Search

The enrichment and transfer of 8 heavy metals of Equisetum ramosissimum and Pteris vittata growing naturally close to edge of the sewage pool in Bencun Pb-Zn Tailing, Eastern Guangdong were investigated. The results indicated that the pollution of Cd, Pb, Hg, Zn was very severe in this tailing, followed by Cu and Mn. The potential ecological risk of heavy metals was assessed to be very strong based on soil background values of Guangdong Province and at high risk according to criteria of the second grade State Soil Environmental Quality Standard, and Cd, Hg, Pb were the main factors leading to potential ecological risk. The content of 8 heavy metals in the two ferns did not reach critical content of hyperaccumulator, so neither of them was typical hyperaccumulator, but both had a certain tolerance to these heavy metal pollution. Underground parts of Pteris vittata had an enrichment coefficient above 1 and that of Equisetum ramosissimum had a value near 1, therefore the two ferns could be utilized as potential enrichment plants. The two ferns have strong adaptability to the tailing habitat and can be used as pioneers in ecological restoration of Pb-Zn tailings.

Six previously undescribed cytochalasans, ueckerchalasins A−E and 4′-hydroxycytochalasin J 3 , together with eight known congeners, were isolated from solid cultures of the endophytic fungus Diaporthe ueckerae SC-J0123 which was originally isolated from the leaves of Pteris vittata L. Their structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray diffraction, and theoretical simulations of ECD spectra and 13C NMR shifts. Ueckerchalasins A–C have a carbon-carbon bridge between C-14 and C-20, forming a rare 5/6/6/7-fused heterocyclic core. Ueckerchalasins C and D displayed selective activity against human carcinoma HeLa and HepG2 cells. Ueckerchalasins C was also active against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). Six undescribed cytochalasans, including ueckerchalasins A–C with an unusual tetracyclic skeleton, were isolated from a Pteris vittata leaf-derived Diaporthe ueckerae endophyte. Ueckerchalasins C and D were selectively active against carcinoma HeLa and HepG2 cells and ueckerchalasin C was also active against Staphylococcus aureus and MRSA. [Display omitted] • Six undescribed cytochalasans from a Pteris vittata leaf-derived Diaporthe ueckerae endophyte. • Ueckerchalasins A–C possess an unusual tetracyclic skeleton. • Ueckerchalasins C and D were selectively active against carcinoma HeLa and HepG2 cells. • Ueckerchalasin C was also active against Staphylococcus aureus and MRSA. [ABSTRACT FROM AUTHOR]

In this work, arsenic (As) accumulation and distribution over time in Pteris vittata young fronds from adult plants and in whole plantlets, grown on a highly contaminated As-soil, was determined by μ-XRF. A linear increase in As content up to 60 days was found in young fronds at different times, and a progressive distribution from the apex to the base of the fronds was observed. In whole plantlets, As signal was detectable from 9 to 20 days in the apex of a few fronds and fiddleheads. Later, up to 60 days, As was localized in all fronds, in the rhizome and in basal part of the roots. The dynamics of expression of As-related genes revealed a good correlation between As content and the level of the As (III)-antiporter PvACR3 transcript in plantlets roots and fronds and in young fronds. Moreover, the transcription of As (V)-related gametophytic genes PvGAPC1, PvOCT4 increases over time during As accumulation while PvGSTF1 is expressed only in roots. Here, we demonstrate the suitability of the μ-XRF technique to monitor As accumulation, which allowed us to propose that As is initially directly transported to fiddleheads and apex of fronds, is later distributed to the whole fronds and simultaneously accumulated in the rhizome and roots. We also provide indications on the expression of candidate genes possibly involved in As (hyper)accumulation. [Display omitted] • By means of μ-XRF we established the accumulation of As in plantlets and young fronds of P. vittata. • We provide new evidence on the distribution of As in the different organs of whole plantlets over time. • We evaluated the expression in fern organs of genes involved in As accumulation. [ABSTRACT FROM AUTHOR]

