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Sample records for acid plant tail

  1. Evolution of plant colonization in acid and alkaline mine tailing ponds after amendments and microorganisms application

    NASA Astrophysics Data System (ADS)

    Acosta, Jose Alberto; Faz, Ángel; Kabas, Sebla; Zornoza, Raúl; Martínez-Martínez, Silvia

    2014-05-01

    Intense mining activities in the past were carried out in Cartagena-La Unión mining district, SE Spain, and caused excessive accumulation of toxic metals in tailing ponds which poses a high environmental and ecological risk. One of the remediation options gaining considerable interest in recent years is the in situ immobilization of metals. A corresponding reduction in the plant-available metal fraction allows re-vegetation and ecosystem restoration of the heavily contaminated sites. In addition, the use of microorganisms to improve the soil condition is a new tool used to increase spontaneous plant colonization. The aim of this research was to assess the effect of amendments (pig manure, sewage sludge, and lime) and microorganisms on plant cover establishment, as a consequence of metal immobilization and the improvement of soil properties. The study was carried out in two mine ponds (acid and alkaline). Twenty seven square field plots, each one consisting of 4 m2, were located in each pond. Four different doses of microorganism (0 ml, 20 ml, 100 ml and 200 ml of microorganism solution in each plot) and one dose of pig manure (5 kg per plot), sewage sludge (4 kg per plot) and lime (22 kg per plot) were used. Organic amendment doses were calculated according to European nitrogen legislations, and lime dose was calculated according with the potential acid production through total sulphur oxidation. Three replicates of each treatment (organic amendment + lime + microorganism dose 0, 1, 2, or 3) and control soil (with no amendments) were carried out. Plots were left to the semi-arid climate conditions after the addition of amendments to simulate real potential applications of the results. Identification of plant species and biodiversity was determined on each plot, after 2, 4, 6 and 8 months of amendment addition. The results showed that, in those plots without application of microorganism, 8 months after applications the number of species and individuals of each

  2. Response of Key Soil Parameters During Compost-Assisted Phytostabilization in Extremely Acidic Tailings: Effect of Plant Species

    PubMed Central

    Solís-Dominguez, Fernando A.; White, Scott A.; Hutter, Travis Borrillo; Amistadi, Mary Kay; Root, Robert A.; Chorover, Jon; Maier, Raina M.

    2012-01-01

    Phytostabilization of mine tailings acts to mitigate both eolian dispersion and water erosion events which can disseminate barren tailings over large distances. This technology uses plants to establish a vegetative cover to permanently immobilize contaminants in the rooting zone, often requiring addition of an amendment to assist plant growth. Here we report the results of a greenhouse study that evaluated the ability of six native plant species to grow in extremely acidic (pH ~ 2.5) metalliferous (As, Pb, Zn: 2000–3000 mg kg−1) mine tailings from Iron King Mine Humboldt Smelter Superfund site when amended with a range of compost concentrations. Results revealed that three of the six plant species tested (buffalo grass, mesquite, and catclaw acacia) are good candidates for phytostabilization at an optimum level of 15% compost (w/w) amendment showing good growth and minimal shoot accumulation of metal(loid)s. A fourth candidate, quailbush, also met all criteria except for exceeding the domestic animal toxicity limit for shoot accumulation of zinc. A key finding of this study was that the plant species that grew most successfully on these tailings significantly influenced key tailings parameters; direct correlations between plant biomass and both increased tailings pH and neutrophilic heterotrophic bacterial counts were observed. We also observed decreased iron oxidizer counts and decreased bioavailability of metal(loid)s mainly as a result of compost amendment. Taken together, these results suggest that the phytostabilization process reduced tailings toxicity as well as the potential for metal(loid) mobilization. This study provides practical information on plant and tailings characteristics that is critically needed for successful implementation of assisted phytostabilization on acidic, metalliferous mine tailings sites. PMID:22191663

  3. Response of key soil parameters during compost-assisted phytostabilization in extremely acidic tailings: effect of plant species.

