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1

Cadmium hyperaccumulation and genetic differentiation of Thlaspi caerulescens populations  

E-print Network

Cadmium hyperaccumulation and genetic differentiation of Thlaspi caerulescens populations Nevena hyperaccumulation mechanisms is increasing, the genetic basis of cadmium (Cd) hyperaccumulation remains fragment length polymorphism (AFLP); Cadmium (Cd); Genetic differentiation; Hyperaccumulation; Outlier loci

Alvarez, Nadir

2

Constitutively elevated salicylic acid signals glutathione-mediated nickel tolerance in Thlaspi nickel hyperaccumulators.  

PubMed

Progress is being made in understanding the biochemical and molecular basis of nickel (Ni)/zinc (Zn) hyperaccumulation in Thlaspi; however, the molecular signaling pathways that control these mechanisms are not understood. We observed that elevated concentrations of salicylic acid (SA), a molecule known to be involved in signaling induced pathogen defense responses in plants, is a strong predictor of Ni hyperaccumulation in the six diverse Thlaspi species investigated, including the hyperaccumulators Thlaspi goesingense, Thlaspi rosulare, Thlaspi oxyceras, and Thlaspi caerulescens and the nonaccumulators Thlaspi arvense and Thlaspi perfoliatum. Furthermore, the SA metabolites phenylalanine, cinnamic acid, salicyloyl-glucose, and catechol are also elevated in the hyperaccumulator T. goesingense when compared to the nonaccumulators Arabidopsis (Arabidopsis thaliana) and T. arvense. Elevation of free SA levels in Arabidopsis, both genetically and by exogenous feeding, enhances the specific activity of serine acetyltransferase, leading to elevated glutathione and increased Ni resistance. Such SA-mediated Ni resistance in Arabidopsis phenocopies the glutathione-based Ni tolerance previously observed in Thlaspi, suggesting a biochemical linkage between SA and Ni tolerance in this genus. Intriguingly, the hyperaccumulator T. goesingense also shows enhanced sensitivity to the pathogen powdery mildew (Erysiphe cruciferarum) and fails to induce SA biosynthesis after infection. Nickel hyperaccumulation reverses this pathogen hypersensitivity, suggesting that the interaction between pathogen resistance and Ni tolerance and hyperaccumulation may have played a critical role in the evolution of metal hyperaccumulation in the Thlaspi genus. PMID:15734913

Freeman, John L; Garcia, Daniel; Kim, Donggiun; Hopf, Amber; Salt, David E

2005-03-01

3

Cadmium hyperaccumulation and reproductive traits in natural Thlaspi caerulescens populations.  

PubMed

During the last decade, the metal hyperaccumulating plants have attracted considerable attention because of their potential use in decontamination of heavy metal contaminated soils. However, in most species, little is known regarding the function, the ecological and the evolutionary significances of hyperaccumulation. In our study, we investigated the parameters influencing the Cd concentration in plants as well as the biological implications of Cd hyperaccumulation in nine natural populations of Thlaspi caerulescens. First, we showed that Cd concentration in the plant was positively correlated with plant Zn, Fe, and Cu concentrations. This suggested that the physiological and/or molecular mechanisms for uptake, transport and/or accumulation of these four heavy metals interact with each other. Second, we specified a measure of Cd hyperaccumulation capacity by populations and showed that T. caerulescens plants originating from populations with high Cd hyperaccumulation capacity had better growth, by developing more and bigger leaves, taller stems, and produced more fruits and heavier seeds. These results suggest a tolerance/disposal role of Cd hyperaccumulation in this species. PMID:16435270

Basic, N; Keller, C; Fontanillas, P; Vittoz, P; Besnard, G; Galland, N

2006-01-01

4

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

Microsoft Academic Search

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

Rengasamy Boominathan; Pauline M. Doran

2003-01-01

5

Reciprocal grafting separates the roles of the root and shoot in zinc hyperaccumulation in Thlaspi caerulescens.  

PubMed

* The extreme phenotype of zinc (Zn) hyperaccumulation, which is found in several Brassicaceae species, is determined by mechanisms that promote elevated Zn tolerance and high Zn accumulation in shoots. * We used reciprocal grafting between a Zn hyperaccumulator, Thlaspi caerulescens, and a Zn nonaccumulator, Thlaspi perfoliatum, to determine the relative importance of roots and shoots in Zn hyperaccumulation and hypertolerance. * Leaves from plants with a T. perfoliatum rootstock and a T. caerulescens shoot scion did not hyperaccumulate Zn, whereas plants with a T. caerulescens rootstock and a T. perfoliatum shoot scion did hyperaccumulate Zn. However, although leaves from plants with a T. caerulescens rootstock and a T. perfoliatum shoot scion hyperaccumulated Zn, at high Zn loads these leaves showed significant symptoms of Zn toxicity, unlike leaves of self grafted T. caerulescens. * Hyperaccumulation of Zn in leaves of the hyperaccumulator T. caerulescens is pri-marily dictated by root processes. Further, the mechanisms controlling Zn hypertolerance in the hyperaccumulator T. caerulescens are driven primarily by shoot processes. PMID:19656301

de Guimarães, Marcelo A; Gustin, Jeffery L; Salt, David E

2009-10-01

6

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

PubMed Central

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

Milner, Matthew J.; Kochian, Leon V.

2008-01-01

7

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

Microsoft Academic Search

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

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

2003-01-01

8

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...

9

Hyperaccumulation of cadmium by hairy roots of Thlaspi caerulescens.  

PubMed

Hairy roots were used to investigate cadmium uptake by Thlaspi caerulescens, a metal hyperaccumulator plant with potential applications in phytoremediation and phytomining. Experiments were carried out in nutrient media under conditions supporting root growth. Accumulation of Cd in short-term (9-h) experiments varied with initial medium pH and increased after treating the roots with H(+)-ATPase inhibitor. The highest equilibrium Cd content measured in T. caerulescens roots was 62,800 microg g(-1) dry weight, or 6.3% dry weight, at a liquid Cd concentration of 3710 ppm. Cd levels in live T. caerulescens roots were 1.5- to 1.7-fold those in hairy roots of nonhyperaccumulator species exposed to the same Cd concentration, but similar to the Cd content of autoclaved T. caerulescens roots. The ability to grow at Cd concentrations of up to 100 ppm clearly distinguished T. caerulescens hairy roots from the nonhyperaccumulators. The specific growth rate of T. caerulescens roots was essentially unaffected by 20 to 50 ppm Cd in the culture medium; in contrast, N. tabacum roots turned dark brown at 20 ppm and growth was negligible. Up to 10,600 microg g(-1) dry weight Cd was accumulated by growing T. caerulescens hairy roots. Measurement of Cd levels in whole roots and in the cell wall fraction revealed significant differences in the responses of T. caerulescens and N. tabacum roots to 20 ppm Cd. Most metal was transported directly into the symplasm of N. tabacum roots within 3 days of exposure; in contrast, T. caerulescens roots stored virtually all of their Cd in the wall fraction for the first 7 to 10 days. This delay in transmembrane uptake may represent an important defensive strategy against Cd poisoning in T. caerulescens, allowing time for activation of intracellular mechanisms for heavy metal detoxification. PMID:10649235

Nedelkoska, T V; Doran, P M

2000-03-01

10

Hyperaccumulation of cadmium by hairy roots of Thlaspi caerulescens  

SciTech Connect

Hairy roots were used to investigate cadmium uptake by Thlaspi caerulescens, a metal hyperaccumulator plant with potential applications in phytoremediation and phytomining. Experiments were carried out in nutrient media under conditions supporting root growth. Accumulation of Cd in short-term (9-h) experiments varied with initial medium pH and increased after treating the roots with H{sup +}-ATPase inhibitor. The highest equilibrium Cd content measured in T. caerulescens roots was 62,800 {micro}g g{sup {minus}1} dry weight, or 6.3% dry weight, at a liquid Cd concentration of 3,710 ppm. Cd levels in live T. caerulescens roots were 1.5- to 1.7-fold those in hairy roots of nonhyperaccumulator species exposed to the same Cd concentration, but similar to the Cd content of auto-claved T. caerulescens roots. The ability to grow at Cd concentrations of up to 100 ppm clearly distinguished T. caerulescens hairy roots from the nonhyperaccumulators. The specific growth rate of T. caerulescens roots was essentially unaffected by 20 to 50 ppm Cd in the culture medium; in contrast, N. tabacum roots turned dark brown at 20 ppm and growth was negligible. Up to 10,600 {micro}g g{sup {minus}1} dry weight Cd was accumulated by growing T. caerulescens hairy roots. Measurement of Cd levels in while roots and in the cell wall fraction revealed significant differences in the responses of T. caerulescens and N. tabacum roots to 20 ppm Cd. Most metal was transported directly into the symplasm of N. tabacum roots within 3 days of exposure; in contrast, T. caerulescens roots stored virtually all of their Cd in the wall fraction for the first 7 to 10 days. This delay in transmembrane uptake may represent an important defensive strategy against Cd poisoning in T. caerulescens, allowing time for activation of intracellular mechanisms for heavy metal detoxification.

Nedelkoska, T.V.; Doran, P.M.

2000-03-05

11

Variations in plant metallothioneins: the heavy metal hyperaccumulator Thlaspi caerulescens as a study case  

Microsoft Academic Search

Plant metallothioneins (MTs) are extremely diverse and are thought to be involved in metal homeostasis or detoxification.\\u000a Thlaspi caerulescens is a model Zn\\/Cd hyperaccumulator and thus constitutes an ideal system to study the variability of these MTs. Two T. caerulescens cDNAs (accession: 665511; accession: 665515), that are highly homologous to type 1 and type 2 Arabidopsis thaliana MTs, have been

Nancy H. Roosens; Raphael Leplae; Catherine Bernard; Nathalie Verbruggen

2005-01-01

12

The molecular physiology of heavy metal transport in the Zn/Cd hyperaccumulator Thlaspi caerulescens  

PubMed Central

An integrated molecular and physiological investigation of the fundamental mechanisms of heavy metal accumulation was conducted in Thlaspi caerulescens, a Zn/Cd-hyperaccumulating plant species. A heavy metal transporter cDNA, ZNT1, was cloned from T. caerulescens through functional complementation in yeast and was shown to mediate high-affinity Zn2+ uptake as well as low-affinity Cd2+ uptake. It was found that this transporter is expressed at very high levels in roots and shoots of the hyperaccumulator. A study of ZNT1 expression and high-affinity Zn2+ uptake in roots of T. caerulescens and in a related nonaccumulator, Thlaspi arvense, showed that alteration in the regulation of ZNT1 gene expression by plant Zn status results in the overexpression of this transporter and in increased Zn influx in roots of the hyperaccumulating Thlaspi species. These findings yield insights into the molecular regulation and control of plant heavy metal and micronutrient accumulation and homeostasis, as well as provide information that will contribute to the advancement of phytoremediation by the future engineering of plants with improved heavy metal uptake and tolerance. PMID:10781104

Pence, Nicole S.; Larsen, Paul B.; Ebbs, Stephen D.; Letham, Deborah L. D.; Lasat, Mitch M.; Garvin, David F.; Eide, David; Kochian, Leon V.

2000-01-01

13

Multivariate analysis of protein profiles of metal hyperaccumulator Thlaspi caerulescens accessions.  

PubMed

Thlaspi caerulescens is increasingly acknowledged as one of the best models for studying metal hyperaccumulation in plants. In order to study the mechanisms underlying metal hyperaccumulation, we used proteomic profiling to identify differences in protein intensities among three T. caerulescens accessions with pronounced differences in tolerance, uptake and root to shoot translocation of Zn and Cd. Proteins were separated using two-dimensional electrophoresis and stained with SYPRO Orange. Intensity values and quality scores were obtained for each spot by using PDQuest software. Principal component analysis was used to test the separation of the protein profiles of the three plant accessions at various metal exposures, and to detect groups of proteins responsible for the differences. Spot sets representing individual proteins were analysed with the analysis of variance and non-parametric Kruskal-Wallis test. Clearest differences were seen among the Thlaspi accessions, while the effects of metal exposures were less pronounced. The 48 tentatively identified spots represent core metabolic functions (e.g. photosynthesis, nitrogen assimilation, carbohydrate metabolism) as well as putative signalling and regulatory functions. The possible roles of some of the proteins in heavy metal accumulation and tolerance are discussed. PMID:16691554

Tuomainen, Marjo H; Nunan, Naoise; Lehesranta, Satu J; Tervahauta, Arja I; Hassinen, Viivi H; Schat, Henk; Koistinen, Kaisa M; Auriola, Seppo; McNicol, Jim; Kärenlampi, Sirpa O

2006-06-01

14

SHOOT BIOMASS AND ZINC/CADMIUM UPTAKE FOR HYPERACCUMULATOR AND NON-ACCUMULATOR THLASPI SPECIES IN RESPONSE TO GROWTH ON A ZINC-DEFICIENT CALCAREOUS SOIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

In this study, the Zn/Cd hyperaccumulator, Thlaspi caerulescens and a related non-accumulator, Thlaspi arvense, were used to study shoot growth (dry matter production) and Zn and Cd uptake from a severely Zn-deficient calcareous soil supplemented with increasing amounts of Zn and Cd. Shoot dry matte...

15

Spatial distribution of cadmium in leaves of metal hyperaccumulating Thlaspi praecox using micro-PIXE.  

PubMed

* Localization of cadmium (Cd) and other elements was studied in the leaves of the field-collected cadmium/zinc (Cd/Zn) hyperaccumulator Thlaspi praecox from an area polluted with heavy metals near a lead mine and smelter in Slovenia, using micro-PIXE (proton-induced X-ray emission). * The samples were prepared using cryofixation. Quantitative elemental maps and average concentrations in whole-leaf cross-sections and selected tissues were obtained. * Cd was preferentially localized in the lower epidermis (820 microg g(-1) DW), vascular bundles and upper epidermis, whereas about twice the lower concentrations were found in the mesophyll. * Taking into account the large volume of the mesophyll compared with the epidermis, the mesophyll is indicated as a relatively large pool of Cd, possibly involved in Cd detoxification/dilution at the tissue and cellular level. PMID:18554265

Vogel-Mikus, Katarina; Regvar, Marjana; Mesjasz-Przyby?owicz, Jolanta; Przyby?owicz, Wojciech J; Simcic, Jure; Pelicon, Primoz; Budnar, Milos

2008-01-01

16

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

PubMed

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

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

17

Gene manipulation of a heavy metal hyperaccumulator species Thlaspi caerulescens L. via Agrobacterium-mediated transformation.  

PubMed

Thlaspi caerulescens L. is well known as a Zn/Cd hyperaccumulator. The genetic manipulation of T. caerulescens through transgenic technology can modify plant features for use in phytoremediation. Here, we describe the efficient transformation of T. caerulescens using Agrobacterium tumefaciens strain EHA105 harboring a binary vector pBI121 with the nptII gene as a selectable marker, the gus gene as a reporter and a foreign catalase gene. Based on the optimal concentration of growth regulators, the shoot cluster regeneration system via callus phase provided the basis of the genetic transformation in T. caerulescens. The key variables in transformation were examined, such as co-cultivation period and bacterial suspension density. Optimizing factors for T-DNA delivery resulted in kanamycin-resistant transgenic shoots with transformation efficiency more than 20%, proven by histochemical GUS assay and PCR analysis. Southern analysis of nptII and RT-PCR of catalase gene demonstrated that the foreign genes were integrated in the genome of transformed plantlets. Moreover, the activity of catalase enzyme in transgenic plants was obviously higher than in wild-type plants. This method offers new prospects for the genetic engineering of this important hyperaccumulator species. PMID:18427996

Guan, Zi Qiu; Chai, Tuan Yao; Zhang, Yu Xiu; Xu, Jin; Wei, Wei; Han, Lu; Cong, Lin

2008-09-01

18

Hyperaccumulation of cadmium and zinc in Thlaspi caerulescens and Arabidopsis halleri at the leaf cellular level.  

PubMed

Vacuolar compartmentalization or cell wall binding in leaves could play a major role in hyperaccumulation of heavy metals. However, little is known about the physiology of intracellular cadmium (Cd) sequestration in plants. We investigated the role of the leaf cells in allocating metal in hyperaccumulating plants by measuring short-term (109)Cd and (65)Zn uptake in mesophyll protoplasts of Thlaspi caerulescens "Ganges" and Arabidopsis halleri, both hyperaccumulators of zinc (Zn) and Cd, and T. caerulescens "Prayon," accumulating Cd at a lower degree. The effects of low temperature, several divalent cations, and pre-exposure of the plants to metals were investigated. There was no significant difference between the Michaelis-Menten kinetic constants of the three plants. It indicates that differences in metal uptake cannot be explained by different constitutive transport capacities at the leaf protoplast level and that plasma and vacuole membranes of mesophyll cells are not responsible for the differences observed in heavy metal allocation. This suggests the existence of regulation mechanisms before the plasma membrane of leaf mesophyll protoplasts. However, pre-exposure of the plants to Cd induced an increase in Cd accumulation in protoplasts of "Ganges," whereas it decreased Cd accumulation in A. halleri protoplasts, indicating that Cd-permeable transport proteins are differentially regulated. The experiment with competitors has shown that probably more than one single transport system is carrying Cd in parallel into the cell and that in T. caerulescens "Prayon," Cd could be transported by a Zn and Ca pathway, whereas in "Ganges," Cd could be transported mainly by other pathways. PMID:14730081

Cosio, Claudia; Martinoia, Enrico; Keller, Catherine

2004-02-01

19

QTL analysis of cadmium and zinc accumulation in the heavy metal hyperaccumulator Thlaspi caerulescens.  

PubMed

Thlaspi caerulescens (Tc; 2n = 14) is a natural Zn, Cd and Ni hyperaccumulator species belonging to the Brassicaceae family. It shares 88% DNA identity in the coding regions with Arabidopsis thaliana (At) (Rigola et al. 2006). Although the physiology of heavy metal (hyper)accumulation has been intensively studied, the molecular genetics are still largely unexplored. We address this topic by constructing a genetic map based on AFLP markers and expressed sequence tags (ESTs). To establish a genetic map, an F(2) population of 129 individuals was generated from a cross between a plant from a Pb/Cd/Zn-contaminated site near La Calamine, Belgium, and a plant from a comparable site near Ganges (GA), France. These two accessions show different degrees of Zn and, particularly, Cd accumulation. We analyzed 181 AFLP markers (of which 4 co-dominant) and 13 co-dominant EST sequences-based markers and mapped them to seven linkage groups (LGs), presumably corresponding to the seven chromosomes of T. caerulescens. The total length of the genetic map is 496 cM with an average density of one marker every 2.5 cM. This map was used for Quantitative Trait Locus (QTL) mapping in the F(2). For Zn as well as Cd concentration in root we mapped two QTLs. Three QTLs and one QTL were mapped for Zn and Cd concentration in shoot, respectively. These QTLs explain 23.8-60.4% of the total variance of the traits measured. We found only one common locus (LG6) for Zn and Cd (concentration in root) and one common locus for shoot and root concentrations of Zn (LG1) and of Cd (LG3). For all QTLs, the GA allele increased the trait value except for two QTLs for Zn accumulation in shoot (LG1 and LG4) and one for Zn concentration in root (LG1). PMID:16850314

Deniau, A X; Pieper, B; Ten Bookum, W M; Lindhout, P; Aarts, M G M; Schat, H

2006-09-01

20

Cellular Compartmentation of Zinc in Leaves of the Hyperaccumulator Thlaspi caerulescens1  

PubMed Central

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

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

1999-01-01

21

Physiological Characterization of Root Zn2+ Absorption and Translocation to Shoots in Zn Hyperaccumulator and Nonaccumulator Species of Thlaspi.  

PubMed Central

Radiotracer techniques were employed to characterize 65Zn2+ influx into the root symplasm and translocation to the shoot in Thlaspi caerulescens, a Zn hyperaccumulator, and Thlaspi arvense, a nonaccumulator. A protocol was developed that allowed us to quantify unidirectional 65Zn2+ influx across the root-cell plasma membrane (20 min of radioactive uptake followed by 15 min of desorption in a 100 [mu]M ZnCl2 + 5 mM CaCl2 solution). Concentration-dependent Zn2+ influx in both Thlaspi species yielded nonsaturating kinetic curves that could be resolved into linear and saturable components. The linear kinetic component was shown to be cell-wall-bound Zn2+ remaining in the root after desorption, and the saturable component was due to Zn2+ influx across the root-cell plasma membrane. This saturable component followed Michaelis-Menten kinetics, with similar apparent Michaelis constant values for T. caerulescens and T. arvense (8 and 6 [mu]M, respectively). However, the maximum initial velocity for Zn2+ influx in T. caerulescens root cells was 4.5-fold higher than for T. arvense, indicating that enhanced absorption into the root is one of the mechanisms involved in Zn hyperaccumulation. After 96 h 10-fold more 65Zn was translocated to the shoot of T. caerulescens compared with T. arvense. This indicates that transport sites other than entry into the root symplasm are also stimulated in T. caerulescens. We suggest that although increased root Zn2+ influx is a significant component, transport across the plasma membrane and tonoplast of leaf cells must also be critical sites for Zn hyperaccumulation in T. caerulescens. PMID:12226473

Lasat, M. M.; Baker, AJM.; Kochian, L. V.

1996-01-01

22

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

Microsoft Academic Search

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

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

23

Shoot biomass and zinc\\/cadmium uptake for hyperaccumulator and non-accumulator Thlaspi species in response to growth on a zinc-deficient calcareous soil  

Microsoft Academic Search

Thlaspi caerulescens is one of the best-known heavy metal hyperaccumulating plant species. It exhibits the ability to extract metals from soils and accumulates them in shoots at extremely high concentrations, particularly zinc (Zn) and cadmium (Cd). Using T. caerulescens (J. and C. Presl, ecotype Prayon) and a closely related non-accumulator species T. arvense, greenhouse experiments were carried out to study

Levent Ozturk; Sema Karanlik; Faruk Ozkutlu; Ismail Cakmak; Leon V. Kochian

2003-01-01

24

Complexation and Toxicity of Copper in Higher Plants. II. Different Mechanisms for Copper versus Cadmium Detoxification in the Copper-Sensitive Cadmium\\/Zinc Hyperaccumulator Thlaspi caerulescens (Ganges Ecotype)1(OA)  

Microsoft Academic Search

The cadmium\\/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which is a problem for phytoremediation of soils with mixed contamination. Cu levels in T. caerulescens grown with 10 mM Cu2+ remained in the nonaccumulator range (,50 ppm), and most individuals were as sensitive toward Cu as the related nonaccumulator Thlaspi fendleri. Obviously, hyperaccumulation and metal resistance are highly

Ana Mijovilovich; Barbara Leitenmaier; Wolfram Meyer-Klaucke; Peter M. H. Kroneck; Birgit Gotz; Hendrik Kupper

25

Cadmium uptake and sequestration kinetics in individual leaf cell protoplasts of the Cd/Zn hyperaccumulator Thlaspi caerulescens.  

PubMed

Hyperaccumulators store accumulated metals in the vacuoles of large leaf epidermal cells (storage cells). For investigating cadmium uptake, we incubated protoplasts obtained from leaves of Thlaspi caerulescens (Ganges ecotype) with a Cd-specific fluorescent dye. A fluorescence kinetic microscope was used for selectively measuring Cd-uptake and photosynthesis in different cell types, so that physical separation of cell types was not necessary. Few minutes after its addition, cadmium accumulated in the cytoplasm before its transport into the vacuole. This demonstrated that vacuolar sequestration is the rate-limiting step in cadmium uptake into protoplasts of all leaf cell types. During accumulation in the cytoplasm, Cd-rich vesicle-like structures were observed. Cd uptake rates into epidermal storage cells were higher than into standard-sized epidermal cells and mesophyll cells. This shows that the preferential heavy metal accumulation in epidermal storage cells, previously observed for several metals in intact leaves of various hyperaccumulator species, is due to differences in active metal transport and not differences in passive mechanisms like transpiration stream transport or cell wall adhesion. Combining this with previous studies, it seems likely that the transport steps over the plasma and tonoplast membranes of leaf epidermal storage cells are driving forces behind the hyperaccumulation phenotype. PMID:20880204

Leitenmaier, Barbara; Küpper, Hendrik

2011-02-01

26

Complexation of cadmium in seeds and vegetative tissues of the cadmium hyperaccumulator Thlaspi praecox as studied by X-ray absorption spectroscopy  

Microsoft Academic Search

The cadmium hyperaccumulator Thlaspi praecox Wulfen (Brassicaceae) can accumulate unusually high amounts of Cd (>1,000 ?g g?1 dry weight) in its seeds without drastically affecting seed viability. As embryonic tissues are the most sensitive to Cd\\u000a toxicity, the aim of this study was to investigate the Cd coordination and ligand environment in seeds of field collected\\u000a T. praecox using extended X-ray absorption

Katarina Vogel-Mikuš; Iztok Ar?on; Alojz Kodre

2010-01-01

27

Effect of microbial siderophore DFO-B on Cd accumulation by Thlaspi caerulescens hyperaccumulator in the presence of zeolite.  

PubMed

Hyperaccumulators are grown in contaminated soil and water in order that contaminants are taken up and accumulated. Transport of metals from soil to plant is initially dependent on the solubility and mobility of metals in soil solution which is controlled by soil and metal properties and plant physiology. Complexation with organic and inorganic ligands may increase mobility and availability of metals for plants. In this work the influence of desferrioxamine-B (DFO-B), which naturally is produced in the rhizosphere, and zeolite on Cd accumulation in root and shoot of Thlaspi caerulescens (Cd hyperaccumulator) was investigated. Plants were grown in pots with clean quartz sand, amended with 1% zeolite; treatment solutions included 0, 10, and 100 ?M Cd and 70 ?M DFO-B. Addition of zeolite to the quartz sand significantly reduced Cd concentration in plant tissues and translocation from root to shoot. On contrary, DFO-B considerably enhanced Cd sorption by roots and translocation to aerial part of plants. Treating the plants with zeolite and DFO-B together at 10 ?M Cd resulted in reduction of the bioaccumulation factor but enhancement of Cd translocation from root to shoot at the rate of 13%. In contrast, at 100 ?M Cd in the solution both bioaccumulation and translocation factors decreased. Total metal accumulation as a key factor for evaluating the efficiency of phytoremediation was highly influenced by treatments. Presence of zeolite in pots significantly decreased total Cd accumulation by plants, whereas, DFO-B clearly enhanced it. PMID:22572166

Karimzadeh, Lotfollah; Heilmeier, Hermann; Merkel, Broder J

2012-07-01

28

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

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

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

1998-01-01

29

Root-to-shoot long-distance circulation of nicotianamine and nicotianamine-nickel chelates in the metal hyperaccumulator Thlaspi caerulescens.  

PubMed

Plant metal hyperaccumulator species are widely used as models to unravel the heavy metal tolerance and hyperaccumulation mechanisms. Thlaspi caerulescens is capable of tolerating and hyperaccumulating Zn, Cd, and Ni. A search for factors involved in the cellular tolerance to Ni, based on yeast screens, led to isolation of a cDNA encoding a functional nicotianamine (NA) synthase (NAS). The T. caerulescens genome appears to contain a single copy of the NAS gene named TcNAS whose expression is restricted to the leaves. The analysis of dose-response and time-course Ni treatments have revealed that the exposure to Ni triggers the accumulation of NA in the roots. Because neither TcNAS expression nor NAS activity were detected in the roots, the NA accumulation in roots is most probably the result of its translocation from the leaves. Once in the roots, NA, together with Ni, is subsequently found in the xylem, for redirection to the aerial parts. Using liquid chromatography coupled to inductively coupled plasma or electrospray ionization mass spectrometry, it has been shown that part of the Ni is translocated as a stable Ni-NA complex in the xylem sap. This circulation of NA, Ni, and NA-Ni chelates is absent in the non-tolerant non-hyperaccumulator related species T. arvense. Taken together, the results provide direct physiological and chemical evidence for NA and NA-heavy metal complex translocation in a hyperaccumulator species. PMID:17079698

Mari, Stéphane; Gendre, Delphine; Pianelli, Katia; Ouerdane, Laurent; Lobinski, Ryszard; Briat, Jean-François; Lebrun, Michel; Czernic, Pierre

2006-01-01

30

Identification of Thlaspi caerulescens genes that may be involved in heavy metal hyperaccumulation and tolerance. Characterization of a novel heavy metal transporting ATPase.  

PubMed

Thlaspi caerulescens is a heavy metal hyperaccumulator plant species that is able to accumulate extremely high levels of zinc (Zn) and cadmium (Cd) in its shoots (30,000 microg g(-1) Zn and 10,000 microg g(-1) 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 soils. In this study, we report on the results of a yeast (Saccharomyces cerevisae) complementation screen aimed at identifying candidate heavy metal tolerance genes in T. caerulescens. A number of Thlaspi genes that conferred Cd tolerance to yeast were identified, including possible metal-binding ligands from the metallothionein gene family, and a P-type ATPase that is a member of the P1B subfamily of purported heavy metal-translocating ATPases. A detailed characterization of the Thlaspi heavy metal ATPase, TcHMA4, demonstrated that it mediates yeast metal tolerance via active efflux of a number of different heavy metals (Cd, Zn, lead [Pb], and copper [Cu]) out of the cell. However, in T. caerulescens, based on differences in tissue-specific and metal-responsive expression of this transporter compared with its homolog in Arabidopsis (Arabidopsis thaliana), we suggest that it may not be involved in metal tolerance. Instead, we hypothesize that it may play a role in xylem loading of metals and thus could be a key player in the hyperaccumulation phenotype expressed in T. caerulescens. Additionally, evidence is presented showing that the C terminus of the TcHMA4 protein, which contains numerous possible heavy metal-binding His and Cys repeats residues, participates in heavy metal binding. When partial peptides from this C-terminal domain were expressed in yeast, they conferred an extremely high level of Cd tolerance and Cd hyperaccumulation. The possibilities for enhancing the metal tolerance and phytoremediation potential of higher plants via expression of these metal-binding peptides are also discussed. PMID:15516513

Papoyan, Ashot; Kochian, Leon V

2004-11-01

31

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...

32

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

PubMed Central

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

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

33

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

SciTech Connect

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.

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

2009-01-23

34

Complexation and Toxicity of Copper in Higher Plants. II. Different Mechanisms for Copper versus Cadmium Detoxification in the Copper-Sensitive Cadmium/Zinc Hyperaccumulator Thlaspi caerulescens (Ganges Ecotype)1[OA  

PubMed Central

The cadmium/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which is a problem for phytoremediation of soils with mixed contamination. Cu levels in T. caerulescens grown with 10 ?m Cu2+ remained in the nonaccumulator range (<50 ppm), and most individuals were as sensitive toward Cu as the related nonaccumulator Thlaspi fendleri. Obviously, hyperaccumulation and metal resistance are highly metal specific. Cu-induced inhibition of photosynthesis followed the “sun reaction” type of damage, with inhibition of the photosystem II reaction center charge separation and the water-splitting complex. A few individuals of T. caerulescens were more Cu resistant. Compared with Cu-sensitive individuals, they recovered faster from inhibition, at least partially by enhanced repair of chlorophyll-protein complexes but not by exclusion, since the content of Cu in their shoots was increased by about 25%. Extended x-ray absorption fine structure (EXAFS) measurements on frozen-hydrated leaf samples revealed that a large proportion of Cu in T. caerulescens is bound by sulfur ligands. This is in contrast to the known binding environment of cadmium and zinc in the same species, which is dominated by oxygen ligands. Clearly, hyperaccumulators detoxify hyperaccumulated metals differently compared with nonaccumulated metals. Furthermore, strong features in the Cu-EXAFS spectra ascribed to metal-metal contributions were found, in particular in the Cu-resistant specimens. Some of these features may be due to Cu binding to metallothioneins, but a larger proportion seems to result from biomineralization, most likely Cu(II) oxalate and Cu(II) oxides. Additional contributions in the EXAFS spectra indicate complexation of Cu(II) by the nonproteogenic amino acid nicotianamine, which has a very high affinity for Cu(II) as further characterized here. PMID:19692532

Mijovilovich, Ana; Leitenmaier, Barbara; Meyer-Klaucke, Wolfram; Kroneck, Peter M.H.; Götz, Birgit; Küpper, Hendrik

2009-01-01

35

Complexation and toxicity of copper in higher plants. II. Different mechanisms for copper versus cadmium detoxification in the copper-sensitive cadmium/zinc hyperaccumulator Thlaspi caerulescens (Ganges Ecotype).  

