Sample records for hyperaccumulator thlaspi caerulescens1w

  1. Cadmium tolerance and antioxidative defenses in hairy roots of the cadmium hyperaccumulator,Thlaspi caerulescens

    Microsoft Academic Search

    Rengasamy Boominathan; Pauline M. Doran

    2003-01-01

    Plant species capable of hyperaccumulating heavy metals are of considerable interest for phytoreme- diation and phytomining. This work aims to identify the role of antioxidative metabolism in heavy metal toler- ance in the Cd hyperaccumulator, Thlaspi caerulescens. Hairy roots of T. caerulescens and the non-hyperaccumu- lator, Nicotiana tabacum (tobacco), were used to test the effects of high Cd environments. In

  2. Increased Glutathione Biosynthesis Plays a Role in Nickel Tolerance in Thlaspi Nickel HyperaccumulatorsW?

    PubMed Central

    Freeman, John L.; Persans, Michael W.; Nieman, Ken; Albrecht, Carrie; Peer, Wendy; Pickering, Ingrid J.; Salt, David E.

    2004-01-01

    Worldwide more than 400 plant species are now known that hyperaccumulate various trace metals (Cd, Co, Cu, Mn, Ni, and Zn), metalloids (As) and nonmetals (Se) in their shoots. Of these, almost one-quarter are Brassicaceae family members, including numerous Thlaspi species that hyperaccumulate Ni up to 3% of there shoot dry weight. We observed that concentrations of glutathione, Cys, and O-acetyl-l-serine (OAS), in shoot tissue, are strongly correlated with the ability to hyperaccumulate Ni in various Thlaspi hyperaccumulators collected from serpentine soils, including Thlaspi goesingense, T. oxyceras, and T. rosulare, and nonaccumulator relatives, including T. perfoliatum, T. arvense, and Arabidopsis thaliana. Further analysis of the Austrian Ni hyperaccumulator T. goesingense revealed that the high concentrations of OAS, Cys, and GSH observed in this hyperaccumulator coincide with constitutively high activity of both serine acetyltransferase (SAT) and glutathione reductase. SAT catalyzes the acetylation of l-Ser to produce OAS, which acts as both a key positive regulator of sulfur assimilation and forms the carbon skeleton for Cys biosynthesis. These changes in Cys and GSH metabolism also coincide with the ability of T. goesingense to both hyperaccumulate Ni and resist its damaging oxidative effects. Overproduction of T. goesingense SAT in the nonaccumulator Brassicaceae family member Arabidopsis was found to cause accumulation of OAS, Cys, and glutathione, mimicking the biochemical changes observed in the Ni hyperaccumulators. In these transgenic Arabidopsis, glutathione concentrations strongly correlate with increased resistance to both the growth inhibitory and oxidative stress induced effects of Ni. Taken together, such evidence supports our conclusion that elevated GSH concentrations, driven by constitutively elevated SAT activity, are involved in conferring tolerance to Ni-induced oxidative stress in Thlaspi Ni hyperaccumulators. PMID:15269333

  3. Investigating Heavy-metal Hyperaccumulation using Thlaspi caerulescens as a Model System

    PubMed Central

    Milner, Matthew J.; Kochian, Leon V.

    2008-01-01

    Background Metal-hyperaccumulating plant species are plants that are endemic to metalliferous soils and are able to tolerate and accumulate metals in their above-ground tissues to very high concentrations. One such hyperaccumulator, Thlaspi caerulescens, has been widely studied for its remarkable properties to tolerate toxic levels of zinc (Zn), cadmium (Cd) and sometimes nickel (Ni) in the soil, and accumulate these metals to very high levels in the shoot. The increased awareness regarding metal-hyperaccumulating plants by the plant biology community has helped spur interest in the possible use of plants to remove heavy metals from contaminated soils, a process known as phytoremediation. Hence, there has been a focus on understanding the mechanisms that metal-hyperaccumulator plant species such as Thlaspi caerulescens employ to absorb, detoxify and store metals in order to use this information to develop plants better suited for the phytoremediation of metal-contaminated soils. Scope In this review, an overview of the findings from recent research aimed at better understanding the physiological mechanisms of Thlaspi caerulescens heavy-metal hyperaccumulation as well as the underlying molecular and genetic determinants for this trait will be discussed. Progress has been made in understanding some of the fundamental Zn and Cd transport physiology in T. caerulescens. Furthermore, some interesting metal-related genes have been identified and characterized in this plant species, and regulation of the expression of some of these genes may be important for hyperaccumulation. Conclusions Thlaspi caerulescens is a fascinating and useful model system not only for studying metal hyperaccumulation, but also for better understanding micronutrient homeostasis and nutrition. Considerable future research is still needed to elucidate the molecular, genetic and physiological bases for the extreme metal tolerance and hyperaccumulation exhibited by plant species such as T. caerulescens. PMID:18440996

  4. CHARACTERIZATION OF ZINC TOLERANCE GENES IN THE ZINC/CADMIUM HYPERACCUMULATOR, THLASPI CAERULESCENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thlaspi caerulescens, a heavy metal hyperaccumulating plant species, accumulates up to 30,000 ppm zinc in the above ground biomass without exhibiting toxicity symptoms. Previous work in our lab has shown that altered regulation of micronutrient uptake, transport and sequestration in this species pla...

  5. Assessing the potential for zinc and cadmium phytoremediation with the hyperaccumulator Thlaspi caerulescens

    Microsoft Academic Search

    F. J. Zhao; E. Lombi; S. P. McGrath

    2003-01-01

    Thlaspi caerulescens is a Zn and Cd hyperaccumulator, and has been tested for its phytoremediation potential. In this paper we examine the relationships between the concentrations of Zn and Cd in soil and in T. caerulescens shoots, and calculate the rates of Zn and Cd extraction from soil. Using published data from field surveys, field and pot experiments, we show

  6. MOLECULAR AND PHYSIOLOGICAL INVESTIGATIONS OF THLASPI CAERULESCENS, A ZN/CD HYPERACCUMULATOR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain plant species have evolved specialized mechanisms that allow them to grow and thrive on metalliferous soils and accumulate high levels of heavy metals in the shoots that are toxic to normal plants. One such plant species is Thlaspi caerulescens, a Zn and Cd hyperaccumulator, and its metal h...

  7. ECOTYPIC VARIATION IN THE TRANSPORT, COMPARTMENTATION, AND COORDINATION OF CD BETWEEN POPULATIONS OF THE METAL HYPERACCUMULATOR, THLASPI CAERULESCENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hyperaccumulator Thlaspi caerulescens is known for its ability to hyperaccumulate and tolerate cadmium and zinc. This species is found in isolated, often small, populations across Great Britain, France, Belgium, and other European countries. While T. caerulescens populations from these different...

  8. Subcellular Localization and Speciation of Nickel in Hyperaccumulator and Non-Accumulator Thlaspi Species1

    PubMed Central

    Krämer, Ute; Pickering, Ingrid J.; Prince, Roger C.; Raskin, Ilya; Salt, David E.

    2000-01-01

    The ability of Thlaspi goesingense Hálácsy to hyperaccumulate Ni appears to be governed by its extraordinary degree of Ni tolerance. However, the physiological basis of this tolerance mechanism is unknown. We have investigated the role of vacuolar compartmentalization and chelation in this Ni tolerance. A direct comparison of Ni contents of vacuoles from leaves of T. goesingense and from the non-tolerant non-accumulator Thlaspi arvense L. showed that the hyperaccumulator accumulates approximately 2-fold more Ni in the vacuole than the non-accumulator under Ni exposure conditions that were non-toxic to both species. Using x-ray absorption spectroscopy we have been able to determine the likely identity of the compounds involved in chelating Ni within the leaf tissues of the hyperaccumulator and non-accumulator. This revealed that the majority of leaf Ni in the hyperaccumulator was associated with the cell wall, with the remaining Ni being associated with citrate and His, which we interpret as being localized primarily in the vacuolar and cytoplasm, respectively. This distribution of Ni was remarkably similar to that obtained by cell fractionation, supporting the hypothesis that in the hyperaccumulator, intracellular Ni is predominantly localized in the vacuole as a Ni-organic acid complex. PMID:10759531

  9. IDENTIFICATION AND CHARACTERIZATION OF A HEAVY METAL TRANSPORTING P-TYPE ATPASE FROM THE METAL HYPERACCUMULATING PLANT SPECIES, THLASPI CAERULESCENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thlaspi caerulescens is a Zn/Cd-hyperaccumulating plant species that can accumulate and tolerate up to30,000 ppm Zn and 4,000 ppm Cd in the shoots without exhibiting toxicity symptoms. As part of an overall program aimed at elucidating the molecular and physiological mechanisms of heavy metal hypera...

  10. Zinc ligands in the metal hyperaccumulator Thlaspi caerulescens as determined using X-ray absorption spectroscopy

    SciTech Connect

    Salt, D.E. [Northern Arizona Univ., Flagstaff, AZ (United States). Chemistry Dept.] [Northern Arizona Univ., Flagstaff, AZ (United States). Chemistry Dept.; Prince, R.C. [Exxon Research and Engineering, Annandale, NJ (United States)] [Exxon Research and Engineering, Annandale, NJ (United States); Baker, A.J.M. [Univ. of Sheffield (United Kingdom). Dept. of Animal and Plant Sciences] [Univ. of Sheffield (United Kingdom). Dept. of Animal and Plant Sciences; Raskin, I. [Rutgers Univ., New Brunswick, NJ (United States)] [Rutgers Univ., New Brunswick, NJ (United States); Pickering, I.J. [Stanford Synchrotron Radiation Lab., CA (United States)] [Stanford Synchrotron Radiation Lab., CA (United States)

    1999-03-01

    Using the noninvasive technique of X-ray absorption spectroscopy (XAS), the authors have been able to determine the ligand environment of Zn in different tissues of the Zn-hyperaccumulator Thlaspi caerulescens. The majority of intracellular Zn in roots of T. caerulescens was found to be coordinated with histidine. In the xylem sap Zn was found to be transported mainly as the free hydrated Zn{sup 2+} cation with a smaller proportion coordinated with organic acids. In the shoots, Zn coordination occurred mainly via organic acids, with a smaller proportion present as the hydrated cation and coordinated with histidine and the cell wall. Their data suggest that histidine plays an important role in Zn homeostasis in the roots, whereas organic acids are involved in xylem transport and Zn storage in shoots.

  11. Functional characterization of NRAMP3 and NRAMP4 from the metal hyperaccumulator Thlaspi caerulescens.

    PubMed

    Oomen, Ronald J F J; Wu, Jian; Lelièvre, Françoise; Blanchet, Sandrine; Richaud, Pierre; Barbier-Brygoo, Hélène; Aarts, Mark G M; Thomine, Sébastien

    2009-01-01

    The ability of metal hyperaccumulating plants to tolerate and accumulate heavy metals results from adaptations of metal homeostasis. NRAMP metal transporters were found to be highly expressed in some hyperaccumulating plant species. Here, we identified TcNRAMP3 and TcNRAMP4, the closest homologues to AtNRAMP3 and AtNRAMP4 in Thlaspi caerulescens and characterized them by expression analysis, confocal imaging and heterologous expression in yeast and Arabidopsis thaliana. TcNRAMP3 and TcNRAMP4 are expressed at higher levels than their A. thaliana homologues. When expressed in yeast TcNRAMP3 and TcNRAMP4 transport the same metals as their respective A. thaliana orthologues: iron (Fe), manganese (Mn) and cadmium (Cd) but not zinc (Zn) for NRAMP3; Fe, Mn, Cd and Zn for NRAMP4. They also localize at the vacuolar membrane in A. thaliana protoplasts. Inactivation of AtNRAMP3 and AtNRAMP4 in A. thaliana results in strong Cd and Zn hypersensitivity, which is fully rescued by TcNRAMP3 or TcNRAMP4 expression. However, metal tolerance conferred by TcNRAMP expression in nramp3nramp4 mutant does not exceed that of wild-type A. thaliana. Our data indicate that the difference between TcNRAMP3 and TcNRAMP4 and their A. thaliana orthologues does not lie in a different protein function, but probably resides in a different expression level or expression pattern. PMID:19054339

  12. Cellular Compartmentation of Zinc in Leaves of the Hyperaccumulator Thlaspi caerulescens1

    PubMed Central

    Küpper, Hendrik; Jie Zhao, Fang; McGrath, Steve P.

    1999-01-01

    Cellular compartmentation of Zn in the leaves of the hyperaccumulator Thlaspi caerulescens was investigated using energy-dispersive x-ray microanalysis and single-cell sap extraction. Energy-dispersive x-ray microanalysis of frozen, hydrated leaf tissues showed greatly enhanced Zn accumulation in the epidermis compared with the mesophyll cells. The relative Zn concentration in the epidermal cells correlated linearly with cell length in both young and mature leaves, suggesting that vacuolation of epidermal cells may promote the preferential Zn accumulation. The results from single-cell sap sampling showed that the Zn concentrations in the epidermal vacuolar sap were 5 to 6.5 times higher than those in the mesophyll sap and reached an average of 385 mm in plants with 20,000 ?g Zn g?1 dry weight of shoots. Even when the growth medium contained no elevated Zn, preferential Zn accumulation in the epidermal vacuoles was still evident. The concentrations of K, Cl, P, and Ca in the epidermal sap generally decreased with increasing Zn. There was no evidence of association of Zn with either P or S. The present study demonstrates that Zn is sequestered in a soluble form predominantly in the epidermal vacuoles in T. caerulescens leaves and that mesophyll cells are able to tolerate up to at least 60 mm Zn in their sap. PMID:9880373

  13. TcOPT3, a Member of Oligopeptide Transporters from the Hyperaccumulator Thlaspi caerulescens, Is a Novel Fe\\/Zn\\/Cd\\/Cu Transporter

    Microsoft Academic Search

    Yi Ting Hu; Feng Ming; Wei Wei Chen; Jing Ying Yan; Zheng Yu Xu; Gui Xin Li; Chun Yan Xu; Jian Li Yang; Shao Jian Zheng

    2012-01-01

    BackgroundThlaspi caerulescens is a natural selected heavy metal hyperaccumulator that can not only tolerate but also accumulate extremely high levels of heavy metals in the shoots. Thus, to identify the transportors involved in metal long-distance transportation is very important for understanding the mechanism of heavy metal accumulation in this hyperaccumulator.Methodology\\/Principal FindingsWe cloned and characterized a novel gene TcOPT3 of OPT

  14. Transcriptional regulation of metal transport genes and mineral nutrition during acclimation to cadium and zinc in the Cd/Zn hyperaccumulator, Thlaspi caerulescens (Ganges population)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated changes in mineral nutrient uptake and cellular expression levels of metal transporter genes using the Cd/Zn hyperaccumulator Thlaspi caerulescens. We analyzed those changes genesis under different long-term (one year) treatments of the plants with zinc and cadmium using quantitative...

  15. Metallothioneins 2 and 3 contribute to the metal-adapted phenotype but are not directly linked to Zn accumulation in the metal hyperaccumulator, Thlaspi caerulescens

    Microsoft Academic Search

    V. H. Hassinen; M. H. Tuomainen; S. Peraniemi; H. Schat; S. O. Karenlampi; A. I. Tervahauta

    2009-01-01

    To study the role of metallothioneins (MTs) in Zn accumulation, the expression of TcMT2a, TcMT2b, and TcMT3 was analysed in three accessions and 15 F3 families of two inter-accession crosses of the Cd\\/Zn hyperaccumulator Thlaspi caerulescens, with different degrees of Zn accumulation. The highest expression levels were found in the shoots of a superior metal-accumulating calamine accession from St Laurent

  16. Investigating Heavy-metal Hyperaccumulation using Thlaspi caerulescens as a Model System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperaccumulation was a term first coined by Brooks for plants that are endemic to metalliferous soils and are able to tolerate and accumulate large amounts of metals in their above ground tissues. Of the nearly 90 metal hyperaccumulating species in the Brassicaceae family, two species in particula...

  17. Altered Zn Compartmentation in the Root Symplasm and Stimulated Zn Absorption into the Leaf as Mechanisms Involved in Zn Hyperaccumulation in Thlaspi caerulescens

    PubMed Central

    Lasat, Mitch M.; Baker, Alan J.M.; Kochian, Leon V.

    1998-01-01

    We investigated Zn compartmentation in the root, Zn transport into the xylem, and Zn absorption into leaf cells in Thlaspi caerulescens, a Zn-hyperaccumulator species, and compared them with those of a related nonaccumulator species, Thlaspi arvense. 65Zn-compartmental analysis conducted with roots of the two species indicated that a significant fraction of symplasmic Zn was stored in the root vacuole of T. arvense, and presumably became unavailable for loading into the xylem and subsequent translocation to the shoot. In T. caerulescens, however, a smaller fraction of the absorbed Zn was stored in the root vacuole and was readily transported back into the cytoplasm. We conclude that in T. caerulescens, Zn absorbed by roots is readily available for loading into the xylem. This is supported by analysis of xylem exudate collected from detopped Thlaspi species seedlings. When seedlings of the two species were grown on either low (1 ?m) or high (50 ?m) Zn, xylem sap of T. caerulescens contained approximately 5-fold more Zn than that of T. arvense. This increase was not correlated with a stimulated production of any particular organic or amino acid. The capacity of Thlaspi species cells to absorb 65Zn was studied in leaf sections and leaf protoplasts. At low external Zn levels (10 and 100 ?m), there was no difference in leaf Zn uptake between the two Thlaspi species. However, at 1 mm Zn2+, 2.2-fold more Zn accumulated in leaf sections of T. caerulescens. These findings indicate that altered tonoplast Zn transport in root cells and stimulated Zn uptake in leaf cells play a role in the dramatic Zn hyperaccumulation expressed in T. caerulescens. PMID:9808732

  18. TcOPT3, a Member of Oligopeptide Transporters from the Hyperaccumulator Thlaspi caerulescens, Is a Novel Fe/Zn/Cd/Cu Transporter

    PubMed Central

    Hu, Yi Ting; Ming, Feng; Chen, Wei Wei; Yan, Jing Ying; Xu, Zheng Yu; Li, Gui Xin; Xu, Chun Yan; Yang, Jian Li; Zheng, Shao Jian

    2012-01-01

    Background Thlaspi caerulescens is a natural selected heavy metal hyperaccumulator that can not only tolerate but also accumulate extremely high levels of heavy metals in the shoots. Thus, to identify the transportors involved in metal long-distance transportation is very important for understanding the mechanism of heavy metal accumulation in this hyperaccumulator. Methodology/Principal Findings We cloned and characterized a novel gene TcOPT3 of OPT family from T. caerulescens. TcOPT3 was pronouncedly expressed in aerial parts, including stem and leaf. Moreover, in situ hybridization analyses showed that TcOPT3 expressed in the plant vascular systems, especially in the pericycle cells that may be involved in the long-distance transportation. The expression of TcOPT3 was highly induced by iron (Fe) and zinc (Zn) deficiency, especially in the stem and leaf. Sub-cellular localization showed that TcOPT3 was a plasma membrane-localized protein. Furthermore, heterogonous expression of TcOPT3 by mutant yeast (Saccharomyces cerevisiae) complementation experiments demonstrated that TcOPT3 could transport Fe2+ and Zn2+. Moreover, expression of TcOPT3 in yeast increased metal (Fe, Zn, Cu and Cd) accumulation and resulted in an increased sensitivity to cadmium (Cd) and copper (Cu). Conclusions Our data demonstrated that TcOPT3 might encode an Fe/Zn/Cd/Cu influx transporter with broad-substrate. This is the first report showing that TcOPT3 may be involved in metal long-distance transportation and contribute to the heavy metal hyperaccumulation. PMID:22761683

  19. Investigation of Heavy Metal Hyperaccumulation at the Cellular Level: Development and Characterization of Thlaspi caerulescens Suspension Cell Lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of metal hyperaccumulator plant species to accumulate high concentrations of toxic heavy metals requires the coordinated uptake, transport and sequestration of these metals to avoid damage to photosynthetic mechanisms. A number of previous studies have examined how hyperaccumulating pla...

  20. Cadmium sorption, influx, and efflux at the mesophyll layer of leaves from ecotypes of the Zn/Cd hyperaccumulator Thlaspi caerulescens

    SciTech Connect

    Ebbs, S.D.; Zambrano, M.C.; Spiller, S.M.; Newville, M. (SIU); (UC)

    2009-01-23

    Differential sorption and transport characteristics of the leaf mesophyll layer of the Prayon and Ganges ecotypes of the hyperaccumulator Thlaspi caerulescens were examined. {sup 109}Cd influx and efflux experiments were conducted with leaf sections, and X-ray absorption near edge structure (XANES) data were collected from leaves as a general comparison of in vivo cadmium (Cd) coordination. There were modest differences in cell wall sorption of Cd between ecotypes. There were obvious differences in time- and concentration-dependent Cd influx, including a greater V{sub MAX} for Prayon but a lower K{sub M} for Ganges for concentration-dependent Cd uptake and a notably greater Cd uptake by Ganges leaf sections at 1000 {micro}m Cd. Leaf sections of Prayon had a greater Cd efflux than Ganges. The XANES spectra from the two ecotypes suggested differences in Cd coordination. The fundamental differences observed between the two ecotypes may reflect differential activity and/or expression of plasma membrane and tonoplast transporters. More detailed study of these transporters and the in vivo coordination of Cd are needed to determine the contribution of these processes to metal homeostasis and tolerance.

  1. CREATION AND CHARACTERIZATION OF THLASPI CAERULESCENS AND THLASPI ARVENSE SUSPENSION CELL LINES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thlaspi caerulescens is a zinc and cadmium hyperaccumulator, capable of storing up to 30,000 ppm Zn or 10,000 ppm Cd in the shoots without exhibiting toxicity symptoms. Previous research demonstrates the heavy metal hyperaccumulation seen in T. caerulescens is due to altered regulation of uptake, tr...

  2. Expression differences for genes involved in lignin, glutathione and sulphate metabolism in response to cadmium in Arabidopsis thaliana and the related Zn\\/Cd-hyperaccumulator Thlaspi caerulescens

    Microsoft Academic Search

    Mortel van de J. E; HENK SCHAT; PERRY D. MOERLAND; EMIEL VER LOREN VAN THEMAAT; SJOERD VAN DER ENT; M. H. C. Blankestijn-de Vries; A. Ghandylian; STYLIANI TSIATSIANI; MARK G. M. AARTS

    2008-01-01

    Cadmium (Cd) is a widespread, naturally occurring element present in soil, rock, water, plants and animals. Cd is a non-essential element for plants and is toxic at higher concentrations. Transcript profiles of roots of Arabidopsis thaliana (Arabidopsis) and Thlaspi caerulescens plants exposed to Cd and zinc (Zn) are examined, with the main aim to determine the differences in gene expression

  3. The effect of plant cadmium and zinc status on root and shoot heavy metal accumulation in the heavy metal hyperaccumulator, Thlaspi caerulescens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thlaspi caerulescens is a plant species capable of tolerating and accumulating extremely high concentrations of the heavy metals, Zn and Cd, in the shoot. In this study, we investigated the impact of changes in plant heavy metal status (i.e. Zn and Cd) on the accumulation of heavy metals, including...

  4. Potential use of metal hyperaccumulators

    SciTech Connect

    Chaney, R.; Li, Yin-Ming; Green, C. [Environmental Chemistry Lab., Beltsville, MD (United States)] [and others

    1996-12-31

    Experiments involving biological accumulation of metal contaminants are summarized in the article. The focus is on identification of hyperaccumulating plant species for cadmium and zinc. Two of the studies examined Thlaspi caerulescens (alpine pennycress) as a bioadsorbent; the third study compared different species of Thlaspi. The T. caerulescens accumulated both metals, but with low yields. Other plant species were identified which adsorbed cadmium or zinc, but not both metals.

  5. www.newphytologist.org 517 Some plants hyperaccumulate selenium (Se) up to 1% of dry weight. This study

    E-print Network

    . · Selenium hyperaccumulators Astragalus bisulcatus and Stanleya pinnata were monitored over two growing: Astragalus bisulcatus, Astragalus sericoleucus, hyperaccumulation, Oxytropis sericea, selenium (Se), Stanleya pinnata, sulfur (S), Thlaspi montanum. New Phytologist (2007) 173: 517­525 © The Authors (2006). Journal

  6. Elevated expression of TcHMA3 plays a key role in the extreme Cd tolerance exhibited by a Cd-hyperaccumulating ecotype of Thlaspi caerulescens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cadmium (Cd) is a highly toxic heavy metal for plants, but several unique Cd hyperaccumulating plant species are able to accumulate this metal to extraordinary concentrations in the above-ground tissues without showing any toxic symptoms. However, the molecular mechanisms underlying this hyper-tole...

  7. Identification of Thlaspi caerulescens Genes That May Be Involved in Heavy Metal Hyperaccumulation and Tolerance. Characterization of a Novel Heavy Metal Transporting ATPase

    Microsoft Academic Search

    Ashot Papoyan; Leon V. Kochian

    2004-01-01

    and cadmium (Cd) in its shoots (30,000 m gg 21 Zn and 10,000 m gg 21 Cd), and has been the subject of intense research as a model plant to gain a better understanding of the mechanisms of heavy metal hyperaccumulation and tolerance and as a source of genes for developing plant species better suited for the phytoremediation of metal-contaminated

  8. Response of Thlaspi caerulescens to Nitrogen, Phosphorus and Sulfur Fertilisation

    Microsoft Academic Search

    Sirguey Catherine; Schwartz Christophe; Morel Jean Louis

    2006-01-01

    The main limiting factor for cleaning-up contaminated soils with hyperaccumulator plants is the low production of aerial biomass and the number of successive crops needed to reach the objective of remediation. The aim of this study was to contribute to the determination of a fertilisation strategy to optimise soil metal phytoextraction by Thlaspi caerulescens. A pot experiment was conducted on

  9. DIFFERENCES IN WHOLE CELL AND SINGLE CHANNEL ION CURRENTS ACROSS THE PLASMA MEMBRANE OF MESOPHYLL CELLS FROM TWO CLOSELY RELATED THLASPI SPECIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The patch clamp technique was used to study the physiology of ion transport in mesophyll cells from Thlaspi caerulescens, a heavy metal (Zn/Cd) hyperaccumulator species that can tolerate and accumulate very high levels of heavy metals in their leaf cells, and Thlaspi arvense, a related non-accumulat...

  10. Model evaluation of the phytoextraction potential of heavy metal hyperaccumulators and non-hyperaccumulators

    Microsoft Academic Search

    Hong-Ming Liang; Ting-Hsiang Lin; Jeng-Min Chiou; Kuo-Chen Yeh

    2009-01-01

    Evaluation of the remediation ability of zinc\\/cadmium in hyper- and non-hyperaccumulator plant species through greenhouse studies is limited. To bridge the gap between greenhouse studies and field applications for phytoextraction, we used published data to examine the partitioning of heavy metals between plants and soil (defined as the bioconcentration factor). We compared the remediation ability of the Zn\\/Cd hyperaccumulators Thlaspi

  11. Facultative hyperaccumulation of heavy metals and metalloids.

    PubMed

    Pollard, A Joseph; Reeves, Roger D; Baker, Alan J M

    2014-03-01

    Approximately 500 species of plants are known to hyperaccumulate heavy metals and metalloids. The majority are obligate metallophytes, species that are restricted to metalliferous soils. However, a smaller but increasing list of plants are "facultative hyperaccumulators" that hyperaccumulate heavy metals when occurring on metalliferous soils, yet also occur commonly on normal, non-metalliferous soils. This paper reviews the biology of facultative hyperaccumulators and the opportunities they provide for ecological and evolutionary research. The existence of facultative hyperaccumulator populations across a wide edaphic range allows intraspecific comparisons of tolerance and uptake physiology. This approach has been used to study zinc and cadmium hyperaccumulation by Noccaea (Thlaspi) caerulescens and Arabidopsis halleri, and it will be instructive to make similar comparisons on species that are distributed even more abundantly on normal soil. Over 90% of known hyperaccumulators occur on serpentine (ultramafic) soil and accumulate nickel, yet there have paradoxically been few experimental studies of facultative nickel hyperaccumulation. Several hypotheses suggested to explain the evolution of hyperaccumulation seem unlikely when most populations of a species occur on normal soil, where plants cannot hyperaccumulate due to low metal availability. In such species, it may be that hyperaccumulation is an ancestral phylogenetic trait or an anomalous manifestation of physiological mechanisms evolved on normal soils, and may or may not have direct adaptive benefits. PMID:24467891

  12. The potential of Thlaspi caerulescens for phytoremediation of contaminated soils

    Microsoft Academic Search

    Brett H. Robinson; Marc Leblanc; Daniel Petit; Robert R. Brooks; John H. Kirkman; Paul E. H. Gregg

    1998-01-01

    Uptake of Cd, Zn, Pb and Mn by the hyperaccumulator Thlaspi caerulescens was studied by pot trials in plant growth units and in populations of wild plants growing over Pb\\/Zn base-metal mine wastes at Les Malines in the south of France. The pot trials utilised metal-contaminated soils from Auby in the Lille area. Zinc and Cd concentrations in wild plants

  13. Molecular diversity and metal accumulation of different Thlaspi praecox populations from Slovenia

    Microsoft Academic Search

    Matevž Likar; Paula Pongrac; Katarina Vogel-Mikuš; Marjana Regvar

    2010-01-01

    Nuclear ribosomal sequences and Cd, Zn, Pb and Fe accumulation of different populations of the recently discovered Cd\\/Zn-hyperaccumulating\\u000a species Thlaspi praecox Wulfen (Noccaea) were studied to reveal their relationships to other representatives of the genus and especially to the well known hyperaccumulator\\u000a T. caerulescens; comparisons of their accumulating properties were also made. Internal transcribed spacer (ITS) rDNA sequences from eight

  14. Rhizosphere characteristics of indigenously growing nickel hyperaccumulator and excluder plants on serpentine soil

    Microsoft Academic Search

    W. W Wenzel; M Bunkowski; M Puschenreiter; O Horak

    2003-01-01

    The role of rhizosphere processes in metal hyperaccumulation is largely unexplored and a matter of debate, related field data are virtually not available. We conducted a field survey of rhizosphere characteristics beneath the Ni hyperaccumulator Thlaspi goesingense Hálácsy and the metal-excluder species Silene vulgaris L. and Rumex acetosella L. growing natively on the same serpentine site. Relative to bulk soil

  15. Metal hyperaccumulation in plants: mechanisms of defence against insect herbivores

    Microsoft Academic Search

    S. T. BEHMER; C. M. LLOYD; D. RAUBENHEIMER; J. STEWART-CLARK; J. KNIGHT; R. S. LEIGHTON; F. A. HARPER; J. A. C. SMITH

    2005-01-01

    Summary 1. To determine the mechanisms by which metal hyperaccumulation in plants could provide a chemical defence against insect herbivores, the feeding behaviour and per- formance of the desert locust, Schistocerca gregaria (Forskål), was investigated on plants of Thlaspi caerulescens J. & C. Presl containing different zinc concentrations, as well as on artificial food differing only in Zn content. 2.

  16. Response of Antioxidative Enzymes and Apoplastic Bypass Transport in Thlaspi Caerulescens and Raphanus Sativus to Cadmium Stress

    Microsoft Academic Search

    Saoussen Benzarti; Helmi Hamdi; Shino Mohri; Yoshiro Ono

    2010-01-01

    A hydroponics experiment using hyperaccumulator Thlaspi caerulescens (alpine pennycress) and non-specific accumulator Raphanus sativus (common radish) was conducted to investigate the short-term effect of increasing Cd concentrations (0, 25, 50, 75, 100 ?M) on metal uptake, chlorophyll content, antioxidative enzymes, and apoplastic bypass flow. As expected, T. caerulescens generally showed better resistance to metal stress, which was reflected by higher

  17. Heavy metal tolerance and accumulation in metallicolous and non-metallicolous populations of Thlaspi caerulescens from continental Europe

    Microsoft Academic Search

    Pierre Meerts; Nathalie Van Isacker

    1997-01-01

    In continental Europe, the heavy metal hyperaccumulator Thlaspi caerulescens occurs both on heavy-metal polluted soils (subsp. calaminare) and on soils with normal heavy metal content (subsp. caerulescens). In order to assess the extent and partitioning of variation in heavy metal tolerance and foliar mineral composition, twelve families from two populations of each subspecies were grown in pots in four soil

  18. Molecular dissection of the cellular mechanisms involved in nickel hyperaccumulation in plants. 1998 annual progress report

    SciTech Connect

    Salt, D.

    1998-06-01

    'Phytoremediation, the use of plants for environmental cleanup of pollutants, including toxic metals, holds the potential to allow the economic restoration of heavy metal and radionuclide contaminated sites. A number of terrestrial plants are known to naturally accumulate high levels of metals in their shoots (1--2% dry weight), and these plants have been termed metal-hyperaccumulators. Clearly, the genetic traits that determine metal-hyperaccumulation offers the potential for the development of practical phytoremediation processes. The long-term objective is to rationally design and generate plants ideally suited for phytoremediation using this unique genetic material. Initially, the strategy will focus on isolating and characterizing the key genetic information needed for expression of the metal-hyperaccumulation phenotype. Recently, histidine has been shown to play a major role in Ni hyperaccumulation. Based on this information the authors propose to investigate, at the molecular level, the role of histidine biosynthesis in Ni hyperaccumulation in Thlaspi goesingense, a Ni hyperaccumulator species.'

  19. Metal Hyperaccumulation Armors Plants against Disease

    PubMed Central

    Fones, Helen; Davis, Calum A. R.; Rico, Arantza; Fang, Fang; Smith, J. Andrew C.; Preston, Gail M.

    2010-01-01

    Metal hyperaccumulation, in which plants store exceptional concentrations of metals in their shoots, is an unusual trait whose evolutionary and ecological significance has prompted extensive debate. Hyperaccumulator plants are usually found on metalliferous soils, and it has been proposed that hyperaccumulation provides a defense against herbivores and pathogens, an idea termed the ‘elemental defense’ hypothesis. We have investigated this hypothesis using the crucifer Thlaspi caerulescens, a hyperaccumulator of zinc, nickel, and cadmium, and the bacterial pathogen Pseudomonas syringae pv. maculicola (Psm). Using leaf inoculation assays, we have shown that hyperaccumulation of any of the three metals inhibits growth of Psm in planta. Metal concentrations in the bulk leaf and in the apoplast, through which the pathogen invades the leaf, were shown to be sufficient to account for the defensive effect by comparison with in vitro dose–response curves. Further, mutants of Psm with increased and decreased zinc tolerance created by transposon insertion had either enhanced or reduced ability, respectively, to grow in high-zinc plants, indicating that the metal affects the pathogen directly. Finally, we have shown that bacteria naturally colonizing T. caerulescens leaves at the site of a former lead–zinc mine have high zinc tolerance compared with bacteria isolated from non-accumulating plants, suggesting local adaptation to high metal. These results demonstrate that the disease resistance observed in metal-exposed T. caerulescens can be attributed to a direct effect of metal hyperaccumulation, which may thus be functionally analogous to the resistance conferred by antimicrobial metabolites in non-accumulating plants. PMID:20838462

  20. Cadmium hyperaccumulation and genetic differentiation of Thlaspi caerulescens populations

    E-print Network

    Alvarez, Nadir

    for different environmental, soil, plant parameters and geographic origins of populations. Twenty-two populations were characterised with AFLP markers and cpDNA polymorphism. Over all loci, a partial Mantel test, when comparing the marker variation to a neutral model, seven AFLP fragments (9% of markers) were

  1. A native Zn/Cd transporting P1B ATPase from natural overexpression in a hyperaccumulator plant reveals post-translational processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TcHMA4 is a P1B-type ATPase that is highly expressed in the Cd/Zn hyperaccumulator plant Thlaspi caerulescens and contains a C-terminal 9-histidine repeat. After isolation from roots, we purified TcHMA4 protein via metal affinity chromatography. The purified protein exhibited Cd- and Zn activated AT...

  2. Characterization of the high affinity Zn transporter from Noccaea caerulescens, NcZNT1, and dissection of its promoter for its role in Zn uptake and hyperaccumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, we conducted a detailed analysis of the ZIP family transporter, NcZNT1, in the Zn/Cd hyperaccumulating plant species, Noccaea caerulescens, formerly known as Thlaspi caerulescens. NcZNT1 was previously suggested to be the primary root Zn/Cd uptake transporter. Both a characterization ...

  3. Molecular Dissection of the Cellular Mechanisms Involved in Nickel Hyperaccumulation in Plants

    SciTech Connect

    Salt, David E.

    1999-06-01

    Phytoremediation, the use of plants for environmental cleanup of pollutants, including toxic metals, holds the potential to allow the economic restoration of heavy metal and radionuclide contaminated sites. A number of terrestrial plants are known to naturally accumulate high levels of metals in their shoots (1-2% dry weight), and these plants have been termed metal-hyperaccumulators. Clearly, the genetic traits that determines metal-hyperaccumulation offers the potential for the development of practical phytoremediation processes. Our long-term objective is to rationally design and generate plants ideally suited for phytoremediation using this unique genetic material. Initially, our strategy will focus on isolating and characterizing the key genetic information needed for expression of the metal-hyperaccumulation phenotype. Recently, histidine has been shown to play a major role in Ni hyperaccumulation. Based on this information we propose to investigate, at the molecular level, the role of histidine biosynthesis in Ni hyperaccumulation in Thlaspi goesingense, a Ni hyperaccumulator species. We will clone key genes involved in histidine biosynthesis. We will characterize their transcriptional and post transcriptional regulation by histidine, Ni. We will determine if any of these genes are essential and sufficient for Ni hyperaccumulation by their expression in the non-hyperaccumulator Arabidopsis thaliana.

  4. Seasonal fluctuations of selenium and sulfur accumulation in selenium hyperaccumulators and related nonaccumulators.

    PubMed

    Galeas, Miriam L; Zhang, Li Hong; Freeman, John L; Wegner, Mellissa; Pilon-Smits, Elizabeth A H

    2007-01-01

    Some plants hyperaccumulate selenium (Se) up to 1% of dry weight. This study was performed to obtain insight into whole-plant Se fluxes in hyperaccumulators. Selenium hyperaccumulators Astragalus bisulcatus and Stanleya pinnata were monitored over two growing seasons for seasonal fluctuations in concentrations of Se and the chemically similar element sulfur (S). The related nonhyperaccumulators Astragalus sericoleucus, Oxytropis sericea and Thlaspi montanum were included for comparison. In both hyperaccumulators leaf Se decreased from April to October, coinciding with Se hyperaccumulation in flowers and seeds. Root Se levels were lowest in summer. Selenium concentration decreased with leaf age in both hyperaccumulators. Leaf S levels peaked in summer in all plant species, as did Se levels in nonhyperaccumulators. Selenium and S levels tended to be negatively correlated in hyperaccumulators, and positively correlated in nonhyperaccumulators. These results suggest a specific flow of Se in hyperaccumulator plants over the growing season, from root to young leaves in spring, followed by remobilization from aging leaves to reproductive tissues in summer, and back to roots in the autumn. PMID:17244046

  5. Rhizosphere characteristics of indigenously growing nickel hyperaccumulator and excluder plants on serpentine soil.

    PubMed

    Wenzel, W W; Bunkowski, M; Puschenreiter, M; Horak, O

    2003-01-01

    The role of rhizosphere processes in metal hyperaccumulation is largely unexplored and a matter of debate, related field data are virtually not available. We conducted a field survey of rhizosphere characteristics beneath the Ni hyperaccumulator Thlaspi goesingense Hálácsy and the metal-excluder species Silene vulgaris L. and Rumex acetosella L. growing natively on the same serpentine site. Relative to bulk soil and to the rhizosphere of the excluder species, we found significantly increased DOC and Ni concentrations in water extracts of T. goesingense rhizosphere, whereas exchangeable Ni was depleted due to excessive uptake of Ni. Chemical speciation analysis using the MINTEQA2 software package revealed that enhanced Ni solubility in Thlaspi rhizosphere is driven by the formation of Ni-organic complexes. Moreover, ligand-induced dissolution of Ni-bearing minerals is likely to contribute to enhanced Ni solubility. Increased Mg and Ca concentrations and pH in Thlaspi rhizosphere are consistent with ligand-induced dissolution of orthosilicates such as forsterite (Mg(2)SiO(4). Our field data reinforce the hypothesis that exudation of organic ligands may contribute to enhanced solubility and replenishment of metals in the rhizosphere of hyperaccumulating species. PMID:12663213

  6. Greenhouse evaluation of EDTA effectiveness at enhancing Cd, Cr, and Ni uptake in Helianthus annuus and Thlaspi caerulescens

    Microsoft Academic Search

    Jeffrey Munn; Mary January; Teresa J. Cutright

    2008-01-01

    Background, Aims and Scope  Phytoremediation is a promising means for the treatment of heavy metal contamination. Although several species have been identified\\u000a as hyperaccumulators, most studies have been conducted with only one metal. Experiments were conducted to investigate the\\u000a ability of Helianthus annuus and Thlaspi caerulescens to simultaneously uptake Cd, Cr and Ni.\\u000a \\u000a \\u000a \\u000a Materials and Methods  The efficiency of plants grown in

  7. Proteomics of Thlaspi caerulescens accessions and an inter-accession cross segregating for zinc accumulation.

    PubMed

    Tuomainen, Marjo; Tervahauta, Arja; Hassinen, Viivi; Schat, Henk; Koistinen, Kaisa M; Lehesranta, Satu; Rantalainen, Kimmo; Häyrinen, Jukka; Auriola, Seppo; Anttonen, Mikko; Kärenlampi, Sirpa

    2010-02-01

    Metal hyperaccumulator plants have previously been characterized by transcriptomics, but reports on other profiling techniques are scarce. Protein profiles of Thlaspi caerulescens accessions La Calamine (LC) and Lellingen (LE) and lines derived from an LCxLE cross were examined here to determine the co-segregation of protein expression with the level of zinc (Zn) hyperaccumulation. Although hydrophobic proteins such as membrane transporters are not disclosed, this approach has the potential to reveal other proteins important for the Zn hyperaccumulation trait. Plants were exposed to metals. Proteins were separated using two-dimensional electrophoresis and those showing differences among accessions, lines or metal exposures were subjected to mass-spectrometric analysis for identification. Crossing decreased the number of different proteins in the lines compared with the parents, more so in the shoots than in the roots, but the frequencies of Zn-responsive proteins were about the same in the accessions and the selection lines. This supports the finding that the Zn accumulation traits are mainly determined by the root and that Zn accumulation itself is not the reason for the co-segregation. This study demonstrates that crossing accessions with contrasting Zn accumulation traits is a potent tool to investigate the mechanisms behind metal hyperaccumulation. Four tentatively identified root proteins showed co-segregation with high or low Zn accumulation: manganese superoxide dismutase, glutathione S-transferase, S-formyl glutathione hydrolase, and translation elongation factor 5A-2. However, these proteins may not be the direct determinants of Zn accumulation. The role of these and other tentatively identified proteins in Zn accumulation and tolerance is discussed. PMID:20048332

  8. Nickel and zinc isotope fractionation in hyperaccumulating and nonaccumulating plants.

    PubMed

    Deng, Teng-Hao-Bo; Cloquet, Christophe; Tang, Ye-Tao; Sterckeman, Thibault; Echevarria, Guillaume; Estrade, Nicolas; Morel, Jean-Louis; Qiu, Rong-Liang

    2014-10-21

    Until now, there has been little data on the isotope fractionation of nickel (Ni) in higher plants and how this can be affected by plant Ni and zinc (Zn) homeostasis. A hydroponic cultivation was conducted to investigate the isotope fractionation of Ni and Zn during plant uptake and translocation processes. The nonaccumulator Thlaspi arvense, the Ni hyperaccumulator Alyssum murale and the Ni and Zn hyperaccumulator Noccaea caerulescens were grown in low (2 ?M) and high (50 ?M) Ni and Zn solutions. Results showed that plants were inclined to absorb light Ni isotopes, presumably due to the functioning of low-affinity transport systems across root cell membrane. The Ni isotope fractionation between plant and solution was greater in the hyperaccumulators grown in low Zn treatments (?(60)Ni(plant-solution) = -0.90 to -0.63‰) than that in the nonaccumulator T. arvense (?(60)Ni(plant-solution) = -0.21‰), thus indicating a greater permeability of the low-affinity transport system in hyperaccumulators. Light isotope enrichment of Zn was observed in most of the plants (?(66)Zn(plant-solution) = -0.23 to -0.10‰), but to a lesser extent than for Ni. The rapid uptake of Zn on the root surfaces caused concentration gradients, which induced ion diffusion in the rhizosphere and could result in light Zn isotope enrichment in the hyperaccumulator N. caerulescens. In high Zn treatment, Zn could compete with Ni during the uptake process, which reduced Ni concentration in plants and decreased the extent of Ni isotope fractionation (?(60)Ni(plant-solution) = -0.11 to -0.07‰), indicating that plants might take up Ni through a low-affinity transport system of Zn. We propose that isotope composition analysis for transition elements could become an empirical tool to study plant physiological processes. PMID:25222693

  9. Molecular dissection of the cellular mechanisms involved in nickel hyperaccumulation. 1997 annual progress report

    SciTech Connect

    Salt, D.E.

    1997-10-28

    'Phytoremediation, the use of plants for environmental cleanup of pollutants, including toxic metals, holds the potential to allow the economic restoration of heavy metal and radionuclide contaminated sites. A number of terrestrial plants are known to naturally accumulate high levels of metals in their shoots (1--2% dry weight), and these plants have been termed metal-hyperaccumulators. Clearly, the genetic traits that determine metal-hyperaccumulation offers the potential for the development of practical phytoremediation processes. The long-term objective is to rationally design and generate plants ideally suited for phytoremediation using this unique genetic material. Initially, the strategy will focus on isolating and characterizing the key genetic information needed for expression of the metal-hyperaccumulation phenotype. Recently, histidine has been shown to play a major role in Ni hyperaccumulation. Based on this information the authors propose to investigate, at the molecular level, the role of histidine biosynthesis in Ni hyperaccumuIation in Thlaspi goesingense, a Ni hyperaccumulator species.'

  10. Molecular dissection of the role of histidine in nickel hyperaccumulation in Thalspi goesingense (Halacsy)

    SciTech Connect

    Persans, M.W.; Yan, X.; Patnoe, J.M.M.L.; Kraemer, U.; Salt, D.E.

    1999-12-01

    To understand the role of free histidine (His) in Ni hyperaccumulation in Thlaspi goesingense, the authors investigated the regulation of His biosynthesis at both the molecular and biochemical levels. Three T. goesingense cDNAs encoding the following His biosynthetic enzymes, ATP phosphoribosyltransferase, imidazoleglycerol phosphate dehydratase, and histidinol dehydrogenase, were isolated by functional complementation of Escherichia coli His autotrophs. Northern analysis of THJG1, THD1, and THB1 gene expression revealed that each gene is expressed in both roots and shoots, but at the concentrations and dosage times of Ni treatment used in this study, these genes failed to show any regulation by Ni. The authors were also unable to observe any increases in the concentration of free His in root, shoot, or xylem sap of T. goesingense in response to Ni exposure. X-ray absorption spectroscopy of root and shoot tissue from T. goesingense and the non-accumulator species Thlaspi reverse revealed no major differences in the coordination of Ni by His in these tissues. They therefore conclude that the Ni hyperaccumulation phenotype in T. goesingense is not determined by the overproduction of His in response to Ni.

  11. MODE OF POLLINATION IN TWO THLASPI CAERULESCENS POPULATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thlaspi caerulescens, formerly known as T. alpestre, has been reported to be self-pollinated. Among T. alpestre plants, Riley (1956) found only 5.25 % outcrossing, whereas Holmgren (1971) found a range of 5-35% outcrossing. These studies suggest that T. caerulescens plants are predominantly self-p...

  12. Phytoextraction potential of the nickel hyperaccumulators Leptoplax emarginata and Bornmuellera tymphaea.

    PubMed

    Chardot, Vanessa; Massoura, Stamatia Tina; Echevarria, Guillaume; Reeves, Roger D; Morel, Jean-Louis

    2005-01-01

    Leptoplax emarginata and Bornmuellera tymphaea are nickel hyperaccumulators of the Brassicaceae family endemic to serpentine soils in Greece. The aims of this work were to compare the growth and uptake behavior of these plants with the Ni hyperaccumulator species Thlaspi caerulescens and Alyssum murale, and to evaluate their effect on soil Ni availability. Plants were grown for 3 mo on three soils that differ in Ni availability. Ni availability in soils was measuredby isotopic exchange kinetics and DTPA-TEA extractions. Results showed that L. emarginata produced significantly more biomass than other plants. On the serpentine soil, B. tymphaea showed the highest Ni concentration in shoots. However, Niphytoextraction on the three soils was maximal with L. emarginata. The high initial Ni availability of soil Serp (470.5 mg kg(-1)) was the main explanation for the high Ni concentrations measured in plant shoots grown on this soil, compared to those grown on soils Calc and Silt A. murale was the least efficient in reducing Ni availability on the serpentine soil L. emarginata appeared as the most efficient species for Ni phytoextraction and decrease of the Ni available pool. PMID:16463544

  13. Culturable endophytic bacteria enhance Ni translocation in the hyperaccumulator Noccaea caerulescens.

    PubMed

    Visioli, Giovanna; D'Egidio, Sara; Vamerali, Teofilo; Mattarozzi, Monica; Sanangelantoni, Anna Maria

    2014-12-01

    In this work, both culture-dependent and independent approaches were used to identify and isolate endophytic bacteria from roots of the Ni hyperaccumulator Noccaea caerulescens. A total of 17 isolates were cultured from root samples, selected for tolerance to 6mM Ni and grouped by restriction analysis of 16S rDNA. Bacterial species cultivated from roots belonged to seven genera, Microbacterium, Arthrobacter, Agreia, Bacillus, Sthenotrophomonas, Kocuria and Variovorax. The culture-independent approach confirmed the presence of Microbacterium and Arthrobacter while only other five clones corresponding to different amplified ribosomal DNA restriction patterns were detected. Five selected highly Ni-resistant bacteria showing also plant growth promoting activities, were inoculated into seeds of N. caerulescens, and in vivo microscopic analysis showed rapid root colonisation. Inoculated plants showed increased shoot biomass, root length and root-to-shoot Ni translocation. Root colonisation was also evident, but not effective, in the non-hyperaccumulating Thlaspi perfoliatum. Seed inoculation with selected Ni-resistant endophytic bacteria may represent a powerful tool in phytotechnologies, although transferring it to biomass species still requires further studies and screening. PMID:25277966

  14. Using hyperaccumulator plants to phytoextract soil Ni and Cd.

    PubMed

    Chaney, Rufus L; Angle, J Scott; McIntosh, Marla S; Reeves, Roger D; Li, Yin-Ming; Brewer, Eric P; Chen, Kuang-Yu; Roseberg, Richard J; Perner, Henrike; Synkowski, Eva Claire; Broadhurst, C Leigh; Wang, S; Baker, Alan J M

    2005-01-01

    Two strategies of phytoextraction have been shown to have promise for practical soil remediation: domestication of natural hyperaccumulators and bioengineering plants with the genes that allow natural hyperaccumulators to achieve useful phytoextraction. Because different elements have different value, some can be phytomined for profit and others can be phytoremediated at lower cost than soil removal and replacement. Ni phytoextraction from contaminated or mineralized soils offers economic return greater than producing most crops, especially when considering the low fertility or phytotoxicity of Ni rich soils. Only soils that require remediation based on risk assessment will comprise the market for phytoremediation. Improved risk assessment has indicated that most Zn + Cd contaminated soils will not require Cd phytoextraction because the Zn limits practical risk from soil Cd. But rice and tobacco, and foods grown on soils with Cd contamination without corresponding 100-fold greater Zn contamination, allow Cd to readily enter food plants and diets. Clear evidence of human renal tubular dysfunction from soil Cd has only been obtained for subsistence rice farm families in Asia. Because of historic metal mining and smelting, Zn + Cd contaminated rice soils have been found in Japan, China, Korea, Vietnam and Thailand. Phytoextraction using southern France populations of Thlaspi caerulescens appears to be the only practical method to alleviate Cd risk without soil removal and replacement. The southern France plants accumulate 10-20-fold higher Cd in shoots than most T. caerulescens populations such as those from Belgium and the UK. Addition of fertilizers to maximize yield does not reduce Cd concentration in shoots; and soil management promotes annual Cd removal. The value of Cd in the plants is low, so the remediation service must pay the costs of Cd phytoextraction plus profits to the parties who conduct phytoextraction. Some other plants have been studied for Cd phytoextraction, but annual removals are much lower than the best T. caerulescens. Improved cultivars with higher yields and retaining this remarkable Cd phytoextraction potential are being bred using normal plant breeding techniques. PMID:15948583

  15. ENDEMISM VS INVASIBILITY IN NICKEL HYPERACCUMULATORS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several species of nickel hyperaccumulators in the genus Alyssum are found on serpentine (ultramafic) soils throughout southern and eastern Europe and Asia, and some are endemic to serpentine substrates. This study examines the extent to which physiological factors restrict nickel hyperaccumulators ...

  16. Aerobic methane emissions from stinkweed (Thlaspi arvense) capsules.

    PubMed

    Qaderi, Mirwais M; Reid, David M

    2014-01-01

    Aerobic methane (CH4) emission from plant vegetative parts has been confirmed by many studies. However, the origin of aerobic CH4 from plants and its emission from reproductive parts have not been well documented. We determined the effects of developmental stages (early, mid, late) and incubation conditions (darkness, dim light, bright light) on CH4 emissions from stinkweed (Thlaspi arvense) capsules. We found that CH4 emissions from capsules varied with developmental stage and incubation light. Methane emission was highest for the late harvested capsules and for those incubated under lower (dim) light condition. Our results also showed a significant negative correlation between CH4 emission and capsule moisture content. We conclude that CH4 emissions vary with capsule age and diurnal light environment. PMID:25482797

  17. Characterization of the glyoxalase 1 gene TcGLX1 in the metal hyperaccumulator plant Thlaspi caerulescens

    Microsoft Academic Search

    Marjo Tuomainen; Viivi Ahonen; Sirpa O. Kärenlampi; Henk Schat; Tanja Paasela; Algirdas Švanys; Saara Tuohimetsä; Sirpa Peräniemi; Arja Tervahauta

    2011-01-01

    Stress tolerance is currently one of the major research topics in plant biology because of the challenges posed by changing\\u000a climate and increasing demand to grow crop plants in marginal soils. Increased Zn tolerance and accumulation has been reported\\u000a in tobacco expressing the glyoxalase 1-encoding gene from Brassica juncea. Previous studies in our laboratory showed some Zn tolerance-correlated differences in

  18. Compartmentation and complexation of metals in hyperaccumulator plants.

    PubMed

    Leitenmaier, Barbara; Küpper, Hendrik

    2013-01-01

    Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their "strange" behavior in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defense against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites (e.g., nicotianamine) and possibly for export of Cu in Cd/Zn hyperaccumulators [metallothioneins (MTs)]. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e., detoxified by binding to strong ligands such as MTs. PMID:24065978

  19. Compartmentation and complexation of metals in hyperaccumulator plants

    PubMed Central

    Leitenmaier, Barbara; Küpper, Hendrik

    2013-01-01

    Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their “strange” behavior in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defense against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites (e.g., nicotianamine) and possibly for export of Cu in Cd/Zn hyperaccumulators [metallothioneins (MTs)]. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e., detoxified by binding to strong ligands such as MTs. PMID:24065978

  20. Selenium hyperaccumulation reduces plant arthropod loads in the field

    Microsoft Academic Search

    Miriam L. Galeas; Erin M. Klamper; Lindsay E. Bennett; John L. Freeman; Boris C. Kondratieff; Colin F. Quinn; Elizabeth A. H. Pilon-Smits

    2008-01-01

    Summary • The elemental defense hypothesis proposes that some plants hyperaccumulate toxic elements as a defense mechanism. In this study the effectiveness of selenium (Se) as an arthropod deterrent was investigated under field conditions.  Arthropod loads were measured over two growing seasons in Se hyperaccumulator habitats in Colorado, USA, comparing Se hyperaccumulator species (Astragalus bisulca- tus and Stanleya pinnata)

  1. Selenium hyperaccumulation offers protection from cell disruptor herbivores

    Microsoft Academic Search

    Colin F Quinn; John L Freeman; Ray JB Reynolds; Jennifer J Cappa; Sirine C Fakra; Matthew A Marcus; Stormy D Lindblom; Erin K Quinn; Lindsay E Bennett; Elizabeth AH Pilon-Smits

    2010-01-01

    BACKGROUND: Hyperaccumulation, the rare capacity of certain plant species to accumulate toxic trace elements to levels several orders of magnitude higher than other species growing on the same site, is thought to be an elemental defense mechanism against herbivores and pathogens. Previous research has shown that selenium (Se) hyperaccumulation protects plants from a variety of herbivores and pathogens. Selenium hyperaccumulating

  2. Abstract Genetic polymorphism was investigated in Thlaspi caerulescens J. & C. Presl at 15 gene regions, of

    E-print Network

    Alvarez, Nadir

    and/or hyperaccumulation. Keywords CAPS Ã? Gene marker Ã? Microsatellite Ã? Phytoremediation Ã? Population genetics Introduction The development of studies on phytoremediation greatly increased the interest

  3. Thermoinductive regulation of gibberellin metabolism in Thlaspi arvense L

    SciTech Connect

    Hazebroek, J.P.; Metzger, J.D. (Department of Agriculture, Fargo, ND (USA))

    1990-09-01

    Field pennycress (Thlaspi arvense L.) is a winter annual crucifer with a cold requirement for stem elongation and flowering. In the present study, the metabolism of exogenous ({sup 2}H)-ent-kaurenoic acid (KA) and ({sup 14}C)-gibberellin A{sub 12}-aldehyde (GA{sub 12}-aldehyde) was compared in thermo- and noninduced plants. Thermoinduction greatly altered both quantitative and qualitative aspects of ({sup 2}H)-KA metabolism in the shoot tips. The rate of disappearance of the parent compound was much greater in thermoinduced shoot tips. These results are consistent with the suggestion that the conversion of KA in to GAs is under thermoinductive control only in the shoot tip, the site of perception for thermoinductive temperatures in field pennycress. There were essentially no differences in the qualitative or quantitative distribution of metabolites formed following the application of ({sup 14}C)GA{sub 12}-aldehyde to the shoot tips of thermo- or noninduced plants. Thus, the apparent thermoinductive regulation of the KA metabolism into GAs is probably limited to the two metabolic steps involved in converting KA to GA{sub 12}-aldehyde.

  4. Field Pennycress (Thlaspi arvense L.) Oil: A Promising Source of Biodiesel.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field pennycress (Thlaspi arvense L., FP) is a winter annual species of the mustard family (Brassicaceae) that is widely distributed throughout temperate North America and which can serve in a winter rotational cycle with conventional crops, thus not displacing existing agricultural production or ne...

