-1) in roots, stems, and leaves, respectively. While M. truncatula plants treated with the same Cr(VI) concentration accumulated 1081, 331, and 44 (mg Cr kg(-1)) in roots, stems, and leaves, ...
Research Interests: Genetics, Phytoremediation, X ray absorption spectroscopy, Oxidative Stress, Biological Sciences, and 17 moreEnvironmental Sciences, Heavy Metal, Catalase, Chromium, Absorption, Plant Roots, Physiological Response, CHEMICAL SCIENCES, Optical Emission Spectroscopy, Seedling, Plant species, Hexavalent Chromium, Enzymatic Activity, Oxidation-Reduction, Soil Pollutants, Plant Leaves, and Ascorbate Peroxidase(Environmental Sciences, Heavy Metal, Catalase, Chromium, Absorption, Plant Roots, Physiological Response, CHEMICAL SCIENCES, Optical Emission Spectroscopy, Seedling, Plant species, Hexavalent Chromium, Enzymatic Activity, Oxidation-Reduction, Soil Pollutants, Plant Leaves, and Ascorbate Peroxidase)
(Environmental Sciences, Heavy Metal, Catalase, Chromium, Absorption, Plant Roots, Physiological Response, CHEMICAL SCIENCES, Optical Emission Spectroscopy, Seedling, Plant species, Hexavalent Chromium, Enzymatic Activity, Oxidation-Reduction, Soil Pollutants, Plant Leaves, and Ascorbate Peroxidase)
A pot experiment was conducted to evaluate the effects of the industrial effluent of the Hudiara drain on the growth and element accumulation by Eucalyptus camaldulensis at early growth stage. Plants were irrigated for 18 months with... more
A pot experiment was conducted to evaluate the effects of the industrial effluent of the Hudiara drain on the growth and element accumulation by Eucalyptus camaldulensis at early growth stage. Plants were irrigated for 18 months with effluent diluted with tap water at 0% (T0), 25% (T1), 50% (T2), 75% (T3), and 100% effluent (T4). Results showed that the maximum growth in terms of stem height (260 cm), number of branches (29), stem fresh weight (436.67 g), stem dry weight (203.33 g), total seedling length (344 cm), number of leaves (825), leaf fresh weight (195 g), and leaf dry weight (100 g) were recorded in plants treated with T2. However, maximum seedling collar diameter (2.25 cm), root fresh weight (230 g), and root dry weight (103.33 g) were observed in T3 treated plants. On the other hand, seedlings attained maximum root length (100.67 cm) at T1 treatment. Chlorophyll a, chlorophyll b and total chlorophyll increased up to T2, declining beyond that treatment. The accumulation of...