PubMed

The cadmium/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which is a problem for phytoremediation of soils with mixed contamination. Cu levels in T. caerulescens grown with 10 microm Cu(2+) remained in the nonaccumulator range (<50 ppm), and most individuals were as sensitive toward Cu as the related nonaccumulator Thlaspi fendleri. Obviously, hyperaccumulation and metal resistance are highly metal specific. Cu-induced inhibition of photosynthesis followed the "sun reaction" type of damage, with inhibition of the photosystem II reaction center charge separation and the water-splitting complex. A few individuals of T. caerulescens were more Cu resistant. Compared with Cu-sensitive individuals, they recovered faster from inhibition, at least partially by enhanced repair of chlorophyll-protein complexes but not by exclusion, since the content of Cu in their shoots was increased by about 25%. Extended x-ray absorption fine structure (EXAFS) measurements on frozen-hydrated leaf samples revealed that a large proportion of Cu in T. caerulescens is bound by sulfur ligands. This is in contrast to the known binding environment of cadmium and zinc in the same species, which is dominated by oxygen ligands. Clearly, hyperaccumulators detoxify hyperaccumulated metals differently compared with nonaccumulated metals. Furthermore, strong features in the Cu-EXAFS spectra ascribed to metal-metal contributions were found, in particular in the Cu-resistant specimens. Some of these features may be due to Cu binding to metallothioneins, but a larger proportion seems to result from biomineralization, most likely Cu(II) oxalate and Cu(II) oxides. Additional contributions in the EXAFS spectra indicate complexation of Cu(II) by the nonproteogenic amino acid nicotianamine, which has a very high affinity for Cu(II) as further characterized here. PMID:19692532

Mijovilovich, Ana; Leitenmaier, Barbara; Meyer-Klaucke, Wolfram; Kroneck, Peter M H; Götz, Birgit; Küpper, Hendrik

2009-10-01

36

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...

37

Tissue- and Age-Dependent Differences in the Complexation of Cadmium and Zinc in the Cadmium/Zinc Hyperaccumulator Thlaspi caerulescens (Ganges Ecotype) Revealed by X-Ray Absorption Spectroscopy1[w  

PubMed Central

Extended x-ray absorption fine structure measurements were performed on frozen hydrated samples of the cadmium (Cd)/zinc (Zn) hyperaccumulator Thlaspi caerulescens (Ganges ecotype) after 6 months of Zn2+ treatment with and without addition of Cd2+. Ligands depended on the metal and the function and age of the plant tissue. In mature and senescent leaves, oxygen ligands dominated. This result combined with earlier knowledge about metal compartmentation indicates that the plants prefer to detoxify hyperaccumulated metals by pumping them into vacuoles rather than to synthesize metal specific ligands. In young and mature tissues (leaves, petioles, and stems), a higher percentage of Cd was bound by sulfur (S) ligands (e.g. phytochelatins) than in senescent tissues. This may indicate that young tissues require strong ligands for metal detoxification in addition to the detoxification by sequestration in the epidermal vacuoles. Alternatively, it may reflect the known smaller proportion of epidermal metal sequestration in younger tissues, combined with a constant and high proportion of S ligands in the mesophyll. In stems, a higher proportion of Cd was coordinated by S ligands and of Zn by histidine, compared with leaves of the same age. This may suggest that metals are transported as stable complexes or that the vacuolar oxygen coordination of the metals is, like in leaves, mainly found in the epidermis. The epidermis constitutes a larger percentage of the total volume in leaves than in stems and petioles. Zn-S interaction was never observed, confirming earlier results that S ligands are not involved in Zn resistance of hyperaccumulator plants. PMID:14966248

Küpper, Hendrik; Mijovilovich, Ana; Meyer-Klaucke, Wolfram; Kroneck, Peter M.H.

2004-01-01

38

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

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

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

39

Potential use of metal hyperaccumulators  

SciTech Connect

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.

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

1996-12-31

40

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...

41

Response of Thlaspi caerulescens to Nitrogen, Phosphorus and Sulfur Fertilisation  

Microsoft Academic Search

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

Sirguey Catherine; Schwartz Christophe; Morel Jean Louis

2006-01-01

42

POTENTIAL FOR GENETIC IMPROVEMENT OF THLASPI CAERULESCENS FOR PHYTOREMEDIATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thlaspi caerulescens has excellent potential to be used for remediation of zinc and cadmium polluted soils. Although plants of this species have been found to consistently hyperaccumulate cadmium and zinc, the levels of cadmium and zinc that individual plants accumulate depend on their genotype and...

43

A comparison of the Thlaspi caerulescens and Thlaspi arvense shoot transcriptomes.  

PubMed

Whole-genome transcriptome profiling is revealing how biological systems are regulated at the transcriptional level. This study reports the development of a robust method to profile and compare the transcriptomes of two nonmodel plant species, Thlaspi caerulescens, a zinc (Zn) hyperaccumulator, and Thlaspi arvense, a nonhyperaccumulator, using Affymetrix Arabidopsis thaliana ATH1-121501 GeneChip arrays (Affymetrix, Santa Clara, CA, USA). Transcript abundance was quantified in the shoots of agar- and compost-grown plants of both species. Analyses were optimized using a genomic DNA (gDNA)-based probe-selection strategy based on the hybridization efficiency of Thlaspi gDNA with corresponding A. thaliana probes. In silico alignments of GeneChip probes with Thlaspi gene sequences, and quantitative real-time PCR, confirmed the validity of this approach. Approximately 5000 genes were differentially expressed in the shoots of T. caerulescens compared with T. arvense, including genes involved in Zn transport and compartmentalization. Future functional analyses of genes identified as differentially expressed in the shoots of these closely related species will improve our understanding of the molecular mechanisms of Zn hyperaccumulation. PMID:16608451

Hammond, John P; Bowen, Helen C; White, Philip J; Mills, Victoria; Pyke, Kevin A; Baker, Alan J M; Whiting, Steven N; May, Sean T; Broadley, Martin R

2006-01-01

44

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

E-print Network

in arsenic detoxification. Abstract Pteris vittata (Chinese brake fern) has potential for phytoremediation to be constitutive in nature as in zinc and cadmium hyperaccumulators Arabidopsis halleri and Thlaspi caerulescens

Ma, Lena

45

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...

46

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

Microsoft Academic Search

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

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

2009-01-01

47

The potential of Thlaspi caerulescens for phytoremediation of contaminated soils  

Microsoft Academic Search

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

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

1998-01-01

48

EXPRESSION PROFILING OF ZN AND OTHER METAL RELATED GENES IN THLASPI CAERULESCENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous research has shown that Thlaspi caerulescens is able to hyperaccumulate as much as 30,000 ppm zinc and 10,000 ppm cadmium in its shoots. In an attempt to better understand the ability of this plant to tolerate and accumulate such high levels of toxic metals, we looked at the expression of g...

49

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

Microsoft Academic Search

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

Saoussen Benzarti; Helmi Hamdi; Shino Mohri; Yoshiro Ono

2010-01-01

50

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

SciTech Connect

'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.'

Salt, D.

1998-06-01

51

Potential of Thlaspi caerulescens for Cadmium Phytoremediation: Comparison of Two Representative Soil Types in Japan under Different Planting Frequencies  

Microsoft Academic Search

To assess the potential of the Cd hyperaccumulator Thlaspi caerulescens (Ganges ecotype) for Cd phytoremediation in Japan, we compared the changes in the soil Cd concentration between a Fluvisol and an Andosol and the efficiency of Cd removal under different planting frequencies in a pot experiment. The soils were artificially contaminated with Cd(NO3)2 to the level of about 5 mg

Yuko Nishiyama; Junta Yanai; Takashi Kosaki

2005-01-01

52

Metal Hyperaccumulation Armors Plants against Disease  

PubMed Central

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

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

2010-01-01

53

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

PubMed

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

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

2007-01-01

54

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

SciTech Connect

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.

Salt, David E.

1999-06-01

55

Plant Cd2+ and Zn2+ status effects on root and shoot heavy metal accumulation in Thlaspi caerulescens.  

PubMed

* In this study we address the impact of changes in plant heavy metal, (i.e. zinc (Zn) and cadmium (Cd)) status on metal accumulation in the Zn/Cd hyperaccumulator, Thlaspi caerulescens. * Thlaspi caerulescens plants were grown hydroponically on both high and low Zn and Cd regimes and whole-shoot and -root metal accumulation, and root (109)Cd(2+) influx were determined. * High-Zn-grown (500 microm Zn) plants were found to be more Cd-tolerant than plants grown in standard Zn conditions (1 microm Zn). Furthermore, shoot Cd accumulation was significantly greater in the high-Zn-grown plants. A positive correlation was also found between shoot Zn accumulation and increased plant Cd status. Radiotracer (109)Cd root flux experiments demonstrated that high-Zn-grown plants maintained significantly higher root Cd(2+) influx than plants grown on 1 microm Zn. It was also found that both nickel (Ni) and copper (Cu) shoot accumulation were stimulated by high plant Zn status, while manganese (Mn) accumulation was not affected. * A speculative model is presented to explain these findings, suggesting that xylem loading may be one of the key sites responsible for the hyperaccumulation of Zn and Cd accumulation in Thlaspi caerulescens. PMID:17547666

Papoyan, Ashot; Piñeros, Miguel; Kochian, Leon V

2007-01-01

56

Development, Characterization, and Application of a Cadmium-Selective Microelectrode for the Measurement of Cadmium Fluxes in Roots of Thlaspi Species and Wheat  

Microsoft Academic Search

AC d 21-selective vibrating microelectrode was constructed using a neutral carrier-based Cd ionophore to investigate ion-transport processes along the roots of wheat (Triticum aestivum L.) and two species of Thlaspi, one a Zn\\/Cd hyperaccumulator and the other a related nonaccumulator. In simple Cd(NO3)2 solutions, the elec- trode exhibited a Nernstian response in solutions with Cd21 activ- ities as low as

Miguel A. Pineros; Jon E. Shaff; Leon V. Kochian

1998-01-01

57

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

PubMed

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

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

2003-01-01

58

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

Microsoft Academic Search

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

Jeffrey Munn; Mary January; Teresa J. Cutright

2008-01-01

59

Response of Thlaspi caerulescens to nitrogen, phosphorus and sulfur fertilisation.  

PubMed

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 an agricultural soil and on a contaminated soil from the vicinity of a former Pb/Zn smelter. The nitrogen (N) treatment consisted of 4 levels (0, 11, 21.5 and 31 mg N kg(-1) dry soil (DS)) added as NH4NO3. The highest N treatment was combined with 4 levels of phosphorus (P) (0, 20, 40 and 80 mg P kg(-1) DS as KH2PO4) and sulfur (S) additions (0, 10, 20 and 30 mg S kg(-1) DS as MgSO4). The highest N fertilisation contributed significantly to enhance biomass production of T. caerulescens and to decrease the concentration of Cd and Zn in the biomass. At constant N addition, P supply did not affect metal extraction by T. caerulescens but negatively affected plant health. Sulfur supply slightly increased phytoextraction of Cd. Our results show that N and S fertilisation might interact but further investigations on the effect of such interaction on Cd extraction efficiency are needed. PMID:16924963

Catherine, Sirguey; Christophe, Schwartz; Louis, Morel Jean

2006-01-01

60

Distribution of cadmium in leaves of Thlaspi caerulescens.  

PubMed

Knowledge of the intracellular distribution of Cd in leaves is necessary in order to understand the mechanisms of hyperaccumulation in Thlaspi caerulescens. Ganges and Prayon, two ecotypes accumulating Cd to different levels, were grown in nutrient medium containing varying concentrations (0, 5, 10, 50, and 100 microM) of Cd. Several different approaches were combined in this study to (i) validate the results obtained by a specific method and (ii) establish the link between observations and measurements performed at different scales. In both ecotypes, Cd, localized by autoradiography, was found mainly at the edges of the leaves, but also in points of higher concentration spread over the whole limb surface. This localization was clearly correlated with the necrotic spots observed on Prayon leaves. Scanning electron microscopy coupled with energy dispersive X-ray microanalysis (cryo-SEM-EDXMA) and tissue fractionation (apoplasm, cell walls, mesophyll protoplasts, and lower epidermis) showed that Cd had similar patterns of distribution in leaf cells of both ecotypes. Cadmium was found both inside the cells and in the cell walls, mainly in the large epidermal cells but also in small epidermal cells. All the methods used agreed well and the results indicated that metal storage in the plants studied involves more than one compartment and that Cd is stored principally in the less metabolically active parts of leaf cells. PMID:15642714

Cosio, Claudia; DeSantis, Laura; Frey, Beat; Diallo, Saliou; Keller, Catherine

2005-02-01

61

Nickel and zinc isotope fractionation in hyperaccumulating and nonaccumulating plants.  

PubMed

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

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

2014-10-21

62

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

PubMed

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

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

63

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

PubMed Central

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 LC×LE 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

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

2010-01-01

64

Comparative transcriptome analysis of the metal hyperaccumulator Noccaea caerulescens  

PubMed Central

The metal hyperaccumulator Noccaea caerulescens is an established model to study the adaptation of plants to metalliferous soils. Various comparators have been used in these studies. The choice of suitable comparators is important and depends on the hypothesis to be tested and methods to be used. In high-throughput analyses such as microarray, N. caerulescens has been compared to non-tolerant, non-accumulator plants like Arabidopsis thaliana or Thlaspi arvense rather than to the related hypertolerant or hyperaccumulator plants. An underutilized source is N. caerulescens populations with considerable variation in their capacity to accumulate and tolerate metals. Whole transcriptome sequencing (RNA-Seq) is revealing interesting variation in their gene expression profiles. Combining physiological characteristics of N. caerulescens accessions with their RNA-Seq has a great potential to provide detailed insight into the underlying molecular mechanisms, including entirely new gene products. In this review we will critically consider comparative transcriptome analyses carried out to explore metal hyperaccumulation and hypertolerance of N. caerulescens, and demonstrate the potential of RNA-Seq analysis as a tool in evolutionary genomics. PMID:24904610

Halimaa, Pauliina; Blande, Daniel; Aarts, Mark G. M.; Tuomainen, Marjo; Tervahauta, Arja; Kärenlampi, Sirpa

2014-01-01

65

Comparative transcriptome analysis of the metal hyperaccumulator Noccaea caerulescens.  

PubMed

The metal hyperaccumulator Noccaea caerulescens is an established model to study the adaptation of plants to metalliferous soils. Various comparators have been used in these studies. The choice of suitable comparators is important and depends on the hypothesis to be tested and methods to be used. In high-throughput analyses such as microarray, N. caerulescens has been compared to non-tolerant, non-accumulator plants like Arabidopsis thaliana or Thlaspi arvense rather than to the related hypertolerant or hyperaccumulator plants. An underutilized source is N. caerulescens populations with considerable variation in their capacity to accumulate and tolerate metals. Whole transcriptome sequencing (RNA-Seq) is revealing interesting variation in their gene expression profiles. Combining physiological characteristics of N. caerulescens accessions with their RNA-Seq has a great potential to provide detailed insight into the underlying molecular mechanisms, including entirely new gene products. In this review we will critically consider comparative transcriptome analyses carried out to explore metal hyperaccumulation and hypertolerance of N. caerulescens, and demonstrate the potential of RNA-Seq analysis as a tool in evolutionary genomics. PMID:24904610

Halimaa, Pauliina; Blande, Daniel; Aarts, Mark G M; Tuomainen, Marjo; Tervahauta, Arja; Kärenlampi, Sirpa

2014-01-01

66

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

SciTech Connect

'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.'

Salt, D.E.

1997-10-28

67

Organic acid complexation, heavy metal distribution and the effect of ATPase inhibition in hairy roots of hyperaccumulator plant species.  

PubMed

Heavy metal uptake and distribution were investigated in hairy roots of the Cd hyperaccumulator, Thlaspi caerulescens, and the Ni hyperaccumulator, Alyssum bertolonii. Hairy roots of both species contained high constitutive levels of citric, malic and malonic acids. After treatment with 20 ppm Cd or 25 ppm Ni, about 13% of the total Cd in T. caerulescens roots and 28% of the total Ni in A. bertolonii were associated with organic acids. T. caerulescens and A. bertolonii hairy roots remained healthy and grew well at high concentrations of Cd and Ni, respectively, whereas hairy roots of the non-hyperaccumulator, Nicotiana tabacum, did not. Most of the Cd in T. caerulescens and N. tabacum roots was localised in the cell walls. In contrast, 85-95% of the Ni in A. bertolonii and N. tabacum was associated with the symplasm. Growth of T. caerulescens and A. bertolonii hairy roots was severely reduced in the presence of diethylstilbestrol (DES), an inhibitor of plasma membrane H(+)-ATPase. Treatment with DES increased the concentration of Cd in the symplasm of T. caerulescens about 6-fold with retention of root viability, whereas viability and Ni transport across the plasma membrane were both reduced in A. bertolonii. These results suggest that the mechanisms of Cd tolerance and hyperaccumulation in T. caerulescens hairy roots are capable of withstanding the effects of plasma membrane depolarisation, whereas Ni tolerance and hyperaccumulation in A. bertolonii hairy roots are not. PMID:12568742

Boominathan, Rengasamy; Doran, Pauline M

2003-03-01

68

Construction of a genetic linkage map of Thlaspi caerulescens and quantitative trait loci analysis of zinc accumulation.  

PubMed

Zinc (Zn) hyperaccumulation seems to be a constitutive species-level trait in Thlaspi caerulescens. When compared under conditions of equal Zn availability, considerable variation in the degree of hyperaccumulation is observed among accessions originating from different soil types. This variation offers an excellent opportunity for further dissection of the genetics of this trait. A T. caerulescens intraspecific cross was made between a plant from a nonmetallicolous accession [Lellingen (LE)], characterized by relatively high Zn accumulation, and a plant from a calamine accession [La Calamine (LC)], characterized by relatively low Zn accumulation. Zinc accumulation in roots and shoots segregated in the F3 population. This population was used to construct an LE/LC amplified fragment length polymorphism (AFLP)-based genetic linkage map and to map quantitative trait loci (QTL) for Zn accumulation. Two QTL were identified for root Zn accumulation, with the trait-enhancing alleles being derived from each of the parents, and explaining 21.7 and 16.6% of the phenotypic variation observed in the mapping population. Future development of more markers, based on Arabidopsis orthologous genes localized in the QTL regions, will allow fine-mapping and map-based cloning of the genes underlying the QTL. PMID:16539600

Assunção, Ana G L; Pieper, Bjorn; Vromans, Jaap; Lindhout, Pim; Aarts, Mark G M; Schat, Henk

2006-01-01

69

Three new arsenic hyperaccumulating ferns  

Microsoft Academic Search

Phytoremediation, an emerging, plant-based technology for the removal of toxic contaminants from soil and water, has been receiving increased attention. The prerequisite for successful phytoremediation is the existence of hyperaccumulator plants. Designed to search for new arsenic (As) hyperaccumulators, an experiment was conducted under greenhouse conditions in a completely randomized design with four replications. This experiment identified Pteris biaurita L.,

Mrittunjai Srivastava; Lena Q. Ma; Jorge Antonio Gonzaga Santos

2006-01-01

70

Molecular mechanisms of metal hyperaccumulation in plants.  

PubMed

Metal hyperaccumulator plants accumulate and detoxify extraordinarily high concentrations of metal ions in their shoots. Metal hyperaccumulation is a fascinating phenomenon, which has interested scientists for over a century. Hyperaccumulators constitute an exceptional biological material for understanding mechanisms regulating plant metal homeostasis as well as plant adaptation to extreme metallic environments.Our understanding of metal hyperaccumulation physiology has recently increased as a result of the development of molecular tools. This review presents key aspects of our current understanding of plant metal – in particular cadmium (Cd),nickel (Ni) and zinc (Zn) – hyperaccumulation. PMID:19192189

Verbruggen, Nathalie; Hermans, Christian; Schat, Henk

2009-03-01

71

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

PubMed

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

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

2014-12-01

72

Using hyperaccumulator plants to phytoextract soil Ni and Cd.  

PubMed

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

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

73

Rhizosphere Characteristics of the Arsenic Hyperaccumulator Pteris  

E-print Network

Rhizosphere Characteristics of the Arsenic Hyperaccumulator Pteris vittata L. and Monitoring investigated changes in the rhizosphere characteristics of Pteris vittata (Chinese Brake fern) relevant for its

Ma, Lena

74

Compartmentation and complexation of metals in hyperaccumulator plants.  

PubMed

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

Leitenmaier, Barbara; Küpper, Hendrik

2013-01-01

75

Aerobic methane emissions from stinkweed (Thlaspi arvense) capsules.  

PubMed

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

Qaderi, Mirwais M; Reid, David M

2014-10-01

76

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

Microsoft Academic Search

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

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

2011-01-01

77

Selenium hyperaccumulation offers protection from cell disruptor herbivores  

Microsoft Academic Search

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

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

78

A test of elemental defence against slugs by Ni in hyperaccumulator and non-hyperaccumulator Streptanthus species  

Microsoft Academic Search

Summary. Tissues of most plant species contain ?1 but Ni hyperaccumulators contain more than 1000 ?g Ni g?1 . Hyperaccumulated Ni can defend plants from some herbivores but the defensive role of lesser Ni concentrations is little explored. We raised five species of Streptanthus (Brassicaceae) native to ultramafic soils, one of which (S. polygaloides) is a Ni hyperaccumulator whereas the others are

Robert S. Boyd; Edward M. Jhee

2005-01-01

79

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

E-print Network

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

Alvarez, Nadir

80

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

E-print Network

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

Ma, Lena

81

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

E-print Network

HYPERACCUMULATOR Pteris vittata L. By ANHUI HUANG A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY ...........................................................15 1.2. 3 Arsenic Hyperaccumulator Pteris Vittata L...............................................................22 1.4 Arsenic Hyperaccumulator Pteris vitttata L. as a Unique Model

Ma, Lena

82

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...

83

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...

84

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...

85

The ecological significance of nickel hyperaccumulation: a plant chemical defense  

Microsoft Academic Search

Nickel hyperaccumulating plants have more than 1000 mg Ni kg-1 dry weight when grown on nickel-bearing soils. We hypothesized that Ni hyperaccumulation could serve as a chemical defense against herbivores In feeding experiments with potential insect herbivores and Ni hyperaccumulating plants, only those inseets fed leaves from plants grown on non-nickel-bearing soil survived or showed a weight gain. Among chemical

Scott N. Martens; Robert S. Boyd

1994-01-01

86

The arsenic hyperaccumulator fern Pteris vittata L.  

PubMed

Arsenic (As) contaminated soils and waters are becoming major global environmental and human health risks. The identification of natural hyperaccumulators of As opens the door for phytoremediation of the arsenic contaminant. Pteris vittata is the first identified naturally evolving As hyperaccumulator. More than a decade after its discovery, we have made great progress in understanding the uptake, transport, and detoxification of As in the fern. The molecular mechanisms controlling As accumulation in P. vittata are now beginning to be recognized. In this review, we will try to summarize what we have learned about this As accumulator, with particular emphasis on the current knowledge of the physiological and molecular mechanisms of arsenic phytoremediation. We also discuss the potential strategies to further enhance phytoextraction abilities of P. vittata. PMID:20028042

Xie, Qing-En; Yan, Xiu-Lan; Liao, Xiao-Yong; Li, Xia

2009-11-15

87

Prospecting for hyperaccumulators of trace elements: a review.  

PubMed

Abstract Specific plant species that can take up and accumulate abnormally high concentrations of elements in their aboveground tissues are referred to as "hyperaccumulators". The use of this term is justified in the case of enormous element-binding capacity of plants growing in their natural habitats and showing no toxicity symptoms. An increasing interest in the study of hyperaccumulators results from their potential applications in environmental biotechnology (phytoremediation, phytomining) and their emerging role in nanotechnology. The highest number of plant species with confirmed hyperaccumulative properties has been reported for hyperaccumulators of nickel, cadmium, zinc, manganese, arsenic and selenium. More limited data exist for plants accumulating other elements, including common pollutants (chromium, lead and boron) or elements of commercial value, such as copper, gold and rare earth elements. Different approaches have been used for the study of hyperaccumulators - geobotanical, chemical, biochemical and genetic. The chemical approach is the most important in screening for new hyperaccumulators. This article presents and critically reviews current trends in new hyperaccumulator research, emphasizing analytical methodology that is applied in identification of new hyperaccumulators of trace elements and its future perspectives. PMID:24938121

Krzciuk, Karina; Ga?uszka, Agnieszka

2014-06-18

88

Arsenic speciation and distribution in an arsenic hyperaccumulating plant  

Microsoft Academic Search

Arsenic-contaminated soil is one of the major arsenic sources for drinking water. Phytoremediation, an emerging, plant-based technology for the removal of toxic contaminants from soil and water, has been receiving renewed attention. Although a number of plants have been identified as hyperaccumulators for the phytoextraction of a variety of metals, and some have been used in field applications, no hyperaccumulator

Weihua Zhang; Yong Cai; Cong Tu; Lena Q Ma

2002-01-01

89

Molecular mechanisms of heavy metal hyperaccumulation and phytoremediation  

Microsoft Academic Search

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

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

2005-01-01

90

Research papers Does hyperaccumulated nickel affect leaf decomposition?  

E-print Network

Research papers Does hyperaccumulated nickel affect leaf decomposition? A field test using Senecio and the other a non-hyper- accumulator population. Our main goal was to determine if leaf Ni status (hyperaccumulator or non-hyperaccu- mulator) affected leaf decomposition rate on serpentine sites. We also used

Boyd, Robert S.

91

The proteomics of heavy metal hyperaccumulation by plants.  

PubMed

Hyperaccumulators are distinguished from non-hyperaccumulators on the basis of their capacity to extract heavy metal ions from the soil, their more efficient root-to-shoot translocation of these ions and their greater ability to detoxify and sequester heavy metals in the shoot. The understanding of the mechanisms underlying metal ion accumulation has progressed beyond the relevant biochemistry and physiology to encompass the genetic and molecular regulatory systems which differentiate hyperaccumulators from non-hyperaccumulators. This paper reviews the literature surrounding the application of proteomics technology to plant metal hyperaccumulation, in particular involving the elements As, Cd, Cu, Ni, Pb and Zn. The hyperaccumulation process across a number of unrelated plant species appears to be associated with proteins involved in energy metabolism, the oxidative stress response and abiotic and biotic stress. The relevance of transducers of the metal stress response to the phenomenon of hyperaccumulation is summarized. Proteomic data complement the more voluminous genomic and transcriptomic data sets in providing a more nuanced picture of the process, and should therefore help in the identification of the major genetic determinants of the hyperaccumulation phenomenon. PMID:23268120

Visioli, Giovanna; Marmiroli, Nelson

2013-02-21

92

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...

93

Arsenic speciation, and arsenic and phosphate distribution in arsenic hyperaccumulator Pteris vittata L. and non-hyperaccumulator Pteris ensiformis L  

Microsoft Academic Search

This study 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 Brake fern), a non-arsenic hyperaccumulator. After growing in 20% Hoagland solution containing 0, 133 or 267?M of sodium arsenate for 1, 5 or 10d, the plants were separated into

Nandita Singh; Lena Q. Ma

2006-01-01

94

[Cu-hyperaccumulators in mining area].  

PubMed

Plant species distributing in three Cu-mining area were investigated, and Cu concentrations in soils and plants were analyzed. The results showed that Cu ore deposit mostly was distributed at the altitude of about 630 m. Elsholtzia splendens and Rumex acetosa were distributed only on the Cu ore deposit or the place with high Cu concentration, and the maximum Cu concentrations in these two plants were 1060 mg.kg-1 DW and 1006 mg.kg-1 DW, which reached the critical of hyperaccumulator. Cu accumulations in Elsholtzia splendens and Rumex acetosa were positively and closely correlated with Cu concentration in soil. PMID:12385229

Jiang, Liying; Shi, Weiyong; Yang, Xiaoe; Fu, Chengxin; Chen, Weiguang

2002-07-01

95

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

PubMed

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

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

2009-01-01

96

Cadmium tolerance and hyperaccumulation in a new Zn-hyperaccumulating plant species ( Sedum alfredii Hance)  

Microsoft Academic Search

Sedum alfredii Hance has been identified as a new zinc (Zn) hyperaccumulating plant species. In this study, the effects of cadmium (Cd) supply levels (control, 12.5, 25, 50, 100, 200, 400, 800 µmol Cd L-1) on the growth and cadmium accumulation and Zn supply on Cd accumulation in S. alfredii Hance were studied. The results showed that no reduction in shoot and root dry

X. E. Yang; X. X. Long; H. B. Ye; Z. L. He; D. V. Calvert; P. J. Stoffella

2004-01-01

97

Rhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns  

Microsoft Academic Search

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

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

2009-01-01

98

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

PubMed

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

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

2013-01-01

99

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

PubMed

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

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

2013-08-01

100

Molecular mechanisms of heavy metal hyperaccumulation and phytoremediation.  

PubMed

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 cellular/molecular mechanisms of metal tolerance/hyperaccumulation by plants are reviewed. The major processes involved in hyperaccumulation of trace metals from the soil to the shoots by hyperaccumulators include: (a) bioactivation of metals in the rhizosphere through root-microbe interaction; (b) enhanced uptake by metal transporters in the plasma membranes; (c) detoxification of metals by distributing to the apoplasts like binding to cell walls and chelation of metals in the cytoplasm with various ligands, such as phytochelatins, metallothioneins, metal-binding proteins; (d) sequestration of metals into the vacuole by tonoplast-located transporters. The growing application of molecular-genetic technologies led to the well understanding of mechanisms of heavy metal tolerance/accumulation in plants, and subsequently many transgenic plants with increased resistance and uptake of heavy metals were developed for the purpose of phytoremediation. Once the rate-limiting steps for uptake, translocation, and detoxification of metals in hyperaccumulating plants are identified, more informed construction of transgenic plants would result in improved applicability of the phytoremediation technology. PMID:16028496

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

2005-01-01

101

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...

102

Enhanced root-to-shoot translocation of cadmium in the hyperaccumulating ecotype of Sedum alfredii  

Microsoft Academic Search

Sedum alfredii (Crasulaceae) is the only known Cd- hyperaccumulating species that are not in the Bras- sica family; the mechanism of Cd hyperaccumulation in this plant is, however, little understood. Here, a combination of radioactive techniques, metabolic inhibitors, and fluorescence imaging was used to contrast Cd uptake and translocation between a hyper- accumulating ecotype (HE) and a non-hyperaccumulating ecotype (NHE)

Ling-li Lu; Sheng-ke Tian; Xiao-e Yang; Xiao-chang Wang; Patrick Brown; Ting-qiang Li; Zhen-li He

2008-01-01

103

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

PubMed

• 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

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

2011-07-01

104

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

E-print Network

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

105

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

Microsoft Academic Search

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.