  5. Preparation, composition and functional properties of pennycress (Thlaspi arvense L.) seed protein isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated two methods, saline extraction (SE) and conventional acid precipitation (AP), to recover proteins from pennycress (Thlaspi arvense L.) seed meal. SE was done using 0.1 M NaCl at 50ºC while AP involved alkaline extraction (pH 10) first followed by protein precipitation at pH 4. C...

  6. Registration of Katelyn Thlaspi arvense L. (Pennycress) with improved nondormant traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Katelyn (Reg. No. GP-35, PI 673443) pennycress (Thlaspi arvense L.) was publicly released by the USDA-ARS in 2014 as part of a new crop improvement program. Katelyn was developed by two generations of mass selection based on the germination response of freshly harvested pennycress seeds. The origina...

  7. Production and Evaluation of Biodiesel from Field Pennycress (Thlaspi Arvense L.) Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field pennycress (Thlaspi arvense L.) oil is evaluated for the first time as a potential feedstock for biodiesel production. Biodiesel was obtained in 82 wt % yield by a standard transesterification procedure with methanol and sodium methoxide catalyst at 60 deg C and an alcohol to oil ratio of 6:1...

  8. Composition and physical properties of cress ( Lepidium sativum L.) and field pennycress ( Thlaspi arvense L .) oils

    Microsoft Academic Search

    Bryan R. Moser; Shailesh N. Shah; Jill K. Winkler-Moser; Steven F. Vaughn; Roque L. Evangelista

    2009-01-01

    The fatty acid profiles and tocopherol and phytosterol contents of crude oils of cress (Lepidium sativum L.) and field pennycress (Thlaspi arvense L.) are reported, along with yields from the corresponding seeds. The physical properties of these oils were also determined, which included oxidative stability, kinematic viscosity, viscosity index, low temperature fluidity, specific gravity, acid value, lubricity, and iodine value.

  9. Composition and Physical Properties of Cress (Lepidium sativum L.) and Field Pennycress (Thlaspi arvense L.) Oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fatty acid profile and tocopherol, and phytosterol contents of crude cress (Lepidium sativum L.) and field pennycress (Thlaspi arvense L.) oils are reported, along with yields from the corresponding seeds. The physical properties of these oils were also determined, which included oxidative stab...

  10. Composition and functional properties of protein recovered from pennycreess (Thlaspi arvense) press cake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress (Thlaspi arvense L.) seed oil is being considered as alternative feedstock for biodiesel production. If the pennycress-based biodiesel venture is successful, then the seed protein (more than 20% content) could become a major co-product of the process. This study compared two methods for e...

  11. Emergence of field pennycress (Thlaspi arvense L.): Comparison of two accessions and modelling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many weed species are becoming rare due to intense agricultural management, which leads to a decrease of biodiversity in agroecosystems. Cultivating some of these species for their oilseed content may help preserve them while profiting agronomically. Thlaspi arvense is one of these species with pote...

  12. Effects of arsenic on nitrate metabolism in arsenic hyperaccumulating and non-hyperaccumulating ferns

    E-print Network

    Ma, Lena

    Effects of arsenic on nitrate metabolism in arsenic hyperaccumulating and non Arsenic reduced the activity of nitrate and nitrite reductase more in Pteris ensiformis than Pteris March 2009 Accepted 26 March 2009 Keywords: Arsenic Nitrate metabolism Pteris vittata Arsenic

  13. PHYTOEXTRACTION OF HEAVY METALS WITH HYPERACCUMULATOR PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When soils contain metals at high enough levels to comprise risk thru food-chain or soil ingestion, some methods must be applied to alleviate the risk, or the land use must be constrained. One approach to remediate risks from some metals is phytoextraction using hyperaccumulator plants. These remark...

  14. Comparative genome organization reveals a single copy of CBF in the freezing tolerant crucifer Thlaspi arvense

    Microsoft Academic Search

    Ning Zhou; Stephen J. Robinson; Terry Huebert; Nicholas J. Bate; Isobel A. P. Parkin

    2007-01-01

    The weedy crucifer species Thlaspi arvense has the ability to acclimate to lower temperatures than Arabidopsis thaliana and the related crop species, Brassica napus. As a step towards understanding the genetic basis for this enhanced low temperature response, we isolated and sequenced\\u000a 8.7 kb of genomic DNA encompassing the T. arvense CBF locus. CBF is a transcription factor believed to play a

  15. SOIL MICROBIAL EFFECTS ON HEAVY METAL UPTAKE INTO HYPERACCUMULATORS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uptake of heavy metals into hyperaccumulators is influenced by a number of chemical, physical and biological factors. Of these, recent evidence has shown that microbes living within the rhizosphere of hyperaccumulators may have a significant effect on metal uptake. Much is known about the role my...

  16. XAS Speciation of Arsenic in a Hyper-Accumulating Fern

    E-print Network

    Ma, Lena

    XAS Speciation of Arsenic in a Hyper-Accumulating Fern S A M U E L M . W E B B , J E A N - F R A N environment and the redox speciation of arsenic in a newly discovered arsenic hyper-accumulating fern (Pteris high As concentrations (ca. 1% As per dry weight) arsenic in the fern leaves is coordinated

  17. Molecular mechanisms of heavy metal hyperaccumulation and phytoremediation

    Microsoft Academic Search

    Xiaoe Yang; Ying Feng; Zhenli He; Peter J. Stoffella

    2005-01-01

    A relatively small group of hyperaccumulator plants is capable of sequestering heavy metals in their shoot tissues at high concentrations. In recent years, major scientific progress has been made in understanding the physiological mechanisms of metal uptake and transport in these plants. However, relatively little is known about the molecular bases of hyperaccumulation. In this paper, current progresses on understanding

  18. Forms of Zinc Accumulated in the Hyperaccumulator Arabidopsis halleri1

    E-print Network

    -tolerant and hyperaccumulator Arabidopsis halleri and in the non-tolerant and nonaccumulator Arabidopsis lyrata subsp. petraeaForms of Zinc Accumulated in the Hyperaccumulator Arabidopsis halleri1 Ge´raldine Sarret*, Pierre citrate, and Zn phosphate. Zn phosphate was present in both the roots and aerial part of A. lyrata subsp

  19. Effects of arsenic on nitrogen metabolism in arsenic hyperaccumulator and non-hyperaccumulator ferns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of two four-month old fern plants, Pteris vittata, an arsenic-hyperaccumulator, and Pteris ensiformis, ...

  20. Selenium hyperaccumulation reduces plant arthropod loads in the field.

    PubMed

    Galeas, Miriam L; Klamper, Erin M; Bennett, Lindsay E; Freeman, John L; Kondratieff, Boris C; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2008-01-01

    The elemental defense hypothesis proposes that some plants hyperaccumulate toxic elements as a defense mechanism. In this study the effectiveness of selenium (Se) as an arthropod deterrent was investigated under field conditions. Arthropod loads were measured over two growing seasons in Se hyperaccumulator habitats in Colorado, USA, comparing Se hyperaccumulator species (Astragalus bisulcatus and Stanleya pinnata) with nonhyperaccumulators (Camelina microcarpa, Astragalus americanus, Descurainia pinnata, Medicago sativa, and Helianthus pumilus). The Se hyperaccumulating plant species, which contained 1000-14 000 microg Se g(-1) DW, harbored significantly fewer arthropods (c. twofold) and fewer arthropod species (c. 1.5-fold) compared with nonhyperaccumulator species that contained < 30 microg Se g(-1) DW. Arthropods collected on Se-hyperaccumulating plants contained three- to 10-fold higher Se concentrations than those found on nonhyperaccumulating species, but > 10-fold lower Se concentrations than their hyperaccumulator hosts. Several arthropod species contained > 100 microg Se g(-1) DW, indicating Se tolerance and perhaps feeding specialization. These results support the elemental defense hypothesis and suggest that invertebrate herbivory may have contributed to the evolution of Se hyperaccumulation. PMID:18028291

  1. Effects of arsenic on nitrate metabolism in arsenic hyperaccumulating and non-hyperaccumulating ferns.

    PubMed

    Singh, Nandita; Ma, Lena Q; Vu, Joseph C; Raj, Anshita

    2009-01-01

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of four-month old Pteris vittata (arsenic - hyperaccumulator) and Pteris ensiformis (non-arsenic-hyperaccumulator) plants. The arsenic treatments (0, 150, and 300 microM as sodium arsenate) in hydroponics had adverse effects on the root and frond dry weights, and this effect was more evident in P. ensiformis than in P. vittata. Nitrate reductase and nitrite reductase activities of arsenate-treated plants were reduced more in P. ensiformis than in P. vittata. This effect was accompanied by similar decreases in tissue NO(3)(-) concentrations. Therefore, this decrease is interpreted as being indirect, i.e., the consequence of the reduced NO(3)(-) uptake and translocation in the plants. The study shows the difference in the tolerance level of the two Pteris species with varying sensitivity to arsenic. PMID:19406540

  2. Leaf flavonoids of the cruciferous species, Camelina sativa, Crambe spp., Thlaspi arvense and several other genera of the family Brassicaceae

    Microsoft Academic Search

    Joseph Onyilagha; Adil Bala; Rebecca Hallett; Margaret Gruber; Juliana Soroka; Neil Westcott

    2003-01-01

    The flavonoid profiles of 22 accessions of Camelina sativa and five other crucifer species, Crambe abyssinica, Crambe hispanica, Thlaspi arvense, Brassica napus, and Sinapis alba, were studied by a combination of liquid, paper and thin layer chromatography. Flavonoids were confirmed by comparison of their characteristics, including colour under UV light, changes to colour under UV with fuming in NH3 vapour,

  3. Effects of oil extraction on functional properties of protein in pennycress (Thlaspi arvense) seed and press cake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current interest in pennycress (Thlaspi arvense) comes from its seed oil, which is being evaluated for biodiesel production. The seed also has notable protein content (33% db). The effects of oil processing conditions on functionality of pennycress seed proteins were determined to identify potential...

  4. Cd hyperaccumulative characteristics of Australia ecotype Solanum nigrum L. and its implication in screening hyperaccumulator.

    PubMed

    Wei, Shuhe; Clark, Gary; Doronila, Augustine Ignatius; Jin, Jian; Monsant, Alison Carol

    2013-01-01

    A pot culture experiment was used to determine the differences in uptake characteristics of a cadmium hyperaccumulator Solanum nigrum L. discovered in China, an ecotype from Melbourne, Australia and a non-hyperaccumulator Solanum melogena Australian ecotype was not significantly different to the China ecotype. In particular, Cd concentration in leaves and shoots of S. nigrum collected from Australia were 166.0 and 146.3 mg kg(-1) respectively when 20 mg kg(-1) Cd spiked, and were not significantly different to the ecotype imported from China which had 109.8 and 85.3 mg kg(-1) respectively, in the stems and leaves. In contrast, the tolerance of the eggplant to Cd was significantly less than the two S. nigrum ecotypes. Although some morphological properties of S. nigrum collected from Australia were different from that of the plants collected from China, Cd hyperaccumulator characteristics of two ecotypes were similar. The results suggested that the tolerance and uptake of Cd may be a constitutive trait of this species. PMID:23488006

  5. Tolerance to cadmium in plants: the special case of hyperaccumulators.

    PubMed

    Verbruggen, Nathalie; Juraniec, Michal; Baliardini, Cecilia; Meyer, Claire-Lise

    2013-08-01

    On sols highly polluted by trace metallic elements the majority of plant species are excluders, limiting the entry and the root to shoot translocation of trace metals. However a rare class of plants called hyperaccumulators possess remarkable adaptation because those plants combine extremely high tolerance degrees and foliar accumulation of trace elements. Hyperaccumulators have recently gained considerable interest, because of their potential use in phytoremediation, phytomining and biofortification. On a more fundamental point of view hyperaccumulators of trace metals are case studies to understand metal homeostasis and detoxification mechanisms. Hyperaccumulation of trace metals usually depends on the enhancement of at least four processes, which are the absorption from the soil, the loading in the xylem in the roots and the unloading from the xylem in the leaves and the detoxification in the shoot. Cadmium is one of the most toxic trace metallic elements for living organisms and its accumulation in the environment is recognized as a worldwide concern. To date, only nine species have been recognized as Cd hyperaccumulators that is to say able to tolerate and accumulate more than 0.01 % Cd in shoot dry biomass. Among these species, four belong to the Brassicaceae family with Arabidopsis halleri and Noccaea caerulescens being considered as models. An update of our knowledge on the evolution of hyperaccumulators will be presented here. PMID:23881358

  6. The role of phytochelatins in constitutive and adaptive heavy metal toleances in hyperaccumulator and non-hyperaccumulator metallophytes

    Microsoft Academic Search

    Henk Schat; M. Llugany; H. Vooijs; J. Hartley-Whitaker; P. M. Bleeker

    2002-01-01

    Using the g-glutamylcysteine synthetase inhibitor, L-buthionine-(S,R)-sulphoximine (BSO), the role for phytochelatins (PCs) was evaluated in Cu, Cd, Zn, As, Ni, and Co tolerance in non-metallicolous and metallicolous, hypertolerant populations of Silene vulgaris (Moench) Garcke, Thlaspi caerulescens J.&C. Presl., Holcus lanatus L., and Agrostis castel- lana Boiss. et Reuter. Based on plant-internal PC- thiol to metal molar ratios, the metals' tendency

  7. Arsenic speciation, and arsenic and phosphate distribution in arsenic hyperaccumulator Pteris vittata L. and

    E-print Network

    Ma, Lena

    Arsenic speciation, and arsenic and phosphate distribution in arsenic hyperaccumulator Pteris examined the roles of arsenic translocation and reduction, and P distribution in arsenic detoxification of Pteris vittata L. (Chinese Brake fern), an arsenic hyperaccumulator and Pteris ensiformis L. (Slender

  8. Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.)

    E-print Network

    Ma, Lena

    Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris June 2002; accepted 9 December 2002 ``Capsule'': Arsenic was predominantly present as inorganic arsenite in the fronds of the hyperaccumulator Chinese brake. Abstract Arsenic speciation is important

  9. Effects of selenium hyperaccumulation on plant-plant interactions: evidence for elemental allelopathy?

    PubMed

    El Mehdawi, Ali F; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2011-07-01

    • Few studies have investigated plant-plant interactions involving hyperaccumulator plants. Here, we investigated the effect of selenium (Se) hyperaccumulation on neighboring plants. • Soil and litter Se concentrations were determined around the hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and around the nonhyperaccumulators Medicago sativa and Helianthus pumilus. We also compared surrounding vegetative cover, species composition and Se concentration in two plant species (Artemisia ludoviciana and Symphyotrichum ericoides) growing either close to or far from Se hyperaccumulators. Then, Arabidopsis thaliana germination and growth were compared on soils collected next to the hyperaccumulators and the nonhyperaccumulators. • Soil collected around hyperaccumulators contained more Se (up to 266 mg Se kg(-1) ) than soil collected around nonhyperaccumulators. Vegetative ground cover was 10% lower around Se hyperaccumulators compared with nonhyperaccumulators. The Se concentration was higher in neighboring species A. ludoviciana and S. ericoides when growing close to, compared with far from, Se hyperaccumulators. A. thaliana showed reduced germination and growth, and higher Se accumulation, when grown on soil collected around Se hyperaccumulators compared with soil collected around nonaccumulators. • In conclusion, Se hyperaccumulators may increase the surrounding soil Se concentration (phytoenrichment). The enhanced soil Se contents around hyperaccumulators can impair the growth of Se-sensitive plant species, pointing to a possible role of Se hyperaccumulation in elemental allelopathy. PMID:21371042

  10. Spatial Imaging, Speciation, and Quantification of Selenium in the Hyperaccumulator Plants Astragalus bisulcatus and Stanleya pinnata

    Microsoft Academic Search

    John L. Freeman; Li Hong Zhang; Matthew A. Marcus; Sirine Fakra; Steve P. McGrath

    2006-01-01

    Astragalus bisulcatus and Stanleya pinnata hyperaccumulate selenium (Se) up to 1% of plant dry weight. In the field, Se was mostly present in the young leaves and reproductive tissues of both hyperaccumulators. Microfocused scanning x-ray fluorescence mapping revealed that Se was hyperaccumulated in trichomes in young leaves of A. bisulcatus. None of 10 other elements tested were accumulated in trichomes.

  11. A novel WRKY transcriptional factor from Thlaspi caerulescens negatively regulates the osmotic stress tolerance of transgenic tobacco

    Microsoft Academic Search

    Wei Wei; Yuxiu Zhang; Lu Han; Ziqiu Guan; Tuanyao Chai

    2008-01-01

    A novel member of the WRKY gene family, designated TcWRKY53, was isolated from a cadmium (Cd)-treated Thlaspi caerulescens cDNA library by differential screening. WRKY proteins specifically bind to W-boxes, which are found in the promoters of many\\u000a genes involved in defense and response to environmental stress. TcWRKY53 contains a 975-bp open reading frame encoding a putative protein of 324 amino

  12. Arsenic Hyperaccumulation in Gametophytes of Pteris vittata. A New Model System for Analysis of Arsenic Hyperaccumulation1

    PubMed Central

    Gumaelius, Luke; Lahner, Brett; Salt, David E.; Banks, Jo Ann

    2004-01-01

    The sporophyte of the fern Pteris vittata is known to hyperaccumulate arsenic (As) in its fronds to >1% of its dry weight. Hyperaccumulation of As by plants has been identified as a valuable trait for the development of a practical phytoremediation processes for removal of this potentially toxic trace element from the environment. However, because the sporophyte of P. vittata is a slow growing perennial plant, with a large genome and no developed genetics tools, it is not ideal for investigations into the basic mechanisms underlying As hyperaccumulation in plants. However, like other homosporous ferns, P. vittata produces and releases abundant haploid spores from the parent sporophyte plant which upon germination develop as free-living, autotrophic haploid gametophyte consisting of a small (<1 mm) single-layered sheet of cells. Its small size, rapid growth rate, ease of culture, and haploid genome make the gametophyte a potentially ideal system for the application of both forward and reverse genetics for the study of As hyperaccumulation. Here we report that gametophytes of P. vittata hyperaccumulate As in a similar manner to that previously observed in the sporophyte. Gametophytes are able to grow normally in medium containing 20 mm arsenate and accumulate >2.5% of their dry weight as As. This contrasts with gametophytes of the related nonaccumulating fern Ceratopteris richardii, which die at even low (0.1 mm) As concentrations. Interestingly, gametophytes of the related As accumulator Pityrogramma calomelanos appear to tolerate and accumulate As to intermediate levels compared to P. vittata and C. richardii. Analysis of gametophyte populations from 40 different P. vittata sporophyte plants collected at different sites in Florida also revealed the existence of natural variability in As tolerance but not accumulation. Such observations should open the door to the application of new and powerful genetic tools for the dissection of the molecular mechanisms involved in As hyperaccumulation in P. vittata using gametophytes as an easily manipulated model system. PMID:15448194

  13. Improved Understanding of Hyperaccumulation Yields Commercial Phytoextraction and Phytomining Technologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reviews progress in phytoextraction of soil elements and illustrates the key role of hyperaccumulator plant species in useful technologies. Much research has focused on elements which are not practically phytoextracted (Pb); on addition of chelating agents which cause unacceptable contam...

  14. REGULAR ARTICLE Hyperaccumulation of nickel by Alyssum corsicum

    E-print Network

    Sparks, Donald L.

    and plant transpiration rate. The most soluble compounds had the highest Ni uptake, with the exception of Ni plant uptake and transpiration rate. In ser- pentine soils and insoluble NiO plant transpiration rate and the plant transpiration rate. Keywords Ni minerals . Alyssum . Hyperaccumulators . Ni solubility

  15. Antimony uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata

    E-print Network

    Ma, Lena

    Antimony uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata Rujira Tisarum 2013 Keywords: Antimony Pteris vittata Uptake Translocation Speciation a b s t r a c t Even though antimony (Sb) and arsenic (As) are chemical analogs, differences exist on how they are taken up

  16. REGULAR ARTICLE Enhanced decomposition of selenium hyperaccumulator litter

    E-print Network

    populations of the Se hyperaccumulator Astragalus bisulcatus (one population with 350 and the other with 550 mg Se kg-1 DW) and from the related non-accumulator species Astragalus drummondii and Medicago sativa Astragalus bisulcatus . Hyperacccumulating plant . Litterbag . Detrivore . Decomposer Introduction Leaf

  17. REGULAR ARTICLE Enhanced decomposition of selenium hyperaccumulator litter

    E-print Network

    litter were compared between litter from two populations of the Se hyperaccumulator Astragalus bisulcatus-accumulator species Astragalus drummondii and Medicago sativa containing 1­2 mg Se kg-1 DW using a litterbag method and Watershed Stewardship, Colorado State University, Fort Collins, CO 80523, USA #12;Keywords Astragalus

  18. Blackwell Publishing Ltd Hyperaccumulator Alyssum murale relies on a different

    E-print Network

    strategies are necessary when vast areas of land have been contaminated. Hyperaccumulator plants concentrate. T. Livi3, M. L. Rivers4, M. A. Marcus5, R. L. Chaney6 and D. L. Sparks1 1 Plant and Soil Sciences investigated for A. murale exposed to metal co-contaminants. · A. murale was irrigated with Ni

  19. Metal hyperaccumulation in plants - Biodiversity prospecting for phytoremediation technology

    Microsoft Academic Search

    Majeti Narasimha Vara Prasad; Helena Maria De Oliveira Freitas

    2003-01-01

    The importance of biodiversity (below and above ground) is increasingly considered for the cleanup of the metal contaminated and polluted ecosystems. This subject is emerging as a cutting edge area of research gaining commercial significance in the contemporary field of environmental biotechnology. Several microbes, including mycorrhizal and non-mycorrhizal fungi, agricultural and vegetable crops, ornamentals, and wild metal hyperaccumulating plants are

  20. Selenium-Tolerant Diamondback Moth Disarms Hyperaccumulator Plant Defense

    Microsoft Academic Search

    John L. Freeman; Colin F. Quinn; Matthew A. Marcus; Sirine Fakra; Elizabeth A. H. Pilon-Smits

    2006-01-01

    Summary Background: Some plants hyperaccumulate the toxic element selenium (Se) to extreme levels, up to 1% of dry weight. The function of this intriguing phenomenon is obscure. Results: Here, we show that the Se in the hyperaccumu- lator prince's plume (Stanleya pinnata) protects it from caterpillar herbivory because of deterrence and toxicity. In its natural habitat, however, a newly discovered

  1. RESEARCH ARTICLE Open Access Selenium hyperaccumulation offers protection

    E-print Network

    of Se in the Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus against two cell disrupting (Tetranychus urticae). Results: Astragalus bisulcatus and S. pinnata with high Se concentrations (greater than. bisulcatus and S. pinnata plants rather than high-Se plants. Spider mite populations on A. bisulcatus

  2. Selenium hyperaccumulation offers protection from cell disruptor herbivores

    PubMed Central

    2010-01-01

    Background Hyperaccumulation, the rare capacity of certain plant species to accumulate toxic trace elements to levels several orders of magnitude higher than other species growing on the same site, is thought to be an elemental defense mechanism against herbivores and pathogens. Previous research has shown that selenium (Se) hyperaccumulation protects plants from a variety of herbivores and pathogens. Selenium hyperaccumulating plants sequester Se in discrete locations in the leaf periphery, making them potentially more susceptible to some herbivore feeding modes than others. In this study we investigate the protective function of Se in the Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus against two cell disrupting herbivores, the western flower thrips (Frankliniella occidentalis) and the two-spotted spider mite (Tetranychus urticae). Results Astragalus bisulcatus and S. pinnata with high Se concentrations (greater than 650 mg Se kg-1) were less subject to thrips herbivory than plants with low Se levels (less than 150 mg Se kg-1). Furthermore, in plants containing elevated Se levels, leaves with higher concentrations of Se suffered less herbivory than leaves with less Se. Spider mites also preferred to feed on low-Se A. bisulcatus and S. pinnata plants rather than high-Se plants. Spider mite populations on A. bisulcatus decreased after plants were given a higher concentration of Se. Interestingly, spider mites could colonize A. bisulcatus plants containing up to 200 mg Se kg-1 dry weight, concentrations which are toxic to many other herbivores. Selenium distribution and speciation studies using micro-focused X-ray fluorescence (?XRF) mapping and Se K-edge X-ray absorption spectroscopy revealed that the spider mites accumulated primarily methylselenocysteine, the relatively non-toxic form of Se that is also the predominant form of Se in hyperaccumulators. Conclusions This is the first reported study investigating the protective effect of hyperaccumulated Se against cell-disrupting herbivores. The finding that Se protected the two hyperaccumulator species from both cell disruptors lends further support to the elemental defense hypothesis and increases the number of herbivores and feeding modes against which Se has shown a protective effect. Because western flower thrips and two-spotted spider mites are widespread and economically important herbivores, the results from this study also have potential applications in agriculture or horticulture, and implications for the management of Se-rich crops. PMID:20799959

  3. Identification of Endogenous Gibberellins in the Winter Annual Weed Thlaspi arvense L

    PubMed Central

    Metzger, James D.; Mardaus, Marcia C.

    1986-01-01

    Eleven endogenous gibberellins (GAs) were identified by combined gas chromatography-mass spectrometry in purified extracts from shoots of field pennycress (Thlaspi arvense L.): GA1,9,12,15,19,20,24,29,44,51,53. Traces of GA8 and GA25 were tentatively indicated by combined gas chromatography-mass spectrometry-selected ion monitoring. Comparison of the total ion current traces indicated that GA19 and GA44 were most abundant, while GA12,15,20,24,29,53 occurred in lesser amounts. Only small amounts of GA1,9,51 were present. The levels of GA8 and GA25 were barely detectable. Consideration of hydroxylation patterns of the ent-gibberellane ring structure indicates two families of GAs: one with a C-13 hydroxyl group (GA1,8,19,20,29,44,53) and another whose members are either nonhydroxylated (GA9,12,15,24,25) or lack a C-13 hydroxyl group (GA51). This suggests that in field pennycress there are two parallel pathways for GA metabolism with an early branch point from GA12: an early C-13 hydroxylation pathway, leading ultimately to GA1 and GA8 and a C-13 deoxy pathway culminating in the formation of GA9 and GA51. PMID:16664632

  4. Nickel Hyperaccumulation in the Serpentine Flora of Cuba

    Microsoft Academic Search

    R. D. REEVES; A. J. M. BAKER; A. BORHIDI; R. BERAZAÍN

    1999-01-01

    Extraordinary uptake (hyperaccumulation) of nickel (Ni), reaching concentrations of 0.1–5.0%, about 1000-times greater than those usually found in flowering plants, has been reported over the period 1948–1996 in about 190 species that grow on Ni-rich serpentine soils derived from ultramafic rocks in various parts of the world. A recent study of the families Buxaceae and Euphorbiaceae identified a further 80

  5. Selenium-tolerant diamondback moth disarms hyperaccumulator plantdefense

    SciTech Connect

    Freeman, J.L.; Quinn, C.F.; Marcus, M.A.; Fakra, S.; Pilon-Smits,E.A.H.

    2006-11-20

    Background Some plants hyperaccumulate the toxic element selenium (Se) to extreme levels, up to 1% of dry weight. The function of this intriguing phenomenon is obscure. Results Here, we show that the Se in the hyperaccumulator prince's plume (Stanleya pinnata) protects it from caterpillar herbivory because of deterrence and toxicity. In its natural habitat, however, a newly discovered variety of the invasive diamondback moth (Plutella xylostella) has disarmed this elemental defense. It thrives on plants containing highly toxic Se levels and shows no oviposition or feeding deterrence, in contrast to related varieties. Interestingly, a Se-tolerant wasp (Diadegma insulare) was found to parasitize the tolerant moth. The insect's Se tolerance mechanism was revealed by X-ray absorption spectroscopy and liquid chromatography--mass spectroscopy, which showed that the Se-tolerant moth and its parasite both accumulate methylselenocysteine, the same form found in the hyperaccumulator plant, whereas related sensitive moths accumulate selenocysteine. The latter is toxic because of its nonspecific incorporation into proteins. Indeed, the Se-tolerant diamondback moth incorporated less Se into protein. Additionally, the tolerant variety sequestered Se in distinct abdominal areas, potentially involved in detoxification and larval defense to predators. Conclusions Although Se hyperaccumulation protects plants from herbivory by some invertebrates, it can give rise to the evolution of unique Se-tolerant herbivores and thus provide a portal for Se into the local ecosystem. In a broader context, this study provides insight into the possible ecological implications of using Se-enriched crops as a source of anti-carcinogenic selenocompounds and for the remediation of Se-polluted environments.

  6. Effects of cold-pressing and seed cooking on functional properties of protein in pennycress (Thlaspi arvense L.) seed and press cakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current interest in pennycress (Thlaspi arvense L.) comes from its seed oil, which is being evaluated for biofuel production. The seed also has notable protein content (27% moisture-free, oil-free basis). The effects of oil processing conditions on functionality of pennycress seed proteins were dete...

  7. Heavy metal concentrations in plants growing on a copper mine spoil in the Grand Canyon, Arizona. [Thlaspi montanum; Phlox austromontana; Juniperus osteosperma

    Microsoft Academic Search

    R. J. Hobbs; B. Streit

    1986-01-01

    Concentrations of metals including manganese, nickel, copper and zinc were measured in soil from a copper mine spoil heap in the Grand Canyon, Arizona, and in three plant species growing on the spoil. The soil had high concentrations of available copper and zinc, and the herbaceous perennial Thlaspi montanum var fendleri contained amounts of Ni, Cu and Zn in direct

  8. Absorption of foliar-applied arsenic by the arsenic hyperaccumulating fern (Pteris vittata L.)

    E-print Network

    Ma, Lena

    in the phytoremediation of groundwater contaminated with arsenic. D 2004 Elsevier B.V. All rights reserved. KeywordsAbsorption of foliar-applied arsenic by the arsenic hyperaccumulating fern (Pteris vittata L brake fern (Pteris vittata L.), a hyperaccumulator of arsenic, a carcinogenic metalloid, was proficient

  9. Uptake and Cellular Compartmentalization of Metals from the Rhizosphere by Hyperaccumulating Plants: A Real Time

    E-print Network

    Sparks, Donald L.

    Uptake and Cellular Compartmentalization of Metals from the Rhizosphere by Hyperaccumulating Plants in hyperaccumulating plants. Previous attempts to establish the path of metal ingress into plant tissues have suffered-vivo response of plants to heavy metals in the rhizosphere. We first focused on characterizing the species

  10. THE DEFENSIVE ROLE OF NI HYPERACCUMULATION BY PLANTS: A FIELD EXPERIMENT1

    Microsoft Academic Search

    SCOTT N. MARTENS; ROBERT S. BOYD

    Hyperaccumulation of Ni by plants is hypothesized to function as an elemental defense against herbivores and pathogens. Laboratory experiments have documented toxic effects to herbivores consuming high-Ni plant tissues, but this paper reports the first experiment to examine the defensive effectiveness of Ni hyperaccumulation under field conditions. The experiment was conducted at an ultramafic soil site naturally inhabited by the

  11. Selenium Distribution and Speciation in the Hyperaccumulator Astragalus bisulcatus and Associated

    E-print Network

    Selenium Distribution and Speciation in the Hyperaccumulator Astragalus bisulcatus and Associated hyperaccumulator Astragalus bisulcatus was collected in its natural seleniferous habitat, and x-ray fluorescence example is Astragalus bisulcatus (two-grooved milkvetch), which is capable of accumu- lating Se to levels

  12. Interactions of selenium hyperaccumulators and nonaccumulators during cocultivation on seleniferous or

    E-print Network

    . · Hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and nonaccumulators Astragalus drummondii and Stanleya: Astragalus, hyperaccumulation, phytoenrichment, plant­plant interactions, selenium, Stanleya. Summary accumulated relatively more C-Se-C and less selenate when growing adjacent to S. pinnata. Both

  13. Rhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns.

    PubMed

    Gonzaga, Maria Isidória Silva; Ma, Lena Qying; Santos, Jorge Antônio Gonzaga; Matias, Maria Iraildes Silva

    2009-08-01

    Better understanding of the processes controlling arsenic bioavailability in the rhizosphere is important to enhance plant arsenic accumulation by hyperaccumulators. This greenhouse experiment was conducted to evaluate the chemical characteristics of the rhizosphere of two arsenic hyperaccumulators Pterisvittata and Pterisbiaurita. They were grown for 8 weeks in rhizopots containing arsenic-contaminated soils (153 and 266 mg kg(-1) arsenic). Bulk and rhizosphere soil samples were analyzed for water-soluble As (WS-As) and P (WS-P), pH, and dissolved organic carbon (DOC). Comparing the two plants, P.vittata was more tolerant to arsenic and more efficient in arsenic accumulation than P.biaurita, with the highest frond arsenic being 3222 and 2397 mg kg(-1). Arsenic-induced root exudates reduced soil pH (by 0.74-0.92 units) and increased DOC concentrations (2-3 times) in the rhizosphere, resulting in higher WS-P (2.6-3.8 times higher) compared to the bulk soil. Where there was no difference in WS-As between the rhizosphere and bulk soil in soil-153 for both plants, WS-As in the rhizosphere was 20-40% higher than those in bulk soil in soil-266, indicating that the rate of As-solubilization was more rapid than that of plant uptake. The ability to solubilize arsenic via root exudation in the rhizosphere and the ability to accumulate more P under arsenic stress may have contributed to the efficiency of hyperaccumulator plants in arsenic accumulation. PMID:19476972

  14. Molecular mechanisms of selenium tolerance and hyperaccumulation in Stanleya pinnata.

    PubMed

    Freeman, John L; Tamaoki, Masanori; Stushnoff, Cecil; Quinn, Colin F; Cappa, Jennifer J; Devonshire, Jean; Fakra, Sirine C; Marcus, Matthew A; McGrath, Steve P; Van Hoewyk, Doug; Pilon-Smits, Elizabeth A H

    2010-08-01

    The molecular mechanisms responsible for selenium (Se) tolerance and hyperaccumulation were studied in the Se hyperaccumulator Stanleya pinnata (Brassicaceae) by comparing it with the related secondary Se accumulator Stanleya albescens using a combination of physiological, structural, genomic, and biochemical approaches. S. pinnata accumulated 3.6-fold more Se and was tolerant to 20 microm selenate, while S. albescens suffered reduced growth, chlorosis and necrosis, impaired photosynthesis, and high levels of reactive oxygen species. Levels of ascorbic acid, glutathione, total sulfur, and nonprotein thiols were higher in S. pinnata, suggesting that Se tolerance may in part be due to increased antioxidants and up-regulated sulfur assimilation. S. pinnata had higher selenocysteine methyltransferase protein levels and, judged from liquid chromatography-mass spectrometry, mainly accumulated the free amino acid methylselenocysteine, while S. albescens accumulated mainly the free amino acid selenocystathionine. S. albescens leaf x-ray absorption near-edge structure scans mainly detected a carbon-Se-carbon compound (presumably selenocystathionine) in addition to some selenocysteine and selenate. Thus, S. albescens may accumulate more toxic forms of Se in its leaves than S. pinnata. The species also showed different leaf Se sequestration patterns: while S. albescens showed a diffuse pattern, S. pinnata sequestered Se in localized epidermal cell clusters along leaf margins and tips, concentrated inside of epidermal cells. Transcript analyses of S. pinnata showed a constitutively higher expression of genes involved in sulfur assimilation, antioxidant activities, defense, and response to (methyl)jasmonic acid, salicylic acid, or ethylene. The levels of some of these hormones were constitutively elevated in S. pinnata compared with S. albescens, and leaf Se accumulation was slightly enhanced in both species when these hormones were supplied. Thus, defense-related phytohormones may play an important signaling role in the Se hyperaccumulation of S. pinnata, perhaps by constitutively up-regulating sulfur/Se assimilation followed by methylation of selenocysteine and the targeted sequestration of methylselenocysteine. PMID:20498337

  15. Genetic and Molecular Dissection of Arsenic Hyperaccumulation in the fern Pteris vittata.

    SciTech Connect

    Jo Ann Banks; David Salt

    2008-04-04

    Pteris vittata is a fern that is extraordinary in its ability to tolerate hyperaccumulate high levels of arsenic (As). The goals of the proposed research, to identify the genes that are necessary for As hyperaccumulation in P. vittata using molecular and genetic approaches and to understand the physiology of arsenic uptake and distribution in the living plant, were accomplished during the funding period. The genes that have been identified may ultimately enable the engineering or selection of other plants capable of As hyperaccumulation. This is important for the phytoremediation of arsenic-contaminated soils in areas where P. vittata cannot grow.

  16. Youngia erythrocarpa, a newly discovered cadmium hyperaccumulator plant.

    PubMed

    Lin, Lijin; Ning, Bo; Liao, Ming'an; Ren, Yajun; Wang, Zhihui; Liu, Yingjie; Cheng, Ji; Luo, Li

    2015-01-01

    The farmland weed Youngia erythrocarpa has been found to have the basic characteristics of a cadmium (Cd) hyperaccumulator. This study carried out preliminary and further Cd concentration gradient experiments and field experiment using Y. erythrocarpa to confirm this fact. The results showed that the biomass and resistance coefficient of Y. erythrocarpa decreased, but the root/shoot ratio and the Cd content in roots and shoots increased with the increase in soil Cd concentration. The Cd content in shoots of Y. erythrocarpa exceeded 100 mg/kg when the soil Cd concentration was 25 mg/kg in the two concentration gradient experiments, up to the maxima of 293.25 and 317.87 mg/kg at 100 mg/kg soil Cd. Both the bioconcentration factor of the shoots and the translocation factor exceeded 1 in all Cd treatments. In the field experiment, the total Cd extraction by shoots was 0.934-0.996 mg/m(2) at soil Cd levels of 2.04-2.89 mg/kg. Therefore, Y. erythrocarpa is a Cd hyperaccumulator that could be used to remediate Cd-contaminated farmland soil efficiently. PMID:25504193

  17. Nopalea cochenillifera, a potential chromium (VI) hyperaccumulator plant.

    PubMed

    Adki, Vinayak S; Jadhav, Jyoti P; Bapat, Vishwas A

    2013-02-01

    Hexavalant chromium [Cr(VI)] tolerance and accumulation in in vitro grown Nopalea cochenillifera Salm. Dyck. plants was investigated. A micropropagation protocol was establish for a rapid multiplication of N. cochenillifera and [Cr(VI)] tolerance and accumulation was studied in in vitro grown cultures. Cr concentration was estimated by atomic absorption spectroscopy in roots and shoots to confirm plant's hyperaccumulation capacity. Plants showed tolerance up to 100 ?M K(2)Cr(2)O(7) without any significant changes in root growth after 16 days treatment; whereas, chlorophyll content in plants treated with 1 and 10 ?M K(2)Cr(2)O(7) were not so different than the control plant. The levels of lipid peroxidation and protein oxidation increased significantly (p < 0.01) with increasing concentration of chromium. Exposures of N. cochenillifera to lower concentrations of K(2)Cr(2)O(7) (? 10 ?M) induced catalase (CAT) and superoxide dismutase (SOD) significantly (p < 0.001) but higher concentrations of K(2)Cr(2)O(7) (>100 ?M) inhibited the activities of CAT and SOD. Roots accumulated a maximum of 25,263.396 ± 1,722.672 mg Cr Kg(-1) dry weight (DW); while the highest concentration of Cr in N. cochenillifera shoots was 705.714 ± 32.324 mg Cr Kg(-1) DW. N. cochenillifera could be a prospective hyperaccumulator plant of Cr(VI) and a promising candidate for phytoremediation purposes. PMID:22914913

  18. Tissue Fractions of Cadmium in Two Hyperaccumulating Jerusalem Artichoke Genotypes

    PubMed Central

    Long, Xiaohua; Ni, Ni; Liu, Zhaopu; Rengel, Zed; Jiang, Xin; Shao, Hongbo

    2014-01-01

    In order to investigate the mechanisms in two Jerusalem artichoke (Helianthus tuberosus L.) genotypes that hyperaccumulate Cd, a sand-culture experiment was carried out to characterize fractionation of Cd in tissue of Cd-hyperaccumulating genotypes NY2 and NY5. The sequential extractants were: 80%?v/v ethanol (FE), deionized water (FW), 1?M NaCl (FNaCl), 2%?v/v acetic acid (FAcet), and 0.6?M HCl (FHCl). After 20 days of treatments, NY5 had greater plant biomass and greater Cd accumulation in tissues than NY2. In both genotypes the FNaCl fraction was the highest in roots and stems, whereas the FAcet and FHCl fractions were the highest in leaves. With an increase in Cd concentration in the culture solution, the content of every Cd fraction also increased. The FW and FNaCl ratios in roots were lower in NY5 than in NY2, while the amount of other Cd forms was higher. It implied that, in high accumulator, namely, NY5, the complex of insoluble phosphate tends to be shaped more easily which was much better for Cd accumulation. Besides, translocation from plasma to vacuole after combination with protein may be one of the main mechanisms in Cd-accumulator Jerusalem artichoke genotypes. PMID:24883399

  19. Rhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns Maria Isidria Silva Gonzaga a,b

    E-print Network

    Ma, Lena

    Rhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns Maria Isidória Silva, such as fern species in the Pteris genus (Ma et al., 2001; Srivastava et al., 2006), makes phytoextraction

  20. Microbeam methodologies as powerful tools in manganese hyperaccumulation research: present status and future directions.

    PubMed

    Fernando, Denise R; Marshall, Alan; Baker, Alan J M; Mizuno, Takafumi

    2013-01-01

    Microbeam studies over the past decade have garnered unique insight into manganese (Mn) homeostasis in plant species that hyperaccumulate this essential mineral micronutrient. Electron- and/or proton-probe methodologies employed to examine tissue elemental distributions have proven highly effective in illuminating excess foliar Mn disposal strategies, some apparently unique to Mn hyperaccumulating plants. When applied to samples prepared with minimal artefacts, these are powerful tools for extracting true 'snapshot' data of living systems. For a range of reasons, Mn hyperaccumulation is particularly suited to in vivo interrogation by this approach. Whilst microbeam investigation of metallophytes is well documented, certain methods originally intended for non-biological samples are now widely applied in biology. This review examines current knowledge about Mn hyperaccumulators with reference to microbeam methodologies, and discusses implications for future research into metal transporters. PMID:23970891

  1. Phytoextraction process optimization: characterization of the soil bacteria flora associated to the hyperaccumulator Arabidopsis

    E-print Network

    Paris-Sud XI, Université de

    for the treatment of contaminated sites. Among these, phytoextraction based on hyperaccumulator plants Phytoextraction, a microbial-assisted plant technology usable for the treatment of contaminated sites, exploits elements Abstract Phytotechnologies are microbial-assisted techniques that use living plants

  2. Molecular Dissection of The Cellular Mechanisms Involved In Nickel Hyperaccumulation in Plants

    SciTech Connect

    David E. Salt

    2002-04-08

    Hyperaccumulator plant species are able to accumulate between 1-5% of their biomass as metal. However, these plants are often small, slow growing, and do not produce a high biomass. Phytoextraction, a cost-effective, in situ, plant based approach to soil remediation takes advantage of the remarkable ability of hyperaccumulating plants to concentrate metals from the soil and accumulate them in their harvestable, above-ground tissues. However, to make use of the valuable genetic resources identified in metal hyperaccumulating species, it will be necessary to transfer this material to high biomass rapidly growing crop plants. These plants would then be ideally suited to the phytoremediation process, having the ability to produce large amount of metal-rich plant biomass for rapid harvest and soil cleanup. Although progress is being made in understanding the genetic basis of metal hyperaccumulation a more complete understanding will be necessary before we can take full advantage of the genetic potential of these plants.

  3. ARSENIC UPTAKE BY TWO HYPERACCUMULATOR FERNS FROM FOUR ARSENIC CONTAMINATED SOILS

    E-print Network

    Ma, Lena

    . vittata was overall a better candidate for phytoremediation of arsenic contaminated soils. Keywords in the environment (Smedley et al., 1996). Phytoremediation, the use of hyperaccumulating plants to remediate As con

  4. Microbeam methodologies as powerful tools in manganese hyperaccumulation research: present status and future directions

    PubMed Central

    Fernando, Denise R.; Marshall, Alan; Baker, Alan J. M.; Mizuno, Takafumi

    2013-01-01

    Microbeam studies over the past decade have garnered unique insight into manganese (Mn) homeostasis in plant species that hyperaccumulate this essential mineral micronutrient. Electron- and/or proton-probe methodologies employed to examine tissue elemental distributions have proven highly effective in illuminating excess foliar Mn disposal strategies, some apparently unique to Mn hyperaccumulating plants. When applied to samples prepared with minimal artefacts, these are powerful tools for extracting true ‘snapshot’ data of living systems. For a range of reasons, Mn hyperaccumulation is particularly suited to in vivo interrogation by this approach. Whilst microbeam investigation of metallophytes is well documented, certain methods originally intended for non-biological samples are now widely applied in biology. This review examines current knowledge about Mn hyperaccumulators with reference to microbeam methodologies, and discusses implications for future research into metal transporters. PMID:23970891

  5. Selenium Hyperaccumulator Plants Stanleya pinnata and Astragalus bisulcatus Are Colonized by Se-Resistant, Se-

    E-print Network

    Selenium Hyperaccumulator Plants Stanleya pinnata and Astragalus bisulcatus Are Colonized by Se Astragalus bisulcatus and Stanleya pinnata. Selenium accumulation, localization and speciation were: Bruchidae) and seed chalcid larvae (Bruchophagus mexicanus, Hymenoptera: Eurytomidae). Stanleya pinnata

  6. Sulfur-selenium-molybdenum interactions distinguish selenium hyperaccumulator Stanleya pinnata from non-hyperaccumulator Brassica juncea (Brassicaceae).

    PubMed

    Harris, Jonathan; Schneberg, Kathryn A; Pilon-Smits, Elizabeth A H

    2014-02-01

    Long-term sulfate, selenate and molybdate accumulation and translocation were investigated in two ecotypes of Stanleya pinnata and non-hyperaccumulator Brassica juncea under different levels of applied sulfate and selenate. Morphological differences were observed between the ecotypes of S. pinnata, but few differences in selenium (Se) and sulfur (S) accumulation were measured. Se-to-S ratios were nearly identical between the ecotypes under all treatments. When compared with B. juncea, several unique trends were observed in the hyperaccumulators. While both S. pinnata ecotypes showed no significant effect on Se content of young leaves when the supplied sulfate in the growth medium was increased tenfold (from 0.5 to 5 mM), the Se levels in B. juncea decreased 4- to 12-fold with increased sulfate in the growth medium. Furthermore, S. pinnata’s S levels decreased slightly with high levels of supplied Se, suggesting competitive inhibition of uptake, while B. juncea showed higher S levels with increasing Se, possibly due to up-regulation of sulfate transporters. Both ecotypes of S. pinnata showed much larger Se concentrations in young leaves, while B. juncea showed slightly higher levels of Se in older leaves relative to young. Molybdenum (Mo) levels significantly decreased in S. pinnata with increasing sulfate and selenate in the medium; B. juncea did not show the same trends. These findings support the hypothesis that S. pinnata contains a modified sulfate transporter with a higher specificity for selenate. PMID:24233101

  7. Root foraging for zinc and cadmium requirement in the Zn\\/Cd hyperaccumulator plant Sedum alfredii

    Microsoft Academic Search

    Fengjie Liu; Yetao Tang; Ruijun Du; Haiyan Yang; Qitang Wu; Rongliang Qiu

    2010-01-01

    Positive root response to metals may enhance metal accumulation for greater requirement in hyperaccumulators. The effects\\u000a of spatially heterogeneous Zn\\/Cd addition on root allocation, metal accumulation, and growth of the Zn\\/Cd hyperaccumulator\\u000a Sedum alfredii were assessed in a pot experiment. Young shoots of S. alfredii were grown with or without supplied Zn\\/Cd. Two concentrations were used of each metal, and

  8. Fertilizer amendment for improving the phytoextraction of cadmium by a hyperaccumulator Rorippa globosa (Turcz.) Thell

    Microsoft Academic Search

    Shuhe Wei; Jiangong Zhu; Qixing X. Zhou; Jie Zhan

    Purpose  Two main pathways of phytoremediation of heavy metal-contaminated soils are phytostabilization and phytoextraction. Some soil\\u000a amendments can strengthen phytostabilization or phytoextraction through either reducing heavy metal bioavailability in soil\\u000a or increasing the heavy metal accumulation capacity of the hyperaccumulator (enhancing heavy metal concentration or shoot\\u000a biomass of the hyperaccumulator). Urea and chicken manure are often used as fertilizers. This research

  9. Evolutionary lineages of nickel hyperaccumulation and systematics in European Alysseae (Brassicaceae): evidence from nrDNA sequence data

    PubMed Central

    Cecchi, Lorenzo; Gabbrielli, Roberto; Arnetoli, Miluscia; Gonnelli, Cristina; Hasko, Agim; Selvi, Federico

    2010-01-01

    Background and Aims Nickel (Ni) hyperaccumulation is a rare form of physiological specialization shared by a small number of angiosperms growing on ultramafic soils. The evolutionary patterns of this feature among European members of tribe Alysseae (Brassicaceae) are investigated using a phylogenetic approach to assess relationships among Ni hyperaccumulators at the genus, species and below-species level. Methods Internal transcribed spacer (ITS) sequences were generated for multiple accessions of Alysseae. Phylogenetic trees were obtained for the genera of the tribe and Alyssum sect. Odontarrhena. All accessions and additional herbarium material were tested for Ni hyperaccumulation with the dimethylglyoxime colorimetric method. Key Results Molecular data strongly support the poorly known hyperaccumulator endemic Leptoplax (Peltaria) emarginata as sister to hyperaccumulator species of Bornmuellera within Alysseae. This is contrary to current assumptions of affinity between L. emarginata and the non-hyperaccumulator Peltaria in Thlaspideae. The lineage Bornmuellera–Leptoplax is, in turn, sister to the two non-hyperaccumulator Mediterranean endemics Ptilotrichum rupestre and P. cyclocarpum. Low ITS sequence variation was found within the monophyletic Alyssum sect. Odontarrhena and especially in A. murale sensu lato. Nickel hyperaccumulation was not monophyletic in any of three main clades retrieved, each consisting of hyperaccumulators and non-hyperaccumulators of different geographical origin. Conclusions Nickel hyperaccumulation in Alysseae has a double origin, but it did not evolve in Thlaspideae. In Bornmuellera–Leptoplax it represents an early synapomorphy inherited from an ancestor shared with the calcicolous, sister clade of Mediterranean Ptilotrichum. In Alyssum sect. Odontarrhena it has multiple origins even within the three European clades recognized. Lack of geographical cohesion suggests that accumulation ability has been lost or gained over the different serpentine areas of south Europe through independent events of microevolutionary adaptation and selection. Genetic continuity and strong phenotypic plasticity in the A. murale complex call for a reduction of the number of Ni hyperaccumulator taxa formally recognized. PMID:20724306

  10. Heavy metal tolerance in metal hyperaccumulator plant, Salvinia natans.

    PubMed

    Dhir, B; Srivastava, S

    2013-06-01

    Metal tolerance capacity of Salvinia natans, a metal hyperaccumulator, was evaluated. Plants were exposed to 10, 30 and 50 mg L?¹ of Zn, Cd, Co, Cr, Fe, Cu, Pb, and Ni. Plant biomass, photosynthetic efficiency, quantum yield, photochemical quenching, electron transport rate and elemental (%C, H and N) constitution remained unaffected in Salvinia exposed to 30 mg L?¹ of heavy metals, except for Cu and Zn exposed plants, where significant reductions were noted in some of the measured parameters. However, a significant decline was noted in most of the measured parameters in plants exposed to 50 mg L?¹ of metal concentration. Results suggest that Salvinia has fairly high levels of tolerance to all the metals tested, but the level of tolerance varied from metal to metal. PMID:23553503

  11. Selenium distribution and speciation in the hyperaccumulator Astragalus bisulcatus and associated ecological partners.

    PubMed

    Valdez Barillas, José R; Quinn, Colin F; Freeman, John L; Lindblom, Stormy D; Fakra, Sirine C; Marcus, Matthew A; Gilligan, Todd M; Alford, Élan R; Wangeline, Ami L; Pilon-Smits, Elizabeth A H

    2012-08-01

    The goal of this study was to investigate how plant selenium (Se) hyperaccumulation may affect ecological interactions and whether associated partners may affect Se hyperaccumulation. The Se hyperaccumulator Astragalus bisulcatus was collected in its natural seleniferous habitat, and x-ray fluorescence mapping and x-ray absorption near-edge structure spectroscopy were used to characterize Se distribution and speciation in all organs as well as in encountered microbial symbionts and herbivores. Se was present at high levels (704-4,661 mg kg(-1) dry weight) in all organs, mainly as organic C-Se-C compounds (i.e. Se bonded to two carbon atoms, e.g. methylselenocysteine). In nodule, root, and stem, up to 34% of Se was found as elemental Se, which was potentially due to microbial activity. In addition to a nitrogen-fixing symbiont, the plants harbored an endophytic fungus that produced elemental Se. Furthermore, two Se-resistant herbivorous moths were discovered on A. bisulcatus, one of which was parasitized by a wasp. Adult moths, larvae, and wasps all accumulated predominantly C-Se-C compounds. In conclusion, hyperaccumulators live in association with a variety of Se-resistant ecological partners. Among these partners, microbial endosymbionts may affect Se speciation in hyperaccumulators. Hyperaccumulators have been shown earlier to negatively affect Se-sensitive ecological partners while apparently offering a niche for Se-resistant partners. Through their positive and negative effects on different ecological partners, hyperaccumulators may influence species composition and Se cycling in seleniferous ecosystems. PMID:22645068

  12. Characterization of dissolved organic matter in the rhizosphere of hyperaccumulator Sedum alfredii and its effect on the mobility of zinc

    E-print Network

    Sparks, Donald L.

    and its effect on the mobility of zinc Tingqiang Li a,b, , Zhenghao Xu a , Xuan Han a , Xiaoe Yang Available online 3 April 2012 Keywords: Complexation Dissolved organic matter Hyperaccumulator Mobility Zinc-hyperaccumulating ecotype (NHE) of Sedum alfredii and its effects on the mobility of zinc (Zn). DOM was fractionated using

  13. THE EFFECT OF THE PH OF PH BUFFERED NUTRIENT SOLUTIONS ON NICKEL HYPERACCUMULATION BY ALYSSUM CORSICUM AND BERKHEYA CODDII

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is hypothesized that plant hyperaccumulation of Ni evolved as a defense mechanism against diseases and insects. Two hyperaccumulators, Alyssum corsicum and Berkheya coddii, were compared to cabbage (Brassica oleracea) grown in MES-HEPES buffered nutrient solutions and maintained at four pH levels...

  14. Soil and Water Science Department University of Florida Understanding and Enhancement of Arsenic Hyperaccumulation by a Fern Plant

    E-print Network

    Ma, Lena

    Hyperaccumulation by a Fern Plant Ma, L.Q., D. Sylvia, Y. Cai, K. Downum and J.-F. Gaillard 9/2001 to 8/2004 Arsenic discovered the only known arsenic hyperaccumulating plant, Brake fern, which accumulates >2% arsenic in its objective of this research is to understand and enhance arsenic uptake by Brake fern, with the ultimate goal

  15. Using Chelator-Buffered Nutrient Solutions to Induce Ni-Deficiency in the Ni-Hyperaccumulator Alyssum murale

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ni is essential for all plants due to its role in urease. Many Alyssum species are known to hyperaccumulate Ni to over 20 g kg-1 dry weight (DW) while normal plants require only about 0.1 mg kg-1 DW. As part of our research on Ni hyperaccumulation by plants, we conducted experiments to measure the...

  16. Low molecular weight thiols in arsenic hyperaccumulator Pteris vittata upon exposure to arsenic and other trace elements

    E-print Network

    Ma, Lena

    Low molecular weight thiols in arsenic hyperaccumulator Pteris vittata upon exposure to arsenic; accepted 25 September 2003 ``Capsule'': Arsenic induces synthesis of low molecular weight thiols in the arsenic hyperaccumulator Pteris vittata. Abstract Low molecular weight thiol-containing compounds have

  17. Interactive effects of Cd and PAHs on contaminants removal from co-contaminated soil planted with hyperaccumulator plant Sedum alfredii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil contamination by multiple organic and inorganic contaminants is common but its remediation by hyperaccumulator plants is rarely reported. The growth of a cadmium (Cd) hyperaccumulator Sedum alfredii and removal of contaminants from Cd and polycyclic aromatic hydrocarbons(PAHs) co-contaminated s...

  18. Molecular mechanisms of selenium tolerance and hyperaccumulation in Stanleya pinnata John L. Freeman1,2,3

    E-print Network

    2 Title: Molecular mechanisms of selenium tolerance and hyperaccumulation in Stanleya pinnata studied in the Se hyperaccumulator Stanleya pinnata (Brassicaceae) by comparing it to the related and biochemical approaches. S. pinnata accumulated 3.6-fold more Se and was tolerant to 20 µM selenate while S

  19. Evolution of selenium hyperaccumulation in Stanleya (Brassicaceae) as inferred from phylogeny, physiology and X-ray microprobe analysis.

    PubMed

    Cappa, Jennifer J; Yetter, Crystal; Fakra, Sirine; Cappa, Patrick J; DeTar, Rachael; Landes, Corbett; Pilon-Smits, Elizabeth A H; Simmons, Mark P

    2015-01-01

    Past studies have identified herbivory as a likely selection pressure for the evolution of hyperaccumulation, but few have tested the origin(s) of hyperaccumulation in a phylogenetic context. We focused on the evolutionary history of selenium (Se) hyperaccumulation in Stanleya (Brassicaceae). Multiple accessions were collected for all Stanleya taxa and two outgroup species. We sequenced four nuclear gene regions and performed a phylogenetic analysis. Ancestral reconstruction was used to predict the states for Se-related traits in a parsimony framework. Furthermore, we tested the taxa for Se localization and speciation using X-ray microprobe analyses. True hyperaccumulation was found in three taxa within the S. pinnata/bipinnata clade. Tolerance to hyperaccumulator Se concentrations was found in several taxa across the phylogeny, including the hyperaccumulators. X-ray analysis revealed two distinct patterns of leaf Se localization across the genus: marginal and vascular. All taxa accumulated predominantly (65-96%) organic Se with the C-Se-C configuration. These results give insight into the evolution of Se hyperaccumulation in Stanleya and suggest that Se tolerance and the capacity to produce organic Se are likely prerequisites for Se hyperaccumulation in Stanleya. PMID:25262627

  20. The bacterial rhizobiome of hyperaccumulators: future perspectives based on omics analysis and advanced microscopy

    PubMed Central

    Visioli, Giovanna; D'Egidio, Sara; Sanangelantoni, Anna M.