    PubMed

    Solís-Dominguez, Fernando A; White, Scott A; Hutter, Travis Borrillo; Amistadi, Mary Kay; Root, Robert A; Chorover, Jon; Maier, Raina M

    2012-01-17

    Phytostabilization of mine tailings acts to mitigate both eolian dispersion and water erosion events which can disseminate barren tailings over large distances. This technology uses plants to establish a vegetative cover to permanently immobilize contaminants in the rooting zone, often requiring addition of an amendment to assist plant growth. Here we report the results of a greenhouse study that evaluated the ability of six native plant species to grow in extremely acidic (pH ∼ 2.5) metalliferous (As, Pb, Zn: 2000-3000 mg kg(-1)) mine tailings from Iron King Mine Humboldt Smelter Superfund site when amended with a range of compost concentrations. Results revealed that three of the six plant species tested (buffalo grass, mesquite, and catclaw acacia) are good candidates for phytostabilization at an optimum level of 15% compost (w/w) amendment showing good growth and minimal shoot accumulation of metal(loid)s. A fourth candidate, quailbush, also met all criteria except for exceeding the domestic animal toxicity limit for shoot accumulation of zinc. A key finding of this study was that the plant species that grew most successfully on these tailings significantly influenced key tailings parameters; direct correlations between plant biomass and both increased tailings pH and neutrophilic heterotrophic bacterial counts were observed. We also observed decreased iron oxidizer counts and decreased bioavailability of metal(loid)s mainly as a result of compost amendment. Taken together, these results suggest that the phytostabilization process reduced tailings toxicity as well as the potential for metal(loid) mobilization. This study provides practical information on plant and tailings characteristics that is critically needed for successful implementation of assisted phytostabilization on acidic, metalliferous mine tailings sites.

  4. Improvement on the thermal stability and activity of plant cytosolic ascorbate peroxidase 1 by tailing hyper-acidic fusion partners.

    PubMed

    Zhang, Mengru; Gong, Ming; Yang, Yumei; Li, Xujuan; Wang, Haibo; Zou, Zhurong

    2015-04-01

    Cytosolic ascorbate peroxidase 1 (APX1) plays a crucial role in regulating the level of plant cellular reactive oxygen species and its thermolability is proposed to cause plant heat-susceptibility. Herein, several hyper-acidic fusion partners, such as the C-terminal peptide tails, were evaluated for their effects on the thermal stability and activity of APX1 from Jatropha curcas and Arabidopsis. The hyper-acidic fusion partners efficiently improved the thermostability and prevented thermal inactivation of APX1 in both plant species with an elevated heat tolerance of at least 2 °C. These hyper-acidified thermostable APX1 fusion variants are of considerable biotechnological potential and can provide a new route to enhance the heat tolerance of plant species especially of inherent thermo-sensitivity.

  5. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    PubMed Central

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p < 0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  6. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    PubMed

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  7. Plant Growth-Promoting Bacteria for Phytostabilization of Mine Tailings

    SciTech Connect

    Grandlic, C.J.; Mendez, M.O.; Chorover, J.; Machado, B.; Maier, R.M.

    2009-05-19

    Eolian dispersion of mine tailings in arid and semiarid environments is an emerging global issue for which economical remediation alternatives are needed. Phytostabilization, the revegetation of these sites with native plants, is one such alternative. Revegetation often requires the addition of bulky amendments such as compost which greatly increases cost. We report the use of plant growth-promoting bacteria (PGPB) to enhance the revegetation of mine tailings and minimize the need for compost amendment. Twenty promising PGPB isolates were used as seed inoculants in a series of greenhouse studies to examine revegetation of an extremely acidic, high metal content tailings sample previously shown to require 15% compost amendment for normal plant growth. Several isolates significantly enhanced growth of two native species, quailbush and buffalo grass, in tailings. In this study, PGPB/compost outcomes were plant specific; for quailbush, PGPB were most effective in combination with 10% compost addition while for buffalo grass, PGPB enhanced growth in the complete absence of compost. Results indicate that selected PGPB can improve plant establishment and reduce the need for compost amendment. Further, PGPB activities necessary for aiding plant growth in mine tailings likely include tolerance to acidic pH and metals.

  8. Native plant restoration of biosolids-amended copper mine tailings

    SciTech Connect

    Kramer, P.A.; Zabowski, D.; Everett, R.L.; Scherer, G.