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

2006-01-01

106

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

E-print Network

changes in AsÃ?hyperaccumulator Pteris vittata (PV). PV was grown for 60Ã?d in a soil spiked with 200 mg kg in soils and plants. Pteris vittata (PV), a wellÃ?known As hyperaccumulator, has a potential to be usedArsenic enhanced plant growth and altered rhizosphere characteristics of hyperaccumulator Pteris

Ma, Lena

107

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

Microsoft Academic Search

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

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

2008-01-01

108

Zinc Hyperaccumulation and Uptake by Potentilla Griffithii Hook  

Microsoft Academic Search

The ability of Potentilla griffithii Hook var. velutina Cardot to hypaeraccumulate zinc (Zn) was identified through field survey and hydroponic experiments. Our results showed that P. griffithii could be classified as a new Zn hyperaccumulator. Zn concentrations in the shoots of P. griffithii averaged 6250 mg kg (3870–8530 mg kg) growing in Zn-rich soils. The highest Zn concentration was observed

Rongliang Qiu; Xiaohang Fang; Yetao Tang; Suojun Du; Xiaowen Zeng; Eric Brewer

2006-01-01

109

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

110

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

111

Metal hyperaccumulation in plants - Biodiversity prospecting for phytoremediation technology  

Microsoft Academic Search

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

Majeti Narasimha Vara Prasad; Helena Maria De Oliveira Freitas

2003-01-01

112

Antimony uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata  

E-print Network

Article history: Received 12 September 2013 Received in revised form 26 November 2013 Accepted 29 November and translocated in plants. We investigated 1) Sb uptake, efflux and speciation in arsenic hyperaccumulator Pteris and efflux of SbIII with limited ability to translocate and transform in the roots. Ã? 2013 Elsevier Ltd. All

Ma, Lena

113

Selenium-Tolerant Diamondback Moth Disarms Hyperaccumulator Plant Defense  

Microsoft Academic Search

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

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

2006-01-01

114

Selenium hyperaccumulation offers protection from cell disruptor herbivores  

PubMed Central

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

2010-01-01

115

Does hyperaccumulated nickel affect leaf decomposition? A field test using Senecio coronatus (Asteraceae) in South Africa  

Microsoft Academic Search

Summary.  Nickel hyperaccumulator plants contain unusually elevated levels of Ni (>1,000 mg Ni kg?1). The high Ni concentration of hyperaccumulator tissues may affect ecosystem processes such as decomposition, but this has\\u000a yet to be studied under field conditions. We used Senecio coronatus Thunb. (Harv.) from two pairs of serpentine sites: one member of each pair contained a hyperaccumulator population and the\\u000a other

Robert S. Boyd; Micheal A. Davis; Kevin Balkwill

2008-01-01

116

Effect of cadmium toxicity on nitrogen metabolism in leaves of Solanum nigrum L. as a newly found cadmium hyperaccumulator  

Microsoft Academic Search

Hyperaccumulators are ideal plant species used for phytoremediation of soils contaminated by heavy metals. A full understanding of metal tolerance mechanisms of hyperaccumulators will facilitate enhancing their phytoremediation efficiency. However, how Cd affects N metabolism and which role plays the response of N metabolism to Cd toxicity in the tolerance of hyperaccumulators are still unknown. To clarify these questions, this

Lin Wang; Qixing Zhou; Lingling Ding; Yuebing Sun

2008-01-01

117

Arsenic hyperaccumulator Pteris Vittata L. and its arsenic accumulation  

Microsoft Academic Search

An arsenic hyperaccumulator Pteris vittata L. (Chinese brake) was first discovered in China by means of field survey and greenhouse cultivation. Field survey showed\\u000a that Chinese brake had large accumulating capacity to arsenic; the orders of arsenic content in different parts of the fern\\u000a were as follows: leaves>leafstalks>roots, which is totally different from that of ordinary plants; bioaccumulation coefficients\\u000a of

Tongbin Chen; Chaoyang Wei; Zechun Huang; Qifei Huang; Quanguo Lu; Zilian Fan

2002-01-01

118

Selenium-tolerant diamondback moth disarms hyperaccumulator plantdefense  

SciTech Connect

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.

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

2006-11-20

119

Accumulation and uptake of manganese in a hyperaccumulator Phytolacca americana  

Microsoft Academic Search

Phytolacca americana (pokeweed) has been found to be a new manganese hyperaccumulator plant by means of field surveys on Mn-rich soils and by Hydroponics experiments. This species not only has remarkable tolerance to Mn but also has extraordinary uptake and accumulation capacity for this element. The maximum Mn concentration in the leaf dry matter was 8000mg\\/g on Xiangtan Mn tailings

Yuan Min; Tie boqing; Tang Meizhen; Isao Aoyama

2007-01-01

120

Localization of the Site of Perception of Thermoinductive Temperatures in Thlaspi arvense L.  

PubMed

This paper describes attempts to localize the site of perception of low temperatures (0-10 degrees C) during thermoinduction in Thlaspi arvense L. Reproductive development (stem elongation and flower formation) was observed when shoots were cooled to 4 degrees C for 4 weeks and then returned to 21 degrees C while maintaining the roots constant 21 degrees C. However, chilling the roots was ineffective for initiating reproductive development. The apparent site of perception of thermoinductive temperatures was further localized to the shoot tip (apex and immature leaves) by controlling the temperature of the shoot tip independently of the rest of the plant. Furthermore, excised apices regenerated flowering plants in organ culture only if they were subjected to a 4 week cold treatment. Grafting experiments also support the notion that the shoot tip or the apex is the site of perception of thermoinductive temperatures: noninduced shoot tips grafted onto bolting donors remained as vegetative rosettes. Paradoxically, it was found that the cells of the shoot tip are not the only ones capable of being thermoinduced. Shoots regenerated from leaf cuttings excised from thermoinduced plants exhibited all signs of reproductive development, while regenerated shoots from control leaves developed into vegetative rosettes. It is suggested that many cell types are capable of being thermoinduced and that the shoot tip may appear to be the site of perception of thermoinductive temperatures because structures associated with reproductive development originate from this tissue. PMID:16666320

Metzger, J D

1988-10-01

121

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

PubMed Central

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

Metzger, James D.; Mardaus, Marcia C.

1986-01-01

122

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

E-print Network

Absorption 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 by the brake fern; also examined were the effects of foliar sprays on surface ultrastructure and arsenic

Ma, Lena

123

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

124

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

E-print Network

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

Sparks, Donald L.

125

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

Microsoft Academic Search

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

Jo Ann Banks; David Salt

2008-01-01

126

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

127

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

E-print Network

vittata L. and non-hyperaccumulator Pteris ensiformis L. Nandita Singh 1 , Lena Q. Ma* Soil and Water; accepted 19 August 2005 Pteris vittata may effectively reduce arsenite in its fronds. Abstract This study of Pteris vittata L. (Chinese Brake fern), an arsenic hyperaccumulator and Pteris ensiformis L. (Slender

Ma, Lena

128

Bacteria-Mediated Arsenic Oxidation and Reduction in the Growth Media of Arsenic Hyperaccumulator Pteris vittata  

E-print Network

Pteris vittata Xin Wang,,,§ Bala Rathinasabapathi,§ Letuzia Maria de Oliveira,, Luiz R. G. Guilherme in the growth media of arsenic hyperaccumulator Pteris vittata L. All arsenite (AsIII) at 0.1 mM in the media. Arsenic hyperaccumulator Pteris vittata L has a potential to bioremediate arsenic-contaminated soils

Ma, Lena

129

An Arsenate-activated Glutaredoxin from the Arsenic Hyperaccumulator Fern Pteris vittata L. Regulates  

E-print Network

An Arsenate-activated Glutaredoxin from the Arsenic Hyperaccumulator Fern Pteris vittata L To elucidate the mechanisms of arsenic resistance in the arsenic hyperaccumulator fern Pteris vittata L., a c) reported that Chinese brake fern Pteris vittata was resistant to arsenic and was capable

Ma, Lena

130

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

E-print Network

the chemical characteristics of the rhizosphere of two arsenic hyperaccumulators Pteris vittata and PterisRhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns Maria Isidória Silva-P), pH, and dissolved organic carbon (DOC). Comparing the two plants, P. vittata was more tolerant

Ma, Lena

131

Determination of the Cellular Mechanisms Regulating Thermo-Induced Stem Growth in Thlaspi arvense L.  

PubMed

Field pennycress (Thlaspi arvense L.) is a species with a cold requirement for the initiation of reproductive development (thermoinduction). Work in this laboratory has been focused on elucidating the biochemical and molecular mechanisms underlying the bolting or rapid stem elongation response that is an intricate part of reproductive development in this species. In the present paper the cellular basis for thermo-induced stem growth was determined. Evidence is presented indicating that bolting results from the production of new cells that elongate to their original length before thermoinduction. This increase in cell division occurs in the pith and cortex approximately 0.5 to 5.0 millimeters below the stem apex. For at least the early stages of thermo-induced stem growth, enhanced cell elongation does not appear to be a factor because average lengths of pith cells from stems of thermo-induced plants were similar or less than noninduced controls. In addition, both the amount of increase in the production of new pith cells and stem growth were positively correlated with the length of the cold treatment. Two other lines of evidence are presented corroborating previous assertions (JD Metzger [1985] Plant Physiol 78: 8-13) that gibberellins mediate thermo-induced stem growth in field pennycress. First, treatment of noninduced plants with gibberellin A(3) completely mimicked the effects of a 4-week cold treatment on mitotic activity in the pith and cortex. Second, very little increase in the production of new cells was observed in the pith and cortex of thermo-induced plants of a gibberellin-deficient dwarf mutant of field pennycress. It is also shown that the influence of photoperiod on stem growth is mediated by an effect on the final length that cells ultimately attain. PMID:16668445

Metzger, J D; Dusbabek, K

1991-10-01

132

Role of Gibberellins in the Environmental Control of Stem Growth in Thlaspi arvense L  

PubMed Central

Field pennycress (Thlaspi arvense L.) is a winter annual that requires a cold treatment for the induction of stem elongation. An inbred line was selected in which no stem elongation was observed in plants grown for 6 months at 21°C regardless of the prevailing photoperiod. Increased exposure time of plants grown initially at 21°C to cold (2°C) induced a greater rate of stem elongation when the plants were returned to 21°C. Moreover, longer cold treatments resulted in a greater maximum stem height and reduced the lag period for the onset of measurable internode elongation. The optimal temperature range for thermoinduced stem growth was broad: rates of stem growth in plants maintained for 4 weeks at either 2° or 10°C were virtually identical. However, a 4-week thermoinductive treatment at 15°C resulted in a greater lag period for the initiation of stem elongation and a decreased growth rate. The rate of cold-induced stem elongation was greater in plants subjected to long days than for plants subjected to short days following the cold treatment. Thus, photoperiod does not control the induction of stem elongation, but does regulate stem elongation in progress. Exogenous gibberellin A3 (GA3) was able to substitute for the cold requirement, but elicited a greater response in plants maintained under long days than short days. This indicates that photoperiod influences the plant's sensitivity to GAs. The GA biosynthesis inhibitor, 2-chloroethyltrimethyl ammonium chloride, inhibited low temperature-induced stem elongation, and this inhibition was completely reversed by exogenous GA3. These results suggest that cold-induced stem elongation in field pennycress is mediated by some change in the endogenous GA status. PMID:16664213

Metzger, James D.

1985-01-01

133

Molecular mechanisms of selenium tolerance and hyperaccumulation in Stanleya pinnata.  

PubMed

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

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

134

Zinc hyperaccumulation and uptake by Potentilla griffithii Hook.  

PubMed

The ability of Potentilla griffithii Hook var. velutina Cardot to hypaeraccumulate zinc (Zn) was identified through field survey and hydroponic experiments. Our results showed that P. griffithii could be classified as a new Zn hyperaccumulator. Zn concentrations in the shoots of P. griffithii averaged 6250 mg kg(-1) (3870-8530 mg kg(-1)) growing in Zn-rich soils. The highest Zn concentration was observed in the leaves of P. griffithii at 22,990 mg kg(-1). The fact that P. griffithii was able to grow in a mining soil with a Zn concentration of 193,000 mg kg(-1) without showing a major sign of phytotoxicity demonstrated its high tolerance to Zn. When growing in hydroponic systems, P. griffithii accumulated a maximum 26700 mg kg(-1) zinc concentration in the shoots, indicating the ability of this species to effectively take up and translocate Zn. Translocation factors (the ratio of Zn concentration in shoot to root) of 1.1 to 1.6 were obtained. Compared to the control, dry biomass of P. griffithii in 160 mg L(-1) Zn treatment increased 66.6% (P < 0.05). The time-course experiment showed that the maximum Zn concentration at 100 mg L(-1) Zn treatment was found at 16 d, much later than that of the 10 mg L(-1) Zn treatment, which might be an attribution of a accumulating mechanism or detoxification of a plant. The report of a new Zn hyperaccumulator provides a new plant species for the phytoremediation of contaminated soil and for the research on mechanisms of Zn hyperaccumulation in plants. PMID:17305304

Qiu, Rongliang; Fang, Xiaohang; Tang, Yetao; Du, Suojun; Zeng, Xiaowen; Brewer, Eric

2006-01-01

135

Rhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns.  

PubMed

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

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

2009-08-01

136

Tissue Fractions of Cadmium in Two Hyperaccumulating Jerusalem Artichoke Genotypes  

PubMed Central

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

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

2014-01-01

137

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

PubMed

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

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

2013-02-01

138

Youngia erythrocarpa, a newly discovered cadmium hyperaccumulator plant.  

PubMed

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

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

2015-01-01

139

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

PubMed Central

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

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

2013-01-01

140

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

E-print Network

is necessary for protecting both human life and agricultural produc- tion. Phytoremediation of As of phytoremediation is determined by two factors, i.e., identification of plants with high As hyperaccumulating poten

Ma, Lena

141

ARSENIC UPTAKE BY TWO HYPERACCUMULATOR FERNS FROM FOUR ARSENIC CONTAMINATED SOILS  

E-print Network

. 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

Ma, Lena

142

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

E-print Network

four nuclear gene regions and performed a phylogenetic analysis. Ancestral recon- struction was used mapping the occurrence of hyperaccumulators on the angiosperm phy- logeny (Cappa & Pilon-Smits, 2014

143

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

SciTech Connect

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.

David E. Salt

2002-04-08

144

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

PubMed

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

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

2014-02-01

145

Arsenic complexes in the arsenic hyperaccumulator Pteris vittata (Chinese brake fern)  

Microsoft Academic Search

Pteris vittata (Chinese brake fern), the first reported arsenic (As) hyperaccumulating plant, can be potentially applied in the phytoremediation of As-contaminated sites. Understanding the mechanisms of As tolerance and detoxification in this plant is critical to further enhance its capability of As hyperaccumulation. In this study, an unknown As species, other than arsenite (AsIII) or arsenate (AsV) was found in

Weihua Zhang; Yong Cai; Kelsey R Downum; Lena Q Ma

2004-01-01

146

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

PubMed

Using the gamma-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 castellana Boiss. et Reuter. Based on plant-internal PC-thiol to metal molar ratios, the metals' tendency to induce PC accumulation decreased in the order As/Cd/Cu > Zn > Ni/Co, and was consistently higher in non-metallicolous plants than in hypertolerant ones, except for the case of As. The sensitivities to Cu, Zn, Ni, and Co were consistently unaffected by BSO treatment, both in non-metallicolous and hypertolerant plants, suggesting that PC-based sequestration is not essential for constitutive tolerance or hypertolerance to these metals. Cd sensitivity was considerably increased by BSO, though exclusively in plants lacking Cd hypertolerance, suggesting that adaptive cadmium hypertolerance is not dependent on PC-mediated sequestration. BSO dramatically increased As sensitivity, both in non-adapted and As-hypertolerant plants, showing that PC-based sequestration is essential for both normal constitutive tolerance and adaptive hypertolerance to this metalloid. The primary function of PC synthase in plants and algae remains elusive. PMID:12432030

Schat, Henk; Llugany, Mercè; Vooijs, Riet; Hartley-Whitaker, Jeanette; Bleeker, Petra M

2002-12-01

147

This paper reviews progress in phytoextraction of soil elements and illustrates the key role of hyperaccumulator plant species  

E-print Network

process that allows these plants to achieve hyperaccumulation. Cadmium phytoextraction is needed for rice the elements from the field. Phytoextraction is a subset of phytoremediation which includes phytostabilization

Sparks, Donald L.

148

Mechanisms of efficient arsenite uptake by arsenic hyperaccumulator Pteris vittata.  

PubMed

Arsenate (AsV) and arsenite (AsIII) are two dominant arsenic species in the environment. While arsenate uptake is via phosphate transporter in plants, including arsenic hyperaccumulator Pteris vittata , AsIII uptake mechanisms by P. vittata are unclear. In this study, we investigated AsIII uptake by P. vittata involving root radial transport from external medium to cortical cells and xylem loading. In the root symplastic solution, AsIII was the predominant species (90-94%) and its concentrations were 1.6-21 times those in the medium. AsIII influx into root symplast followed Michaelis-Menten kinetics with K(m) of 77.7 ?M at external AsIII concentrations of 2.6-650 ?M. In the presence of metabolic inhibitor 2,4-dinitrophenol (DNP), arsenic concentrations in the root symplast were reduced to the levels lower than in the medium, indicating that a transporter-mediated active process was mainly responsible for AsIII influx into P. vittata roots. Unlike radial transport, AsIII loading into xylem involved both high- and low-affinity systems with K(m) of 8.8 ?M and 70.4 ?M, respectively. As indicated by the effect of 2,4-DNP, passive diffusion became more important in arsenic loading into xylem at higher external AsIII. The unique AsIII uptake system in P. vittata makes it a valuable model to understand the mechanisms of arsenic hyperaccumulation in the plant kingdom. PMID:22029254

Wang, Xin; Ma, Lena Q; Rathinasabapathi, Bala; Cai, Yong; Liu, Yun Guo; Zeng, Guang Ming

2011-11-15

149

Analysis of selenium accumulation, speciation and tolerance of potential selenium hyperaccumulator Symphyotrichum ericoides.  

PubMed

Symphyotrichum ericoides was shown earlier to contain hyperaccumulator levels of selenium (Se) in the field (>1000 mg kg(-1) dry weight (DW)), but only when growing next to other Se hyperaccumulators. It was also twofold larger next to hyperaccumulators and suffered less herbivory. This raised two questions: whether S. ericoides is capable of hyperaccumulation without neighbor assistance, and whether its Se-derived benefit is merely ecological or also physiological. Here, in a comparative greenhouse study, Se accumulation and tolerance of S. ericoides were analyzed in parallel with hyperaccumulator Astragalus bisulcatus, Se accumulator Brassica juncea and related Asteraceae Machaeranthera tanacetifolia. Symphyotrichum ericoides and M. tanacetifolia accumulated Se up to 3000 and 1500 mg Se kg(-1) DW, respectively. They were completely tolerant to these Se levels and even grew 1.5- to 2.5-fold larger with Se. Symphyotrichum ericoides showed very high leaf Se/sulfur (S) and shoot/root Se concentration ratios, similar to A. bisulcatus and higher than M. tanacetifolia and B. juncea. Se X-ray absorption near-edge structure spectroscopy showed that S. ericoides accumulated Se predominantly (86%) as C-Se-C compounds indistinguishable from methyl-selenocysteine, which may explain its Se tolerance. Machaeranthera tanacetifolia accumulated 55% of its Se as C-Se-C compounds; the remainder was inorganic Se. Thus, in this greenhouse study S. ericoides displayed all of the characteristics of a hyperaccumulator. The larger size of S. ericoides when growing next to hyperaccumulators may be explained by a physiological benefit, in addition to the ecological benefit demonstrated earlier. PMID:24423113

El Mehdawi, Ali F; Reynolds, Ray Jason B; Prins, Christine N; Lindblom, Stormy D; Cappa, Jennifer J; Fakra, Sirine C; Pilon-Smits, Elizabeth A H

2014-09-01

150

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

E-print Network

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

Ma, Lena

151

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

PubMed

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

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

152

Complexation with dissolved organic matter and mobility control of heavy metals in the rhizosphere of hyperaccumulator Sedum alfredii  

E-print Network

Keywords: Cadmium Complexation Dissolved organic matter Hyperaccumulator Lead Zinc a b s t r a c. To optimize the potential use of hyperaccumulators for phytoremediation, basic information on the rhizosphere exaltata. Recent studies showed that concentrations of NH4NO3-extractable Zn and cadmium (Cd

Sparks, Donald L.

153

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

E-print Network

% of dry weight. This study was performed to obtain insight into whole-plant Se fluxes in hyperaccumulators 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. Key words

154

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

Microsoft Academic Search

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

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

2004-01-01

155

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

156

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

E-print Network

Low molecular weight thiols in arsenic hyperaccumulator Pteris vittata upon exposure to arsenic in the arsenic hyperaccumulator Pteris vittata. Abstract Low molecular weight thiol-containing compounds have, Chinese Brake fern (Pteris vittata) upon exposure to arsenic and other trace metals was investigated

Ma, Lena

157

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

PubMed

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

Dalcorso, Giovanni; Fasani, Elisa; Furini, Antonella

2013-01-01

158

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

PubMed Central

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

DalCorso, Giovanni; Fasani, Elisa; Furini, Antonella

2013-01-01

159

First evidence on different transportation modes of arsenic and phosphorus in arsenic hyperaccumulator Pteris vittata.  

PubMed

Arsenic (As) reduction and translocation are key processes for As hyperaccumulation by the hyperaccumulator Pteris vittata L. Micro-X-ray adsorption spectroscopy of P. vittata's rhizoid tissues revealed that As reduction mainly occurred in endodermis during translocation from epidermis to vascular bundle. Prior to reduction, arsenate (As (V)) translocation was an active process requiring energy and employing a phosphate (P) transporter. Use of a synchrotron X-ray microprobe showed that As (V) and P were cotransported and that this process could be enhanced by As (V) exposure or P deficiency but restrained by energy release inhibition caused by 2,4-dinitrophenol or sodium orthovanadate. In contrast, after As reduction, As(III) translocation differed from P translocation and was more efficient, appearing free from the apparent endodermal blockage. The results here revealed the role of the P transporter on As translocation as well as the key role of As reduction in As hyperaccumulation by P. vittata. PMID:22230060

Lei, Mei; Wan, Xiao-Ming; Huang, Ze-Chun; Chen, Tong-Bin; Li, Xue-Wen; Liu, Ying-Ru

2012-02-01

160

Accumulation and detoxification of manganese in hyperaccumulator Phytolacca americana.  

PubMed

Pokeweed (Phytolacca americana) has recently received much attention because of its ability to hyperaccumulate manganese (Mn). The internal mechanism of detoxification of Mn, however, is not fully understood. In the present study, we investigated Mn accumulation, subcellular distribution, chemical speciation and detoxification through oxalate in pokeweed. The plant accumulated excess Mn in the leaves, mainly in the water-soluble fraction, and over 80% of Mn was in a water-soluble form, while accumulation of excess Mn in the cellular organelle and membrane fraction caused phytotoxicity. In addition, pokeweed has an intrinsically high oxalate content. In all experiments, there was sufficient oxalate to chelate Mn in leaf water extracts at all different levels of Mn application. Phase analysis of X-ray diffraction detected oxalate-Mn chelate complexes, and gel chromatography further confirmed the chelation of Mn by oxalate. In conclusion, pokeweed accumulates excess Mn in the soluble fraction of leaf cells, most likely in vacuoles, in which detoxification of Mn could be achieved by chelation with oxalate. PMID:19689773

Dou, C-M; Fu, X-P; Chen, X-C; Shi, J-Y; Chen, Y-X

2009-09-01

161

Successful Seed Germination of the Nickel Hyperaccumulator Stackhousia tryonii  

PubMed Central

• Background and Aims Stackhousia tryonii, a rare nickel hyperaccumulating herb, is endemic to ultramafic (serpentine) soils of central Queensland, Australia. The effects of eight dormancy-relieving treatments on germination of stored seeds of Stackhousia tryonii were investigated under controlled light and temperature conditions. • Methods The treatments were: untreated (control i), leached and dehydrated (primed control ii), treating with gibberellic acid (150 and 300 µM), smoke extract (5 and 10 %, v/v) and potassium cyanide (40 and 80?mM). • Key Results Freshly harvested seeds did not germinate. Germination percentage increased with time of storage for up to 18 months (38·3 %). Gibberellin, smoke extract and cyanide treatments did not significantly improve germination. Light did not affect seed germination and there was no interaction between dormancy-relieving treatments and light. A significant inhibition of germination occurred in seeds treated with 5 % (but not 10 %) aqueous smoke extract. Saturated fatty acids, predominantly tridecanoic (C13:0), constituted about 90 % of the total fatty acids in the oil of freshly harvested seeds. In contrast, there was increased accumulation (>75 %) of mono-unsaturated (oleic, C18:1) and poly-unsaturated (linoleic, C18:2; linolenic, C18:3) fatty acids in the oil of stored seeds. • Conclusions Seeds of S. tryonii require an after-ripening period for germination. PMID:15840638

BHATIA, NAVEEN P.; NKANG, ANI E.; WALSH, KERRY B.; BAKER, ALAN J. M.; ASHWATH, NANJAPPA; MIDMORE, DAVID J.

2005-01-01

162

The effect of nitrogen form on rhizosphere soil pH and zinc phytoextraction by Thlaspi caerulescens.  

PubMed

The phytoextraction of Zn may be improved by applying N fertilizers to increase the biomass and Zn content of shoots. Rhizosphere-pH change from uptake of different N forms will affect Zn phyto-availability in the rhizosphere and Zn phytoextraction. This glasshouse study examined the effect of N form on Zn phytoextraction by Thlaspi caerulescens (Prayon). The plants were grown in a Zn-contaminated soil (total Zn 250 mg kg-1 soil; pHwater 5.7) and supplied with (NH4)2SO4, Ca(NO3)2 or urea [(NH2)2CO]. The form was maintained by applying the nitrification inhibitor dicyandiamide. A biodegradable chelator ethylenediaminedisuccinic acid (EDDS) was included for comparison. The addition of N doubled the shoot biomass. The highest shoot Zn content occurred in the Ca(NO3)2 treatment and was associated with the highest rhizosphere pH. The lowest shoot dry weight occurred in the EDDS treatment. The Zn concentration in the shoots increased as the rhizosphere pH increased. A significant correlation occurred between Ca and Zn concentrations in the shoots. This study demonstrated that Ca(NO3)2 is a more effective treatment than , urea or EDDS for enhancing Zn phytoextraction in a mildly acidic soil. PMID:18752830

Monsant, A C; Tang, C; Baker, A J M

2008-10-01

163

Herbicide Chlorsulfuron Decreases Assimilate Transport Out of Treated Leaves of Field Pennycress (Thlaspi arvense L.) Seedlings 1  

PubMed Central

Treatment of field pennycress (Thlaspi arvense L.) leaves with the herbicide chlorsulfuron resulted in a decrease in the export of assimilate. Twelve hours after a spot application of 1 microgram, assimilate translocation was 70% of that in control leaves. In excised leaves treated with chlorsulfuron the total amounts of sugars and free amino acids were 150 and 170%, respectively, of the amounts in control leaves, 30 hours after herbicide treatment. The amount of sucrose was 247% of that in control leaves. The increase in the concentration of sucrose in the chlorsulfuron-treated leaves, combined with the absence of an effect of chlorsulfuron on carbon dioxide fixation, suggests that the decrease in assimilate transport is not due to an effect on the synthesis of assimilates, but rather to an effect on their movement out of the leaves. Supplying branched-chain amino acids to the field pennycress seedlings prior to the application of chlorsulfuron prevented the occurrence of the effects described. Images Figure 4 Figure 5 PMID:16667637

Bestman, Hank D.; Devine, Malcolm D.; Born, William H. Vanden

1990-01-01

164

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

PubMed

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

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

2009-06-01

165

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

PubMed

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

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

2008-03-01

166

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

PubMed

Even though antimony (Sb) and arsenic (As) are chemical analogs, differences exist on how they are taken up and translocated in plants. We investigated 1) Sb uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata after 1 d exposure to 1.6 or 8 mg/L antimonite (SbIII) or antimonate (SbV), 2) Sb uptake by PV accessions from Florida, China, and Brazil after 7 d exposure to 8 mg/L SbIII, and 3) Sb uptake and oxidation by excised PV fronds after 1 d exposure to 8 mg/L SbIII or SbV. After 1 d exposure, P. vittata took 23-32 times more SbIII than SbV, with all Sb being accumulated in the roots with the highest at 4,192 mg/kg. When exposed to 8 mg/L SbV, 98% of Sb existed as SbV in the roots. In comparison, when exposed to 8 mg/L SbIII, 81% of the total Sb remained as SbIII and 26% of the total Sb was effluxed out into the media. The three PV accessions had a similar ability to accumulate Sb at 12,000 mg/kg in the roots, with >99% of total Sb in the roots. Excised PV fronds translocated SbV more efficiently from the petioles to pinnae than SbIII and were unable to oxidize SbIII. Overall, P. vittata displayed efficient root uptake and efflux of SbIII with limited ability to translocate and transform in the roots. PMID:24370668

Tisarum, Rujira; Lessl, Jason T; Dong, Xiaoling; de Oliveira, Letuzia M; Rathinasabapathi, Bala; Ma, Lena Q

2014-03-01

167

Forms of Zinc Accumulated in the Hyperaccumulator Arabidopsis halleri1  

PubMed Central

The chemical forms of zinc (Zn) in the Zn-tolerant and hyperaccumulator Arabidopsis halleri and in the non-tolerant and nonaccumulator Arabidopsis lyrata subsp. petraea were determined at the molecular level by combining chemical analyses, extended x-ray absorption spectroscopy (EXAFS), synchrotron-based x-ray microfluorescence, and ?EXAFS. Plants were grown in hydroponics with various Zn concentrations, and A. halleri specimens growing naturally in a contaminated site were also collected. Zn speciation in A. halleri was independent of the origin of the plants (contaminated or non-contaminated) and Zn exposure. In aerial parts, Zn was predominantly octahedrally coordinated and complexed to malate. A secondary organic species was identified in the bases of the trichomes, which contained elevated Zn concentrations, and in which Zn was tetrahedrally coordinated and complexed to carboxyl and/or hydroxyl functional groups. This species was detected thanks to the good resolution and sensitivity of synchrotron-based x-ray microfluorescence and ?EXAFS. In the roots of A. halleri grown in hydroponics, Zn phosphate was the only species detected, and is believed to result from chemical precipitation on the root surface. In the roots of A. halleri grown on the contaminated soil, Zn was distributed in Zn malate, Zn citrate, and Zn phosphate. Zn phosphate was present in both the roots and aerial part of A. lyrata subsp. petraea. This study illustrates the complementarity of bulk and spatially resolved techniques, allowing the identification of: (a) the predominant chemical forms of the metal, and (b) the minor forms present in particular cells, both types of information being essential for a better understanding of the bioaccumulation processes. PMID:12481065

Sarret, Géraldine; Saumitou-Laprade, Pierre; Bert, Valérie; Proux, Olivier; Hazemann, Jean-Louis; Traverse, Agnès; Marcus, Matthew A.; Manceau, Alain

2002-01-01

168

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

E-print Network

L. Sparks, Ph.D. Chair of the Department of Plant and Soil Sciences ApprovedTHE PLANT SOIL INTERFACE: NICKEL BIOAVAILABILITY AND THE MECHANISMS OF PLANT HYPERACCUMULATION fulfillment of the requirements for the degree of Doctor of Philosophy in Plant and Soil Sciences Winter 2006

Sparks, Donald L.

169

The metal hyperaccumulators from New Caledonia can broaden our understanding of nickel accumulation in plants.  