The impact of siderophore produced by arsenic-resistant bacterium Pseudomonas PG12 on FeAsO 4 dissolution and plant growth were examined. Arsenic-hyperaccumulator Pteris vittata was grown for 7 d in 0.2-strength Fe-free Hoagland solution containing FeAsO 4 mineral and PG12-siderophore or fungal-siderophore desferrioxamine B (DFOB). Standard siderophore assays indicated that PG12-siderophore was catecholate-type. PG12-siderophore was more effective in promoting FeAsO 4 dissolution, and Fe and As plant uptake than DFOB. Media soluble Fe and As in PG12 treatment were 34.6 and 3.07 μM, 1.6- and 1.4-fold of that in DFOB. Plant Fe content increased from 2.93 to 6.24 g kg −1 in the roots and As content increased from 14.3 to 78.5 mg kg −1 in the fronds. Besides, P. vittata in PG12 treatment showed 2.6-times greater biomass than DFOB. While P. vittata fronds in PG12 treatment were dominated by AsIII, those in DFOB treatment were dominated by AsV (61–77%). This study showed that siderophore-producing arsenic-resistant rhizobacteria may have potential in enhancing phytoremediation of arsenic-contaminated soils. [ABSTRACT FROM AUTHOR]

Antimonite (SbIII) is transported into plants via aquaglyceroporin channels but it is unknown in As-hyperaccumulator Ptreis vittata (PV). We tested the effects of SbIII analogs (arsenite-AsIII, glycerol, silicic acid-Si, and, glucose), antimonate (SbV) analog (phosphate-P), and aquaglyceroporin transporter inhibitor (silver, Ag) on the uptake of SbIII or SbV by PV gametophytes. PV gametophytes were grown in 20% Hoagland solution containing 65 μM SbIII or SbV and increasing concentrations of analogs at 65–6500 μM for 2 h or 4 h under sterile condition. After exposing to 65 μM Sb for 2 h, PV accumulated 767 mg/kg Sb in SbIII treatment and 419 mg/kg in SbV treatment. SbIII uptake by PV gametophytes was not impacted by glycerol or AsIII nor aquaglyceroporin inhibitor Ag during 2 h exposure. While Si increased SbIII uptake and glucose decreased SbIII uptake by PV gametophytes, the impact disappeared during 4 h exposure. Under P-sufficient condition, P increased SbIII uptake and decreased SbV uptake during 2 h exposure, but the effect again disappeared after 4 h. After being P-starved for 2 weeks, P decreased SbIII with no effect on SbV uptake during 2 h exposure. Our results indicated that: 1) PV gametophytes could serve as an efficient model to study Sb uptake, and 2) unique SbIII uptake by PV may be related to its trait of As hyperaccumulation. [ABSTRACT FROM AUTHOR]

A survey was undertaken, in arsenic (As) contaminated area of the Nadia district, West Bengal, India, to find native As accumulator plants. As was determined both in soil and plant parts. The results showed that the mean translocation factor ofPteris vittataL,Phragmites karka(Cav.) Trin. Ex. Steud andChristella dentataForssk were higher than 1. It thus appeared that these plants can be efficient accumulators of As. Phytoremediation ability ofC. dentataandP. karkawas evaluated and compared with known As-hyperaccumulators -P. vittataandAdiantum capillus venerisL. Plants were grown in the As spiked soil (25, 50, 75 and 100 mg kg−1). As accumulation was found to be highest inP. vittata, 117.18 mg kg−1in leaf at 100 mg kg−1As treatment, followed byA. capillus veneris,P. karkaandC. dentatabeing 74, 83.87 and 40.36 mg kg−1, respectively. Lipid peroxidation increased after As exposure in all plants. However, the antioxidant enzyme activity and molecules concentration also increased which helped the plants to overcome As-induced oxidative stress. The study indicates thatP. karkaandC. dentatacould be considered as As-accumulators and find application for As-phytoextraction in field conditions. [ABSTRACT FROM AUTHOR]