    2015-01-01

    Hyperaccumulators are plants that can extract heavy metal ions from the soil and translocate those ions to the shoots, where they are sequestered and detoxified. Hyperaccumulation depends not only on the availability of mobilized metal ions in the soil, but also on the enhanced activity of metal transporters and metal chelators which may be provided by the plant or its associated microbes. The rhizobiome is captured by plant root exudates from the complex microbial community in the soil, and may colonize the root surface or infiltrate the root cortex. This community can increase the root surface area by inducing hairy root proliferation. It may also increase the solubility of metals in the rhizosphere and promote the uptake of soluble metals by the plant. The bacterial rhizobiome, a subset of specialized microorganisms that colonize the plant rhizosphere and endosphere, makes an important contribution to the hyperaccumulator phenotype. In this review, we discuss classic and more recent tools that are used to study the interactions between hyperaccumulators and the bacterial rhizobiome, and consider future perspectives based on the use of omics analysis and microscopy to study plant metabolism in the context of metal accumulation. Recent data suggest that metal-resistant bacteria isolated from the hyperaccumulator rhizosphere and endosphere could be useful in applications such as phytoextraction and phytoremediation, although more research is required to determine whether such properties can be transferred successfully to non-accumulator species. PMID:25709609

  1. Recent advances in the analysis of metal hyperaccumulation and hypertolerance in plants using proteomics

    PubMed Central

    DalCorso, Giovanni; Fasani, Elisa; Furini, Antonella

    2013-01-01

    Hyperaccumulator/hypertolerant plant species have evolved strategies allowing them to grow in metal-contaminated soils, where they accumulate high concentrations of heavy metals in their shoots without signs of toxicity. The mechanisms that allow enhanced metal uptake, root-to-shoot translocation and detoxification in these species are not fully understood. Complementary approaches such as transcriptomic-based DNA microarrays and proteomics have recently been used to gain insight into the molecular pathways evolved by metal hyperaccumulator/hypertolerant species. Proteomics has the advantage of focusing on the translated portion of the genome and it allows to analyze complex networks of proteins. This review discusses the recent analysis of metal hyperaccumulator/hypertolerant plant species using proteomics. Changes in photosynthetic proteins, sulfur, and glutathione metabolism, transport, biotic and xenobiotic defenses as well as the differential regulation of proteins involved in signaling and secondary metabolism are discussed in relation to metal hyperaccumulation. We also consider the potential contribution of several proteins to the hyperaccumulation phenotype. PMID:23898342

  2. A draft genome of field pennycress (Thlaspi arvense) provides tools for the domestication of a new winter biofuel crop.

    PubMed

    Dorn, Kevin M; Fankhauser, Johnathon D; Wyse, Donald L; Marks, M David

    2015-04-01

    Field pennycress (Thlaspi arvense L.) is being domesticated as a new winter cover crop and biofuel species for the Midwestern United States that can be double-cropped between corn and soybeans. A genome sequence will enable the use of new technologies to make improvements in pennycress. To generate a draft genome, a hybrid sequencing approach was used to generate 47 Gb of DNA sequencing reads from both the Illumina and PacBio platforms. These reads were used to assemble 6,768 genomic scaffolds. The draft genome was annotated using the MAKER pipeline, which identified 27,390 predicted protein-coding genes, with almost all of these predicted peptides having significant sequence similarity to Arabidopsis proteins. A comprehensive analysis of pennycress gene homologues involved in glucosinolate biosynthesis, metabolism, and transport pathways revealed high sequence conservation compared with other Brassicaceae species, and helps validate the assembly of the pennycress gene space in this draft genome. Additional comparative genomic analyses indicate that the knowledge gained from years of basic Brassicaceae research will serve as a powerful tool for identifying gene targets whose manipulation can be predicted to result in improvements for pennycress. PMID:25632110

  3. New approaches to facilitate rapid domestication of a wild plant to an oilseed crop: example pennycress (Thlaspi arvense L.).

    PubMed

    Sedbrook, John C; Phippen, Winthrop B; Marks, M David

    2014-10-01

    Oilseed crops are sources of oils and seed meal having a multitude of uses. While the domestication of soybean and rapeseed took extended periods of time, new genome-based techniques have ushered in an era where crop domestication can occur rapidly. One attractive target for rapid domestication is the winter annual plant Field Pennycress (Thlaspi arvense L.; pennycress; Brassicaceae). Pennycress grows widespread throughout temperate regions of the world and could serve as a winter oilseed-producing cover crop. If grown throughout the USA Midwest Corn Belt, for example, pennycress could produce as much as 840L/ha oils and 1470kg/ha press-cake annually on 16 million hectares of farmland currently left fallow during the fall through spring months. However, wild pennycress strains have inconsistent germination and stand establishment, un-optimized maturity for a given growth zone, suboptimal oils and meal quality for biofuels and food production, and significant harvest loss due to pod shatter. In this review, we describe the virtues and current shortcomings of pennycress and discuss how knowledge from studying Arabidopsis thaliana and other Brassicas, in combination with the advent of affordable next generation sequencing, can bring about the rapid domestication and improvement of pennycress and other crops. PMID:25219314

  4. Feasibility of using hyperaccumulating plants to bioremediate metal-contaminated soil

    SciTech Connect

    Kelly, R.J. [Dames and Moore, Sydney, New South Wales (Australia); Guerin, T.F. [Minenco Bioremediation Services, Bundoora, Victoria (Australia)

    1995-12-31

    A feasibility study was carried out to determine whether selected plants were capable of hyperaccumulating anthropogenic sources of metals found in soils from three contaminated sites. A trial was conducted using the previously reported hyperaccumulators, Armeria maritima (thrift), Impatiens balsamina (balsam), Alyssum saxatile (gold dust), and the control species, Brassica oleracea (cabbage). Although none of these plants showed any substantial hyperaccumulation of Cu, Zn, Pb, and Cd, it was established that there is an optimum period in the life-cycle of these plants in which the metal concentration reaches a maximum. This period was dependent on the metal, soil, and plant type. The current paper describes the data obtained for Zn and Cu uptake by thrift.

  5. Bioaccumulation of heavy metals by submerged macrophytes: looking for hyperaccumulators in eutrophic lakes.

    PubMed

    Xing, Wei; Wu, Haoping; Hao, Beibei; Huang, Wenmin; Liu, Guihua

    2013-05-01

    To directly select submerged macrophytes with high accumulation capability from the field, 24 eutrophic lakes along the middle and lower reaches of the Yangtze River were investigated in the study. These eutrophic lakes have large amounts of heavy metals in both water and sediments because of human activities. The results showed that Najas marina is a hyperaccumulator of As and Cd, Ceratophyllum demersum is a hyperaccumulator of Co, Cr, and Fe, and Vallisneria natans is a hyperaccumulator of Pb. Strong positive correlations were found between concentrations of heavy metals in tissues of submerged macrophytes, probably because of coaccumulation of heavy metals. However, for most heavy metals, no significant correlations were found between submerged macrophytes and their surrounding environments. In conclusion, N. marina, C. demersum, and V. natans are good candidate species for removing heavy metals from eutrophic lakes. PMID:23582178

  6. Selenium protects the hyperaccumulator Stanleya pinnata against black-tailed prairie dog herbivory in native seleniferous habitats.

    PubMed

    Freeman, John L; Quinn, Colin F; Lindblom, Stormy Dawn; Klamper, Erin M; Pilon-Smits, Elizabeth A H

    2009-06-01

    Elemental hyperaccumulation in plants is hypothesized to represent a plant defense mechanism. The objective of this study was to determine whether selenium (Se) hyperaccumulation offers plants long-term protection from the black-tailed prairie dog (Cynomys ludovicianus). Prairie dogs are a keystone species. The hyperaccumulator Stanleya pinnata (prince's plume) co-occurs with prairie dogs in seleniferous areas in the western United States. Stanleya pinnata plants pretreated with high or low Se concentrations were planted on two prairie dog towns with different levels of herbivory pressure, and herbivory of these plants was monitored over 2 years. Throughout this study, plants with elevated Se levels suffered less herbivory and survived better than plants with low leaf Se concentrations. This study indicates that the Se in hyperaccumulator S. pinnata protects the plant in its natural habitat from herbivory by the black-tailed prairie dog. The results from this study support the hypothesis that herbivory by prairie dogs or similar small mammals has been a contributing selection pressure for the evolution of plant Se hyperaccumulation in North America. This study is the first to test the ecological significance of hyperaccumulation over a long period in a hyperaccumulator's natural habitat. PMID:21628258

  7. The role of selenium in protecting plants against prairie dog herbivory: implications for the evolution of selenium hyperaccumulation.

    PubMed

    Quinn, Colin F; Freeman, John L; Galeas, Miriam L; Klamper, Erin M; Pilon-Smits, Elizabeth A H

    2008-03-01

    Some plants can hyperaccumulate the element selenium (Se) up to 10,000 mg Se kg(-1) dry weight. Hyperaccumulation has been hypothesized to defend against herbivory. In laboratory studies high Se levels protect plants from invertebrate herbivores and pathogens. However, field studies and mammalian herbivore studies that link Se accumulation to herbivory protection are lacking. In this study a combination of field surveys and manipulative field studies were carried out to determine whether plant Se accumulation in the field deters herbivory by black-tailed prairie dogs (Cynomys ludovicianus). The Se hyperaccumulator Astragalus bisulcatus (two-grooved milkvetch) occurs naturally on seleniferous soils in the Western USA, often on prairie dog colonies. Field surveys have shown that this Se hyperaccumulator is relatively abundant on some prairie dog colonies and suffers less herbivory than other forb species. This protection was likely owing to Se accumulation, as judged from subsequent manipulative field experiments. When given a choice between pairs of plants of the Se hyperaccumulator Stanleya pinnata (prince's plume) that were pretreated with or without Se, prairie dogs preferred to feed on the plants with low Se; the same results were obtained for the non-hyperaccumulator Brassica juncea (Indian mustard). Plants containing as little as 38 mg Se kg(-1) DW were protected from herbivory. Taken together these results shed light on the functional significance of Se hyperaccumulation and the possible selection pressures driving its evolution. They also have implications for the use of plants in Se phytoremediation, or as Se-fortified crops. PMID:18278517

  8. Foliar Mn accumulation in eastern Australian herbarium specimens: prospecting for ‘new’ Mn hyperaccumulators and potential applications in taxonomy

    PubMed Central

    Fernando, Denise R.; Guymer, Gordon; Reeves, Roger D.; Woodrow, Ian E.; Baker, Alan J.; Batianoff, George N.

    2009-01-01

    Background and Aims The analysis of herbarium specimens has previously been used to prospect for ‘new’ hyperaccumulators, while the use of foliar manganese (Mn) concentrations as a taxonomic tool has been suggested. On the basis of their geographic and taxonomic affiliations to known Mn hyperaccumulators, six eastern Australian genera from the Queensland Herbarium collection were sampled for leaf tissue analyses. Methods ICP-OES was used to measure Mn and other elemental concentrations in 47 species within the genera Austromyrtus, Lenwebbia, Gossia (Myrtaceae), Macadamia (Proteaceae), Maytenus and Denhamia (Celastraceae). Key Results The resulting data demonstrated (a) up to seven ‘new’ Mn hyperaccumulators, mostly tropical rainforest species; (b) that one of these ‘new’ Mn hyperaccumulators also had notably elevated foliar Ni concentrations; (c) evidence of an interrelationship between foliar Mn and Al uptake among the Macadamias; (d) considerable variability of Mn hyperaccumulation within Gossia; and (e) the possibility that Maytenus cunninghamii may include subspecies. Conclusions Gossia bamagensis, G. fragrantissima, G. sankowsiorum, G. gonoclada and Maytenus cunninghamii were identified as ‘new’ Mn hyperaccumulators, while Gossia lucida and G. shepherdii are possible ‘new’ Mn hyperaccumulators. Of the three Myrtaceae genera examined, Mn hyperaccumulation appears restricted to Gossia, supporting its recent taxonomic revision. In the context of this present investigation and existing information, a reassesment of the general definition of Mn hyperaccumulation may be warranted. Morphological variation of Maytenus cunninghamii at two extremities was consistent with variation in Mn accumulation, indicating two possible ‘new’ subspecies. Although caution should be exercised in interpreting the data, surveying herbarium specimens by chemical analysis has provided an effective means of assessing foliar Mn accumulation. These findings should be followed up by field studies. PMID:19211572

  9. Organic acids rather than histidine predominate in Ni chelation in Alyssum hyperaccumulator xylem exudate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A better understanding of Ni uptake mechanisms by hyperaccumulator plants is necessary to improve Ni uptake efficiency for phytoremediation technologies i.e. phytomining. It is known that an important aspect of Ni translocation involves Ni chelation with organic ligands. However, it is still not cle...

  10. Transcriptomic Analysis of Cadmium Stress Response in the Heavy Metal Hyperaccumulator Sedum alfredii Hance

    PubMed Central

    Yang, Xiaoe; Liu, Jian-Xiang

    2013-01-01

    The Sedum alfredii Hance hyperaccumulating ecotype (HE) has the ability to hyperaccumulate cadmium (Cd), as well as zinc (Zn) and lead (Pb) in above-ground tissues. Although many physiological studies have been conducted with these plants, the molecular mechanisms underlying their hyper-tolerance to heavy metals are largely unknown. Here we report on the generation of 9.4 gigabases of adaptor-trimmed raw sequences and the assembly of 57,162 transcript contigs in S. alfredii Hance (HE) shoots by the combination of Roche 454 and Illumina/Solexa deep sequencing technologies. We also have functionally annotated the transcriptome and analyzed the transcriptome changes upon Cd hyperaccumulation in S. alfredii Hance (HE) shoots. There are 110 contigs and 123 contigs that were up-regulated (Fold Change ?2.0) and down-regulated (Fold Change ?0.5) by chronic Cd treatment in S. alfredii Hance (HE) at q-value cutoff of 0.005, respectively. Quantitative RT-PCR was employed to compare gene expression patterns between S. alfredii Hance (HE) and non-hyperaccumulating ecotype (NHE). Our results demonstrated that several genes involved in cell wall modification, metal translocation and remobilization were more induced or constitutively expressed at higher levels in HE shoots than that in NHE shoots in response to Cd exposure. Together, our study provides large-scale expressed sequence information and genome-wide transcriptome profiling of Cd responses in S. alfredii Hance (HE) shoots. PMID:23755133

  11. Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern)

    E-print Network

    Ma, Lena

    Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern) Weihua Zhanga in arsenic detoxification. Abstract Pteris vittata (Chinese brake fern) has potential for phytoremediation to be a supplement. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Pteris vittata; Chinese brake fern; Thiols

  12. The Metal Hyperaccumulator Alyssum murale Uses Nitrogen and Oxygen Donor Ligands for Ni Transport and Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Kotodesh genotype of the nickel (Ni) hyperaccumulator Alyssum murale was examined to determine the compartmentalization and internal speciation of Ni, and other elements, in an effort to ascertain the mechanism used by this plant to tolerate extremely high shoot Ni concentrations. Plants were g...

  13. Abstract Arsenic hyperaccumulator Pteris vittata L. (Chinese brake fern) grows well in arsenic-contami-

    E-print Network

    Ma, Lena

    Abstract Arsenic hyperaccumulator Pteris vittata L. (Chinese brake fern) grows well in arsenic isomerase (TPI) specific activities than that found in E. coli XL-1 Blue and had a 42 kD fusion protein or indirectly functioning as an arsenate reductase. When E. coli tpi gene was expressed in the same vector

  14. THE PLANT-SOIL INTERFACE: SOIL NICKEL SPECIATION AND THE MECHANISMS OF NICKEL HYPERACCUMULATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We determined the effect of soil type (organic vs. loam) and liming on Ni speciation in soils surrounding an historic Ni refinery and the influence of this speciation on Ni availability, translocation and storage in the Ni hyperaccumulator Alyssum murale. Using a combination of analytical methods in...

  15. Role of sulfur assimilation pathway in cadmium hyperaccumulation by Sedum alfredii Hance.

    PubMed

    Liang, Jun; Shohag, M J I; Yang, Xiaoe; Tian, Shengke; Zhang, Yibin; Feng, Ying; He, Zhenli

    2014-02-01

    Sedum alfredii Hance is a promising cadmium (Cd) hyperaccumulating plant recently identified in China. However, the physiological and molecular mechanisms underlying Cd accumulation, which differentiate hyperaccumulating ecotype (HE) from non-hyperaccumulating ecotype (NHE) has not been elucidated yet. A hydroponic experiment was conducted to investigate the role of sulfur assimilation pathway in Cd hyperaccumulation by the S. alfredii Hance, by analyzing gene expression pattern in sulfur assimilation pathway and the concentration of some sulfur containing compounds. The results show that, sulfur assimilation pathway was affected by Cd differently in HE and NHE S. alfredii Hance. The gene expression pattern of sulfur assimilation pathway was regulated differently in HE and NHE plants, especially the nicotianamine synthase (NAS). NAS transcript levels in root of HE was 141-fold higher than NHE, while in shoots of HE only 0.31-fold higher than NHE. In HE roots, NAS expression level was maximum 3171-fold higher than shoots, while in NHE plants roots NAS expression level was maximum 45.3-fold higher than shoots. In HE plant roots, sulfur, cysteine and methionine concentrations increased 30%, 46% and 835% respectively, by Cd treatment, but in NHE plants roots, sulfur concentration increased less than 1%, cysteine and methionine concentrations decreased 78.5% and 13.3% respectively, by Cd. Cd exposure increased glutathione levels by 142% in HE but less than 10% in NHE plant roots. PMID:24239266

  16. Elevated nicotianamine levels in Arabidopsis halleri roots play a key role in zinc hyperaccumulation.

    PubMed

    Deinlein, Ulrich; Weber, Michael; Schmidt, Holger; Rensch, Stefan; Trampczynska, Aleksandra; Hansen, Thomas H; Husted, Søren; Schjoerring, Jan K; Talke, Ina N; Krämer, Ute; Clemens, Stephan

    2012-02-01

    Zn deficiency is among the leading health risk factors in developing countries. Breeding of Zn-enriched crops is expected to be facilitated by molecular dissection of plant Zn hyperaccumulation (i.e., the ability of certain plants to accumulate Zn to levels >100-fold higher than normal plants). The model hyperaccumulators Arabidopsis halleri and Noccaea caerulescens share elevated nicotianamine synthase (NAS) expression relative to nonaccumulators among a core of alterations in metal homeostasis. Suppression of Ah-NAS2 by RNA interference (RNAi) resulted in strongly reduced root nicotianamine (NA) accumulation and a concomitant decrease in root-to-shoot translocation of Zn. Speciation analysis by size-exclusion chromatography coupled to inductively coupled plasma mass spectrometry showed that the dominating Zn ligands in roots were NA and thiols. In NAS2-RNAi plants, a marked increase in Zn-thiol species was observed. Wild-type A. halleri plants cultivated on their native soil showed elemental profiles very similar to those found in field samples. Leaf Zn concentrations in NAS2-RNAi lines, however, did not reach the Zn hyperaccumulation threshold. Leaf Cd accumulation was also significantly reduced. These results demonstrate a role for NAS2 in Zn hyperaccumulation also under near-natural conditions. We propose that NA forms complexes with Zn(II) in root cells and facilitates symplastic passage of Zn(II) toward the xylem. PMID:22374395

  17. Elevated Nicotianamine Levels in Arabidopsis halleri Roots Play a Key Role in Zinc Hyperaccumulation[W

    PubMed Central

    Deinlein, Ulrich; Weber, Michael; Schmidt, Holger; Rensch, Stefan; Trampczynska, Aleksandra; Hansen, Thomas H.; Husted, Søren; Schjoerring, Jan K.; Talke, Ina N.; Krämer, Ute; Clemens, Stephan

    2012-01-01

    Zn deficiency is among the leading health risk factors in developing countries. Breeding of Zn-enriched crops is expected to be facilitated by molecular dissection of plant Zn hyperaccumulation (i.e., the ability of certain plants to accumulate Zn to levels >100-fold higher than normal plants). The model hyperaccumulators Arabidopsis halleri and Noccaea caerulescens share elevated nicotianamine synthase (NAS) expression relative to nonaccumulators among a core of alterations in metal homeostasis. Suppression of Ah-NAS2 by RNA interference (RNAi) resulted in strongly reduced root nicotianamine (NA) accumulation and a concomitant decrease in root-to-shoot translocation of Zn. Speciation analysis by size-exclusion chromatography coupled to inductively coupled plasma mass spectrometry showed that the dominating Zn ligands in roots were NA and thiols. In NAS2-RNAi plants, a marked increase in Zn-thiol species was observed. Wild-type A. halleri plants cultivated on their native soil showed elemental profiles very similar to those found in field samples. Leaf Zn concentrations in NAS2-RNAi lines, however, did not reach the Zn hyperaccumulation threshold. Leaf Cd accumulation was also significantly reduced. These results demonstrate a role for NAS2 in Zn hyperaccumulation also under near-natural conditions. We propose that NA forms complexes with Zn(II) in root cells and facilitates symplastic passage of Zn(II) toward the xylem. PMID:22374395

  18. Phytoextraction by arsenic hyperaccumulator Pteris vittata L. from six arsenic-contaminated soils: Repeated harvests

    E-print Network

    Ma, Lena

    Phytoextraction by arsenic hyperaccumulator Pteris vittata L. from six arsenic-contaminated soils: Repeated harvests and arsenic redistribution Maria I.S. Gonzaga a , Jorge A.G. Santos a , Lena Q. Ma b was effective in continuously removing arsenic from contaminated soils after three repeated harvests. Abstract

  19. Is th hyperaccumulating plant Arabidopsis halleri a good candidate for phytoextrac-, G. Sarret2

    E-print Network

    Paris-Sud XI, Université de

    of plants in order to extract, con- tain or immobilize metals in contaminated soil. Some plants calledIs thé hyperaccumulating plant Arabidopsis halleri a good candidate for phytoextrac- tion? S) which are potentially toxic for plants and animais. Phytoextrac- tion could be a solution to treat

  20. The potential of the high-biomass nickel hyperaccumulator Berkheya coddii for phytoremediation and phytomining

    Microsoft Academic Search

    B. H. Robinson; R. R. Brooks; A. W. Howes; J. H. Kirkman; P. E. H. Gregg

    1997-01-01

    Pot trials and tests in outside plots were carried out on the South African Ni hyperaccumulator plant Berkheya coddii in order to establish its potential for phytoremediation of contaminated soils and for phytomining of Ni. Outside trial plots showed that a dry biomass of 22 t\\/ha could be achieved after moderate fertilisation. Pot trials with varying soil amendments with nitrogen

  1. FINAL REPORT. MOLECULAR DISSECTION OF THE CELLULAR MECHANISMS INVOLVED IN NICKEL HYPERACCUMULATION

    EPA Science Inventory

    Hyperaccumulator plant species are able to accumulate between 1-5% of their biomass as metal. However, these plants are often small, slow growing, and do not produce a high biomass. Phytoextraction, a cost-effective, in situ, plant based approach to soil remediation takes advanta...

  2. Effects of heavy metals on growth and arsenic accumulation in the arsenic hyperaccumulator Pteris vittata L.

    E-print Network

    Ma, Lena

    metals. Published by Elsevier Ltd. Keywords: Phytoremediation; Heavy metals; Arsenic uptake; Speciation (EPA, 2001). Phytoremediation, the use of plants for environmental restoration, has been proposed of phytoremediation (Reeves and Baker, 2000). Hyperaccumulators are plants and/or genotypes that accumulate metals

  3. PROGRESS REPORT. MOLECULAR DISSECTION OF THE CELLULAR MECHANISMS INVOLVED IN NICKEL HYPERACCUMULATION

    EPA Science Inventory

    Hyperaccumulator plant species are able to accumulate between 1-5% of their biomass as metal. However, these plants are often small, slow growing, and do not produce a high biomass. Phytoextraction, a cost-effective, in situ, plant based approach to soil remediation takes advanta...

  4. The nickel hyperaccumulator plant Alyssum bertolonii as a potential agent for phytoremediation and phytomining of nickel

    Microsoft Academic Search

    B. H. Robinson; A. Chiarucci; R. R. Brooks; D. Petit; J. H. Kirkman; P. E. H. Gregg; V. De Dominicis

    1997-01-01

    Experiments were carried out in Italy on the potential use of the hyperaccumulator Alyssum bertolonii in phytomining of ultramafic soils for Ni. In situ experimental plots at Murlo, Tuscany were fertilized with various regimes during a 2-year period. The best fertilizer treatment (N + K + P) gave a threefold increase of the biomass of reproductive matter to 9.0 t\\/ha

  5. High-throughput fluorescence-activated cell sorting for lipid hyperaccumulating Chlamydomonas reinhardtii mutants.

    PubMed

    Xie, Bo; Stessman, Dan; Hart, Jason H; Dong, Haili; Wang, Yingjun; Wright, David A; Nikolau, Basil J; Spalding, Martin H; Halverson, Larry J

    2014-09-01

    The genetically tractable microalga Chlamydomonas reinhardtii has many advantages as a model for renewable bioproducts and/or biofuels production. However, one limitation of C. reinhardtii is its relatively low-lipid content compared with some other algal species. To overcome this limitation, we combined ethane methyl sulfonate mutagenesis with fluorescence-activated cell sorting (FACS) of cells stained with the lipophilic stain Nile Red to isolate lipid hyperaccumulating mutants of C. reinhardtii. By manipulating the FACS gates, we sorted mutagenized cells with extremely high Nile Red fluorescence signals that were rarely detected in nonmutagenized populations. This strategy successfully isolated several putative lipid hyperaccumulating mutants exhibiting 23% to 58% (dry weight basis) higher fatty acid contents than their progenitor strains. Significantly, for most mutants, nitrogen starvation was not required to attain high-lipid content nor was there a requirement for a deficiency in starch accumulation. Microscopy of Nile Red stained cells revealed that some mutants exhibit an increase in the number of lipid bodies, which correlated with TLC analysis of triacyglycerol content. Increased lipid content could also arise through increased biomass production. Collectively, our findings highlight the ability to enhance intracellular lipid accumulation in algae using random mutagenesis in conjunction with a robust FACS and lipid yield verification regime. Our lipid hyperaccumulating mutants could serve as a genetic resource for stacking additional desirable traits to further increase lipid production and for identifying genes contributing to lipid hyperaccumulation, without lengthy lipid-induction periods. PMID:24702864

  6. Hyperaccumulator Alyssum Murale Relies on a Different Metal Storage Mechanism for Cobalt than for Nickel.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nickel hyperaccumulator Alyssum murale has been developed as a commercial crop for phytoremediation/phytomining Ni-enriched soils (anthropogenic/geogenic) containing elevated concentrations of other metals. Metal co-tolerance, accumulation, and localization were investigated for Alyssum exposed to c...

  7. Selenium hyperaccumulation offers protection from cell disruptor herbivores Colin F. Quinn1,#

    E-print Network

    . In this study we investigate the protective function of Se in the Se hyperaccumulators Stanleya pinnata. pinnata with high Se concentrations (greater than 650 mg Se kg-1 ) were less subject to thrips herbivory. Spider mites also preferred to feed on low-Se A. bisulcatus and S. pinnata plants rather than high

  8. Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata1[W][OA

    E-print Network

    Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata1[W][OA] John L- accumulator Stanleya pinnata (Brassicaceae) by comparing it with the related secondary Se accumulator Stanleya albescens using a combination of physiological, structural, genomic, and biochemical approaches. S. pinnata

  9. Spatial Imaging, Speciation, and Quantification of Selenium in the Hyperaccumulator Plants Astragalus

    E-print Network

    Astragalus bisulcatus and Stanleya pinnata1 John L. Freeman, Li Hong Zhang, Matthew A. Marcus, Sirine Fakra, Rothamsted Research, Harpenden, Herts AL5 2JQ, United Kingdom (S.P.M.) Astragalus bisulcatus and Stanleya pinnata hyperaccumulate selenium (Se) up to 1% of plant dry weight. In the field, Se was mostly present

  10. Interactions of selenium hyperaccumulators and nonaccumulators during cocultivation on seleniferous or

    E-print Network

    bisulcatus and Stanleya pinnata and nonaccumulators Astragalus drummondii and Stanleya elata were, hyperaccumulation, phytoenrichment, plant­plant interactions, selenium, Stanleya. Summary · This study investigated accumulated relatively more C-Se-C and less selenate when growing adjacent to S. pinnata. Both

  11. THE PLANT SOIL INTERFACE: NICKEL BIOAVAILABILITY AND THE MECHANISMS OF PLANT HYPERACCUMULATION

    E-print Network

    Sparks, Donald L.

    fulfillment of the requirements for the degree of Doctor of Philosophy in Plant and Soil Sciences Winter 2006THE PLANT SOIL INTERFACE: NICKEL BIOAVAILABILITY AND THE MECHANISMS OF PLANT HYPERACCUMULATION and Learning Company. #12;ii THE PLANT SOIL INTERFACE: NICKEL BIOAVAILABILITY AND THE MECHANISMS OF PLANT

  12. Spatial imaging, speciation, and quantification of selenium in the hyperaccumulator plants Astragalus bisulcatus and Stanleya pinnata.

    PubMed

    Freeman, John L; Zhang, Li Hong; Marcus, Matthew A; Fakra, Sirine; McGrath, Steve P; Pilon-Smits, Elizabeth A H

    2006-09-01

    Astragalus bisulcatus and Stanleya pinnata hyperaccumulate selenium (Se) up to 1% of plant dry weight. In the field, Se was mostly present in the young leaves and reproductive tissues of both hyperaccumulators. Microfocused scanning x-ray fluorescence mapping revealed that Se was hyperaccumulated in trichomes in young leaves of A. bisulcatus. None of 10 other elements tested were accumulated in trichomes. Micro x-ray absorption spectroscopy and liquid chromatography-mass spectrometry showed that Se in trichomes was present in the organic forms methylselenocysteine (MeSeCys; 53%) and gamma-glutamyl-MeSeCys (47%). In the young leaf itself, there was 30% inorganic Se (selenate and selenite) in addition to 70% MeSeCys. In young S. pinnata leaves, Se was highly concentrated near the leaf edge and surface in globular structures that were shown by energy-dispersive x-ray microanalysis to be mainly in epidermal cells. Liquid chromatography-mass spectrometry revealed both MeSeCys (88%) and selenocystathionine (12%) inside leaf edges. In contrast, both the Se accumulator Brassica juncea and the nonaccumulator Arabidopsis thaliana accumulated Se in their leaf vascular tissues and mesophyll cells. Se in hyperaccumulators appears to be mobile in both the xylem and phloem because Se-treated S. pinnata was found to be highly toxic to phloem-feeding aphids, and MeSeCys was present in the vascular tissues of a S. pinnata young leaf petiole as well as in guttation fluid. The compartmentation of organic selenocompounds in specific storage areas in the plant periphery appears to be a unique property of Se hyperaccumulators. The high concentration of Se in the plant periphery may contribute to Se tolerance and may also serve as an elemental plant defense mechanism. PMID:16920881

  13. SPECTROMICROSCOPIC INVESTIGATION OF CO SPECIATION IN A NI/CO HYPERACCUMULATOR PLANT USED FOR PHYTOREMEDIATION AND PHYTOMINING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metal contamination of surface and subsurface environments is a worldwide concern. Unique metallophyte plants (hyperaccumulators) accumulate high concentrations of trace metals in their harvestable biomass, and thereby offer a sustainable method for treatment of metal-contaminated sites (phytoremed...

  14. The role of selenium in protecting plants against prairie dog herbivory: implications for the evolution of selenium hyperaccumulation

    Microsoft Academic Search

    Colin F. Quinn; John L. Freeman; Miriam L. Galeas; Erin M. Klamper; Elizabeth A. H. Pilon-Smits

    2008-01-01

    Some plants can hyperaccumulate the element selenium (Se) up to 10,000 mg Se kg?1 dry weight. Hyperaccumulation has been hypothesized to defend against herbivory. In laboratory studies high Se levels protect\\u000a plants from invertebrate herbivores and pathogens. However, field studies and mammalian herbivore studies that link Se accumulation\\u000a to herbivory protection are lacking. In this study a combination of field surveys

  15. [Hyperaccumulative characteristics of 7 widely distributing weed species in composite family especially Bidens pilosa to heavy metals].

    PubMed

    Wei, Shu-He; Yang, Chuan-Jie; Zhou, Qi-Xing

    2008-10-01

    Hyperaccumulator is the main point of phytoremediating contaminated soils by heavy metals, and the identification of hyperaccumulator is still the difficult and key step of phytoremediation. The outdoor pot-culture experiment was used to study the hyperaccumulative characteristics of 7 widely distributing weed species in Northeast of China to heavy metals. The results in screening experiment showed that Taraxacum mongolicum and Bidens pilosa indicated strong tolerance to Cd single and Cd-Pb-Cu-Zn combined pollution, their Cd concentration in shoot were higher than that in roots, and the Cd enhancement factors (ratio of heavy metal concentration in shoot to that in soil) in shoots were greater than 1 too, which displayed that the two plants were with Cd hyperaccumulative characteristics. In concentration gradient experiment, Cd concentration in leaves of B. pilosa were all greater than 100 mg x kg(-1) the minimum of Cd-hyperaccumulator should have under the conditions of 25, 50, 100 mg x kg(-1) Cd added. Meanwhile, the shoot biomass of B. pilosa did not reduce significantly (p <0.05), Cd concentration in its shoots were higher than those in roots. But for T. mongolicum, Cd concentration in its shoots were not greater than 100 mg x kg(-1) in any treatment. Thus, only B. pilosa can be regarded as Cd-hyperaccumulator. PMID:19143394

  16. Hyperaccumulation of lead, zinc, and cadmium in plants growing on a lead/zinc outcrop in Yunnan Province, China

    NASA Astrophysics Data System (ADS)

    Wang, S. L.; Liao, W. B.; Yu, F. Q.; Liao, B.; Shu, W. S.

    2009-08-01

    A field survey was conducted to identify potential hyperaccumulators of Pb, Zn or Cd in the Beichang Pb/Zn mine outcrop in Yunnan Province, China. The average total concentrations of Pb, Zn, and Cd in the soils were up to 28,438, 5,109, and 52 mg kg-1, respectively. A total of 68 plant species belonging to 60 genera of 37 families naturally colonizing the outcrop were recorded. According to metal accumulation in the plants and translocation factor (TF), Silene viscidula was identified as potential hyperaccumulator of Pb, Zn, and Cd with mean shoot concentrations of 3,938 mg kg-1 of Pb (TF = 1.2), 11,155 mg kg-1 of Zn (TF = 1.8) and 236 mg kg-1 of Cd (TF = 1.1), respectively; S. gracilicanlis (Pb 3,617 mg kg-1, TF = 1.2) and Onosma paniculatum (Pb 1,837 mg kg-1, TF = 1.9) were potential Pb hyperaccumulators. Potentilla griffithii (Zn 8,748 mg kg-1, TF = 1.5) and Gentiana sp. (Zn 19,710 mg kg-1, TF = 2.7) were potential Zn hyperaccumulators. Lysimachia deltoides (Cd 212 mg kg-1, TF = 3.2) was a potential Cd hyperaccumulator. These new plant resources could be used to explore the mechanisms of Pb, Zn and/or Cd hyperaccumulation, and the findings could be applied for the phytoremediation of Pb, Zn and/or Cd-contaminated soils.

  17. Interactions of selenium hyperaccumulators and nonaccumulators during cocultivation on seleniferous or nonseleniferous soil--the importance of having good neighbors.

    PubMed

    Mehdawi, Ali F El; Cappa, Jennifer J; Fakra, Sirine C; Self, James; Pilon-Smits, Elizabeth A H

    2012-04-01

    • This study investigated how selenium (Se) affects relationships between Se hyperaccumulator and nonaccumulator species, particularly how plants influence their neighbors' Se accumulation and growth. • Hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and nonaccumulators Astragalus?drummondii and Stanleya?elata were cocultivated on seleniferous or nonseleniferous soil, or on gravel supplied with different selenate concentrations. The plants were analyzed for growth, Se accumulation and Se speciation. Also, root exudates were analyzed for Se concentration. • The hyperaccumulators showed 2.5-fold better growth on seleniferous than on nonseleniferous soil, and up to fourfold better growth with increasing Se supply; the nonaccumulators showed the opposite results. Both hyperaccumulators and nonaccumulators could affect growth (up to threefold) and Se accumulation (up to sixfold) of neighboring plants. Nonaccumulators S. elata and A. drummondii accumulated predominantly (88-95%) organic C-Se-C; the remainder was selenate. S. elata accumulated relatively more C-Se-C and less selenate when growing adjacent to S. pinnata. Both hyperaccumulators released selenocompounds from their roots. A. bisulcatus exudate contained predominantly C-Se-C compounds; no speciation data could be obtained for S. pinnata. • Thus, plants can affect Se accumulation in neighbors, and soil Se affects competition and facilitation between plants. This helps to explain why hyperaccumulators are found predominantly on seleniferous soils. PMID:22269105

  18. Heavy metal concentrations in plants growing on a copper mine spoil in the Grand Canyon, Arizona. [Thlaspi montanum; Phlox austromontana; Juniperus osteosperma

    SciTech Connect

    Hobbs, R.J.; Streit, B.

    1986-05-01

    Concentrations of metals including manganese, nickel, copper and zinc were measured in soil from a copper mine spoil heap in the Grand Canyon, Arizona, and in three plant species growing on the spoil. The soil had high concentrations of available copper and zinc, and the herbaceous perennial Thlaspi montanum var fendleri contained amounts of Ni, Cu and Zn in direct proportion to the soil concentrations (EDTA extractable). Another herbaceous perennial, Phlox austromontana, and the woody perennial Juniperus osteosperma had considerably lower amounts of these elements. These findings are discussed in relation to other studies, and it is suggested that figures for metal accumulation by plants should always be related to plant-available soil concentrations.

  19. Rinorea niccolifera (Violaceae), a new, nickel-hyperaccumulating species from Luzon Island, Philippines

    PubMed Central

    Fernando, Edwino S.; Quimado, Marilyn O.; Doronila, Augustine I.

    2014-01-01

    Abstract A new, nickel-hyperaccumulating species of Rinorea (Violaceae), Rinorea niccolifera Fernando, from Luzon Island, Philippines, is described and illustrated. This species is most similar to the widespread Rinorea bengalensis by its fasciculate inflorescences and smooth subglobose fruits with 3 seeds, but it differs by its glabrous ovary with shorter style (5 mm long), the summit of the staminal tube sinuate to entire and the outer surface smooth, generally smaller leaves (3–8 cm long × 2–3 cm wide), and smaller fruits (0.6–0.8 cm diameter). Rinorea niccolifera accumulates to >18,000 µg g-1 of nickel in its leaf tissues and is thus regarded as a Ni hyperaccumulator. PMID:24843295

  20. Isolation and Characterization of Endophytic Bacteria from the Nickel Hyperaccumulator Plant Alyssum bertolonii

    Microsoft Academic Search

    Rita Barzanti; Francesca Ozino; Marco Bazzicalupo; Roberto Gabbrielli; Francesca Galardi; Cristina Gonnelli; Alessio Mengoni

    2007-01-01

    We report the isolation and characterization of endophytic bacteria, endemic to serpentine outcrops of Central Italy, from\\u000a a nickel hyperaccumulator plant, Alyssum bertolonii Desv. (Brassicaceae). Eighty-three endophytic bacteria were isolated from roots, stems, and leaves of A. bertolonii and classified by restriction analysis of 16S rDNA (ARDRA) and partial 16S rDNA sequencing in 23 different taxonomic groups.\\u000a All isolates were

  1. Cellular compartmentation of cadmium and zinc in relation to other elements in the hyperaccumulator Arabidopsis halleri

    Microsoft Academic Search

    Hendrik Küpper; Enzo Lombi; Fang-Jie Zhao; Steve P. McGrath

    2000-01-01

    .   The cellular compartmentation of elements was analysed in the Zn hyperaccumulator Arabidopsis halleri (L.) O'Kane & Al-Shehbaz (=Cardaminopsis halleri) using energy-dispersive X-ray microanalysis of frozen-hydrated tissues. Quantitative data were obtained using oxygen as\\u000a an internal standard in the analyses of vacuoles, whereas a peak\\/background ratio method was used for quantification of elements\\u000a in pollen and dehydrated trichomes. Arabidopsis halleri

  2. Phytoremediation of Arsenic-Contaminated Groundwater by the Arsenic Hyperaccumulating Fern Pteris vittata L

    Microsoft Academic Search

    S. Tu; Lena Q. Ma; Abioye O. Fayiga; Edward J. Zillioux

    2004-01-01

    Arsenic concentrations in a much larger fraction of U.S. groundwater sources will exceed the maximum contaminant limit when the new 10 ?g L EPA standard for drinking water takes effect in 2006. Thus, it is important to develop remediation technologies that can meet this new standard. Phytoremediation of arsenic-contaminated groundwater is a relatively new idea. In this research, an arsenic-hyperaccumulating

  3. Developing an Agrobacterium tumefaciens -mediated genetic transformation for a selenium-hyperaccumulator Astragalus racemosus

    Microsoft Academic Search

    Diane E. Darlington; Chiu-Yueh Hung; Jiahua Xie

    2009-01-01

    Agrobacterium\\u000a tumefaciens strain LBA4404 containing the plasmid pBI121, carrying the reporter gene uidA and the kanamycin resistance gene nptII, was used for gene transfer experiments in selenium (Se)-hyperaccumulator Astragalus racemosus. The effects of kanamycin on cell growth and division and acetosyringone on transformation efficiency were evaluated. The\\u000a optimal concentration of kanamycin that could effectively inhibit cell growth and division in

  4. Selenium Distribution and Speciation in the Hyperaccumulator Astragalus bisulcatus and Associated Ecological Partners1[W][OA

    PubMed Central

    Valdez Barillas, José R.; Quinn, Colin F.; Freeman, John L.; Lindblom, Stormy D.; Fakra, Sirine C.; Marcus, Matthew A.; Gilligan, Todd M.; Alford, Élan R.; Wangeline, Ami L.; Pilon-Smits, Elizabeth A.H.

    2012-01-01

    The goal of this study was to investigate how plant selenium (Se) hyperaccumulation may affect ecological interactions and whether associated partners may affect Se hyperaccumulation. The Se hyperaccumulator Astragalus bisulcatus was collected in its natural seleniferous habitat, and x-ray fluorescence mapping and x-ray absorption near-edge structure spectroscopy were used to characterize Se distribution and speciation in all organs as well as in encountered microbial symbionts and herbivores. Se was present at high levels (704–4,661 mg kg?1 dry weight) in all organs, mainly as organic C-Se-C compounds (i.e. Se bonded to two carbon atoms, e.g. methylselenocysteine). In nodule, root, and stem, up to 34% of Se was found as elemental Se, which was potentially due to microbial activity. In addition to a nitrogen-fixing symbiont, the plants harbored an endophytic fungus that produced elemental Se. Furthermore, two Se-resistant herbivorous moths were discovered on A. bisulcatus, one of which was parasitized by a wasp. Adult moths, larvae, and wasps all accumulated predominantly C-Se-C compounds. In conclusion, hyperaccumulators live in association with a variety of Se-resistant ecological partners. Among these partners, microbial endosymbionts may affect Se speciation in hyperaccumulators. Hyperaccumulators have been shown earlier to negatively affect Se-sensitive ecological partners while apparently offering a niche for Se-resistant partners. Through their positive and negative effects on different ecological partners, hyperaccumulators may influence species composition and Se cycling in seleniferous ecosystems. PMID:22645068

  5. A more complete picture of metal hyperaccumulation through next-generation sequencing technologies.

    PubMed

    Verbruggen, Nathalie; Hanikenne, Marc; Clemens, Stephan

    2013-01-01

    The mechanistic understanding of metal hyperaccumulation has benefitted immensely from the use of molecular genetics tools developed for Arabidopsis thaliana. The revolution in DNA sequencing will enable even greater strides in the near future, this time not restricted to the family Brassicaceae. Reference genomes are within reach for many ecologically interesting species including heterozygous outbreeders. They will allow deep RNA-seq transcriptome studies and the re-sequencing of contrasting individuals to unravel the genetic basis of phenotypic variation. Cell-type specific transcriptome analyses, which will be essential for the dissection of metal translocation pathways in hyperaccumulators, can be achieved through the combination of RNA-seq and translatome approaches. Affordable high-resolution genotyping of many individuals enables the elucidation of quantitative trait loci in intra- and interspecific crosses as well as through genome-wide association mapping across large panels of accessions. Furthermore, genome-wide scans have the power to detect loci under recent selection. Together these approaches will lead to a detailed understanding of the evolutionary path towards the emergence of hyperaccumulation traits. PMID:24098304

  6. Mn accumulation and tolerance in Celosia argentea Linn.: a new Mn-hyperaccumulating plant species.

    PubMed

    Liu, Jie; Shang, Weiwei; Zhang, Xuehong; Zhu, Yinian; Yu, Ke

    2014-02-28

    Identifying a hyperaccumulator is an important groundwork for the phytoextraction of heavy metal-contaminated soil. Celosia argentea Linn., which grew on a Mn tailing wasteland, was found to hyperaccumulate Mn (14 362mgkg(-1) in leaf dry matter) in this study. To investigate Mn tolerance and accumulation in C. argentea, a hydroponic culture experiment was conducted in a greenhouse. Results showed that the biomass and the relative growth rate of C. argentea were insignificantly different (p>0.05) at the Mn supply level ranging from 2.5mgL(-1) (control) to 400mgL(-1). Manganese concentrations in leaves, stems, and roots reached maxima of 20228, 8872, and 2823mgkg(-1) at 600mgMnL(-1), respectively. The relative rate of Mn accumulation increased by 91.2% at 400mgMnL(-1). Over 95% of the total Mn taken up by C. argentea was translocated to shoots. Thus, C. argentea exhibits the basic characteristics of a Mn-hyperaccumulator. This species has great potential to remediate Mn-contaminated soil cheaply and can also aid the studies of Mn uptake, translocation, speciation, distribution and detoxification in plants. PMID:24444455

  7. A more complete picture of metal hyperaccumulation through next-generation sequencing technologies

    PubMed Central

    Verbruggen, Nathalie; Hanikenne, Marc; Clemens, Stephan

    2013-01-01

    The mechanistic understanding of metal hyperaccumulation has benefitted immensely from the use of molecular genetics tools developed for Arabidopsis thaliana. The revolution in DNA sequencing will enable even greater strides in the near future, this time not restricted to the family Brassicaceae. Reference genomes are within reach for many ecologically interesting species including heterozygous outbreeders. They will allow deep RNA-seq transcriptome studies and the re-sequencing of contrasting individuals to unravel the genetic basis of phenotypic variation. Cell-type specific transcriptome analyses, which will be essential for the dissection of metal translocation pathways in hyperaccumulators, can be achieved through the combination of RNA-seq and translatome approaches. Affordable high-resolution genotyping of many individuals enables the elucidation of quantitative trait loci in intra- and interspecific crosses as well as through genome-wide association mapping across large panels of accessions. Furthermore, genome-wide scans have the power to detect loci under recent selection. Together these approaches will lead to a detailed understanding of the evolutionary path towards the emergence of hyperaccumulation traits. PMID:24098304

  8. Hyperaccumulator Alyssum murale Relies on a Different Metal Storage Mechanism for Cobalt than for Nickel

    SciTech Connect

    Tappero, R.; Peltier, E; Grafe, M; Heidel, K; Ginder-Vogel, M; Livi, K; Rivers, M; Marcus, M; Chaney, R; Sparks, D

    2007-01-01

    The nickel (Ni) hyperaccumulator Alyssum murale has been developed as a commercial crop for phytoremediation/phytomining Ni from metal-enriched soils. Here, metal co-tolerance, accumulation and localization were investigated for A. murale exposed to metal co-contaminants. A. murale was irrigated with Ni-enriched nutrient solutions containing basal or elevated concentrations of cobalt (Co) or zinc (Zn). Metal localization and elemental associations were investigated in situ with synchrotron X-ray microfluorescence (SXRF) and computed-microtomography (CMT). A. murale hyperaccumulated Ni and Co (> 1000 {micro}g g{sup -1} dry weight) from mixed-metal systems. Zinc was not hyperaccumulated. Elevated Co or Zn concentrations did not alter Ni accumulation or localization. SXRF images showed uniform Ni distribution in leaves and preferential localization of Co near leaf tips/margins. CMT images revealed that leaf epidermal tissue was enriched with Ni but devoid of Co, that Co was localized in the apoplasm of leaf ground tissue and that Co was sequestered on leaf surfaces near the tips/margins. Cobalt-rich mineral precipitate(s) form on leaves of Co-treated A. murale. Specialized biochemical processes linked with Ni (hyper)tolerance in A. murale do not confer (hyper)tolerance to Co. A. murale relies on a different metal storage mechanism for Co (exocellular sequestration) than for Ni (vacuolar sequestration).

  9. Fractionation of stable zinc isotopes in the zinc hyperaccumulator Arabidopsis halleri and nonaccumulator Arabidopsis petraea.

    PubMed

    Aucour, A M; Pichat, S; Macnair, M R; Oger, P

    2011-11-01

    Zn isotope fractionation may provide new insights into Zn uptake, transport and storage mechanisms in plants. It was investigated here in the Zn hyperaccumulator Arabidopsis halleri and the nonaccumulator A. petraea. Plant growth on hydroponic solution allowed us to measure the isotope fractionation between source Zn (with Zn(2+) as dominant form), shoot and root. Zn isotope mass balance yields mean isotope fractionation between plant and source Zn ?(66)Zn(in-source) of -0.19 ± 0.20‰ in the nonaccumulator and of -0.05 ± 0.12‰ in the hyperaccumulator. The isotope fractionation between shoot Zn and bulk Zn incorporated (?(66)Zn(shoot-in)) differs between the nonaccumulator and the hyperaccumulator and is function of root-shoot translocation (as given by mass ratio between shoot Zn and bulk plant Zn). The large isotope fractionation associated with sequestration in the root (0.37‰) points to the binding of Zn(2+) with a high affinity ligand in the root cell. We conclude that Zn stable isotopes may help to estimate underground and aerial Zn storage in plants and be useful in studying extracellular and cellular mechanisms of sequestration in the root. PMID:21882835

  10. A Ni hyperaccumulator and a congeneric non-accumulator reveal equally effective defenses against herbivory.

    PubMed

    Vilas Boas, Liliana; Gonçalves, Susana C; Portugal, António; Freitas, Helena; Gonçalves, M Teresa

    2014-01-01

    The defense hypothesis is commonly used to explain the adaptive role of metal hyperaccumulation. We tested this hypothesis using two Brassicaceae congeneric species: Alyssum pintodasilvae, a Ni hyperaccumulator, and the non-accumulator Alyssum simplex both growing on serpentine soils in Portugal. Artificial diet disks amended with powdered leaves from each plant species were used to compare the performance (mortality, biomass change) and feeding behavior of Tribolium castaneum in no-choice and choice tests. The performance of T. castaneum was not affected at several concentrations of A. pintodasilvae or A. simplex in no-choice tests. However, the consumption of plant-amended disks was significantly lower than that of control disks, irrespectively of the species fed. Accordingly, when insects were given an alternative food choice, disks of both plant species were significantly less consumed than control disks. Moreover, insects did not discriminate between disks in the combination "A. pintodasilvae+A. simplex". Contrary to our expectations, these results suggest that both plant species have equally effective defenses against herbivory. While Ni is believed to be part of the deterrence mechanism in the hyperaccumulator A. pintodasilvae, it seems likely that organic compounds, possibly glucosinolates, play an important role in the defense of A. simplex or in both species. PMID:23892018

  11. The potential of phytoremediation using hyperaccumulator plants: a case study at a lead-zinc mine site.

    PubMed

    Lorestani, Bahareh; Cheraghi, Mehrdad; Yousefi, Nafiseh

    2012-09-01

    Contamination with heavy metals is one of the most pressing threats to water and soil resources, as well as human health. Phytoremediation might potentially be used to remediate metal-contaminated sites. A major advance in the development of phytoremediation for heavy metal affected soils was the discovery of heavy metal hyperaccumulation in plants. This study applied several established criteria to identify hyperaccumulator plants. A case study was conducted at a mining area in the Hamedan province in the west central region of Iran. The results indicated that plant metal accumulation differed among species and plant parts. Plant species grown in substrata with elevated metal levels contained significantly higher metal levels. Using the most common criteria, Euphorbia macroclada and Centaurea virgata can be classified as hyperaccumulators of specific heavy metals measured in this study and they might potentially be used for the phytoremediation of contaminated soils. PMID:22908644

  12. Selenium hyperaccumulators harbor a diverse endophytic bacterial community characterized by high selenium resistance and plant growth promoting properties.

    PubMed

    Sura-de Jong, Martina; Reynolds, Ray J B; Richterova, Klara; Musilova, Lucie; Staicu, Lucian C; Chocholata, Iva; Cappa, Jennifer J; Taghavi, Safiyh; van der Lelie, Daniel; Frantik, Tomas; Dolinova, Iva; Strejcek, Michal; Cochran, Alyssa T; Lovecka, Petra; Pilon-Smits, Elizabeth A H

    2015-01-01

    Selenium (Se)-rich plants may be used to provide dietary Se to humans and livestock, and also to clean up Se-polluted soils or waters. This study focused on endophytic bacteria of plants that hyperaccumulate selenium (Se) to 0.5-1% of dry weight. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to compare the diversity of endophytic bacteria of hyperaccumulators Stanleya pinnata (Brassicaceae) and Astragalus bisulcatus (Fabaceae) with those from related non-accumulators Physaria bellii (Brassicaceae) and Medicago sativa (Fabaceae) collected on the same, seleniferous site. Hyperaccumulators and non-accumulators showed equal T-RF diversity. Parsimony analysis showed that T-RFs from individuals of the same species were more similar to each other than to those from other species, regardless of plant Se content or spatial proximity. Cultivable endophytes from hyperaccumulators S. pinnata and A. bisulcatus were further identified and characterized. The 66 bacterial morphotypes were shown by MS MALDI-TOF Biotyper analysis and 16S rRNA gene sequencing to include strains of Bacillus, Pseudomonas, Pantoea, Staphylococcus, Paenibacillus, Advenella, Arthrobacter, and Variovorax. Most isolates were highly resistant to selenate and selenite (up to 200 mM) and all could reduce selenite to red elemental Se, reduce nitrite and produce siderophores. Seven isolates were selected for plant inoculation and found to have plant growth promoting properties, both in pure culture and when co-cultivated with crop species Brassica juncea (Brassicaceae) or M. sativa. There were no effects on plant Se accumulation. We conclude that Se hyperaccumulators harbor an endophytic bacterial community in their natural seleniferous habitat that is equally diverse to that of comparable non-accumulators. The hyperaccumulator endophytes are characterized by high Se resistance, capacity to produce elemental Se and plant growth promoting properties. PMID:25784919

  13. Selenium hyperaccumulators harbor a diverse endophytic bacterial community characterized by high selenium resistance and plant growth promoting properties

    PubMed Central

    Sura-de Jong, Martina; Reynolds, Ray J. B.; Richterova, Klara; Musilova, Lucie; Staicu, Lucian C.; Chocholata, Iva; Cappa, Jennifer J.; Taghavi, Safiyh; van der Lelie, Daniel; Frantik, Tomas; Dolinova, Iva; Strejcek, Michal; Cochran, Alyssa T.; Lovecka, Petra; Pilon-Smits, Elizabeth A. H.

    2015-01-01

    Selenium (Se)-rich plants may be used to provide dietary Se to humans and livestock, and also to clean up Se-polluted soils or waters. This study focused on endophytic bacteria of plants that hyperaccumulate selenium (Se) to 0.5–1% of dry weight. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to compare the diversity of endophytic bacteria of hyperaccumulators Stanleya pinnata (Brassicaceae) and Astragalus bisulcatus (Fabaceae) with those from related non-accumulators Physaria bellii (Brassicaceae) and Medicago sativa (Fabaceae) collected on the same, seleniferous site. Hyperaccumulators and non-accumulators showed equal T-RF diversity. Parsimony analysis showed that T-RFs from individuals of the same species were more similar to each other than to those from other species, regardless of plant Se content or spatial proximity. Cultivable endophytes from hyperaccumulators S. pinnata and A. bisulcatus were further identified and characterized. The 66 bacterial morphotypes were shown by MS MALDI-TOF Biotyper analysis and 16S rRNA gene sequencing to include strains of Bacillus, Pseudomonas, Pantoea, Staphylococcus, Paenibacillus, Advenella, Arthrobacter, and Variovorax. Most isolates were highly resistant to selenate and selenite (up to 200 mM) and all could reduce selenite to red elemental Se, reduce nitrite and produce siderophores. Seven isolates were selected for plant inoculation and found to have plant growth promoting properties, both in pure culture and when co-cultivated with crop species Brassica juncea (Brassicaceae) or M. sativa. There were no effects on plant Se accumulation. We conclude that Se hyperaccumulators harbor an endophytic bacterial community in their natural seleniferous habitat that is equally diverse to that of comparable non-accumulators. The hyperaccumulator endophytes are characterized by high Se resistance, capacity to produce elemental Se and plant growth promoting properties. PMID:25784919

  14. A comparative analysis of endophytic bacterial communities associated with hyperaccumulators growing in mine soils.

    PubMed

    Chen, Liang; Luo, Shenglian; Chen, Jueliang; Wan, Yong; Li, Xiaojie; Liu, Chengbin; Liu, Feng

    2014-06-01

    Interactions between endophytic bacterial communities and hyperaccumulators in heavy metal-polluted sites are not fully understood. In this study, the diversity of stem-associated endophytic bacterial communities of two hyperaccumulators (Solanum nigrum L. and Phytolacca acinosa Roxb.) growing in mine soils was investigated using molecular-based methods. The denaturing gradient gel electrophoresis (DGGE) analysis showed that the endophytic bacterial community structures were affected by both the level of heavy metal pollution and the plant species. Heavy metal in contaminated soil determined, to a large extent, the composition of the different endophytic bacterial communities in S. nigrum growing across soil series (five sampling spots, and the concentration of Cd is from 0.2 to 35.5 mg/kg). Detailed analysis of endophytic bacterial populations by cloning of 16S rRNA genes amplified from the stems of the two plants at the same site revealed a different composition. A total of 51 taxa at the genus level that included ?-, ?-, and ?-Proteobacteria (68.8% of the two libraries clones), Bacteroidetes (9.0% of the two libraries clones), Firmicutes (2.0% of the two libraries clones), Actinobacteria (16.4% of the two libraries clones), and unclassified bacteria (3.8% of the two libraries clones) were found in the two clone libraries. The most abundant genus in S. nigrum was Sphingomonas (23.35%), while Pseudomonas prevailed in P. acinosa (21.40%). These results suggest that both heavy metal pollution and plant species contribute to the shaping of the dynamic endophytic bacterial communities associated with stems of hyperaccumulators. PMID:24595752

  15. Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata1[W][OA

    PubMed Central

    Freeman, John L.; Tamaoki, Masanori; Stushnoff, Cecil; Quinn, Colin F.; Cappa, Jennifer J.; Devonshire, Jean; Fakra, Sirine C.; Marcus, Matthew A.; McGrath, Steve P.; Van Hoewyk, Doug; Pilon-Smits, Elizabeth A.H.