PubMed

While an excess of metals such as zinc, cadmium or nickel (Ni) is toxic for most plants, about 500 plant species called hyperaccumulators are able to accumulate high amounts of these metals. These plants and the underlying mechanisms are receiving an increasing interest because of their potential use in sustainable biotechnologies such as biofortification, phytoremediation, and phytomining. Among hyperaccumulators, about 400 species scattered in 40 families accumulate Ni. Despite this wide diversity, our current knowledge of the mechanisms involved in Ni accumulation is still limited and mostly restricted to temperate herbaceous Brassicaceae. New Caledonia is an archipelago of the tropical southwest pacific with a third of its surface (5500 km(2)) covered by Ni-rich soils originating from ultramafic rocks. The rich New Caledonia flora contains 2145 species adapted to these soils, among which 65 are Ni hyperaccumulators, including lianas, shrubs or trees, mostly belonging to the orders Celastrales, Oxalidales, Malpighiales, and Gentianales. We present here our current knowledge on Ni hyperaccumulators from New Caledonia and the latest molecular studies developed to better understand the mechanisms of Ni accumulation in these plants. PMID:23898341

Jaffré, Tanguy; Pillon, Yohan; Thomine, Sébastien; Merlot, Sylvain

2013-01-01

170

Nickel hyperaccumulation as an elemental defense of Streptanthus polygaloides (Brassicaceae): influence of herbivore feeding mode.  

PubMed

No study of a single nickel (Ni) hyperaccumulator species has investigated the impact of hyperaccumulation on herbivores representing a variety of feeding modes. Streptanthus polygaloides plants were grown on high- or low-Ni soils and a series of no-choice and choice feeding experiments was conducted using eight arthropod herbivores. Herbivores used were two leaf-chewing folivores (the grasshopper Melanoplus femurrubrum and the lepidopteran Evergestis rimosalis), a dipteran rhizovore (the cabbage maggot Delia radicum), a xylem-feeder (the spittlebug Philaenus spumarius), two phloem-feeders (the aphid, Lipaphis erysimi and the spidermite Trialeurodes vaporariorum) and two cell-disruptors (the bug Lygus lineolaris and the whitefly Tetranychus urticae). Hyperaccumulated Ni significantly decreased survival of the leaf-chewers and rhizovore, and significantly reduced population growth of the whitefly cell-disruptor. However, vascular tissue-feeding insects were unaffected by hyperaccumulated Ni, as was the bug cell-disruptor. We conclude that Ni can defend against tissue-chewing herbivores but is ineffective against vascular tissue-feeding herbivores. The effects of Ni on cell-disruptors varies, as a result of either variation of insect Ni sensitivity or the location of Ni in S. polygaloides cells and tissues. PMID:16219073

Jhee, Edward M; Boyd, Robert S; Eubanks, Micky D

2005-11-01

171

Effects of arsenate and phosphate on their accumulation by an arsenic-hyperaccumulator Pteris vittata L  

Microsoft Academic Search

Arsenate and phosphate interactions are important for better understanding their uptake and accumulation by plant due to their similarities in chemical behaviors. The present study examined the effects of arsenate and phosphate on plant biomass and uptake of arsenate and phosphate by Chinese brake (Pteris vittata L.), a newly-discovered arsenic hyperaccumulator. The plants were grown for 20 weeks in a

Cong Tu; Lena Q. Ma

2003-01-01

172

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

Microsoft Academic Search

The fact that heavy metals can enter various domains of the plant system through foliar pathways spurred us to explore if the fronds of the Chinese brake fern (Pteris vittata L.), a hyperaccumulator of arsenic, a carcinogenic metalloid, was proficient in absorbing arsenic in the form of sprays. The specific objective of this study was to investigate the impact of

Bhaskar R. Bondada; Shuxin Tu; Lena Q. Ma

2004-01-01

173

Arsenic Uptake by Two Hyperaccumulator Ferns from Four Arsenic Contaminated Soils  

Microsoft Academic Search

A greenhouse study was conducted to evaluate and compare arsenic accumulation from four arsenic contaminated soils by two arsenic hyperaccumulators, Pteris vittata and Pteris cretica. After growing in soils for six weeks, the plants were harvested and separated into above- and below-ground biomass. Total As, P, Ca, K, glutathione and biomass were measured for the plants, and total As, Mehlich-3

A. O. Fayiga; L. Q. Ma

2005-01-01

174

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...

175

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

Microsoft Academic Search

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

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

1997-01-01

176

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

E-print Network

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

Ma, Lena

177

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...

178

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

Microsoft Academic Search

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

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

1997-01-01

179

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

PubMed Central

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

Yang, Xiaoe; Liu, Jian-Xiang

2013-01-01

180

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

E-print Network

Arsenic transformation in the growth media and biomass of hyperaccumulator Pteris vittata L. Shiny history: Received 8 December 2009 Received in revised form 11 February 2010 Accepted 15 May 2010 Available t This study determined the role of plant and microbes in arsenite (AsIII) oxidation in the growth media

Ma, Lena

181

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

PubMed

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

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

2014-02-01

182

Uncoupling of reactive oxygen species accumulation and defence signalling in the metal hyperaccumulator plant Noccaea caerulescens.  

PubMed

The metal hyperaccumulator plant Noccaea caerulescens is protected from disease by the accumulation of high concentrations of metals in its aerial tissues, which are toxic to many pathogens. As these metals can lead to the production of damaging reactive oxygen species (ROS), metal hyperaccumulator plants have developed highly effective ROS tolerance mechanisms, which might quench ROS-based signals. We therefore investigated whether metal accumulation alters defence signalling via ROS in this plant. We studied the effect of zinc (Zn) accumulation by N. caerulescens on pathogen-induced ROS production, salicylic acid accumulation and downstream defence responses, such as callose deposition and pathogenesis-related (PR) gene expression, to the bacterial pathogen Pseudomonas syringae pv. maculicola. The accumulation of Zn caused increased superoxide production in N. caerulescens, but inoculation with P. syringae did not elicit the defensive oxidative burst typical of most plants. Defences dependent on signalling through ROS (callose and PR gene expression) were also modified or absent in N. caerulescens, whereas salicylic acid production in response to infection was retained. These observations suggest that metal hyperaccumulation is incompatible with defence signalling through ROS and that, as metal hyperaccumulation became effective as a form of elemental defence, normal defence responses became progressively uncoupled from ROS signalling in N. caerulescens. PMID:23758201

Fones, Helen N; Eyles, Chris J; Bennett, Mark H; Smith, J Andrew C; Preston, Gail M

2013-09-01

183

Transcriptomic analysis of cadmium stress response in the heavy metal hyperaccumulator Sedum alfredii Hance.  

PubMed

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 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

Gao, Jun; Sun, Ling; Yang, Xiaoe; Liu, Jian-Xiang

2014-01-01

184

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

185

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

186

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

E-print Network

Abstract Arsenic hyperaccumulator Pteris vittata L. (Chinese brake fern) grows well in arsenic Glycolysis Ã? Pteris vittata Ã? Triosephosphate isomerase Abbreviations cTPI Cytosolic triosephosphate strategy was employed to identify cDNAs for the genes involved in arsenic resistance in P. vittata. Excised

Ma, Lena

187

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

E-print Network

was to understand the speciation and leachability of arsenic in the fronds of Chinese brake (Pteris vittata LArsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.) Cong Tu1a , Lena Q. Maa, *, Weihua Zhangb , Yong Caib , Willie G. Harrisa a Soil and Water

Ma, Lena

188

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

E-print Network

Phytoextraction by arsenic hyperaccumulator Pteris vittata L. from six arsenic-contaminated soils Received 23 May 2007; received in revised form 26 September 2007; accepted 7 October 2007 Pteris vittata This greenhouse experiment evaluated arsenic removal by Pteris vittata and its effects on arsenic redistribution

Ma, Lena

189

Characterization of arsenic-resistant bacteria from the rhizosphere of arsenic hyperaccumulator  

E-print Network

Pteris vittata Anhui Huang, Max Teplitski, Bala Rathinasabapathi, and Lena Ma Abstract: Arsenic hyperaccumulator fern Pteris vittata L. produces large amounts of root exudates that are hypothesized to solubilize vittata, osmotic stress, oxidative stress, arsenate reduction. Re´sume´ : La fouge`re Pteris vittata L

Ma, Lena

190

Cd-induced changes in leaf proteome of the hyperaccumulator plant Phytolacca americana  

Microsoft Academic Search

Cadmium (Cd) is highly toxic to all organisms. Soil contamination by Cd has become an increasing problem worldwide due to the intensive use of Cd-containing phosphate fertilizers and industrial zinc mining. Phytolacca americana L. is a Cd hyperaccumulator plant that can grow in Cd-polluted areas. However, the molecular basis for its remarkable Cd resistance is not known. In this study,

Le Zhao; Yong-Le Sun; Su-Xia Cui; Mei Chen; Hao-Meng Yang; Hui-Min Liu; Tuan-Yao Chai; Fang Huang

2011-01-01

191

The leguminous species Anthyllis vulneraria as a Zn-hyperaccumulator and eco-Zn catalyst resources.  

PubMed

Anthyllis vulneraria was highlighted here as a Zn-hyperaccumulator for the development of a pilot phytoextraction process in the mine site of Les Avinières in the district of Saint-Laurent-Le-Minier. A. vulneraria appeared to hyperaccumulate the highest concentration of Zn in shoots with a better metal selectivity relative to Cd and Pb than the reference Zn-hyperaccumulator Noccea caerulescens. A bigger biomass production associated to a higher Zn concentration conducted A. vulneraria to the highest total zinc gain per hectare per year. As a legume, A. vulneraria was infected by rhizobia symbionts. Inoculation of A. vulneraria seeds showed a positive impact on Zn hyperaccumulation. A large-scale culture process of symbiotic rhizobia of A. vulneraria was investigated and optimized to allow large-scale inoculation process. Contaminated shoots of A. vulneraria were not considered as wastes and were recovered as Eco-Zn catalyst in particular, examples of organic synthesis, electrophilic aromatic substitution. Eco-Zn catalyst was much more efficient than conventional catalysts and allowed greener chemical processes. PMID:25253057

Grison, Claire M; Mazel, Marine; Sellini, Amandine; Escande, Vincent; Biton, Jacques; Grison, Claude

2014-09-25

192

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

E-print Network

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 collected from an industrial site contaminated with Zn and Cd located in Auby (59, France). Each sample

Paris-Sud XI, Université de

193

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

PubMed Central

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

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

194

Journal of Chromatography A, 1043 (2004) 249254 Arsenic complexes in the arsenic hyperaccumulator  

E-print Network

Journal of Chromatography A, 1043 (2004) 249­254 Arsenic complexes in the arsenic hyperaccumulator-exchange chromatography­hydride generation­atomic fluorescence spectroscopy and size-exclusion chromatographyIII-tris-thiolate complexes through thiolate bonds by us- ing size-exclusion chromatography (SEC) or electrospray ionization

Ma, Lena

195

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

PubMed

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

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

2006-09-01

196

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...

197

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

Microsoft Academic Search

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

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

2008-01-01

198

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

PubMed

• 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

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

2012-04-01

199

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

NASA Astrophysics Data System (ADS)

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.

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

2009-08-01

200

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

PubMed Central

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

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

2014-01-01

201

Tolerance, accumulation and distribution of zinc and cadmium in hyperaccumulator Potentilla griffithii  

Microsoft Academic Search

In this study, zinc (Zn) and cadmium (Cd) tolerance, accumulation and distribution was conducted in Potentilla griffithii H., which has been identified as a new Zn hyperaccumulator found in China. Plants were grown hydroponically with different levels of Zn2+ (20, 40, 80 and 160mgL?1) and Cd2+ (5, 10, 20 and 40mgL?1) for 60 days. All plants grew healthy and attained

Peng-Jie Hu; Rong-Liang Qiu; Palaninaicker Senthilkumar; Dan Jiang; Zhong-Wei Chen; Ye-Tao Tang; Feng-Jie Liu

2009-01-01

202

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

Microsoft Academic Search

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

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

2004-01-01

203

Characterization of arsenic-resistant bacteria from the rhizosphere of arsenic hyperaccumulator Pteris vittata  

Microsoft Academic Search

Arsenic hyperaccumulator fern Pteris vittata L. produces large amounts of root exudates that are hypothesized to solubilize arsenic and maintain a unique rhizosphere microbial community. Total heterotrophic counts on rich or defined media supplemented with up to 400 mmol\\/L of arsenate showed a diverse arsenate-resistant microbial community from the rhizosphere of P. vittata growing in arsenic-contaminated sites. Twelve bacterial isolates

Anhui Huang; Max Teplitski; Bala Rathinasabapathi; Lena Ma

2010-01-01

204

Spatial distribution, localization, and speciation of arsenic in the hyperaccumulating fern Pteris vittata L  

Microsoft Academic Search

This study is concerned with the distribution, localization, and speciation of arsenic (As) in the hyperaccumulating fern Pteris vittata L. Sections across an intact pinnae, stipe, and root were taken from plants grown in soil treated with 1% or 200ppm As. Arsenic distribution and speciation in plant material were examined with micro-focused X-rays and X-ray absorption near-edge structure (XANES). In

B. R. Bondada; R. S. Underhill; L. Q. Ma; Y. Guyodo; A. Mikhaylova; M. R. Davidson; R. S. Duran

2007-01-01

205

A Novel Arsenate Reductase from the Arsenic Hyperaccumulating Fern Pteris vittata  

Microsoft Academic Search

Pteris vittata sporophytes hyperaccumulate arsenic to 1% to 2% of their dry weight. Like the sporophyte, the gametophyte was found to reduce arsenate (As(V)) to arsenite (As(III)) and store arsenic as free As(III). Here, we report the isolation of an arsenate reductase gene (PvACR2) from gametophytes that can suppress the arsenate sensitivity and arsenic hyperaccumu- lation phenotypes of yeast (Saccharomyces

Danielle R. Ellis; Luke Gumaelius; Emily Indriolo; Ingrid J. Pickering; Jo Ann Banks; David E. Salt

2006-01-01

206

Flowering stage characteristics of cadmium hyperaccumulator Solanum nigrum L. and their significance to phytoremediation  

Microsoft Academic Search

The Cd accumulation and biomass characteristics of a newly found Cd-hyperaccumulator Solanum nigrum L. were investigated at the flowering stage and the mature stage. The results showed that the concentration of Cd in the stems and leaves of S. nigrum harvested at the flowering stage was up to 83.1% and 85.5% of that at the mature stage, and the dry-weight

Shuhe Wei; Qixing Zhou; Pavel V. Koval

2006-01-01

207

Protective effects of proline against cadmium toxicity in micropropagated hyperaccumulator, Solanum nigrum L  

Microsoft Academic Search

Solanum nigrum is a newly discovered Cd-hyperaccumulator. In the present study, the protective effects of proline against cadmium toxicity\\u000a of callus and regenerated shoots of S. nigrum are investigated based on a high frequency in vitro shoot regeneration system. Proline pretreatment reduces the reactive\\u000a oxygen species levels and protects the plasma membrane integrity of callus under cadmium stress, and therefore

Jin Xu; HengXia Yin; Xia Li

2009-01-01

208

Effects of cadmium hyperaccumulation on the concentrations of four trace elements in Lonicera japonica Thunb  

Microsoft Academic Search

Hyperaccumulators are important in the phytoremediation of cadmium (Cd)-contaminated soil. In this study, Cd accumulation\\u000a and the interactions between Cd and four other trace elements (Fe, Mn, Cu, and Zn) in Lonicera japonica Thunb. were investigated. As a result of exposure to soil containing 50 mg kg?1 Cd, stem and shoot Cd concentrations reached 344.49 ± 0.71 and 286.12 ± 9.38 ?g g?1 DW respectively, without showing symptoms

Zhouli LiuXingyuan; Xingyuan He; Wei Chen

2011-01-01

209

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

Microsoft Academic Search

.   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

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

2000-01-01

210

A novel arsenate reductase from the arsenic hyperaccumulating fern Pteris vittata.  

PubMed

Pteris vittata sporophytes hyperaccumulate arsenic to 1% to 2% of their dry weight. Like the sporophyte, the gametophyte was found to reduce arsenate [As(V)] to arsenite [As(III)] and store arsenic as free As(III). Here, we report the isolation of an arsenate reductase gene (PvACR2) from gametophytes that can suppress the arsenate sensitivity and arsenic hyperaccumulation phenotypes of yeast (Saccharomyces cerevisiae) lacking the arsenate reductase gene ScACR2. Recombinant PvACR2 protein has in vitro arsenate reductase activity similar to ScACR2. While PvACR2 and ScACR2 have sequence similarities to the CDC25 protein tyrosine phosphatases, they lack phosphatase activity. In contrast, Arath;CDC25, an Arabidopsis (Arabidopsis thaliana) homolog of PvACR2 was found to have both arsenate reductase and phosphatase activities. To our knowledge, PvACR2 is the first reported plant arsenate reductase that lacks phosphatase activity. CDC25 protein tyrosine phosphatases and arsenate reductases have a conserved HCX5R motif that defines the active site. PvACR2 is unique in that the arginine of this motif, previously shown to be essential for phosphatase and reductase activity, is replaced with a serine. Steady-state levels of PvACR2 expression in gametophytes were found to be similar in the absence and presence of arsenate, while total arsenate reductase activity in P. vittata gametophytes was found to be constitutive and unaffected by arsenate, consistent with other known metal hyperaccumulation mechanisms in plants. The unusual active site of PvACR2 and the arsenate reductase activities of cell-free extracts correlate with the ability of P. vittata to hyperaccumulate arsenite, suggesting that PvACR2 may play an important role in this process. PMID:16766666

Ellis, Danielle R; Gumaelius, Luke; Indriolo, Emily; Pickering, Ingrid J; Banks, Jo Ann; Salt, David E

2006-08-01

211

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

PubMed Central

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

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

212

[Characteristics of 23 species of weed in northeast of China hyperaccumulating PAHs in contaminated soils].  

PubMed

Pot experiments were conducted to investigate the 23 species of weed accumulation characteristics of phenanthrene, as a representative of polycyclic aromatic hydrocarbons (PAHs), from soil in the northeast of China. The result indicated that among the 23 species, the bioconcentration factors of Taraxacum ohwianum K., Potentilla aiscolor B. and Chelidonium majus L. were all higher than 1, which were 1.01, 4.98, 38.24 respectively. The phenanthrene concentrations in roots were 2.83, 16.34 and 9.66 mg/kg which were lower than those in aboveground part with phenanthrene concentrations were 15.18, 74.70 and 573.62 mg/kg, respectively. The hyperaccumulators were indicated by strong conveyance of phenanthrene from root to aboveground part. The analysis of phenanthrene concentration in aboveground weed and aboveground plant biomass showed that the accumulation of phenanthrene in plant were not correlated with their biomass. It concluded that Taraxacum ohwianum K., Potentilla aiscolor B. and Chelidonium majus L. had hyperaccumulative characteristics of phenanthrene, and it is possible to screen out plants with high biomass and hyperaccumulation capability. PMID:22279928

Zhang, Min; Liang, Hong; Gao, Da-Wen; Zhang, Bai-Hui; Li, Xin-Ping; Guo, Xiao-Hu

2011-10-01

213

Response of ATP sulfurylase and serine acetyltransferase towards cadmium in hyperaccumulator Sedum alfredii Hance*  

PubMed Central

We studied the responses of the activities of adenosine-triphosphate (ATP) sulfurylase (ATPS) and serine acetyltransferase (SAT) to cadmium (Cd) levels and treatment time in hyperaccumulating ecotype (HE) Sedum alfredii Hance, as compared with its non-hyperaccumulating ecotype (NHE). The results show that plant growth was inhibited in NHE but promoted in HE when exposed to high Cd level. Cd concentrations in leaves and shoots rapidly increased in HE rather than in NHE, and they became much higher in HE than in NHE along with increasing treatment time and Cd supply levels. ATPS activity was higher in HE than in NHE in all Cd treatments, and increased with increasing Cd supply levels in both HE and NHE when exposed to Cd treatment within 8 h. However, a marked difference of ATPS activity between HE and NHE was found with Cd treatment for 168 h, where ATPS activity increased in HE but decreased in NHE. Similarly, SAT activity was higher in HE than in NHE at all Cd treatments, but was more sensitive in NHE than in HE. Both ATPS and SAT activities in NHE leaves tended to decrease with increasing treatment time after 8 h at all Cd levels. The results reveal the different responses in sulfur assimilation enzymes and Cd accumulation between HE and NHE. With increasing Cd stress, the activities of sulfur assimilation enzymes (ATPS and SAT) were induced in HE, which may contribute to Cd accumulation in the hyperaccumulator Sedum alfredii Hance. PMID:19353742

Guo, Wei-dong; Liang, Jun; Yang, Xiao-e; Chao, Yue-en; Feng, Ying

2009-01-01

214

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

PubMed

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

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

2014-01-01

215

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

SciTech Connect

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).

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

2007-01-01

216

Effects of cadmium hyperaccumulation on the concentrations of four trace elements in Lonicera japonica Thunb.  

PubMed

Hyperaccumulators are important in the phytoremediation of cadmium (Cd)-contaminated soil. In this study, Cd accumulation and the interactions between Cd and four other trace elements (Fe, Mn, Cu, and Zn) in Lonicera japonica Thunb. were investigated. As a result of exposure to soil containing 50 mg kg(-1) Cd, stem and shoot Cd concentrations reached 344.49 ± 0.71 and 286.12 ± 9.38 ?g g(-1) DW respectively, without showing symptoms of visible damage to the plants. This suggests that L. japonica has a strong tolerance to Cd. It is proposed that trace metal elements are involved in the Cd-detoxification mechanisms shown by hyperaccumulators. There is a synergistic interaction in accumulation and translocation between Cd and Fe and a significantly negative correlation between Cd and Cu or Zn concentrations in L. japonica plant tissues. The imbalanced trace element concentrations influences detoxification processes to Cd, therefore, L. japonica could be considered as a new Cd-hyperaccumulator model to investigate the metal tolerance strategies of plants. PMID:21318389

Liu, Zhouli; He, Xingyuan; Chen, Wei

2011-06-01

217

Increase of glutathione in mine population of Sedum alfredii: a Zn hyperaccumulator and Pb accumulator.  

PubMed

Phytochelatins (PCs) have been induced in a large range of plant species, but their role in heavy metal tolerance is unclear. Sedum alfredii is a new zinc (Zn) hyperaccumulator and lead (Pb) accumulator found in an old Pb/Zn mine in the Zhejiang Province of China. Until now, the mechanisms of its hyperaccumulation/accumulation and tolerance were poorly understood. The aim of this work was to investigate whether PCs were differentially produced in mine populations of S. alfredii compared with a non-mine control of the same species. The results showed that plants from the mine site were more tolerant to increasing Zn and Pb concentrations than those from the control site. No PCs and cysteine (Cys) were detected by pre-column derivatization with HPLC fluorescence in any tissues of two populations at any treatment, which in turn indicated they were not responsible for Zn and Pb tolerance in the mine population. Instead, Zn and Pb treatments resulted in the increase of glutathione (GSH) for both populations in a tissue-dependent manner. Significant increases were observed in leaf, stem and root tissues of plants grown on the mine site. The results suggest that GSH, rather man PCs, may be involved in Zn and Pb transport, hyperaccumulation/accumulation and tolerance in mine population of S. alfredii. PMID:16225897

Sun, Q; Ye, Z H; Wang, X R; Wong, M H

2005-11-01

218

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

PubMed Central

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

Verbruggen, Nathalie; Hanikenne, Marc; Clemens, Stephan

2013-01-01

219

Effect of soil properties on arsenic hyperaccumulation in Pteris vittata and Pityrogramma calomelanos var. austroamericana.  

PubMed

Two arsenic (As) hyperaccumulators, Pteris vittata L. and Pityrogramma calomelanos var. austroamericana, were grown in As-contaminated soils of contrasting properties. Ferns were exposed to three levels of As in soil at concentrations of 0,600 and 2400 micromol kg(-1) for a period of 22 weeks. Plant biomass and As concentration in fronds and roots varied significantly between the two species. At 600 micromol kg(-1) As level, As hyperaccumulation was not observed in both the fern species. However at the 2400 micromol kg(-1) As level, both the species accumulated very high levels (> 1000 mg kg(-1)) of As in fronds. Arsenic concentration and uptake in fronds of both species followed the order Kurosol (Box Hill) > Vertosol (Narrabri) > Ferrosol (Robertson). In the studied soils, P. vittata possessed higher frond biomass and As accumulation, and thus was more efficient in removing soil As than P. calomelanos var. austroamericana. Soil properties such as free Fe, clay and organic matter contents appear to have affected the bioavailability of As in the studied soils. These results show that soil properties influence the As extraction efficiency of hyperaccumulating plants and must be considered in context of the phytoextraction technology of As contaminated soils. PMID:20734614

Xu, Weihong; Kachenko, Anthony George; Singh, Balwant

2010-02-01

220

Interactive effects of pH, arsenic and phosphorus on uptake of As and P and growth of the arsenic hyperaccumulator Pteris  

E-print Network

hyperaccumulator Pteris vittata L. under hydroponic conditions S. Tu, L.Q. Ma * Soil and Water Science Department, especially water. Two sets of hydroponic experiments were conducted using three-factor, five-level central design; Hydroponics; Hyperaccumulation; Pteris vittata L. 1. Introduction In recent years, arsenic (As

Ma, Lena

221

Synergistic effects of arbuscular mycorrhizal fungi and phosphate rock on heavy metal uptake and accumulation by an arsenic hyperaccumulator.  

PubMed

The effects of arbuscular mycorrhizal (AM) fungi and phosphate rock on the phytorextraction efficiency of a hyperaccumulator (Pteris vittata) and a non-hyperaccumulator (Cynodon dactylon) plant were studied. Both seedlings were planted in As contaminated soil under different treatments [(1) control (contaminated soil only), (2) indigenous mycorrhizas (IM), (3) mixed AM inoculum [indigenous mycorrhiza + Glomus mosseae (IM/Gm)] and (4) IM/Gm + phosphate rock (P rock)] with varying intensities (40%, 70% and 100%) of water moisture content (WMC). Significant As reduction in soil (23.8% of soil As reduction), increase in plant biomass (17.8 g/pot) and As accumulation (2054 mg/kg DW) were observed for P. vittata treated with IM/Gm + PR at 100% WMC level. The overall results indicated that the synergistic effect of mycorrhiza and P rock affected As subcellular distribution of the hyperaccumulator and thereby altered its As removal efficiency under well-watered conditions. PMID:20541316

Leung, H M; Wu, F Y; Cheung, K C; Ye, Z H; Wong, M H

2010-09-15

222

Extraction and isolation of the salidroside-type metabolite from zinc (Zn) and cadmium (Cd) hyperaccumulator Sedum alfredii Hance*  

PubMed Central

The active metabolite in the post-harvested biomass of zinc (Zn) and cadmium (Cd) hyperaccumulator Sedum alfredii Hance from phytoextraction is of great interest in China. The current study demonstrates that a salidroside-type metabolite can be yielded from the Zn/Cd hyperaccumulator S. alfredii biomass by means of sonication/ethanol extraction and macroporous resin column (AB-8 type) isolation. The concentrations of Zn and Cd in the salidroside-type metabolite were below the limitation of the national standards. PMID:23024051

Xing, Yan; Peng, Hong-yun; Li, Xia; Zhang, Meng-xi; Gao, Ling-ling; Yang, Xiao-e

2012-01-01

223

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

PubMed Central

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

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

224

Simultaneous hyperaccumulation of arsenic and antimony in Cretan brake fern: Evidence of plant uptake and subcellular distributions  

Microsoft Academic Search

Arsenic (As) and antimony (Sb) show similar chemical properties and often present together in sulfide ores. Currently, phenomenon of co-contamination of As and Sb at some sites of the world has been increasingly emerged. The present study was conducted to explore the potential of Pteris cretica L. (Cretan brake fern), an arsenic (As) hyperaccumulator, to simultaneously accumulate As and Sb

Renwei Feng; Chaoyang Wei; Shuxin Tu; Shirong Tang; Fengchang Wu

2011-01-01

225

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

Microsoft Academic Search

Low molecular weight thiol-containing compounds have been reported to play an important role in metal detoxification and accumulation in some higher plants. The formation of these low molecular weight thiols in the recently discovered arsenic hyperaccumulator, Chinese Brake fern (Pteris vittata) upon exposure to arsenic and other trace metals was investigated. In addition to cysteine and glutathione, an unidentified thiol

Yong Cai; Jinhui Su; Lena Q. Ma

2004-01-01

226

Characterization of Arsenate Reductase in the Extract of Roots and Fronds of Chinese Brake Fern, an Arsenic Hyperaccumulator  

Microsoft Academic Search

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

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

2005-01-01

227

Influence of the arbuscular mycorrhizal fungus Glomus mosseae on uptake of arsenate by the As hyperaccumulator fern Pteris vittata L  

Microsoft Academic Search

We report for the first time some effects of colonization by an arbuscular mycorrhizal (AM) fungus (Glomus mosseae) on the biomass and arsenate uptake of an As hyperaccumulator, Pteris vittata. Two arsenic levels (0 and 300 mg As kg-1) were applied to an already contaminated soil in pots with two compartments for plant and hyphal growth in a glasshouse experiment. Arsenic

Y. Liu; Y. G. Zhu; B. D. Chen; P. Christie; X. L. Li

2005-01-01

228

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

NASA Astrophysics Data System (ADS)

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.

Cui, Shuang; Zhou, Qixing; Chao, Lei

2007-01-01

229

Do High-nickel Leaves Shed by the Ni-hyperaccumulator Alyssum Murale Inhibit Seed Germination of Competing Plants?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Elemental allelopathy suggests that nickel (Ni)-rich leaves shed by hyperaccumulators inhibit the germination and growth of nearby plant species. Here, the germination of eight herbaceous species following addition of Alyssum murale biomass or Ni(NO3)2, with the same Ni level added to soil, was ass...

230

ReproducedfromJournalofEnvironmentalQuality.PublishedbyASA,CSSA,andSSSA.Allcopyrightsreserved. Mycorrhizae Increase Arsenic Uptake by the Hyperaccumulator  

E-print Network

JournalofEnvironmentalQuality.PublishedbyASA,CSSA,andSSSA.Allcopyrightsreserved. Mycorrhizae Increase Arsenic Uptake by the Hyperaccumulator Chinese Brake Fern (Pteris vittata L.) Abid Al alteration of the rhizosphere­hyphosphere, increasedChinese brake fern (Pteris vittata L concentrations. (Pteris vittata L.; Ma et al., 2001) and several other fern species (Raab et al., 2004; Meharg

Ma, Lena

231

Nickel and Manganese Accumulation, Interaction and Localization in Leaves of the Ni Hyperaccumulators Alyssum murale and Alyssum corsicum  

Technology Transfer Automated Retrieval System (TEKTRAN)

The genus Alyssum contains >50 Ni hyperaccumulator species; many can achieve 3% Ni in dry leaf. In soils with normal Mn levels, Alyssum trichome bases were observed previously to accumulate Ni and Mn to high levels. Here we report concentration and localization patterns in A. murale and A. corsicum...

232

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

E-print Network

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

Ma, Lena

233

Moderate phosphorus application enhances Zn mobility and uptake in hyperaccumulator Sedum alfredii.  

PubMed

While phytoextraction tools are increasingly applied to remediation of contaminated soils, strategies are needed to optimize plant uptake by improving soil conditions. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. Microcosm experiments were conducted in greenhouse to examine the effect of different phosphorus (P) sources on zinc (Zn) phytoextraction by Sedum alfredii in aged Zn-contaminated paddy soil. The Zn accumulation, soil pH, microbial biomass and enzyme activity, available Zn changes. and Zn phytoremediation efficiency in soil after plant harvest were determined. Upon addition of P, Zn uptake of S. alfredii significantly increased. Mehlich-3 extractable or the fractions of exchangeable and carbonate-bound soil Zn were significantly increased at higher P applications. Soil pH significantly decreased with increasing P application rates. Soil microbial biomass in the P-treated soils was significantly higher (P < 0.05) than those in the control. Shoot Zn concentration was positively correlated with Mehlich-3 extractable P (P < 0.0001) or exchangeable/carbonate-bound Zn (P < 0.001), but negatively related to soil pH (P < 0.0001). These results indicate that application of P fertilizers has the potential to enhance Zn mobility and uptake by hyperaccumulating plant S. alfredii, thus increasing phytoremediation efficiency of Zn-contaminated soils. PMID:22992988

Huang, Huagang; Wang, Kai; Zhu, Zhiqiang; Li, Tingqiang; He, Zhenli; Yang, Xiao-E; Gupta, D K

2013-05-01

234

Arsenic complexes in the arsenic hyperaccumulator Pteris vittata (Chinese brake fern).  