The potential of arsenic-resistant bacteria in association withPteris vittatato reduce the level of arsenic from soil was studied. The physicochemical characteristics of contaminated paddy soil were analyzed, and 3 bacterial isolates amongst 11 were screened and were selected for further study. These three isolates were characterized by 16S rDNA sequencing and identified asBacillus altitudinisStrain SS8 (KJ432582),Bacillus megateriumStrain SS9 (KJ432583) andLysinibacillussp. Strain SS11 (KJ432584). Of these,Lysinibacillussp. Strain SS11 displayed arsenic tolerance of 3256 mg L−1for arsenate and 1136 mg L−1for arsenite. Additionally, it showed bioaccumulation capacity of 23.43 mg L−1for arsenate and 5.65 mg L−1for arsenite. It also showed resistance to other heavy metals, especially towards iron, copper and chromium. It was also observed thatPteris vittatawas able to take up more arsenic and iron from soil in the presence of these bacterial strains than in their absence, leading to contaminant-free soil. Thus, this system appears to be an effective bioremediating process to remove arsenic from contaminated soil. [ABSTRACT FROM AUTHOR]

We compared four methods to extract arsenic (As) from three different plants containing different As levels for As speciation with the goal of developing a more efficient method, i.e., As-hyperaccumulator Pteris vittata at 459–7714 mg kg − 1 , rice seedling at 53.4–574 mg kg − 1 , and tobacco leaf at 0.32–0.35 mg kg − 1 . The four methods included heating with dilute HNO 3 , and sonication with phosphate buffered solution, methanol/water, and ethanol/water, with As being analyzed using high-performance liquid chromatography coupled with inductively-coupled plasma mass spectrometry (HPLC–ICP-MS). Among the four methods, the ethanol/water method produced the most satisfactory extraction efficiency (~ 80% for the roots and > 85% for the fronds) without changing As species based on P. vittata . The lower extraction efficiency from P. vittata roots was attributed to its dominance by arsenate (82%) while arsenite dominated in the fronds (89%). The ethanol/water method used sample:solution ratio of 1:200 (0.05 g:10 mL) with 50% ethanol and 2 h sonication. Based on different extraction times (0.5–2 h), ethanol concentrations (25–100%) and sample:solution ratios (1:50–1:300), the optimized ethanol/water method used less ethanol (25%) and time (0.5 h for the fronds and 2 h for the roots). Satisfactory extraction was also obtained for tobacco leaf (78–92%) and rice seedlings (~ 70%) using the optimized method, which was better than the other three methods. Based on satisfactory extraction efficiency with little change in As species during extraction from three plants containing different As levels, the optimized method has the potential to be used for As speciation in other plants. [ABSTRACT FROM AUTHOR]

Background and aims: Concentrations of chemical analogs arsenic (As) and phosphorus (P) were measured in As-hyperaccumulator ( Pteris vittata; PV) and three non As-hyperaccumulators ( Thelypteris kunthii, Nephrolepsis brownii, and N. falcata) to draw inferences regarding their uptake from soils to roots and translocation to fronds and spores. Methods: Frond and root samples of 150 ferns at peak spore maturation were collected with associated soils between July 2012 and July 2014. Results: Arsenic in PV spores (45.4-336 mg kg) exceeded soil As (0.60-111 mg kg) in all sites and at clean sites (0.60-1.17 mg kg) for non-hyperaccumulator spores (1.83-8.60 mg kg). In PV, As in fronds and spores correlated positively with soil As ( r = 0.71-0.74) with bioconcentration factors (tissue As:soil As) of 14.3-654 and 3.26-53.6 compared to 0.08-0.44 and 0.03-8.37 for three non-hyperaccumulators. However, P in PV spores (1977-4832 mg kg) correlated negatively with frond (1028-2439 mg kg; r = −0.43) and soil (76.2-170 mg kg; r = −0.34) P. Conclusions: PV hyperaccumulates As into fronds and spores from soils with trace As. Since PV spores constituted ~9 % of frond biomass, the elevated spore As may deserve further investigation in their role as a potential health hazard and metal cycling. [ABSTRACT FROM AUTHOR]