    2010-01-01

    The molecular mechanisms responsible for selenium (Se) tolerance and hyperaccumulation were studied in the Se hyperaccumulator Stanleya pinnata (Brassicaceae) by comparing it with the related secondary Se accumulator Stanleya albescens using a combination of physiological, structural, genomic, and biochemical approaches. S. pinnata accumulated 3.6-fold more Se and was tolerant to 20 ?m selenate, while S. albescens suffered reduced growth, chlorosis and necrosis, impaired photosynthesis, and high levels of reactive oxygen species. Levels of ascorbic acid, glutathione, total sulfur, and nonprotein thiols were higher in S. pinnata, suggesting that Se tolerance may in part be due to increased antioxidants and up-regulated sulfur assimilation. S. pinnata had higher selenocysteine methyltransferase protein levels and, judged from liquid chromatography-mass spectrometry, mainly accumulated the free amino acid methylselenocysteine, while S. albescens accumulated mainly the free amino acid selenocystathionine. S. albescens leaf x-ray absorption near-edge structure scans mainly detected a carbon-Se-carbon compound (presumably selenocystathionine) in addition to some selenocysteine and selenate. Thus, S. albescens may accumulate more toxic forms of Se in its leaves than S. pinnata. The species also showed different leaf Se sequestration patterns: while S. albescens showed a diffuse pattern, S. pinnata sequestered Se in localized epidermal cell clusters along leaf margins and tips, concentrated inside of epidermal cells. Transcript analyses of S. pinnata showed a constitutively higher expression of genes involved in sulfur assimilation, antioxidant activities, defense, and response to (methyl)jasmonic acid, salicylic acid, or ethylene. The levels of some of these hormones were constitutively elevated in S. pinnata compared with S. albescens, and leaf Se accumulation was slightly enhanced in both species when these hormones were supplied. Thus, defense-related phytohormones may play an important signaling role in the Se hyperaccumulation of S. pinnata, perhaps by constitutively up-regulating sulfur/Se assimilation followed by methylation of selenocysteine and the targeted sequestration of methylselenocysteine. PMID:20498337

  16. De novo assembly of the pennycress (Thlaspi arvense) transcriptome provides tools for the development of a winter cover crop and biodiesel feedstock

    PubMed Central

    Dorn, Kevin M; Fankhauser, Johnathon D; Wyse, Donald L; Marks, M David

    2013-01-01

    Field pennycress (Thlaspi arvense L.) has potential as an oilseed crop that may be grown during fall (autumn) and winter months in the Midwestern United States and harvested in the early spring as a biodiesel feedstock. There has been little agronomic improvement in pennycress through traditional breeding. Recent advances in genomic technologies allow for the development of genomic tools to enable rapid improvements to be made through genomic assisted breeding. Here we report an annotated transcriptome assembly for pennycress. RNA was isolated from representative plant tissues, and 203 million unique Illumina RNA-seq reads were produced and used in the transcriptome assembly. The draft transcriptome assembly consists of 33 873 contigs with a mean length of 1242 bp. A global comparison of homology between the pennycress and Arabidopsis transcriptomes, along with four other Brassicaceae species, revealed a high level of global sequence conservation within the family. The final assembly was functionally annotated, allowing for the identification of putative genes controlling important agronomic traits such as flowering and glucosinolate metabolism. Identification of these genes leads to testable hypotheses concerning their conserved function and to rational strategies to improve agronomic properties in pennycress. Future work to characterize isoform variation between diverse pennycress lines and develop a draft genome sequence for pennycress will further direct trait improvement. PMID:23786378

  17. HOST-SWITCHING DOES NOT CIRCUMVENT THE NI-BASED DEFENCE OF THE NI HYPERACCUMULATOR STREPTANTHUS POLYGALOIDES (BRASSICACEAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar concentration of heavy metals, such as nickel, may help defend metal --hyperaccumulating plants against both herbivores and pathogens. Host switching by generalist herbivores might be one strategy by which they can dilute lifetime consumption of toxic nickel. We examined the effects of host...

  18. Exogenous cytokinin treatments of a Ni hyper-accumulator, Alyssum murale, grown in a serpentine soil: Implications for phytoextraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Application of exogenous plant growth regulators was examined as a viable technique to increase the efficiency of plant metal phytoextraction from contaminated soils. The aim of this study was to investigate the alteration of Ni phytoextraction by Alyssum murale, a Ni hyperaccumulator, following the...

  19. Effects of arsenate, chromate, and sulfate on arsenic and chromium uptake and translocation by arsenic hyperaccumulator Pteris vittata L.

    E-print Network

    Ma, Lena

    Effects of arsenate, chromate, and sulfate on arsenic and chromium uptake and translocation 18 July 2013 Accepted 16 August 2013 Keywords: Phytoremediation Hyperaccumulator Arsenic Chromium and translocation by PV. Published by Elsevier Ltd. 1. Introduction Arsenic (As) and chromium (Cr) are both

  20. The potential of phytoremediation using hyperaccumulator plants: a case study at a lead-zinc mine site

    Microsoft Academic Search

    Bahareh Lorestani; Mehrdad Cheraghi; Nafiseh Yousefi

    2012-01-01

    Contamination with heavy metals is one of the most pressing threats to water and soil resources, as well as human health. Phytoremediation might potentially be used to remediate metal-contaminated sites. A major advance in the development of phytoremediation for heavy metal affected soils was the discovery of heavy metal hyperaccumulation in plants. This study applied several established criteria to identify

  1. Selenium biofortification of broccoli and carrots grown in soil amended with Se-enriched hyperaccumulator Stanleya pinnata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amending soils with Se-hyperaccumulator plant derived sources of selenium (Se) may be useful for increasing Se content in food crops in Se-deficient regions of the world. In this study, we evaluated total Se and the different chemical species of Se in broccoli and carrots grown in soils amended with...

  2. The hyperaccumulator Alyssum murale uses complexation with nitrogen and oxygen donor ligands for Ni transport and storage

    Microsoft Academic Search

    David H. McNear Jr; Rufus L. Chaney; Donald L. Sparks

    2009-01-01

    The Kotodesh genotype of the nickel (Ni) hyperaccumulator Alyssum murale was examined to determine the compartmentalization and internal speciation of Ni, and other elements, in an effort to ascertain the mechanism used by this plant to tolerate extremely high shoot (stem and leaf) Ni concentrations. Plants were grown either hydroponically or in Ni enriched soils from an area surrounding an

  3. Potential hyperaccumulation of Pb, Zn, Cu and Cd in endurant plants distributed in an old smeltery, northeast China

    NASA Astrophysics Data System (ADS)

    Cui, Shuang; Zhou, Qixing; Chao, Lei

    2007-01-01

    The absorption and accumulation of Pb, Zn, Cu and Cd in some endurant weed plant species that survived in an old smeltery in Liaoning, China, were systematically investigated. Potential hyperaccumulative characteristics of these species were also discussed. The results showed that metal accumulation in plants differed with species, tissues and metals. Endurant weed plants growing in this contaminated site exhibited high metal adaptability. Both the metal exclusion and detoxification tolerance strategies were involved in the species studied. Seven species for Pb and four species for Cd were satisfied for the concentration time level standard for hyperaccumulator. Considering translocation factor (TF) values, one species for Pb, seven species for Zn, two species for Cu and five species for Cd possessed the characteristic of hyperaccumulator. Particularly, Abutilon theophrasti Medic, exhibited strong accumulative ability to four heavy metals. Although enrichment coefficients of all samples were lesser than 1 and the absolute concentrations didn’t reach the standard, species mentioned above were primarily believed to be potential hyperaccumulators.

  4. Zinc and cadmium hyperaccumulation act as deterrents towards specialist herbivores and impede the performance of a generalist herbivore.

    PubMed

    Kazemi-Dinan, Ardeshir; Thomaschky, Sina; Stein, Ricardo J; Krämer, Ute; Müller, Caroline

    2014-04-01

    Extraordinarily high leaf metal concentrations in metal hyperaccumulator plants may serve as an elemental defence against herbivores. However, mixed results have been reported and studies using comparative approaches are missing. We investigated the deterrent and toxic potential of metals employing the hyperaccumulator Arabidopsis halleri. Effects of zinc (Zn) and cadmium (Cd) on the preferences of three Brassicaceae specialists were tested in paired-choice experiments using differently treated plant material, including transgenic plants. In performance tests, we determined the toxicity and joint effects of both metals incorporated in an artificial diet on the survival of a generalist. Feeding by all specialists was significantly reduced by metal concentrations from above 1000 ?g Zn g(-1) DW and 18 ?g Cd g(-1) DW. By contrast, metals did not affect oviposition. Generalist survival decreased with increasing concentrations of individual metals, whereby the combination of Zn and Cd had an additive toxic effect even at the lowest applied concentrations of 100 ?g Zn g(-1) and 2 ?g Cd g(-1) . Metal hyperaccumulation protects plants from herbivory resulting from deterrence and toxicity against a wide range of herbivores. The combination of metals exacerbates toxicity through joint effects and enhances elemental defence. Thus, metal hyperaccumulation is ecologically beneficial for plants. PMID:24383491

  5. Cellular Sequestration of Cadmium in the Hyperaccumulator Plant Species Sedum alfredii1[C][W

    PubMed Central

    Tian, Shengke; Lu, Lingli; Labavitch, John; Yang, Xiaoe; He, Zhenli; Hu, Hening; Sarangi, Ritimukta; Newville, Matt; Commisso, Joel; Brown, Patrick

    2011-01-01

    Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 ?g g?1 were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii. PMID:22025609

  6. Rhizosphere microbial densities and trace metal tolerance of the nickel hyperaccumulator Alyssum serpyllifolium subsp. lusitanicum.

    PubMed

    Becerra-Castro, C; Monterroso, C; García-Lestón, M; Prieto-Fernández, A; Acea, M J; Kidd, P S

    2009-08-01

    In this study we determine culturable microbial densities (total heterotrophs, ammonifiers, amylolytics and cellulolytics) and bacterial resistance to Co, Cr, and Ni in bulk and rhizosphere soils of three populations of the Ni-hyperaccumulator Alyssum serpyllifolium subsp. lusitanicum and the excluder Dactylis glomerata from ultramafic sites (two populations in Northeast (NE) Portugal (Samil (S), Morais (M)) and one population in Northwest (NW) Spain (Melide (L)). The relationship between bioavailable metal concentrations (H2O-soluble) and microbial densities were analysed. Significant differences in microbial densities and metal-resistance were observed between the two species and their three populations. The hyperaccumulator showed higher microbial densities (except cellulolytics) and a greater rhizosphere effect, but this was only observed in S and M populations. These populations of A. serpyllifolium also showed selective enrichment of Ni-tolerant bacteria at the rhizosphere where Ni solubility was enhanced (densities of Ni-resistant bacteria were positively correlated with H2O-soluble Ni). These rhizobacteria could solubilise Ni in the soil and potentially improve phytoextraction strategies. PMID:19810353

  7. Cellular Sequestration of Cadmium in the Hyperaccumulator Plant Species Sedum alfredii

    SciTech Connect

    Tian, Shengke; Lu, Lingli; Labavitch, John M.; Yang, Xiaoe; He, Zhenli; Hu, Hening; Sarangi, Ritimukta; Newville, Matt; Commisso, Joel; Brown, Patrick Hugh (UCD); (SLAC); (Zhejiang); (FSU); (UC)

    2012-07-23

    Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 {micro}g g{sup -1} were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii.

  8. Zinc adsorption and desorption characteristics in root cell wall involving zinc hyperaccumulation in Sedum alfredii Hance*

    PubMed Central

    Li, Ting-qiang; Yang, Xiao-e; Meng, Fan-hua; Lu, Ling-li

    2007-01-01

    Radiotracer techniques were employed to characterize 65Zn adsorption and desorption in root-cell-wall of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) species of Sedum alfredii Hance. The results indicated that at the end of a 30 min short time radioisotope loading period, comparable amounts of 65Zn were accumulated in the roots of the two ecotypes Sedum alfredii, whereas 2.1-fold more 65Zn remains in NHE root after 45-min desorption. At the end of 60 min uptake period, no difference of 65Zn accumulation was observed in undesorbed root-cell-wall of Sedum alfredii. However, 3.0-fold more 65Zn accumulated in desorbed root-cell-wall of NHE. Zn2+ binding in root-cell-wall preparations of NHE was greater than that in HE under high Zn2+ concentration. All these results suggested that root-cell-wall of the two ecotypes Sedum alfredii had the same ability to adsorb Zn2+, whereas the desorption characteristics were different, and with most of 65Zn binding on root of HE being available for loading into the xylem, as a result, more 65Zn was translocated to the shoot. PMID:17266186

  9. Hyperaccumulation of Pb, Zn and Cd in herbaceous grown on lead-zinc mining area in Yunnan, China.

    PubMed

    Yanqun, Zu; Yuan, Li; Jianjun, Chen; Haiyan, Chen; Li, Qin; Schvartz, Christian

    2005-07-01

    A field survey of herbaceous growing on lead-zinc mining area in Yunnan, China were conducted to identify species accumulating exceptionally large concentrations of Pb, Zn and Cd in shoots. In total, 220 plant samples of 129 species of 50 families and 220 soil samples in which the plants were growing were collected. According to accumulation concentration in plant shoots and the concentration time levels compared to plants from non-polluted environments, 21 plant samples of 16 species were chosen as best-performing specimens, 11 plant samples of 10 species for Pb, 5 plant samples of 4 species for Zn and 5 plant samples of 5 species for Cd. Sonchus asper (L.) Hill in Qilinkeng had hyperaccumulation capacity to Pb and Zn. Corydalis pterygopetala Franch in Paomaping had hyperaccumulation capacity to Zn and Cd. All 5 Cd hyperaccumulators came from Lanping lead-zinc mining area. Out of 11 Pb hyperaccumulators, 7 came from Minbingying of Huice lead-zinc mining area. The average of the concentration time levels compared to plants from non-polluted environments were higher than 10 times in all plant samples, the concentration time levels changed from 203 times to 620 times for Pb, from 50 times to 70 times for Zn and from 145 times to 330 times for Cd. Out of 21 plant samples, translocation factor changed from 0.35 to 1.90, only translocation factor of 7 plant samples were higher than 1. Enrichment coefficients of all samples were lower than 1. These plant species were primarily heavy metal hyperaccumulator, and will be used in phytoremediation of the metallic pollutants in soils after further research in accumulation mechanism. PMID:15910971

  10. Spatial Imaging, Speciation, and Quantification of Selenium in theHyperaccumulator Plants Astragalus bisulcatus and Stanleya pinnata

    SciTech Connect

    Freeman, J.L.; Zhang, L.H.; Marcus, M.A.; Fakra, S.; McGrath,S.P.; Pilon-Smits, E.A.H.

    2006-09-01

    Astragalus bisulcatus and Stanleya pinnata hyperaccumulate selenium (Se) up to 1% of plant dry weight. In the field, Se was mostly present in the young leaves and reproductive tissues of both hyperaccumulators. Microfocused scanning x-ray fluorescence mapping revealed that Se was hyperaccumulated in trichomes in young leaves of A. bisulcatus. None of 10 other elements tested were accumulated in trichomes. Micro x-ray absorption spectroscopy and liquid chromatography-mass spectrometry showed that Se in trichomes was present in the organic forms methylselenocysteine (MeSeCys; 53%) and {gamma}-glutamyl-MeSeCys (47%). In the young leaf itself, there was 30% inorganic Se (selenate and selenite) in addition to 70% MeSeCys. In young S. pinnata leaves, Se was highly concentrated near the leaf edge and surface in globular structures that were shown by energy-dispersive x-ray microanalysis to be mainly in epidermal cells. Liquid chromatography-mass spectrometry revealed both MeSeCys (88%) and selenocystathionine (12%) inside leaf edges. In contrast, both the Se accumulator Brassica juncea and the nonaccumulator Arabidopsis thaliana accumulated Se in their leaf vascular tissues and mesophyll cells. Se in hyperaccumulators appears to be mobile in both the xylem and phloem because Se-treated S. pinnata was found to be highly toxic to phloem-feeding aphids, and MeSeCys was present in the vascular tissues of a S. pinnata young leaf petiole as well as in guttation fluid. The compartmentation of organic selenocompounds in specific storage areas in the plant periphery appears to be a unique property of Se hyperaccumulators. The high concentration of Se in the plant periphery may contribute to Se tolerance and may also serve as an elemental plant defense mechanism.

  11. Spatial Imaging, Speciation, and Quantification of Selenium in the Hyperaccumulator Plants Astragalus bisulcatus and Stanleya pinnata1

    PubMed Central

    Freeman, John L.; Zhang, Li Hong; Marcus, Matthew A.; Fakra, Sirine; McGrath, Steve P.; Pilon-Smits, Elizabeth A.H.

    2006-01-01

    Astragalus bisulcatus and Stanleya pinnata hyperaccumulate selenium (Se) up to 1% of plant dry weight. In the field, Se was mostly present in the young leaves and reproductive tissues of both hyperaccumulators. Microfocused scanning x-ray fluorescence mapping revealed that Se was hyperaccumulated in trichomes in young leaves of A. bisulcatus. None of 10 other elements tested were accumulated in trichomes. Micro x-ray absorption spectroscopy and liquid chromatography-mass spectrometry showed that Se in trichomes was present in the organic forms methylselenocysteine (MeSeCys; 53%) and ?-glutamyl-MeSeCys (47%). In the young leaf itself, there was 30% inorganic Se (selenate and selenite) in addition to 70% MeSeCys. In young S. pinnata leaves, Se was highly concentrated near the leaf edge and surface in globular structures that were shown by energy-dispersive x-ray microanalysis to be mainly in epidermal cells. Liquid chromatography-mass spectrometry revealed both MeSeCys (88%) and selenocystathionine (12%) inside leaf edges. In contrast, both the Se accumulator Brassica juncea and the nonaccumulator Arabidopsis thaliana accumulated Se in their leaf vascular tissues and mesophyll cells. Se in hyperaccumulators appears to be mobile in both the xylem and phloem because Se-treated S. pinnata was found to be highly toxic to phloem-feeding aphids, and MeSeCys was present in the vascular tissues of a S. pinnata young leaf petiole as well as in guttation fluid. The compartmentation of organic selenocompounds in specific storage areas in the plant periphery appears to be a unique property of Se hyperaccumulators. The high concentration of Se in the plant periphery may contribute to Se tolerance and may also serve as an elemental plant defense mechanism. PMID:16920881

  12. Nickel Increases Susceptibility of a Nickel Hyperaccumulator to Turnip mosaic virus Micheal A. Davis,* John F. Murphy, and Robert S. Boyd

    E-print Network

    Boyd, Robert S.

    Nickel Increases Susceptibility of a Nickel Hyperaccumulator to Turnip mosaic virus Micheal A of this defense, however, has not been tested with a viral pathogen. Turnip mosaic virus (TuMV) accu- and Europe

  13. Current Biology 21, 14401449, September 13, 2011 2011 Elsevier Ltd All rights reserved DOI 10.1016/j.cub.2011.07.033 Selenium Hyperaccumulators Facilitate

    E-print Network

    growth and herbivory of Artemisia ludoviciana and Symphyotrichum ericoides as a function of their Se to hyperaccumulators, A. ludoviciana and S. ericoides contained 10- to 20-fold higher Se levels (800­2,000 mg kg21 DW

  14. Exploring the importance of sulfate transporters and ATP sulphurylases for selenium hyperaccumulation—a comparison of Stanleya pinnata and Brassica juncea (Brassicaceae)

    PubMed Central

    Schiavon, Michela; Pilon, Marinus; Malagoli, Mario; Pilon-Smits, Elizabeth A. H.

    2015-01-01

    Selenium (Se) hyperaccumulation, the capacity of some species to concentrate Se to levels upwards of 0.1% of dry weight, is an intriguing phenomenon that is only partially understood. Questions that remain to be answered are: do hyperaccumulators have one or more Se-specific transporters? How are these regulated by Se and sulfur (S)? In this study, hyperaccumulator Stanleya pinnata was compared with related non-hyperaccumulator Brassica juncea with respect to S-dependent selenate uptake and translocation, as well as for the expression levels of three sulfate/selenate transporters (Sultr) and three ATP sulphurylases (APS). Selenium accumulation went down ~10-fold with increasing sulfate supply in B. juncea, while S. pinnata only had a 2–3-fold difference in Se uptake between the highest (5 mM) and lowest sulfate (0 mM) treatments. The Se/S ratio was generally higher in the hyperaccumulator than the non-hyperaccumulator, and while tissue Se/S ratio in B. juncea largely reflected the ratio in the growth medium, S. pinnata enriched itself up to 5-fold with Se relative to S. The transcript levels of Sultr1;2 and 2;1 and APS1, 2, and 4 were generally much higher in S. pinnata than B. juncea, and the species showed differential transcript responses to S and Se supply. These results indicate that S. pinnata has at least one transporter with significant selenate specificity over sulfate. Also, the hyperaccumulator has elevated expression levels of several sulfate/selenate transporters and APS enzymes, which likely contribute to the Se hyperaccumulation and hypertolerance phenotype. PMID:25688247

  15. Exploring the importance of sulfate transporters and ATP sulphurylases for selenium hyperaccumulation-a comparison of Stanleya pinnata and Brassica juncea (Brassicaceae).

    PubMed

    Schiavon, Michela; Pilon, Marinus; Malagoli, Mario; Pilon-Smits, Elizabeth A H

    2015-01-01

    Selenium (Se) hyperaccumulation, the capacity of some species to concentrate Se to levels upwards of 0.1% of dry weight, is an intriguing phenomenon that is only partially understood. Questions that remain to be answered are: do hyperaccumulators have one or more Se-specific transporters? How are these regulated by Se and sulfur (S)? In this study, hyperaccumulator Stanleya pinnata was compared with related non-hyperaccumulator Brassica juncea with respect to S-dependent selenate uptake and translocation, as well as for the expression levels of three sulfate/selenate transporters (Sultr) and three ATP sulphurylases (APS). Selenium accumulation went down ~10-fold with increasing sulfate supply in B. juncea, while S. pinnata only had a 2-3-fold difference in Se uptake between the highest (5 mM) and lowest sulfate (0 mM) treatments. The Se/S ratio was generally higher in the hyperaccumulator than the non-hyperaccumulator, and while tissue Se/S ratio in B. juncea largely reflected the ratio in the growth medium, S. pinnata enriched itself up to 5-fold with Se relative to S. The transcript levels of Sultr1;2 and 2;1 and APS1, 2, and 4 were generally much higher in S. pinnata than B. juncea, and the species showed differential transcript responses to S and Se supply. These results indicate that S. pinnata has at least one transporter with significant selenate specificity over sulfate. Also, the hyperaccumulator has elevated expression levels of several sulfate/selenate transporters and APS enzymes, which likely contribute to the Se hyperaccumulation and hypertolerance phenotype. PMID:25688247

  16. Leaf-age and soil-plant relationships: key factors for reporting trace-elements hyperaccumulation by plants and design applications.

    PubMed

    Losfeld, Guillaume; L'Huillier, Laurent; Fogliani, Bruno; Coy, Stéphane Mc; Grison, Claude; Jaffré, Tanguy

    2015-04-01

    Relationships between the trace-elements (TE) content of plants and associated soil have been widely investigated especially to understand the ecology of TE hyperaccumulating species to develop applications using TE phytoextraction. Many studies have focused on the possibility of quantifying the soil TE fraction available to plants, and used bioconcentration (BC) as a measure of the plants ability to absorb TE. However, BC only offers a static view of the dynamic phenomenon of TE accumulation. Accumulation kinetics are required to fully account for TE distributions in plants. They are also crucial to design applications where maximum TE concentrations in plant leaves are needed. This paper provides a review of studies of BC (i.e. soil-plant relationships) and leaf-age in relation to TE hyperaccumulation. The paper focuses of Ni and Mn accumulators and hyperaccumulators from New Caledonia who were previously overlooked until recent Ecocatalysis applications emerged for such species. Updated data on Mn hyperaccumulators and accumulators from New Caledonia are also presented and advocate further investigation of the hyperaccumulation of this element. Results show that leaf-age should be considered in the design of sample collection and allowed the reclassification of Grevillea meisneri known previously as a Mn accumulator to a Mn hyperaccumulator. PMID:25138558

  17. Inoculation of selenium hyperaccumulator Stanleya pinnata and related non-accumulator Stanleya elata with hyperaccumulator rhizosphere fungi--investigation of effects on Se accumulation and speciation.

    PubMed

    Lindblom, Stormy Dawn; Fakra, Sirine C; Landon, Jessica; Schulz, Paige; Tracy, Ben; Pilon-Smits, Elizabeth A H

    2014-01-01

    Little is known about how fungi affect elemental accumulation in hyperaccumulators (HAs). Here, two rhizosphere fungi from selenium (Se) HA Stanleya pinnata, Alternaria seleniiphila (A1) and Aspergillus leporis (AS117), were used to inoculate S. pinnata and related non-HA Stanleya elata. Growth and Se and sulfur (S) accumulation were analyzed. Furthermore, X-ray microprobe analysis was used to investigate elemental distribution and speciation. Growth of S. pinnata was not affected by inoculation or by Se. Stanleya elata growth was negatively affected by AS117 and by Se, but combination of both did not reduce growth. Selenium translocation was reduced in inoculated S. pinnata, and inoculation reduced S translocation in both species. Root Se distribution and speciation were not affected by inoculation in either species; both species accumulated mainly (90%) organic Se. Sulfur, in contrast, was present equally in organic and inorganic forms in S. pinnata roots. Thus, these rhizosphere fungi can affect growth and Se and/or S accumulation, depending on host species. They generally enhanced root accumulation and reduced translocation. These effects cannot be attributed to altered plant Se speciation but may involve altered rhizosphere speciation, as these fungi are known to produce elemental Se. Reduced Se translocation may be useful in applications where toxicity to herbivores and movement of Se into the food chain is a concern. The finding that fungal inoculation can enhance root Se accumulation may be useful in Se biofortification or phytoremediation using root crop species. PMID:24032473

  18. Selenium uptake by edible oyster mushrooms (Pleurotus sp.) from selenium-hyperaccumulated wheat straw.

    PubMed

    Bhatia, Poonam; Prakash, Ranjana; Prakash, N Tejo

    2013-01-01

    In an effort to produce selenium (Se)-fortifying edible mushrooms, five species of oyster mushroom (Pleurotus sp.), were cultivated on Se-rich wheat straw collected from a seleniferous belt of Punjab, India. Total selenium was analyzed in the selenium hyperaccumulated wheat straw and the fruiting bodies. Significantly high levels (p<0.0001) of Se uptake were observed in fruiting bodies of all mushrooms grown on Se-rich wheat straw. To the best of our knowledge, accumulation and quantification of selenium in mushrooms has hitherto not been reported with substrates naturally enriched with selenium. The results demonstrate the potential of selenium-rich agricultural residues as substrates for production of Se-enriched mushrooms and the ability of different species of oyster mushrooms to absorb and fortify selenium. The study envisages potential use of selenium-rich agricultural residues towards cultivation of Se-enriched mushrooms for application in selenium supplementation or neutraceutical preparations. PMID:23535542

  19. X-ray absorption spectroscopy at the Ni-K edge in Stackhousia tryonii Bailey hyperaccumulator

    SciTech Connect

    Ionescu, Mihail; Bhatia, Naveen P.; Cohen , David D.; Siegele, R.; Marcus, Matthew A.; Fakra, Sirine C.; Foran, G.; Kachenko, A.

    2007-10-08

    Young plants of Stackhousia tryonii Bailey were exposed to 34 mM Ni kg-1 in the form of NiSO4- 6H2O solution and grown under controlled glasshouse conditions for a period of 20 days. Fresh leaf, stem and root samples were analysed in vivo by micro x-ray absorption spectroscopy (XAS) at the Ni-K edge.Both x-ray absorption near edge structure and extended x-ray absorption fine structure spectra were analysed, and theresulting spectra were compared with spectra obtained from nine biologically important Ni-containing model compounds. The results revealed that themajority of leaf, stem and root Ni in the hyperaccumulator was chelated by citrate.Our results also suggest that in leavesNi is complexed by phosphate and histidine, and in stems and roots, phytate and histidine. The XAS results provide an important physiological insightinto transport, detoxification and storage of Ni in S. tryonii plants.

  20. Repeated phytoextraction of four metal-contaminated soils using the cadmium/zinc hyperaccumulator Sedum plumbizincicola.

    PubMed

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Zhang, Hao; Christie, Peter

    2014-06-01

    A cadmium/zinc hyperaccumulator extracted metals from four contaminated soils over three years in a glasshouse experiment. Changes in plant metal uptake and soil total (aqua regia-extractable) and available metals were investigated. Plant Cd concentrations in a high-Cd acid soil and plant Zn concentrations in two acid soils decreased during repeated phytoextraction and were predicted by soil available metal concentrations. However, on repeated phytoextraction, plant Cd concentrations remained constant in lightly Cd-polluted acid soils, as did plant Cd and Zn in alkaline soils, although soil available metal concentrations decreased markedly. After phytoextraction acid soils showed much higher total metal removal efficiencies, indicating possible suitability of phytoextraction for acid soils. However, DGT-testing, which takes soil metal re-supply into consideration, showed substantial removal of available metal and distinct decreases in metal supply capacity in alkaline soils after phytoextraction, suggesting that a strategy based on lowering the bioavailable contaminant might be feasible. PMID:24675367

  1. Phytoremediation of uranium-contaminated soils: Role of organic acids in triggering uranium hyperaccumulation in plants

    SciTech Connect

    Huang, J.W.; Blaylock, M.J.; Kapulnik, Y.; Ensley, B.D. [Phytotech Inc., Monmouth Junction, NJ (United States)] [Phytotech Inc., Monmouth Junction, NJ (United States)

    1998-07-01

    Uranium phytoextraction, the use of plants to extract U from contaminated soils, is an emerging technology. The authors report on the development of this technology for the cleanup of U-contaminated soils. In this research, they investigated the effects of various soil amendments on U desorption from soil to soil solution, studied the physiological characteristics of U uptake and accumulation in plants, and developed techniques to trigger U hyperaccumulation in plants. A key to the success of U phytoextraction is to increase soil U availability to plants. The authors have found that some organic acids can be added to soils to increase U desorption from soil to soil solution and to trigger a rapid U accumulation in plants. Of the organic acids (acetic acid, citric acid, and malic acid) tested, citric acid was the most effective in enhancing U accumulation in plants. Shoot U concentrations of Brassica juncea and Brassica chinensis grown in a U-contaminated soil increased from less than 5 mg kg{sup {minus}1} to more than 5,000 mg kg{sup {minus}1} in citric acid-treated soils. To their knowledge, this is the highest shoot U concentration reported for plants grown on U-contaminated soils. Using this U hyperaccumulation technique, they are now able to increase U accumulation in shoots of selected plant species grown in two U-contaminated soils by more than 1,000-fold within a few days. The results suggest that U phytoextraction may provide an environmentally friendly alternative for the cleanup of U-contaminated soils.

  2. Mechanisms of Arsenic Hyperaccumulation in Pteris vittata. Uptake Kinetics, Interactions with Phosphate, and Arsenic Speciation1

    PubMed Central

    Wang, Junru; Zhao, Fang-Jie; Meharg, Andrew A.; Raab, Andrea; Feldmann, Joerg; McGrath, Steve P.

    2002-01-01

    The mechanisms of arsenic (As) hyperaccumulation in Pteris vittata, the first identified As hyperaccumulator, are unknown. We investigated the interactions of arsenate and phosphate on the uptake and distribution of As and phosphorus (P), and As speciation in P. vittata. In an 18-d hydroponic experiment with varying concentrations of arsenate and phosphate, P. vittata accumulated As in the fronds up to 27,000 mg As kg?1 dry weight, and the frond As to root As concentration ratio varied between 1.3 and 6.7. Increasing phosphate supply decreased As uptake markedly, with the effect being greater on root As concentration than on shoot As concentration. Increasing arsenate supply decreased the P concentration in the roots, but not in the fronds. Presence of phosphate in the uptake solution decreased arsenate influx markedly, whereas P starvation for 8 d increased the maximum net influx by 2.5-fold. The rate of arsenite uptake was 10% of that for arsenate in the absence of phosphate. Neither P starvation nor the presence of phosphate affected arsenite uptake. Within 8 h, 50% to 78% of the As taken up was distributed to the fronds, with a higher translocation efficiency for arsenite than for arsenate. In fronds, 49% to 94% of the As was extracted with a phosphate buffer (pH 5.6). Speciation analysis using high-performance liquid chromatography-inductively coupled plasma mass spectroscopy showed that >85% of the extracted As was in the form of arsenite, and the remaining mostly as arsenate. We conclude that arsenate is taken up by P. vittata via the phosphate transporters, reduced to arsenite, and sequestered in the fronds primarily as As(III). PMID:12428020

  3. Ultrastructural changes, zinc hyperaccumulation and its relation with antioxidants in two ecotypes of Sedum alfredii Hance.

    PubMed

    Jin, Xiao Fen; Yang, Xiao E; Islam, Ejazul; Liu, Dan; Mahmood, Qaisar; Li, Hong; Li, Junying

    2008-11-01

    Zn phytotoxicity and its possible detoxifying responses in two ecotypes of Sedum alfredii Hance, i.e. hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) were investigated. HE grew better with high Zn concentrations of 29.11gkg(-1) DW in shoots when exposed to 500microM Zn2+. Toxicity symptoms caused by Zn in root cells of both ecotypes mainly included plasmolysis, disruption of plasma membranes and increased cell vacuolation. At high supplied Zn concentration, chloroplasts suffered from structural disorganization in both ecotypes. Zn-induced hydrogen peroxide (H2O2) and superoxide radical (O(2)-) productions in leaves were determined by a histochemical method, which revealed that Zn stress may have involved NADPH oxidase, protein phosphatases and intracellular Ca2+ to activate the reactive oxygen species production. Inhibition of glutathione synthesis may have led to increased H2O2 and O(2)- accumulations in leaves of HE. In response to higher Zn concentrations, ascorbic acid significantly increased in both ecotypes and levels of glutathione increased in both leaves and roots of HE and in roots of NHE without any change in the leaves of NHE. The enzymatic activities like those of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), guaiacol peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.6.4.2) in leaves of HE were all enhanced at supplied Zn concentration of 500microM, which may account for its better growth. PMID:18693116

  4. A comprehensive set of transcript sequences of the heavy metal hyperaccumulator Noccaea caerulescens

    PubMed Central

    Lin, Ya-Fen; Severing, Edouard I.; te Lintel Hekkert, Bas; Schijlen, Elio; Aarts, Mark G. M.

    2014-01-01

    Noccaea caerulescens is an extremophile plant species belonging to the Brassicaceae family. It has adapted to grow on soils containing high, normally toxic, concentrations of metals such as nickel, zinc, and cadmium. Next to being extremely tolerant to these metals, it is one of the few species known to hyperaccumulate these metals to extremely high concentrations in their aboveground biomass. In order to provide additional molecular resources for this model metal hyperaccumulator species to study and understand the mechanism of adaptation to heavy metal exposure, we aimed to provide a comprehensive database of transcript sequences for N. caerulescens. In this study, 23,830 transcript sequences (isotigs) with an average length of 1025 bp were determined for roots, shoots and inflorescences of N. caerulescens accession “Ganges” by Roche GS-FLEX 454 pyrosequencing. These isotigs were grouped into 20,378 isogroups, representing potential genes. This is a large expansion of the existing N. caerulescens transcriptome set consisting of 3705 unigenes. When translated and compared to a Brassicaceae proteome set, 22,232 (93.2%) of the N. caerulescens isotigs (corresponding to 19,191 isogroups) had a significant match and could be annotated accordingly. Of the remaining sequences, 98 isotigs resembled non-plant sequences and 1386 had no significant similarity to any sequence in the GenBank database. Among the annotated set there were many isotigs with similarity to metal homeostasis genes or genes for glucosinolate biosynthesis. Only for transcripts similar to Metallothionein3 (MT3), clear evidence for an additional copy was found. This comprehensive set of transcripts is expected to further contribute to the discovery of mechanisms used by N. caerulescens to adapt to heavy metal exposure. PMID:24999345

  5. Please cite this article in press as: Lindblom, S.D., et al., Influence of microbial associations on selenium localization and speciation in roots of Astragalus and Stanleya hyperaccumulators. Environ. Exp. Bot. (2012), doi:10.1016/j.envexpbot.2011.12.011

    E-print Network

    on selenium localization and speciation in roots of Astragalus and Stanleya hyperaccumulators. Environ. Exp associations on selenium localization and speciation in roots of Astragalus and Stanleya hyperaccumulators distribu- tion of Se in roots of Astragalus and Stanleya hyperaccumulators. Selenium was present throughout

  6. Differential generation of hydrogen peroxide upon exposure to zinc and cadmium in the hyperaccumulating plant specie (Sedum alfredii Hance)*

    PubMed Central

    Chao, Yue-en; Zhang, Min; Tian, Sheng-ke; Lu, Ling-li; Yang, Xiao-e

    2008-01-01

    Sedum alfredii Hance has been identified as zinc (Zn) and cadmium (Cd) co-hyperaccumulator. In this paper the relationships of Zn or Cd hyperaccumulation to the generation and the role of H2O2 in Sedum alfredii H. were examined. The results show that Zn and Cd contents in the shoots of Sedum alfredii H. treated with 1000 ?mol/L Zn2+ and/or 200 ?mol/L Cd2+ increased linearly within 15 d. Contents of total S, glutathione (GSH) and H2O2 in shoots also increased within 15 d, and then decreased. Total S and GSH contents in shoots were higher under Cd2+ treatment than under Zn2+ treatment. However, reverse trends of H2O2 content in shoots were obtained, in which much higher H2O2 content was observed in Zn2+-treated shoots than in Cd2+-treated shoots. Similarly, the microscopic imaging of H2O2 accumulation in leaves using H2O2 probe technique showed that much higher H2O2 accumulation was observed in the Zn2+-treated leaf than in the Cd2+-treated one. These results suggest that there are different responses in the generation of H2O2 upon exposure to Zn2+ and Cd2+ for the hyperaccumulator Sedum alfredii H. And this is the first report that the generation of H2O2 may play an important role in Zn hyperaccumulation in the leaves. Our results also imply that GSH may play an important role in the detoxification of dissociated Zn/Cd and the generation of H2O2. PMID:18357627

  7. Arsenic species in an arsenic hyperaccumulating fern, Pityrogramma calomelanos: a potential phytoremediator of arsenic-contaminated soils

    Microsoft Academic Search

    Kevin Francesconi; Pornsawan Visoottiviseth; Weeraphan Sridokchan; Walter Goessler

    2002-01-01

    The fern Pityrogramma calomelanos is a hyperaccumulator of arsenic that grows readily on arsenic-contaminated soils in the Ron Phibun district of southern Thailand. P. calomelanos accumulates arsenic mostly in the fronds (up to 8350 ?g As g?1 dry mass) while the rhizoids contain the lowest concentrations of arsenic (88–310 ?g As g?1 dry mass). The arsenic species in aqueous extracts

  8. Zinc compartmentation in root, transport into xylem, and absorption into leaf cells in the hyperaccumulating species of Sedum alfredii Hance

    Microsoft Academic Search

    Xiaoe Yang; Tingqiang Li; Juncheng Yang; Zhenli He; Lingli Lu; Fanhua Meng

    2006-01-01

    Sedum alfredii Hance can accumulate Zn in shoots over 2%. Leaf and stem Zn concentrations of the hyperaccumulating ecotype (HE) were 24- and 28-fold higher, respectively, than those of the nonhyperaccumulating ecotype (NHE), whereas 1.4-fold more Zn was accumulated in the roots of the NHE. Approximately 2.7-fold more Zn was stored in the root vacuoles of the NHE, and thus

  9. Isolation and characterization endophytic bacteria from hyperaccumulator Sedum alfredii Hance and their potential to promote phytoextraction of zinc polluted soil

    Microsoft Academic Search

    Long Xinxian; Chen Xuemei; Chen Yagang; Wong Jonathan Woon-Chung; Wei Zebin; Wu Qitang

    2011-01-01

    The aim of this study was to isolate and characterize endophytic bacteria from roots, stems and leaves of Zn\\/Cd hyperaccumulator\\u000a Sedum alfredii. Endophytic bacteria were observed in roots, stems and leave of S. alfredii, with a significantly higher density in roots, followed by leave and stems. A total of fourteen bacterial endophytes were\\u000a isolated and are closely related phylogenetically to

  10. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola.

    PubMed

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Christie, Peter

    2013-10-15

    Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 ?M Cu), 5-50 ?M Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 ?M induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 ?M Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola. PMID:23959253

  11. Selection of salt and boron tolerant selenium hyperaccumulator Stanleya pinnata genotypes and characterization of Se phytoremediation from agricultural drainage sediments.

    PubMed

    Freeman, John L; Bañuelos, Gary S

    2011-11-15

    Genetic variation in salt (Na(2)SO(4), NaCl) and boron (B) tolerance among four ecotypes of the selenium (Se) hyperaccumulator Stanleya pinnata (Pursh) Britton was utilized to select tolerant genotypes capable of phytoremediating Se from salt, B, and Se-laden agricultural drainage sediment. The few individual salt/B tolerant genotypes were successfully selected from among a large population of highly salt/B sensitive seedlings. The distribution, hyperaccumulation, and volatilization of Se were then examined in selected plants capable of tolerating the high salt/B laden drainage sediment. Salt/B tolerant genotypes from each of the four ecotypes had mean Se concentrations ranging from 2510 ± 410 to 1740 ± 620 in leaves and 3180 ± 460 to 2500 ± 1060 in seeds (?g Se g(-1) DW ± SD), while average daily Se volatilization rates ranged from 722 ± 375 to 1182 ± 575 (?g Se m(-2) d(-1) ± SD). After two growing seasons (?18 months), we estimated that hyperaccumulation and volatilization of Se by tolerant S. pinnata genotypes and their associated microbes can remove approximately 30% of the total soil Se in 0-30 cm sediment. The salt/B tolerant S. pinnata genotypes selected and characterized herein represent promising new tools for the successful phytoremediation of Se from salt/B and Se-laden agricultural drainage sediments. PMID:21988205

  12. TU & MA: ARSENIC UPTAKE BY THE HYPERACCUMULATOR LADDER BRAKE 641 reproductive growth of simulated and field-grown soybean. I. Seed-dynamics of N2-fixing, field-growing Alnus glutinosa under elevated

    E-print Network

    Ma, Lena

    TU & MA: ARSENIC UPTAKE BY THE HYPERACCUMULATOR LADDER BRAKE 641 reproductive growth of simulated and nitrogen Effects of Arsenic Concentrations and Forms on Arsenic Uptake by the Hyperaccumulator Ladder Brake of arsenic-contaminated soils has thus become aLadder brake (Pteris vittata L.) is a newly discovered arsenic

  13. Characterization of arsenic-resistant endophytic bacteria from hyperaccumulators Pteris vittata and Pteris multifida.

    PubMed

    Zhu, Ling-Jia; Guan, Dong-Xing; Luo, Jun; Rathinasabapathi, Bala; Ma, Lena Q

    2014-10-01

    We isolated and characterized As-resistant endophytic bacteria (AEB) from two arsenic hyperaccumulators. Their plant growth promoting traits and the relation between As tolerance and transformation were evaluated. A total of 41 and 33 AEB were isolated from Pteris vittata (PV) and Pteris multifida (PM) respectively. PV AEB represented 2genera while PM AEB comprised of 12 genera, with Bacillus sp. being the most dominant bacteria from both plants. All AEB had limited ability in solubilizing P and producing indole acetic acid (IAA) and siderophore. All isolates tolerated 10mM arsenate (As(V)), with PV isolates being more tolerant to As(V) and PM more tolerant to arsenite (As(III)). Bacterial arsenic tolerance was related to their ability in As(III) oxidation and As(V) reduction as well as their ability to retain As in the biomass to a varying extent. Though AEB showed limited plant growth promoting traits, they were important in arsenic tolerance and speciation in plants. PMID:25065783

  14. Accumulation and distribution characteristics of zinc and cadmium in the hyperaccumulator plant Sedum plumbizincicola.

    PubMed

    Cao, Dong; Zhang, Hongzheng; Wang, Yaodong; Zheng, Leina

    2014-08-01

    Accumulation and distribution of Zn and Cd in the hyperaccumulator plant Sedum plumbizincicola were investigated in a hydroponic experiment. Mean Cd and Zn concentrations in shoots (7,010 and 18,400 mg kg(-1)) were about sevenfold and fivefold higher than those in roots (840 and 3,000 mg kg(-1)) after exposure to 100 ?M CdSO4 and 600 ?M ZnSO4, respectively. Cd and Zn concentrations in young leaves (4,330 and 9,820 mg kg(-1)) were about sixfold and twofold higher than those in mature leaves (636 and 2,620 mg kg(-1)), respectively. MicroPIXE analysis showed that Zn was predominantly localized in epidermal cells in both young and mature leaves, but large amounts of Zn occurred in mesophyll cells in young leaves. Leaf tissue fractionation showed that soluble and cell wall fractions were different at the two stages of leaf growth. Young and mature leaves of S. plumbizincicola also showed different accumulation and distribution characteristics for Zn and Cd. PMID:24789526

  15. The variation of root exudates from the hyperaccumulator Sedum alfredii under cadmium stress: metabonomics analysis.

    PubMed

    Luo, Qing; Sun, Lina; Hu, Xiaomin; Zhou, Ruiren

    2014-01-01

    Hydroponic experiments were conducted to investigate the variation of root exudates from the hyperaccumulator Sedum alfredii under the stress of cadmium (Cd). S. alfredii was cultured for 4 days in the nutrient solution spiked with CdCl2 at concentrations of 0, 5, 10, 40, and 400 µM Cd after the pre-culture. The root exudates were collected and analyzed by GC-MS, and 62 compounds were identified. Of these compounds, the orthogonal partial least-squares discrimination analysis (OPLS-DA) showed that there were a distinct difference among the root exudates with different Cd treatments and 20 compounds resulting in this difference were found out. Changing tendencies in the relative content of these 20 compounds under the different Cd treatments were analyzed. These results indicated that trehalose, erythritol, naphthalene, d-pinitol and n-octacosane might be closely related to the Cd stabilization, phosphoric acid, tetradecanoic acid, oxalic acid, threonic acid and glycine could be attributed to the Cd mobilization, and mannitol, oleic acid, 3-hydroxybutanoic acid, fructose, octacosanol and ribitol could copy well with the Cd stress. PMID:25545686

  16. The Variation of Root Exudates from the Hyperaccumulator Sedum alfredii under Cadmium Stress: Metabonomics Analysis

    PubMed Central

    Luo, Qing; Sun, Lina; Hu, Xiaomin; Zhou, Ruiren

    2014-01-01

    Hydroponic experiments were conducted to investigate the variation of root exudates from the hyperaccumulator Sedum alfredii under the stress of cadmium (Cd). S. alfredii was cultured for 4 days in the nutrient solution spiked with CdCl2 at concentrations of 0, 5, 10, 40, and 400 µM Cd after the pre-culture. The root exudates were collected and analyzed by GC-MS, and 62 compounds were identified. Of these compounds, the orthogonal partial least-squares discrimination analysis (OPLS-DA) showed that there were a distinct difference among the root exudates with different Cd treatments and 20 compounds resulting in this difference were found out. Changing tendencies in the relative content of these 20 compounds under the different Cd treatments were analyzed. These results indicated that trehalose, erythritol, naphthalene, d-pinitol and n-octacosane might be closely related to the Cd stabilization, phosphoric acid, tetradecanoic acid, oxalic acid, threonic acid and glycine could be attributed to the Cd mobilization, and mannitol, oleic acid, 3-hydroxybutanoic acid, fructose, octacosanol and ribitol could copy well with the Cd stress. PMID:25545686

  17. Selenium hyperaccumulator plants Stanleya pinnata and Astragalus bisulcatus are colonized by Se-resistant, Se-excluding wasp and beetle seed herbivores.

    PubMed

    Freeman, John L; Marcus, Matthew A; Fakra, Sirine C; Devonshire, Jean; McGrath, Steve P; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2012-01-01

    Selenium (Se) hyperaccumulator plants can concentrate the toxic element Se up to 1% of shoot (DW) which is known to protect hyperaccumulator plants from generalist herbivores. There is evidence for Se-resistant insect herbivores capable of feeding upon hyperaccumulators. In this study, resistance to Se was investigated in seed chalcids and seed beetles found consuming seeds inside pods of Se-hyperaccumulator species Astragalus bisulcatus and Stanleya pinnata. Selenium accumulation, localization and speciation were determined in seeds collected from hyperaccumulators in a seleniferous habitat and in seed herbivores. Astragalus bisulcatus seeds were consumed by seed beetle larvae (Acanthoscelides fraterculus Horn, Coleoptera: Bruchidae) and seed chalcid larvae (Bruchophagus mexicanus, Hymenoptera: Eurytomidae). Stanleya pinnata seeds were consumed by an unidentified seed chalcid larva. Micro X-ray absorption near-edge structure (µXANES) and micro-X-Ray Fluorescence mapping (µXRF) demonstrated Se was mostly organic C-Se-C forms in seeds of both hyperaccumulators, and S. pinnata seeds contained ?24% elemental Se. Liquid chromatography-mass spectrometry of Se-compounds in S. pinnata seeds detected the C-Se-C compound seleno-cystathionine while previous studies of A. bisulcatus seeds detected the C-Se-C compounds methyl-selenocysteine and ?-glutamyl-methyl-selenocysteine. Micro-XRF and µXANES revealed Se ingested from hyperaccumulator seeds redistributed throughout seed herbivore tissues, and portions of seed C-Se-C were biotransformed into selenocysteine, selenocystine, selenodiglutathione, selenate and selenite. Astragalus bisulcatus seeds contained on average 5,750 µg Se g(-1), however adult beetles and adult chalcid wasps emerging from A. bisulcatus seed pods contained 4-6 µg Se g(-1). Stanleya pinnata seeds contained 1,329 µg Se g(-1) on average; however chalcid wasp larvae and adults emerging from S. pinnata seed pods contained 9 and 47 µg Se g(-1). The results suggest Se resistant seed herbivores exclude Se, greatly reducing tissue accumulation; this explains their ability to consume high-Se seeds without suffering toxicity, allowing them to occupy the unique niche offered by Se hyperaccumulator plants. PMID:23226523

  18. Selenium Hyperaccumulator Plants Stanleya pinnata and Astragalus bisulcatus Are Colonized by Se-Resistant, Se-Excluding Wasp and Beetle Seed Herbivores

    PubMed Central

    Freeman, John L.; Marcus, Matthew A.; Fakra, Sirine C.; Devonshire, Jean; McGrath, Steve P.; Quinn, Colin F.; Pilon-Smits, Elizabeth A. H.

    2012-01-01

    Selenium (Se) hyperaccumulator plants can concentrate the toxic element Se up to 1% of shoot (DW) which is known to protect hyperaccumulator plants from generalist herbivores. There is evidence for Se-resistant insect herbivores capable of feeding upon hyperaccumulators. In this study, resistance to Se was investigated in seed chalcids and seed beetles found consuming seeds inside pods of Se-hyperaccumulator species Astragalus bisulcatus and Stanleya pinnata. Selenium accumulation, localization and speciation were determined in seeds collected from hyperaccumulators in a seleniferous habitat and in seed herbivores. Astragalus bisulcatus seeds were consumed by seed beetle larvae (Acanthoscelides fraterculus Horn, Coleoptera: Bruchidae) and seed chalcid larvae (Bruchophagus mexicanus, Hymenoptera: Eurytomidae). Stanleya pinnata seeds were consumed by an unidentified seed chalcid larva. Micro X-ray absorption near-edge structure (µXANES) and micro-X-Ray Fluorescence mapping (µXRF) demonstrated Se was mostly organic C-Se-C forms in seeds of both hyperaccumulators, and S. pinnata seeds contained ?24% elemental Se. Liquid chromatography–mass spectrometry of Se-compounds in S. pinnata seeds detected the C-Se-C compound seleno-cystathionine while previous studies of A. bisulcatus seeds detected the C-Se-C compounds methyl-selenocysteine and ?-glutamyl-methyl-selenocysteine. Micro-XRF and µXANES revealed Se ingested from hyperaccumulator seeds redistributed throughout seed herbivore tissues, and portions of seed C-Se-C were biotransformed into selenocysteine, selenocystine, selenodiglutathione, selenate and selenite. Astragalus bisulcatus seeds contained on average 5,750 µg Se g?1, however adult beetles and adult chalcid wasps emerging from A. bisulcatus seed pods contained 4–6 µg Se g?1. Stanleya pinnata seeds contained 1,329 µg Se g?1 on average; however chalcid wasp larvae and adults emerging from S. pinnata seed pods contained 9 and 47 µg Se g?1. The results suggest Se resistant seed herbivores exclude Se, greatly reducing tissue accumulation; this explains their ability to consume high-Se seeds without suffering toxicity, allowing them to occupy the unique niche offered by Se hyperaccumulator plants. PMID:23226523

  19. Arsenic hyperaccumulation by Pteris vittata from arsenic contaminated soils and the effect of liming and phosphate fertilisation.

    PubMed

    Caille, N; Swanwick, S; Zhao, F J; McGrath, S P

    2004-11-01

    Pot experiments were carried out to investigate the potential of phytoremediation with the arsenic hyperaccumulator Pteris vittata in a range of soils contaminated with As and other heavy metals, and the influence of phosphate and lime additions on As hyperaccumulation by P. vittata. The fern was grown in 5 soils collected from Cornwall (England) containing 67-4550 mg As kg(-1) and different levels of metals. All soils showed a similar distribution pattern of As in different fractions in a sequential extraction, with more than 60% of the total As being associated with the fraction thought to represent amorphous and poorly-crystalline hydrous oxides of Fe and Al. The concentration of As in the fronds ranged from 84 to 3600 mg kg(-1), with 0.9-3.1% of the total soil As being taken up by P. vittata. In one soil which contained 5500 mg Cu kg(-1) and 1242 mg Zn kg(-1), P. vittata suffered from phytotoxicity and accumulated little As (0.002% of total). In a separate experiment, neither phosphate addition (50mg P kg(-1) soil) nor liming (4.6 g CaCO3 kg(-1) soil) was found to affect the As concentration in the fronds of P. vittata, even though phosphate addition increased the As concentration in the soil pore water. Between 4 and 7% of the total soil As was taken up by P. vittata in 4 cuttings in this experiment. The results indicate that P. vittata can hyperaccumulate As from naturally contaminated soils, but may be suitable for phytoremediation only in the moderately contaminated soils. PMID:15276279

  20. Lewis acid catalysis and Green oxidations: sequential tandem oxidation processes induced by Mn-hyperaccumulating plants.

    PubMed

    Escande, Vincent; Renard, Brice-Loïc; Grison, Claude

    2014-09-30

    Among the phytotechnologies used for the reclamation of degraded mining sites, phytoextraction aims to diminish the concentration of polluting elements in contaminated soils. However, the biomass resulting from the phytoextraction processes (highly enriched in polluting elements) is too often considered as a problematic waste. The manganese-enriched biomass derived from native Mn-hyperaccumulating plants of New Caledonia was presented here as a valuable source of metallic elements of high interest in chemical catalysis. The preparation of the catalyst Eco-Mn1 and reagent Eco-Mn2 derived from Grevillea exul exul and Grevillea exul rubiginosa was investigated. Their unusual polymetallic compositions allowed to explore new reactivity of low oxidative state of manganese-Mn(II) for Eco-Mn1 and Mn(IV) for Eco-Mn2. Eco-Mn1 was used as a Lewis acid to catalyze the acetalization/elimination of aldehydes into enol ethers with high yields; a new green and stereoselective synthesis of (-)-isopulegol via the carbonyl-ene cyclization of (+)-citronellal was also performed with Eco-Mn1. Eco-Mn2 was used as a mild oxidative reagent and controlled the oxidation of aliphatic alcohols into aldehydes with quantitative yields. Oxidative cleavage was interestingly noticed when Eco-Mn2 was used in the presence of a polyol. Eco-Mn2 allowed direct oxidative iodination of ketones without using iodine, which is strongly discouraged by new environmental legislations. Finally, the combination of the properties in the Eco-Mn catalysts and reagents gave them an unprecedented potential to perform sequential tandem oxidation processes through new green syntheses of p-cymene from (-)-isopulegol and (+)-citronellal; and a new green synthesis of functionalized pyridines by in situ oxidation of 1,4-dihydropyridines. PMID:25263417

  1. Daclatasvir inhibits hepatitis C virus NS5A motility and hyper-accumulation of phosphoinositides.

    PubMed

    Chukkapalli, Vineela; Berger, Kristi L; Kelly, Sean M; Thomas, Meryl; Deiters, Alexander; Randall, Glenn

    2015-02-01

    Combinations of direct-acting antivirals (DAAs) against the hepatitis C virus (HCV) have the potential to revolutionize the HCV therapeutic regime. An integral component of DAA combination therapies is HCV NS5A inhibitors. It has previously been proposed that NS5A DAAs inhibit two functions of NS5A: RNA replication and virion assembly. In this study, we characterize the impact of a prototype NS5A DAA, daclatasvir (DCV), on HCV replication compartment formation. DCV impaired HCV replicase localization and NS5A motility. In order to characterize the mechanism behind altered HCV replicase localization, we examined the impact of DCV on the interaction of NS5A with its essential cellular cofactor, phosphatidylinositol-4-kinase III ? (PI4KA). We observed that DCV does not inhibit PI4KA directly, nor does it impair early events of the NS5A-PI4KA interaction that can occur when NS5A is expressed alone. NS5A functions that are unaffected by DCV include PI4KA binding, as determined by co-immunoprecipitation, and a basal accumulation of the PI4KA product, PI4P. However, DCV impairs late steps in PI4KA activation that requires NS5A expressed in the context of the HCV polyprotein. These NS5A functions include hyper-stimulation of PI4P levels and appropriate replication compartment formation. The data are most consistent with a model wherein DCV inhibits conformational changes in the NS5A protein or protein complex formations that occur in the context of HCV polyprotein expression and stimulate PI4P hyper-accumulation and replication compartment formation. PMID:25546252

  2. Chromate and phosphate inhibited each other's uptake and translocation in arsenic hyperaccumulator Pteris vittata L.

    PubMed

    de Oliveira, Letúzia M; Lessl, Jason T; Gress, Julia; Tisarum, Rujira; Guilherme, Luiz R G; Ma, Lena Q

    2015-02-01

    We investigated the effects of chromate (CrVI) and phosphate (P) on their uptake and translocation in As-hyperaccumulator Pteris vittata (PV). Plants were exposed to 1) 0.10 mM CrVI and 0, 0.25, 1.25, or 2.50 mM P or 2) 0.25 mM P and 0, 0.50, 2.5 or 5.0 mM CrVI for 24 h in hydroponics. PV accumulated 2919 mg/kg Cr in the roots at CrVI?.??, and 5100 and 3500 mg/kg P in the fronds and roots at P?.??. When co-present, CrVI and P inhibited each other's uptake in PV. Increasing P concentrations reduced Cr root concentrations by 62-82% whereas increasing CrVI concentrations reduced frond P concentrations by 52-59% but increased root P concentrations by 11-15%. Chromate reduced P transport, with more P being accumulated in PV roots. Though CrVI was supplied, 64-78% and 92-93% CrIII were in PV fronds and roots. Based on X-ray diffraction, Cr?O? was detected in the roots confirming CrVI reduction to CrIII by PV. In short, CrVI and P inhibited each other in uptake and translocation by PV, and CrVI reduction to CrIII in PV roots served as its detoxification mechanism. The finding helps to understand the interactions of P and Cr during their uptake in PV. PMID:25434865

  3. An arsenate-activated glutaredoxin from the arsenic hyperaccumulator fern Pteris vittata L. regulates intracellular arsenite.