PubMed

Pteris vittata (Chinese brake fern), the first reported arsenic (As) hyperaccumulating plant, can be potentially applied in the phytoremediation As-contaminated sites. Understanding the mechanisms of As tolerance and detoxification in this plant is critical to further enhance its capability of As hyperaccumulation. In this study, an unknown As species, other than arsenite (AsIII) or arsenate (AsV) was found in leaflets by using anion-exchange chromatography-hydride generation-atomic fluorescence spectroscopy and size-exclusion chromatography-atomic fluorescence spectrometry. The chromatographic behavior of this unknown As species and its stability suggest that it is likely an As complex. Although phytochelatin with two subunits (PC2) was the only major thiol in P. vittata under As exposure, this unknown As complex was unlikely to be an AsIII-PC2 complex by comparison of their chromatographic behaviors, stability at different pHs and charge states. The complex is sensitive to temperature and metal ions, but relatively insensitive to pH. In buffer solution of pH 5.9, it is present in a neutral form. PMID:15330099

Zhang, Weihua; Cai, Yong; Downum, Kelsey R; Ma, Lena Q

2004-07-23

235

A quantitative trait loci analysis of zinc hyperaccumulation in Arabidopsis halleri.  

PubMed

The mechanisms of metal hyperaccumulation are still not understood, so we conducted a quantitative trait locus (QTL) analysis of zinc (Zn) hyperaccumulation in Arabidopsis halleri, in a cross between this and its sister species, A. petraea, in order to determine the number and approximate location of the genomic regions significantly contributing to this adaptation. An F2 cross between the two species was made, and the leaf Zn concentration of 92 individuals was measured at both low (10 microm) and high (100 microm) Zn concentrations. Twenty-five markers were established that were distributed on all of the eight chromosomes. Mapping of the markers established that they were essentially collinear with previous studies. QTLs exceeding a logarithm to the base 10 of the odds (LOD) value of 3 were found on chromosomes 4 (low Zn), 6 (high Zn) and 7 (both high and low Zn). Evidence for a QTL on chromosome 3 (low Zn) was also found. This analysis validates a previously used method of QTL analysis, based on microarray analysis of segregating families. Genes that have altered during the evolution of this character should also be QTL: this analysis calls into question a number of candidate genes from consideration as such primary genes because they do not appear to be associated with QTLs. PMID:17447913

Filatov, Victor; Dowdle, John; Smirnoff, Nicholas; Ford-Lloyd, Brian; Newbury, H John; Macnair, Mark R

2007-01-01

236

Cellular Sequestration of Cadmium in the Hyperaccumulator Plant Species Sedum alfredii  

SciTech Connect

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.

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

237

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

PubMed Central

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

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

2011-01-01

238

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

SciTech Connect

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.

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

2006-09-01

239

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

PubMed Central

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

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

2006-01-01

240

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

PubMed Central

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

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

2013-01-01

241

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

242

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

PubMed Central

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.

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

2015-01-01

243

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

PubMed

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

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

2014-08-21

244

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

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

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

2014-01-01

245

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

SciTech Connect

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.

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

2007-10-08

246

Evaluation of hyperaccumulator plant species grown in metalliferous sites in Albania  

NASA Astrophysics Data System (ADS)

Heavy metal contamination of soils causes serious problems to our society. A small number of interesting plant species have been identified that can grow in soils containing high levels of heavy metals, and can also accumulate these metals to high concentrations in the shoot. The heavy metal contents in root, shoot, leaves and flowers of spontaneous plants grown in metalliferous sites in Albania together with the elemental composition of the native soils were determined by X-ray fluorescence spectrometry. Efficiency of photosynthetic apparatus of analyzed ecotypes was evaluated via chlorophyll fluorescence imaging during induction kinetics. Response of plant root system to the presence of metals, the available pools of metals to plants, effect of plant biomass to phytoextraction, photosynthetic pigment metabolism and chlorophyll fluorescence signature of leaves allowed to characterize hyperaccumulator properties and to detect the variation between selected ecotypes to heavy metal accumulation.

Babani, F.; Civici, N.; Mullaj, A.; Kongjika, E.; Ylli, A.

2007-04-01

247

Manganese uptake and interactions with cadmium in the hyperaccumulator--Phytolacca Americana L.  

PubMed

In the present study, the accumulation of Mn and other metals by Phytolacca Americana L. from contaminated soils in Hunan Province, South China, was investigated. Results showed that the average concentrations of Mn in the leaves and roots reached 2198 and 80.4 mg kg(-1) (dry weight), respectively, with a maximum 13,400 mg kg(-1) in the leaves. A significant correlation was found between Mn concentrations in the plant leaves and those in the corresponding soils. Hydroponic experiments were also conducted to study the Cd uptake ability and interactions between Mn and Cd in the plant. It was found that P. americana hyperaccumulated not only Mn, but also Cd in the leaves. In the presence of Cd, adding Mn to the solution significantly improved the plant growth and reduced the concentrations of Cd in all organs of the plant. PMID:18068296

Peng, Kejian; Luo, Chunling; You, Wuxin; Lian, Chunlan; Li, Xiangdong; Shen, Zhenguo

2008-06-15

248

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

PubMed Central

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

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

2002-01-01

249

Effect of different nitrogenous nutrients on the cadmium hyperaccumulation efficiency of Rorippa globosa (Turcz.) Thell.  

PubMed

This experiment was used to explore whether the 11 nitrogenous nutrients affect the hyperaccumulation of Rorippa globosa (Turcz.) Thell. to Cd. Pot culture experiments using soil spiked with Cd as CdCl2·2.5H2O and 11 nitrogen-containing chemicals were conducted to determine the efficiency of the accumulation of Cd by R. globosa. Application of all 11 nitrogenous nutrients significantly (p??phosphate?>?chloride compounds of NH4 enhanced the biomass yield to the greatest extent, while oxalate?>?nitrate?>?chloride?>?and bicarbonate caused a significant increase of Cd uptake by R. globosa. Competition between N and Cd translocation caused either significant reduction of Cd translocation factor or decrease of biomass yield. Of studied nutrients, ammonium bicarbonate NH4HCO3 and ammonium chloride NH4Cl exerted the best joint effect of these two processes on the efficiency of R. globosa as a Cd hyperaccumulator. Application of these chemicals caused increase of Cd concentrations in roots of R. globosa by 35.1 and 41.1 %, and in shoots by 13.9 and 56.4 %, while biomasses of roots increased by 5.8- and 3.8-fold and in shoots by 7.4-fold, and 6.4-fold, respectively, compared to the control. As a result, accumulated load (?g pot(-1)) of Cd in roots increased by 8.2- and 5.8-fold and in shoots by 8.6- and 10.6-fold in both pots. Consequently, chemicals (NH4HCO3 and NH4Cl) that enhanced both Cd enrichment and biomass yield had the greatest effect on the bioaccumulation capacity of R. globosa. PMID:25167813

Wei, Shuhe; Ji, Dandan; Twardowska, Irena; Li, Yunmeng; Zhu, Jiangong

2015-02-01

250

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

PubMed Central

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

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

2014-01-01

251

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

252

Development of eight polymorphic microsatellite markers by FIASCO-based strategy for a arsenic-hyperaccumulator Chinese brake fern  

Microsoft Academic Search

Chinese Brake fern (Pteris vittata) is the first identified and well-known arsenic-hyperaccumulator. It is widely distributed in areas of temperate zone as\\u000a diploid and of subtropics-tropics zone as tetraploid. Screening 60 individuals from Southern China, eight polymorphic microsatellite\\u000a markers were developed for the first time by employing fast isolation by AFLP of sequences containing repeats protocol (FIASCO).\\u000a The number of

B. Yang; M. Hu; M. Zhou; J. P. Guan; J. Zhang; C. Y. Lan; B. Liao

2010-01-01

253

Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator, Pteris vittata L  

Microsoft Academic Search

Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated–copper–arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil.

Xinde Cao; Lena Q. Ma; Aziz Shiralipour

2003-01-01

254

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

Microsoft Academic Search

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

Kevin Francesconi; Pornsawan Visoottiviseth; Weeraphan Sridokchan; Walter Goessler

2002-01-01

255

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

Microsoft Academic Search

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

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

2011-01-01

256

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

PubMed

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

Freeman, John L; Bañuelos, Gary S

2011-11-15

257

Difference of toxicity and accumulation of methylated and inorganic arsenic in arsenic-hyperaccumulating and -hypertolerant plants.  

PubMed

The arsenic (As) hyperaccumulators, Pteris vittata and Pteris cretica and an As-tolerant plant Boehmeria nivea, were selected to compare the toxicity, uptake, and transportation of inorganic arsenate (As(V)) and its methylated counterpart dimethylarsinic acid (DMA). The XANES method was used to elucidate the effect of As species transformation on As toxicity and accumulation characteristics. Significantly higher toxicity and lower accumulation of DMAthan inorganic As(V) was shown in the As hyperaccumulators and the As-tolerant plant. Reduction of As(V) was commonly found in the plants. Arsenic complexation with thiols, which have less mobility in plants and usually occur in As-tolerant plants, was also found in rhizoids of P. cretica. Plants with greater ability to form As-thiolate have lower ability for upward transport of As. Demethylation of DMA occurred in the three plants. The DMA component decreased from the rhizoids to the fronds in both hyperaccumulators, while this tendency is reverse in B. nivea. PMID:18754355

Huang, Ze-Chun; Chen, Tong-Bin; Lei, Mei; Liu, Ying-Ru; Hu, Tian-Dou

2008-07-15

258

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

PubMed

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

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

2013-10-15

259

Simultaneous compartmentalization of lead and arsenic in co-hyperaccumulator Viola principis H. de Boiss.: an application of SRXRF microprobe.  

PubMed

The cellular distributions of Pb and As in the leaves of co-hyperaccumulator Viola principis H. de Boiss. were inspected by synchrotron X-ray fluorescence spectroscopy (SRXRF). The results revealed that Pb and As had similar compartmentalization patterns in the leaves. Both elements were enriched in the bundle sheath and the palisade mesophyll. In comparison with the sheath and the mesophyll, the vascular bundle and the epidermis contained lower levels of Pb and As. The palisade enrichment of Pb and As indicated that V. principis H. de Boiss. may have a special mechanism on detoxification of toxic metals within the mesophyll cells. Relative concentrations of both Pb and As in trichome bases were higher than those in trichome rays. The results of hierarchical cluster analysis and correlation analysis confirmed that the distribution of Pb was similar to that of As in the leaves, and their distribution patterns were different from the nutrient elements, such as K, Ca, Mn, Fe, Ni, Cu and Zn. In vivo cellular localization of Pb and As in the leaves provides insight into the physiological mechanisms of metal tolerance and hyperaccumulation in the hyperaccumulators. PMID:18571691

Lei, Mei; Chen, Tong-Bin; Huang, Ze-Chun; Wang, Yao-Dong; Huang, Yu-Ying

2008-08-01

260

The metal transporter PgIREG1 from the hyperaccumulator Psychotria gabriellae is a candidate gene for nickel tolerance and accumulation.  

PubMed

Nickel is an economically important metal and phytotechnologies are being developed to limit the impact of nickel mining on the environment. More than 300 plant species are known to hyperaccumulate nickel. However, our knowledge of the mechanisms involved in nickel accumulation in plants is very limited because it has not yet been possible to study these hyperaccumulators at the genomic level. Here, we used next-generation sequencing technologies to sequence the transcriptome of the nickel hyperaccumulator Psychotria gabriellae of the Rubiaceae family, and used yeast and Arabidopsis as heterologous systems to study the activity of identified metal transporters. We characterized the activity of three metal transporters from the NRAMP and IREG/FPN families. In particular, we showed that PgIREG1 is able to confer nickel tolerance when expressed in yeast and in transgenic plants, where it localizes in the tonoplast. In addition, PgIREG1 shows higher expression in P. gabriellae than in the related non-accumulator species Psychotria semperflorens. Our results designate PgIREG1 as a candidate gene for nickel tolerance and hyperaccumulation in P. gabriellae. These results also show how next-generation sequencing technologies can be used to access the transcriptome of non-model nickel hyperaccumulators to identify the underlying molecular mechanisms. PMID:24510940

Merlot, Sylvain; Hannibal, Laure; Martins, Sara; Martinelli, Laëtitia; Amir, Hamid; Lebrun, Michel; Thomine, Sébastien

2014-04-01

261

Mycorrhizal colonization affects the elemental distribution in roots of Ni-hyperaccumulator Berkheya coddii Roessler.  

PubMed

The effect of arbuscular mycorrhizal fungi (AMF) on the distribution and concentration of elements in roots of Ni-hyperaccumulating plant Berkheya coddii was studied. Micro-PIXE (particle-induced X-ray emission) analysis revealed significant differences between AMF-inoculated and non-inoculated plants as well as between main and lateral roots. The accumulation of P, K, Mn and Zn in the cortical layer of lateral roots of inoculated plants confirmed the important role of AMF in uptake and accumulation of these elements. Higher concentration of P, K, Fe, Ni, Cu and Zn in the vascular stele in roots of AMF-inoculated plants than in the non-inoculated ones indicates more efficient translocation of these elements to the aboveground parts of the plant. These findings indicate the necessity of including the influence of AMF in studies on the uptake of elements by plants and in industrial use of B. coddii for Ni extraction from polluted soils. PMID:23369753

Or?owska, El?bieta; Przyby?owicz, Wojciech; Orlowski, Dariusz; Mongwaketsi, Nametso P; Turnau, Katarzyna; Mesjasz-Przyby?owicz, Jolanta

2013-04-01

262

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

PubMed

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

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

2014-10-01

263

Nickel and cobalt phytoextraction by the hyperaccumulator Berkheya coddii: implications for polymetallic phytomining and phytoremediation.  

PubMed

We investigated the potential of the South African high-biomass Ni hyperaccumulator Berkheya coddii to phytoextract Co and/or Ni from artificial metalliferous media. Plant accumulation of both metals from single-element substrates indicate that the plant/media metal concentration quotient (bioaccumulation coefficient) increases as total metal concentrations increase. Cobalt was readily taken up by B. coddii with and without the presence of Ni. Nickel uptake was, however, inhibited by the presence of an equal concentration of Co. Bioaccumulation coefficients of Ni and Co for the single element substrates (total metal concentration of 1000 micrograms g-1) were 100 and 50, respectively. Cobalt phytotoxicity was observed above a total Co concentration in plant growth media of 20 micrograms g-1. Elevated Co concentrations significantly decreased the biomass production of B. coddii without affecting the bioaccumulation coefficients. The mixed Ni-Co substrate produced bioaccumulation coefficients of 22 for both Ni and Co. Cobalt phytotoxicity in mixed Ni-Co substrate occurred above a total Co concentration of 15 micrograms g-1. When grown in the presence of both Ni and Co, the bioaccumulation coefficients of each metal were reduced, as compared to single-element substrate. This may indicate competition for binding sites in the root zone. The interference relationship between Ni and Co uptake demonstrated by B. coddii suggests a significant limitation to phytoextraction where both metals are present. PMID:14750431

Keeling, S M; Stewart, R B; Anderson, C W; Robinson, B H

2003-01-01

264

Arsenic-induced morphogenic response in roots of arsenic hyperaccumulator fern Pteris vittata.  

PubMed

On the assumption that arsenic induces stress morphogenetic responses involved in As tolerance and hyperaccumulation in the Pteris vittata fern, we analyzed the root system of young sporophytes grown in 250, 334, and 500 ?M As for five days and for 14 days. Anatomical and histological analyses were performed in plants grown for five days to evaluate the number, position, length and differentiation pattern of root hairs. AgNOR staining, employed to study nucleolus behavior in root apices, showed that arsenic influences nucleolar activity (evaluated by nucleolus size, number and absorbance) in the root meristem. In plants treated with 250 and 334 ?M As an acropetal shift of root hair development and an increase in hair length and density were observed, linked to an ectopic pattern of differentiation. The opposite trend was recorded in plants treated with 500 ?M As. It is worth noting the presence of living border-like cells, not yet observed in ferns, and their increase following As treatments. Analysis and vitality of border-like cells were surveyed after 14 days of treatments. In conclusion As treatments elicited a stress-induced morphogenic response which, by modifying the differentiation pattern, number and length of root hairs, modulating nucleolar activity and interacting with the rhizosphere by inducing border-like cell production, may adjust the rate of root uptake and its metabolic activity. PMID:22906843

Forino, Laura Maria Costantina; Ruffini Castiglione, Monica; Bartoli, Giacomo; Balestri, Mirko; Andreucci, Andrea; Tagliasacchi, Anna Maria

2012-10-15

265

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

PubMed

We investigated the effects of arsenic species on As accumulation, plant growth and rhizospheric changes in As-hyperaccumulator Pteris vittata (PV). PV was grown for 60-d in a soil spiked with 200 mg kg(-1) arsenate (AsV-soil) or arsenite (AsIII-soil). Diffusive gradients in thin-films technique (DGT) were used to monitor As uptake by PV. Interestingly AsIII-soil produced the highest PV biomass at 8.6 g plant(-1), 27% and 46% greater than AsV-soil and the control. Biomass increase was associated with As-induced P uptake by PV. Although AsIII was oxidized to AsV during the experiment, As species impacted As accumulation by PV, with 17.5% more As in AsIII-soil than AsV-soil (36 vs. 31 mg plant(-1)). As concentration in PV roots was 30% higher in AsV-soil whereas As concentration in PV fronds was 7.9% greater in AsIII-soil, suggesting more rapid translocation of AsIII than AsV. These findings were important to understand the mechanisms of As uptake, accumulation and translocation by PV. PMID:25103044

Xu, Jia Yi; Li, Hong Bo; Liang, Shuang; Luo, Jun; Ma, Lena Q

2014-11-01

266

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

PubMed Central

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

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

2014-01-01

267

Effect of elevated CO2 concentration on photosynthetic characteristics of hyperaccumulator Sedum alfredii under cadmium stress.  

PubMed

The combined effects of elevated CO2 and cadmium (Cd) on photosynthetic rate, chlorophyll fluorescence and Cd accumulation in hyperaccumulator Sedum alfredii were investigated to predict plant growth under Cd stress with rising atmospheric CO2 concentration. Both pot and hydroponic experiments were conducted and the plants were grown under ambient (350?µL?L(-1) ) or elevated (800?µL?L(-1) ) CO2 . Elevated CO2 significantly (P?

Li, Tingqiang; Tao, Qi; Di, Zhenzhen; Lu, Fan; Yang, Xiaoe

2014-11-01

268

Accumulation and tolerance characteristics of cadmium in a halophytic Cd-hyperaccumulator, Arthrocnemum macrostachyum.  

PubMed

The potential of the extreme halophyte Arthrocnemum macrostachyum was examined to determine its tolerance and ability to accumulate cadmium for phytoremediation purposes. A glasshouse experiment was designed to investigate the effect of cadmium from 0 to 1.35 mmol l(-1) on the growth and the photosynthetic apparatus of A. macrostachyum by measuring chlorophyll fluorescence parameters, gas exchange and photosynthetic pigment concentrations. We also determined ash, cadmium, calcium, copper, iron, manganese, magnesium, phosphorous, sodium, and zinc concentrations, and C/N ratio. A. macrostachyum demonstrated hypertolerance to cadmium stress; it did not show phytotoxicity at shoot concentration as high as 70 mg kg(-1). The bioaccumulator factors exceeded the critical value (1.0) for all Cd treatments, and the transport factors indicated that this species has higher ability to transfer Cd from roots to shoots at lower Cd concentrations. At 1.35 mmol l(-1) Cd A. macrostachyum showed 25% biomass reduction after a month of treatment. Long-term effects of cadmium on the growth were mainly determined by variations in net photosynthetic rate (P(N)). Reductions in P(N) could be accounted by higher dark respiration and lower pigment concentrations. Finally, A. macrostachyum has the basic characteristics of a Cd-hyperaccumulator and may be useful for restoring Cd-contaminated sites. PMID:20832167

Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Andrades-Moreno, Luis

2010-12-15

269

Sulfate and glutathione enhanced arsenic accumulation by arsenic hyperaccumulator Pteris vittata L.  

PubMed

This experiment examined the effects of sulfate (S) and reduced glutathione (GSH) on arsenic uptake by arsenic hyperaccumulator Pteris vittata after exposing to arsenate (0, 15 or 30 mg As L(-1)) with sulfate (6.4, 12.8 or 25.6 mg S L(-1)) or GSH (0, 0.4 or 0.8 mM) for 2-wk. Total arsenic, S and GSH concentrations in plant biomass and arsenic speciation in the growth media and plant biomass were determined. While both S (18-85%) and GSH (77-89%) significantly increased arsenic uptake in P. vittata, GSH also increased arsenic translocation by 61-85% at 0.4 mM (p < 0.05). Sulfate and GSH did not impact plant biomass or arsenic speciation in the media and biomass. The S-induced arsenic accumulation by P. vittata was partially attributed to increased plant GSH (21-31%), an important non-enzymatic antioxidant countering oxidative stress. This experiment demonstrated that S and GSH can effectively enhance arsenic uptake and translocation by P. vittata. PMID:20045235

Wei, Shuhe; Ma, Lena Q; Saha, Uttam; Mathews, Shiny; Sundaram, Sabarinath; Rathinasabapathi, Bala; Zhou, Qixing

2010-05-01

270

Bacteria-mediated arsenic oxidation and reduction in the growth media of arsenic hyperaccumulator Pteris vittata.  

PubMed

Microbes play an important role in arsenic transformation and cycling in the environment. Microbial arsenic oxidation and reduction were demonstrated in the growth media of arsenic hyperaccumulator Pteris vittata L. All arsenite (AsIII) at 0.1 mM in the media was oxidized after 48 h incubation. Oxidation was largely inhibited by antibiotics, indicating that bacteria played a dominant role. To identify AsIII oxidizing bacteria, degenerate primers were used to amplify ?500 bp of the AsIII oxidase gene aioA (aroA) using DNA extracted from the media. One aioA (aroA)-like sequence (MG-1, tentatively identified as Acinetobacter sp.) was amplified, exhibiting 82% and 91% identity in terms of gene and deduced protein sequence to those from Acinetobacter sp. 33. In addition, four bacterial strains with different arsenic tolerance were isolated and identified as Comamonas sp.C-1, Flavobacterium sp. C-2, Staphylococcus sp. C-3, and Pseudomonas sp. C-4 using carbon utilization, fatty acid profiles, and/or sequencing 16s rRNA gene. These isolates exhibited dual capacity for both AsV reduction and AsIII oxidation under ambient conditions. Arsenic-resistant bacteria with strong AsIII oxidizing ability may have potential to improve bioremediation of AsIII-contaminated water using P. vittata and/or other biochemical strategies. PMID:22994133

Wang, Xin; Rathinasabapathi, Bala; de Oliveira, Letuzia Maria; Guilherme, Luiz R G; Ma, Lena Q

2012-10-16

271

Characterization of arsenic-resistant bacteria from the rhizosphere of arsenic hyperaccumulator Pteris vittata.  

PubMed

Arsenic hyperaccumulator fern Pteris vittata L. produces large amounts of root exudates that are hypothesized to solubilize arsenic and maintain a unique rhizosphere microbial community. Total heterotrophic counts on rich or defined media supplemented with up to 400 mmol/L of arsenate showed a diverse arsenate-resistant microbial community from the rhizosphere of P. vittata growing in arsenic-contaminated sites. Twelve bacterial isolates tolerating 400 mmol/L of arsenate in liquid culture were identified. Selected bacterial isolates belonging to different genera were tested for their resistance to osmotic and oxidative stresses. Results showed that growth was generally better under osmotic stress generated by arsenic than under that generated by NaCl or PEG 6000, demonstrating that arsenic detoxification metabolism also cross-protected bacterial isolates from arsenic-induced osmotic stress. After 32 h of growth, all arsenate at 1 mmol/L was reduced to arsenite by strains Naxibacter sp. AH4, Mesorhizobium sp. AH5, and Pseudomonas sp. AH21, but arsenite at 1 mmol/L remained unchanged. Sensitivity to hydrogen peroxide was similar to that in broad-host pathogen Salmonella enterica sv. Typhimurium wild type, except strain AH4. The results suggested that these arsenic-resistant bacteria are metabolically adapted to arsenic-induced osmotic or oxidative stresses in addition to the specific bacterial system to exclude cellular arsenic. Both these adaptations contribute to the high arsenic resistance in the bacterial isolates. PMID:20453910

Huang, Anhui; Teplitski, Max; Rathinasabapathi, Bala; Ma, Lena

2010-03-01

272

Characterization of As efflux from the roots of As hyperaccumulator Pteris vittata L.  

PubMed

In some plant species, various arsenic (As) species have been reported to efflux from the roots. However, the details of As efflux by the As hyperaccumulator Pteris vittata remain unknown. In this study, root As efflux was investigated for different phosphorus (P) supply conditions during or after a 24-h arsenate uptake experiment under hydroponic growth conditions. During an 8-h arsenate uptake experiment, P-supplied (P+) P. vittata exhibited much greater arsenite efflux relative to arsenate uptake when compared with P-deprived (P-) P. vittata, indicating that arsenite efflux was not proportional to arsenate uptake. In the As efflux experiment following 24 h of arsenate uptake, arsenate efflux was also observed with arsenite efflux in the external solution. All the results showed relatively low rates of arsenate efflux, ranging from 5.4 to 16.1% of the previously absorbed As, indicating that a low rate of arsenate efflux to the external solution is also a characteristic of P. vittata, as was reported with arsenite efflux. In conclusion, after 24 h of arsenate uptake, both P+ and P- P. vittata loaded/effluxed similar amounts of arsenite to the fronds and the external solution, indicating a similar process of xylem loading and efflux for arsenite, with the order of the arsenite concentrations being solution ? roots ? fronds. PMID:21789508

Huang, Yi; Hatayama, Masayoshi; Inoue, Chihiro

2011-12-01

273

[Preliminary analysis of manganese uptake mechanism in the hyperaccumulator Phytolacca americana L].  

PubMed

Phytolacca americana L. (P. americana) is a manganese (Mn) hyperaccumulator plant discovered in southern China, and knowledge of Mn uptake characteristics and mechanisms on this plant may provide essential and critical information for phytoremediation. Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was empolyed in this study to explore the Mn distribution in the root cross-section of P. americana, and effects of metabolic inhibitors (DNP and Na3VO4) and Ca-channel inhibitor (LaCl3) on Mn uptake of P. americana was also investigated under laboratory conditions. Results showed that P. americana has strong abilities for absorpting and accumulating Mn, and the Mn concentration in root, stem, and leaf of P. americana may reach up to 402, 208, and 601 mg x kg(-1) DW, respectively, even only treated with 5 micromol x L(-1) Mn. The highest Mn content can be found in the vascular bundle of root, and then the epidermis, while the lowest Mn content can be observed in the cortex. The Mn content increased when shifted from cortex to vascular bundle, indicating that there was an active transportation in Mn absorption of P. americana root, and the inhibitory effect of DNP and Na3VO4 on Mn uptake further verified the possibilities of active absorption. The Mn uptake was inhibited by 30% with LaCl3, suggesting that Mn uptake in P. americana also closely related to the Ca-channel. PMID:24455960

Xu, Xiang-Hua; Li, Ren-Ying; Liu, Cui-Ying; Shi, Ji-Yan; Lin, Jia

2013-11-01

274

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

PubMed

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

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

275

Effects of Cu on the content of chlorophylls and secondary metabolites in the Cu-hyperaccumulator lichen Stereocaulon japonicum.  

PubMed

Understanding the relationship between Cu and Cu-hyperaccumulator lichens is important for their application in monitoring and assessing heavy metal pollution. We investigated the Cu-hyperaccumulator lichen Stereocaulon japonicum at several Cu-polluted and control sites in Japan, and found the lichen to be widely distributed. Its concentrations of Cu, chlorophylls, and secondary metabolites, chlorophyll-related indices, and absorption spectra were measured, and we observed negative effects of Cu on these concentrations and indices. For highly Cu-polluted samples (>100ppm dry weight), however, we found significant linear correlations between Cu and chlorophyll concentrations. This can be considered as the response of the photobiont in S. japonicum to Cu stress. In highly Cu-polluted samples the chlorophyll-related indices and concentration of total secondary metabolites were almost constant regardless of Cu concentration. This suggests that the increase in chlorophyll concentration with the increase in Cu concentration enhances photosynthetic productivity per unit biomass, which will allow the production of extra structure and energy for maintaining the chlorophyll-related indices under Cu stress. The relationship between the increase in chlorophyll concentration of S. japonicum and the decrease in secondary metabolite concentration of the lichen can be explained by considering the balance of carbohydrates in the lichen. We found that a spectral index A372-A394 can be a useful index of the concentrations of Cu and total secondary metabolites in S. japonicum. These findings show the adjustment of the content of chlorophylls and secondary metabolites in S. japonicum to Cu stress, and provide a better understanding of the relationship between Cu and the Cu-hyperaccumulator lichen. PMID:25562176

Nakajima, Hiromitsu; Hara, Kojiro; Yamamoto, Yoshikazu; Itoh, Kiminori

2015-03-01

276

Hyperaccumulator oilcake manure as an alternative for chelate-induced phytoremediation of heavy metals contaminated alluvial soils.  

PubMed

The ability of hyperaccumulator oilcake manure as compared to chelates was investigated by growing Calendula officinalis L for phytoremediation of cadmium and lead contaminated alluvial soil. The combinatorial treatment T6 [2.5 g kg(-1)oilcake manure + 5 mmol kg(-1) EDDS] caused maximum cadmium accumulation in root, shoot and flower up to 5.46, 4.74 and 1.37 mg kg(-1)and lead accumulation up to 16.11, 13.44 and 3.17 mg kg(-1), respectively at Naini dump site, Allahabad (S3). The treatment showed maximum remediation efficiency for Cd (RR = 0.676%) and Pb (RR = 0.202%) at Mumfordganj contaminated site (S2). However, the above parameters were also observed at par with the treatment T5 [2.5 g kg(-1)oilcake manure +2 g kg(-1) humic acid]. Applied EDDS altered chlorophyll-a, chlorophyll-b, and carotene contents of plants while application of oilcake manure enhanced their contents in plant by 3.73-8.65%, 5.81-17.65%, and 7.04-17.19%, respectively. The authors conclude that Calendula officinalis L has potential to be safely grown in moderately Cd and Pb-contaminated soils and application of hyperaccumulator oilcake manure boosts the photosynthetic pigments of the plant, leading to enhanced clean-up of the cadmium and lead-contaminated soils. Hence, the hyperaccumulator oilcake manure should be preferred over chelates for sustainable phytoremediation through soil-plant rhizospheric process. PMID:25397984

Mani, Dinesh; Kumar, Chitranjan; Patel, Niraj Kumar

2015-01-01

277

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

PubMed

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 CrVI0.10, and 5100 and 3500 mg/kg P in the fronds and roots at P0.25. 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, Cr2O3 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

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

2014-11-27

278

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

PubMed

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

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

2014-09-30

279

[Effects of manganese on antioxidant system of manganese-hyperaccumulator Phytolacca americana L.].  