Panax notoginseng is a well-known phytomedicine used all over the world. In recent years, a certain As contamination of the herb appeared in its planting area due to elevated soil As concentration. We investigated the feasibility of intercropping with Pteris vittata, an As hyperaccumulator, on the reduction of As accumulation in Panax notoginseng and As transfer and transformation in soil-plant system. Results showed that, intercropping could decrease the As concentrations of Panax notoginseng by 9.1-54.3 and 30.9-54.3% and increase the biomasses by 40.7-211.6 and 2.1-153.3 %, respectively, in the H-As (soil As 400.4 mg/kg) and M-As (soil As 85.3 mg/kg) treatments. Compared to the monoculture, the ratio of the nonspecifically adsorbed As in soil was decreased by 17.8 and 34.3 %, and the As transfer factor of Panax notoginseng was increased by 22.2 and 66.3 %, respectively, in H-As and M-As treatments. For As speciation, As(III) and As(V) could be detected at the same time only in root and xylem sap of Panax notoginseng in the H-As treatment, and intercropping could increase the ratios of As(III) by 97.8 and 72.4 %, respectively. In summary, intercropping with Pteris vittata is an applicable approach to reduce the As accumulation in Panax notoginseng. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the glucosidase inhibitory and cytotoxic activities of five selected edible and medicinal ferns, namely, Blechnum orientale, Davallia denticulata, Diplazium esculentum, Nephrolepis biserrata, and Pteris vittata. Methods: The aqueous extracts of the five ferns were prepared by water extraction at 90 °C for 1 h. Antiglucosidase assay was used to determine the effect of each extract on yeast alpha-glucosidase activity in vitro. Cytotoxicity was evaluated using methylthiazol tetrazolium assay on chronic myelogenous leukaemia cell line (K562). The phenolic, hydroxycinnamic acid, flavonoid and proanthocyanidin contents of the extracts were also determined. Results: The a-glucosidase inhibitory activity of D. esculentum (half maximal effective concentration, EC50 = 6.85 µg/ml) was considerably stronger than that of myricetin (EC50 = 53.21 µg/ml). B. orientale, D. esculentum, N. biserrata, and P. vittata were cytotoxic to K562 cells. P. vittata had the strongest cytotoxicity, although it was less potent than 5-fluorouracil. D. denticulata had the highest phenolic, hydroxycinnamic acid and flavonoid contents of all the extracts while B. orientale had the highest proanthocyanidin content. Conclusion: Among the five ferns evaluated, D. esculentum is a potential source of an antidiabetic agent and is recommended for further investigation in this regard. All the fern extracts, except D. denticulata, exhibited dose-dependent cytotoxicity against K562 cells. [ABSTRACT FROM AUTHOR]

To investigate whether phytoremediation can remove arsenic from the contaminated area, a study was conducted for three consecutive years to determine the efficiency of Pteris vittata, Adiantum capillus veneris, Christella dentata and Phragmites karka, on arsenic removal from the arsenic contaminated soil. Arsenic concentrations in the soil samples were analysed after harvesting in 2009, 2010 and 2011 at an interval of 6 months. Frond arsenic concentrations were also estimated in all the successive harvests. Fronds resulted in the greatest amount of arsenic removal. Root arsenic concentrations were analysed in the last harvest. Approximately 70 % of arsenic was removed by P. vittata which was recorded as the highest among the four plant species. However, 60 % of arsenic was removed by A. capillus veneris, 55.1 % by C. dentata and 56.1 % by P. karka of arsenic was removed from the contaminated soil in 3 years. [ABSTRACT FROM AUTHOR]

A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community. [ABSTRACT FROM AUTHOR]