    PubMed

    Sundaram, Sabarinath; Rathinasabapathi, Bala; Ma, Lena Q; Rosen, Barry P

    2008-03-01

    To elucidate the mechanisms of arsenic resistance in the arsenic hyperaccumulator fern Pteris vittata L., a cDNA for a glutaredoxin (Grx) Pv5-6 was isolated from a frond expression cDNA library based on the ability of the cDNA to increase arsenic resistance in Escherichia coli. The deduced amino acid sequence of Pv5-6 showed high homology with an Arabidopsis chloroplastic Grx and contained two CXXS putative catalytic motifs. Purified recombinant Pv5-6 exhibited glutaredoxin activity that was increased 1.6-fold by 10 mm arsenate. Site-specific mutation of Cys(67) to Ala(67) resulted in the loss of both GRX activity and arsenic resistance. PvGrx5 was expressed in E. coli mutants in which the arsenic resistance genes of the ars operon were deleted (strain AW3110), a deletion of the gene for the ArsC arsenate reductase (strain WC3110), and a strain in which the ars operon was deleted and the gene for the GlpF aquaglyceroporin was disrupted (strain OSBR1). Expression of PvGrx5 increased arsenic tolerance in strains AW3110 and WC3110, but not in OSBR1, suggesting that PvGrx5 had a role in cellular arsenic resistance independent of the ars operon genes but dependent on GlpF. AW3110 cells expressing PvGrx5 had significantly lower levels of arsenite when compared with vector controls when cultured in medium containing 2.5 mm arsenate. Our results are consistent with PvGrx5 having a role in regulating intracellular arsenite levels, by either directly or indirectly modulating the aquaglyceroporin. To our knowledge, PvGrx5 is the first plant Grx implicated in arsenic metabolism. PMID:18156657

  4. Characterization of a Selenium-Tolerant Rhizosphere Strain from a Novel Se-Hyperaccumulating Plant Cardamine hupingshanesis

    PubMed Central

    Yuan, Linxi; Luo, Lei; Yin, Xuebin

    2014-01-01

    A novel selenium- (Se-) hyperaccumulating plant, Cardamine hupingshanesis, accumulating Se as a form of SeCys2, was discovered in Enshi, Hubei, China, which could not be explained by present selenocysteine methyltransferase (SMT) theory. However, it is interesting to investigate if rhizosphere bacteria play some roles during SeCys2 accumulation. Here, one Se-tolerant rhizosphere strain, Microbacterium oxydans, was isolated from C. hupingshanesis. Phylogenetic analysis and 16S rRNA gene sequences determined the strain as a kind of Gram positive bacillus and belonged to the family Brevibacterium frigoritolerans. Furthermore, Se tolerance test indicated the strain could grow in extreme high Se level of 15.0?mg?Se?L?1. When exposed to 1.5?mg?Se L?1, SeCys2 was the predominant Se species in the bacteria, consistent with the Se species in C. hupingshanesis. This coincidence might reveal that this strain played some positive effect in SeCys2 accumulation of C. hupingshanesis. Moreover, when exposed to 1.5?mg Se?L?1 or 15.0?mg Se?L?1, As absorption diminished in the logarithmic phase. In contrast, As absorption increased when exposed to 7.5?mg Se?L?1, indicating As metabolism processes could be affected by Se on this strain. The present study provided a sight on the role of rhizosphere bacteria during Se accumulation for Se-hyperaccumulating plant. PMID:25478582

  5. Cadmium tolerance and accumulation of Althaea rosea Cav. and its potential as a hyperaccumulator under chemical enhancement.

    PubMed

    Liu, Jia Nv; Zhou, Qi Xing; Wang, Song; Sun, Ting

    2009-02-01

    The role of ornamental plants has drawn much attention as the urban pollution levels exacerbate. Althaea rosea Cav. had showed its strong tolerance and accumulation ability of Cd in our previous work, thus, the effects of ethylenediamine triacetic acid (EDTA), ethylenegluatarotriacetic acid (EGTA) and sodium dodecyl sulfate (SDS) on its Cd phytoremediation capacity were further investigated in this work. It reconfirmed that the species had strong tolerance and accumulation ability of Cd. Particularly, the species can be regarded as a potential Cd-hyperaccumulator through applying chemical agents. However, different chelators and surfactants had great differences in affecting hyperaccumulating characteristics of the species. EGTA and SDS could not only increase the dry biomass of the plants, but also promote Cd accumulation in shoots and roots. On the contrary, EDTA was toxic to the species by restraining the growth of plants, although it could promote Cd accumulation in shoots and roots of the plants to a certain extent. Thus, EGTA and SDS were effective in enhancing phytoremediation with Althaea rosea Cav. for Cd contaminated soils, while EDTA is ineffective in this regard. PMID:18259884

  6. Selenium biofortification of broccoli and carrots grown in soil amended with Se-enriched hyperaccumulator Stanleya pinnata.

    PubMed

    Bañuelos, Gary S; Arroyo, Irvin; Pickering, Ingrid J; Yang, Soo In; Freeman, John L

    2015-01-01

    Amending soils with Se-hyperaccumulator plant derived sources of selenium (Se) may be useful for increasing the Se content in food crops in Se-deficient regions of the world. In this study we evaluated total Se and the different chemical species of Se in broccoli and carrots grown in soils amended with ground shoots of the Se-hyperaccumulator Stanleyapinnata. With increasing application rates of S. pinnata, total plant Se concentrations increased to nutritionally ideal levels inside edible parts. Selenium compounds in aqueous extracts were analyzed by SAX-HPLC-ICPMS and identified as a variety of mainly organic-Se forms. Together with bulk Se K-edge X-ray absorption near-edge structure (XANES) analysis performed on broccoli florets, carrot roots and shoots, dried ground S. pinnata, and the amended soil at post-plant, we demonstrate that Se-enriched S. pinnata is valuable as a soil amendment for enriching broccoli and carrots with healthful forms of organic-Se. PMID:25053099

  7. Characterization of arsenate reductase in the extract of roots and fronds of Chinese brake fern, an arsenic hyperaccumulator.

    PubMed

    Duan, Gui-Lan; Zhu, Yong-Guan; Tong, Yi-Ping; Cai, Chao; Kneer, Ralf

    2005-05-01

    Root extracts from the arsenic (As) hyperaccumulating Chinese brake fern (Pteris vittata) were shown to be able to reduce arsenate to arsenite. An arsenate reductase (AR) in the fern showed a reaction mechanism similar to the previously reported Acr2p, an AR from yeast (Saccharomyces cerevisiae), using glutathione as the electron donor. Substrate specificity as well as sensitivity toward inhibitors for the fern AR (phosphate as a competitive inhibitor, arsenite as a noncompetitive inhibitor) was also similar to Acr2p. Kinetic analysis showed that the fern AR had a Michaelis constant value of 2.33 mM for arsenate, 15-fold lower than the purified Acr2p. The AR-specific activity of the fern roots treated with 2 mM arsenate for 9 d was at least 7 times higher than those of roots and shoots of plant species that are known not to tolerate arsenate. A T-DNA knockout mutant of Arabidopsis (Arabidopsis thaliana) with disruption in the putative Acr2 gene had no AR activity. We could not detect AR activity in shoots of the fern. These results indicate that (1) arsenite, the previously reported main storage form of As in the fern fronds, may come mainly from the reduction of arsenate in roots; and (2) AR plays an important role in the detoxification of As in the As hyperaccumulating fern. PMID:15834011

  8. Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii: the impact of citric acid and tartaric acid* #

    PubMed Central

    Lu, Ling-li; Tian, Sheng-ke; Yang, Xiao-e; Peng, Hong-yun; Li, Ting-qiang

    2013-01-01

    The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils. Organic acid has been suggested to be involved in toxic metallic element tolerance, translocation, and accumulation in plants. The impact of exogenous organic acids on cadmium (Cd) uptake and translocation in the zinc (Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study. By the addition of organic acids, short-term (2 h) root uptake of 109Cd increased significantly, and higher 109Cd contents in roots and shoots were noted 24 h after uptake, when compared to controls. About 85% of the 109Cd taken up was distributed to the shoots in plants with citric acid (CA) treatments, as compared with 75% within controls. No such effect was observed for tartaric acid (TA). Reduced growth under Cd stress was significantly alleviated by low CA. Long-term application of the two organic acids both resulted in elevated Cd in plants, but the effects varied with exposure time and levels. The results imply that CA may be involved in the processes of Cd uptake, translocation and tolerance in S. alfredii, whereas the impact of TA is mainly on the root uptake of Cd. PMID:23365009

  9. Elevated CO2 concentration increase the mobility of Cd and Zn in the rhizosphere of hyperaccumulator Sedum alfredii.

    PubMed

    Li, Tingqiang; Tao, Qi; Liang, Chengfeng; Yang, Xiaoe

    2014-05-01

    The effects of elevated CO2 on metal species and mobility in the rhizosphere of hyperaccumulator are not well understood. We report an experiment designed to compare the effects of elevated CO2 on Cd/Zn speciation and mobility in the rhizosphere of hyperaccumulating ecotype (HE) and a non-hyperaccumulating ecotype (NHE) of Sedum alfredii grown under ambient (350 ?l l(-1)) or elevated (800 ?l l(-1)) CO2 conditions. No difference in solution pH of NHE was observed between ambient and elevated CO2 treatments. For HE, however, elevated CO2 reduced soil solution pH by 0.22 unit, as compared to ambient CO2 conditions. Elevated CO2 increased dissolved organic carbon (DOC) and organic acid levels in soil solution of both ecotypes, but the increase in HE solution was much greater than in NHE solution. After the growth of HE, the concentrations of Cd and Zn in soil solution decreased significantly regardless of CO2 level. The visual MINTEQ speciation model predicted that Cd/Zn-DOM complexes were the dominant species in soil solutions, followed by free Cd(2+) and Zn(2+) species for both ecotypes. However, Cd/Zn-DOM complexes fraction in soil solution of HE was increased by the elevated CO2 treatment (by 8.01 % for Cd and 8.47 % for Zn, respectively). Resin equilibration experiment results indicated that DOM derived from the rhizosphere of HE under elevated CO2 (HE-DOM-E) (90 % for Cd and 73 % for Zn, respectively) showed greater ability to form complexes with Cd and Zn than those under ambient CO2 (HE-DOM-A) (82 % for Cd and 61 % for Zn, respectively) in the undiluted sample. HE-DOM-E showed greater ability to extract Cd and Zn from soil than HE-DOM-A. It was concluded that elevated CO2 could increase the mobility of Cd and Zn due to the enhanced formation of DOM-metal complexes in the rhizosphere of HE S. alfredii. PMID:24453019

  10. A proteomics approach to investigate the process of Zn hyperaccumulation in Noccaea caerulescens (J & C. Presl) F.K. Meyer.

    PubMed

    Schneider, Thomas; Persson, Daniel Pergament; Husted, Søren; Schellenberg, Maja; Gehrig, Peter; Lee, Youngsook; Martinoia, Enrico; Schjoerring, Jan K; Meyer, Stefan

    2012-09-13

    Zinc (Zn) is an essential trace element in all living organisms, but is toxic in excess. Several plant species are able to accumulate Zn at extraordinarily high concentrations in the leaf epidermis without showing any toxicity symptoms. However, the molecular mechanisms of this phenomenon are still poorly understood. A state-of-the-art quantitative 2D liquid chromatography/tandem mass spectrometry (2D-LC-MS/MS) proteomics approach was used to investigate the abundance of proteins involved in Zn hyperaccumulation in leaf epidermal and mesophyll tissues of Noccaea caerulescens. Furthermore, the Zn speciation in planta was analyzed by a size-exclusion chromatography/inductively coupled plasma mass spectrometer (SEC-ICP-MS) method, in order to identify the Zn-binding ligands and mechanisms responsible for Zn hyperaccumulation. Epidermal cells have an increased capability to cope with the oxidative stress that results from excess Zn, as indicated by a higher abundance of glutathione S-transferase proteins. A Zn importer of the ZIP family was more abundant in the epidermal tissue than in the mesophyll tissue, but the vacuolar Zn transporter MTP1 was equally distributed. Almost all of the Zn located in the mesophyll was stored as Zn-nicotianamine complexes. In contrast, a much lower proportion of the Zn was found as Zn-nicotianamine complexes in the epidermis. However, these cells have higher concentrations of malate and citrate, and these organic acids are probably responsible for complexation of most epidermal Zn. Here we provide evidence for a cell type-specific adaptation to excess Zn conditions and an increased ability to transport Zn into the epidermal vacuoles. PMID:22974502

  11. Intra-specific variation in Ni tolerance, accumulation and translocation patterns in the Ni-hyperaccumulator Alyssum lesbiacum.

    PubMed

    Adamidis, G C; Aloupi, M; Kazakou, E; Dimitrakopoulos, P G

    2014-01-01

    A hydroponic experiment was conducted to investigate inter-population variation in Ni tolerance, accumulation and translocation patterns in Alyssum lesbiacum. The in vitro results were compared to field data (soil bioavailable and leaf Ni concentrations) so as to examine any potential relationship between hydroponic and natural conditions. Seeds from the four major existing populations of A. lesbiacum were used for the cultivation of plantlets in solution cultures with incrementally increasing Ni concentrations (ranging from 0 to 250 ?mol L(-1) NiSO4). Ni accumulation and tolerance of shoots and roots, along with initial seed Ni concentration for each population were measured. The ratio of root or shoot length of plantlets grown in NiSO4 solutions to root or shoot lengths of plantlets grown in the control solution was used as tolerance index. For the range of metal concentrations used, A. lesbiacum presented significant inter-population variation in Ni tolerance, accumulation and translocation patterns. Initial seed Ni concentration was positively correlated to shoot Ni accumulation. A significant positive relationship between tolerance and accumulation was demonstrated. Initial seed Ni concentration along with physiological differences in xylem loading and Ni translocation of each population, appear to be the determining factors of the significant inter-population variation in Ni tolerance and accumulation. Our results highlight the inter-population variation in Ni tolerance and accumulation patterns in the Ni-hyperaccumulator A. lesbiacum and give support to the suggestion that the selection of metal hyperaccumulator species with enhanced phytoremediation efficiency should be considered at the population level. PMID:24182400

  12. Elucidating the selenium and arsenic metabolic pathways following exposure to the non-hyperaccumulating Chlorophytum comosum, spider plant

    PubMed Central

    Afton, Scott E.; Catron, Brittany; Caruso, Joseph A.

    2009-01-01

    Although many studies have investigated the metabolism of selenium and arsenic in hyperaccumulating plants for phytoremediation purposes, few have explored non-hyperaccumulating plants as a model for general contaminant exposure to plants. In addition, the result of simultaneous supplementation with selenium and arsenic has not been investigated in plants. In this study, Chlorophytum comosum, commonly known as the spider plant, was used to investigate the metabolism of selenium and arsenic after single and simultaneous supplementation. Size exclusion and ion-pairing reversed phase liquid chromatography were coupled to an inductively coupled plasma mass spectrometer to obtain putative metabolic information of the selenium and arsenic species in C. comosum after a mild aqueous extraction. The chromatographic results depict that selenium and arsenic species were sequestered in the roots and generally conserved upon translocation to the leaves. The data suggest that selenium was directly absorbed by C. comosum roots when supplemented with SeVI, but a combination of passive and direct absorption occurred when supplemented with SeIV due to the partial oxidation of SeIV to SeVI in the rhizosphere. Higher molecular weight selenium species were more prevalent in the roots of plants supplemented with SeIV, but in the leaves of plants supplemented with SeVI due to an increased translocation rate. When supplemented as AsIII, arsenic is proposed to be passively absorbed as AsIII and partially oxidized to AsV in the plant root. Although total elemental analysis demonstrates a selenium and arsenic antagonism, a compound containing selenium and arsenic was not present in the general aqueous extract of the plant. PMID:19273464

  13. Hyperaccumulator of Pb in native plants growing on Peruvian mine tailings

    NASA Astrophysics Data System (ADS)

    Bech, Jaume; Roca, Nuria; Boluda, Rafael; Tume, Pedro; Duran, Paola; Poma, Wilfredo; Sanchez, Isidoro

    2014-05-01

    Tailings usually provide an unfavourable substrate for plant growth because of their extreme pH, low organic matter and nutrients, high concentrations of trace elements and physical disturbance, such as bad soil structure, and low water availability. Heavy metal contamination has also been one serious problem in the vicinity of mine sites due to the discharge and dispersion of mine-waste materials into the ecosystem. Moreover, Pb is considered a target metal when undertaking soil remediation, because it is usually quite immobile and not readily accumulated in upper plant parts. The presence of vegetation reduces water and wind erosion, which may decrease the downward migration of contaminants into the groundwater and improve aesthetical aspects. Plants growing on naturally metal-enriched soils are of particular interest in this perspective, since they are genetically tolerant to high metal concentrations, have an excellent adaptation to this multi-stress environment. Efficient phytoextraction requires plant species combining both high metal tolerance and elevated capacity for metal uptake and metal translocation to easily harvestable plant organs (e.g. shoots). Soil and plant samples were taken in Peru, at a polymetallic mine (mainly Ag, Pb and Cu) in Cajamarca Province, Hualgayoc district. Top soils (0-20 cm) were analysed for physical and chemical properties by standard methods. Total Pb concentrations in top soils were determined by ICP-OES. Pb content in plants were analysed separately (aerial and root system) by ICP-MS. Ti content was used as an indicator for contamination of plant samples with soil particles. Translocation Factor (TF) and Shoot Accumulation Factor (SAF) were determined to assess the tolerance strategies developed by these species and to evaluate their potential for phytoremediation purposes. The non-polluted soils had near neutral pH (6.8±0.1), a great content of organic carbon (42 ± 4.0 g•kg-1) and a silt loamy texture. Soil and plant samples were taken at four locations (CA1, CA2, CA3, CA4) with different levels of Pb. The Pb soil content (mean ± standard deviation) in mg•kg-1 is as follows: CA1 3992 ± 301; CA2 10128 ± 2247, CA3 14197 ± 895, CA4 16060 ± 810. The non-polluted value around the mine was Pb 124 mg•kg-1. Unusual elevated concentrations of Pb (over 1000 mg kg-1) and TF greater than one were detected in shoots of 6 different plants species (Ageratina sp., Achirodine alata, Cortaderia apalothica, Epilobium denticulatum, Taraxacum officinalis and Trifolium repens). The location CA4 has the maximum content of Pb in the shoots of Ageratina sp. (5045±77 mg•kg-1), C. apalothica (3367±188 mg•kg-1), E. denticulatum (13599±848 mg•kg-1), T. officinalis (2533±47 mg•kg-1) and T. repens (2839±231 mg•kg-1). However, the BF (Bioaccumulation Factor) was smaller than one. Despite the low BF index, the great TFs for Pb indicate that these plant species effectively translocate this metal (i.e., 2.4 for Ageratina sp., 2.3 for C. apalothica, 1.6 for T. repens, 1.5 for A. alata, 1.3 for T. officinalis and 1.2 for E. denticulatum). It seems that the BF is not a reliable index when the metal soil concentration is extremely large. Controlled-environment studies must be performed to definitively confirm the Pb hyperaccumulation character of cited plant species.

  14. Accumulation of an organic anticancer selenium compound in a transgenic Solanaceous species shows wider applicability of the selenocysteine methyltransferase transgene from selenium hyperaccumulators

    Microsoft Academic Search

    Marian J. McKenzie; Donald A. Hunter; Ranjith Pathirana; Lyn M. Watson; Nigel I. Joyce; Adam J. Matich; Daryl D. Rowan; David A. Brummell

    2009-01-01

    Tolerance to high selenium (Se) soils in Se-hyperaccumulating plant species is correlated with the ability to biosynthesise\\u000a methylselenocysteine (MeSeCys), due to the activity of selenocysteine methyltransferase (SMT). In mammals, inclusion of MeSeCys\\u000a in the diet reduces the incidence of certain cancers, so increasing the range of crop plants that can produce this compound\\u000a is an attractive biotechnology target. However, in

  15. Characterization of Ni-resistant bacteria in the rhizosphere of the hyperaccumulator Alyssum murale by 16S rRNA gene sequence analysis

    Microsoft Academic Search

    R. A. I. Abou-Shanab; P. van Berkum; J. S. Angle; T. A. Delorme; R. L. Chaney; H. A. Ghozlan; K. Ghanem; H. Moawad

    2010-01-01

    The diversity of 184 isolates from rhizosphere and bulk soil samples taken from the Ni hyperaccumulator Alyssum murale, grown in a Ni-rich serpentine soil, was determined by 16S rRNA gene analysis. Restriction digestion of the 16S rRNA gene\\u000a was used to identify 44 groups. Representatives of each of these groups were placed within the phyla Proteobacteria, Firmicutes and Actinobacteria by

  16. A field-scale study of cadmium phytoremediation in a contaminated agricultural soil at Mae Sot District, Tak Province, Thailand: (1) Determination of Cd-hyperaccumulating plants.

    PubMed

    Khaokaew, Saengdao; Landrot, Gautier

    2014-11-01

    The cadmium (Cd) phytoremediation capabilities of Gynura pseudochina, Chromolaena odorata, Conyza sumatrensis, Crassocephalum crepidioides and Nicotiana tabacum were determined by conducting in-situ experiments in a highly Cd-contaminated agricultural field at Mae Sot District, Tak Province, Thailand. Most of these five plant species, which are commonly found in Thailand, previously demonstrated Cd-hyperaccumulating capacities under greenhouse conditions. This study represented an important initial step in determining if any of these plants could, under field-conditions, effectively remove Cd from the Mae Sot contaminated fields, which represent a health threat to thousands of local villagers. All plant species had at least a 95% survival rate on the final harvest day. Additionally, all plant species, except C. odorata, could hyperaccumulate the extractable Cd amounts present in the soil, based on their associated Bioaccumulation Factor (BAF), Translocation Factor (TF), and background Vegetation Factor (VF). Therefore, the four Cd-hyperaccumulating plant species identified in this study may successfully treat a majority of contaminated fields at Mae Sot, as it was previously reported that Cd amounts present in a number of these soils were mostly available. PMID:25454203

  17. The Hyperaccumulator Alyssum murale uses Complexation with Nitrogen and Oxygen Donor Ligands for Ni Transport and Storage

    SciTech Connect

    McNear, Jr., D.; Chanay, R; Sparks, D

    2010-01-01

    The Kotodesh genotype of the nickel (Ni) hyperaccumulator Alyssum murale was examined to determine the compartmentalization and internal speciation of Ni, and other elements, in an effort to ascertain the mechanism used by this plant to tolerate extremely high shoot (stem and leaf) Ni concentrations. Plants were grown either hydroponically or in Ni enriched soils from an area surrounding an historic Ni refinery in Port Colborne, Ontario, Canada. Electron probe micro-analysis (EPMA) and synchrotron based micro X-ray fluorescence ({mu}-SXRF) spectroscopy were used to determine the metal distribution and co-localization and synchrotron X-ray and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopies were used to determine the Ni speciation in plant parts and extracted sap. Nickel is concentrated in the dermal leaf and stem tissues of A. murale bound primarily to malate along with other low molecular weight organic ligands and possibly counter anions (e.g., sulfate). Ni is present in the plant sap and vasculature bound to histidine, malate and other low molecular weight compounds. The data presented herein supports a model in which Ni is transported from the roots to the shoots complexed with histidine and stored within the plant leaf dermal tissues complexed with malate, and other low molecular weight organic acids or counter-ions.

  18. Impaired leaf CO2 diffusion mediates Cd-induced inhibition of photosynthesis in the Zn/Cd hyperaccumulator Picris divaricata.

    PubMed

    Tang, Lu; Ying, Rong-Rong; Jiang, Dan; Zeng, Xiao-Wen; Morel, Jean-Louis; Tang, Ye-Tao; Qiu, Rong-Liang

    2013-12-01

    Mechanisms of cadmium (Cd)-induced inhibition of photosynthesis in the Zn/Cd hyperaccumulator Picris divaricata were investigated using photosynthesis limitation analysis. P. divaricata seedlings were grown in nutrient solution containing 0, 5, 10, 25, 50, or 75 ?M Cd for 2 weeks. Total limitations to photosynthesis (TL) increased from 0% at 5 ?M Cd to 68.8% at 75 ?M Cd. CO2 diffusional limitation (DL) made the largest contribution to TL, accounting for 93-98% of TL in the three highest Cd treatments, compared to just 2-7% of TL attributable to biochemical limitation (BL). Microscopic imaging revealed significantly decreased stomatal density and mesophyll thickness in the three highest Cd treatments. Chlorophyll fluorescence parameters related to photosynthetic biochemistry (Fv/Fm, NPQ, ?PSII, and qP) were not significantly decreased by increased Cd supply. Our results suggest that increased DL in leaves is the main cause of Cd-induced inhibition of photosynthesis in P. divaricata, possibly due to suppressed function of mesophyll and stomata. Analysis of chlorophyll fluorescence showed that Cd supply had little effect on photochemistry parameters, suggesting that the PSII reaction centers are not a main target of Cd inhibition of photosynthesis in P. divaricata. PMID:24077231

  19. Effects of arsenate, chromate, and sulfate on arsenic and chromium uptake and translocation by arsenic hyperaccumulator Pteris vittata L.

    PubMed

    de Oliveira, Letúzia Maria; Ma, Lena Q; Santos, Jorge A G; Guilherme, Luiz R G; Lessl, Jason T

    2014-01-01

    We investigated effects of arsenate (AsV), chromate (CrVI) and sulfate on As and Cr uptake and translocation by arsenic hyperaccumulator Pteris vittata (PV), which was exposed to AsV, CrVI and sulfate at 0, 0.05, 0.25 or 1.25 mM for 2-wk in hydroponic system. PV was effective in accumulating large amounts of As (4598 and 1160 mg/kg in the fronds and roots at 0.05 mM AsV) and Cr (234 and 12,630 mg/kg in the fronds and roots at 0.05 mM CrVI). However, when co-present, AsV and CrVI acted as inhibitors, negatively impacting their accumulation in PV. Arsenic accumulation in the fronds was reduced by 92% and Cr by 26%, indicating reduced As and Cr translocation. However, addition of sulfate increased uptake and translocation of As by 26-28% and Cr by 1.63 fold. This experiment demonstrated that As and Cr inhibited each other in uptake and translocation by PV but sulfate enhanced As and Cr uptake and translocation by PV. PMID:24056188

  20. Selection and validation of reference genes for real-time quantitative PCR in hyperaccumulating ecotype of Sedum alfredii under different heavy metals stresses.

    PubMed

    Sang, Jian; Han, Xiaojiao; Liu, Mingying; Qiao, Guirong; Jiang, Jing; Zhuo, Renying

    2013-01-01

    Real-time Quantitative PCR (RT-qPCR) has become an effective method for accurate analysis of gene expression in several biological systems as well as under different experimental conditions. Although with high sensitivity, specificity and broad dynamic range, this method requires suitable reference genes for transcript normalization in order to guarantee reproducible and meaningful results. In the present study, we evaluated five traditional housekeeping genes and five novel reference genes in Hyperaccumulating ecotype of Sedum alfredii, a well known hyperaccumulator for heavy metals phytoremediation, under Cd, Pb, Zn and Cu stresses of seven different durations. The expression stability of these ten candidates were determined with three programs--geNorm, NormFinder and BestKeeper. The results showed that all the selected reference genes except for SAND could be used for RT-qPCR normalization. Among them UBC9 and TUB were ranked as the most stable candidates across all samples by three programs together. For the least stable reference genes, however, BestKeeper produced different results compared with geNorm and NormFinder. Meanwhile, the expression profiles of PCS under Cd, Pb, Zn and Cu stresses were assessed using UBC9 and TUB respectively, and similar trends were obtained from the results of the two groups. The distinct expression patterns of PCS indicated that various strategies could be taken by plants in adaption to different heavy metals stresses. This study will provide appropriate reference genes for further gene expression quantification using RT-qPCR in Hyperaccumulator S. alfredii. PMID:24340067

  1. Elevated salicylic acid levels conferred by increased expression of ISOCHORISMATE SYNTHASE 1 contribute to hyperaccumulation of SUMO1 conjugates in the Arabidopsis mutant early in short days 4.

    PubMed

    Villajuana-Bonequi, Mitzi; Elrouby, Nabil; Nordström, Karl; Griebel, Thomas; Bachmair, Andreas; Coupland, George

    2014-07-01

    Post-translational modification of proteins by attachment of small ubiquitin-like modifier (SUMO) is essential for plant growth and development. Mutations in the SUMO protease early in short days 4 (ESD4) cause hyperaccumulation of conjugates formed between SUMO and its substrates, and phenotypically are associated with extreme early flowering and impaired growth. We performed a suppressor mutagenesis screen of esd4 and identified a series of mutants called suppressor of esd4 (sed), which delay flowering, enhance growth and reduce hyperaccumulation of SUMO conjugates. Genetic mapping and genome sequencing indicated that one of these mutations (sed111) is in the gene salicylic acid induction-deficient 2 (SID2), which encodes ISOCHORISMATE SYNTHASE I, an enzyme required for biosynthesis of salicylic acid (SA). Analyses showed that compared with wild-type plants, esd4 contains higher levels of SID2 mRNA and about threefold more SA, whereas sed111 contains lower SA levels. Other sed mutants also contain lower SA levels but are not mutant for SID2, although most reduce SID2 mRNA levels. Therefore, higher SA levels contribute to the small size, early flowering and elevated SUMO conjugate levels of esd4. Our results support previous data indicating that SUMO homeostasis influences SA biosynthesis in wild-type plants, and also demonstrate that elevated levels of SA strongly increase the abundance of SUMO conjugates. PMID:24816345

  2. Increased ecological risk due to the hyperaccumulation of As in Pteris cretica during the phytoremediation of an As-contaminated site.

    PubMed

    Jeong, Seulki; Moon, Hee Sun; Nam, Kyoungphile

    2015-03-01

    Ecological risk due to the hyperaccumulation of As in Pteris cretica during phytoremediation was evaluated at an abandoned As-contaminated site. Five receptor groups representing terrestrial invertebrates, avian insectivores, small mammals, herbivores, and omnivores were selected as potentially affected ecological receptors. Soil and food ingestion were considered as major exposure pathways. Phytoremediation was performed with P.cretica only and with both P.cretica and siderophores to enhance plant uptake of As. Ecological hazard index (EHI) values for the small mammal greatly exceeded 1.0 even after three weeks of growth regardless of siderophore application, probably due to its limited home range. For the mammalian herbivore, which mainly consumes plant foliage, the EHI values were greater than 5.73 after seven weeks without siderophore application, but the value increased sharply to 29.3 at seven weeks when siderophores were applied. This increased risk could be attributed to the facilitated translocation of As from roots to stems and leaves in P.cretica. Our results suggest that, when a phytoremediation strategy is considered for metals remediation, its ecological consequences should be taken into account to prevent the spread of hyperaccumulated heavy metals throughout the food chain of ecological receptors. Uncertainties involved in the ecological risk assessment process were also discussed. PMID:25441929

  3. Effective selenium detoxification in the seed proteins of a hyperaccumulator plant: the analysis of selenium-containing proteins of monkeypot nut (Lecythis minor) seeds.

    PubMed

    Németh, Anikó; Dernovics, Mihály

    2015-01-01

    A shotgun proteomic approach was applied to characterize the selenium (Se)-containing proteins of the selenium hyperaccumulator monkeypot nut (Lecythis minor) seeds. The exceptionally high Se content (>4,000 mg kg(-1)) of the sample enabled a straightforward procedure without the need for multiple preconcentration and fractionation steps. The proteins identified were sulfur-rich seed proteins, namely, 11S globulin (Q84ND2), 2S albumin (B6EU54), 2S sulfur-rich seed storage proteins (P04403 and P0C8Y8) and a 11S globulin-like protein (A0EM48). Database directed search for theoretically selenium-containing peptides was assisted by manual spectra evaluation to achieve around 25% coverage on sulfur analogues. Remarkable detoxification mechanisms on the proteome level were revealed in the form of multiple selenomethionine-methionine substitution and the lack of selenocysteine residues. The degree of selenomethionine substitution could be characterized by an exponential function that implies the inhibition of protein elongation by selenomethionine. Our results contribute to the deeper understanding of selenium detoxification procedures in hyperaccumulator plants. PMID:25373701

  4. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1997--June 19, 1997

    SciTech Connect

    Kochian, L.

    1997-11-01

    This laboratory has been involved in a collaborative project focusing on a range of issues related to the phytoremediation of heavy metal-and radionuclide- contaminated soils. While much of the research has been fundamental in nature, involving physiological and molecular characterizations of the mechanisms of hyperaccumulation in plants, the laboratory is also investigating more practical issues related to phytoremediation. A central issue in this latter research has been the identification of amendments capable of increasing the bioavailability and subsequent phytoextraction of radionuclides. The results described here detail these efforts for uranium and Cs-137. A study was also conducted on a Cs-137 contaminated site at Brookhaven National Laboratory (BNL), which allowed application of the laboratory and greenhouse results to a field setting.

  5. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species, Quarterly technical progress report, December 20, 1995--March 20, 1995

    SciTech Connect

    Kochian, L.; Brady, D.; Last, M.; Ebbs, S.

    1995-12-01

    Although the period covered by this progress report began on December 20, 1994, which was the date that DOE approved the Interagency Agreement, the agreement was not approved by USDA until January 9, 1995 and the first scientists working on the project were not hired until February 1, 1995. The first goal of the research supported by the Interagency Agreement is to use hydroponic techniques to identify plant species and genotypes with potential for heavy metal hyperaccumulation for planting on a test site at Silverbow Creek and for radionuclide ({sup 90}Sr and {sup 137}Cs) accumulation on a test site at INEL, Idaho, later this year. The second goal of this research is to identify soil amendment procedures that will enhance the bioavailability of heavy metals and radionuclides in the soil without increasing the movement of the contaminants of concern (COC`s) into the groundwater. Our initial research covered in this report focuses on the first goal.

  6. "Towards practical cadmium phytoextraction with Thlaspi caerulescens"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During 2005-2007, a series of field trials were conducted to investigate the potential of Thlapsi caerulescens ecotypes derived from southern France to phytoextract localized Cd/Zn contamination in Thailand. Soil treatments included pH variation and fertilization level. T. caerulescens ecotypes w...

  7. Arsenic hyperaccumulation by Pteris vittata and Pityrogramma calomelanos: a comparative study of uptake efficiency in arsenic-treated soils and waters.

    PubMed

    Yong, J W H; Tan, S N; Ng, Y F; Low, K K K; Peh, S F; Chua, J C; Lim, A A B

    2010-01-01

    This work comprised of the comparative study of arsenic (As) uptake efficiency by Pteris vittata and Pityrogramma calomelanos grown in (i) As amended soils (0-600 ppm) and (ii) As tainted water (40 ppb) using a new compact continuous flow phytofiltration system in a tropical greenhouse. The As hyperaccumulation efficiency was dependent on the growth medium for the two fern species. The highest level of As detected in the fronds of P. vittata was 19,300+/-190 ppm (dry weight basis) and 11,600+/-230 ppm for Pityrogramma calomelanos, after growing for 78 days in soils amended with As. In the compact continuous flow As phytofiltration system experiments, Pityrogramma calomelanos was found to perform better than P. vittata in phytofiltrating As contaminated water under waterlogged conditions. During the 167 h of phytofiltration experiment, the removal efficiency was approximately 99% and 67% for Pityrogramma calomelanos and P. vittata systems respectively, based on an initial 40 ppb As. Pityrogramma calomelanos also required a shorter acclimatization time than P. vittata under waterlogged conditions. PMID:20555200

  8. A Vacuolar Arsenite Transporter Necessary for Arsenic Tolerance in the Arsenic Hyperaccumulating Fern Pteris vittata Is Missing in Flowering Plants[W][OA

    PubMed Central

    Indriolo, Emily; Na, GunNam; Ellis, Danielle; Salt, David E.; Banks, Jo Ann

    2010-01-01

    The fern Pteris vittata tolerates and hyperaccumulates exceptionally high levels of the toxic metalloid arsenic, and this trait appears unique to the Pteridaceae. Once taken up by the root, arsenate is reduced to arsenite as it is transported to the lamina of the frond, where it is stored in cells as free arsenite. Here, we describe the isolation and characterization of two P. vittata genes, ACR3 and ACR3;1, which encode proteins similar to the ACR3 arsenite effluxer of yeast. Pv ACR3 is able to rescue the arsenic-sensitive phenotypes of yeast deficient for ACR3. ACR3 transcripts are upregulated by arsenic in sporophyte roots and gametophytes, tissues that directly contact soil, whereas ACR3;1 expression is unaffected by arsenic. Knocking down the expression of ACR3, but not ACR3;1, in the gametophyte results in an arsenite-sensitive phenotype, indicating that ACR3 plays a necessary role in arsenic tolerance in the gametophyte. We show that ACR3 localizes to the vacuolar membrane in gametophytes, indicating that it likely effluxes arsenite into the vacuole for sequestration. Whereas single-copy ACR3 genes are present in moss, lycophytes, other ferns, and gymnosperms, none are present in angiosperms. The duplication of ACR3 in P. vittata and the loss of ACR3 in angiosperms may explain arsenic tolerance in this unusual group of ferns while precluding the same trait in angiosperms. PMID:20530755

  9. Microbial communities and functional genes associated with soil arsenic contamination and the rhizosphere of the arsenic-hyperaccumulating plant Pteris vittata L.

    PubMed

    Xiong, Jinbo; Wu, Liyou; Tu, Shuxin; Van Nostrand, Joy D; He, Zhili; Zhou, Jizhong; Wang, Gejiao

    2010-11-01

    To understand how microbial communities and functional genes respond to arsenic contamination in the rhizosphere of Pteris vittata, five soil samples with different arsenic contamination levels were collected from the rhizosphere of P. vittata and nonrhizosphere areas and investigated by Biolog, geochemical, and functional gene microarray (GeoChip 3.0) analyses. Biolog analysis revealed that the uncontaminated soil harbored the greatest diversity of sole-carbon utilization abilities and that arsenic contamination decreased the metabolic diversity, while rhizosphere soils had higher metabolic diversities than did the nonrhizosphere soils. GeoChip 3.0 analysis showed low proportions of overlapping genes across the five soil samples (16.52% to 45.75%). The uncontaminated soil had a higher heterogeneity and more unique genes (48.09%) than did the arsenic-contaminated soils. Arsenic resistance, sulfur reduction, phosphorus utilization, and denitrification genes were remarkably distinct between P. vittata rhizosphere and nonrhizosphere soils, which provides evidence for a strong linkage among the level of arsenic contamination, the rhizosphere, and the functional gene distribution. Canonical correspondence analysis (CCA) revealed that arsenic is the main driver in reducing the soil functional gene diversity; however, organic matter and phosphorus also have significant effects on the soil microbial community structure. The results implied that rhizobacteria play an important role during soil arsenic uptake and hyperaccumulation processes of P. vittata. PMID:20833780

  10. Micropropagation of Myriophyllum alterniflorum (Haloragaceae) for stream rehabilitation: first in vitro culture and reintroduction assays of a heavy-metal hyperaccumulator immersed macrophyte.

    PubMed

    Delmail, David; Labrousse, Pascal; Hourdin, Philippe; Larcher, Laure; Moesch, Christian; Botineau, Michel

    2013-01-01

    Nowadays, submersed aquatic macrophytes play a key role in stream ecology and they are often used as biomonitors of freshwater quality. So, these plants appear as natural candidates to stream rehabilitation experiments. Among them, the stream macrophyte Myriophyllum alterniflorum is used recently as biomonitor and is potentially useful for the restoration of heavy-metal contaminated localities. The best way to obtain a mass production of watermilfoil plants is micropropagation. We developed in vitro culture of M. alterniflorum and the effects of five media on the plant development were assessed. Five morphological and four physiological endpoints were examined leading to the recommendation of the Murashige and Skoog medium for ecotoxicological studies on chlorophyllous parts, and of the Gaudet medium for root cytotoxicity and phytoremediation studies. Micropropagated clones were acclimatized in a synthetic medium and in situ reintroduction was performed efficiently. This is the first report of micropropagated plants transplantation in streams. The successful establishment of watermilfoil beds even in polluted areas strongly suggested that ecological restoration using micropropagated watermilfoil is a promising biotechnology for phytoremediation and rehabilitation of degraded areas. Moreover, high bioconcentration factors evidenced that watermilfoil hyperaccumulates Cd and Cu, and could be potentially used in phytoremediation studies. PMID:23819265

  11. Contrasting effects of nicotianamine synthase knockdown on zinc and nickel tolerance and accumulation in the zinc/cadmium hyperaccumulator Arabidopsis halleri.

    PubMed

    Cornu, Jean-Yves; Deinlein, Ulrich; Höreth, Stephan; Braun, Manuel; Schmidt, Holger; Weber, Michael; Persson, Daniel P; Husted, Søren; Schjoerring, Jan K; Clemens, Stephan

    2015-04-01

    Elevated nicotianamine synthesis in roots of Arabidopsis halleri has been established as a zinc (Zn) hyperaccumulation factor. The main objective of this study was to elucidate the mechanism of nicotianamine-dependent root-to-shoot translocation of metals. Metal tolerance and accumulation in wild-type (WT) and AhNAS2-RNA interference (RNAi) plants were analysed. Xylem exudates were subjected to speciation analysis and metabolite profiling. Suppression of root nicotianamine synthesis had no effect on Zn and cadmium (Cd) tolerance but rendered plants nickel (Ni)-hypersensitive. It also led to a reduction of Zn root-to-shoot translocation, yet had the opposite effect on Ni mobility, even though both metals form coordination complexes of similar stability with nicotianamine. Xylem Zn concentrations were positively, yet nonstoichiometrically, correlated with nicotianamine concentrations. Two fractions containing Zn coordination complexes were detected in WT xylem. One of them was strongly reduced in AhNAS2-suppressed plants and coeluted with (67) Zn-labelled organic acid complexes. Organic acid concentrations were not responsive to nicotianamine concentrations and sufficiently high to account for complexing the coordinated Zn. We propose a key role for nicotianamine in controlling the efficiency of Zn xylem loading and thereby the formation of Zn coordination complexes with organic acids, which are the main Zn ligands in the xylem but are not rate-limiting for Zn translocation. PMID:25545296

  12. Microbial Communities and Functional Genes Associated with Soil Arsenic Contamination and the Rhizosphere of the Arsenic-Hyperaccumulating Plant Pteris vittata L. ? †

    PubMed Central

    Xiong, Jinbo; Wu, Liyou; Tu, Shuxin; Van Nostrand, Joy D.; He, Zhili; Zhou, Jizhong; Wang, Gejiao

    2010-01-01

    To understand how microbial communities and functional genes respond to arsenic contamination in the rhizosphere of Pteris vittata, five soil samples with different arsenic contamination levels were collected from the rhizosphere of P. vittata and nonrhizosphere areas and investigated by Biolog, geochemical, and functional gene microarray (GeoChip 3.0) analyses. Biolog analysis revealed that the uncontaminated soil harbored the greatest diversity of sole-carbon utilization abilities and that arsenic contamination decreased the metabolic diversity, while rhizosphere soils had higher metabolic diversities than did the nonrhizosphere soils. GeoChip 3.0 analysis showed low proportions of overlapping genes across the five soil samples (16.52% to 45.75%). The uncontaminated soil had a higher heterogeneity and more unique genes (48.09%) than did the arsenic-contaminated soils. Arsenic resistance, sulfur reduction, phosphorus utilization, and denitrification genes were remarkably distinct between P. vittata rhizosphere and nonrhizosphere soils, which provides evidence for a strong linkage among the level of arsenic contamination, the rhizosphere, and the functional gene distribution. Canonical correspondence analysis (CCA) revealed that arsenic is the main driver in reducing the soil functional gene diversity; however, organic matter and phosphorus also have significant effects on the soil microbial community structure. The results implied that rhizobacteria play an important role during soil arsenic uptake and hyperaccumulation processes of P. vittata. PMID:20833780

  13. Cadmium Sorption Characteristics of Soil Amendments and its Relationship with the Cadmium Uptake by Hyperaccumulator and Normal Plants in Amended Soils

    PubMed Central

    Sun, Yan; Wu, Qi-Tang; Lee, Charles C.C.; Li, Baoqin; Long, Xinxian

    2013-01-01

    In order to select appropriate amendments for cropping hyperaccumulator or normal plants on contaminated soils and establish the relationship between Cd sorption characteristics of soil amendments and their capacity to reduce Cd uptake by plants, batch sorption experiments with 11 different clay minerals and organic materials and a pot experiment with the same amendments were carried out. The pot experiment was conducted with Sedum alfredii and maize (Zea mays) in a co-cropping system. The results showed that the highest sorption amount was by montmorillonite at 40.82 mg/g, while mica was the lowest at only 1.83 mg/g. There was a significant negative correlation between the n value of Freundlich equation and Cd uptake by plants, and between the logarithm of the stability constant K of the Langmuir equation and plant uptake. Humic acids (HAs) and mushroom manure increased Cd uptake by S. alfredii, but not maize, thus they are suitable as soil amendments for the co-cropping S. alfredii and maize. The stability constant K in these cases was 0.14–0.16 L/mg and n values were 1.51–2.19. The alkaline zeolite and mica had the best fixation abilities and significantly decreased Cd uptake by the both plants, with K ? 1.49 L/mg and n ? 3.59. PMID:24912231

  14. Characterization of lead resistant endophytic Bacillus sp. MN3-4 and its potential for promoting lead accumulation in metal hyperaccumulator Alnus firma.

    PubMed

    Shin, Mi-Na; Shim, Jaehong; You, Youngnam; Myung, Hyun; Bang, Keuk-Soo; Cho, Min; Kamala-Kannan, Seralathan; Oh, Byung-Taek

    2012-01-15

    The aim of this study was to isolate and characterize endophytic bacteria from the roots of the metal hyperaccumulator plant Alnus firma. A total of 14 bacterial endophytes were isolated from root samples and assayed for tolerance to heavy metals. Isolate MN3-4 exhibited maximum bioremoval of Pb and was subsequently identified as Bacillus sp. based on 16S rRNA sequences. The pH and initial metal concentration highly influenced the Pb bioremoval rate. The growth of isolate MN3-4 was moderately altered in the presence of metals. Scanning electron microscopy, energy dispersive spectroscopy, biological-transmission electron microscopy, and Fourier transform infrared spectroscopy studies revealed that isolate MN3-4 had extracellularly sequestered the Pb molecules with little intracellular accumulation. Isolate MN3-4 did not harbor pbrA and pbrT genes. Moreover, isolate MN3-4 had the capacity to produce siderophores and indoleacetic acid. A root elongation assay demonstrated an increase (46.25%) in the root elongation of inoculated Brassica napus seedlings compared to that of the control plants. Obtained results pointed out that isolate MN3-4 could potentially reduce heavy metal phytotoxicity and increase Pb accumulation in A. firma plants. PMID:22133352

  15. Aluminium Uptake and Translocation in Al Hyperaccumulator Rumex obtusifolius Is Affected by Low-Molecular-Weight Organic Acids Content and Soil pH

    PubMed Central

    Vondrá?ková, Stanislava; Száková, Ji?ina; Drábek, Ond?ej; Tejnecký, Václav; Hejcman, Michal; Müllerová, Vladimíra; Tlustoš, Pavel

    2015-01-01

    Background and Aims High Al resistance of Rumex obtusifolius together with its ability to accumulate Al has never been studied in weakly acidic conditions (pH > 5.8) and is not sufficiently described in real soil conditions. The potential elucidation of the role of organic acids in plant can explain the Al tolerance mechanism. Methods We established a pot experiment with R. obtusifolius planted in slightly acidic and alkaline soils. For the manipulation of Al availability, both soils were untreated and treated by lime and superphosphate. We determined mobile Al concentrations in soils and concentrations of Al and organic acids in organs. Results Al availability correlated positively to the extraction of organic acids (citric acid < oxalic acid) in soils. Monovalent Al cations were the most abundant mobile Al forms with positive charge in soils. Liming and superphosphate application were ambiguous measures for changing Al mobility in soils. Elevated transport of total Al from belowground organs into leaves was recorded in both lime-treated soils and in superphosphate-treated alkaline soil as a result of sufficient amount of Ca available from soil solution as well as from superphosphate that can probably modify distribution of total Al in R. obtusifolius as a representative of “oxalate plants.” The highest concentrations of Al and organic acids were recorded in the leaves, followed by the stem and belowground organ infusions. Conclusions In alkaline soil, R. obtusifolius is an Al-hyperaccumulator with the highest concentrations of oxalate in leaves, of malate in stems, and of citrate in belowground organs. These organic acids form strong complexes with Al that can play a key role in internal Al tolerance but the used methods did not allow us to distinguish the proportion of total Al-organic complexes to the free organic acids. PMID:25880431

  16. Improved plant growth and Zn accumulation in grains of rice (Oryza sativa L.) by inoculation of endophytic microbes isolated from a Zn Hyperaccumulator, Sedum alfredii H.

    PubMed

    Wang, Yuyan; Yang, Xiaoe; Zhang, Xincheng; Dong, Lanxue; Zhang, Jie; Wei, Yanyan; Feng, Ying; Lu, Lingli

    2014-02-26

    This study is to investigate the possibility of zinc (Zn) biofortification in the grains of rice (Oryza sativa L.) by inoculation of endophytic strains isolated from a Zn hyperaccumulator, Sedum alfredii Hance. Five endophytic strains, Burkholderia sp. SaZR4, Burkholderia sp. SaMR10, Sphingomonas sp. SaMR12, Variovorax sp. SaNR1, and Enterobacter sp. SaCS20, isolated from S. alfredii, were inoculated in the roots of Japonica rice Nipponbare under hydroponic condition. Fluorescence images showed that endophytic strains successfully colonized rice roots after 72 h. Improved root morphology and plant growth of rice was observed after inoculation with endophytic strains especially SaMR12 and SaCS20. Under hydroponic conditions, endophytic inoculation with SaMR12 and SaCS20 increased Zn concentration by 44.4% and 51.1% in shoots, and by 73.6% and 83.4% in roots, respectively. Under soil conditions, endophytic inoculation with SaMR12 and SaCS20 resulted in an increase of grain yields and elevated Zn concentrations by 20.3% and 21.9% in brown rice and by 13.7% and 11.2% in polished rice, respectively. After inoculation of SaMR12 and SaCS20, rhizosphere soils of rice plants contained higher concentration of DTPA-Zn by 10.4% and 20.6%, respectively. In situ micro-X-ray fluorescence mapping of Zn confirmed the elevated Zn content in the rhizosphere zone of rice treated with SaMR12 as compared with the control. The above results suggested that endophytic microbes isolated from S. alfredii could successfully colonize rice roots, resulting in improved root morphology and plant growth, increased Zn bioavailability in rhizosphere soils, and elevated grain yields and Zn densities in grains. PMID:24447030

  17. Effect of copper stress on cup lichens Cladonia humilis and C. subconistea growing on copper-hyperaccumulating moss Scopelophila cataractae at copper-polluted sites in Japan.

    PubMed

    Nakajima, Hiromitsu; Fujimoto, Kenjiro; Yoshitani, Azusa; Yamamoto, Yoshikazu; Sakurai, Haruka; Itoh, Kiminori

    2012-10-01

    We investigated lichen species in the habitats of the copper (Cu)-hyperaccumulating moss Scopelophila cataractae and found that the cup lichens Cladonia subconistea and C. humilis grow on this moss. We performed X-ray fluorescence and inductively coupled plasma mass (ICP-MS) analysis of lichen samples and measured the visible absorption spectra of the pigments extracted from the samples to assess the effect of Cu stress on the cup lichens. The chlorophyll a/b ratio and degradation of chlorophyll a to pheophytin a were calculated from the spectral data. X-ray fluorescence analysis indicated that Cu concentrations in cup lichens growing on S. cataractae were much higher than those in control samples growing on non-polluted soil. Moreover, Cu microanalysis showed that Cu concentrations in parts of podetia of C. subconistea growing on S. cataractae increased as the substrate (S. cataractae) was approached, whereas those of C. humilis growing on S. cataractae decreased as the substrate was approached. This reflects the difference in the route of Cu ions from the source to the podetia. Furthermore, ICP-MS analysis confirmed that C. subconistea growing on S. cataractae was heavily contaminated with Cu, indicating that this lichen is Cu tolerant. We found a significant difference between the visible absorption spectra of pigments extracted from the Cu-contaminated and control samples. Hence, the spectra could be used to determine whether a cup lichen is contaminated with Cu. Chlorophyll analysis showed that cup lichens growing on S. cataractae were affected by Cu stress. However, it also suggested that the areas of dead moss under cup lichens were a suitable substrate for the growth of the lichen. Moreover, it suggested that cup lichens had allolepathic effects on S. cataractae; it is likely that secondary metabolites produced by cup lichens inhibited moss growth. PMID:22906716

  18. Elemental selenium particles at nano-size (Nano-Se) are more toxic to Medaka (Oryzias latipes) as a consequence of hyper-accumulation of selenium: a comparison with sodium selenite.

    PubMed

    Li, Hongcheng; Zhang, Jinsong; Wang, Thanh; Luo, Wenru; Zhou, Qunfang; Jiang, Guibin

    2008-09-29

    Recent studies have shown that elemental selenium particles at nano-size (Nano-Se) exhibited comparable bioavailability and less toxicity in mice and rats when compared to sodium selenite, selenomethinine and methylselenocysteine. However, little is known about the toxicity profile of Nano-Se in aquatic animals. In the present study, toxicities of Nano-Se and selenite in selenium-sufficient Medaka fish were compared. Selenium bioaccumulation and subsequent clearance in fish livers, gills, muscles and whole bodies were examined after 10 days of exposure to Nano-Se and selenite (100 microg Se/L) and again after 7 days of depuration. Both forms of selenium exposure effectively increased selenium concentrations in the investigated tissues. Surprisingly, Nano-Se was found to be more hyper-accumulated in the liver compared to selenite with differences as high as sixfold. Selenium clearance of both Nano-Se and selenite occurred at similar ratios in whole bodies and muscles but was not rapidly cleared from livers and gills. Nano-Se exhibited strong toxicity for Medaka with an approximately fivefold difference in terms of LC(50) compared to selenite. Nano-Se also caused larger effects on oxidative stress, most likely due to more hyper-accumulation of selenium in liver. The present study suggests that toxicity of nanoparticles can largely vary between different species and concludes that the evaluation of nanotoxicology should be carried out on a case-by-case basis. PMID:18768225

  19. Identification of Target Genes of the bZIP Transcription Factor OsTGAP1, Whose Overexpression Causes Elicitor-Induced Hyperaccumulation of Diterpenoid Phytoalexins in Rice Cells

    PubMed Central

    Miyamoto, Koji; Matsumoto, Takashi; Okada, Atsushi; Komiyama, Kohei; Chujo, Tetsuya; Yoshikawa, Hirofumi; Nojiri, Hideaki; Yamane, Hisakazu; Okada, Kazunori

    2014-01-01

    Phytoalexins are specialised antimicrobial metabolites that are produced by plants in response to pathogen attack. Momilactones and phytocassanes are the major diterpenoid phytoalexins in rice and are synthesised from geranylgeranyl diphosphate, which is derived from the methylerythritol phosphate (MEP) pathway. The hyperaccumulation of momilactones and phytocassanes due to the hyperinductive expression of the relevant biosynthetic genes and the MEP pathway gene OsDXS3 in OsTGAP1-overexpressing (OsTGAP1ox) rice cells has previously been shown to be stimulated by the chitin oligosaccharide elicitor. In this study, to clarify the mechanisms of the elicitor-stimulated coordinated hyperinduction of these phytoalexin biosynthetic genes in OsTGAP1ox cells, transcriptome analysis and chromatin immunoprecipitation with next-generation sequencing were performed, resulting in the identification of 122 OsTGAP1 target genes. Transcriptome analysis revealed that nearly all of the momilactone and phytocassane biosynthetic genes, which are clustered on chromosomes 4 and 2, respectively, and the MEP pathway genes were hyperinductively expressed in the elicitor-stimulated OsTGAP1ox cells. Unexpectedly, none of the clustered genes was included among the OsTGAP1 target genes, suggesting that OsTGAP1 did not directly regulate the expression of these biosynthetic genes through binding to each promoter region. Interestingly, however, several OsTGAP1-binding regions were found in the intergenic regions among and near the cluster regions. Concerning the MEP pathway genes, only OsDXS3, which encodes a key enzyme of the MEP pathway, possessed an OsTGAP1-binding region in its upstream region. A subsequent transactivation assay further confirmed the direct regulation of OsDXS3 expression by OsTGAP1, but other MEP pathway genes were not included among the OsTGAP1 target genes. Collectively, these results suggest that OsTGAP1 participates in the enhanced accumulation of diterpenoid phytoalexins, primarily through mechanisms other than the direct transcriptional regulation of the genes involved in the biosynthetic pathway of these phytoalexins. PMID:25157897

  20. Selective uptake, distribution, and redistribution of (109)Cd, (57)Co, (65)Zn, (63)Ni, and (134)Cs via xylem and phloem in the heavy metal hyperaccumulator Solanum nigrum L.

    PubMed

    Wei, Shuhe; Anders, Iwona; Feller, Urs

    2014-06-01

    The focus of this article was to explore the translocation of (109)Cd, (57)Co, (65)Zn, (63)Ni, and (134)Cs via xylem and phloem in the newly found hyperaccumulator Solanum nigrum L. Two experiments with the uptake via the roots and transport of (109)Cd, (57)Co, and (65)Zn labeled by roots, and the redistribution of (109)Cd, (65)Zn, (57)Co, (63)Ni, and (134)Cs using flap label in S. nigrum in a hydroponic culture with a standard nutrient solution were conducted. The results showed that (109)Cd added for 24 h to the nutrient medium of young plants was rapidly taken up, transferred to the shoot, and accumulated in the cotyledons and the oldest leaves but was not efficiently redistributed within the shoot afterward leading to a rather low content in the fruits. In contrast, (57)Co was more slowly taken up and released to the shoot, but afterward, this element was redistributed from older leaves to younger leaves and maturing fruits. (65)Zn was rapidly taken up and transferred to the shoot (mainly to the youngest leaves and not to the cotyledons). Afterward, this radionuclide was redistributed within the shoot to the youngest organs and finally accumulated in the maturing fruits. After flap labeling, all five heavy metals tested ((109)Cd, (57)Co, (65)Zn, (63)Ni, (134)Cs) were exported from the labeled leaf and redistributed within the plant. The accumulation in the fruits was most pronounced for (63)Ni and (65)Zn, while a relatively high percentage of (57)Co was finally found in the roots. (134)Cs was roughly in the middle of them. The transport of (109)Cd differed from that previously reported for wheat or lupin and might be important for the potential of S. nigrum to hyperaccumulate cadmium. PMID:24604268

  1. Hyperaccumulation of (18)F-FDG in order to differentiate solid pseudopapillary tumors from adenocarcinomas and from neuroendocrine pancreatic tumors and review of the literature.