PubMed

A hydroponic experiment was conducted to study the growth, manganese (Mn) accumulation, lipid peroxidation, H2O2 concentration, and antioxidant system of Phytolacca americana L. exposed to different concentration Mn. With increasing Mn concentration in the medium, the plant Mn content increased significantly, and the Mn accumulation was in the sequence of leaf > stem > root. Comparing with the control, low concentration (5 mmol x L(-1)) Mn promoted the plant growth, decreased the leaf H2O2 concentration, and had less effects on the leaf malondialdehyde (MDA) content, while high concentration (> or = 10 mmol x L(-1)) Mn led to a remarkable increase of leaf H2O2 and MDA contents, indicating an evident oxidative damage occurred in leaves. The activities of ascorbate peroxidase, dehydroascorbate reductase and glutathione reductase and the content of reduced ascorbate increased with increasing Mn concentration, while the SOD activity was inhibited significantly at 5 mmol x L(-1) of Mn but enhanced at > or = 10 mmol x L(-1) of Mn. The activities of catalase and peroxidase and the content of reduced glutathione increased at 5-10 mmol x L(-1) of Mn but dropped markedly at 20 mmol x L(-1) of Mn. All the results suggested that the Mn-induced oxidative damage and Mn accumulation might be responsible for the growth inhibition of P. americana plants at high Mn exposure, and the increase of antioxidative enzyme activities and low molecular antioxidant contents was, at least partly, contributed to the Mn tolerance and hyperaccumulation of P. americana. However, due to their different Mn concentration-dependent change modes, these antioxidants played different roles in the Mn tolerance of P. americana. PMID:20077708

Wang, Hai-Hua; Feng, Tao; Peng, Xi-Xu; Yan, Ming-Li; Tang, Xin-Ke

2009-10-01

280

Cd-induced changes in leaf proteome of the hyperaccumulator plant Phytolacca americana.  

PubMed

Cadmium (Cd) is highly toxic to all organisms. Soil contamination by Cd has become an increasing problem worldwide due to the intensive use of Cd-containing phosphate fertilizers and industrial zinc mining. Phytolacca americana L. is a Cd hyperaccumulator plant that can grow in Cd-polluted areas. However, the molecular basis for its remarkable Cd resistance is not known. In this study, the effects of Cd exposure on protein expression patterns in P.americana was investigated by 2-dimensional gel electrophoresis (2-DE). 2-DE profiles of leaf proteins from both control and Cd-treated (400?M, 48h) seedlings were compared quantitatively using ImageMaster software. In total, 32 differentially expressed protein spots were identified using MALDI-TOF/TOF mass spectrometry coupled to protein database search, corresponding to 25 unique gene products. Of those 14 were enhanced/induced while 11 reduced under Cd treatment. The alteration pattern of protein expression was verified for several key proteins involved in distinct metabolic pathways by immuno-blot analysis. Major changes were found for the proteins involved in photosynthetic pathways as well as in the sulfur- and GSH-related metabolisms. One-third of the up-regulated proteins were attributed to transcription, translation and molecular chaperones including a protein belonging to the calreticulin family. Other proteins include antioxidative enzymes such as 2-cys-peroxidase and oxidoreductases. The results of this proteomic analysis provide the first and primary information regarding the molecular basis of Cd hypertolerance in P. americana. PMID:21723586

Zhao, Le; Sun, Yong-Le; Cui, Su-Xia; Chen, Mei; Yang, Hao-Meng; Liu, Hui-Min; Chai, Tuan-Yao; Huang, Fang

2011-09-01

281

A Comparison of the Dietary Arsenic Exposures from Ingestion of Contaminated Soil and Hyperaccumulating Pteris Ferns Used in a Residential Phytoremediation Project  

Microsoft Academic Search

Arsenic (As) hyperaccumulating ferns are used to phytoremediate As-contaminated soils, including soils in residential areas. This use may pose a health risk if children were to ingest these plants. Spider brake (Pteris cretica L.) plants were grown in sand spiked with arsenate, to produce tissue As concentrations (2000–4500 mg kg DW) typical of those observed in plants deployed for As

Stephen Ebbs; Sarah Hatfield; Vinay Nagarajan; Michael Blaylock

2009-01-01

282

Interaction of cadmium and zinc on accumulation and sub-cellular distribution in leaves of hyperaccumulator Potentilla griffithii.  

PubMed

Potentilla griffithii Hook is a newly found hyperaccumulator plant capable of high tolerance and accumulation of Zn and Cd. We investigated the interactive effects between Cd and Zn on accumulation and vacuolar sequestration in P. griffithii. Stimulatory effect of growth was noted at 0.2 mM Cd and 1.25 and 2.5 mM Zn tested. Accumulation of Zn and Cd in roots, petioles and leaves were increased significantly with addition of these metals individually. However, the Zn supplement decreased root Cd accumulation but increased the concentration of Cd in petioles and leaves. The results from sub-cellular distribution showed that up to 94% and 70% of the total Zn and Cd in the leaves were present in the protoplasts, and more than 90% Cd and Zn in the protoplasts were localized in the vacuoles. Nearly, 88% and 85% of total Cd and Zn were extracted in the cell sap of the leaves suggesting that most of the Cd and Zn in the leaves were available in soluble form. The present results indicate that Zn supplement significantly enhanced the petiole accumulation of Cd and further vacuolar sequestration plays an important role in tolerance, detoxification and hyperaccumulation of these metals in P. griffithii. PMID:21211902

Qiu, Rong-Liang; Thangavel, Palaniswamy; Hu, Peng-Jie; Senthilkumar, Palaninaicker; Ying, Rong-Rong; Tang, Ye-Tao

2011-02-28

283

Hyperaccumulation of zinc by Noccaea caerulescens results in a cascade of stress responses and changes in the elemental profile.  

PubMed

Noccaea caerulescens (J. & C. Presl) F. K. Meyer is a metal hyperaccumulating plant which can accumulate more than 2% zinc (Zn) dry tissue mass in its aerial tissues. At this concentration Zn is toxic to most plants due to inhibition of enzyme function, oxidative damage and mineral deficiencies. In this study the elemental and metabolite profiles of N. caerulescens plants grown in four different Zn concentrations were measured. This revealed broad changes in the metabolite and elemental profiles with the hyperaccumulation of Zn. The Zn treated plants exhibited no typical signs of stress such as chlorosis or reduced biomass, however, a range of metabolic stress responses, such as the modification of galactolipids and the major membrane lipids of plastids, and increases in oxylipins, which are precursors to the signalling molecules jasmonic and abscisic acids, as well as the increased synthesis of glucosinolates, was observed. Increases in particular organic acids and the ubiquitous metal cation chelator nicotianamine were also observed. The small molecule metabolite changes observed, however, did not account for the extreme Zn concentrations in the leaf tissue showing that the increase in nicotianamine production most likely negates Fe deficiency. The elemental analyses also revealed significant changes in other essential micronutrients, in particular, significantly lower Mn concentrations in the high Zn accumulating plants, yet higher Fe concentrations. This comprehensive elemental and metabolite analysis revealed novel metabolite responses to Zn and offers evidence against organic acids as metal-storage ligands in N. caerulescens. PMID:24976134

Foroughi, Siavash; Baker, Alan J M; Roessner, Ute; Johnson, Alexander A T; Bacic, Antony; Callahan, Damien L

2014-09-01

284

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

PubMed Central

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

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

2013-01-01

285

Root and shoot transcriptome analysis of two ecotypes of Noccaea caerulescens uncovers the role of NcNramp1 in Cd hyperaccumulation.  

PubMed

The Zn/Cd hyperaccumulator, Noccaea caerulescens, has been studied extensively for its ability to accumulate high levels of Zn and Cd in its leaves. Previous studies have indicated that the Zn and Cd hyperaccumulation trait exhibited by this species involves different transport and tolerance mechanisms. It has also been well documented that certain ecotypes of N. caerulescens are much better Cd hyperaccumulators than others. However, there does not seem to be much ecotypic variation for Zn hyperaccumulation in N. caerulescens. In this study we employed a comparative transcriptomics approach to look at root and shoot gene expression in Ganges and Prayon plants in response to Cd stress to identify transporter genes that were more highly expressed in either the roots or shoots of the superior Cd accumulator, Ganges. Comparison of the transcriptomes from the two ecotypes of Noccaea caerulescens identified a number of genes that encoded metal transporters that were more highly expressed in the Ganges ecotype in response to Cd stress. Characterization of one of these transporters, NcNramp1, showed that it is involved in the influx of Cd across the endodermal plasma membrane and thus may play a key role in Cd flux into the stele and root-to-shoot Cd transport. NcNramp1 may be one of the main transporters involved in Cd hyperaccumulation in N. caerulescens and copy number variation appears to be the main reason for high NcNramp1 gene expression underlying the increased Cd accumulation in the Ganges ecotype. PMID:24547775

Milner, Matthew J; Mitani-Ueno, Namiki; Yamaji, Naoki; Yokosho, Kengo; Craft, Eric; Fei, Zhangjun; Ebbs, Stephen; Clemencia Zambrano, M; Ma, Jian Feng; Kochian, Leon V

2014-05-01

286

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

PubMed

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 became unavailable for loading into the xylem and subsequent translocation to shoot. Long-term efflux of absorbed 65Zn indicated that 65Zn activity was 6.8-fold higher in shoots but 3.7-fold lower in roots of the HE. At lower Zn levels (10 and 100 microM), there were no significant differences in 65Zn uptake by leaf sections and intact leaf protoplasts between the two ecotypes except that 1.5-fold more 65Zn was accumulated in leaf sections of the HE than in those of the NHE after exposure to 100 microM for 48 h. At 1,000 microM Zn, however, approximately 2.1-fold more Zn was taken up by the HE leaf sections and 1.5-fold more 65Zn taken up by the HE protoplasts as compared to the NHE at exposure times >16 h and >10 min, respectively. Treatments with carbonyl cyanide m-chlorophenylhydrazone (CCCP) or ruptured protoplasts strongly inhibited 65Zn uptake into leaf protoplasts for both ecotypes. Citric acid and Val concentrations in leaves and stems significantly increased for the HE, but decreased or had minimal changes for the NHE in response to raised Zn levels. These results indicate that altered Zn transport across tonoplast in the root and stimulated Zn uptake in the leaf cells are the major mechanisms involved in the strong Zn hyperaccumulation observed in S. alfredii H. PMID:16362325

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

2006-06-01

287

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

PubMed Central

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

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

2009-01-01

288

Engineering arsenic tolerance and hyperaccumulation in plants for phytoremediation by a PvACR3 transgenic approach.  

PubMed

Arsenic (As) pollution is a global problem, and the plant-based cleanup of contaminated soils, called phytoremediation, is therefore of great interest. Recently, transgenic approaches have been designed to develop As phytoremediation technologies. Here, we used a one-gene transgenic approach for As tolerance and accumulation in Arabidopsis thaliana . PvACR3, a key arsenite [As(III)] antiporter in the As hyperaccumulator fern Pteris vittata , was expressed in Arabidopsis , driven by the CaMV 35S promoter. In response to As treatment, PvACR3 transgenic plants showed greatly enhanced tolerance. PvACR3 transgenic seeds could even germinate and grow in the presence of 80 ?M As(III) or 1200 ?M arsenate [As(V)] treatments that were lethal to wild-type seeds. PvACR3 localizes to the plasma membrane in Arabidopsis and increases arsenite efflux into external medium in short-term experiments. Arsenic determination showed that PvACR3 substantially reduced As concentrations in roots and simultaneously increased shoot As under 150 ?M As(V). When cultivated in As(V)-containing soil (10 ppm As), transgenic plants accumulated approximately 7.5-fold more As in above-ground tissues than wild-type plants. This study provides important insights into the behavior of PvACR3 and the physiology of As metabolism in plants. Our work also provides a simple and practical PvACR3 transgenic approach for engineering As-tolerant and -hyperaccumulating plants for phytoremediation. PMID:23899224

Chen, Yanshan; Xu, Wenzhong; Shen, Hongling; Yan, Huili; Xu, Wenxiu; He, Zhenyan; Ma, Mi

2013-08-20

289

Hyperaccumulator of Pb in native plants growing on Peruvian mine tailings  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

290

Speciation and localization of Zn in the hyperaccumulator Sedum alfredii by extended X-ray absorption fine structure and micro-X-ray fluorescence.  

PubMed

Differences in metal homeostasis among related plant species can give important information of metal hyperaccumulation mechanisms. Speciation and distribution of Zn were investigated in a hyperaccumulating population of Sedum alfredii by using extended X-ray absorption fine structure and micro-synchrotron X-ray fluorescence (?-XRF), respectively. The hyperaccumulator uses complexation with oxygen donor ligands for Zn storage in leaves and stems, and variations in the Zn speciation was noted in different tissues. The dominant chemical form of Zn in leaves was most probably a complex with malate, the most prevalent organic acid in S. alfredii leaves. In stems, Zn was mainly associated with malate and cell walls, while Zn-citrate and Zn-cell wall complexes dominated in the roots. Two-dimensional ?-XRF images revealed age-dependent differences in Zn localization in S. alfredii stems and leaves. In old leaves of S. alfredii, Zn was high in the midrib, margin regions and the petiole, whereas distribution of Zn was essentially uniform in young leaves. Zinc was preferentially sequestered by cells near vascular bundles in young stems, but was highly localized to vascular bundles and the outer cortex layer of old stems. The results suggest that tissue- and age-dependent variations of Zn speciation and distribution occurred in the hyperaccumulator S. alfredii, with most of the Zn complexed with malate in the leaves, but a shift to cell wall- and citric acid-Zn complexes during transportation and storage in stems and roots. This implies that biotransformation in Zn complexation occurred during transportation and storage processes in the plants of S. alfredii. PMID:25306525

Lu, Lingli; Liao, Xingcheng; Labavitch, John; Yang, Xiaoe; Nelson, Erik; Du, Yonghua; Brown, Patrick H; Tian, Shengke

2014-11-01

291

Elemental distribution in reproductive and neural organs of the Epilachna nylanderi (Coleoptera: Coccinellidae), a phytophage of nickel hyperaccumulator Berkheya coddii (Asterales: Asteraceae) by micro-PIXE.  

PubMed

The phenomenon of metal hyperaccumulation by plants is often explained by a pathogen or herbivore defense hypothesis. However, some insects feeding on metal hyperaccumulating plants are adapted to the high level of metals in plant tissues. Former studies on species that feed on the leaves of Berkheya coddii Roessler 1958 (Asteraceae), a nickel-hyperaccumulating plant, demonstrated several protective mechanisms involved in internal distribution, immobilization, and elimination of Ni from the midgut and Malpighian tubules. These species are mainly coleopterans, including the lady beetle, Epilachna nylanderi (Mulsant 1850) (Coleoptera: Coccinellidae), collected from the ultramafic ecosystem near Barberton in South Africa. By performing particle-induced X-ray emission microanalysis elemental microanalysis (PIXE), this study examined whether Ni may be harmful to internal body systems that decide on insect reactivity (central nervous system [CNS]), their reproduction, and the relationships between Ni and other micronutrients. Data on elemental distribution of nine selected elements in target organs of E. nylanderi were compared with the existing data for other insect species adapted to the excess of metals. Micro-PIXE maps of seven regions of the CNS showed Ni mainly in the neural connectives, while cerebral ganglia were better protected. Concentrations of other bivalent metals were lower than those of Ni. Testis, compared with other reproductive organs, showed low amounts of Ni. Zn was effectively regulated at physiological dietary levels. In insects exposed to excess dietary Zn, it was also accumulated in the reproductive organs. Comparison of E. nylanderii with other insects that ingest hyperaccumulating plants, especially chrysomelid Chrysolina clathrata (Clark) (Coleoptera: Chrysomelidae), showed lower protection of the CNS and reproductive organs. PMID:25399425

Mesjasz-Przyby?owicz, Jolanta; Or?owska, El?bieta; Augustyniak, Maria; Nakonieczny, Miros?aw; Tarnawska, Monika; Przyby?owicz, Wojciech; Migula, Pawe?

2014-01-01

292

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

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

Khaokaew, Saengdao; Landrot, Gautier

2014-11-01

293

Quantitative elemental localisation in leaves and stems of nickel hyperaccumulating shrub Hybanthusfloribundus subsp. floribundus using micro-PIXE spectroscopy  

NASA Astrophysics Data System (ADS)

Hybanthusfloribundus (Lindl.) F.Muell. subsp. floribundus is a native Australian nickel (Ni) hyperaccumulating shrub and a promising species for rehabilitation and phytoremediation of Ni tailings. Spatial localisation and quantification of Ni in leaf and stem tissues of H.floribundus subsp. floribundus was studied using micro-proton-induced X-ray emission (micro-PIXE) spectroscopy. Young plants, grown in a potting mix under controlled glasshouse conditions were exposed to Ni concentrations of 0 and 26 mM kg -1 for 20 weeks. Leaf and stem samples were hand-sectioned and freeze-dried prior to micro-PIXE analysis. Elemental distribution maps of leaves revealed Ni concentration of 7800 mg kg -1 dry weight (DW) in whole leaf sections, which was identical to the bulk tissue analysis. Elemental maps showed that Ni was preferentially localised in the adaxial epidermis (10,000 mg kg -1 DW) and reached a maximum of up to 10,000 mg kg -1 DW in the leaf margin. Freeze-dried stem sections from the same plants contained lower Ni than leaf tissues (1800 mg kg -1 versus 7800 mg kg -1 DW, respectively), however did not resolve a clear pattern of compartmentalisation across different anatomical regions. Our results suggest localisation in epidermal cells is an important physiological mechanism involved in Ni accumulation and tolerance in leaves of H.floribundus subsp. floribundus.

Kachenko, Anthony G.; Singh, Balwant; Bhatia, Naveen P.; Siegele, Rainer

2008-02-01

294

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

PubMed

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 (micro-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. PMID:19954803

McNear, David H; Chaney, Rufus L; Sparks, Donald L

2010-02-01

295

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

PubMed

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

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

2014-01-01

296

Arsenic-resistant bacteria solubilized arsenic in the growth media and increased growth of arsenic hyperaccumulator Pteris vittata L.  

PubMed

The role of arsenic-resistant bacteria (ARB) in arsenic solubilization from growth media and growth enhancement of arsenic-hyperaccumulator Pteris vittata L. was examined. Seven ARB (tolerant to 10 mM arsenate) were isolated from the P. vittata rhizosphere and identified by 16S rRNA sequencing as Pseudomonas sp., Comamonas sp. and Stenotrophomonas sp. During 7-d hydroponic experiments, these bacteria effectively solubilized arsenic from the growth media spiked with insoluble FeAsO? and AlAsO? minerals (from < 5 ?g L?¹ to 5.04-7.37 mg L?¹ As) and enhanced plant arsenic uptake (from 18.1-21.9 to 35.3-236 mg kg?¹ As in the fronds). Production of (1) pyochelin-type siderophores by ARB (fluorescent under ultraviolet illumination and characterized with thin layer chromatography) and (2) root exudate (dissolved organic C) by P. vittata may be responsible for As solubilization. Increase in P. vittata root biomass from 1.5-2.2 to 3.4-4.2 g/plant dw by ARB and by arsenic was associated with arsenic-induced plant P uptake. Arsenic resistant bacteria may have potential to enhance phytoremediation of arsenic-contaminated soils by P. vittata. PMID:21840210

Ghosh, Piyasa; Rathinasabapathi, Bala; Ma, Lena Q

2011-10-01

297

A vacuolar arsenite transporter necessary for arsenic tolerance in the arsenic hyperaccumulating fern Pteris vittata is missing in flowering plants.  

PubMed

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

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

2010-06-01

298

Selection and Validation of Reference Genes for Real-Time Quantitative PCR in Hyperaccumulating Ecotype of Sedum alfredii under Different Heavy Metals Stresses  

PubMed Central

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

Liu, Mingying; Qiao, Guirong; Jiang, Jing; Zhuo, Renying

2013-01-01

299

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

PubMed

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

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

2015-03-01

300

Mixed arbuscular mycorrhizal (AM) fungal application to improve growth and arsenic accumulation of Pteris vittata (As hyperaccumulator) grown in As-contaminated soil.  

PubMed

A greenhouse pot experiment was conducted to study the effects of three types of single inoculum [indigenous mycorrhizas (IM) isolated from As mine, Glomus mosseae (GM) and Glomus intraradices (GI)] and two types of mixed inoculum (mixed with IM and either GM or GI) on the growth response of Pteris vittata (hyperaccumulator) and Cynodon dactylon (non-hyperaccumulator) at three levels of As concentrations (0, 100 and 200mgkg(-1)). Both mycorrhizal plants exhibited significantly higher biomass, and N and P accumulation in its tissue than the control. Among the mycorrhizal inoculum, the mixed inoculum IM/GM promoted substantially higher mycorrhizal colonization and arsenate reductase activity in P. vittata than C. dactylon, among all As levels. The portion of Paris arbuscular mycorrhizal structure (observed in colonized roots) together with the highest As translocation factor of 10.2 in P. vittata inoculated with IM/GM was also noted. It was deduced that IM/GM inoculum may be the best choice for field inoculation at any contaminated lands as the inoculum exhibited better adaptation to variable environmental conditions and hence benefited the host plants. PMID:23755987

Leung, H M; Leung, A O W; Ye, Z H; Cheung, K C; Yung, K K L

2013-08-01

301

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

SciTech Connect

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.

Kochian, L.

1997-11-01

302

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

SciTech Connect

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.

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

1995-12-01

303

A comparison of the dietary arsenic exposures from ingestion of contaminated soil and hyperaccumulating Pteris ferns used in a residential phytoremediation project.  

PubMed

Arsenic (As) hyperaccumulating ferns are used to phytoremediate As-contaminated soils, including soils in residential areas. This use may pose a health risk if children were to ingest these plants. Spider brake (Pteris cretica L.) plants were grown in sand spiked with arsenate, to produce tissue As concentrations (2000-4500 mg kg DW(-1)) typical of those observed in plants deployed for As phytoremediation. The fronds were subjected to a physiologically-based extraction test to estimate As bioaccessibility, which ranged from 3.4-20.5%. A scenario for human dietary exposure to As in an urban setting was then estimated for a child consuming 0.25 g DW of tissue. The calculation of dietary exposure took into account the As concentration in the fern pinnae, the bioaccessibility of As in the tissue, and the typical absorption of inorganic As by the gastrointestinal tract. The pinnae As concentrations and the calculated dietary exposures were used to create a non-linear regression model relating tissue As concentration to dietary exposure. Data from a phytoremediation project in a residential area using Pteris cretica and Pteris vittata (L.) were input into this model to project dietary As exposure in a residential phytoremediation setting. These exposures were compared to estimates of dietary As exposure from the consumption of soil. The results showed that dietary exposures to As from consumption of soil or pinnae tissue were similar and that estimates of dietary exposure were below the LOAEL value of 14 microg As kg(-1) d(-1). The results suggest that the hyperaccumulation of As in Pteris ferns during growth in moderately contaminated residential soils (e.g., < or = 100 mg As kg DW(-1)) does not represent an inherent risk or a risk substantially different from that posed by accidental ingestion of contaminated soil. PMID:20734633

Ebbs, Stephen; Hatfield, Sarah; Nagarajan, Vinay; Blaylock, Michael

2010-01-01

304

LC–MS and GC–MS metabolite profiling of nickel(II) complexes in the latex of the nickel-hyperaccumulating tree Sebertia acuminata and identification of methylated aldaric acid as a new nickel(II) ligand  

Microsoft Academic Search

Targeted liquid chromatography–mass spectrometry (LC–MS) technology using size exclusion chromatography and metabolite profiling based on gas chromatography–mass spectrometry (GC–MS) were used to study the nickel-rich latex of the hyperaccumulating tree Sebertia acuminata. More than 120 compounds were detected, 57 of these were subsequently identified. A methylated aldaric acid (2,4,5-trihydroxy-3-methoxy-1,6-hexan-dioic acid) was identified for the first time in biological extracts and

Damien L. Callahan; Ute Roessner; Vincent Dumontet; Nicolas Perrier; Anthony G. Wedd; Richard A. J. O’Hair; Alan J. M. Baker; Spas D. Kolev

2008-01-01

305

Phytoremediation and hyperaccumulator plants  

Microsoft Academic Search

Phytoremediation is a group of technologies that use plants to reduce, remove, degrade, or immobilize environmental toxins,\\u000a primarily those of anthropogenic origin, with the aim of restoring area sites to a condition useable for private or public\\u000a applications. Phytoremediation efforts have largely focused on the use of plants to accelerate degradation of organic contaminants,\\u000a usually in concert with root rhizosphere

Wendy Ann Peer; Ivan R. Baxter; Elizabeth L. Richards; John L. Freeman; Angus Murphy

306

Effect of CO, NOx and SO2 on ROS production, photosynthesis and ascorbate–glutathione pathway to induce Fragaria×annasa as a hyperaccumulator?  

PubMed Central

A study was conducted to determine the effect of carbon monoxide (CO), nitroxide (NOx) and sulfur dioxide (SO2) on ROS production, photosynthesis and ascorbate–glutathione pathway in strawberry plants. The results showed that both singlet oxygen (O2?1) and hydrogen peroxide (H2O2) content increased in CO, NOx and SO2 treated strawberry leaves. A drastic reduction of primary metabolism of plants (photosynthesis), with the closure of stomata, resulted in a reduction of protein, carbohydrate and sucrose content due to production of reactive oxygen species (ROS) under prolonged exposure of gas stress. The resulting antioxidant enzymes were increased under a low dose of gas stress, whereas they were decreased due to a high dose of gas stress. Our results indicate that increased ROS may act as a signal to induce defense responses to CO, NOx and SO2 gas stress. The increased level of antioxidant enzymes plays a significant role in plant protection due to which strawberry plants can be used as a hyperaccumulator to maintain environmental pollution, however, the defense capacity cannot sufficiently alleviate oxidative damage under prolonged exposure of CO, NOx and SO2 stress. PMID:25460723

Muneer, Sowbiya; Kim, Tae Hwan; Choi, Byung Chul; Lee, Beom Seon; Lee, Jeong Hyun

2013-01-01

307

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

PubMed Central

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

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

2010-01-01

308

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

PubMed

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

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

2013-01-01

309

Effect of metal stress on photosynthetic pigments in the Cu-hyperaccumulating lichens Cladonia humilis and Stereocaulon japonicum growing in Cu-polluted sites in Japan.  

PubMed

To understand the ecology and physiology of metal-accumulating lichens growing in Cu-polluted sites, we investigated lichens near temple and shrine buildings with Cu roofs in Japan and found that Stereocaulon japonicum Th. Fr. and Cladonia humilis (With.) J. R. Laundon grow in Cu-polluted sites. Metal concentrations in the lichen samples collected at some of these sites were determined by inductively coupled plasma mass spectroscopy (ICP-MS). UV-vis absorption spectra of pigments extracted from the lichen samples were measured, and the pigment concentrations were estimated from the spectral data using equations from the literature. Secondary metabolites extracted from the lichen samples were analyzed by high-performance liquid chromatography (HPLC) with a photodiode array detector. We found that S. japonicum and C. humilis are Cu-hyperaccumulating lichens. Differences in pigment concentrations and their absorption spectra were observed between the Cu-polluted and control samples of the 2 lichens. However, no correlation was found between Cu and pigment concentrations. We observed a positive correlation between Al and Fe concentrations and unexpectedly found high negative correlations between Al and pigment concentrations. This suggests that Al stress reduces pigment concentrations. The concentrations of secondary metabolites in C. humilis growing in the Cu-polluted sites agreed with those in C. humilis growing in the control sites. This indicates that the metabolite concentrations are independent of Cu stress. PMID:23953993

Nakajima, Hiromitsu; Yamamoto, Yoshikazu; Yoshitani, Azusa; Itoh, Kiminori

2013-11-01

310

Arsenic accumulation pattern in 12 Indian ferns and assessing the potential of Adiantum capillus-veneris, in comparison to Pteris vittata, as arsenic hyperaccumulator.  

PubMed

The present study was undertaken to evaluate the ability of some Indian ferns to accumulate and tolerate arsenic. Twelve species of Indian ferns were exposed to 10 mg L(-1) arsenic as sodium arsenate for 15 days in hydroponic system. Depending on the arsenic uptake in the plant parts--Pteris vittata, Pteris cretica, Adiantum capillus-veneris and Nephrolepis exaltata may be categorised as arsenic accumulator. Further, A. capillus-veneris plants were grown in arsenic contaminated soil (200-600 mg kg(-1)) under green-house condition, to assess its arsenic accumulation and tolerance mechanism, in comparison to known As-hyperaccumulator--P. vittata Linn., growing in the same conditions. The experiment identified A. capillus-veneris having a potential to tolerate arsenic up to 500 mg kg(-1). The plants were analysed for the extent of oxidative stress, as a result of arsenic accumulation. A. capillus-veneris was able to detoxify the arsenic stress through induction of anti-oxidant defence system. PMID:20655204

Singh, Nandita; Raj, Anshita; Khare, P B; Tripathi, R D; Jamil, Sarah

2010-12-01

311

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

PubMed

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

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

312

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

PubMed Central

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

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

2010-01-01

313

A comparison of arsenic tolerance, uptake and accumulation between arsenic hyperaccumulator, Pteris vittata L. and non-accumulator, P. semipinnata L.--a hydroponic study.  

PubMed

The differences in arsenic (As) tolerance, uptake and accumulation between Pteris vittata (an As hyperaccumulator) and P. semipinnata (nonaccumulator) were investigated under hydroponic conditions. The results showed that As uptake by P. vittata was significantly higher (p<0.05) than that of P. semipinnata. Significantly higher concentrations of As accumulated in the fronds of P. vittata, while in the roots of P. semipinnata. The short-term (<24h) uptake kinetics were fitted a hyperbolic equation which could be divided into linear and saturable components (described by Michaelis-Menten kinetics/model). The increase in hydrogen peroxide (H(2)O(2)) content in both plant species significantly correlated (p<0.05) with increasing As content in the plants and As exposure time, especially for midrib of P. semipinnata. P. semipinnata showed higher concentrations of H(2)O(2) than those of P. vittata. The relative electrical conductivity (REC, %) values in the root and pinnae followed a similar trend as plant H(2)O(2) contents, increasing with As exposure, especially for P. semipinnata. Significantly higher REC (%) values (p<0.05) were observed in the root than that in pinnae of P. semipinnata. The results indicated that high doses of As produced oxidative damages in both plant species. PMID:19577839

Lou, L Q; Ye, Z H; Wong, M H

2009-11-15

314

Fractionation of stable zinc isotopes in the field-grown zinc hyperaccumulator Noccaea caerulescens and the zinc-tolerant plant Silene vulgaris.  

PubMed

Stable Zn isotope signatures offer a potential tool for tracing Zn uptake and transfer mechanisms within plant-soil systems. Zinc isotopic compositions were determined in the Zn hyperaccumulator Noccaea caerulescens collected at a Zn-contaminated site (Viviez), a serpentine site (Vosges), and a noncontaminated site (Sainte Eulalie) in France. Meanwhile, a Zn-tolerant plant ( Silene vulgaris ) was also collected at Viviez for comparison. While ?(66)Zn was substantially differentiated among N. caerulescens from the three localities, they all exhibited an enrichment in heavy Zn isotopes of 0.40-0.72‰ from soil to root, followed by a depletion in heavy Zn from root to shoot (-0.10 to -0.50‰). The enrichment of heavy Zn in roots is ascribed to the transport systems responsible for Zn absorption into root symplast and root-to-shoot translocation, while the depletion in heavy Zn in shoots is likely to be mediated by a diffusive process and an efficient translocation driven by energy-required transporters (e.g., NcHMA4). The mass balance yielded a bulk Zn isotopic composition between plant and soil (?(66)Zn(plant-soil)) of -0.01‰ to 0.63‰ in N. caerulescens , indicative of high- and/or low-affinity transport systems operating in the three ecotypes. In S. vulgaris , however, there was no significant isotope fractionation between whole plant and rhizosphere soil and between root and shoot, suggesting that this species appears to have a particular Zn homeostasis. We confirm that quantifying stable Zn isotopes is useful for understanding Zn accumulation mechanisms in plants. PMID:22891730

Tang, Ye-Tao; Cloquet, Christophe; Sterckeman, Thibault; Echevarria, Guillaume; Carignan, Jean; Qiu, Rong-Liang; Morel, Jean-Louis

2012-09-18

315

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

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

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

2008-09-29

316

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

PubMed Central

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

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

2014-01-01

317

Identification of target genes of the bZIP transcription factor OsTGAP1, whose overexpression causes elicitor-induced hyperaccumulation of diterpenoid phytoalexins in rice cells.  