A significant proportion of arsenic (As)-contaminated sites are temporarily or permanently under reducing condition, which may affect phytoextraction efficiency using the As-hyperaccumulator Pteris vittata L. In this work, a pot experiment was conducted to investigate the solubility and redox species of As in soil. The uptake of As by two populations of P. vittata and As-tolerant grass Holcus lanatus under different water regimes was examined. Waterlogging decreased the redox potential from 350 to−50 mV, leading to an approximately 40% reduction of As(V) to As(III) and an increased dissolved As concentration by 150%–300%. The changes in the speciation and concentration of As influenced its uptake by plants. A population collected from a temporarily waterlogged riverside in Guangxi province (GX population) had ninefold higher shoot As concentration under the waterlogged condition than that under the non-waterlogged condition, indicating that it preferred taking up As in the form of As(III). By contrast, a population of P. vittata collected from a dry land in Yunnan province (YN population) and H. lanatus demonstrated a preference to As(V). The GX population was an appropriate species for the phytoextraction of waterlogged sites. These results implied the importance of habitat ecology on the extraction efficiency of hyperaccumulators. [ABSTRACT FROM AUTHOR]

On March 11, 2011, one of the negative effects of the tsunami phenomenon that devastated the Pacific coast of the Tohoku district in Japan was the deposition of a wide range of arsenic (As) contamination to the soil. To remediate such a huge area of contamination, phytoremediation byPteris vittata, an As-hyperaccumulator, was considered. To evaluate the efficacy of applyingP. vittatato the area, the salt tolerance ofP. vittataand the phytoextraction of As from soil samples were investigated. For the salt tolerance test, spore germination was considerably decreased at an NaCl level of more than 100 mM. At 200 mM, the gametophytes exhibited a morphological defect. Furthermore, the growth inhibition ofP. vittatawas observed with a salinity that corresponded to 66.2 mS/m of electric conductivity (EC) in the soil. A laboratory phytoremediation experiment was conducted using As-contaminated soils for 166 days.P. vittatagrew and accumulated As at 264 mg/kg-DW into the shoots. Consequently, the soluble As in the soil was evidently decreased. These results showed thatP. vittatawas applicable to the phytoremediation of As-contaminated soil with low salinity as with the contamination caused by the 2011 tsunami. [ABSTRACT FROM PUBLISHER]

Phytoextraction is a cost-effective and eco-friendly technology to remove arsenic (As) from contaminated soil using plants and associated microorganisms. Pteris vittata is the most studied As hyperaccumulator, which effectively takes up inorganic arsenate via roots. Arsenic solubilization and speciation occur prior to plant absorption in the rhizosphere, which play a key role in As phytoextraction by P. vittata. This study investigated the metabolomic correlation of P. vittata and associated rhizospheric microorganisms during As phytoextraction. Three-month pot cultivation of P. vittata in As polluted soil was conducted. In rhizosphere, an increase of water-soluble As concentration and a decrease of pH was observed in the second month, suggesting acidic metabolites as a possible cause of As solubilization. A correlation network was built to elucidate the interactions among metabolites, bacteria and fungi in the rhizosphere of P. vittata. Our results demonstrate that the plant is the major driving force of rhizospheric microbiota generation, and both microbial community and metabolites in rhizosphere of P. vittata correlate to increased bioavailable As. Multi-omics analysis revealed that pterosins enrich microbes that potentially promote As phytoextraction. This study extends the current view of rhizospheric plant-microbes synergistic effects of hyperaccumulators on phytoextraction, which provides clues for developing efficient As phytoremediation approaches. [Display omitted] • Pteris vittata decreased the pH value of rhizospheric soil within two months. • Rhizospheric microbiome and metabolome correlated to increasing bioavailable As. • Secreted metabolites shaped rhizospheric bacteria & fungi community of P. vittata. • Pterosins positively associated with microbes which promote As phytoextraction. • Pterosins in rhizosphere of P. vittata positively correlated to bioavailable As. [ABSTRACT FROM AUTHOR]