    PubMed

    Guan, Zhi-wei; Xu, Bai-xuan; Wang, Rui-min; Sun, Lu; Tian, Jia-he

    2013-01-01

    Solid pseudopapillary tumors (SPT) are rare, unique pancreatic tumors with benign entity and low malignant potential. Limited information is available in the literature reporting their accumulation of fluorine-18 fluoro deoxyglucose ((18)F-FDG) using positron emission tomography/computed tomography (PET/CT). The aim of this retrospective study was to define t he uptake-accumulation of (18)F-FDG PET/CT in a comparatively large cohort of SPT, and to compare their uptake with the uptake of (18)F-FDG in pancreatic ductal adenocarcinomas (PAC) and neuroendocrine tumors (PNET). Between June 2007 and January 2013, 18 pathologically proven SPT were identified from the total of patients studied by PET/CT in our Center, including 13 women and 5 men, aging from 23 to 56 years old (mean age, 38.5 years). Malignant SPT was histologically classified using the WHO criteria. Eighty-six PAC patients and 28 PNET patients were also identified and included in this study for comparison. Positron emission tomography results were considered as positive if focal accumulation of (18)F-FDG exceeded the surrounding normal pancreatic tissue. Regions of interest were drawn on the pancreatic lesions, and the maximal standardized uptake values (SUVmax values) were calculated. The mean values of SUVmax were compared with independent-samples t test or with the nonparametric Mann-Whitney U method. Correlation of SUVmax values and tumor size were analyzed in cases of SPT. Receiver operating characteristics (ROC curve) were used to study the efficiency of SUV values for the differential diagnosis between SPT versus (vs) PAC and SPT vs PNET. A value of P<0.05 was considered statistically significant. All SPT cases were (18)F-FDG-PET positive, with SUVmax values ranging from 3.5-18.3. The SUVmax values of SPT had poor correlation with tumor size, and no significant difference by gender and age. Areas under the curve ROC were 0.619 and 0.526, respectively for the differentiation of SPT from PNET and PAC tumors. Five SPT tumors were malignant, and exhibited relatively low (18)F-FDG uptake (SUVmax range, 3.0-4.5) except a tumor after recurrence (SUVmax 17.7). Images of CT were of low dose and thus were not evaluated. In conclusion, our results suggest that SPT benign or malignant are consistently hyperaccumulating (18)F-FDG above SUVmax 3. Differentiation from PAC and PNET if only based on the higher SUVmax values was not possible but if based on lower SUVmax, of ?2.6 (in 14%) and ?2.5 (in 21,4%) of PAC and PNET, respectively, these pancreatic tumors could be differentiated from SPT. PMID:23687644

  2. Amino Acid Features of P1B-ATPase Heavy Metal Transporters Enabling Small Numbers of Organisms to Cope with Heavy Metal Pollution

    PubMed Central

    Ashrafi, E.; Alemzadeh, A.; Ebrahimi, M.; Ebrahimie, E.; Dadkhodaei, N.; Ebrahimi, M.

    2011-01-01

    Phytoremediation refers to the use of plants for extraction and detoxification of pollutants, providing a new and powerful weapon against a polluted environment. In some plants, such as Thlaspi spp, heavy metal ATPases are involved in overall metal ion homeostasis and hyperaccumulation. P1B-ATPases pump a wide range of cations, especially heavy metals, across membranes against their electrochemical gradients. Determination of the protein characteristics of P1B-ATPases in hyperaccumulator plants provides a new opportuntity for engineering of phytoremediating plants. In this study, using diverse weighting and modeling approaches, 2644 protein characteristics of primary, secondary, and tertiary structures of P1B-ATPases in hyperaccumulator and nonhyperaccumulator plants were extracted and compared to identify differences between proteins in hyperaccumulator and nonhyperaccumulator pumps. Although the protein characteristics were variable in their weighting, tree and rule induction models; glycine count, frequency of glutamine-valine, and valine-phenylalanine count were the most important attributes highlighted by 10, five, and four models, respectively. In addition, a precise model was built to discriminate P1B-ATPases in different organisms based on their structural protein features. Moreover, reliable models for prediction of the hyperaccumulating activity of unknown P1B-ATPase pumps were developed. Uncovering important structural features of hyperaccumulator pumps in this study has provided the knowledge required for future modification and engineering of these pumps by techniques such as site-directed mutagenesis. PMID:21573033

  3. Thlaspi arvense (Pennycress) germination, bolting and mechanical harvest seed loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress is being developed as an off-season rotation crop between annual corn and soybean production. This rotation scheme may offer distinct advantages to farmers by providing additional farm income from an otherwise fallow season with little impact on the subsequent soybean production. The seed...

  4. Identification and validation of heavy metal and radionuclide accumulating terrestrial plant species. Quarterly technical progress report, June 21, 1995--September 20, 1995

    SciTech Connect

    Kochian, L.

    1995-12-31

    This quarterly report describes experiments on uptake of a variety of heavy metals by plants. Titles of report sections are (1) Alleviation of heavy-metal induced micronutrient deficiency through foliar fertilization, (2) Second screen for Zn, Cu, and Cd accumulation, (3) Characterization of the root Zn hyperaccumulation by Thlaspi caerulescens, (4) Comparison of commercial Brassica accessions obtained from the Iowa seed bank, (5) Second screening experiment for the accumulation of Cs and Sr by plants, (6) Effect of Ca on Cs and Sr accumulation by selected dicot species, and (7) Preliminary investigations into the forms of uranium taken up by plants.

  5. Phytoremediation of heavy metal polluted soils and water: Progresses and perspectives*

    PubMed Central

    Lone, Mohammad Iqbal; He, Zhen-li; Stoffella, Peter J.; Yang, Xiao-e

    2008-01-01

    Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources. Phytoremediation, being more cost-effective and fewer side effects than physical and chemical approaches, has gained increasing popularity in both academic and practical circles. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come. This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources. PMID:18357623

  6. Genetic and Molecular Dissection of Arsenic Hyperaccumulation

    SciTech Connect

    Banks, Jo Ann

    2005-06-01

    We have constructed cDNA libraries from RNA isolated from arsenic treated gametophytes of the fern Pteris vittata. This library was made in a manner that allows each cDNA clone to be expressed in yeast. We have introduced this library into yeast cells, both wild type and arsensic sensitive mutants, and selected transformed yeast colonies with increased arsenic tolerance compared to the parental strains. From these screens we have identified putative homologs of the yeast ACR2 and ACR3 genes from Pteris vittata and, for the past year, have focused on characterizing the function of the ACR2 gene. In yeast, ACR2 is an arsenate reductase that is essential for arsenate tolerance. We refer to the Pteris vittata ACR2 gene as PvACR2. The deduced amino acid sequence of PvACR2 is highly similar to the yeast ACR2 and other related phosphatases.

  7. Rhizosphere Characteristics of the Arsenic Hyperaccumulator Pteris

    E-print Network

    Ma, Lena

    in thin films (DGT). Modeling of the DGT-soil system was able to show that the rate of release from solid fraction, DGT can be used as a monitoring tool to evaluate the efficiency of phytoextraction and to study

  8. Accumulation and hyperaccumulation of copper in plants

    NASA Astrophysics Data System (ADS)

    Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

    2009-04-01

    Copper is natural component of our environment. Flow of copper(II) ions in the environment depends on solubility of compounds containing this metal. Mobile ion coming from soil and rocks due to volcanic activity, rains and others are then distributed to water. Bio-availability of copper is substantially lower than its concentration in the aquatic environment. Copper present in the water reacts with other compounds and creates a complex, not available for organisms. The availability of copper varies depending on the environment, but moving around within the range from 5 to 25 % of total copper. Thus copper is stored in the sediments and the rest is transported to the seas and oceans. It is common knowledge that copper is essential element for most living organisms. For this reason this element is actively accumulated in the tissues. The total quantity of copper in soil ranges from 2 to 250 mg / kg, the average concentration is 30 mg / kg. Certain activities related to agriculture (the use of fungicides), possibly with the metallurgical industry and mining, tend to increase the total quantity of copper in the soil. This amount of copper in the soil is a problem particularly for agricultural production of food. The lack of copper causes a decrease in revenue and reduction in quality of production. In Europe, shows the low level of copper in total 18 million hectares of farmland. To remedy this adverse situation is the increasing use of copper fertilizers in agricultural soils. It is known that copper compounds are used in plant protection against various illnesses and pests. Mining of minerals is for the development of human society a key economic activity. An important site where the copper is mined in the Slovakia is nearby Smolníka. Due to long time mining in his area (more than 700 years) there are places with extremely high concentrations of various metals including copper. Besides copper, there are also detected iron, zinc and arsenic. Various plant species have adapted on such stress. The aim of this study is to investigate the behaviour of copper in plants and to assess its potential effect on the surrounding environment. To detect copper in biological samples electrochemical methods were employed particularly differential pulse voltammetry (DPV). Copper gave signals at 0.02 V measured by DPV. The obtained calibration dependence was linear (R2 = 0.995). Further, this method was utilized for determination of copper in real soil samples obtained from previously mentioned heavy-metal-polluted mining area. The content varied within range from tens to hundreds of mg of copper per kg of the soil. Moreover, we focused on investigation of copper influence on seedlings of Norway spruce. The seedlings were treated with copper (0, 0.1, 10 and 100 mM) for four weeks. We observed anatomical-morphological changes and other biochemical parameters in plants. We determined that seedlings synthesized more than 48 % protective thiols (glutathione and phytochelatins) compared to control ones. We investigated copper distribution in plant tissues by diphenylcarbazide staining. We found out that copper is highly accumulated in parenchymal stalk cells. In needles, change in auto-fluorescence of parenchymal cells of mesoderm similarly to endodermis cells. Besides, we analyzed samples of plants from the polluted area (spruce, pin, birch). The data obtained well correlated with previously mentioned. Acknowledgement The work on this experiment was supported by grant: INCHEMBIOL MSM0021622412.

  9. Thlaspi arvense (Pennycress): An off-season energy crop within the corn-soybean rotation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress is being developed as an off-season rotation crop between annual corn and soybean production. This rotation scheme may offer distinct advantages to farmers by providing additional farm income from an otherwise fallow season with little impact on the subsequent soybean production. The seed...

  10. Parental overwintering history affects the responses of Thlaspi arvense to warming winters in the North

    Microsoft Academic Search

    Timo Saarinen; Robin Lundell; Helena Åström; Heikki Hänninen

    2011-01-01

    The overwintering conditions of northern plants are expected to change substantially due to global warming. For perennial plants, winter warming may increase the risk of frost damage if the plants start dehardening prematurely. On the other hand, evergreen plants may remain photosynthetically active and thereby benefit from milder winters. The positive and negative effects of mild winters on annual plants

  11. Isolation and enrichment of the erucic acid from Thlaspi Arvense (Pennycress) oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress is being developed as an off-season rotation crop between annual corn and soybean production. This rotation scheme may offer distinct advantages to farmers by providing additional farm income from an otherwise fallow season with little impact on the subsequent soybean production. The seed...

  12. BibchemlbalSystematicsandEco/ogy, Vol.8, pp 43 to 50 0305 1978/80/0301 0043$0200/0 :i~'PergamonPressLtd. 1980.Printedin England

    E-print Network

    Chew, Frances Sze-Ling

    /lis, and Thlaspi montanum; (c) Erysimum asperum, which is unconditionally rejected by both adults and larvae spectabilis ~ + + + Thlaspi rnontanum ~ + + + ErysJmum asperum Chonspora tenel/a n + + _ Thlaspi arvense n

  13. RESEARCH PAPER Antioxidant responses of hyper-accumulator and

    E-print Network

    Ma, Lena

    Mrittunjai Srivastava1 , Lena Q. Ma1, *, Nandita Singh2 and Shraddha Singh3 1 Soil and Water Science concentration in the growth medium, the most being found in P. vittata fronds showing no toxicity symptoms three fern species. Thiobarbituric acid- reacting substances, indicators of stress in plants, were found

  14. IN VIVO SYNCHROTRON INVESTIGATION OF THALLIUM HYPERACCUMULATION - I

    EPA Science Inventory

    Thallium (TI) is a metal of great toxicological concern and its prevalence in the natural environment has steadily increased as a result of manufacturing and combustion practices. Due to its low natural abundance and the increasing demand, TI recovery and reuse could be a profita...

  15. Growth and cadmium uptake of Swiss chard, Thlaspi caerulescens and corn in pH adjusted biosolids amended soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Before regulations were established, some biosolids applications added higher Cd levels than presently permitted. Cadmium phytoextraction from such soils would alleviate constraints on land use. Unamended farm soil, and biosolids amended farm soil and mine soil were obtained from Fulton County, Il...

  16. Phytoextraction of Zn and Cu from sewage sludge and impact on agronomic characteristics.

    PubMed

    Xiaomei, Liu; Qitang, Wu; Banks, M K; Ebbs, S D

    2005-01-01

    The presence of elevated concentrations of heavy metals limits the usage of sewage sludge as a fertilizer and soil amendment. Experiments were carried out to examine the extent to which seven plant species phytoextracted Zn and Cu from dewatered sludge. The hyperaccumulators Thlaspi caerulescens and Sedum alfredii showed the greatest removal of Zn, while shoots and tubers of two species of Alocasia showed the greatest Cu removal. Cultivation of plants in the sludge resulted in significant decreases in total Zn and changes in the partitioning of Zn between soil pools. However, Cu levels were largely unchanged and remained associated predominantly with the organic matter pool. Agronomic characteristics of the sludge material, such as pH, organic matter content, and nitrogen, phosphorus, and potassium concentrations, did not change significantly during the four-month growth period, indicating that subsequent crops could be sustained by this material. These results suggest that Zn can be phytoextracted from sludge material, provided the rate of metal uptake exceeds the rate of mobilization to the exchangeable fraction. Since there was no appreciable accumulation of Zn and Cu in seeds of Zea mays in this study, some tissues from sludge-grown plants could potentially be used as animal fodder. PMID:15792302

  17. Variation in HMA4 gene copy number and expression among Noccaea caerulescens populations presenting different levels of Cd tolerance and accumulation.

    PubMed

    Craciun, Adrian R; Meyer, Claire-Lise; Chen, Jiugeng; Roosens, Nancy; De Groodt, Ruth; Hilson, Pierre; Verbruggen, Nathalie

    2012-06-01

    There is huge variability among populations of the hyperaccumulator Noccaea caerulescens (formerly Thlaspi caerulescens) in their capacity to tolerate and accumulate cadmium. To gain new insights into the mechanisms underlying this variability, we estimated cadmium fluxes and further characterized the N. caerulescens heavy metal ATPase 4 (NcHMA4) gene in three populations (two calamine, Saint-Félix-de-Pallières, France and Prayon, Belgium; one serpentine, Puente Basadre, Spain) presenting contrasting levels of tolerance and accumulation. Cadmium uptake and translocation varied among populations in the same way as accumulation; the population with the highest cadmium concentration in shoots (Saint Félix-de-Pallières) presented the highest capacity for uptake and translocation. We demonstrated that the four NcHMA4 copies identified in a previous study are not fixed at the species level, and that the copy truncated in the C-terminal part encodes a functional protein. NcHMA4 expression and gene copy number was lower in the serpentine population, which was the least efficient in cadmium translocation compared to the calamine populations. NcHMA4 expression was associated with the vascular tissue in all organs, with a maximum at the crown. Overall, our results indicate that differences in cadmium translocation ability of the studied populations appear to be controlled, at least partially, by NcHMA4, while the overexpression of NcHMA4 in the two calamine populations may result from convergent evolution. PMID:22581842

  18. Remediation of cadmium contaminated irrigation and drinking water: a large scale approach.

    PubMed

    Bandara, J M R S; Wijewardena, H V P; Seneviratne, H M M S

    2010-09-15

    Cadmium is one of the most troublesome toxic heavy metals. It accumulates in the water reservoirs and agricultural soil as a result of intensive use of Cd contaminated phosphate fertilizers, e.g. in agriculture in the North Central Province (NCP) of Sri Lanka. The hyper-accumulator Thlaspi caerulescens, accumulates up to 1000 ppm Cd in shoots without exhibiting toxicity symptoms. The storage rhizomes of year old Nelumbo nucifera (lotus) natural vegetation in water reservoirs in NCP accumulated 253+/-12 mg Cd/kg. Seedlings of lotus grown in 5% Hoagland's solution at 0.75, 1.0 and 1.25 ppm cadmium sulphate showed a significant increase in Cd removal of 0.0334-0.121 ppm/week. However the removal rate of Cd from water failed to increase any further at higher concentrations of Cd in water. The slow growth rate and low rate of phytoextraction demands a more effective but an affordable method of remediation in order to combat the prevailing elevated cadmium levels in NCP that causes chronic renal failure (CRF). We have developed a large scale filtering device using rice husk. We have achieved successful results in sequestering Cd using raw rice husk as well as amorphous silica derived from rice husk. PMID:20466045

  19. Effects of selenium on arsenic uptake in arsenic hyperaccumulator Pteris vittata L. Mrittunjai Srivastava a,1

    E-print Network

    Ma, Lena

    Srivastava a,1 , Lena Q. Ma a,*, Bala Rathinasabapathi b , Pratibha Srivastava a,1 a Soil and Water Science-metallic element, which has the capability to increase the antioxidative capacity and stress tolerance of plants possible mechanisms of interaction. Pteris vittata plants were exposed hydroponically to 0, 150 or 300 l

  20. Chemical Form and Distribution of Selenium and Sulfur in the Selenium Hyperaccumulator Astragalus bisulcatus1

    PubMed Central

    Pickering, Ingrid J.; Wright, Carrie; Bubner, Ben; Ellis, Danielle; Persans, Michael W.; Yu, Eileen Y.; George, Graham N.; Prince, Roger C.; Salt, David E.

    2003-01-01

    In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower, and selenate predominates. Seleno-Cys methyltransferase is the enzyme responsible for the biosynthesis of Se-methylseleno-Cys from seleno-Cys and S-methyl-methionine. Seleno-Cys methyltransferase is found to be expressed in A. bisulcatus leaves of all ages, and thus the biosynthesis of Se-methylseleno-Cys in older leaves is limited earlier in the metabolic pathway, probably by an inability to chemically reduce selenate. A comparative study of sulfur (S) and Se in A. bisulcatus using x-ray absorption spectroscopy indicates similar trends for oxidized and reduced Se and S species, but also indicates that the proportions of these differ significantly. These results also indicate that sulfate and selenate reduction are developmentally correlated, and they suggest important differences between S and Se biochemistries. PMID:12644695

  1. Arsenic transformation in the growth media and biomass of hyperaccumulator Pteris vittata L.

    PubMed

    Mathews, Shiny; Ma, Lena Q; Rathinasabapathi, Bala; Natarajan, Seenivasan; Saha, Uttam K

    2010-11-01

    This study determined the role of plant and microbes in arsenite (AsIII) oxidation in the growth media and the location of AsIII oxidation and arsenate (AsV) reduction in Pteris vittata tissues. P. vittata grew in 0.10-0.27mM AsV or AsIII solution under aerated or sterile condition for 1h to 14d. Arsenic speciation was conducted in the growth media, biomass (roots, rhizomes, rachis, pinnae, and fronds), and sap (rhizomes and fronds). Arsenite was rapidly oxidized in the growth media by microbes (18-67% AsV after 1d) and was then further oxidized in the roots of P. vittata (35% AsV in the roots growing in AsIII media). While limited reduction occurred in the roots (7-8% as AsIII), AsV reduction mostly occurred in the rhizomes (68-71% as AsIII) and pinnae (>90% as AsIII) of P. vittata. Regardless AsIII or AsV was supplied, AsV dominated in the roots while AsIII dominated in the rhizomes and fronds. AsIII translocation from the roots to the fronds was more rapid than AsV. This study shed new insights into arsenic transformation in the growth media and P. vittata biomass and raise new question into the tissue distribution of arsenic reducing and oxidizing enzymes in P. vittata. PMID:20566284

  2. Arsenic Hyperaccumulator Fern Pteris vittata : Utilities for Arsenic Phytoremediation and Plant Biotechnology

    Microsoft Academic Search

    Bala Rathinasabapathi

    \\u000a Arsenic is a toxic metalloid that is widespread in the environment due to both man-made and natural causes. Soils, food, and\\u000a ground water contaminated with arsenic pose serious health risks to millions of people in different parts of the World. While\\u000a engineering methods to remediate arsenic-contaminated environments are available, they are often prohibitively expensive and\\u000a cumbersome. It was discovered about

  3. Zinc Hyperaccumulation in Squirrelfish (Holocentrus adscenscionis) and Its Role in Embryo Viability

    PubMed Central

    Glover, Chris N.; Capo, Tom; Walsh, Patrick J.; Hogstrand, Christer

    2012-01-01

    Female squirrelfish (Fam. Holocentridae) can accumulate and temporarily sequester copious amounts of zinc (Zn) in their livers. There, it is initially compartmentalized before a subsequent, estrogen-triggered redistribution to the ovaries. Here we show that cellular uptake of Zn is also influenced by estrogen signaling, and that estrogen increases concentrations of the plasma Zn-binding protein vitellogenin (VTG). However, estrogen-mediated increases in VTG are not sufficient to accommodate the magnitude of hepato-ovarian Zn transfer in female squirrelfish (Holocentrus adscensionis). These findings suggest that holocentrids have acquired the ability to use hormonal cues to drive hepatic uptake and storage of Zn, signal for its physiological redistribution, and influence the capacity for systemic transport of Zn beyond the mediation of increased plasma VTG concentrations. Such specific adaptations suggest an advantage for the oocyte, which is corroborated in further studies where we determined that oocyte Zn concentrations are positively correlated with egg viability in captive-spawned squirrelfish. The novel nature of these findings underlies the importance of Zn in squirrelfish reproductive biology. PMID:23056248

  4. Nickel hyperaccumulation by Streptanthus polygaloides protects against the folivore Plutella xylostella (Lepidoptera: Plutellidae)

    Microsoft Academic Search

    Edward M. Jhee; Robert S. Boyd; Micky D. Eubanks; Micheal A. Davis

    2006-01-01

    We determined the effectiveness of Ni as an elemental defence of Streptanthus polygaloides (Brassicaceae) against a crucifer specialist folivore, diamondback moth (DBM), Plutella xylostella. An oviposition experiment used arrays of S. polygaloides grown on Ni-amended (high-Ni) soil interspersed with plants grown on unamended (low-Ni) soil and eggs were allowed to hatch and larvae fed freely among plants in the arrays.

  5. CHARACTERIZATION OF ARSENIC RESISTANT BACTERIAL COMMUNITIES IN THE RHIZOSPHERE OF AN ARSENIC HYPERACCUMULATOR Pteris vittata L.

    E-print Network

    Ma, Lena

    CHARACTERIZATION OF ARSENIC RESISTANT BACTERIAL COMMUNITIES IN THE RHIZOSPHERE OF AN ARSENIC..................................................................................................................11 1.1 Environmental Sources of Arsenic..................................................................................11 1.1.1 Arsenic in the Environment

  6. Chemical form and distribution of selenium, sulfur in the selenium hyperaccumulator astragalus bisulcatus

    Microsoft Academic Search

    Ingrid J. Pickering; Carrie Wright; Ben Bubner; Danielle Ellis; Michael W. Persans; Eileen Y. Yu; Graham N. George; Roger C. Prince; David E. Salt

    2003-01-01

    In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w\\/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower,

  7. Bioenergy crops grown for hyperaccumulation of phosphorous in the Delmarva Peninsula and their biofuels potential.

    PubMed

    Boateng, Akwasi A; Serapiglia, Michelle J; Mullen, Charles A; Dien, Bruce S; Hashem, Fawzy M; Dadson, Robert B

    2015-03-01

    Herbaceous bioenergy crops, including sorghum, switchgrass, and miscanthus, were evaluated for their potential as phytoremediators for the uptake of phosphorus in the Delmarva Peninsula and their subsequent conversion to biofuel intermediates (bio-oil) by fast pyrolysis using pyrolysis-gas chromatography/mass spectroscopy. Four cultivars of sorghum, five cultivars of switchgrass and one miscanthus (Miscanthus × giganteus) were grown in soils with two different levels of poultry manure (PM) applications. Little variation was seen in phosphorus uptake in the two different soils indicating that the levels of available phosphorus in the soil already saturated the uptake ability of the plants. However, all plants regardless of trial took up more phosphorus than that measured for the non- PM treated control. Sorghum accumulated greater levels of nutrients including phosphorus and potassium compared to switchgrass and miscanthus. The levels of these nutrients in the biomass did not have an effect on carbohydrate contents. However, the potential yield and composition of bio-oil from fast pyrolysis were affected by both agronomics and differences in mineral concentrations. PMID:25460422

  8. Mechanisms of nickel uptake, and hyperaccumulation by plants and implications to soil remediation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil contamination by heavy metals like Ni was originally restricted to metalliferous soils but in recent years it has become a general problem due to the increasingly frequent anthropogenic activities. Because of the characteristics of cost-effectiveness, environmental friendliness, and fewer side...

  9. Phytoremediation of uranium-contaminated soils: Role of organic acids in triggering uranium hyperaccumulation in plants

    Microsoft Academic Search

    Jianwei W. Huang; Michael J. Blaylock; Yoram Kapulnik; Burt D. Ensley

    1998-01-01

    Uranium phytoextraction, the use of plants to extract U from contaminated soils, is an emerging technology. The authors report on the development of this technology for the cleanup of U-contaminated soils. In this research, they investigated the effects of various soil amendments on U desorption from soil to soil solution, studied the physiological characteristics of U uptake and accumulation in

  10. Using phosphate rock to immobilize metals in soil and increase arsenic uptake by hyperaccumulator Pteris vittata

    E-print Network

    Ma, Lena

    -effective amendment for phytoremediation of arsenic and metal polluted soils. D 2005 Elsevier B.V. All rights reserved. Keywords: Phosphate rock; Arsenic; Lead; Cadmium; Zinc; Phytoremediation 1. Introduction Arsenic biomass coupled with its large biomass makes it ideal for phytoremediation. Our previous research has

  11. Plant and Environment Interactions Arsenic Accumulation in the Hyperaccumulator Chinese Brake and Its Utilization

    E-print Network

    Ma, Lena

    and Its Utilization Potential for Phytoremediation Cong Tu, Lena Q. Ma,* and Bhaskar Bondada ABSTRACT in the phytoremediation of arsenic-contaminated soils. The the past few decades, much effort has been devoted (0.030­0.200) lettuce (0.020­0.250) mossesmated that the phytoremediation market in the United

  12. MOLECULAR DISSECTION OF THE CELLULAR MECHANISMS INVOLVED IN NICKEL HYPERACCUMULATION IN PLANTS

    EPA Science Inventory

    Phytoremediation, the use of plants for environmental cleanup of pollutants, including toxic metals, holds the potential to allow the economic restoration of heavy metal and radionuclide contaminated sites. A number of terrestrial plants are known to naturally accumulate high le...

  13. Characterization of arsenic-resistant endophytic bacteria from hyperaccumulators Pteris vittata and Pteris multifida

    E-print Network

    Ma, Lena

    alteration (Ali et al., 2009). So it is important to reduce its environmental impact. Phytoremediation, there are several limiting factors affecting its effectiveness (Shin et al., 2012). To enhance phytoremediation potential in enhancing phytoremediation (Ryan et al., 2008; Weyen

  14. Mechanisms of Arsenic Hyperaccumulation in Pteris vittata. Uptake Kinetics, Interactions with Phosphate, and Arsenic Speciation

    Microsoft Academic Search

    Junru Wang; Fang-Jie Zhao; Andrew A. Meharg; Andrea Raab; Joerg Feldmann; Steve P. McGrath

    2002-01-01

    vittata accumulated As in the fronds up to 27,000 mg As kg1 dry weight, and the frond As to root As concentration ratio varied between 1.3 and 6.7. Increasing phosphate supply decreased As uptake markedly, with the effect being greater on root As concentration than on shoot As concentration. Increasing arsenate supply decreased the P concentration in the roots, but

  15. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

    USGS Publications Warehouse

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

  16. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

    USGS Publications Warehouse

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

  17. Bioenergy crops grown for hyperaccumulation of phosphorus in the delmarva peninsula and their biofuels potential

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous bioenergy crops, including sorghum, switchgrass, and miscanthus, were evaluated for their potential as phytoremedators for the uptake of phosphorus in the Delmarva Peninsula and their subsequent conversion to biofuel intermediates (bio-oil) by fast pyrolysis using pyrolysis-gas chromatogr...

  18. Effects of selenium hyperaccumulation on plantplant interactions: evidence for elemental allelopathy?

    E-print Network

    and Se concentration in two plant species (Artemisia ludoviciana and Symphyotrichum ericoides) growing- accumulators. The Se concentration was higher in neighboring species A. ludoviciana and S. ericoides when

  19. Arsenic enhanced plant growth and altered rhizosphere characteristics of hyperaccumulator Pteris vittata

    E-print Network

    Ma, Lena

    Accepted 11 July 2014 Available online Keywords: Arsenic Speciation P. vittata Rhizosphere DGT a b s t rÀ1 arsenate (AsVÀsoil) or arsenite (AsIIIÀsoil). Diffusive gradients in thinÀfilms technique (DGT in thin films technique (DGT) uses a layer of bind

  20. Chemical form and distribution of selenium and sulfur in the selenium hyperaccumulator Astragalus bisulcatus.

    PubMed

    Pickering, Ingrid J; Wright, Carrie; Bubner, Ben; Ellis, Danielle; Persans, Michael W; Yu, Eileen Y; George, Graham N; Prince, Roger C; Salt, David E

    2003-03-01

    In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower, and selenate predominates. Seleno-Cys methyltransferase is the enzyme responsible for the biosynthesis of Se-methylseleno-Cys from seleno-Cys and S-methyl-methionine. Seleno-Cys methyltransferase is found to be expressed in A. bisulcatus leaves of all ages, and thus the biosynthesis of Se-methylseleno-Cys in older leaves is limited earlier in the metabolic pathway, probably by an inability to chemically reduce selenate. A comparative study of sulfur (S) and Se in A. bisulcatus using x-ray absorption spectroscopy indicates similar trends for oxidized and reduced Se and S species, but also indicates that the proportions of these differ significantly. These results also indicate that sulfate and selenate reduction are developmentally correlated, and they suggest important differences between S and Se biochemistries. PMID:12644695

  1. MICROSPECTROSCOPIC STUDY OF COBALT SPECIATION AND LOCALIZATION IN HYPERACCUMULATOR ALYSSUM MURALE

    E-print Network

    Sparks, Donald L.

    fulfillment of the requirements for the degree of Doctor of Philosophy in Plant and Soil Sciences Winter 2009 of the Department of Plant and Soil Sciences Approved of the Plant and Soil Science Department (PLSC) for their friendliness and willingness to help (especially

  2. Identifying root exudates in field contaminated soil systems

    NASA Astrophysics Data System (ADS)

    Rosenfeld, C.; Martinez, C. E.

    2012-12-01

    Carbon (C) compounds exuded from plant roots comprise a significant and reactive fraction of belowground C pools. These exudates substantially alter the soil directly surrounding plant roots and play a vital role in the global C cycle, soil ecology, and ecosystem mobility of both nutrients and contaminants. In soils, the solubility and bioavailability of metals such as iron, zinc, and cadmium are intricately linked to the quantity and chemical characteristics of the C compounds allocated to the soil by plants. Cadmium (Cd), a toxic heavy metal, forms stronger bonds with reduced S- and N-containing compounds than with carboxylic acids, which may influence exudate composition in hyperaccumulator and tolerant plants grown in Cd contaminated soils. We hypothesize that hyperaccumulator plants will exude a larger quantity of aromatic N and chelating di- and tri-carboxylic acid molecules, while plants that exclude heavy metals from uptake will exude a larger proportion of reduced S containing molecules. This study examines how a variety of techniques can measure the low concentrations of complex organic mixtures exuded by hyperaccumulator and non-hyperaccumulator plants grown in Cd-contaminated soils. Two congeneric plants, Thlaspi caerulescens (Ganges ecotype), and T. caerulescens (Prayon ecotype) were grown in 0.5 kg pots filled with Cd-contaminated field soils from Chicago, IL. Field soils were contaminated as a result of the application of contaminated biosolids in the 1960's and 1970's. Pots were fitted for rhizon soil moisture samplers, micro-lysimeters developed for in situ collection of small volumes in unsaturated soils, prior to planting. Plants were grown for 8 weeks before exudate collection. After the 8 weeks of growth, a pulse-chase isotope tracer method using the C stable isotope, 13C, was employed to differentiate plant-derived compounds from background soil and microbial-derived compounds. Plants were placed in a CO2 impermeable chamber, and the soil surface was covered by CO2 impermeable sheets to ensure that all 13C in the soil results from photoassimilated C released by roots and not soil-atmosphere gas exchange. Ambient CO2 was drawn down in the system until the CO2 concentration within the tent was less than 50 ppm, after which the labeled 13CO2 was introduced, returning the CO2 concentration to the ambient level (~375 ppm). The CO2 pulse lasted for 60 minutes to allow enough time for 13C assimilation within the plants. In order to determine the ideal sampling time, soil pore water samples were extracted every 1-2 hours following the 13C pulse application, over the course of 24 hours. Samples were analyzed for delta 13C as well as %C, and results indicate that the greatest plant-derived dissolved organic C is present at about 6 hours following the 13C pulse. A second experiment will also be conducted using a combination of NMR and mass spectrometry methods to obtain detailed information regarding chemical structures within exudate samples.

  3. Are plants growing at abandoned mine sites suitable for phytoremediation of contaminated soils?

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Buffa, Gabriella; Fontana, Silvia; Wahsha, Mohammad

    2013-04-01

    Plants growing on abandoned mine sites are of particular interest in the perspective to remediate contaminated soils by phytoremediation, a low cost and environmental friendly technique which uses metal-accumulator plants to clean up moderately contaminated areas. The choice of plants is a crucial aspect for the practical use of this technique, given the ability to accumulate metals in their tissues, being genetically tolerant to high metal concentrations. Up today, more than 400 native plants that hyperaccumulate metals are reported, Brassicaceae being the family with the largest number of hyperaccumulator species. For example, Alyssum bertoloni is well known as Ni accumulator, as well as Thlaspi caerulescens for Zn and Brassica napus for Pb. However, metal hyperaccumulation is not a common phenomenon in terrestrial higher plants, and many of the European hyperaccumulator plants are of small biomass, and have a slow growth rate. Therefore, there is an urgent need for surveying and screening of plants with ability to accumulate metals in their tissues and a relatively high biomass. In recent years, a survey of soils and plants growing on contaminated areas at several abandoned sulphide mines in Italy was carried out by working groups of the Universities of Florence, Siena, Cagliari, Bologna, Udine and Venice, in order to evaluate the ability of these plants to colonize mine waste and to accumulate metals, in the perspective of an ecological restoration of contaminated sites. We investigated the heavy metal concentration of the waste material, and the soils developed from, in order to determine the extent of heavy metal dispersion, and the uptake by plants, and deserved attention to wild plants growing at that sites, to find out new metal-tolerant species to utilize in soil remediation. Current results of these investigations, with particular emphasis on the Tuscan areas, are reported here. All the studied profiles are strongly enriched in metals; their concentration, however, depends on the distance from mine areas, as indicated in the following table: Sample Metal Mean (ppm) Range (ppm) Waste soils ENTISOLS Cu 3527 62-10200 Pb 301 30-830 Zn 798 110-1950 Proximal soils INCEPTISOLS Cu 1081 16-3400 Pb 623 45-1900 Zn 792 420-1300 Distal soils ALFISOLS Cu 193 80-340 Pb 267 160-430 Zn 672 410-890 Wild plants (e.g. fescue, plantain, common reed, mint, marigold, dandelion, moon plant, rock-rose, willow) were found to be metal-tolerant and to accumulate high levels of As, Cd, Cr, Cu, Pb, Zn in their tissues (both roots and aerial parts), although at different extent in response to their metabolic activity, physiology, and to soil and environmental characteristics. In conclusion, the evaluation of metal uptake by plants, combined with geobotanical observations, is an useful tool to find tolerant plant populations to be used in revegetation programs aimed at reducing the environmental impact of contaminated areas.

  4. Does subcellular distribution in plants dictate the trophic bioavailability of cadmium to Porcellio dilatatus (Crustacea, Isopoda)?

    PubMed

    Monteiro, Marta S; Santos, Conceição; Soares, Amadeu M V M; Mann, Reinier M

    2008-12-01

    The present study examined how subcellular partitioning of Cd in plants with different strategies to store and detoxify Cd may affect trophic transfer of Cd to the isopod Porcellio dilatatus. The plant species used were Lactuca sativa, a horticultural metal accumulator species; Thlaspi caerulescens, a herbaceous hyperaccumulator species; and the nonaccumulator, T. arvense. Taking into account that differences in subcellular distribution of Cd in plants might have an important role in the bioavailability of Cd to a consumer, a differential centrifugation technique was adopted to separate plant leaf tissues into four different fractions: cell debris, organelles, heat-denatured proteins, and heat-stable proteins (metallothionein-like proteins). Plants were grown in replicate hydroponic systems and were exposed for 7 d to 100 microM Cd spiked with 109Cd. After a 14-d feeding trial, net assimilation of Cd in isopods following consumption of T. caerulescens and T. arvense leaves reached 16.0 +/- 2.33 and 21.9 +/- 1.94 microg/g animal, respectively. Cadmium assimilation efficiencies were significantly lower in isopods fed T. caerulescens (10.0 +/- 0.92%) than in those fed T. arvense (15.0 +/- 1.03%). In further experiments, Cd assimilation efficiencies were determined among isopods provided with purified subcellular fractions of the three plants. On the basis of our results, Cd bound to heat-stable proteins was the least bioavailable to isopods (14.4-19.6%), while Cd bound to heat-denatured proteins was the most trophically available to isopods (34.4-52.8%). Assimilation efficiencies were comparable in isopods fed purified subcellular fractions from different plants, further indicating the importance of subcellular Cd distribution in the assimilation. These results point to the ecological relevance of the subcellular Cd distribution in plants, which directly influence the trophic transfer of Cd to the animal consumer. PMID:18624580

  5. Abnormal accumulation of trace metals by plants

    SciTech Connect

    Reeves, R.D.; Brooks, R.R. [Massey Univ., Palmerston North (New Zealand); Baker, A.J.M. [Univ. of Sheffield (United Kingdom)

    1996-12-31

    The article describes the hyperaccumulation of metals by plants. Ranges for low, normal, high, and hyperaccumulating uptake are established. A partial list of hyperaccumulator species and their localities is included. Studies are reviewed and summarized for zinc, cadmium and lead, nickel, cobalt and copper, selenium, and cadmium and manganese hyperaccumulation.

  6. Impact Assessment of Mercury Accumulation and Biochemical and Molecular Response of Mentha arvensis: A Potential Hyperaccumulator Plant

    PubMed Central

    Manikandan, R.; Sahi, S. V.; Venkatachalam, P.

    2015-01-01

    The present study was focused on examining the effect of Hg oxidative stress induced physiochemical and genetic changes in M. arvensis seedlings. The growth rate of Hg treated seedlings was decreased to 56.1% and 41.5% in roots and shoots, respectively, compared to the control. Accumulation of Hg level in both roots and shoots was increased with increasing the concentration of Hg. Superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities were found to be increased with increasing the Hg concentration up to 20?mg/L; however, it was decreased at 25?mg/L?Hg concentration. The POX enzyme activity was positively correlated with Hg dose. The changes occurring in the random amplification of ploymorphic DNA (RAPD) profiles generated from Hg treated seedlings included variations in band intensity, disappearance of bands, and appearance of new bands compared with the control seedlings. It was concluded that DNA polymorphisms observed with RAPD profile could be used as molecular marker for the evaluation of heavy metal induced genotoxic effects in plant species. The present results strongly suggested that Mentha arvensis could be used as a potential phytoremediator plant in mercury polluted environment. PMID:25654134

  7. This paper reviews progress in phytoextraction of soil elements and illustrates the key role of hyperaccumulator plant species

    E-print Network

    Sparks, Donald L.

    of Cd. Production of element-enriched biomass with value as ore or fertilizer or improved food (Se1429 This paper reviews progress in phytoextraction of soil elements and illustrates the key role) or feed supplement may offset costs of phytoextraction crop production. Transgenic phytoextraction plants

  8. Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator,

    E-print Network

    Ma, Lena

    Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake, or biosolid compost. Phosphate amendments sig- nificantly enhanced plant As uptake from the two tested soils was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions

  9. Hyperaccumulation of Pb, Zn and Cd in herbaceous grown on lead–zinc mining area in Yunnan, China

    Microsoft Academic Search

    Zu Yanqun; Li Yuan; Chen Jianjun; Chen Haiyan; Qin Li; Christian Schvartz

    2005-01-01

    A field survey of herbaceous growing on lead–zinc mining area in Yunnan, China were conducted to identify species accumulating exceptionally large concentrations of Pb, Zn and Cd in shoots. In total, 220 plant samples of 129 species of 50 families and 220 soil samples in which the plants were growing were collected. According to accumulation concentration in plant shoots and

  10. Cd localization and speciation in a contaminated sdiment and in th Zn and Cd hy-peraccumulating plant Arabidopsis kalleri

    E-print Network

    Boyer, Edmond

    in a Zn- and Cd-contaminated dredged sédiment sub- jected to a phytoremediation treatment with thé of thé phytoremediation treatment. months in order to reduce its water content. Thereafter, thé sédiment in thé Nord-Pas de Calais région). Phytoremediation could be a way to treat thèse polluted sédi- ments

  11. Rhizosphere Microbial Community Composition Affects Cadmium and Zinc Uptake by the Metal-Hyperaccumulating Plant Arabidopsis halleri.

    PubMed

    Muehe, E Marie; Weigold, Pascal; Adaktylou, Irini J; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas; Behrens, Sebastian

    2015-03-15

    The remediation of metal-contaminated soils by phytoextraction depends on plant growth and plant metal accessibility. Soil microorganisms can affect the accumulation of metals by plants either by directly or indirectly stimulating plant growth and activity or by (im)mobilizing and/or complexing metals. Understanding the intricate interplay of metal-accumulating plants with their rhizosphere microbiome is an important step toward the application and optimization of phytoremediation. We compared the effects of a "native" and a strongly disturbed (gamma-irradiated) soil microbial communities on cadmium and zinc accumulation by the plant Arabidopsis halleri in soil microcosm experiments. A. halleri accumulated 100% more cadmium and 15% more zinc when grown on the untreated than on the gamma-irradiated soil. Gamma irradiation affected neither plant growth nor the 1 M HCl-extractable metal content of the soil. However, it strongly altered the soil microbial community composition and overall cell numbers. Pyrosequencing of 16S rRNA gene amplicons of DNA extracted from rhizosphere samples of A. halleri identified microbial taxa (Lysobacter, Streptomyces, Agromyces, Nitrospira, "Candidatus Chloracidobacterium") of higher relative sequence abundance in the rhizospheres of A. halleri plants grown on untreated than on gamma-irradiated soil, leading to hypotheses on their potential effect on plant metal uptake. However, further experimental evidence is required, and wherefore we discuss different mechanisms of interaction of A. halleri with its rhizosphere microbiome that might have directly or indirectly affected plant metal accumulation. Deciphering the complex interactions between A. halleri and individual microbial taxa will help to further develop soil metal phytoextraction as an efficient and sustainable remediation strategy. PMID:25595759

  12. Physiologia Plantarum 2013 2013 Scandinavian Plant Physiology Society, ISSN 0031-9317 Inoculation of selenium hyperaccumulator Stanleya pinnata

    E-print Network

    enhance root Se accumulation may be useful in Se biofortification or phytoremediation using root crop phytoremediation). Plant species differ in their capacity to accumulate Se. Most plants are sensitive to Se at high

  13. Impact Assessment of Mercury Accumulation and Biochemical and Molecular Response of Mentha arvensis: A Potential Hyperaccumulator Plant.

    PubMed

    Manikandan, R; Sahi, S V; Venkatachalam, P

    2015-01-01

    The present study was focused on examining the effect of Hg oxidative stress induced physiochemical and genetic changes in M. arvensis seedlings. The growth rate of Hg treated seedlings was decreased to 56.1% and 41.5% in roots and shoots, respectively, compared to the control. Accumulation of Hg level in both roots and shoots was increased with increasing the concentration of Hg. Superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities were found to be increased with increasing the Hg concentration up to 20?mg/L; however, it was decreased at 25?mg/L?Hg concentration. The POX enzyme activity was positively correlated with Hg dose. The changes occurring in the random amplification of ploymorphic DNA (RAPD) profiles generated from Hg treated seedlings included variations in band intensity, disappearance of bands, and appearance of new bands compared with the control seedlings. It was concluded that DNA polymorphisms observed with RAPD profile could be used as molecular marker for the evaluation of heavy metal induced genotoxic effects in plant species. The present results strongly suggested that Mentha arvensis could be used as a potential phytoremediator plant in mercury polluted environment. PMID:25654134

  14. Lead Uptake and Effects on Seed Germination and Plant Growth in a Pb Hyperaccumulator Brassica pekinensis Rupr

    Microsoft Academic Search

    Z.-T. Xiong

    1998-01-01

    Heavy metal contamination of soil, water and air has caused serious environmental hazard in the biosphere due to rapid industrialization and urbanization. Lead is probably one of the most frequently encountered heavy metals in polluted environment. The primary sources of this metal include mining and smelting of metalliferous ores, burning of leaded gasoline, disposal of municipal sewage and industrial wastes

  15. Biochemical Characterization of Plant Small CTD Phosphatases and Application of CTD Phosphatase Mutant in Hyperaccumulation of Flavonoids in Arabidopsis

    E-print Network

    Feng, Yue

    2011-10-21

    In addition to AtCPL1-4, the genome of Arabidopsis thaliana encodes a large number of putative acid phosphatases. The predicted Arabidopsis SCP1-like small phosphatases (SSP) are highly homologous to the catalytic domain of eukaryotic RNA polymerase...

  16. Complexation with dissolved organic matter and mobility control of heavy metals in the rhizosphere of hyperaccumulator Sedum alfredii

    E-print Network

    Sparks, Donald L.

    Complexation with dissolved organic matter and mobility control of heavy metals in the rhizosphere of free metal as a percentage of soluble metal varied from 22.1 to 42.5% for Zn2þ , from 8.1 to 15. alfredii could significantly increase metal mobility through the for- mation of soluble DOM-metal complexes

  17. Refeeding-Induced Brown Adipose Tissue Glycogen Hyper-Accumulation in Mice Is Mediated by Insulin and Catecholamines

    PubMed Central

    Carmean, Christopher M.; Bobe, Alexandria M.; Yu, Justin C.; Volden, Paul A.; Brady, Matthew J.

    2013-01-01

    Brown adipose tissue (BAT) generates heat during adaptive thermogenesis through a combination of oxidative metabolism and uncoupling protein 1-mediated electron transport chain uncoupling, using both free-fatty acids and glucose as substrate. Previous rat-based work in 1942 showed that prolonged partial fasting followed by refeeding led to a dramatic, transient increase in glycogen stores in multiple fat depots. In the present study, the protocol was replicated in male CD1 mice, resulting in a 2000-fold increase in interscapular BAT (IBAT) glycogen levels within 4–12 hours (hr) of refeeding, with IBAT glycogen stores reaching levels comparable to fed liver glycogen. Lesser effects occurred in white adipose tissues (WAT). Over the next 36 hr, glycogen levels dissipated and histological analysis revealed an over-accumulation of lipid droplets, suggesting a potential metabolic connection between glycogenolysis and lipid synthesis. 24 hr of total starvation followed by refeeding induced a robust and consistent glycogen over-accumulation similar in magnitude and time course to the prolonged partial fast. Experimentation demonstrated that hyperglycemia was not sufficient to drive glycogen accumulation in IBAT, but that elevated circulating insulin was sufficient. Additionally, pharmacological inhibition of catecholamine production reduced refeeding-induced IBAT glycogen storage, providing evidence of a contribution from the central nervous system. These findings highlight IBAT as a tissue that integrates both canonically-anabolic and catabolic stimulation for the promotion of glycogen storage during recovery from caloric deficit. The preservation of this robust response through many generations of animals not subjected to food deprivation suggests that the over-accumulation phenomenon plays a critical role in IBAT physiology. PMID:23861810

  18. Biodiesel From Alternative Oilseed Feedstocks: Production and Properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid methyl esters were prepared and evaluated as potential biodiesel fuels from several alternative oilseed feedstocks, which included camelina (Camelina sativa L.), coriander (Coriandrum sativum L.), field mustard (Brassica juncea L.), field pennycress (Thlaspi arvense L.), and meadowfoam (L...

  19. Classification of specialty seed meals from NIR reflectance spectra

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near infrared reflectance spectroscopy was used to identify alternative seed meals proposed for food and feed formulations. Spectra were collected from cold pressed Camelina (Camelina sativa), Coriander (Coriandrum sativum), and Pennycress (Thlaspi arvense) meals. Additional spectra were collected ...

  20. ls phytoextraction a suitable green treatment for metal-contaminated Huguet S. 1,2,3, Sarret G.14 Bert V.3 * , Isaure M.P.l,

    E-print Network

    Paris-Sud XI, Université de

    hyperaccumulating plants on contaminated sédiments [3, 4, 5, 6]. Plants called hyperaccumulators are definedls phytoextraction a suitable green treatment for metal-contaminated sédiments? Huguet S. 1 for the réclamation of thèse polluted sédiments. To our knowledge, phytoextraction with hyperaccumulating plants has

  1. Plant and rhizosphere processes involved in phytoremediation of metal-contaminated soils

    Microsoft Academic Search

    S. P. McGrath; F. J. Zhao; E. Lombi

    2001-01-01

    This paper reviews the recent advances in understanding of metal removal from contaminated soils, using either hyperaccumulator plants, or high biomass crop species after soil treatment with chelating compounds. Progress has been made at the physiology and molecular level regarding Zn and Ni uptake and translocation in some hyperaccumulators. It is also known that natural hyperaccumulators do not use rhizosphere

  2. Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of an integrated strategy for the remediation of soil co-contaminated by heavy metals and persistent organic pollutants is a major research priority for the decontamination of soil slated for use in agricultural production. The objective of this study was to develop a bioremediation ...

  3. Geogenic Nickel Speciation in Serpentine Soils and Its Relationship to Nickel Uptake in Hyperaccumulator Plants. Tuesday, November 3, 2009: 3:00 PM

    E-print Network

    Sparks, Donald L.

    Geogenic Nickel Speciation in Serpentine Soils and Its Relationship to Nickel Uptake to serpentine soils, which have geogenically augmented nickel concentrations. Nickel concentration increases in serpentine soils because geochemical weathering processes alter and proportionally increase its concentration

  4. Interactive effects of pH, arsenic and phosphorus on uptake of As and P and growth of the arsenic hyperaccumulator Pteris

    E-print Network

    Ma, Lena

    of phytoremediation technique to clean up As-polluted sites including groundwater is gaining attention due operation of phytoremediation is determined by two stipulations, i.e., identification of plants with great potentially be used for phytoremediation of As-contaminated sites. For a given plant species, As uptake

  5. Removal of Ni(II) and Cu(II) ions using native and acid treated Ni-hyperaccumulator plant Alyssum discolor from Turkish serpentine soil.

    PubMed

    Bayramoglu, Gulay; Arica, M Yakup; Adiguzel, Nezaket

    2012-09-01

    Alyssum discolor biomass was collected from serpentine soil and was used for removal of metal ions. The plant species grown on serpentine soils are known to be rich with metals ions and thus have more capability for accumulating heavy metals. Native and acid-treated biomass of A. discolor (A. discolor) were utilized for the removal of Ni(II) and Cu(II) ions from aqueous solutions. The effects of contact time, initial concentration, and pH on the biosorption of Ni(II) and Cu(II) ions were investigated. Biosorption equilibrium was established in about 60 min. The surface properties of the biomass preparations were varied with pH, and the maximum amounts of Ni(II) and Cu(II) ions on both A. discolor biomass preparations were adsorbed at pH 5.0. The maximum biosorption capacities of the native, and acid-treated biomass preparations for Ni(II) were 13.1 and 34.7 mgg(-1) and for Cu(II) 6.15 and 17.8 mgg(-1) dry biomass, respectively. The biosorption of Ni(II) and Cu(II) ions from single and binary component systems can be successfully described by Langmuir and Freundlich isotherms. When the heavy metal ions were in competition, the amounts of biosorbed metal ions on the acid treated plant biomass were found to be 0.542 mmolg(-1) for Ni(II) and 0.162 mmolg(-1) for Cu(II), the A. discolor biomass was significantly selective for Ni(II) ions. The information gained from these studies was expected to indicate whether the native, and acid-treated forms can have the potential to be used for the removal and recovery of Ni(II) ions from wastewaters. PMID:22608134

  6. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1995--June 20, 1995

    SciTech Connect

    Kochian, L.

    1995-12-01

    The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.

  7. IN SITU SPECIATION OF COBALT IN NI/CO HYPERACCUMULATOR ALYSSUM MURALE USING BULK AND MICRO-FOCUSED X-RAY ABSORPTION SPECTROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The long-term fate of trace metals in contaminated soil systems is a significant issue in environmental chemistry. Unique plant species have evolved an ability to accumulate large quantities of trace metals in their harvestable biomass, and thereby offer a sustainable method for treatment of metal c...

  8. Bioaccessibility versus Bioavailability of Essential (Cu, Fe, Mn, and Zn) and Toxic (Pb) Elements from Phyto Hyperaccumulator Pistia stratiotes: Potential Risk of Dietary Intake.

    PubMed

    ?adková, Zuzana; Száková, Ji?ina; Miholová, Daniela; Horáková, Barbora; Kopecký, Old?ich; K?ivská, Daniela; Langrová, Iva; Tlustoš, Pavel

    2015-03-01

    Aquatic weeds are widely used as animal feed in developing countries. However, information about element bioavailability from these plants is lacking. A combination of an in vitro method [physiologically based extraction test (PBET)] and an in vivo feeding trial was used in this study to investigate potential element bioaccessibility and estimated bioavailability of Pistia stratiotes (PS). Cu, Fe, Mn, Zn, and Pb concentrations in PS biomass, artificial gastrointestinal fluids, and rat tissues were determined using atomic absorption spectrometry with electrothermal atomization and inductively coupled plasma-atomic emission spectrometry. PS exhibited elevated Fe, Mn, and Pb levels. The PBET revealed high bioaccessibility of all monitored elements from PS biomass. The results of the in vivo trial were inconsistent with those of the PBET, because animals fed PS exhibited low levels of essential elements in the tissues. The consumption of a PS-supplemented diet significantly decreased total Fe levels and increased the total level of accumulation of Pb in exposed animals. Significantly reduced amounts of essential elements in the intestinal walls indicated a potential disruption in nutrient gastrointestinal absorption in animals fed PS. PMID:25664561

  9. Comparative cDNA-AFLP analysis of Cd-tolerant and -sensitive genotypes derived from crosses between the Cd hyperaccumulator Arabidopsis halleri and Arabidopsis lyrata ssp. petraea

    Microsoft Academic Search

    Adrian Radu Craciun; Mikael Courbot; Fabienne Bourgis; Pietrino Salis; Pierre Saumitou-Laprade; Nathalie Verbruggen

    2006-01-01

    Cadmium (Cd) tolerance seems to be a constitutive species-level trait in Arabidopsis halleri. In order to identify genes potentially implicated in Cd tolerance, a backcross (BC1) segregating population was produced from crosses between A. halleri ssp. halleri and its closest non-tolerant relative A. lyrata ssp. petraea. The most sensitive and tolerant genotypes of the BC1 were analysed on a transcriptome-wide

  10. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly progress report, July 1, 1996--September 30, 1996

    SciTech Connect

    Kochian, L. [Cornell Univ., Ithaca, NY (United States)

    1997-05-01

    Potential for phytoremediation of an aged radiocesium-contaminated soil from Brookhaven National Laboratory was investigated in three phases: (1) hydroponic screening for plant species capable of accumulating elevated levels of cesium in shoots, (2) amending contaminated soil to enhance {sup 137}Cs bioavailability, and (3) phytoextracting radiocesium with plant roots and its removal in harvested shoots. The bioaccumulation ratio of Cs in shoots of hydroponically grown plants ranged between 38 and 165. From solution, dicot species accumulated 2- to 4-fold more cesium in shoots than grasses. The effect of several chemical compounds on {sup 137}Cs desorption from the contaminated soil was investigated. Ammonium salts were the most effective at desorbing Cs from contaminated soil, but only 25% of radiocesium could be desorbed. Although release of radiocesium from the soil was concentration-dependent, this effect appeared to level off above 0.2 M ammonium in solution. In a pot study, from the soil contaminated with 400 pCi g{sup -1} soil, the greatest amount of {sup 137}Cs, 140 pCi, was removed in shoots of cabbage (Brassica oleracea var. capitata). {sup 137}Cs accumulation in shoots was significantly increased by the addition of 40 NH{sub 4}NO{sub 3} kg{sup -1} soil. Increasing NH{sub 4}NO{sub 3} application from 40 to 80 mmoles kg{sup -1} soil did not further increase radiocesium phytoextraction. The ability to accumulate radiocesium from soil in shoots was significantly different among species tested. This ability increased in order: reed Canary grass (Phalaris arundinacea) < Indian mustard (Brassica juncea) < tepary bean (Phaseolus acutifolius) < cabbage.

  11. The current status of the elemental defense hypothesis in relation to pathogens

    PubMed Central

    Hörger, Anja C.; Fones, Helen N.; Preston, Gail M.