    1998-12-31

    Copper mine tailings are difficult to revegetate due to nutrient deficiencies, high levels of acidity, and potential metal toxicities. An amendment of biosolids could ameliorate these harsh growing conditions through the addition of available nutrients, improvement of physical soil properties (e.g., increased water holding capacity), and possible lowering of toxic metal availability through complexation with organic matter. A study was conducted on mine tailings at Holden, WA to evaluate the effect of an amendment of biosolids on the survival and growth of five native plant species (Sitka alder, big leaf maple, fireweed, w. yarrow, and pearly everlasting). Plots were established in tailings, gravel over tailings (G/T), and biosolids plus gravel over tailings. Each of the native plant species, except maple, had their highest survival in the biosolids-amended plot with 3 species at 100% survival. The biosolids amendment was shown to improve the growth of all species except maple. Fireweed produced 62 times more biomass in the biosolids-amended plot compared to the unamended plot (G/T). Plant analysis revealed a dramatic increase in nutrient content with the amendment of biosolids. Biosolids improved the survival, growth, and nutritional status of native plant species on the copper mine tailings.

  9. Assessment of Phytostabilization Success in Metalliferous Acid Mine Tailings

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Root, R. A.; Hammond, C.; Amistadi, M. K.; Maier, R. M.; Chorover, J.

    2014-12-01

    Legacy mine tailings are a significant source of metal(loid)s due to wind and water erosion, especially in the arid southwest, and exposure to fugative dusts presents a health risk to surrounding populations. Compost assisted phytostabilization has been implemented to reduce off site emissions at the Iron King Mine U.S. Superfund Site in central Arizona, concurrent with a greenhouse mesocosm study for detailed study of subsurface mechanisms. Quantification of plant available toxic metal(loid)s in the amended tailings was accessed with a targeted single extraction of diethylenetriaminepentaactic acid (DTPA). Greenhouse mesocosms (1m dia, 0.4 m deep), run in triplicate, mimicked field treatments with: i) tailings only control (TO), ii) tailings plus 15 wt% compost (TC), iii) TC + quailbush seeds (TCA), and iv) TC + buffalo grass seeds (TCB). Core samples collected at 3-month intervals for 1 year were dissected by depth (10 cm each) for analysis. DTPA results indicated that compost treated samples decreased plant availability of Al, As, Cd, Cu, Fe, and Pb but increased Mn and Zn compared with TO. TCB decreased plant available metal(loid)s at all depths, whereas TCA plant available Al, As, Cd, Cu, Fe, Mn and Zn increased in the deeper 20-30cm and 30-40 cm relative to TCB. Samples from the greenhouse were compared to tailings from both the field site and tailings impacted soils used to grow vegetables. Mineral transformations and metal complexation, in the pre- and post-extracted tailings were analyzed by synchrotron transmission XRD and FTIR spectroscopy. The temporal change in plant available metal(loid)s in response to phytostabilization indicates mineralogical alteration that improves soil quality by reducing plant available metal(loid)s. These results will aid in the understanding and efficacy of phytostabilization as a means of remediating and reducing toxicity on mine tailings as well as providing information on health risk management in the region.

  10. Effects of plant growth-promoting bacteria isolated from copper tailings on plants in sterilized and non-sterilized tailings.

    PubMed

    Liu, Weiqiu; Yang, Chao; Shi, Si; Shu, Wensheng

    2014-02-01

    Ten strains of Cu-tolerant bacteria with potential plant growth-promoting ability were isolated by selecting strains with the ability to use 1-aminocyclopropane-1-carboxylate as a sole nitrogen source (designated ACC-B) or fix nitrogen (designated FLN-B) originating from the rhizosphere of plants growing on copper tailings. All 10 strains proved to have intrinsic ability to produce indole acetic acid and siderophores, and most of them could mobilize insoluble phosphate. In addition, a greenhouse study showed that ACC-B, FLN-B and a mixture of both had similar, potent ability to stimulate growth of Pennisetum purpureum, Medicago sativa and Oenothera erythrosepala plants grown on sterilized tailings. For instance, above-ground biomass of P. purpureum was 278-357% greater after 60d growth on sterilized tailings in their presence. They could also significantly promote the growth of the plants grown on non-sterilized tailings, though the growth-promoting effects were much weaker. So, strategies for using of the plant growth-promoting bacteria in the practice of phytoremediation deserve further studies to get higher growth-promoting efficiency.