PubMed

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

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

2014-01-01

318

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

PubMed Central

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

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

2011-01-01

319

Expression of HMA4 cDNAs of the zinc hyperaccumulator Noccaea caerulescens from endogenous NcHMA4 promoters does not complement the zinc-deficiency phenotype of the Arabidopsis thaliana hma2hma4 double mutant  

PubMed Central

Noccaea caerulescens (Nc) exhibits a very high constitutive expression of the heavy metal transporting ATPase, HMA4, as compared to the non-hyperaccumulator Arabidopsis thaliana (At), due to copy number expansion and altered cis-regulation. We screened a BAC library for HMA4 and found that HMA4 is triplicated in the genome of a N. caerulescens accession from a former Zn mine near La Calamine (LC), Belgium. We amplified multiple HMA4 promoter sequences from three calamine N. caerulescens accessions, and expressed AtHMA4 and different NcHMA4 cDNAs under At and Nc HMA4 promoters in the A. thaliana (Col) hma2hma4 double mutant. Transgenic lines expressing HMA4 under the At promoter were always fully complemented for root-to-shoot Zn translocation and developed normally at a 2-?M Zn supply, whereas the lines expressing HMA4 under Nc promoters usually showed only slightly enhanced root to shoot Zn translocation rates in comparison with the double mutant, probably owing to ectopic expression in the roots, respectively. When expression of the Zn deficiency responsive marker gene ZIP4 was tested, the transgenic lines expressing AtHMA4 under an NcHMA4-1-LC promoter showed on average a 7-fold higher expression in the leaves, in comparison with the double hma2hma4 mutant, showing that this construct aggravated, rather than alleviated the severity of foliar Zn deficiency in the mutant, possible owing to expression in the leaf mesophyll. PMID:24187545

Iqbal, Mazhar; Nawaz, Ismat; Hassan, Zeshan; Hakvoort, Henk W. J.; Bliek, Mattijs; Aarts, Mark G.M.; Schat, Henk

2013-01-01

320

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

SciTech Connect

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.

Kochian, L.

1995-12-31

321

Genetic and Molecular Dissection of Arsenic Hyperaccumulation  

SciTech Connect

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.

Banks, Jo Ann

2005-06-01

322

Accumulation and hyperaccumulation of copper in plants  

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

323

Thlaspi arvense (Pennycress) as a biodiesel in a one year-two crop rotation with soybean  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increased demand for energy has generated renewed interest in the development of oilseed crops. The short term answer to biodiesel has always been soybean. Unfortunately, soybean oil has several shortcomings in its effort to supply the U.S. market. First, and foremost, is the fact that if all curr...

324

Interactions between plant and rhizosphere microbial communities in a metalliferous soil.  

PubMed

In the present work, the relationships between plant consortia, consisting of 1-4 metallicolous pseudometallophytes with different metal-tolerance strategies (Thlaspi caerulescens: hyperaccumulator; Jasione montana: accumulator; Rumex acetosa: indicator; Festuca rubra: excluder), and their rhizosphere microbial communities were studied in a mine soil polluted with high levels of Cd, Pb and Zn. Physiological response and phytoremediation potential of the studied pseudometallophytes were also investigated. The studied metallicolous populations are tolerant to metal pollution and offer potential for the development of phytoextraction and phytostabilization technologies. T. caerulescens appears very tolerant to metal stress and most suitable for metal phytoextraction; the other three species enhance soil functionality. Soil microbial properties had a stronger effect on plant biomass rather than the other way around (35.2% versus 14.9%). An ecological understanding of how contaminants, ecosystem functions and biological communities interact in the long-term is needed for proper management of these fragile metalliferous ecosystems. PMID:20036453

Epelde, Lur; Becerril, José M; Barrutia, Oihana; González-Oreja, José A; Garbisu, Carlos

2010-05-01

325

Arsenic hyperaccumulation by brake ferns and their potential in phytoremediation  

Microsoft Academic Search

Municipal solid waste incinerator (MSWI) fly ash is world-widely defined as hazardous waste because of its high concentration of heavy metals and high toxic equivalents of dioxin-like compounds. Therefore, if not properly disposed, it would pose a risk of being released into the environment including soil and groundwater. Heavy metals in the MSWI fly ash are considered as the most

Chaoyang Wei; Feng LIU; Peng ZHENC; Yongfeng NIE

2006-01-01

326

Screening of Amaranth Cultivars ( Amaranthus mangostanus L.) for Cadmium Hyperaccumulation  

Microsoft Academic Search

The potential harm of soil cadmium pollution to ecological environment and human health has been increasingly widely concerned. Phytoremediation, as a kind of new and effective technology, has become an important method for cleaning up cadmium in contaminated sites. The amaranth (Amaranthus mangostanus L.) is widely distributed and has abundant varieties in China, its rapid growth and large biomass can

Hong-li FAN; Wei ZHOU

2009-01-01

327

RESEARCH ARTICLE Open Access Selenium hyperaccumulation offers protection  

E-print Network

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 plants containing up to 200 mg Se kg-1 dry weight, concentrations which are toxic to many other

328

XAS Speciation of Arsenic in a Hyper-Accumulating Fern  

E-print Network

high As concentrations (ca. 1% As per dry weight) arsenic in the fern leaves is coordinated accumulated as As(III) in the leaves. XANES and EXAFS results show that As(III) in the leaves is primarily to be an extremely effective hyperac- cumulator of arsenic (25). The fern leaves accumulate arsenic

Ma, Lena

329

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

PubMed

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

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

2010-09-15

330

Thermal treatment of metal-enriched biomass produced from heavy metal phytoextraction.  

PubMed

Phytoextraction is an environmentally sound method for cleaning up sites that are contaminated with toxic heavy metals. However, the method has been questioned because it produces a biomass-rich secondary waste containing the extracted metals. Therefore, further treatment of this biomass is necessary. In this study, we investigated whether thermal treatment could be a feasible option for evaporatively separating metals from the plant residues. We used a laboratory scale reactor designed to simulate the volatilization behavior of heavy metals in a grate furnace. The evaporation of alkali and heavy metals from plant samples was investigated online, using a thermo-desorption spectrometer (TDS). Experiments were performed in the temperature range of 25-950 degrees C with leaves of the Cd and Zn hyperaccumulator Thlaspi caerulescens and of the high biomass plant Salix viminalis (willow), both grown on contaminated soils. Gasification (i.e., pyrolysis), which occurs under reducing conditions, was a better method than incineration under oxidizing conditions to increase volatilization and, hence subsequently recovery, of Cd and Zn from plants. It would also allow the recycling of the bottom ash as fertilizer. Thus, our investigations confirmed that incineration (or co-incineration) is a viable option for the treatment of the heavy metal-enriched plants. PMID:15926590

Keller, Catherine; Ludwig, Christian; Davoli, Frédéric; Wochele, Jörg

2005-05-01

331

Generation of nonvernal-obligate, faster-cycling Noccaea caerulescens lines through fast neutron mutagenesis.  

PubMed

Noccaea caerulescens (formerly Thlaspi caerulescens) is a widely studied metal hyperaccumulator. However, molecular genetic studies are challenging in this species because of its vernal-obligate biennial life cycle of 7-9months. Here, we describe the development of genetically stable, faster cycling lines of N. caerulescens which are nonvernal-obligate. A total of 5500 M(0) seeds from Saint Laurent Le Minier (France) were subjected to fast neutron mutagenesis. Following vernalization of young plants, 79% of plants survived to maturity. In all, 80,000 M(2) lines were screened for flowering in the absence of vernalization. Floral initials were observed in 35 lines, with nine flowering in <12wk. Two lines (A2 and A7) were selfed to the M(4) generation. Floral initials were observed 66 and 87d after sowing (DAS) in A2 and A7, respectively. Silicle development occurred for all A2 and for most A7 at 92 and 123 DAS, respectively. Floral or silicle development was not observed in wild-type (WT) plants. Leaf zinc (Zn) concentration was similar in WT, A2 and A7 lines. These lines should facilitate future genetic studies of this remarkable species. Seed is publicly available through the European Arabidopsis Stock Centre (NASC). PMID:21058953

Lochlainn, Seosamh O; Fray, Rupert G; Hammond, John P; King, Graham J; White, Philip J; Young, Scott D; Broadley, Martin R

2011-01-01

332

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

PubMed

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

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

2012-06-01

333

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

PubMed

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

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

2005-01-01

334

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

Microsoft Academic Search

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,

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

335

MELANOTRICHUS BOYDI (HEMIPTERA: MIRIDAE) IS A SPECIALIST ON THE NICKEL HYPERACCUMULATOR STREPTANTHUS  

E-print Network

with the polyphagous mirid Lygus hesperus (both collected from S. polygaloides) showed M. boydi preferred S hospedero contrastando M. boydi con la chinche ligus Lygus hesperus (ambos colectados en S. polygaloides

Boyd, Robert S.

336

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...

337

Three new arsenic hyperaccumulating ferns Mrittunjai Srivastava, Lena Q. Ma , Jorge Antonio Gonzaga Santos  

E-print Network

., 1998; Nriagu, 2002). Arsenic contamination affects biological activi- ties as a teratogen, carcinogen and mutagen as well as having detrimental effects on the immune system (Squibb and Fowler, 1983). The evidence- pensive form of ecological engineering that has proven effective in some cases (Raskin et al., 1994

Ma, Lena

338

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

PubMed

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

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

2015-03-01

339

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

USGS Publications Warehouse

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.

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

2011-01-01

340

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

USGS Publications Warehouse

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.

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

2011-01-01

341

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

PubMed Central

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

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

2012-01-01

342

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

Microsoft Academic Search

\\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

Bala Rathinasabapathi

343

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

344

Effects of Plant Age on Arsenic Hyperaccumulation by Pteris vittata L.  

E-print Network

demonstrated that the use of young plants can be an effective strategy to reduce the time to remediate an As.1 times compared to the initial frond biomass, from youngest to oldest, respec- tively. Higher phosphorus age. It is known that during the sigmoidal phase of a plant growth cycle, dry matter and nutrient

Ma, Lena

345

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

E-print Network

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

Ma, Lena

346

Accumulation and tolerance characteristics of cadmium in a halophytic Cd-hyperaccumulator, Arthrocnemum macrostachyum  

Microsoft Academic Search

The potential of the extreme halophyte Arthrocnemum macrostachyum was examined to determine its tolerance and ability to accumulate cadmium for phytoremediation purposes. A glasshouse experiment was designed to investigate the effect of cadmium from 0 to 1.35mmoll?1 on the growth and the photosynthetic apparatus of A. macrostachyum by measuring chlorophyll fluorescence parameters, gas exchange and photosynthetic pigment concentrations. We also

Susana Redondo-Gómez; Enrique Mateos-Naranjo; Luis Andrades-Moreno

2010-01-01

347

Accumulation and Remediation of Cadmium-polluted Soil by a Potential Cadmium-hyperaccumulator Chlorophytum comosum  

Microsoft Academic Search

Chlorophytum comosum was used to remediate the artificially polluted soil in a pot experiment under greenhouse conditions. The results showed that the activity of soil enzyme increased significantly in soil planted with C. comosum compared to soil not planted with C. comosum, while the concentration of cadmium in the soil reduced. The accumulation at 10 mg kg cadmium was above

Y. Wang; A. Yan; T. Wu; X. Zhang

2012-01-01

348

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

E-print Network

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

Ma, Lena

349

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...

350

Antioxidative responses to arsenic in the arsenic-hyperaccumulator Chinese brake fern (Pteris vittata L.)  

E-print Network

at 420 mg kg�1 enhanced plant growth, with 12­71% biomass increase compared to the control. The contents of non-enzymatic antioxidants (glutathione, acid-soluble thiol) followed similar trends as plant of Florida, Gainesville, FL 32611, USA b Department of Plant Pathology, North Carolina State University

Ma, Lena

351

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

E-print Network

s t r a c t a r t i c l e i n f o Article history: Received 23 December 2013 Received in revised form 19 Pteris multifida Tolerance Transformation a b s t r a c t We isolated and characterized As-resistant endophytic bacteria (AEB) from two arsenic hyperaccumula- tors. Their plant growth promoting traits

Ma, Lena

352

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

E-print Network

selenocysteine and selenate. Thus, S. albescens may accumulate more toxic forms of Se in its leaves than S accumulate less than 25 mg Se g 21 dry weight in their natural envi- ronment and cannot tolerate increased Se,000 to 15,000 mg Se g21 dry weight in their shoots (0.1%­1.5%) while growing on soils containing only 2 to 1

353

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

PubMed

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

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

2010-11-01

354

Predicting arsenic bioavailability to hyperaccumulator Pteris vittata in arsenic-contaminated soils.  

PubMed

Using chemical extraction to evaluate plant arsenic availability in contaminated soils is important to estimate the time frame for site cleanup during phytoremediation. It is also of great value to assess As mobility in soil and its risk in environmental contamination. In this study, four conventional chemical extraction methods (water, ammonium sulfate, ammonium phosphate, and Mehlich III) and a new root-exudate based method were used to evaluate As extractability and to correlate it with As accumulation in P. vittata growing in five As-contaminated soils under greenhouse condition. The relationship between different soil properties, and As extractability and plant As accumulation was also investigated. Arsenic extractability was 4.6%, 7.0%, 18%, 21%, and 46% for water, ammonium sulfate, organic acids, ammonium phosphate, and Mehlich III, respectively. Root exudate (organic acids) solution was suitable for assessing As bioavailability (81%) in the soils while Mehlich III (31%) overestimated the amount of As taken up by plants. Soil organic matter, P and Mg concentrations were positively correlated to plant As accumulation whereas Ca concentration was negatively correlated. Further investigation is needed on the effect of Ca and Mg on As uptake by P. vittata. Moreover, additional As contaminated soils with different properties should be tested. PMID:22908656

Gonzaga, Maria Isidória Silva; Ma, Lena Q; Pacheco, Edson Patto; dos Santos, Wallace Melo

2012-12-01

355

Impact of arsenic on uptake and bio-accumulation of antimony by arsenic hyperaccumulator Pteris vittata.  

PubMed

Individual uptake of As and Sb species in Pteris vittata have been investigated, but little information is available how uptake is affected if both metalloids are simultaneously present in different amounts. We investigated the uptake of antimony and its speciation in Pteris vittata cultivated in quartz substrate with, versus without, co-contamination with arsenic and a contaminated soil for 7 weeks. Applying HPLC-ICP-MS technique Sb(V), Sb(III), As(III), and As(V) could be identified as main species in aqueous extracts of roots and fronds with up to 230 mg kg(-1) of total Sb in the roots. Adding increasing amounts of As to the quartz substrate resulted in increasing uptake of Sb. In contrast to As, which is readily transferred to the fronds, Sb is primarily accumulated in the roots with Sb(V) being the dominant species (>90% of Sb). The addition of As doesn't result in enhanced translocation of Sb into the fronds. PMID:23257262

Müller, K; Daus, B; Mattusch, J; Vetterlein, D; Merbach, I; Wennrich, R

2013-03-01

356

Manganese uptake and interactions with cadmium in the hyperaccumulator— Phytolacca Americana L  

Microsoft Academic Search

In the present study, the accumulation of Mn and other metals by Phytolacca Americana L. from contaminated soils in Hunan Province, South China, was investigated. Results showed that the average concentrations of Mn in the leaves and roots reached 2198 and 80.4mgkg?1 (dry weight), respectively, with a maximum 13,400mgkg?1 in the leaves. A significant correlation was found between Mn concentrations

Kejian Peng; Chunling Luo; Wuxin You; Chunlan Lian; Xiangdong Li; Zhenguo Shen

2008-01-01

357

Hyper-accumulation capability of Silene vulgaris in relation to its phylogeny  

NSDL National Science Digital Library

The purpose of this work consisted in reviewing current literature to learn the absorption modality of these ions by the plant under study, identify the genes involved in the process and locate the evolution of this trait in the phylogenetic tree of the species.

Chi-Cheng Lin (Winowna State University;); Bruno Borsari (Winowna State University;)

2007-06-17

358

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

Microsoft Academic Search

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

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

1998-01-01

359

An International Journal of Plant ISSN 0032-0935  

E-print Network

on angiosperm hyperaccumulators. Plant hyperaccumulators are defined as having 50­100� higher concentrations on the element. Hyperaccumulation has been documented in at least 515 taxa of angiosperms. By mapping the occurrence of hyperaccumulators onto the angiosperm phylogeny, we show hyperaccumulation has had multiple

360

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

361

Identifying root exudates in field contaminated soil systems  

NASA Astrophysics Data System (ADS)

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.

Rosenfeld, C.; Martinez, C. E.

2012-12-01

362

Brassicaceae (Mustard family) Field pennycress  

E-print Network

Brassicaceae (Mustard family) Field pennycress Thlaspi arvense L. Life cycle Erect winter or summer. Back to identifying Christmas tree weeds. #12;Brassicaceae (Mustard family) Field pennycress continued

363

Abnormal accumulation of trace metals by plants  

SciTech Connect

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.

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

1996-12-31

364

Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator,  

E-print Network

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

Ma, Lena

365

Arsenic-resistant proteobacterium from the phyllosphere of arsenic-hyperaccumulating fern ( Pteris vittata L.) reduces arsenate to arsenite  

Microsoft Academic Search

An arsenic-resistant bacterium, AsRB1, was isolated from the fronds of Pteris vittata grown in a site contaminated with copper chromium arsenate. The bacterium exhibited resistance to arsenate, arsenite, and antimony in the culture medium. AsRB1, like Pseudomonas putida, grew on MacConkey and xylose-lactose-desoxycholate agars and utilized citrate but, unlike P. putida, was positive for indole test and negative for oxidase

Bala Rathinasabapathi; Suresh Babu Raman; Gina Kertulis; Lena Ma

2006-01-01

366

Arsenic Uptake by Native Fern Species in Thailand: Effect of Chelating Agents on Hyperaccumulation of Arsenic by Pityrogramma calomelanos  

Microsoft Academic Search

Nineteen native fern species collected from an area in Thailand with high arsenic concentration in soil and in ground water as a result of tin mining was screened for elevated arsenic concentration in fronds. Two species of fern were found to contain elevated arsenic in their fronds in nature: Pityrogrammacalomelanos (108–1156 µg g dried weight) and Pterisvittata (79 µg g dried weight). Under hydroponic

Jirarut Wongkongkatep; Kensuke Fukushi; Preeda Parkpian; Ronald D. DeLaune; Aroon Jugsujinda

2003-01-01

367

Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)  

Microsoft Academic Search

An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +\\/- 14 microg\\/g were amended with unpolluted soil at 1 and 3%. After aging for one, three, and six

Xin Du; Yanshan Cui; Liping Weng; Qing Cao; Yongguan Zhu

2008-01-01

368

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

E-print Network

in plant parts and extracted sap. Nickel is con- centrated in the dermal leaf and stem tissues of A. murale Laboratory, Department of Plant and Soil Sciences, University of Kentucky, N122S Agricultural Sciences North of Plant and Soil Sciences, University of Delaware, 152 Townsend Hall, Newark, DE 19717-1303, USA a r t i c

369

A single recessive gene controls cadmium translocation in the cadmium hyperaccumulating rice cultivar Cho-Ko-Koku  

Microsoft Academic Search

The heavy metal cadmium (Cd) is highly toxic to humans and can enter food chains from contaminated crop fields. Understanding\\u000a the molecular mechanisms of Cd accumulation in crop species will aid production of safe Cd-free food. Here, we identified\\u000a a single recessive gene that allowed higher Cd translocation in rice, and also determined the chromosomal location of the\\u000a gene. The

Kouichi Tezuka; Hidenori Miyadate; Kazunao Katou; Ikuko Kodama; Shinichi Matsumoto; Tomohiko Kawamoto; Satoshi Masaki; Hideki Satoh; Masayuki Yamaguchi; Kenji Sakurai; Hidekazu Takahashi; Namiko Satoh-Nagasawa; Akio Watanabe; Tatsuhito Fujimura; Hiromori Akagi

2010-01-01

370

Cd localization and speciation in a contaminated sdiment and in th Zn and Cd hy-peraccumulating plant Arabidopsis kalleri  

E-print Network

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

Boyer, Edmond

371

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

372

Impact Assessment of Mercury Accumulation and Biochemical and Molecular Response of Mentha arvensis: A Potential Hyperaccumulator Plant  

PubMed Central

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

Manikandan, R.; Sahi, S. V.; Venkatachalam, P.

2015-01-01

373

NEW MOLYBDENUM-HYPERACCUMULATOR AMONG PLANT SPECIES GROWING ON MOLYBDENUM MINE A BIOCHEMICAL STUDY ON TOLERANCE MECHANISM AGAINST METAL TOXICITY  

Microsoft Academic Search

The aim of this work was to determine metal accumulation by plants growing on three molybdenum-mine zones and their tolerance strategies. The plants from tailing, extracting and non-contaminated zones were sampled with their corresponding soils. The results show that molybdenum (Mo) and copper (Cu) were at toxic levels in soils and their levels varied in 44 collected species from 21

Masoud Mashhadi Akbar Boojar; Zahra Tavakkoli

2011-01-01

374

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

E-print Network

-rhizosphere soils de- crease considerably after growth of both plants, but the decrease is greater with T Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19717, USA a r t i c l e i n f o XAD resins into six fractions. The acid fraction was the predominant component of DOM

Sparks, Donald L.

375

Biochemical Characterization of Plant Small CTD Phosphatases and Application of CTD Phosphatase Mutant in Hyperaccumulation of Flavonoids in Arabidopsis  

E-print Network

in turn regulate the activity of SNF1-related protein kinases 2 (SnRK2) family proteins (Fujii et al., 2009; Vlad et al., 2009). 8 Transcription activation of ABA-responsive genes is mediated by bZIP type transcription factors ABFs, such as ABI5...

Feng, Yue

2011-10-21

376

The effects of copper, manganese and zinc on plant growth and elemental accumulation in the manganese-hyperaccumulator Phytolacca americana.  

PubMed

Synchrotron radiation X-ray fluorescence (SRXRF) and inductively coupled plasma mass spectrometry were used to estimate major, minor and trace elements in Cu-, Zn- and Mn-treated Phytolacca americana. The effects of the addition of Cu, Zn and Mn on morphological parameters, such as root length, shoot height, and fresh and dry weights of shoots and roots, were also examined. In addition, the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidases (GPX) and catalase (CAT) and the expression of Fe-SOD, Cu/Zn-SOD, metallothionein-2 and glutathione S-transferase (GST) exposed to the highest amounts of Cu, Zn or Mn were detected. Our results confirmed the following: (1) Zn supplementation leads to chlorosis, disturbed elemental homeostasis and decreased concentrations of micro- and macroelements such as Fe, Mg, Mn, Ca and K. Cu competed with Fe, Mn and Zn uptake in plants supplemented with 25 ?M Cu. However, no antagonistic interactions took place between Cu, Zn, Mn and Fe uptake in plants supplemented with 100 ?M Cu. Mn supplementation at various concentrations had no negative effects on elemental deficits. Mn was co-located with high concentrations of Fe and Zn in mature leaves and the concentrations of macro elements were unchanged. (2) P. americana supplemented with increased concentrations of Zn and Cu exhibited lower biomass production and reduced plant growth. (3) When plants were supplemented with the highest Zn and Cu concentrations, symptoms of toxicity corresponded to decreased SOD or CAT activities and increased APX and GPX activities. However, Mn tolerance corresponded to increased SOD and CAT activities and decreased POD and APX activities. Our study revealed that heavy metals partially exert toxicity by disturbing the nutrient balance and modifying enzyme activities that induce damage in plants. However, P. americana has evolved hyper accumulating mechanisms to maintain elemental balance and redox homeostasis under excess Mn. PMID:22796009

Zhao, Huijun; Wu, Liangqi; Chai, Tuanyao; Zhang, Yuxiu; Tan, Jinjuan; Ma, Shengwen

2012-09-01

377

Phytoremediation of Soil Trace Elements  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phytoremediation includes several distinct approaches to using plants to achieve soil remediation goals. Phytoextraction uses rare hyperaccumulator plants to accumulate in their shoots enough metals per year to achieve decontamination goals. Phytomining uses hyperaccumulators and biomass burn to pro...

378

Plant and rhizosphere processes involved in phytoremediation of metal-contaminated soils  

Microsoft Academic Search

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

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

2001-01-01

379

Effects of arsenic on concentration and distribution of nutrients in the fronds of the arsenic  

E-print Network

hyperaccumulator Pteris vittata L. Cong Tu1 , Lena Q. Ma) Soil and Water Science Department, University of Florida Pteris vittata was the first terrestrial plant known to hyperaccumulate arsenic (As). However hyperaccumulation; Nutrients; Concentration; Distribution; Pteris vittata L. 1. Introduction Arsenic (As

Ma, Lena

380

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...

381

APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 0099-2240/00/$04.00 0  

E-print Network

- extraction practices with three plant species (Silene vulgaris, Thlaspi caerulescens, and Zea mays in the rhizosphere of mycorrhizal maize was significantly higher than in rhizospheres of nonmycorrhizal S. vulgaris

Pawlowska, Teresa

382

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

SciTech Connect

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.

Kochian, L.

1995-12-01

383

Zn-bis-glutathionate is the best co-substrate of the monomeric phytochelatin synthase from the photosynthetic heavy metal-hyperaccumulator Euglena gracilis.  

PubMed

The phytochelatin synthase from photosynthetic Euglena gracilis (EgPCS) was analyzed at the transcriptional, kinetic, functional, and phylogenetic levels. Recombinant EgPCS was a monomeric enzyme able to synthesize, in the presence of Zn(2+) or Cd(2+), phytochelatin2-phytochelatin4 (PC2-PC4) using GSH or S-methyl-GS (S-methyl-glutathione), but not ?-glutamylcysteine or PC2 as a substrate. Kinetic analysis of EgPCS firmly established a two-substrate reaction mechanism for PC2 synthesis with Km values of 14-22 mM for GSH and 1.6-2.5 ?M for metal-bis-glutathionate (Me-GS2). EgPCS showed the highest Vmax and catalytic efficiency with Zn-(GS)2, and was inactivated by peroxides. The EgPCS N-terminal domain showed high similarity to that of other PCSases, in which the typical catalytic core (Cys-70, His-179 and Asp-197) was identified. In contrast, the C-terminal domain showed no similarity to other PCSases. An EgPCS mutant comprising only the N-terminal 235 amino acid residues was inactive, suggesting that the C-terminal domain is essential for activity/stability. EgPCS transcription in Euglena cells was not modified by Cd(2+), whereas its heterologous expression in ycf-1 yeast cells provided resistance to Cd(2+) stress. Phylogenetic analysis of the N-terminal domain showed that EgPCS is distant from plants and other photosynthetic organisms, suggesting that it evolved independently. Although EgPCS showed typical features of PCSases (constitutive expression; conserved N-terminal domain; kinetic mechanism), it also exhibited distinct characteristics such as preference for Zn-(GS)2 over Cd-(GS)2 as a co-substrate, a monomeric structure, and ability to solely synthesize short-chain PCs, which may be involved in conferring enhanced heavy-metal resistance. PMID:24464102

García-García, Jorge D; Girard, Lourdes; Hernández, Georgina; Saavedra, Emma; Pardo, Juan P; Rodríguez-Zavala, José S; Encalada, Rusely; Reyes-Prieto, Adrián; Mendoza-Cózatl, David G; Moreno-Sánchez, Rafael

2014-03-01

384

Phytoremediation of arsenic-contaminated groundwater using arsenic hyperaccumulator Pteris vittata L.: Effects of frond harvesting regimes and arsenic levels in refill water  

Microsoft Academic Search

A large-scale hydroponic system to phytoremediate arsenic-contaminated groundwater using Pteris vittata (Chinese brake fern) was successfully tested in a field. In this 30-wk study, three frond-harvesting regimes (all, mature, and senescing fronds) and two water-refilling schemes to compensate for evapotranspiration (high-As water of 140–180?g\\/L and low-As water of <7?g\\/L) were investigated. Two experiments (Cycle 1 and Cycle 2) were conducted

Seenivasan Natarajan; Robert H. Stamps; Lena Q. Ma; Uttam K. Saha; Damaris Hernandez; Yong Cai; Edward J. Zillioux

2011-01-01

385

Arsenic accumulation pattern in 12 Indian ferns and assessing the potential of Adiantum capillus-veneris, in comparison to Pteris vittata, as arsenic hyperaccumulator  

Microsoft Academic Search

The present study was undertaken to evaluate the ability of some Indian ferns to accumulate and tolerate arsenic. Twelve species of Indian ferns were exposed to 10mgL?1 arsenic as sodium arsenate for 15days in hydroponic system. Depending on the arsenic uptake in the plant parts –Pteris vittata, Pteris cretica, Adiantum capillus-veneris and Nephrolepis exaltata may be categorised as arsenic accumulator.

Nandita Singh; Anshita Raj; P. B. Khare; R. D. Tripathi; Sarah Jamil

2010-01-01

386

Joint effects of arsenic and cadmium on plant growth and metal bioaccumulation: A potential Cd-hyperaccumulator and As-excluder Bidens pilosa L  

Microsoft Academic Search

Joint effects of arsenic (As) and cadmium (Cd) on the growth of Bidens pilosa L. and its uptake and accumulation of As and Cd were investigated using the field pot-culture experiment. The results showed that single Cd (?25mgkg?1) and As (?50mgkg?1) treatments could promote the growth of B. pilosa, resulting in 34.5–104.4% and 21.0–43.0%, respectively, increase in the dry biomass

Yue-bing Sun; Qi-xing Zhou; Wei-tao Liu; Jing An; Zhi-Qiang Xu; Lin Wang

2009-01-01

387

The Influence of Different Growth Stages and Dosage of EDTA on Cd Uptake and Accumulation in Cd-Hyperaccumulator ( Solanum Nigrum L.)  

Microsoft Academic Search

Application of synthetic chelates such as ethylene diamine tetraacetic acid (EDTA) has been proposed as an alternative technology\\u000a for phytoextraction of contaminated soils. In a pot experiment, the effects of EDTA application at three growing stages on\\u000a growth and Cd uptake and accumulation of Solanum nigrum L. were investigated. The results showed that the 0.1 g\\/kg EDTA treatment was the most

Yuebing Sun; Qixing Zhou; Lin Wang; Weitao Liu

2009-01-01

388

Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly progress report, July 1, 1996--September 30, 1996  

SciTech Connect

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.

Kochian, L. [Cornell Univ., Ithaca, NY (United States)

1997-05-01

389

Phytoremediation of arsenic-contaminated groundwater using arsenic hyperaccumulator Pteris vittata L.: effects of frond harvesting regimes and arsenic levels in refill water.  