    2013-01-01

    Metal hyperaccumulating plants are able to accumulate exceptionally high concentrations of metals, such as zinc, nickel, or cadmium, in their aerial tissues. These metals reach concentrations that would be toxic to most other plant species. This trait has evolved multiple times independently in the plant kingdom. Recent studies have provided new insight into the ecological and evolutionary significance of this trait, by showing that some metal hyperaccumulating plants can use high concentrations of accumulated metals to defend themselves against attack by pathogenic microorganisms and herbivores. Here, we review the evidence that metal hyperaccumulation acts as a defensive trait in plants, with particular emphasis on plant–pathogen interactions. We discuss the mechanisms by which defense against pathogens might have driven the evolution of metal hyperaccumulation, including the interaction of this trait with other forms of defense. In particular, we consider how physiological adaptations and fitness costs associated with metal hyperaccumulation could have resulted in trade-offs between metal hyperaccumulation and other defenses. Drawing on current understanding of the population ecology of metal hyperaccumulator plants, we consider the conditions that might have been necessary for metal hyperaccumulation to be selected as a defensive trait, and discuss the likelihood that these were fulfilled. Based on these conditions, we propose a possible scenario for the evolution of metal hyperaccumulation, in which selective pressure for resistance to pathogens or herbivores, combined with gene flow from non-metallicolous populations, increases the likelihood that the metal hyperaccumulating trait becomes established in plant populations. PMID:24137169

  12. REGULAR ARTICLE Interaction of nickel and manganese in accumulation

    E-print Network

    Sparks, Donald L.

    . Hyperaccumulator. Manganese localization . Nickel localization . Phytoremediation . trichomes Introduction More 1992). Our research consortium has developed commercially feasible phytoremediation and phyto- mining

  13. Assessing the Bioavailability of Ni in Smelter Contaminated Soils. (S11-everhart242852-oral)

    E-print Network

    Sparks, Donald L.

    . Avena sativa, a nonhyperaccumulator, and Alyssum murale, a hyperaccumulator plant species, were grown when bioavailability decreased which was not the case for Avena sativa. The Ni bacterial biosensor

  14. Elemental selenium particles at nano-size (Nano-Se) are more toxic to Medaka ( Oryzias latipes) as a consequence of hyper-accumulation of selenium: A comparison with sodium selenite

    Microsoft Academic Search

    Hongcheng Li; Jinsong Zhang; Thanh Wang; Wenru Luo; Qunfang Zhou; Guibin Jiang

    2008-01-01

    Recent studies have shown that elemental selenium particles at nano-size (Nano-Se) exhibited comparable bioavailability and less toxicity in mice and rats when compared to sodium selenite, selenomethinine and methylselenocysteine. However, little is known about the toxicity profile of Nano-Se in aquatic animals. In the present study, toxicities of Nano-Se and selenite in selenium-sufficient Medaka fish were compared. Selenium bioaccumulation and

  15. Effects of inoculation of a plant growth promoting rhizobacterium Burkholderia sp. D54 on plant growth and metal uptake by a hyperaccumulator Sedum alfredii Hance grown on multiple metal contaminated soil

    Microsoft Academic Search

    Junkang Guo; Shirong Tang; Xuehai Ju; Yongzhen Ding; Shangqiang Liao; Ningning Song

    Batch experiments were designed to characterize a multiple metal resistant bacterium Burkholderia sp. D54 isolated from metal contaminated soils in the Dabaoshan Mine in South China, and a follow-up experiment was conducted\\u000a to investigate the effects of inoculating the isolate on plant growth and metal uptake by Sedum alfredii Hance grown on soils collected from a heavily contaminated paddy field

  16. 490 www.newphytologist.org To investigate whether selenium (Se) accumulation in plants provides a chemical

    E-print Network

    protection, Orthoptera, selenium (Se) hyperaccumulator, Stanleya pinnata, toxicity. New Phytologist (2007 and performance of a mix of orthopteran species were investigated. · The selenium hyperaccumulator Stanleya pinnata and accumulator Brassica juncea were used in herbivory studies in the laboratory, and S. pinnata

  17. Selenium accumulation in flowers and its effects on pollination

    E-print Network

    , floral visitor, hyperaccumulator, pollen germination, selenium (Se), Stanleya pinnata. Summary · Selenium­pollinator interactions. · Floral Se distribution and speciation were compared in Stanleya pinnata, an Se hyperaccumulator. · Stanleya pinnata preferentially allocated Se to flowers, as nontoxic methyl-sel- enocysteine (Me

  18. Overexpression of Selenocysteine Methyltransferase in Arabidopsis and Indian Mustard Increases Selenium Tolerance and Accumulation1

    Microsoft Academic Search

    Danika L. LeDuc; S. Tarun; Maria Montes-Bayon; Juris Meija; Michele F. Malit

    2004-01-01

    A major goal of phytoremediation is to transform fast-growing plants with genes from plant species that hyperaccumulate toxic trace elements. We overexpressed the gene encoding selenocysteine methyltransferase (SMT) from the selenium (Se) hyperaccumulator Astragalus bisulcatus in Arabidopsis and Indian mustard (Brassica juncea). SMT detoxifies selenocysteine by methylating it to methylselenocysteine, a nonprotein amino acid, thereby diminishing the toxic misincorporation of

  19. Trends in literature on new oilseed crops and related species: Seeking evidence of increasing or waning interest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bibliographic records on eight new crop species Camelina, Crambe, Cuphea, Physaria, Limnanthes, Stokesia, Thlaspi, and Vernonia from Agricola, CAB Abstracts, Scopus, and Web of Science were analyzed for historical and recent trends in the areas of research, author distribution, and quantity and impa...

  20. Extraction of proteins from pennycress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress (Thlaspi arvense L.)has recently been found to have value as a source of biodiesel. Not only does it provide a high yield of quality oil, but perhaps more importantly, it can be planted after the harvest of traditional crops. It will grow through the winter (on days warmer than 0 C) and...

  1. Seed oil development of pennycress under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress (Thlaspi sp) has been targeted as a potential oilseed for the biofuels industry. Its seeds contain ~36% oil, where erucic acid is the major fatty acid presented with 38.1%. Additionally, the physical proprieties of the methyl esters are in the range to satisfy the needs of the biodiesel m...

  2. Comparison of the emergence of three Brassicaceae species of different origins grown in Spain and USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thlaspi arvense, Camelina sativa, C. microcarpa and Neslia paniculata are four Brassicaceae family species that are becoming rare in North-Eastern Spain. Conversely, both T. arvense and C. sativa are being investigated as oilseed crops in North America for industrial/biofuel purposes. C. microcarpa ...

  3. This journal is c The Royal Society of Chemistry 2013 Metallomics Cite this: DOI: 10.1039/c3mt00215b

    E-print Network

    have identified how copper is bound to cell walls of intact roots of native Thlaspi arvense by combining synchrotron X-ray fluorescence and absorption techniques (XANES and EXAFS) at the nano-, micro-, and bulk scales. The plants grew naturally in sediment in a stormwater runoff basin at copper

  4. Lubrication properties of new crop oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oils from new crops such as lesquerella (Lesquerella fendleri), field pennycress (Thlaspi arvense L.), meadowfoam (Limnanthes alba L.), and cuphea PSR-23 (Cuphea viscosissima × Cuphea lanceolata) were investigated and compared with vegetable oils from commodity crops such as castor, corn, and soybea...

  5. Synthesis and physical properties of pennycress estolide 2-ethylhexyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennycress (Thlaspi arvense L.) is a new crop that is currently being developed as an off-season rotation crop between annual corn and soybean production in Central Illinois by USDA-NCAUR. This rotation scheme may offer distinct advantages to farmers by providing additional farm income from an other...

  6. Comparison of arsenic accumulation in 18 fern species and four Pteris vittata Mrittunjai Srivastava 1

    E-print Network

    Ma, Lena

    Comparison of arsenic accumulation in 18 fern species and four Pteris vittata accessions Mrittunjai 2009 Keywords: Pteris Arsenic Hyperaccumulation Fern Speciation a b s t r a c t This study evaluated

  7. American Journal of Botany 101(5): 830839, 2014; http://www.amjbot.org/ 2014 Botanical Society of America American Journal of Botany 101(5): 830839. 2014.

    E-print Network

    830 American Journal of Botany 101(5): 830­839, 2014; http://www.amjbot.org/ © 2014 Botanical Society of America American Journal of Botany 101(5): 830­839. 2014. Hyperaccumulation is the intriguing

  8. American Journal of Botany 99(12): 19301941, 2012; http://www.amjbot.org/ 2012 Botanical Society of America American Journal of Botany 99(12): 19301941. 2012.

    E-print Network

    1930 American Journal of Botany 99(12): 1930­1941, 2012; http://www.amjbot.org/ © 2012 Botanical Society of America American Journal of Botany 99(12): 1930­1941. 2012. Several hyperaccumulator taxa

  9. American Journal of Botany 96(6): 10751085. 2009. Certain specialized plant species growing on naturally en-

    E-print Network

    , and its impacts on the local ecosystem. In the western United States, the genera Astragalus and Stan- leya are known to hyperaccumulate Se in their shoot tissues, up to 1% for Astragalus bisulcatus and 0

  10. Optimisation de la phytoextraction : caractrisation et slection de bactries PGPB associes une plante hyperaccumulatrice de Zn et

    E-print Network

    Paris-Sud XI, Université de

    plants for the treatment of contaminated sites. Among these, phytoextraction based on hyperaccumulator, a microbial-assisted plant technology usable for the treatment of contaminated sites, exploits natural plante hyperaccumulatrice de Zn et Cd : Arabidopsis halleri Phytoextraction optimization

  11. Copper and Zinc Phytoremediation by Native Herbaceous and Grass Species

    E-print Network

    Polly, David

    Copper and Zinc Phytoremediation by Native Herbaceous and Grass Species Colonized on Remediated. of Geological Sciences #12;Phytoremediation Definition: The use of vascular plants to improve environmental contaminated soils Effective phytoremediation relies on hyperaccumulators Excluders show greater tolerance

  12. Current Biology 16, 21812192, November 21, 2006 2006 Elsevier Ltd All rights reserved DOI 10.1016/j.cub.2006.09.015 Selenium-Tolerant

    E-print Network

    (Stanleya pinnata) protects it from caterpillar herbivory because of deterrence and toxicity. In its natural on the same site [1]. Selenium (Se)-hyperaccumulating plants such as Stanleya pinnata (Brassicaceae

  13. www.newphytologist.org 1 Blackwell Publishing Ltd

    E-print Network

    Se hyperaccumulator species (Astragalus bisulca- tus and Stanleya pinnata) with nonhyperaccumulators microcarpa, Descurainia pinnata, elemental defense, Helianthus pumilus, Medicago sativa, Stanleya pinnata (Camelina microcarpa, Astragalus americanus, Descurainia pinnata, Medicago sativa, and Helianthus pumilus

  14. Chelate-Enhanced Phytoremediation of Soils Polluted with Heavy Metals

    Microsoft Academic Search

    I. Alkorta; J. Hernández-Allica; J. M. Becerril; I. Amezaga; I. Albizu; M. Onaindia; C. Garbisu

    2004-01-01

    In general, hyperaccumulators are low biomass, slow-growing plants. High biomass non-hyperaccumulator plants by themselves are not a valid alternative for phytoextraction as they also have many limitations, such as small root uptake and little root-to-shoot translocation. In this context, chemically-induced phytoextraction (based on the fact that the application of certain chemicals, mostly chelating agents, to the soil significantly enhances metal

  15. Metallophytes—a view from the rhizosphere

    Microsoft Academic Search

    Élan R. Alford; Elizabeth A. H. Pilon-Smits; Mark W. Paschke

    2010-01-01

    Some plants hyperaccumulate metals or metalloids to levels several orders of magnitude higher than other species. This intriguing\\u000a phenomenon has received considerable attention in the past decade. While research has mostly focused on the above-ground organs,\\u000a roots are the sole access point to below-ground trace elements and as such they play a vital role in hyperaccumulation. Here\\u000a we highlight the

  16. Overexpression of Selenocysteine Methyltransferase in Arabidopsis and Indian Mustard Increases Selenium Tolerance and Accumulation1

    Microsoft Academic Search

    Danika L. LeDuc; Alice S. Tarun; Maria Montes-Bayon; Juris Meija; Michele F. Malit; Carol P. Wu; Manal AbdelSamie; Chih-Yuan Chiang; Abderrhamane Tagmount; Bernhard Neuhierl; August Bock; Joseph A. Caruso; Norman Terry

    2003-01-01

    A major goal of phytoremediation is to transform fast-growing plants with genes from plant species that hyperaccumulate toxic trace elements. We overexpressed the gene encoding seleno-cysteine (Cys) methyltransferase (SMT) from the selenium (Se) hyperaccumulator, Astragalus bisulcatus, in Arabidopsis and Indian mustard (Brassica juncea). SMT detoxifies seleno- cysteine by methylating it to methylseleno-Cys, a nonprotein amino acid, thereby diminishing the toxic

  17. Segetal vegetation of Central Yakutia

    Microsoft Academic Search

    B. M. Mirkin; N. P. Slepcova; K. E. Kononov

    1988-01-01

    Seven associations of segetal vegetation are distinguished for the vast arable lands of Central Yakutia. Low species richness\\u000a and the prevalence of annual weeds are the main features of these communities. Only two dominant speciesSphallerocarpus gracilis andSaussurea amara represent Asian types of areals. Other dominantsFallopia convolvulus, Elytrigia repens, Chenopodium album, Brassica campestris, Lappula squarrosa, Scutellaria galericulata,\\u000a Thlaspi arvense, Avena fatua

  18. Variation in Heavy Metal Accumulation and Genetic Diversity at a Regional Scale Among Metallicolous and Non-Metallicolous Populations of the Facultative Metallophyte Biscutella laevigata subsp. laevigata.

    PubMed

    Poš?i?, Filip; Fellet, Guido; Vischi, Massimo; Casolo, Valentino; Schat, Henk; Marchiol, Luca

    2015-01-01

    Biscutella laevigata is a facultative metallophyte, with populations on non-metalliferous and metalliferous soils. Some of its metallicolous populations have been shown to hyperaccumulate thallium or lead in nature. Only Tl hyperaccumulation has been experimentally confirmed. We aimed to compare the patterns of metal (hyper)accumulation and genetic diversity among populations of B. laevigata subsp. laevigata in NE Italy. None of the populations exhibited foliar hyperaccumulation of Cu, Zn, or Pb. The root-to-shoot accumulation rates for these metals were unchanged or decreased rather than enhanced in the metallicolous populations, in comparison with the non-metallicolous ones. Hyperaccumulation of Tl was confined to the population of the Cave del Predil mine. This population was genetically very distinct from the others, as demonstrated by AFLP-based cluster analysis. The two other mine populations did not surpass the threshold for Tl hyperaccumulation, but showed enhanced foliar Tl concentrations and root-to-shoot translocation rates, in comparison with the non-metallicolous populations. Genetic analysis suggested that adaptation to metalliferous soil must have been independently evolved in the metallicolous populations. PMID:25495937

  19. Classification and identification of metal-accumulating plant species by cluster analysis.

    PubMed

    Yang, Wenhao; Li, He; Zhang, Taoxiang; Sen, Lin; Ni, Wuzhong

    2014-09-01

    Identification and classification of metal-accumulating plant species is essential for phytoextraction. Cluster analysis is used for classifying individuals based on measured characteristics. In this study, classification of plant species for metal accumulation was conducted using cluster analysis based on a practical survey. Forty plant samples belonging to 21 species were collected from an ancient silver-mining site. Five groups such as hyperaccumulator, potential hyperaccumulator, accumulator, potential accumulator, and normal accumulating plant were graded. For Cd accumulation, the ancient silver-mining ecotype of Sedum alfredii was treated as a Cd hyperaccumulator, and the others were normal Cd-accumulating plants. For Zn accumulation, S. alfredii was considered as a potential Zn hyperaccumulator, Conyza canadensis and Artemisia lavandulaefolia were Zn accumulators, and the others were normal Zn-accumulating plants. For Pb accumulation, S. alfredii and Elatostema lineolatum were potential Pb hyperaccumulators, Rubus hunanensis, Ajuga decumbens, and Erigeron annuus were Pb accumulators, C. canadensis and A. lavandulaefolia were potential Pb accumulators, and the others were normal Pb-accumulating plants. Plant species with the potential for phytoextraction were identified such as S. alfredii for Cd and Zn, C. canadensis and A. lavandulaefolia for Zn and Pb, and E. lineolatum, R. hunanensis, A. decumbens, and E. annuus for Pb. Cluster analysis is effective in the classification of plant species for metal accumulation and identification of potential species for phytoextraction. PMID:24888623

  20. The potential for heavy metal decontamination

    SciTech Connect

    Baker, A.J.M. [Univ. of Sheffield (United Kingdom); McGrath, S.P.; Sidoli, C.M.D. [AFRC Institute of Arable Crops Research, Harpenden (United Kingdom); Reeves, R.D. [Massey Univ., Palmerston North (New Zealand)

    1996-12-31

    Preliminary trials to assess the ability of plant species to extract metals are presented. A range of zinc and nickel hyperaccumulator plants from the Brassicaceae family, collected from diverse populations in Europe, were grown on plots along with nonaccumulating crop plants from the same family. Extraction efficiencies and the number of croppings required to reduce the total zinc in the soil to a concentration of 300 mg/kg are tabulated. Zinc accumulation remained high over a wide range of soil metal concentration. However, the concentration of nickel in the hyperaccumulators increased in accordance with increasing total nickel concentrations in the soil. Calculations suggest that there is an excellent potential for using hyperaccumulator species to remove metals from the rhizosphere where remediation can be considered over a period of years and multiple cropping is a viable option.

  1. Overexpression of Selenocysteine Methyltransferase in Arabidopsis and Indian Mustard Increases Selenium Tolerance and Accumulation1

    PubMed Central

    LeDuc, Danika L.; Tarun, Alice S.; Montes-Bayon, Maria; Meija, Juris; Malit, Michele F.; Wu, Carol P.; AbdelSamie, Manal; Chiang, Chih-Yuan; Tagmount, Abderrhamane; deSouza, Mark; Neuhierl, Bernhard; Böck, August; Caruso, Joseph; Terry, Norman

    2004-01-01

    A major goal of phytoremediation is to transform fast-growing plants with genes from plant species that hyperaccumulate toxic trace elements. We overexpressed the gene encoding selenocysteine methyltransferase (SMT) from the selenium (Se) hyperaccumulator Astragalus bisulcatus in Arabidopsis and Indian mustard (Brassica juncea). SMT detoxifies selenocysteine by methylating it to methylselenocysteine, a nonprotein amino acid, thereby diminishing the toxic misincorporation of Se into protein. Our Indian mustard transgenic plants accumulated more Se in the form of methylselenocysteine than the wild type. SMT transgenic seedlings tolerated Se, particularly selenite, significantly better than the wild type, producing 3- to 7-fold greater biomass and 3-fold longer root lengths. Moreover, SMT plants had significantly increased Se accumulation and volatilization. This is the first study, to our knowledge, in which a fast-growing plant was genetically engineered to overexpress a gene from a hyperaccumulator in order to increase phytoremediation potential. PMID:14671009

  2. Overexpression of selenocysteine methyltransferase in Arabidopsis and Indian mustard increases selenium tolerance and accumulation.

    PubMed

    LeDuc, Danika L; Tarun, Alice S; Montes-Bayon, Maria; Meija, Juris; Malit, Michele F; Wu, Carol P; AbdelSamie, Manal; Chiang, Chih-Yuan; Tagmount, Abderrhamane; deSouza, Mark; Neuhierl, Bernhard; Böck, August; Caruso, Joseph; Terry, Norman

    2004-05-01

    A major goal of phytoremediation is to transform fast-growing plants with genes from plant species that hyperaccumulate toxic trace elements. We overexpressed the gene encoding selenocysteine methyltransferase (SMT) from the selenium (Se) hyperaccumulator Astragalus bisulcatus in Arabidopsis and Indian mustard (Brassica juncea). SMT detoxifies selenocysteine by methylating it to methylselenocysteine, a nonprotein amino acid, thereby diminishing the toxic misincorporation of Se into protein. Our Indian mustard transgenic plants accumulated more Se in the form of methylselenocysteine than the wild type. SMT transgenic seedlings tolerated Se, particularly selenite, significantly better than the wild type, producing 3- to 7-fold greater biomass and 3-fold longer root lengths. Moreover, SMT plants had significantly increased Se accumulation and volatilization. This is the first study, to our knowledge, in which a fast-growing plant was genetically engineered to overexpress a gene from a hyperaccumulator in order to increase phytoremediation potential. PMID:14671009

  3. Characterization of selenium and sulfur accumulation across the genus Stanleya (Brassicaceae): A field survey and common-garden experiment.

    PubMed

    Cappa, Jennifer J; Cappa, Patrick J; El Mehdawi, Ali F; McAleer, Jenna M; Simmons, Mark P; Pilon-Smits, Elizabeth A H

    2014-04-21

    • Premise of study: Selenium (Se) hyperaccumulation, the capacity to concentrate the toxic element Se above 1000 mg·kg(-1)·dry mass, is found in relatively few taxa native to seleniferous soils. While Se hyperaccumulation has been shown to likely be an adaptation that protects plants from herbivory, its evolutionary history remains unstudied. Stanleya (Brassicaceae) is a small genus comprising seven species endemic to the western United States. Stanleya pinnata is a hyperaccumulator of selenium (Se). In this study we investigated to what extent other Stanleya taxa accumulate Se both in the field and a greenhouse setting on seleniferous soil.• Methods: We collected multiple populations of six of the seven species and all four varieties of S. pinnata. We tested leaves, fruit, and soil for in situ Se and sulfur (S) concentrations. The seeds collected in the field were used for a common garden study in a greenhouse.• Key results: We found that S. pinnata var. pinnata is the only hyperaccumulator of Se. Within S. pinnata var. pinnata, we found a geographic pattern related to Se hyperaccumulation where the highest accumulating populations are found on the eastern side of the continental divide. We also found differences in genome size within the S. pinnata species complex.• Conclusions: The S. pinnata species complex has a range of physiological properties making it an attractive system to study the evolution of Se hyperaccumulation. Beyond the basic scientific value of understanding the evolution of this fascinating trait, we can potentially use S. pinnata or its genes for environmental cleanup and/or nutrient-enhanced dietary material. PMID:24752889

  4. Effects of Cadmium on Nickel Tolerance and Accumulation in Alyssum species and Cabbage Grown in Nutrient Solution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nickel phytoextraction using hyperaccumulator plant species to accumulate Ni from mineralized and contaminated soils rich in Ni is an emerging technology. Serpentinite derived soils which contain Ni ore value have a very low ratio of Ca:Mg among soils due the nature of the parent rock. In crop plant...

  5. NiO(s) (Bunsenite) is not Available to Alyssum species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AIMS: To determine if the Ni-hyperaccumulator Alyssum corsicum can absorb Ni from the kinetically inert crystalline mineral NiO(s) (bunsenite). METHODS: A. corsicum and A. montanum plants were grown for 30 days in a serpentine Hoagland solution. NiO was provided at 0 or 0.1 g L-1 (1.34 mmol L-1) ...

  6. Mechanisms of lichen resistance to metallic pollution

    Microsoft Academic Search

    C. Sarret; Alain Manceau; L. Eybert-Berard; D. Cuny; C. van Haluwyn; S. Deruelle; J. L. Hazemann; J. J. Menthonnex; Y. Soldo

    1998-01-01

    Some lichens have a unique ability to grow in heavily contaminated areas due to the development of adaptative mechanisms allowing a high tolerance to metals. Here the authors report on the chemical forms of Pb and Zn in the metal hyperaccumulator Diploschistes muscorum and of Pb in the metal tolerant lichen Xanthoria parietina. The speciation of Zn and Pb has

  7. Plant and Soil 258: 919, 2004. 2004 Kluwer Academic Publishers. Printed in the Netherlands.

    E-print Network

    Ma, Lena

    Abstract This study compared the roles of root exudates collected from two fern species, the As hyperaccumulating Chinese Brake fern (Pteris vittata L.) and the As-sensitive Boston fern (Nephrolepis exaltata L arsenate)-contaminated soil as well as plant As accumulation. Chinese Brake fern exuded 2 times more

  8. AREA 5 WASTE DISPOSAL RESEARCH ARTICLE Biomass reduction and arsenic transformation

    E-print Network

    Ma, Lena

    and arsenic transformation during com- posting As-rich biomass of hyperaccumulator Chinese brake fern (Pteris vittata L.). Materials and methods High-As fern biomass containing 4,600 mg As kg-1 was composted for 120 reduced the fern biomass by 38%, comparable to 35% reduction of the low-As fern biomass containing 12 mg

  9. Research article Characterization of phytase from three ferns with differing arsenic tolerance

    E-print Network

    Ma, Lena

    Research article Characterization of phytase from three ferns with differing arsenic tolerance S-hyperaccumulator Pteris vittata were determined. Two arsenic-sensitive ferns (Pteris ensiformis and Nephrolepis exaltata) were included for comparison purpose. Fern phytase was extracted with TriseHCl buffer (pH 7.6) followed

  10. ontamination of soils with arsenic, which is both toxic and carcinogenic,

    E-print Network

    Ma, Lena

    have discovered that the fern Pteris vittata (brake fern) is extremely efficient in extracting arsenic, is the first known arsenic hyperaccumulator as well as the first fern found to function as a hyper- accumulator. We found brake fern growing on a site in Central Florida contaminated with chromated copper arsenate

  11. Expression of an "Arabidopsis" Ca(2+)/H(+) antiporter CAX1 variant in petunia enhances cadmium tolerance and accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoremediation is a cost-effective and minimally invasive technology to cleanse soils contaminated with heavy metals. However, few plant species are suitable for phytoremediation of metals such as cadmium (Cd). Genetic engineering offers a powerful tool to generate plants that can hyperaccumulate ...

  12. Remediation of Heavy Metal Contaminated Soils: Phytoremediation as a Potentially Promising Clean-Up Technology

    Microsoft Academic Search

    Ana P. G. C. Marques; António O. S. S. Rangel; Paula M. L. Castro

    2009-01-01

    Increased soil pollution with heavy metals due to various human and natural activities has led to a growing need to address environmental contamination. Some remediation technologies have been developed to treat contaminated soil, but a biology-based technology, phytoremediation, is emerging. Phytoremediation includes phytovolatilization, phytostabilization, and phytoextraction using hyperaccumulator species or a chelate-enhancement strategy. To enhance phytoremediation as a viable strategy,

  13. Chemical Mutagenesis—A Promising Technique to Increase Metal Concentration and Extraction in Sunflowers

    Microsoft Academic Search

    Erika Nehnevajova; Rolf Herzig; Guido Federer; Karl-Hans Erismann; Jean-Paul Schwitzguébel

    2007-01-01

    Since most of the metal-hyperaccumulating wild plants only produce very low biomass and many high-yielding crops accumulate only moderate amounts of metals, the current research is mainly focused on overcoming these limitations and the optimization of metal phytoextraction. The main goal of the present study was the improvement of metal concentration and extraction properties of Helianthus annuus L by chemical

  14. Author's personal copy Journal of Hazardous Materials 185 (2011) 983989

    E-print Network

    Ma, Lena

    .elsevier.com/locate/jhazmat Phytoremediation of arsenic-contaminated groundwater using arsenic hyperaccumulator Pteris vittata L.: Effects refill a b s t r a c t A large-scale hydroponic system to phytoremediate arsenic-contaminated groundwater containing 600 L of arsenic-contaminated groundwater and 32 ferns. During Cycle 1 and with initial As of 140

  15. Journal of Hazardous Materials 180 (2010) 662667 Contents lists available at ScienceDirect

    E-print Network

    Ma, Lena

    Hyperaccumulation Groundwater a b s t r a c t Optimization of arsenic uptake by Pteris vittata may reduce the remediation time and cost of arsenic- contaminated groundwater. This greenhouse experiment evaluated) on the effectiveness of arsenic removal using 18 L of contaminated groundwater per plant. Arsenic

  16. Metabolic adaptations to arsenic-induced oxidative stress in Pteris vittata L and Pteris ensiformis L

    E-print Network

    Ma, Lena

    leads to groundwater contamination and arsenic toxicity in plants, humans and animals. RemediationMetabolic adaptations to arsenic-induced oxidative stress in Pteris vittata L and Pteris ensiformis the metabolic adaptations of Pteris vittata L, an arsenic hyperaccumulator, under arsenic stress as compared

  17. Effects of arsenic on concentration and distribution of nutrients in the fronds of the arsenic

    E-print Network

    Ma, Lena

    , it is unclear how As hyperaccumulation influences nutrient uptake by this plant. P. vittata fern was grown be used as the threshold value for normal growth of P. vittata. Potassium may function as a counter elevated due to anthropogenic activ- ities such as ore mining, coal combustion, and use of As

  18. J. PHYS. IV FRANCE 7 (1997) Colloque C2, Supplement au Journal de Physique 111d'avril 1997

    E-print Network

    Paris-Sud XI, Université de

    and the efficacy of environmentalremediation and restoration activities and for bioremediation of contaminated of an environmentalrestoration strategy. There are a number of organisms that can function as effective biomonitors.Wolflabrasiliensis,Lemna minor (duckweed),and Azolla caroliniana (water fern) have been demonstrated to be hyperaccumulators

  19. Assessment of Bioaccumulation of Heavy Metal by Pteris Vittata L. Growing in the Vicinity of Fly Ash

    Microsoft Academic Search

    Alka Kumari; Brij Lal; Yogesh B. Pakade; Piar Chand

    2011-01-01

    Pteris vittata L. subsp. vittata, a potential arsenic hyperaccumulator fern, growing naturally in the vicinity of fly ash was analyzed for the concentration of nine heavy metals (Fe, Cu, Zn Ni, Al, Cr, Pb, Si, and As) from five different sites around of Kanti Thermal Power Station at Muzaffarpur in Bihar State, India. Metal accumulation in P. vittata was correlated

  20. EFFECTIVENESS OF METALMETAL AND METALORGANIC COMPOUND COMBINATIONS

    E-print Network

    Behmer, Spencer T.

    - accumulators. The defense hypothesis suggests that these plants may be defended against folivore attack the hypothesis that herbivore defense may have led to the evolution of metal hyperaccumulation by increas- ing the preexisting defensive effects of metals at accumulator levels in plants. Key Words --Accumulation, alkaloids

  1. 2009 The Authors Journal compilation Institute of Zoology, Chinese Academy of Sciences, Insect Science, 16, 73-79

    E-print Network

    Trumble, John T.

    of exceptionally high levels of Mn and Ni. Key words detritivore, elemental defense, heavy metal, hyperaccumulator- rally and as anthropogenic contaminants. In serpentine soils, both metals may occur naturally are an increasing pollution problem (Alloway, 1990). Sources of Mn pollution include industrial metallurgy

  2. International Journal of Phytoremediation, 10:222235, 2008 Copyright C Taylor & Francis Group, LLC

    E-print Network

    Ma, Lena

    ISSN: 1522-6514 print / 1549-7879 online DOI: 10.1080/15226510801997754 PHYTOFILTRATION OF ARSENIC Natarajan,1 Robert H. Stamps,1 Uttam K. Saha,2 and Lena Q. Ma2 1 Institute of Food and Agricultural Science and nutrient levels on arsenic (As) removal by the As-hyperaccumulator Pteris vittata L. (Chinese brake fern

  3. Characteristics of arsenic accumulation by Pteris and non-Pteris ferns T. Luongo & L.Q. Ma1

    E-print Network

    Ma, Lena

    Characteristics of arsenic accumulation by Pteris and non-Pteris ferns T. Luongo & L.Q. Ma1 Soil author* Received 8 March 2005. Accepted in revised form 24 April 2005 Key words: arsenic, detoxification the mechanisms of arsenic hyperaccumulation in Pteris vittata by comparing the characteristics of arsenic

  4. Expression of a Pteris vittata glutaredoxin PvGRX5 in transgenic Arabidopsis thaliana increases plant arsenic

    E-print Network

    Ma, Lena

    plant arsenic tolerance and decreases arsenic accumulation in the leaves SABARINATH SUNDARAM1 , SHAN WU1, USA ABSTRACT Chinese brake fern Pteris vittata hyperaccumulates arsenic in its fronds. In a study to identify brake fern cDNAs in arsenic resistance, we implicated a glutaredoxin, PvGRX5, because when

  5. Author's personal copy Sulfate and glutathione enhanced arsenic accumulation by arsenic

    E-print Network

    Ma, Lena

    Author's personal copy Sulfate and glutathione enhanced arsenic accumulation by arsenic, Gainesville, FL 32611-0690, USA Sulfate and glutathione increased arsenic uptake and translocation in Pteris December 2009 Accepted 12 December 2009 Keywords: Sulfur Arsenic Hyperaccumulator GSH a b s t r a c

  6. NiO (bunsenite) is not available to Alyssum species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some species of the genus Alyssum are capable of accumulating up to 30 g kg-1 DW Ni in their leaves when grown on serpentine soils where these species are endemic. The unique ability of Alyssum species to hyperaccumulate high concentration of Ni stimulated basic research toward a better understandi...

  7. What about the rare-earth elements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is insufficient understanding of the nutritional physiology of pecan trees and orchards; thus, affecting nutmeat yield and quality, disease resistance and alternate bearing. An analysis of the rare-earth element composition of pecan and related hickory cousins found that they hyperaccumulate ...

  8. ORIGINAL ARTICLE Inoculation of Astragalus racemosus and Astragalus convallarius

    E-print Network

    ORIGINAL ARTICLE Inoculation of Astragalus racemosus and Astragalus convallarius with selenium Astragalus rac- emosus and the non-accumulator Astragalus convallarius. The fungi, Alternaria astragali (A3) and Fusarium acu- minatum (F30), were previously isolated from Astragalus hyperaccumulator rhizosphere. A3

  9. ORIGINAL ARTICLE Inoculation of Astragalus racemosus and Astragalus convallarius

    E-print Network

    ORIGINAL ARTICLE Inoculation of Astragalus racemosus and Astragalus convallarius with selenium, translocation, and chem- ical speciation in the hyperaccumulator Astragalus rac- emosus and the non-accumulator Astragalus convallarius. The fungi, Alternaria astragali (A3) and Fusarium acu- minatum (F30), were

  10. American Journal of Botany 99(12): 000000. 2012. American Journal of Botany 99(12): 112, 2012; http://www.amjbot.org/ 2012 Botanical Society of America

    E-print Network

    fluctuations in the soil environment and rhizosphere (Chalk et al., 2010). The Astragalus genus makes a good of Astragalus species do not hyperaccumulate elements, but a select number of species native to western North). Investigating Astragalus species may indicate if there is a coevolutionary relationship between plant

  11. Running head: Selenium and ecological partnerships in Astragalus1 Author for correspondence: Elizabeth A. H. Pilon-Smits, Biology Department, Colorado State3

    E-print Network

    1 Running head: Selenium and ecological partnerships in Astragalus1 2 Author for correspondence distribution and speciation in hyperaccumulator Astragalus bisulcatus9 and associated ecological partners10 11 Astragalus bisulcatus was collected in its natural seleniferous habitat, and X-ray40 fluorescence mapping

  12. Arsenic and heavy metal accumulation by Athyrium yokoscense from contaminated soils

    Microsoft Academic Search

    Tran Khanh Van; Yumei Kang; Takahiro Fukui; Katsutoshi Sakurai; K?z? Iwasaki; Yoshio Aikawa; Nguyen Minh Phuong

    2006-01-01

    Athyrium yokoscense, a type of fern that grows vigorously in mining areas in Japan, is well known as a Cd hyperaccumulator as well as a Cu, Pb and Zn tolerant plant. However, no information is available on As accumulation of A. yokoscense, although it often grows on soils containing high levels of both heavy metals and As. In this study, young

  13. Localization of Competing Metals (Ni, Co, and Zn) in Alyssum using micro-XRF and Tomography. (3564)

    E-print Network

    Sparks, Donald L.

    . These rare plants can be used to extract metals from contaminated sites (i.e. phytoextraction) or to mine.L. Sparks - Univ. of Delaware Abstract: Unique metal-accumulating plants (i.e. hyperaccumulators) have contaminated with Ni would likely have co-contaminants present that compete with Ni and alter the extraction

  14. This Article Figures Only

    E-print Network

    Sparks, Donald L.

    agents which cause unacceptable contaminant leaching and are cost prohibitive; and on plant species which these plants to achieve hyperaccumulation. Cadmium phytoextraction is needed #12;for rice soils contaminated and Biodegradation Heavy Metals Other Environmental Contamination HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH

  15. , Edward Peltier, R. L. Chaney, and Donald Sparks. The ASA-CSSA-SSSA International Annual Meetings

    E-print Network

    Sparks, Donald L.

    is part of: Trace Elements in Soils and Plants: I Speciation of Cobalt in Ni/Co Hyperaccumulator Using-term fate of trace metals in contaminated soil systems is a significant issue in environmental chemistry. Unique plant species have evolved an ability to accumulate large quantities of trace metals

  16. www.newphytologist.org 641 Blackwell Publishing Ltd

    E-print Network

    Sparks, Donald L.

    areas of land have been contaminated. Hyperaccumulator plants concentrate trace metals Plant and Soil Sciences, University of Delaware, Newark, DE 19716, USA; 2 Geological and Environmental-tolerance, accumulation and localization were investigated for A. murale exposed to metal co-contaminants. · A. murale

  17. Root-induced Changes in Metal Speciation in the Rhizosphere and

    E-print Network

    Sparks, Donald L.

    , Newark, USA 2 University of Delaware, Plant and Soil Sciences Department, 831 S. College, 156 Townsend Hall, Newark, 19717, USA (dlsparks@udel.edu) Hyperaccumulator plants concentrate trace metals in aerial biomass, and thereby offer sustainable treatment of metal-contaminated sites and an opportunity to mine

  18. PHYTOEXTRACTION OF HEAVY METALS

    E-print Network

    Blouin-Demers, Gabriel

    of phytoextraction as a means for removing heavy metals from contaminated soils The use of plants to remove contaminants from soils Contaminants must be in harvestable portions of the plant (Wongkongkatep et al. 2003 Plants Chelating agents Pb hyperaccumulation Effects of pH on metal extraction Disposal options

  19. Phytoremediation of metals, metalloids, and radionuclides

    Microsoft Academic Search

    S. P. McGrath; J. Zhao; E. Lombi

    2002-01-01

    Phytoremediation is a developing technology that can potentially address the problems of contaminated agricultural land or more intensely polluted areas affected by urban or industrial activities. Three main strategies currently exist to phytoextract inorganic substances from soils using plants:(1) use of natural hyperaccumulators; (2) enhancement of element uptake of high biomass species by chemical additions to soil and plants; and

  20. The Engineered Phytoremediation of Ionic and Methylmercury Pollution

    SciTech Connect

    Richard Meagher; Sarah Marshburn; Andrew Heaton; Anne Marie Zimer; Raoufa Rahman

    2003-06-24

    Our current specific objectives are to use transgenic plants to control the chemical species, electrochemical state, and above ground binding of mercury to (a) prevent methylmercury from entering the food-chain, (b) remove mercury from polluted sites, and (c) hyperaccumulate mercury in above ground tissues for later harvest.

  1. The Science of the Total Environment 300 (2002) 167177 0048-9697/02/$ -see front matter 2002 Elsevier Science B.V. All rights reserved.

    E-print Network

    Ma, Lena

    sources for drinking water. Phytoremediation, an emerging, plant-based technology for the removal of toxic open a door for phytoremediation of arsenic-contaminated soils. Speciation and distribution of arsenic B.V. All rights reserved. Keywords: Arsenic; Phytoremediation; Pteris vittata; Hyperaccumulator

  2. Characteristics of heavy metal uptake by plant species with potential for phytoremediation and phytomining

    Microsoft Academic Search

    T. V. Nedelkoska; P. M. Doran

    2000-01-01

    Genetically transformed hairy root cultures were established for a range of plant species and applied in studies of growth and accumulation of heavy metals. Experiments were conducted using liquid nutrient medium containing elevated concentrations of Ni, Cd or Cu. Hairy roots of three hyperaccumulator species were tested for Ni uptake, of these, Alyssum bertolonii accumulated the highest Ni contents in

  3. Analysis of Arsenic Uptake by Plant Species Selected for Growth in Northwest Ohio by ICP-OES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoremediation of arsenic-contaminated soils and water is a low maintenance, environmentally friendly alternative to more traditional remediation techniques. Hyperaccumulation of arsenic by plants (e.g. Pteris spp. and Pityrogramma calomelanos) is considered the most useful approach in phytoremed...

  4. Assessing Plants for Phytoremediation of Arsenic-Contaminated Soils

    E-print Network

    Ma, Lena

    24 Assessing Plants for Phytoremediation of Arsenic-Contaminated Soils Nandita Singh and Lena Q. Ma. Phytoremediation is potentially a cost-effective and environmentally benign method of extracting pollutants from soils. Key Words: Arsenic (As); hyperaccumulation; phytoremediation; Pteris vittata. 1. Introduction

  5. Abbreviations: As(V) Arsenate; As(III) Arsenite; MS Murashige and Skoog; PC Phytochelatin; SOD Superoxide dismutase Fig. 1 Inorganic forms of arsenic most prevalent in the

    E-print Network

    Ma, Lena

    and prefers calcareous soils. 32 Arsenic Hyperaccumulating Ferns and their Application to Phytoremediation-friendly and cost-effective phytoremediation technology for remediation of arsenic contaminated sites the phytoremediation potential of this fern. This review summarizes recent research on the mechanisms of arsenic

  6. Chinese Science Bulletin Vol. 50 No. 1 January 2005 33 Chinese Science Bulletin 2005 Vol. 50 No. 1 33 38

    E-print Network

    Ma, Lena

    and evolution. It provides a pat- entable new plant species for phytoremediation of Cd-con- taminated soils.1360/982004-292 Phytoremediation emerged in early the 1980s is an important technology for remedying contaminated sites. One of the most promising phytoremediation technologies is phytoextraction using hyperaccumulators to remove heavy

  7. An International Journal of Plant ISSN 0032-0935

    E-print Network

    on hyperaccumulators has been focused on their possible use for phytoremediation of contami- nated sites. Phytoremediation technology has promise as a cheap and environmentally friendly method to remove heavy metals et al. 2009). How- ever, phytoremediation has its challenges. Strong accumu- lators of toxic elements

  8. Gonzaga et al.90 Sci. Agric. (Piracicaba, Braz.), v.63, n.1, p.90-101, Jan./Feb. 2006

    E-print Network

    Ma, Lena

    to workers. Phytoextraction, a strategy of phytoremediation, uses plants to clean up contaminated soils of molecular biology seems to hold the key for the future of the phytoremediation. Key words: environmental contamination, hyperaccumulator plants, phytoremediation FITOEXTRAÃ?Ã?O E HIPERACUMULAÃ?Ã?O DE ARSÃ?NIO POR ESPÃ?CIES

  9. TOLERANCE OF HEAVY METALS IN VASCULAR PLANTS: ARSENIC HYPERACCUMULATIONBY

    E-print Network

    Ma, Lena

    a great promise to phytoremediation, a plant- driven environmentallybenign clean up process wherein qualifies as an arsenic hyperaccumulator and thus has potential application in phytoremediation of arsenic contaminated sites. In order to model a successful phytoremediation strategy fqr arsenic contaminated sites

  10. Metal-accumulating plants: The biological resource and its commercial exploitation is soil clean-up technology

    SciTech Connect

    Baker, A.J.M. [Univ. of Sheffield (United Kingdom); Reeves, R.D. [Massey Univ., Palmerston North (New Zealand)

    1996-12-31

    This presentation provides a broad overview of metal hyperaccumulator plants and biological accumulation technology. Plants that have been identified as having the greatest potentials for development as phytoremediator crops for metal-contaminated soils are very briefly discussed. Phytoextraction, rhizofiltration, and phytostabilization are briefly defined. Issues pertinent to large scale phytoremediation of soils are discussed, including biological and technological constraints.

  11. The effect of EDTA and citric acid on phytoremediation of Cd, Cr, and Ni from soil using Helianthus annuus

    Microsoft Academic Search

    Cafer Turgut; M. Katie Pepe; Teresa J. Cutright

    2004-01-01

    The possibility to clean heavy metal contaminated soils with hyperaccumulator plants has shown great potential. One of the most recently studied species used in phytoremediation applications are sunflowers. In this study, two cultivars of Helianthus annuus were used in conjunction with ethylene diamine tetracetic acid (EDTA) and citric acid (CA) as chelators. Two different concentrations of the chelators were studied

  12. SYNCHROTRON X-RAY ABSORPTION-EDGE COMPUTED MICROTOMOGRAPHY IMAGING OF THALLIUM COMPARTMENTALIZATION IN IBERIS INTERMEDIA

    EPA Science Inventory

    Thallium (TI) is an extremely toxic metal which, due to its similarities to K, is readily taken up by plants. Thallium is efficiently hyperaccumulated in Iberis intermedia as TI(I). Distribution and compartmentalization of TI in I. intermedia is highes...

  13. Molecular approach for phytoremediation of metal-contaminated sites

    Microsoft Academic Search

    Shilpa Goel; Jahid A. Malik; Harsh Nayyar

    2009-01-01

    Phytoremediation is the process which utilizes plants to extract, sequester, or detoxify pollutants in soils and surface waters. There are examples of many plants which can hyperaccumulate metals in their shoots. For example, Alyssum lesbiacum can be grown in Ni (II)-rich soil; nickel is rapidly transported into the plant and accumulates to 3% of the dry weight of above-ground tissues.

  14. Xylem exudate composition and root-to-shoot nickel translocation in Alyssum species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An improved understanding of Ni root-to-shoot translocation mechanism in hyperaccumulators is necessary to increase Ni uptake efficiency for phytoextraction technologies. It is presumed that an important aspect of Ni translocation and storage involves chelation with organic ligands. It has been re...

  15. Accumulation of zinc and cadmium and localization of zinc in Picris divaricata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Picris divaricata Vant., native to subtropical China, was recently identified as the first Cd/Zn hyper-accumulator from Asteraceae. Wild collected seed of P. divaricata was grown in a series of pH buffered test soils with Zn levels 00-7000 gkg-1 and Cd levels 00-150 gkg-1 for four months. Plants d...

  16. A Comparison of Sulfate and Selenium Accumulation in Relation to the Expression of Sulfate Transporter Genes in Astragalus Species1[OA

    PubMed Central

    Cabannes, Emmanuelle; Buchner, Peter; Broadley, Martin R.; Hawkesford, Malcolm J.

    2011-01-01

    Sulfate and selenate uptake were investigated in both selenium (Se) hyperaccumulators (Astragalus racemosus and Astragalus bisulcatus) and closely related nonaccumulator species (Astragalus glycyphyllos and Astragalus drummondii). Sulfur (S) starvation increased Se accumulation, whereas increased selenate supply increased sulfate accumulation in both root and shoot tissues. cDNAs for homologs of groups 1 to 4 sulfate transporters were cloned from these Astragalus species to investigate patterns of expression and interactions with sulfate and selenate uptake. In contrast to all other previously analyzed plant species, abundant gene expression of putative sulfate transporters was observed for both Se-hyperaccumulating and nonaccumulating Astragalus, regardless of S and Se status. Furthermore, quantitative analysis of expression indicated a transcript level in Se-hyperaccumulating Astragalus comparable with other plant species under S deprivation. The high expression of sulfate transporters in certain Astragalus species may lead to enhanced Se uptake and translocation ability and therefore may contribute to the Se hyperaccumulation trait; however, it is not sufficient to explain S/Se discriminatory mechanisms. PMID:21972267

  17. Selenium accumulation in flowers and its effects on pollination

    E-print Network

    juncea, floral visitor, hyperaccumulator, pollen germination, selenium (Se), Stanleya pinnata. Summary and plant­pollinator interactions. · Floral Se distribution and speciation were compared in Stanleya pinnata plants with high and low Se. · Stanleya pinnata preferentially allocated Se to flowers, as nontoxic

  18. DOI 10.1007/s00442-007-0907-8 PLANT-ANIMAL INTERACTIONS -ORIGINAL PAPER

    E-print Network

    of the Se hyperaccumulator Stanleya pinnata (prince's plume) that were pretreated with or without Se phytoremediation, or as Se-forti- Wed crops. Keywords Astragalus bisulcatus · Black-tailed prairie dog · Stanleya pinnata Introduction While many plant species growing on soils with high con- centrations of metals

  19. Selenium accumulation protects plants from herbivory by Orthoptera via toxicity and deterrence.

    PubMed

    Freeman, John L; Lindblom, Stormy Dawn; Quinn, Colin F; Fakra, Sirine; Marcus, Matthew A; Pilon-Smits, Elizabeth A H

    2007-01-01

    To investigate whether selenium (Se) accumulation in plants provides a chemical defense against generalist insect herbivores, the feeding preference and performance of a mix of orthopteran species were investigated. The selenium hyperaccumulator Stanleya pinnata and accumulator Brassica juncea were used in herbivory studies in the laboratory, and S. pinnata was also used in a manipulative field experiment. In laboratory studies, both crickets and grasshoppers avoided plants pretreated with selenate, while those given no choice died after eating leaves with elevated Se (447 +/- 68 and 230 +/- 68 microg Se g(-1) DW, respectively). B. juncea has previously been shown to accumulate selenate, while S. pinnata hyperaccumulates methyl-selenocysteine. Thus, these findings demonstrate that both inorganic and organic forms of selenium protect plants from herbivory. Grasshoppers fed S. pinnata contained methylselenocysteine in their midgut and absorbed this form into surrounding tissues. In a manipulative field experiment, methylselenocysteine protected S. pinnata from invertebrate herbivory and increased its long-term survival rate over an entire growth season. * In native habitats of selenium hyperaccumulators, orthopterans represent a major group of insect herbivores. Protection offered by organic selenium accumulation against these herbivores may have promoted the evolution of selenium hyperaccumulation in plants. PMID:17635224

  20. Journal of Experimental Botany, Page 1 of 8 doi:10.1093/jxb/err247

    E-print Network

    .1% of dry weight (DW), and Se hyperaccumulators such as Stanleya pinnata (Brassicaeae) contain between 0) RESEARCH PAPER Effects of selenium accumulation on reproductive functions in Brassica juncea and Stanleya pinnata Christine N. Prins, Laura J. Hantzis, Colin F. Quinn and Elizabeth A. H. Pilon-Smits* Department

  1. Imaging of selenium in plants using tapered metal monocapillary optics

    Microsoft Academic Search

    Ingrid J. Pickering; Gregory Hirsch; Roger C. Prince; Eileen Yu Sneeden; David E. Saltd; Graham N. Georgea

    2003-01-01

    Tapered metal monocapillary optics provide a potential alternative to conventional methods of producing small X-ray beams. This paper presents the initial results of chemically specific imaging using such devices. Cellular resolution of organic selenium is obtained in a longitudinal section of mature Astragalus bisulcatus, a selenium hyperaccumulating plant. This work demonstrates the utility of metal monocapillary optics for imaging dilute

  2. Forms of Zn Accumulkated in Arabidopsis halleri 1 Sarret G., Saumitou-Laprade P., Bert V., Proux O., Hazemann J. L., Traverse A., Marcus M. A. and

    E-print Network

    Paris-Sud XI, Université de

    and in the non-tolerant and non-accumulator Arabidopsis lyrata ssp. petraea were determined at the molecularForms of Zn Accumulkated in Arabidopsis halleri 1 Sarret G., Saumitou-Laprade P., Bert V., Proux O in the hyperaccumulator Arabidopsis halleri. Plant Physiol., 130, 1815-1826. Forms of Zn Accumulated

  3. Identification of a novel pathway involving a GATA transcription factor in yeast and possibly plant Zn uptake and homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain a better understanding of the regulation of Zn homeostasis in plants and the degree of conservation of Zn homeostasis between plants and yeast, a cDNA library from the Zn/Cd hyperaccumulating plant species, Nocceae caerulescens, was screened for its ability to restore growth under Zn limitin...

  4. Bioassisted Phytomining of Gold

    NASA Astrophysics Data System (ADS)

    Maluckov, Biljana S.

    2015-02-01

    Bioassisted phytomining implies targeted use of microorganisms and plants for the selective recovery of the metal. Metals from undissolved compounds are dissolved by applying specially chosen microorganisms and therefore become available to the hyperaccumulating plants. In the article, the selective extraction method of base metals and the precious metal gold by using microorganisms and plants is discussed.

  5. Evaluation of three ornamental plants for phytoremediation of Pb-contamined soil.

    PubMed

    Cui, Shuang; Zhang, Tingan; Zhao, Shanlin; Li, Ping; Zhou, Qixing; Zhang, Qianru; Han, Qing

    2013-01-01

    Characteristics of accumulation and tolerance of lead (Pb) in Quamolit pennata, Antirrhinum majus L. and Celosia cristata pyramidalis were investigated to identify Pb-accumulating plants. In this study, pot culture experiment was conducted to assess whether these plants are Pb-hyperaccumulators or accumulators. The results indicated that the Pb enrichment factor (concentration in plant/soil) and Pb translocation factor (concentration in shoot/root) of these plants were principally <1 in pot culture and concentration gradient experiments. However, the Pb concentration in Celosia cristata pyramidalis shoots was higher than 1000 mg kg(-1), the threshold concentration for a Pb-hyperaccumulator. Shoot biomass of Celosia cristata pyramidalis had no significantly (p < 0.05) variation compared to the control. Based on these results, only Celosia cristata pyramidalis could be identified as a Pb-accumulator. PMID:23487996

  6. Enhancement of Phosphate Absorption by Garden Plants by Genetic Engineering: A New Tool for Phytoremediation

    PubMed Central

    Togami, Junichi; Mason, John G.; Chandler, Stephen F.; Tanaka, Yoshikazu

    2013-01-01

    Although phosphorus is an essential factor for proper plant growth in natural environments, an excess of phosphate in water sources causes serious pollution. In this paper we describe transgenic plants which hyperaccumulate inorganic phosphate (Pi) and which may be used to reduce environmental water pollution by phytoremediation. AtPHR1, a transcription factor for a key regulator of the Pi starvation response in Arabidopsis thaliana, was overexpressed in the ornamental garden plants Torenia, Petunia, and Verbena. The transgenic plants showed hyperaccumulation of Pi in leaves and accelerated Pi absorption rates from hydroponic solutions. Large-scale hydroponic experiments indicated that the enhanced ability to absorb Pi in transgenic torenia (AtPHR1) was comparable to water hyacinth a plant that though is used for phytoremediation causes overgrowth problems. PMID:23984322

  7. Phytoremediation of ionic and methylmercury pollution

    SciTech Connect

    Meagher, Richard B

    2010-04-28

    Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and . water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and to aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.

  8. Phytoremediative urban design: transforming a derelict and polluted harbour area into a green and productive neighbourhood.

    PubMed

    Wilschut, M; Theuws, P A W; Duchhart, I

    2013-12-01

    Many urban areas are polluted by industrial activities and waste disposal in landfills. Since conventional soil remediation techniques are costly and unsustainable, phytoremediation might offer an alternative. In this article, we explore how phytoremediation can be integrated into the transformation of urban post-industrial areas, while improving public space. Buiksloterham, a polluted and deprived industrial area in Amsterdam, serves as case study. Buiksloterham is polluted with heavy metals, with Zinc (Zn) concentrations being the highest. A regression-model for Alpine Pennycress (Thlaspi caerulescens) is used to estimate the time needed to remediate the site. This reveals a conflict in time between remediation and urban development. A research by design experiment shows how to overcome this conflict by dealing with polluted soil innovatively while emphasizing spatial and aesthetic qualities of the phytoremediation plant species. The resulting landscape framework integrates phytoremediation with biomass production and gives new ecological, economic and social value to Buiksloterham. PMID:23452757

  9. Decomposition of Zn-rich Arabidopsis halleri Litter in Low and High Metal Soil in the Presence and Absence of EDTA

    Microsoft Academic Search

    Krishan Chander; Rainer Georg Joergensen

    2008-01-01

    Hyperaccumulating plants are increasingly investigated in combination with EDTA addition to soil for phytoremediation of heavy\\u000a metal contaminated soils. A 60-day incubation experiment was carried out to investigate the effects of heavy metal release\\u000a during the decomposition of Zn-rich (15.7 mg g?1 dry weight) Arabidopsis halleri litter on C mineralization, microbial biomass C, biomass N, ATP, and adenylate energy charge (AEC).

  10. Plant diversity reduces the effect of multiple heavy metal pollution on soil enzyme activities and microbial community structure

    Microsoft Academic Search

    Yang Gao; Chiyuan Miao; Jun Xia; Liang Mao; Yafeng Wang; Pei Zhou

    It is unclear whether certain plant species and plant diversity could reduce the impacts of multiple heavy metal pollution\\u000a on soil microbial structure and soil enzyme activities. Random amplified polymorphic DNA (RAPD) was used to analyze the genetic\\u000a diversity and microbial similarity in planted and unplanted soil under combined cadmium (Cd) and lead (Pb) pollution. A metal\\u000a hyperaccumulator, Brassica juncea,

  11. Molecular cloning and characterization of a phytochelatin synthase gene, PvPCS1, from Pteris vittata L.

    PubMed

    Dong, Ruibin; Formentin, Elide; Losseso, Carmen; Carimi, Francesco; Benedetti, Piero; Terzi, Mario; Schiavo, Fiorella Lo

    2005-12-01

    Pteris vittata L. is a staggeringly efficient arsenic hyperaccumulator that has been shown to be capable of accumulating up to 23,000 microg arsenic g(-1), and thus represents a species that may fully exploit the adaptive potential of plants to toxic metals. However, the molecular mechanisms of adaptation to toxic metal tolerance and hyperaccumulation remain unknown, and P. vittata genes related to metal detoxification have not yet been identified. Here, we report the isolation of a full-length cDNA sequence encoding a phytochelatin synthase (PCS) from P. vittata. The cDNA, designated PvPCS1, predicts a protein of 512 amino acids with a molecular weight of 56.9 kDa. Homology analysis of the PvPCS1 nucleotide sequence revealed that it has low identity with most known plant PCS genes except AyPCS1, and the homology is largely confined to two highly conserved regions near the 5'-end, where the similarity is as high as 85-95%. The amino acid sequence of PvPCS1 contains two Cys-Cys motifs and 12 single Cys, only 4 of which (Cys-56, Cys-90/91, and Cys-109) in the N-terminal half of the protein are conserved in other known PCS polypeptides. When expressed in Saccharomyces cerevisae, PvPCS1 mediated increased Cd tolerance. Cloning of the PCS gene from an arsenic hyperaccumulator may provide information that will help further our understanding of the genetic basis underlying toxic metal tolerance and hyperaccumulation. PMID:15918023

  12. Phytoremediation of arsenic contaminated paddy soils with Pteris vittata markedly reduces arsenic uptake by rice

    Microsoft Academic Search

    Wen-Ling Ye; M. Asaduzzaman Khan; Steve P. McGrath; Fang-Jie Zhao

    2011-01-01

    Arsenic (As) accumulation in food crops such as rice is of major concern. To investigate whether phytoremediation can reduce As uptake by rice, the As hyperaccumulator Pteris vittata was grown in five contaminated paddy soils in a pot experiment. Over a 9-month period P. vittata removed 3.5–11.4% of the total soil As, and decreased phosphate-extractable As and soil pore water As

  13. Analysis of Sulfur And Selenium Assimilation in 'Astragalus' Plants With Varying Capacities to Accumulate Selenium

    SciTech Connect

    Sors, T.G.; Ellis, D.R.; Na, G.Nam.; Lahner, B.; Lee, S.; Leustek, T.; Pickering, I.J.; Salt, D.E.; /Purdue U. /Rutgers U., Piscataway /Saskatchewan U.