Phytoremediation of arsenic contamination using the hyperaccumulatorPteris vittatais an active area of research. However, the mechanism for the uptake of arsenic inP. vittataremains unclear, due to the absence of methods to monitor this process. This study utilized synchrotron radiation X-ray fluorescence (XRF) spectroscopy and X-ray absorption near-edge structure (XANES) to continuously observein situarsenic in livingP. vittata. The results showed that the reduction of arsenic(V) to arsenic(III) occurred simultaneously with an increase in frond arsenic, suggesting the reduction affected arsenic uptake.In situXRF measurements of livingP. vittataaccurately characterized arsenic uptake butin situXANES could not be used on live plants without using methods to prevent radiation damage. A novel approach is reported to investigate the changes of elements in plants. [ABSTRACT FROM AUTHOR]

Background: Morphological and ploidy changes of the arsenic hyperaccumulator, Chinese brake fern (Pteris vittata) callus tissue are described here to provide insight into fern life cycle biology and for possible biotechnology applications. Pteris vittata callus was studied using transmission and scanning electron microscopy, and flow cytometry. Results: Callus induction occurred both in light and dark culture conditions from prothallus tissues, whereas rhizoid formation occurred only in dark culture conditions. Callus tissues contained two types of cells: one actively dividing and the other containing a single large vacuole undergoing exocytosis. Sporophytes regenerated from callus asynchronously form clusters of cells in a manner apparently analogous to direct organogenesis. Extracellular matrices were observed in actively-growing callus and at the base of regenerating sporophytes. Callus tissue nuclei were found to be primarily diploid at induction and throughout maintenance of cultures indicating that callus cell fate is determined at induction, which closely follows apogamous sporophyte development. Presence of a dense extracellular matrix in conjunction with sporophyte development suggests a link between the suspensor-like activity of the embryonic foot during normal fern embryo development and the suspected functions of extracellular matrices in angiosperms. Conclusions: Further investigation could lead to a better understanding of genes involved in P. vittata embryo development and apogamous sporophyte development. The methodology could be useful for in vitro propagation of rare and valuable fern germplasm. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) and arsenic often co-occur at polluted sites, but remediation strategies for this are scarce. In this study, the effect of bacterial inoculation on plant growth and arsenic uptake by Pteris vittata and phenanthrene dissipation was investigated hydroponically using an arsenate-reducing and PAH-degrading Pseudomonas isolate. In a 12-d experiment, despite reduced dry weight in some cases, the isolate generally promoted the growth of P. vittata . The aboveground and belowground biomass increased by 21.0–38.7% and 3.5–66.3%, respectively. In addition, bacterial inoculation greatly enhanced arsenic uptake by P. vittata compared to un-inoculated treatments (from 246.7–438.9 and 102.6–231.4 to 754.1–1425.7 and 121.5–351.4 mg kg −1 As in aboveground and belowground biomass, respectively). Accordingly, arsenic transfer factor increased by 116–315%. The enhancement was attributed to the bacteria-mediated As(V) reduction in growth media. A dissipation of phenanthrene from growth media was observed and attributed to the degradation of the chemical by the isolate, as the contribution of P. vittata in phenanthrene removal was negligible. The present results demonstrated the versatile arsenate-reducing and PAH-degrading bacteria can effectively enhance arsenic uptake and translocation by P. vittata and remove phenanthrene. [ABSTRACT FROM AUTHOR]

Hyperaccumulator biomass harvested after heavy-metal phytoremediation must be considered as hazardous waste that should be contained or treated appropriately before disposal or reuse. As a potential method to detoxify the biomass and to convert this material to a suitable bio-energy resource, the hydrothermal upgrading process was applied to remove heavy metals and upgrading crude bio-oil from Pteris vittata stems and leaves harvest. By using univariate experiment method, parameters such as material granularity, temperature, liquid/solid (L/S, mL/g), pressure, duration and catalysts were examined for their effect on the removal efficiency of heavy metals and upgrading efficiency of crude bio-oil. A heavy metals removal efficiency of >99% and crude bio-oil upgrading efficiency of 83% were attained with a 200 mesh (75 α/4m) granularity, L/S 40:1 and 23 MPa at 380 °C in the presence of 0.1 mol/L K 2 CO 3 for 30 min. GC•MS analysis results show that the resulting bio-oil mainly consists of benzene 11%, ketone 42%, alcohols 14%, alkene 15% and ester 11%, etc., and the relative molecular weight distribution lies in 94•282, carbon number distribution lies in 6•18, calorific value is 32 MJ/kg. [ABSTRACT FROM AUTHOR]