PubMed

A large-scale hydroponic system to phytoremediate arsenic-contaminated groundwater using Pteris vittata (Chinese brake fern) was successfully tested in a field. In this 30-wk study, three frond-harvesting regimes (all, mature, and senescing fronds) and two water-refilling schemes to compensate for evapotranspiration (high-As water of 140-180 ?g/L and low-As water of <7 ?g/L) were investigated. Two experiments (Cycle 1 and Cycle 2) were conducted using the same plants in 24 tanks with each containing 600 L of arsenic-contaminated groundwater and 32 ferns. During Cycle 1 and with initial As of 140 ?g/L, As in tanks refilled with low-As water was reduced to <10 ?g/L in 8 wks compared to <10 ?g/L in 17 wks in tanks refilled with high-As water. During Cycle 2 and with initial As of 180 ?g/L, the remediation time was reduced by 2-5 wks, indicating that more established ferns were more efficient. In areas where clean water is limiting, refilling high-As water coupled with harvesting senescing fronds is recommended for more effective As phytoremediation. PMID:21051137

Natarajan, Seenivasan; Stamps, Robert H; Ma, Lena Q; Saha, Uttam K; Hernandez, Damaris; Cai, Yong; Zillioux, Edward J

2011-01-30

390

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

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

Adrian Radu Craciun; Mikael Courbot; Fabienne Bourgis; Pietrino Salis; Pierre Saumitou-Laprade; Nathalie Verbruggen

2006-01-01

391

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 ...

392

The current status of the elemental defense hypothesis in relation to pathogens  

PubMed Central

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

Hörger, Anja C.; Fones, Helen N.; Preston, Gail M.

2013-01-01

393

The current status of the elemental defense hypothesis in relation to pathogens.  

PubMed

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

Hörger, Anja C; Fones, Helen N; Preston, Gail M

2013-01-01

394

Phytoextraction of metals and metalloids from contaminated soils.  

PubMed

The removal of inorganic contaminants by plants is termed phytoextraction. Recent studies have looked at the feasibility of phytoextraction, and demonstrate that both good biomass yields and metal hyperaccumulation are required to make the process efficient. Adding chelating agents to soil to increase the bioavailability of contaminants can sometimes induce hyperaccumulation in normal plants, but may produce undesirable environmental risks. Thus, it is necessary to investigate the mechanisms responsible for hyperaccumulation, using natural hyperaccumulators as model plant species. Recent advances have been made in understanding the mechanisms responsible for hyperaccumulation of Zn, Cd, Ni and As by plants. Attempts to engineer metal tolerance and accumulation have so far been limited to Hg, As and Cd, and although promising results have been obtained they may be some way from practical application. More fundamental understanding of the traits and mechanisms involved in hyperaccumulation are needed so that phytoextraction can be optimised. PMID:12849780

McGrath, Steve P; Zhao, Fang-Jie

2003-06-01

395

Assessing the Bioavailability of Ni in Smelter Contaminated Soils. (S11-everhart242852-oral)  

E-print Network

. 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

Sparks, Donald L.

396

Journal of Hazardous Materials 192 (2011) 16161622 Contents lists available at ScienceDirect  

E-print Network

organic matter from the rhizosphere of the hyperaccumulator Sedum alfredii on sorption of zinc and cadmium: Dissolved organic matter Cadmium Sedum alfredii Sorption Zinc a b s t r a c t Pot experiments were conducted­5]. However, potential use of hyperaccumulators in phytoremediation is limited by a lack of knowledge of many

Sparks, Donald L.

397

Chinese Science Bulletin Vol. 50 No. 1 January 2005 33 Chinese Science Bulletin 2005 Vol. 50 No. 1 33 38  

E-print Network

investigation was conducted to screen for cadmium-hyperaccumulator from 54 species in 20 weed families using and evolution. It provides a pat- entable new plant species for phytoremediation of Cd-con- taminated soils. Keywords: hyperaccumulator, cadmium, Solanum nigrum L., reme- diation of contaminated soils. DOI: 10

Ma, Lena

398

DEVELOPMENT OF BIO-BASED MOLECULAR TECHNOLOGIES FOR REMOVAL AND REAL-TIME MONITORING OF TOXIC METALS  

EPA Science Inventory

Transformation of heavy-metal related genes from a hyper-accumulator to a high-biomass species is expected to promote a zinc hyper-accumulating phenotype in the normally non-hyper-accumulating poplar. Coupling fluorescence with heavy metal proteins is anticipated to allow ...

399

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

400

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

401

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- selenocysteine (Me

402

Plant Science 195 (2012) 8895 Contents lists available at SciVerse ScienceDirect  

E-print Network

journal homepage: www.elsevier.com/locate/plantsci Review Plant defense using toxic inorganic ions Plant­insect interactions Synergy a b s t r a c t The concept of plant defense using toxic mineral hyperaccumulation) in some plant tissues. The Defensive Enhancement Hypothesis suggests that hyperaccumulation

Boyd, Robert S.

403

Metabolic adaptations to arsenic-induced oxidative stress in Pteris vittata L and Pteris ensiformis L  

E-print Network

Metabolic 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; Ascorbate; Glutathione; Hyperaccumulator; Pteris ensiformis L; Pteris vittata L; Thiobarbituric acid

Ma, Lena

404

Published: October 26, 2011 r 2011 American Chemical Society 9719 dx.doi.org/10.1021/es2018048 |Environ. Sci. Technol. 2011, 45, 97199725  

E-print Network

Uptake by Arsenic Hyperaccumulator Pteris vittata Xin Wang,,,||,z Lena Q. Ma,*,§, Bala Rathinasabapathi, including arsenic hyperaccumulator Pteris vittata, AsIII uptake mechanisms by P. vittata are unclear. In this study, we investigated AsIII uptake by P. vittata involving root radial transport from external medium

Ma, Lena

405

Plant and Soil 249: 373382, 2003. 2003 Kluwer Academic Publishers. Printed in the Netherlands.  

E-print Network

October 2002 Key words: accumulation, arsenate, hyperaccumulator, interaction, phosphate, Pteris vittata L. 373 Effects of arsenate and phosphate on their accumulation by an arsenic-hyperaccumulator Pteris vittata L. Cong Tu1 & Lena Q. Ma2 Soil and Water Science Department, University of Florida, Gainesville

Ma, Lena

406

Author's personal copy Uptake and translocation of arsenite by Pteris vittata L.: Effects of glycerol,  

E-print Network

Author's personal copy Uptake and translocation of arsenite by Pteris vittata L.: Effects aquaglyceroporin transporters, but it is unknown in arsenic- hyperaccumulator Pteris vittata. We investigated-hyperaccumulator Pteris vittata (Chinese brake fern) is capable of taking up both AsV and AsIII (Ma et al., 2001; Kertulis

Ma, Lena

407

Characteristics of arsenic accumulation by Pteris and non-Pteris ferns T. Luongo & L.Q. Ma1  

E-print Network

the mechanisms of arsenic hyperaccumulation in Pteris vittata by comparing the characteristics of arsenic accumulation in Pteris and non-Pteris ferns. Seven Pteris (P.vittata, P. Cretica Rowerii, P. Cretica Parkerii The first-known arsenic hyperaccumulator Pteris vittata L (Chinese brake fern) was discovered in 1998 (Komar

Ma, Lena

408

AREA 5 WASTE DISPOSAL RESEARCH ARTICLE Biomass reduction and arsenic transformation  

E-print Network

composting of arsenic-rich hyperaccumulator Pteris vittata L. Xinde Cao & Lena Ma & Aziz Shiralipour & Willie Arsenic-rich biomass . Arsenic speciation . Composting . Phytoextraction . Pteris vittata L . Waste and arsenic transformation during com- posting As-rich biomass of hyperaccumulator Chinese brake fern (Pteris

Ma, Lena

409

Author's personal copy Environmental and Experimental Botany 65 (2009) 282286  

E-print Network

.elsevier.com/locate/envexpbot Arsenic reduced scale-insect infestation on arsenic hyperaccumulator Pteris vittata L. Shiny Mathewsa Saissetia neglecta a b s t r a c t Arsenic hyperaccumulation by Pteris vittata L. (Chinese brake fern) may exposure (0, 5, 15 and 30 mg kg-1 ) on scale insect (Saissetia neglecta) infestation of P. vittata. Scale

Ma, Lena

410

Journal of Hazardous Materials 180 (2010) 662667 Contents lists available at ScienceDirect  

E-print Network

from contaminated groundwater by Pteris vittata L. of different ages Jorge A.G. Santos, Maria I. Silva Hyperaccumulation Groundwater a b s t r a c t Optimization of arsenic uptake by Pteris vittata may reduce arsenic-hyperaccumulators, Pteris vittata L (Chinese brake fern) is the most studied [2]. To successfully

Ma, Lena

411

Accumulation and interaction of calcium and manganese in Phytolacca americana  

Microsoft Academic Search

To further understand the hyperaccumulation of Mn, the present study investigated the accumulation of Ca and Mn and their interaction in Mn hyperaccumulator pokeweed (Phytolacca americana Linn.). Exogenous Ca was observed to have a distinctive impact on the Mn phytotoxicity and accumulation in pokeweed, but exogenous Mn had little influence on the accumulation of Ca. Both Ca and Mn accumulated

Changming Dou; Xiaoping Fu; Xincai Chen; Jiyan Shi; Yingxu Chen

2009-01-01

412

Poplar maintains zinc homeostasis with heavy metal genes HMA4 and PCS1  

Technology Transfer Automated Retrieval System (TEKTRAN)

This project has identified two large gene families, HMA and ZIP, in poplar that have been greatly expanded by the latest Salicoid genome duplication in poplar. In other species, these two families have been shown to be central in both hyperaccumulators and non-hyperaccumulators In poplar, many of t...

413

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

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

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

2008-01-01

414

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

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

Junkang Guo; Shirong Tang; Xuehai Ju; Yongzhen Ding; Shangqiang Liao; Ningning Song

415

Effects of Metal Phytoextraction Practices on the Indigenous Community of Arbuscular Mycorrhizal Fungi at a Metal-Contaminated Landfill  

Microsoft Academic Search

Phytoextraction involves use of plants to remove toxic metals from soil. We examined the effects of phyto- extraction practices with three plant species (Silene vulgaris, Thlaspi caerulescens, and Zea mays) and a factorial variation of soil amendments (either an ammonium or nitrate source of nitrogen and the presence or absence of an elemental sulfur supplement) on arbuscular mycorrhizal (AM) fungi

TERESA E. PAWLOWSKA; RUFUS L. CHANEY; MEL CHIN; IRIS CHARVAT

2000-01-01

416

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...

417

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 ...

418

EVALUATION OF FIELD PENNYCRESS AS AN OVERWINTER GREEN MANURE CROP IN CORN FOR SUPPRESSION OF WESTERN CORN ROOTWORM  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field pennycress (FP; Thlaspi arvense L.) is a winter annual species of the Brassicaceae which is a native of Europe but has a wide distribution throughout temperate North America. FP tissues contain the glucosinolate sinigrin, and release a mixture of the biocides allyl thiocyanate and allyl isoth...

419

Collecting field pennycress germplasm in Colorado and characterization of oil and root variation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field pennycress (Thlaspi arvense) has been identified as a possible source of biodiesel that may perform better in colder climates than other biodiesel fuels. A germplasm collection of the species is being maintained by the U.S. Department of Agriculture for use in research, education, and crop imp...

420

Effects of planting depth on field establishment of pennycress and light conditions on seed germination  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pennycress (Thlaspi arvense), is a promising oilseed (36% oil) with potential for biofuels and another industrial uses. A winter annual, it may be feasible for use in Midwestern double cropping systems. However, agronomic and biological issues should be studied in order to understand and overcome pr...

421

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...

422

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...

423

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

424

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

in question and is 0.01% of dry mass (DW) for cadmium (Cd), 0.1% for arsenic (As), copper (Cu), cobalt (Co of this fascinating trait, we can potentially use hyperaccumulators or their genes for phytoremediation (envi

425

Symphyotrichum ericoides populations from seleniferous and nonseleniferous soil display striking variation in selenium  

E-print Network

Symphyotrichum ericoides populations from seleniferous and nonseleniferous soil display striking, facultative metallophyte, hyperaccumulation, rhizosphere microbes, selenium, Symphyotrichum ericoides. Summary Symphyotrichum ericoides (Asteraceae) from naturally seleniferous habitat (Pine Ridge) was shown previously

426

Reverse Genetic Characterization of Cytosolic Acetyl-CoA Generation by ATP-Citrate Lyase in Arabidopsis W  

E-print Network

morphology, reduced cuticular wax deposition, and hyperaccumulation of starch, anthocyanin, and stress in ACL activity. These data indicate that ACL is required for normal growth and development alterations associated with reduced ACL expression, indicating that the observed metabolic alterations

Wurtele, Eve Syrkin

427

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

428

www.newphytologist.org 363 Blackwell Publishing Ltd  

E-print Network

in the Chinese brake fern (Pteris vittata) deters grasshopper (Schistocerca americana) herbivory Bala hyperaccumulation, elemental defense, herbivory, grasshopper, pteridophytes, Pteris vittata, heavy metals. New et al., 1992). Ma et al. (2001) reported that the Chinese brake fern, Pteris vittata

Ma, Lena

429

Phytoremediation of Cadmium-Contaminated Soils by Rorippa globosa Using Two-Phase Planting (5 pp)  

Microsoft Academic Search

Background   Phytoextraction of contaminated soils by heavy metals can provide a great promise of commercial development. Although there\\u000a are more than 400 species of hyperaccumulators found in the world, phytoremediation technology is rarely applied in field\\u000a practice for remedying contaminated soils, partially due to low biomass and long growth duration for most of discovered hyperaccumulating\\u000a plants. In order to enhance

Shu-He Wei; Qi-Xing Zhou

2006-01-01

430

Cadmium-accumulating plants.  

PubMed

Plants are categorized in three groups concerning their uptake of heavy metals: indicator, excluder, and hyperaccumulator plants, which we explain in this chapter, the former two groups briefly and the hyperaccumulators in detail. The ecological role of hyperaccumulation, for example, the prevention of herbivore attacks and a possible substitution of Zn by Cd in an essential enzyme, is discussed. As the mechanisms of cadmium hyperaccumulation are a very interesting and challenging topic and many aspects are studied worldwide, we provide a broad overview over compartmentation strategies, expression and function of metal transporting proteins and the role of ligands for uptake, transport, and storage of cadmium. Hyperaccumulators are not without reason a topic of great interest, they can be used biotechnologically for two main purposes which we discuss here for Cd: phytoremediation, dealing with the cleaning of anthropogenically contaminated soils as well as phytomining, i.e., the use of plants for commercial metal extraction. Finally, the outlook deals with topics for future research in the fields of biochemistry/biophysics, molecular biology, and biotechnology. We discuss which knowledge is still missing to fully understand Cd hyperaccumulation by plants and to use that phenomenon even more successfully for both environmental and economical purposes. PMID:23430779

Küpper, Hendrik; Leitenmaier, Barbara

2013-01-01

431

Symphyotrichum ericoides populations from seleniferous and nonseleniferous soil display striking variation in selenium accumulation.  

PubMed

Symphyotrichum ericoides (Asteraceae) from naturally seleniferous habitat (Pine Ridge) was shown previously to have selenium (Se) hyperaccumulator properties in field and glasshouse studies, and to benefit from Se through protection from herbivory. To investigate whether Se hyperaccumulation is ubiquitous in S. ericoides or restricted to seleniferous soils, the S. ericoides Pine Ridge (PR) population was compared with the nearby Cloudy Pass (CP) population from nonseleniferous soil. The S. ericoidesPR and CP populations were strikingly physiologically different: in a common garden experiment, PR plants accumulated up to 40-fold higher Se concentrations than CP plants and had 10-fold higher Se : sulfur (S) ratios. Moreover, roots of S. ericoidesPR plants showed directional growth toward selenate, while CP roots did not. Growth of both accessions responded positively to Se. Each accession grew best on its own soil. Rhizosphere soil inoculum from the S. ericoidesPR population stimulated plant growth and Se accumulation in both S. ericoidesPR and S. ericoidesCP plants, on both PR and CP soils. While the S. ericoidesPR population hyperaccumulates Se, the nearby CP population does not. The capacity of S. ericoidesPR plants to hyperaccumulate Se appears to be a local phenomenon that is restricted to seleniferous soil. Mutualistic rhizosphere microbes of the S. ericoidesPR population may contribute to the hyperaccumulation phenotype. PMID:25406635

El Mehdawi, Ali F; Paschke, Mark W; Pilon-Smits, Elizabeth A H

2014-11-18

432

Classification and identification of metal-accumulating plant species by cluster analysis.  

PubMed

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

Yang, Wenhao; Li, He; Zhang, Taoxiang; Sen, Lin; Ni, Wuzhong

2014-09-01

433

LEAD UPTAKE, TOLERANCE, AND ACCUMULATION EXHIBITED BY THE PLANTS URTICA DIOICA AND SEDUM SPECTABILE IN CONTAMINATED SOIL WITHOUT ADDITIVES  

E-print Network

Abstract — Specimens of Urtica dioica and Sedum spectabile collected from plants growing at uncontaminated sites were transplanted in Pb-contaminated soil without additives (EDTA, HEDTA) to identify their natural potential for hypertolerance and hyperaccumulation of lead. The total content of Pb in the plants was determined by atomic spectroscopy. Our research showed that the concentrated toxic levels of lead (Pb) in Sedum spectabile and Urtica dioica were about 100 or more times higher than those of non-accumulator plants. It can be concluded that these plants have a high natural potential for hypertolerance and hyperaccumulation of lead, since they can hyperaccumulate it without addition of any chelating compounds (EDTA, HEDTA) to enhance lead uptake. This makes them very promising plants for use in phytoremediation of Pb-contaminated sites.

Milena Grubor

434

The potential for heavy metal decontamination  

SciTech Connect

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.

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

435

Regulation of gemma formation in the copper moss Scopelophila cataractae by environmental copper concentrations.  

PubMed

Considerable attention has recently been focused on the use of hyperaccumulator plants for the phytoremediation of soils contaminated with heavy metals. The moss, Scopelophila cataractae (Mitt.) Broth., is a typical hyperaccumulator that is usually observed only in copper-rich environments and which accumulates high concentrations of copper in its tissues. However, many of the physiological processes and mechanisms for metal hyperaccumulation in S. cataractae remain unknown. To address this issue, we examined the mechanisms regulating gemma formation, which is considered the main strategy by which S. cataractae relocates to new copper-rich areas. From this study we found that treatment of S. cataractae with high concentrations of copper suppressed gemma formation but promoted protonemal growth. The suppressive effect was not observed by treatment with heavy metals other than copper. These results suggest the importance of copper-sensitive asexual reproduction in the unique life strategy of the copper moss, S. cataractae. PMID:21082328

Nomura, Toshihisa; Hasezawa, Seiichiro

2011-09-01

436

Characterization of selenium and sulfur accumulation across the genus Stanleya (Brassicaceae): A field survey and common-garden experiment.  

PubMed

• 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

Cappa, Jennifer J; Cappa, Patrick J; El Mehdawi, Ali F; McAleer, Jenna M; Simmons, Mark P; Pilon-Smits, Elizabeth A H

2014-04-21

437

Selected chromosome counts of the Czechoslovak flora III  

Microsoft Academic Search

Chromosome numbers compared with as yet published data are given for the following 12 Phanerogams (both native species and\\u000a aliens) from Czechoslovakia:Ambrosia trifida L.,Cardamine chelidonia L.,Dephne cneorum L.,Epipactis albensis\\u000a Nováková etRydlo,Linum flavum L.subsp flavum, Lunaria rediviva L.,Nepeta grandiflora M.BIEB.,Reseda luteola L.,Thlaspi montanum L.,Tithymalus salicifolius (Host)Klotzsch etGarcke,Tithymalus virgultosus (Klokov) Holub andVerbascum speciosum\\u000a Schrad. subsp.speciosum. The chromosome number 2n=40 is presented for

Anna Krahulcová

1991-01-01

438

Spatial genetic structure within a metallicolous population of Arabidopsis halleri, a clonal, self-incompatible and heavy-metal-tolerant species  

Microsoft Academic Search

Arabidopsis halleri , a close wild relative of A. thaliana , is a clonal, insect-pollinated herb tolerant to heavy metals (Zn, Pd, Cd) and a hyperaccumulator of Zn and Cd. It is of partic- ular interest in the study of evolutionary processes and phytoremediation. However, little is known about its population gene flow patterns and the structure of its genetic

FABIENNE VAN R OSSUM; ISABELLE BONNIN; MAXIME PAUWELS; DANIEL PETIT; PIERRE SAUMITOU-LAPRADE

2004-01-01

439

Physical, Chemical and Biological Characterisation of a Steelworks Waste Site at Port Kembla, NSW, Australia  

Microsoft Academic Search

Large spoils of metal-rich filtercake from the Port Kembla BHP steelworks were characterised by certain physical, chemical and biological parameters. The vegetation was assessed for potential metal hyperaccumulators and the presence of arbuscular mycorrhizae in the rhizospheres. Fresh filtercake (4 yr). Among the naturally colonising plants, Ricinus communis and Sonchus oleraceus are regarded the most suitable options for zinc and

A. G. Khan; T. M. Chaudhry; W. J. Hayes; C. S. Khoo; L. Hill; R. Fernandez; P. Gallardo

1998-01-01

440

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

441

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

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

442

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

443

Draft Genome Sequence of Stenotrophomonas maltophilia SeITE02, a Gammaproteobacterium Isolated from Selenite-Contaminated Mining Soil  

PubMed Central

Stenotrophomonas maltophilia strain SeITE02 was isolated from the rhizosphere of the selenium-hyperaccumulating legume Astragalus bisculcatus. In this report, we provide the 4.56-Mb draft genome sequence of S. maltophilia SeITE02, a gammaproteobacterium that can withstand high concentrations of selenite and reduce these to elemental selenium. PMID:24812214

Bertolini, Cristina; van Aerle, Ronny; Lampis, Silvia; Moore, Karen A.; Paszkiewicz, Konrad; Butler, Clive S.

2014-01-01

444

Nickel speciation in Sebertia acuminata, a plant growing on a lateritic soil of New Caledonia  

Microsoft Academic Search

Nickel speciation in a nickel hyperaccumulating plant (Sebertia acuminata) and its associated soil of southern New Caledonia was studied using various analytical methods. The soil is formed of iron oxides (goethite, hematite), which contain almost all the nickel. The available nickel is probably linked to the organic matter in the litter. Sebertia acuminata, acts as a nickel pump, and concentrates

Nicolas Perrier; Fabrice Colin; Tanguy Jaffré; Jean-Paul Ambrosi; Jérôme Rose; Jean-Yves Bottero

2004-01-01

445

Assessing nickel bioavailability in smelter-contaminated soils Jeffrey L. Everhart a,, David McNear Jr. a  

E-print Network

%, and in total Ni from 63 to 22,000mg/kg. Oat (Avena sativa), a nonhyperaccumulator, and Alyssum murale: Nickel uptake; Bioavailability; Alyssum murale; Avena sativa; Hyperaccumulators; Phytoremediation 1 was not the case for A. sativa. Furthermore, the Ni specific bacterial biosensor was successful in predicting Ni

Sparks, Donald L.

446

Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species  

Microsoft Academic Search

Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled

Jin-Hong Qian; Adel Zayed; Yong-Liang Zhu; Mei Yu; Norman Terry

1999-01-01

447

Timing of phosphate application affects arsenic phytoextraction by Pteris vittata L. of different ages  

E-print Network

evaluated. The hydroponic experiment consisted of three plant ages (A45d, A90d and A180d) and three P; Hyperaccumulation; Hydroponic 1. Introduction Arsenic is of great environmental concern due to its carcin- ogen). In a hydroponic system spiked with 150 mg LÃ?1 arsenic, the plant accumulated up to 27,000 mg kgÃ?1 arsenic (Wang et

Ma, Lena

448

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...

449

Selenium accumulation protects plants from herbivory by Orthoptera via toxicity and deterrence.  

PubMed

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

Freeman, John L; Lindblom, Stormy Dawn; Quinn, Colin F; Fakra, Sirine; Marcus, Matthew A; Pilon-Smits, Elizabeth A H

2007-01-01

450

Phytoaccumulation of Lead by Selected Wetland Plant Species  

Microsoft Academic Search

Several anthropogenic activities lead to the production of substantial amounts of aqueous effluents that contain various toxic trace and heavy metals and which pose potential threats to the wild habitat of wetlands. As a part of the remediation of heavy metals, it is necessary to identify some aquatic hyperaccumulator plants. To this end, a greenhouse study was conducted to investigate

Tapan Adhikari; Ajay Kumar; M. V. Singh; A. Subba Rao

2010-01-01

451

Mechanisms of cadmium detoxification in cattail ( Typha angustifolia L.)  

Microsoft Academic Search

Cadmium (Cd) is a widespread heavy metal pollutant and environmental and human health hazard, which may be partially resolved using green and cost-effective phytoremediation techniques. However, the efficiency of phytoremediation is often limited by the small biomass of Cd-hyperaccumulator plants. Although cattail (Typha angustifolia L.) is tolerant of heavy metals and has a high biomass, there is little information available

Weifeng Xu; Weiming Shi; Feng Yan; Biao Zhang; Jiansheng Liang

2011-01-01

452

Assessment of Bioaccumulation of Heavy Metal by Pteris Vittata L. Growing in the Vicinity of Fly Ash  

Microsoft Academic Search

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

Alka Kumari; Brij Lal; Yogesh B. Pakade; Piar Chand

2011-01-01

453

Herbivory induces a ROS burst and the release of volatile organic compounds in the fern Pteris vittata L  

Microsoft Academic Search

The arsenic hyper-accumulating fern, Pteris vittata L., was studied to investigate the behavior of lower plants in response to both mechanical (MW) and herbivore wounding (HW). To this end, the cotton leaf worm Spodoptera littoralis was fed on P. vittata and the volatile organic compound (VOC) emission was detected from the fern's head space by using solid phase micro extraction

Gloria Imbiscuso; Antonio Trotta; Massimo Maffei; Simone Bossi

2009-01-01

454

Phytoremediation of an Arsenic-Contaminated Site Using Pteris vittata L.: A Two-Year Study  

Microsoft Academic Search

A field study was conducted to determine the efficiency of Chinese brake fern (Pteris vittata L.), an arsenic hyperaccumulator, on removal of arsenic from soil at an arsenic- contaminated site. Chinese brake ferns were planted on a site previously used to treat wood with chromated copper arsenate (CCA). Arsenic concentrations in surface and profile soil samples were determined for 2000,

G. M. Kertulis-Tartar; L. Q. Ma; C. Tu; T. Chirenje

2006-01-01

455

The Potential of Thelypteris palustris and Asparagus sprengeri in Phytoremediation of Arsenic Contamination  

Microsoft Academic Search

The potential of two plants, Thelypteris palustris (marsh fern) and Asparagus sprengeri (asparagus fern), for phytoremediation of arsenic contamination was evaluated. The plants were chosen for this study because of the discovery of the arsenic hyperaccumulating fern, Pteris vittata (Ma et al., 2001) and previous research indicating asparagus fern's ability to tolerate >1200 ppm soil arsenic. Objectives were (1) to

LaShunda L. Anderson; Maud Walsh; Amitava Roy; Christopher M. Bianchetti; Gregory Merchan

2010-01-01

456

Arsenic Uptake and Accumulation in Fern Species Growing at Arsenic-Contaminated Sites of Southern China: Field Surveys  

Microsoft Academic Search

Aiming at searching for new arsenic (As) hyperaccumulators, field surveys were conducted at 12 As-contaminated sites located in Guangxi and Guangdong Provinces of southern China. Samples of 24 fern species belonging to 16 genera and 11 families as well as their associated soils were collected and As concentrations in plant and soil samples were determined by inductively coupled plasma-atomic emission

H. B. Wang; Z. H. Ye; W. S. Shu; W. C. Li; M. H. Wong; C. Y. Lan

2006-01-01

457

Characterization of pteris vittata rhizosphere during treatment of arsenite in hydroponics  

Microsoft Academic Search

Arsenic accumulation by hyperaccumulator, Pteris vittata, when exposed to arsenite in hydroponics is comparable to that when exposed to arsenate while arsenite uptake is considerably slower than arsenate uptake. Arsenite species around root and that in the incubating solution were analyzed to investigate arsenite oxidation in hydroponics. XANES analysis of the fern roots showed that arsenate predominated in all parts

Yi Huang; Masayoshi Hatayama; Chihiro Inoue

2010-01-01

458

Variability of Grain Arsenic Concentration and Speciation in Rice (Oryza sativa L.)  

E-print Network

As III -tris-thiolate complexes. In As hyper-accumulating P. vittata, As V is reduced to As III in the frond for storage. Similar to various metal over-accumulating plants, P. vittata has a greater concentration of As in fronds than roots (Wang et...

Pillai, Tushara Raghvan

2011-02-22

459

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 ...

460

Cadmium phytoextraction potential of different Alyssum species  

Microsoft Academic Search

This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyperaccumulator, and two populations of Alyssum

R. Barzanti; I. Colzi; M. Arnetoli; A. Gallo; S. Pignattelli; R. Gabbrielli; C. Gonnelli

2011-01-01

461

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

of metals. Thèse materials are usually spread on landiïll sites. Phytoremediation couid be a stategy sédiment. Keywords: Arabidopsis halleri, cadmium (Cd), hyperaccumulation, phytoextraction, sédiment on contaminated and uncontaminated soil [9, 17|. Despite thèse numerous studies, the mechanisms of cadmium

Paris-Sud XI, Université de

462

Environmental and Experimental Botany 66 (2009) 242248 Contents lists available at ScienceDirect  

E-print Network

Received in revised form 27 February 2009 Accepted 2 March 2009 Keywords: Arabis paniculata Cadmium Non.V. 1. Introduction Hyperaccumulators of heavy metals have the potential to be used in phytoremediation, the mechanisms responsible for Cd detoxification in the roots are unclear. Cadmium is a reactive heavy metal

Ma, Lena

463

Root-Secreted Nicotianamine from Arabidopsis halleri Facilitates Zinc Hypertolerance by Regulating Zinc Bioavailability1[W][OPEN  

PubMed Central

Hyperaccumulators tolerate and accumulate extraordinarily high concentrations of heavy metals. Content of the metal chelator nicotianamine (NA) in the root of zinc hyperaccumulator Arabidopsis halleri is elevated compared with nonhyperaccumulators, a trait that is considered to be one of the markers of a hyperaccumulator. Using metabolite-profiling analysis of root secretions, we found that excess zinc treatment induced secretion of NA in A. halleri roots compared with the nonhyperaccumulator Arabidopsis thaliana. Metal speciation analysis further revealed that the secreted NA forms a stable complex with Zn(II). Supplying NA to a nonhyperaccumulator species markedly increased plant zinc tolerance by decreasing zinc uptake. Therefore, NA secretion from A. halleri roots facilitates zinc hypertolerance through forming a Zn(II)-NA complex outside the roots to achieve a coordinated zinc uptake rate into roots. Secretion of NA was also found to be responsible for the maintenance of iron homeostasis under excess zinc. Together our results reveal root-secretion mechanisms associated with hypertolerance and hyperaccumulation. PMID:25118254

Tsednee, Munkhtsetseg; Yang, Shun-Chung; Lee, Der-Chuen; Yeh, Kuo-Chen

2014-01-01

464

The effect of EDTA and citric acid on phytoremediation of Cd, Cr, and Ni from soil using Helianthus annuus  

Microsoft Academic Search

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

Cafer Turgut; M. Katie Pepe; Teresa J. Cutright

2004-01-01

465

Characteristics of heavy metal uptake by plant species with potential for phytoremediation and phytomining  

Microsoft Academic Search

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

T. V. Nedelkoska; P. M. Doran

2000-01-01

466

Phytoremediation of metals, metalloids, and radionuclides  

Microsoft Academic Search

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

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

2002-01-01

467

Metal-accumulating plants: The biological resource and its commercial exploitation is soil clean-up technology  

SciTech Connect

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.

Baker, A.J.M. [Univ.