    2007-08-08

    Several Astragalus species have the ability to hyperaccumulate selenium (Se) when growing in their native habitat. Given that the biochemical properties of Se parallel those of sulfur (S), we examined the activity of key S assimilatory enzymes ATP sulfurylase (ATPS), APS reductase (APR), and serine acetyltransferase (SAT), as well as selenocysteine methyltransferase (SMT), in eight Astragalus species with varying abilities to accumulate Se. Se hyperaccumulation was found to positively correlate with shoot accumulation of S-methylcysteine (MeCys) and Se-methylselenocysteine (MeSeCys), in addition to the level of SMT enzymatic activity. However, no correlation was observed between Se hyperaccumulation and ATPS, APR, and SAT activities in shoot tissue. Transgenic Arabidopsis thaliana overexpressing both ATPS and APR had a significant enhancement of selenate reduction as a proportion of total Se, whereas SAT overexpression resulted in only a slight increase in selenate reduction to organic forms. In general, total Se accumulation in shoots was lower in the transgenic plants overexpressing ATPS, PaAPR, and SAT. Root growth was adversely affected by selenate treatment in both ATPS and SAT overexpressors and less so in the PaAPR transgenic plants. Such observations support our conclusions that ATPS and APR are major contributors of selenate reduction in planta. However, Se hyperaccumulation in Astragalus is not driven by an overall increase in the capacity of these enzymes, but rather by either an increased Se flux through the S assimilatory pathway, generated by the biosynthesis of the sink metabolites MeCys or MeSeCys, or through an as yet unidentified Se assimilation pathway.

  14. Soil Amendments Affecting Nickel and Cobalt Uptake by Berkheya coddii: Potential Use for Phytomining and Phytoremediation

    Microsoft Academic Search

    B. H. ROBINSON; R. R. BROOKS; B. E. CLOTHIER

    1999-01-01

    Plants with inordinately high concentrations of heavy metals (‘hyperaccumulators’) can be used for phytoremediation (removal of contaminants from soils) or phytomining (growing a crop of plants to harvest the metals). Pot trials were used to investigate the effects of MgCO3, CaCO3, sulphur, chelating agents (NTA, DTPA, EDTA) and acid mine tailings on nickel and cobalt uptake by the South African

  15. Phytoremediation of soil metals

    Microsoft Academic Search

    Rufus L Chaney; Minnie Malik; Yin M Li; Sally L Brown; Eric P Brewer; J Scott Angle; Alan JM Baker

    1997-01-01

    The phytoremediation of metal-contaminated soils offers a low-cost method for soil remediation and some extracted metals may be recycled for value. Both the phytoextraction of metals and the phytovolatilization of Se or Hg by plants offer great promise for commercial development. Natural metal hyperaccumulator phenotype is much more important than high-yield ability when using plants to remove metals from contaminated

  16. Use of synchrotron radiation to characterize metals in plants: the case of Cd in the hyperacumulator Arabidopsis halleri

    NASA Astrophysics Data System (ADS)

    Isaure, M.; Sarret, G.; Verbruggen, N.

    2010-12-01

    Phytoremediation uses plants to extract (phytoextraction) or stabilize (phytostabilization) metals accumulated in soils, and can be an alternative to invasive physico-chemical remediation techniques. Its development requires the knowledge of the mechanisms involved in metal tolerance and accumulation in plants, and particularly the way that plants transfer and store metals. In that context, synchrotron radiation based techniques such as micro-focused X-Ray Fluorescence (µXRF), and micro-focused X-ray Absorption Spectroscopy, including Extended X-ray Absorption Fine Structure and X-ray Absorption Near Edge Structure, are particularly suited to determine the localization and the chemical forms of metals in the different tissues, cells and sub-cellular compartments. Arabidopsis halleri is a Zn, Cd hyperaccumulating plant, naturally growing on contaminated sites, and is a model plant to investigate metal hyperaccumulation. This work presents the application of µXRF and Cd µXANES to determine the distribution and speciation of Cd in this species. Results showed that Cd was mainly located in the mesophyll and veins of leaves. It is bound to S ligands in some leaves and to O/N ligands in other ones, and the observed variations may be related to the age of the leaves. Cd speciation seems to differ from other metals, and particularly Zn, generally encountered in hyperaccumulators. High local Cd concentrations were also detected at the base of trichomes, epidermal hairs of leaves, associated to O/N ligands, probably to the cell wall. This phenomenon was also observed on non-hyperaccumulators and is clearly not the major sink for Cd, but trichomes might play a role in the detoxification process. This study illustrates the suitability of synchrotron radiation based techniques to investigate metal distribution and speciation in plants.

  17. Short-rotation woody crops and phytoremediation: Opportunities for agroforestry?

    Microsoft Academic Search

    D. L. Rockwood; C. V. Naidu; D. R. Carter; M. Rahmani; T. A. Spriggs; C. Lin; G. R. Alker; J. G. Isebrands; S. A. Segrest

    2004-01-01

    Worldwide, fuelwood demands, soil and groundwater contamination, and agriculture's impact on nature are growing concerns.\\u000a Fast growing trees in short rotation woody crop (SRWC) systems may increasingly meet societal needs ranging from renewable\\u000a energy to environmental mitigation and remediation. Phytoremediation, the use of plants for environmental cleanup, systems\\u000a utilizing SRWCs have potential to remediate contaminated soil and groundwater. Non-hyperaccumulating, i.e.,

  18. Selenium phytoremediation potential of Stanleya pinnata

    Microsoft Academic Search

    David R. Parker; Laura J. Feist; Tracey W. Varvel; David N. Thomason; Yiqiang Zhang

    2003-01-01

    Disposal of saline irrigation wastewater in hydrologically closed sinks in the semi-arid western U.S. has concentrated selenium-rich salts to hazardous levels and phytoextraction, along with plant-enhanced volatilization of methyl-selenides, is an active area of research. Here, we provide an overview of our ongoing studies of Stanleya pinnata (Brassicaceae), a previously unstudied candidate that is a primary accumulator (hyperaccumulator) of Se

  19. Chemical-assisted phytoremediation of Cd-PAHs contaminated soils using Solanum nigrum L

    Microsoft Academic Search

    Chuanjie Yang; Qixing Zhou; Shuhe Wei; Yahu Hu; Yanyu Bao

    2011-01-01

    A well-characterized cadmium (Cd) hyperaccumulating plant Solanum nigrum was grown in Cd and polycyclic aromatic hydrocarbons (PAHs) co-contaminated soil that was repeatedly amended with chemicals, including EDTA, cysteine (CY), salicylic acid (Sa) and Tween 80 (TW80), to test individual and combined treatment effects on phytoremediation of Cd-PAHs contaminated soils. Plant growth was negatively affected by exogenous chemicals except for EDTA.

  20. The potential of Sedum alfredii Hance for the biosorption of some metals from synthetic wastewater

    Microsoft Academic Search

    Ji Bing Xiong; Qaisar Mahmood; Min Yue

    2011-01-01

    The capacity of a terrestrial Zn\\/Cd hyperaccumulator Sedum alfredii Hance to purify water polluted by Zn, Cd, Cu and Pb along with their removal pathway was investigated. S. alfredii Hance was grown in synthetic wastewater in 2.5-L capacity containers contaminated with (mgL?1) 19.20 Zn, 11.24 Cd, 3.27 Cu and 0.53 Pb, respectively. The supplied metal concentrations were comparable with those

  1. Lead tolerance and accumulation in the gametophytes of the fern Athyrium yokoscense

    Microsoft Academic Search

    Hiroyuki Kamachi; Ippei Komori; Hideo Tamura; Yoshimi Sawa; Ichirou Karahara; Yoshihiro Honma; Naoya Wada; Tokimasa Kawabata; Kenji Matsuda; Susumu Ikeno; Munenori Noguchi; Hiroshi Inoue

    2005-01-01

    The fern Athyrium yokoscense is known to be highly tolerant to lead toxicity, and is a lead hyperaccumulator that can accumulate over 1,000 µg g-1 of lead in its dry matter. In this work, we examined whether the gametophytic generation of A. yokoscense also resists lead toxicity like the sporophytic generation. Spore germination in A. yokoscense was more tolerant to Pb2+, compared

  2. Molecular Aspects of Regulation of Collagen Gene Expression in Fibrosis

    Microsoft Academic Search

    Rashpal K. Bhogal; Cristina M. Stoica; Tracy L. McGaha; Constantin A. Bona

    2005-01-01

    Fibrosis, the hyper-accumulation of scar tissue, is characterized by the overproduction and deposition of type I and III collagen\\u000a by fibroblasts and is the one of the main pathologic outcomes of the autoimmune disorder scleroderma. While the causes of\\u000a fibrosis in scleroderma are unknown, cytokines such as TGF-?, IL-4 and IL-13, play a crucial role in the stimulation of collagen

  3. Selenium tolerance in Astragalus chrysochlorus : identification of a cDNA fragment encoding a putative Selenocysteine methyltransferase

    Microsoft Academic Search

    ?ule Ar?; Özgür Çak?r; Neslihan Turgut-Kara

    2010-01-01

    Selenium (Se) plays an indispensable role in human nutrition and has been implicated to have important health benefits, including\\u000a being a cancer preventative agent. Selected members of the genus Astragalus (Fabaceae) are known for their ability to accumulate high levels of selenium, mainly in the form of methyl-selenocysteine\\u000a (MeSeCys). The Se-hyperaccumulator Astragalus bisulcatus metabolizes >90% of the accumulated Se into

  4. Imaging of selenium in plants using tapered metal monocapillary optics.

    PubMed

    Pickering, Ingrid J; Hirsch, Gregory; Prince, Roger C; Sneeden, Eileen Yu; Salt, David E; George, Graham N

    2003-05-01

    Tapered metal monocapillary optics provide a potential alternative to conventional methods of producing small X-ray beams. This paper presents the initial results of chemically specific imaging using such devices. Cellular resolution of organic selenium is obtained in a longitudinal section of mature Astragalus bisulcatus, a selenium hyperaccumulating plant. This work demonstrates the utility of metal monocapillary optics for imaging dilute levels of target elements in biological tissues. PMID:12714765

  5. Selenite precipitation by a rhizospheric strain of Stenotrophomonas sp. isolated from the root system of Astragalus bisulcatus: a biotechnological perspective

    Microsoft Academic Search

    Simona Di Gregorio; Silvia Lampis; Giovanni Vallini

    2005-01-01

    A bacterial strain (SeITE02), related to the species Stenotrophomonas maltophilia and resistant to selenite (SeIV) up to 50 mM in the growth medium, was isolated from rhizospheric soil of a selenium hyperaccumulator plant, the legume Astragalus bisulcatus. The influence of SeIV on the active growth of this Se-tolerant bacterial strain has been investigated in oxic conditions, along with the isolate's

  6. Overexpressing both ATP sulfurylase and selenocysteine methyltransferase enhances selenium phytoremediation traits in Indian mustard

    Microsoft Academic Search

    Danika L. LeDuc; Manal AbdelSamie; Maria Móntes-Bayon; Carol P. Wu; Sarah J. Reisinger; Norman Terry

    2006-01-01

    A major goal of our selenium (Se) phytoremediation research is to use genetic engineering to develop fast-growing plants with an increased ability to tolerate, accumulate, and volatilize Se. To this end we incorporated a gene (encoding selenocysteine methyltransferase, SMT) from the Se hyperaccumulator, Astragalus bisulcatus, into Indian mustard (LeDuc, D.L., Tarun, A.S., Montes-Bayón, M., Meija, J., Malit, M.F., Wu, C.P.,

  7. Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium

    Microsoft Academic Search

    Adam J. Matich; Marian J. McKenzie; David A. Brummell; Daryl D. Rowan

    2009-01-01

    Nicotiana tabacum L. (tobacco) plants were transformed to overexpress a selenocysteine methyltransferase gene from the selenium hyperaccumulator Astragalus bisulcatus (Hook.) A. Gray (two-grooved milkvetch), and an ATP-sulfurylase gene from Brassica oleracea L. var. italica (broccoli). Solvent extraction of leaves harvested from plants treated with selenate revealed five selenium-containing compounds, of which four were identified by chemical synthesis as 2-(methylseleno)acetaldehyde, 2,2-bis(methylseleno)acetaldehyde,

  8. Shining light on metals in the environment

    SciTech Connect

    McNear, Jr., D.H.; Tappero, R.; Sparks, D.L. (Delaware)

    2010-07-20

    Elucidating the speciation of heavy metals in the environment is paramount to understanding their potential mobility and bioavailability. Cutting-edge synchrotron-based techniques such as microfocused X-ray absorption fine-structure (XAFS) and X-ray fluorescence (XRF) spectroscopy and microtomography have revolutionized the way metal reactions and processes in natural systems are studied. In this article, we apply these intense-light tools to decipher metal forms (species) and associations in contaminated soils and metal-hyperaccumulating plants.

  9. Lithium, Vanadium and Chromium Uptake Ability of Brassica juncea from Lithium Mine Tailings.

    PubMed

    Elektorowicz, M; Keropian, Z

    2015-01-01

    The potential for phytoremediation and phytostabilization of lithium in lieu with vanadium and chromium on a formulated acidic heterogeneous growth media engineered around lithium mine tailings, was investigated in four phases: (1) overall efficiency of the removal of the three metals, (2) bioaccumulation ratios of the three metals, (3) overall relative growth rate, and (4) translocation index of the three metals in the physiology of the hyperaccumulator plant. A pot study was conducted to assess the suitability of Brassica juncea (Indian mustard) in a phytoremediation process whereby it was lingered for eighty-six days under homogeneous growth conditions and irrigated bidaily with organic fertilizer amended with LiCl. A post harvest data analysis was achieved through ashing and the implementation of cold digestion procedure in a concentrated hydrochloric acidic matrix. In physiological efficiency parameters, the hyperaccumulator plant was twice as able to phytostabilize chromium and four times was able to phytostabilize vanadium in comparison to lithium. Moreover, it was extremely efficient in translocating and accumulating lithium inside its upper physiological sites, more so than chromium and vanadium, thereby demonstrating Indian mustard, as a hyperaccumulator plant, for phytoextraction and phytostabilization in an acidic heterogeneous rhizosphere, with an extremely low relative growth rate. PMID:25747238

  10. Bioavailability assessment and accumulation by five garden flower species grown in artificially cadmium-contaminated soils.

    PubMed

    Lin, Chun-Chun; Lai, Hung-Yu; Chen, Zueng-Sang

    2010-07-01

    Many studies have been conducted on phytoextraction; however, non-native hyperaccumulator species are not suitable for the natural environment of Taiwan in many cases. Drawing upon previous results, the growth and heavy metal accumulation in artificially cadmium-contaminated soils were compared for five local garden flower species. The treatments included a control (CK), 9.73 +/- 0.05 mg kg(-1) (Cd-10), and 17.6 +/- 0.8 mg kg(-1) (Cd-20). All plants were harvested at 35 days after transplanting and analyzed for Cd content. Cd accumulation in the shoot of French marigold (Tagetes patula L.) and Impatiens (Impatiens walleriana Hook. f.) grown in Cd-20 treatment were 66.3 +/- 6.5 and 100 +/- 11 mg kg(-1), which equated to a removal of 0.80 +/- 0.11 and 0.60 +/- 0.37 mg Cd plant(-1), respectively. The maximum Cd accumulation of Impatiens reached the threshold value (100 mg kg(-1)) characteristic of a Cd hyperaccumulator and its bioconcentration factor (BCF) and translocation factor (TF) were greater than one. Impatiens therefore has the potential to hyperaccumulate Cd from Cd-contaminated soils. With the exception of Garden verbena, significant relationships were found between Cd concentrations in soil extracted by 0.05 M EDTA, 0.005 M DTPA, and 0.01 M CaCl2 and the concentration of Cd in the shoots of the tested garden flowers. PMID:21166288

  11. Deletion of the Gene Encoding the Cyclin-Dependent Protein Kinase Pho85 Alters Glycogen Metabolism in Saccharomyces Cerevisiae

    PubMed Central

    Timblin, B. K.; Tatchell, K.; Bergman, L. W.

    1996-01-01

    Pho85, a protein kinase with significant homology to the cyclin-dependent kinase, Cdc28, has been shown to function in repression of transcription of acid phosphatase (APase, encoded by PHO5) in high phosphate (Pi) medium, as well as in regulation of the cell cycle at G1/S. We describe several unique phenotypes associated with the deletion of the PHO85 gene including growth defects on a variety of carbon sources and hyperaccumulation of glycogen in rich medium high in Pi. Hyperaccumulation of glycogen in the pho85 strains is independent of other APase regulatory molecules and is not signaled through Snf1 kinase. However, constitutive activation of cAPK suppresses the hyperaccumulation of glycogen in a pho85 mutant. Mutation of the type-1 protein phosphatase encoded by GLC7 only partially suppresses the glycogen phenotype of the pho85 mutant. Additionally, strains containing a deletion of the PHO85 gene show an increase in expression of GSY2. This work provides evidence that Pho85 has functions in addition to transcriptional regulation of APase and cell-cycle progression including the regulation of glycogen levels in the cell and may provide a link between the nutritional state of the cell and these growth related responses. PMID:8722762

  12. Exploring lower limits of plant elemental defense by cobalt, copper, nickel, and zinc.

    PubMed

    Cheruiyot, Dorothy J; Boyd, Robert S; Moar, William J

    2013-05-01

    Elemental defense is a relatively newly recognized phenomenon in which plants use elements present in their tissue to reduce damage by herbivores or pathogens. In the present study, neonates of the generalist herbivore, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), were fed artificial diets amended with varying concentrations of Co, Cu, Ni, and Zn that are hyperaccumulated by plants to determine minimum lethal concentrations (MLC) and minimum sublethal concentrations (MSC) for each metal. MLC values (dry mass) for Co (45 ?g/g), Ni (230 ?g/g), and Zn (280 ?g/g) were below published minimum hyperaccumulator levels. MSC levels (dry mass) for Co (15 ?g/g), Ni (140 ?g/g), and Zn (200 ?g/g) were at concentrations lower than published minimum accumulator levels. Furthermore, both MLC and MSC values for Zn were within normal tissue concentrations. These results indicate that elemental defense for Co, Ni, and Zn may be effective at concentrations lower than hyperaccumulator levels and so may be more widespread than previously believed. PMID:23584612

  13. Cd and Zn accumulation in plants from the Padaeng zinc mine area.

    PubMed

    Phaenark, C; Pokethitiyook, P; Kruatrachue, M; Ngernsansaruay, C

    2009-07-01

    Significant cadmium (Cd) contamination In soil and rice has been discovered in Mae Sot, Tak province, Thailand where the rice-based agricultural systems are established in the vicinity of a zinc mine. The prolonged consumption of Cd contaminated rice has potential risks to public health and health impacts of Cd exposed populations in Mae Sot have been demonstrated. The Thai government has prohibited rice cultivation in the area as an effort to prevent further exposure. Phytoextraction, the use of plants to remove contaminants from soil, is a potential option to manage Cd-contaminated areas. However, successful phytoextraction depends on first identifying effective hyperaccumulator plants appropriate for local climatic conditions. Five sampling sites at Padaeng Zinc mine, Tak province were selected to collect plant and soil samples. Total Cd and Zn concentrations in sediments or soils were approximately 596 and 20,673 mg kg(-1) in tailing pond area, 543 and 20,272 mg kg(-1) in open pit area, 894 and 31,319 mg kg(-1) in stockpile area, 1458 and 57,012 mg kg(-1) in forest area and 64 and 2733 mg kg(-1) in Cd contaminated rice field. Among a total of 36 plant species from 16 families, four species (Chromolaena odoratum, Gynura pseudochina, Impatiens violaeflora and Justicia procumbens) could be considered as Cd hyperaccumulators since their shoot Cd concentrations exceeded 100 mg Cd kg(-1) dry mass and they showed a translocation factor >1. Only Justicia procumbens could be considered as a Zn hyperaccumulator (Zn concentration in its shoot more than 10,000 mg Zn kg(-1) dry mass with the translocation factor >1). PMID:19810350

  14. Ecophysiology of nickel phytoaccumulation: a simplified biophysical approach.

    PubMed

    Coinchelin, David; Bartoli, François; Robin, Christophe; Echevarria, Guillaume

    2012-10-01

    Solute active transport or exclusion by plants can be identified by the values of the Transpiration Stream Concentration Factor (TSCF=xylem:solution solute concentration ratio). The aim of this study was to estimate this parameter for Ni uptake by the Ni-hyperaccumulator Leptoplax emarginata or the Ni-excluder Triticum aestivum cultivar 'Fidel'. The Intact Plant TSCF for nickel (IPTSCF(Ni)) was calculated as the ratio between the nickel mass accumulation in the leaves and the nickel concentration in solution per volume of water transpired. Predominantly, Ni active transport occurred for L. emarginata, with IPTSCF(Ni) values of 4.7-7.2 and convective component proportions of the root Ni uptake flow of only 15-20% for a range of Ni concentrations in solutions of 2-16 µmol Ni l(-1), regardless of the growth period and the time of Ni uptake. Hyperaccumulator roots were permeable to both water and nickel (mean reflection coefficient for Ni, ?(Ni), of 0.06), which was mainly attributed to an absence of exodermis. Results provide a new view of the mechanisms of Ni hyperaccumulation. By contrast, the wheat excluder was characterized by an extremely low mean IPTSCF(Ni) value of 0.006, characterizing a predominantly Ni sequestration in roots. From a methodological viewpoint, the 'microscopic' TSCF(Ni), measured directly on excised plants was 2.4 times larger than its recommended 'macroscopic' IPTSCF(Ni) counterpart. Overall, IPTSCF and ? determined on intact transpiring plants appeared to be very useful biophysical parameters in the study of the mechanisms involved in metal uptake and accumulation by plants, and in their modelling. PMID:22987839

  15. Screening of plant species for phytoremediation of uranium, thorium, barium, nickel, strontium and lead contaminated soils from a uranium mill tailings repository in South China.

    PubMed

    Li, Guang-yue; Hu, Nan; Ding, De-xin; Zheng, Ji-fang; Liu, Yu-long; Wang, Yong-dong; Nie, Xiao-qin

    2011-06-01

    The concentrations of uranium, thorium, barium, nickel, strontium and lead in the samples of the tailings and plant species collected from a uranium mill tailings repository in South China were analyzed. Then, the removal capability of a plant for a target element was assessed. It was found that Phragmites australis had the greatest removal capabilities for uranium (820 ?g), thorium (103 ?g) and lead (1,870 ?g). Miscanthus floridulus had the greatest removal capabilities for barium (3,730 ?g) and nickel (667 ?g), and Parthenocissus quinquefolia had the greatest removal capability for strontium (3,920 ?g). In this study, a novel coefficient, termed as phytoremediation factor (PF), was proposed, for the first time, to assess the potential of a plant to be used in phytoremediation of a target element contaminated soil. Phragmites australis has the highest PFs for uranium (16.6), thorium (8.68), barium (10.0) and lead (10.5). Miscanthus floridulus has the highest PF for Ni (25.0). Broussonetia papyrifera and Parthenocissus quinquefolia have the relatively high PFs for strontium (28.1 and 25.4, respectively). On the basis of the definition for a hyperaccumulator, only Cyperus iria and Parthenocissus quinquefolia satisfied the criteria for hyperaccumulator of uranium (36.4 ?g/g) and strontium (190 ?g/g), and could be the candidates for phytoremediation of uranium and strontium contaminated soils. The results show that the PF has advantage over the hyperaccumulator in reflecting the removal capabilities of a plant for a target element, and is more adequate for assessing the potential of a plant to be used in phytoremediation than conventional method. PMID:21523506

  16. Agromining: farming for metals in the future?

    PubMed

    van der Ent, Antony; Baker, Alan J M; Reeves, Roger D; Chaney, Rufus L; Anderson, Christopher W N; Meech, John A; Erskine, Peter D; Simonnot, Marie-Odile; Vaughan, James; Morel, Jean Louis; Echevarria, Guillaume; Fogliani, Bruno; Rongliang, Qiu; Mulligan, David R

    2015-04-21

    Phytomining technology employs hyperaccumulator plants to take up metal in harvestable plant biomass. Harvesting, drying and incineration of the biomass generates a high-grade bio-ore. We propose that "agromining" (a variant of phytomining) could provide local communities with an alternative type of agriculture on degraded lands; farming not for food crops, but for metals such as nickel (Ni). However, two decades after its inception and numerous successful experiments, commercial phytomining has not yet become a reality. To build the case for the minerals industry, a large-scale demonstration is needed to identify operational risks and provide "real-life" evidence for profitability. PMID:25700109

  17. The green clean: The emerging field of phytoremediation takes root

    SciTech Connect

    Brown, K.S.

    1995-10-01

    A few plants can biologically accumulate toxic metals from surrounding soils, a situation that could revolutionize environmental cleanup. By breeding a planting metal-munchers like alpine pennycress, scientist plan to clease waste zones of toxic levels of zinc, nickel and lead. From soil loaded with metal to radionuclide-laden water, researcher hope phytoremediation will provide a cheap way to clean man-made messes at mining, nuclear, and industrial sites. This article describes developments in the area of phytoremediation, including sections on plants called hyperaccumulators, how phytoremediators function, problems transferring phytoremediators from hydroculture to soils and problems which might prevent use of phytoremediators.

  18. Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium.

    PubMed

    Matich, Adam J; McKenzie, Marian J; Brummell, David A; Rowan, Daryl D

    2009-06-01

    Nicotiana tabacum L. (tobacco) plants were transformed to overexpress a selenocysteine methyltransferase gene from the selenium hyperaccumulator Astragalus bisulcatus (Hook.) A. Gray (two-grooved milkvetch), and an ATP-sulfurylase gene from Brassica oleracea L. var. italica (broccoli). Solvent extraction of leaves harvested from plants treated with selenate revealed five selenium-containing compounds, of which four were identified by chemical synthesis as 2-(methylseleno)acetaldehyde, 2,2-bis(methylseleno)acetaldehyde, 4-(methylseleno)-(2E)-nonenal, and 4-(methylseleno)-(2E,6Z)-nonadienal. These four compounds have not previously been reported in nature. PMID:19570557

  19. A transcriptomic network underlies microstructural and physiological responses to cadmium in Populus x canescens.

    PubMed

    He, Jiali; Li, Hong; Luo, Jie; Ma, Chaofeng; Li, Shaojun; Qu, Long; Gai, Ying; Jiang, Xiangning; Janz, Dennis; Polle, Andrea; Tyree, Melvin; Luo, Zhi-Bin

    2013-05-01

    Bark tissue of Populus × canescens can hyperaccumulate cadmium, but microstructural, transcriptomic, and physiological response mechanisms are poorly understood. Histochemical assays, transmission electron microscopic observations, energy-dispersive x-ray microanalysis, and transcriptomic and physiological analyses have been performed to enhance our understanding of cadmium accumulation and detoxification in P. × canescens. Cadmium was allocated to the phloem of the bark, and subcellular cadmium compartmentalization occurred mainly in vacuoles of phloem cells. Transcripts involved in microstructural alteration, changes in nutrition and primary metabolism, and stimulation of stress responses showed significantly differential expression in the bark of P. × canescens exposed to cadmium. About 48% of the differentially regulated transcripts formed a coregulation network in which 43 hub genes played a central role both in cross talk among distinct biological processes and in coordinating the transcriptomic regulation in the bark of P. × canescens in response to cadmium. The cadmium transcriptome in the bark of P. × canescens was mirrored by physiological readouts. Cadmium accumulation led to decreased total nitrogen, phosphorus, and calcium and increased sulfur in the bark. Cadmium inhibited photosynthesis, resulting in decreased carbohydrate levels. Cadmium induced oxidative stress and antioxidants, including free proline, soluble phenolics, ascorbate, and thiol compounds. These results suggest that orchestrated microstructural, transcriptomic, and physiological regulation may sustain cadmium hyperaccumulation in P. × canescens bark and provide new insights into engineering woody plants for phytoremediation. PMID:23530184

  20. Evaluation of micro-energy dispersive X-ray fluorescence and histochemical tests for aluminium detection in plants from High Altitude Rocky Complexes, Southeast Brazil.

    PubMed

    Campos, Naiara V; Pereira, Tiago A R; Machado, Mariana F; Guerra, Marcelo B B; Tolentino, Gláucia S; Araújo, Josiane S; Rezende, Maíra Q; Silva, Maria Carolina N A da; Schaefer, Carlos E G R

    2014-03-01

    The soils developed under High Altitude Rocky Complexes in Brazil are generally of very low chemical fertility, with low base saturation and high exchangeable aluminium concentration. This stressful condition imposes evolutionary pressures that lead to ecological success of plant species that are able to tolerate or accumulate high amounts of aluminium. Several analytical methods are currently available for elemental mapping of biological structures, such as micro-X-ray fluorescence (?-EDX) and histochemical tests. The aim of this study was to combine ?-EDX analysis and histochemical tests to quantify aluminium in plants from High Altitude Rocky Complexes, identifying the main sites for Al-accumulation. Among the studied species, five showed total Al concentration higher than 1000 mg kg-1. The main Al-hyperaccumulator plants, Lavoisiera pectinata, Lycopodium clavatum and Trembleya parviflora presented positive reactions in the histochemical tests using Chrome Azurol and Aluminon. Strong positive correlations were observed between the total Al concentrations and data obtained by ?-EDX analysis. The ?-EDX analysis is a potential tool to map and quantify Al in hyperaccumulator species, and a valuable technique due to its non-destructive capacity. Histochemical tests can be helpful to indicate the accumulation pattern of samples before they are submitted for further ?-EDX scrutiny. PMID:24676168

  1. Selenium accumulation in flowers and its effects on pollination.

    PubMed

    Quinn, Colin F; Prins, Christine N; Freeman, John L; Gross, Amanda M; Hantzis, Laura J; Reynolds, Ray J B; Yang, Soo in; Covey, Paul A; Bañuelos, Gary S; Pickering, Ingrid J; Fakra, Sirine C; Marcus, Matthew A; Arathi, H S; Pilon-Smits, Elizabeth A H

    2011-11-01

    • Selenium (Se) hyperaccumulation has a profound effect on plant-arthropod interactions. Here, we investigated floral Se distribution and speciation in flowers and the effects of floral Se on pollen quality and plant-pollinator interactions. • Floral Se distribution and speciation were compared in Stanleya pinnata, an Se hyperaccumulator, and Brassica juncea, a comparable nonhyperaccumulator. Pollen germination was measured from plants grown with varying concentrations of Se and floral visitation was compared between plants with high and low Se. • Stanleya pinnata preferentially allocated Se to flowers, as nontoxic methyl-selenocysteine (MeSeCys). Brassica juncea had higher Se concentrations in leaves than flowers, and a lower fraction of MeSeCys. For B. juncea, high floral Se concentration impaired pollen germination; in S. pinnata Se had no effect on pollen germination. Floral visitors collected from Se-rich S. pinnata contained up to 270 ?g g(-1), concentrations toxic to many herbivores. Indeed, floral visitors showed no visitation preference between high- and low-Se plants. Honey from seleniferous areas contained 0.4-1 ?g Se g(-1), concentrations that could provide human health benefits. • This study is the first to shed light on the possible evolutionary cost, through decreased pollen germination in B. juncea, of Se accumulation and has implications for the management of seleniferous areas. PMID:21793829

  2. [Effects of Bacillus mucilaginosus on the Cd content of rhizosphere soil and enzymes in soil of Brassica juncea].

    PubMed

    Yang, Rong; Li, Bo-Wen; Liu, Wei

    2013-06-01

    The effects of two inoculation concentrations of Bacillus mucilaginosus (1 x 10(10) (treatment A), 2 x 10(10) (treatment C) CFU x kg(-1)) on the Cd content of rhizosphere soil and enzymes in soil were investigated when Brassica as a hyperaccumulator grew in the pots experiment. The results showed that the removal rate of rhizosphere soil Cd in treatment A and C were 37.62% and 38.27%, respectively, which were 1.54 and 1.56 times as high as that of the control (24.47%). The activities of urease, phosphatase and catalase in rhizosphere were higher than those in non-rhizosphere. The urease, catalase and dehydrogenase activities increased firstly and then decreased, while the phosphatase activity increased gradually with time. However, the dehydrogenase activity in non-rhizophere was higher than that in rhizosphere. Correlation analysis showed negative correlation between content of Cd and urease and phosphatase in the control treatment and significantly negative correlation between content of Cd and activities urease and phosphatase in treatment A and C in rhizosphere. The results indicated that inoculation of Bacillus mucilaginosus not only had some positive effect on urease, phosphatase, catalase and dehydrogenase in soil but also improved the purification effect of hyperaccumulator on soil Cd. This study provides theoretical guidance for the further mechanism study of Microbe-Phytoremediation. PMID:23947067

  3. Plants absorb heavy metals

    SciTech Connect

    Parry, J.

    1995-02-01

    Decontamination of heavy metals-polluted soils remains one of the most intractable problems of cleanup technology. Currently available techniques include extraction of the metals by physical and chemical means, such as acid leaching and electroosmosis, or immobilization by vitrification. There are presently no techniques for cleanup which are low cost and retain soil fertility after metals removal. But a solution to the problem could be on the horizon. A small but growing number of plants native to metalliferous soils are known to be capable of accumulating extremely high concentrations of metals in their aboveground portions. These hyperaccumulators, as they are called, contain up to 1,000 times larger metal concentrations in their aboveground parts than normal species. Their distribution is global, including many different families of flowering plants of varying growth forms, from herbaceous plants to trees. Hyperaccumulators absorb metals they do not need for their own nutrition. The metals are accumulated in the leaf and stem vacuoles, and to a lesser extent in the roots.

  4. Roles of plant metal tolerance proteins (MTP) in metal storage and potential use in biofortification strategies.

    PubMed

    Ricachenevsky, Felipe K; Menguer, Paloma K; Sperotto, Raul A; Williams, Lorraine E; Fett, Janette P

    2013-01-01

    Zinc (Zn) is an essential micronutrient for plants, playing catalytic or structural roles in enzymes, transcription factors, ribosomes, and membranes. In humans, Zn deficiency is the second most common mineral nutritional disorder, affecting around 30% of the world's population. People living in poverty usually have diets based on milled cereals, which contain low Zn concentrations. Biofortification of crops is an attractive cost-effective solution for low mineral dietary intake. In order to increase the amounts of bioavailable Zn in crop edible portions, it is necessary to understand how plants take up, distribute, and store Zn within their tissues, as well as to characterize potential candidate genes for biotechnological manipulation. The metal tolerance proteins (MTP) were described as metal efflux transporters from the cytoplasm, transporting mainly Zn(2+) but also Mn(2+), Fe(2+), Cd(2+), Co(2+), and Ni(2+). Substrate specificity appears to be conserved in phylogenetically related proteins. MTPs characterized so far in plants have a role in general Zn homeostasis and tolerance to Zn excess; in tolerance to excess Mn and also in the response to iron (Fe) deficiency. More recently, the first MTPs in crop species have been functionally characterized. In Zn hyperaccumulator plants, the MTP1 protein is related to hypertolerance to elevated Zn concentrations. Here, we review the current knowledge on this protein family, as well as biochemical functions and physiological roles of MTP transporters in Zn hyperaccumulators and non-accumulators. The potential applications of MTP transporters in biofortification efforts are discussed. PMID:23717323

  5. The Psychedelic Genes of Maize Redundantly Promote Carbohydrate Export From Leaves

    PubMed Central

    Slewinski, Thomas L.; Braun, David M.

    2010-01-01

    Whole-plant carbohydrate partitioning involves the assimilation of carbon in leaves and its translocation to nonphotosynthetic tissues. This process is fundamental to plant growth and development, but its regulation is poorly understood. To identify genes controlling carbohydrate partitioning, we isolated mutants that are defective in exporting fixed carbon from leaves. Here we describe psychedelic (psc), a new mutant of maize (Zea mays) that is perturbed in carbohydrate partitioning. psc mutants exhibit stable, discrete chlorotic and green regions within their leaves. psc chlorotic tissues hyperaccumulate starch and soluble sugars, while psc green tissues appear comparable to wild-type leaves. The psc chlorotic and green tissue boundaries are usually delineated by larger veins, suggesting that translocation of a mobile compound through the veins may influence the tissue phenotype. psc mutants display altered biomass partitioning, which is consistent with reduced carbohydrate export from leaves to developing tissues. We determined that the psc mutation is unlinked to previously characterized maize leaf carbohydrate hyperaccumulation mutants. Additionally, we found that the psc mutant phenotype is inherited as a recessive, duplicate-factor trait in some inbred lines. Genetic analyses with other maize mutants with variegated leaves and impaired carbohydrate partitioning suggest that Psc defines an independent pathway. Therefore, investigations into the psc mutation have uncovered two previously unknown genes that redundantly function to regulate carbohydrate partitioning in maize. PMID:20142436

  6. Inhibition of the ubiquitin-proteasome pathway alters cellular levels of nitric oxide in tomato seedlings.

    PubMed

    Negi, Sangeeta; Santisree, Parankusam; Kharshiing, Eros Vasil; Sharma, Rameshwar

    2010-09-01

    Nitric oxide (NO) is involved in diverse plant growth processes; however, little is known about pathways regulating NO levels in plants. In this study, we isolated a NO-overproducing mutant of tomato (Solanum lycopersicum) in which hyper-accumulation of NO, associated with increase in nitric oxide synthase (NOS)-like activity, caused diminished vegetative growth of plants and showed delayed flowering. The hyper-accumulation of NO caused drastic shortening of primary root (shr) in the seedlings, while the scavenging of NO restored root elongation in shr mutant. Inhibition of NOS-like activity reduced NO levels and stimulated root elongation in the shr mutant seedlings, while inhibition of nitrate reductase (NR) activity could not rescue shr phenotype. The stimulation of NO levels in shr mutant also conferred increased resistance to pathogen Pseudomonas syringae. Application of pharmacological inhibitors regulating ubiquitin-proteasome pathway reduced NO levels and NOS-like activity and stimulated shr root elongation. Our data indicate that a signaling pathway involving regulated protein degradation likely regulates NO synthesis in tomato. PMID:20603380

  7. Phenotypic and molecular consequences of overexpression of metal-homeostasis genes

    PubMed Central

    Antosiewicz, Danuta M.; Barabasz, Anna; Siemianowski, Oskar

    2014-01-01

    Metal hyperaccumulating plants are able to store very large amounts of metals in their shoots. There are a number of reasons why it is important to be able to introduce metal hyperaccumulation traits into non-accumulating species (e.g., phytoremediation or biofortification in minerals) and to engineer a desired level of accumulation and distribution of metals. Metal homeostasis genes have therefore been used for these purposes. Engineered accumulation levels, however, have often been far from expected, and transgenic plants frequently display phenotypic features not related to the physiological function of the introduced gene. In this review, we focus on an aspect often neglected in research on plants expressing metal homeostasis genes: the specific regulation of endogenous metal homeostasis genes of the host plant in response to the transgene-induced imbalance of the metal status. These modifications constitute one of the major mechanisms involved in the generation of the plant's phenotype, including unexpected characteristics. Interestingly, activation of so-called “metal cross-homeostasis” has emerged as a factor of primary importance. PMID:24639682

  8. A Transcriptomic Network Underlies Microstructural and Physiological Responses to Cadmium in Populus × canescens1[C][W

    PubMed Central

    He, Jiali; Li, Hong; Luo, Jie; Ma, Chaofeng; Li, Shaojun; Qu, Long; Gai, Ying; Jiang, Xiangning; Janz, Dennis; Polle, Andrea; Tyree, Melvin; Luo, Zhi-Bin

    2013-01-01

    Bark tissue of Populus × canescens can hyperaccumulate cadmium, but microstructural, transcriptomic, and physiological response mechanisms are poorly understood. Histochemical assays, transmission electron microscopic observations, energy-dispersive x-ray microanalysis, and transcriptomic and physiological analyses have been performed to enhance our understanding of cadmium accumulation and detoxification in P. × canescens. Cadmium was allocated to the phloem of the bark, and subcellular cadmium compartmentalization occurred mainly in vacuoles of phloem cells. Transcripts involved in microstructural alteration, changes in nutrition and primary metabolism, and stimulation of stress responses showed significantly differential expression in the bark of P. × canescens exposed to cadmium. About 48% of the differentially regulated transcripts formed a coregulation network in which 43 hub genes played a central role both in cross talk among distinct biological processes and in coordinating the transcriptomic regulation in the bark of P. × canescens in response to cadmium. The cadmium transcriptome in the bark of P. × canescens was mirrored by physiological readouts. Cadmium accumulation led to decreased total nitrogen, phosphorus, and calcium and increased sulfur in the bark. Cadmium inhibited photosynthesis, resulting in decreased carbohydrate levels. Cadmium induced oxidative stress and antioxidants, including free proline, soluble phenolics, ascorbate, and thiol compounds. These results suggest that orchestrated microstructural, transcriptomic, and physiological regulation may sustain cadmium hyperaccumulation in P. × canescens bark and provide new insights into engineering woody plants for phytoremediation. PMID:23530184

  9. Expression of a Pteris vittata glutaredoxin PvGRX5 in transgenic Arabidopsis thaliana increases plant arsenic tolerance and decreases arsenic accumulation in the leaves.

    PubMed

    Sundaram, Sabarinath; Wu, Shan; Ma, Lena Q; Rathinasabapathi, Bala

    2009-07-01

    Chinese brake fern Pteris vittata hyperaccumulates arsenic in its fronds. In a study to identify brake fern cDNAs in arsenic resistance, we implicated a glutaredoxin, PvGRX5, because when expressed in Escherichia coli, it improved arsenic tolerance in recombinant bacteria. Here, we asked whether PvGRX5 transgenic expression would alter plant arsenic tolerance and metabolism. Two lines of Arabidopsis thaliana constitutively expressing PvGrx5 cDNA were compared with vector control and wild-type lines. PvGRX5-expressors were significantly more tolerant to arsenic compared with control lines based on germination, root growth and whole plant growth under imposed arsenic stress. PvGRX5-expressors contained significantly lower total arsenic compared with control lines following treatment with arsenate. Additionally, PvGRX5-expressors were significantly more efficient in their arsenate reduction in vivo. Together, our results indicate that PvGRX5 has a role in arsenic tolerance via improving arsenate reduction and regulating cellular arsenic levels. Paradoxically, our results suggest that PvGRX5 from the arsenic hyperaccumulator fern can be used in a novel biotechnological solution to decrease arsenic in crops. PMID:19236608

  10. Molecular Genetics of Metal Detoxification: Prospects for Phytoremediation

    SciTech Connect

    Ow, David W. ow@pgec.ams.usda.gov

    2000-09-01

    Unlike compounds that can be broken down, the remediation of most heavy metals and radionuclides requires physical extraction from contaminated sources. Plants can extract inorganics, but effective phytoextraction requires plants that produce high biomass, grow rapidly and possess high capacity-uptake for the inorganic substance. Either hyperaccumulator plants must be bred for increased growth and biomass or hyperaccumulation traits must be engineered into fast growing, high biomass plants. This latter approach requires fundamental knowledge of the molecular mechanisms in the uptake and storage of inorganics. Much has been learned in recent years on how plants and certain fungi chelate and transport selected heavy metals. This progress has been facilitated by the use of Schizosaccharomyces pombe as a model system. The use of a model organism for study permits rapid characterization of the molecular process. As target genes are identified in a model organism, their sequences can be modified for expression in a heterologous host or aid in the search of homologous genes in more complex organisms. Moreover, as plant nutrient uptake is intrinsically linked to the association with rhizospheric fungi, elucidating metal sequestration in this fungus permits additional opportunities for engineering rhizospheric microbes to assist in phytoextraction.

  11. Arsenic uptake and metabolism in plants.

    PubMed

    Zhao, F J; Ma, J F; Meharg, A A; McGrath, S P

    2009-03-01

    Arsenic (As) is an element that is nonessential for and toxic to plants. Arsenic contamination in the environment occurs in many regions, and, depending on environmental factors, its accumulation in food crops may pose a health risk to humans.Recent progress in understanding the mechanisms of As uptake and metabolism in plants is reviewed here. Arsenate is taken up by phosphate transporters. A number of the aquaporin nodulin26-like intrinsic proteins (NIPs) are able to transport arsenite,the predominant form of As in reducing environments. In rice (Oryza sativa), arsenite uptake shares the highly efficient silicon (Si) pathway of entry to root cells and efflux towards the xylem. In root cells arsenate is rapidly reduced to arsenite, which is effluxed to the external medium, complexed by thiol peptides or translocated to shoots. One type of arsenate reductase has been identified, but its in planta functions remain to be investigated. Some fern species in the Pteridaceae family are able to hyperaccumulate As in above-ground tissues. Hyperaccumulation appears to involve enhanced arsenate uptake, decreased arsenite-thiol complexation and arsenite efflux to the external medium, greatly enhanced xylem translocation of arsenite, and vacuolar sequestration of arsenite in fronds. Current knowledge gaps and future research directions are also identified. PMID:19207683

  12. Effects of selenium accumulation on reproductive functions in Brassica juncea and Stanleya pinnata

    PubMed Central

    Prins, Christine N.; Hantzis, Laura J.; Quinn, Colin F.; Pilon-Smits, Elizabeth A. H.

    2011-01-01

    Selenium (Se) is an essential micronutrient for many organisms, but is also a toxin and environmental pollutant at elevated levels. Due to its chemical similarity to sulphur, most plants readily take up and assimilate Se. Se accumulators such as Brassica juncea can accumulate Se between 0.01% and 0.1% of dry weight (DW), and Se hyperaccumulators such as Stanleya pinnata (Brassicaeae) contain between 0.1% and 1.5% DW of Se. While Se accumulation offers the plant a variety of ecological benefits, particularly protection from herbivory, its potential costs are still unexplored. This study examines the effects of plant Se levels on reproductive functions. In B. juncea, Se concentrations >0.05–0.1% caused decreases in biomass, pollen germination, individual seed and total seed weight, number of seeds produced, and seed germination. In S. pinnata there was no negative effect of increased Se concentration on pollen germination. In cross-pollination of B. juncea plants with different Se levels, both the maternal and paternal Se level affected reproduction, but the maternal Se concentration had the most pronounced effect. Interestingly, high-Se maternal plants were most efficiently pollinated by Se-treated paternal plants. These data provide novel insights into the potential reproductive costs of Se accumulation, interactive effects of Se in pollen grains and in the pistil, and the apparent evolution of physiological tolerance mechanisms in hyperaccumulators to avoid reproductive repercussions. PMID:21841173

  13. Mechanisms of lichen resistance to metallic pollution

    SciTech Connect

    Sarret, C.; Manceau, A.; Eybert-Berard, L. [Univ. of Grenoble and CNRS (France). Environmental Geochemistry Group] [Univ. of Grenoble and CNRS (France). Environmental Geochemistry Group; Cuny, D.; Haluwyn, C. van [Lab. de Botanique et de Cryptogamie, Lille (France)] [Lab. de Botanique et de Cryptogamie, Lille (France); Deruelle, S. [Institut d`Ecologie, Paris (France)] [Institut d`Ecologie, Paris (France); Hazemann, J.L.; Menthonnex, J.J. [Univ. of Grenoble and CNRS (France). Environmental Geochemistry Group] [Univ. of Grenoble and CNRS (France). Environmental Geochemistry Group; [CNRS, Grenoble (France). Lab. de Cristallographie; Soldo, Y. [CNRS, Grenoble (France). Lab. de Cristallographie] [CNRS, Grenoble (France). Lab. de Cristallographie

    1998-11-01

    Some lichens have a unique ability to grow in heavily contaminated areas due to the development of adaptative mechanisms allowing a high tolerance to metals. Here the authors report on the chemical forms of Pb and Zn in the metal hyperaccumulator Diploschistes muscorum and of Pb in the metal tolerant lichen Xanthoria parietina. The speciation of Zn and Pb has been investigated by powder X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy using the advanced third-generation synchrotron radiation source of the European synchrotron radiation facility (ESRF in Grenoble). This study reveals that in both lichens cells are protected from toxicity by complexation of heavy metals, but the strategies differ: in D. muscorum, Pb and Zn are accumulated through an enhanced synthesis of oxalate, which precipitates toxic elements as insoluble salts, whereas in X. parietina, Pb is complexed to carboxylic groups of the fungal cell walls. The authors conclude that hyperaccumulation of metals results from a reactive mechanism of organic acid production, whereas metallo-tolerance is achieved by a passive complexation to existing functional groups.

  14. Behavior of native species Arrhenatherum elatius (Poaceae) and Sonchus transcaspicus (Asteraceae) exposed to a heavy metal-polluted field: plant metal concentration, phytotoxicity, and detoxification responses.

    PubMed

    Lu, Yan; Li, Xinrong; He, Mingzhu; Zeng, Fanjiang

    2013-01-01

    The application of vegetation cover for the phytomanagement of heavy metal-polluted soils needs prior investigation on the suitability of plant species. In this study, behaviors of Arrhenatherum elatius and Sonchus transcaspicus, two native perennial grasses that currently grow in a mine tailing, were investigated through plant metal concentration, phytotoxicity and their detoxification responses. Both of the species accumulated Ni, Cu, Cd, Co, Mn, Pb, Cr, and Zn in shoots far below criterion concentration as a hyperaccumulators; thus, neither of them were found to be hyperaccumulators. A. elatius accumulated metals in roots and then in shoots, on the contrary, in S. transcaspicus metals were preferentially accumulated in shoots. Plants exposure to such metals resulted in oxidative stress in the considered organs as indicated by the changes in chlorophyll fluorescence, chlorophyll contents, malondialdehyde (MDA) levels and antioxidative enzyme activities. A. elatius seemed to be more affected by metal-induced oxidative stress than S. transcaspicus. Correspondingly, S. transcaspicus showed a greater capacity to adapt to metal-induced oxidative stress, depending on more effective antioxidative defense mechanisms to protect itself from oxidative damage. These findings allowed us to conclude that both of these plant species could be suitable for the phytostabilization of metal-polluted soils. PMID:23819286

  15. Effects of selenium accumulation on reproductive functions in Brassica juncea and Stanleya pinnata.

    PubMed

    Prins, Christine N; Hantzis, Laura J; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2011-11-01

    Selenium (Se) is an essential micronutrient for many organisms, but is also a toxin and environmental pollutant at elevated levels. Due to its chemical similarity to sulphur, most plants readily take up and assimilate Se. Se accumulators such as Brassica juncea can accumulate Se between 0.01% and 0.1% of dry weight (DW), and Se hyperaccumulators such as Stanleya pinnata (Brassicaeae) contain between 0.1% and 1.5% DW of Se. While Se accumulation offers the plant a variety of ecological benefits, particularly protection from herbivory, its potential costs are still unexplored. This study examines the effects of plant Se levels on reproductive functions. In B. juncea, Se concentrations >0.05-0.1% caused decreases in biomass, pollen germination, individual seed and total seed weight, number of seeds produced, and seed germination. In S. pinnata there was no negative effect of increased Se concentration on pollen germination. In cross-pollination of B. juncea plants with different Se levels, both the maternal and paternal Se level affected reproduction, but the maternal Se concentration had the most pronounced effect. Interestingly, high-Se maternal plants were most efficiently pollinated by Se-treated paternal plants. These data provide novel insights into the potential reproductive costs of Se accumulation, interactive effects of Se in pollen grains and in the pistil, and the apparent evolution of physiological tolerance mechanisms in hyperaccumulators to avoid reproductive repercussions. PMID:21841173

  16. Control of Zn uptake in Arabidopsis halleri: a balance between Zn and Fe

    PubMed Central

    Shanmugam, Varanavasiappan; Lo, Jing-Chi; Yeh, Kuo-Chen

    2013-01-01

    Zinc (Zn) is an essential plant micronutrient but is toxic in excess. To cope with excess Zn, plant species possess a strict metal homeostasis mechanism. The Zn hyperaccumulator Arabidopsis halleri has developed various adaptive mechanisms involving uptake, chelation, translocation and sequestration of Zn. In this mini review, we broadly discuss the different Zn tolerance mechanisms and then focus on controlled Zn uptake in A. halleri. Members of the ZRT/IRT-like protein (ZIP) family of metal transporters are mainly regulated by Zn and are involved in Zn uptake. A few members of the ZIP family, such as IRT1 and IRT2, are regulated by iron (Fe) and can transport multi-metals, including Zn, Fe, Mn, Cd, and Co. This mini-review also discusses the differential expression of multiple metal ZIP transporters in A. halleri and A. thaliana, a non-hyperaccumulator, with Zn exposure as well as Fe deficiency and their role in controlled Zn uptake and tolerance. PMID:23966999

  17. Roles of plant metal tolerance proteins (MTP) in metal storage and potential use in biofortification strategies

    PubMed Central

    Ricachenevsky, Felipe K.; Menguer, Paloma K.; Sperotto, Raul A.; Williams, Lorraine E.; Fett, Janette P.

    2013-01-01

    Zinc (Zn) is an essential micronutrient for plants, playing catalytic or structural roles in enzymes, transcription factors, ribosomes, and membranes. In humans, Zn deficiency is the second most common mineral nutritional disorder, affecting around 30% of the world's population. People living in poverty usually have diets based on milled cereals, which contain low Zn concentrations. Biofortification of crops is an attractive cost-effective solution for low mineral dietary intake. In order to increase the amounts of bioavailable Zn in crop edible portions, it is necessary to understand how plants take up, distribute, and store Zn within their tissues, as well as to characterize potential candidate genes for biotechnological manipulation. The metal tolerance proteins (MTP) were described as metal efflux transporters from the cytoplasm, transporting mainly Zn2+ but also Mn2+, Fe2+, Cd2+, Co2+, and Ni2+. Substrate specificity appears to be conserved in phylogenetically related proteins. MTPs characterized so far in plants have a role in general Zn homeostasis and tolerance to Zn excess; in tolerance to excess Mn and also in the response to iron (Fe) deficiency. More recently, the first MTPs in crop species have been functionally characterized. In Zn hyperaccumulator plants, the MTP1 protein is related to hypertolerance to elevated Zn concentrations. Here, we review the current knowledge on this protein family, as well as biochemical functions and physiological roles of MTP transporters in Zn hyperaccumulators and non-accumulators. The potential applications of MTP transporters in biofortification efforts are discussed. PMID:23717323

  18. Chemically Induced Conditional Rescue of the Reduced Epidermal Fluorescence8 Mutant of Arabidopsis Reveals Rapid Restoration of Growth and Selective Turnover of Secondary Metabolite Pools1[C][OPEN

    PubMed Central

    Kim, Jeong Im; Ciesielski, Peter N.; Donohoe, Bryon S.; Chapple, Clint; Li, Xu

    2014-01-01

    The phenylpropanoid pathway is responsible for the biosynthesis of diverse and important secondary metabolites including lignin and flavonoids. The reduced epidermal fluorescence8 (ref8) mutant of Arabidopsis (Arabidopsis thaliana), which is defective in a lignin biosynthetic enzyme p-coumaroyl shikimate 3?-hydroxylase (C3?H), exhibits severe dwarfism and sterility. To better understand the impact of perturbation of phenylpropanoid metabolism on plant growth, we generated a chemically inducible C3?H expression construct and transformed it into the ref8 mutant. Application of dexamethasone to these plants greatly alleviates the dwarfism and sterility and substantially reverses the biochemical phenotypes of ref8 plants, including the reduction of lignin content and hyperaccumulation of flavonoids and p-coumarate esters. Induction of C3?H expression at different developmental stages has distinct impacts on plant growth. Although early induction effectively restored the elongation of primary inflorescence stem, application to 7-week-old plants enabled them to produce new rosette inflorescence stems. Examination of hypocotyls of these plants revealed normal vasculature in the newly formed secondary xylem, presumably restoring water transport in the mutant. The ref8 mutant accumulates higher levels of salicylic acid than the wild type, but depletion of this compound in ref8 did not relieve the mutant’s growth defects, suggesting that the hyperaccumulation of salicylic acid is unlikely to be responsible for dwarfism in this mutant. PMID:24381065

  19. A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana.

    PubMed

    Orsini, Francesco; D'Urzo, Matilde Paino; Inan, Gunsu; Serra, Sara; Oh, Dong-Ha; Mickelbart, Michael V; Consiglio, Federica; Li, Xia; Jeong, Jae Cheol; Yun, Dae-Jin; Bohnert, Hans J; Bressan, Ray A; Maggio, Albino

    2010-08-01

    Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt tolerance research is largely neglected. The recent introduction of halophytic Arabidopsis-Relative Model Species (ARMS) has begun to compare and relate several unique genetic resources to the well-developed Arabidopsis model. In a search for candidates to begin to understand, through genetic analyses, the biological bases of salt tolerance, 11 wild relatives of Arabidopsis thaliana were compared: Barbarea verna, Capsella bursa-pastoris, Hirschfeldia incana, Lepidium densiflorum, Malcolmia triloba, Lepidium virginicum, Descurainia pinnata, Sisymbrium officinale, Thellungiella parvula, Thellungiella salsuginea (previously T. halophila), and Thlaspi arvense. Among these species, highly salt-tolerant (L. densiflorum and L. virginicum) and moderately salt-tolerant (M. triloba and H. incana) species were identified. Only T. parvula revealed a true halophytic habitus, comparable to the better studied Thellungiella salsuginea. Major differences in growth, water transport properties, and ion accumulation are observed and discussed to describe the distinctive traits and physiological responses that can now be studied genetically in salt stress research. PMID:20595237

  20. A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana

    PubMed Central

    Orsini, Francesco; D'Urzo, Matilde Paino; Inan, Gunsu; Serra, Sara; Oh, Dong-Ha; Mickelbart, Michael V.; Consiglio, Federica; Jeong, Jae Cheol; Yun, Dae-Jin; Bohnert, Hans J.; Bressan, Ray A.; Maggio, Albino

    2010-01-01

    Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt tolerance research is largely neglected. The recent introduction of halophytic Arabidopsis-Relative Model Species (ARMS) has begun to compare and relate several unique genetic resources to the well-developed Arabidopsis model. In a search for candidates to begin to understand, through genetic analyses, the biological bases of salt tolerance, 11 wild relatives of Arabidopsis thaliana were compared: Barbarea verna, Capsella bursa-pastoris, Hirschfeldia incana, Lepidium densiflorum, Malcolmia triloba, Lepidium virginicum, Descurainia pinnata, Sisymbrium officinale, Thellungiella parvula, Thellungiella salsuginea (previously T. halophila), and Thlaspi arvense. Among these species, highly salt-tolerant (L. densiflorum and L. virginicum) and moderately salt-tolerant (M. triloba and H. incana) species were identified. Only T. parvula revealed a true halophytic habitus, comparable to the better studied Thellungiella salsuginea. Major differences in growth, water transport properties, and ion accumulation are observed and discussed to describe the distinctive traits and physiological responses that can now be studied genetically in salt stress research. PMID:20595237