A work undertaken by pot and field experiments to assess the suitability of poplars and fernsfor thein-situ,phytoextraction, of a dumping sitewithresidues from the roasting process of arseno-pyrite is reported. The main characteristic of this site is the high content of both the As metalloid and heavy metals (e.g., Al, Fe, Cu, Co, Cr, Pb). Two poplar clones(Populus deltoides‘Dvina’ andPopulus x canadensis‘Orion’) andPteris vittata(Chinese brake fern) were planted in the contaminated soil bothex situin pots andin situ.Plant survival, As accumulation in plant tissues, leaf content of pigments, soluble proteins, activity of catalase and SH-groups in both roots and leaves were evaluated during a 24-month study period.Both poplar and fern plants exhibited an increase in the activity of catalase and SH groupcontentswhen grown in the presence of pyrite ashes. The results showed that the co-planting system (arsenic-hyperaccumulator fernPteris vittataandPopulusclones) was suitable for phytoextraction of multi-contaminated dumping sites. Agronomic measures such as irrigation, soil tillage and amendments also seem to be necessary for the successful establishment of poplar trees and ferns in contaminated soils in order to enhance plant growth through the improvement of soil conditions. [ABSTRACT FROM AUTHOR]

Abstract: Pteris vittata, the first known arsenic hyperaccumulating plant, can accumulate very high concentration arsenic in its aboveground tissues, while low in roots. Previous studies have suggested that arsenic vacuole compartmentalization may play an important role in the arsenic-hyperaccumulation in P. vittata, but the mechanism(s) of arsenic transport to vacuole are largely unknown. We obtained tonoplast isolated from fronds of P. vittata sporophyte grown under minus and 1mM arsenate for 3weeks by iodixanol step gradient centrifugation method, and then used TMPP protein labeling technology followed by liquid chromatography—a linear ion trap-Orbitrap hybrid mass spectrometer analysis for the quantitative detection of proteins. And we designed and used an “artificial” database for database searching. In total, 56 tonoplast proteins were identified; more than 70% of them were transport proteins. Under arsenate treatment, one TDT transporter protein, a member of the TerC family and a PDR-like protein were upregulated differentially. While V-ATPase subunits c, E, and G, and V-PPase, were downregulated. Additionally, the identified tonoplast proteins in our present study provide an informative basis for arsenic carriers or channels and help to clarify the regulation of tonoplast arsenic transport processes in P. vittata. Biological significance: Vacuole compartmentalization is crucial to As hyperaccumulator P. vittata, while there is limited known arsenic transport proteins involved in vacuole compartmentalization. In this paper, we obtained tonoplast of P. vittata fronds by iodixanol step gradient centrifugation method and then used TMPP protein labeling proteome technology for the quantitative detection of fronds tonoplast proteins. Our findings are the first challenge to the tonoplast proteins data mining of P. vittata which provide an informative basis for As carriers or channels. The proteomic approach in our study is suited for detecting alterations tonoplast protein and help to clarify the regulation of tonoplast transport processes. This article is part of a Special Issue entitled: Proteomics of non-model organisms. [Copyright &y& Elsevier]

Constructed wetlands are an attractive choice for removing arsenic (As) within water resources used for drinking water production. The role of substrate and vegetation in As removal processes is still poorly understood. In this study, gravel, zeolite (microporous aluminosilicate mineral), ceramsite (lightweight expanded clay aggregate) and manganese sand were tested as prospective substrates while aquaticJuncus effuses(Soft Rush or Common Rush) and terrestrialPteris vittataL. (Chinese Ladder Brake; known as As hyperaccumulator) were tested as potential wetland plants. Indoor batch adsorption experiments combined with outdoor column experiments were conducted to assess the As removal performances and process mechanisms. Batch adsorption results indicated that manganese sand had the maximum As(V) adsorption rate of 4.55 h−1and an adsorption capacity of 42.37 μg/g compared to the other three aggregates. The adsorption process followed the pseudo-first-order kinetic model and Freundlich isotherm equations better than other kinetic and isotherm models. Film-diffusion was the rate-limiting step. Mean adsorption energy calculation results indicated that chemical forces, particle diffusion and physical processes dominated As adsorption to manganese sand, zeolite and gravel, respectively. During the whole running period, manganese sand-packed wetland filters were associated with constantly 90% higher As(V) reduction of approximate 500 μg/L influent loads regardless if planted or not. The presence ofP. vittatacontributed to no more than 13.5% of the total As removal. In contrast,J. effuseswas associated with a 24% As removal efficiency. [ABSTRACT FROM PUBLISHER]

The discovery of the arsenic hyperaccumulator,Pteris vittata(Chinese brake fern), has contributed to the promotion of its application as a means of phytoremediation for arsenic removal from contaminated soils and water. Understanding the mechanisms involved in arsenic tolerance and accumulation of this plant provides valuable tools to improve the phytoremediation efficiency. In this review, the current knowledge about the physiological and molecular mechanisms of arsenic tolerance and accumulation inP. vittatais summarized, and an attempt has been made to clarify some of the unresolved questions related to these mechanisms. In addition, the capacity ofP. vittatafor remediation of arsenic-contaminated soils is evaluated under field conditions for the first time, and possible solutions to improve the remediation capacity ofPteris vittataare also discussed. [ABSTRACT FROM AUTHOR]

Cadmium uptake, tissue localization and structural changes induced at cellular level are essential to understand Cd tolerance in plants. In this study we have exposed plants of Pteris vittata to different concentrations of CdCl (0, 30, 60, 100 μM) to evaluate the tolerance of the fern to cadmium. Cadmium content determination and its histochemical localization showed that P. vittata not only takes up, but also transports and accumulates cadmium in the aboveground tissues, delocalizing it mainly in the less bioactive tissues of the frond, the trichomes and the scales. Cadmium tolerance in P. vittata was strictly related to morphogenic response induced by the metal itself in the root system. Adaptive response regarded changes of the root apex size, the developmental pattern of root hairs, the differentiation of xylem elements and endodermal suberin lamellae. All the considered parameters suggest that, in our experimental conditions, 60 μM of Cd may represent the highest concentration that P. vittata can tolerate; indeed this Cd level even improves the absorbance features of the root and allows good transport and accumulation of the metal in the fronds. The results of this study can provide useful information for phytoremediation strategies of soils contaminated by Cd, exploiting the established ability of P. vittata to transport, delocalize in the aboveground biomass and accumulate polluting metals. [ABSTRACT FROM AUTHOR]

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. [Copyright &y& Elsevier]

Pteris vittata is known as an arsenic hyperaccumulator, but there is little information about its tolerance to cadmium and on its ability to accumulate this heavy metal. Our aim was to analyse the accumulation capacity, oxidative stress and antioxidant response of this fern after cadmium treatments. Cadmium content, main markers of oxidative stress and antioxidant response were detected in leaves of plants grown in hydroponics for both short- (5 days) and long- (15 days) term exposure to 0 (control) 60 and 100 μM CdCl. In leaves, the concentration of cadmium and oxidative stress were parallel with the increase of cadmium exposure. In the short-term exposure, antioxidant response was sufficient to contrast cadmium phytotoxicity only in 60 μM cadmium-treated plants. In the long-term exposure all treated plants, in spite of the increase in activity of some peroxide-scavenging enzymes, showed a significant increase in oxidative damage. As in the long-term stress markers were comparable in all treated plants, with no clear correlation with hydrogen peroxide content, at least part of cadmium-induced oxidative injury seems not mediated by HO. Based on our studies, P. vittata, able to uptake relatively high concentrations of cadmium, is only partially tolerant to this heavy metal. [ABSTRACT FROM AUTHOR]