  11. Plant and soil reactions to nickel ore processed tailings

    SciTech Connect

    Sheets, P.J.; Volk, V.V.; Gardner, E.H.

    1982-07-01

    Greenhouse and laboratory experiments were conducted to determine the effect that tailings, produced during the processing of nickeliferous laterite ores by a proposed U.S. Bureau of Mines Process, would have on plant growth and soil properties. The tailings contained soluble salts (7.6 mmhos/cm), NH/sub 4/-N (877 ..mu..g/g), Ni (0.28%), Mn (82 ..mu..g/g DTPA-extractable), Cr (0.44%), P (2 and 6 ..mu..g/g acid F- and NaHCO/sub 3/-extractable, respectively), and Ca and Mg (1.0 and 20.7 meq/100 g NH/sub 4/Ac-extractable, respectively). Water leaching decreased the NH/sub 4/-N concentration to 53 ..mu..g/g and the EC to 0.4 mmhos/cm by removal of (NH/sub 4/)/sub 2/SO/sub 4/ and MgSO/sub 4/ salts. Tall fescue (Festuca arundinacea Schreb.) was grown on Eightlar clay soil (skeletal, serpentinitic, mesic Typic Xerochrept) amended with 0, 223, 446, and 669 g tailings/kg soil and pure, unleached tailings for 32 weeks in the greenhouse. Seedling establishment of plants grown on soil amended at the highest tailings rate and the pure tailings was initially slow, but plants grown on soil amended at lower rates established readily and grew well. Plant P was <0.24%, while plant Ca concentrations were <0.45% throughout the growth period even though Ca(H/sub 2/PO/sub 2/)/sub 2/ and gypsum had been added. Ammonium acetate-extractable Ca at the end of the growth period was <5.0 meq/100 g on all amended soils.The Mn, Ni, and Cr concentrations of plants grown on treated soils were within normal ranges, although soil-analysis values were higher than commonly found. It is recommended that the tailings be washed to reduce NH/sub 4/-N and soluble salts prior to revegetation, and that native soil be added to the surface to reduce crusting.

  12. Tiger Tail Distillery alcohol plant starts up

    SciTech Connect

    Not Available

    1980-11-05

    Tiger Tail Distillery plans to start construction in Jan. 1981 of an $89.9 million ethanol plant that would produce 50 million gal/yr of alcohol from 19 million bushels of corn. A $66.8 million loan guarantee from the U.S. Farmers Home Administration will aid the construction of the plant, which will be located on the Mississippi River west of Dyersburg, Tenn. The plant is scheduled for completion eight months after the start of construction. The production and marketing of the alcohol would cost an estimated $1.80/gal, and the cost of barging the alcohol to New Orleans and Memphis would be $0.01/gal and $0.0025/gal, respectively.

  13. Geochemical modeling of cyanide in tailing dam gold processing plant

    NASA Astrophysics Data System (ADS)

    Khodadadi, Ahmad; Monjezi, M.; Mehrpouya, H.; Dehghani, H.

    2009-09-01

    This research is aimed at investigating possible neutralization of cyanide in tailing dam of Muteh gold processing plant in Isfahan, Iran at various conditions such as pH and temperature using USEPA Visual MINTEQ geochemical model simulation. The model is based on geochemical equilibrium which uses the simultaneous solution of the non-linear mass action expressions and linear mass balance relationships to formulate and solve the multiple-component chemical equilibrium problems. In this study the concentration of aqueous species in tailing dam as an aqueous, solid and gaseous were used as input in the model. Temperature and pH variation were simulated. The results of the model indicated that cyanide may be complexes in 10 < pH < 5. In other pH values complexation is not important. The results also indicated that cyanide reduction mechanism in acidic pH and temperature above 30°C is due to cyanide acid formation which is vaporized.

  14. Phytostabilization of gold mine tailings, New Zealand. Part 1: Plant establishment in alkaline saline substrate.

    PubMed

    Mains, D; Craw, D; Rufaut, C G; Smith, C M S

    2006-01-01

    Tailings from the Macraes mine, southern New Zealand, are prone to wind erosion. Use of a vegetation cover for physical stabilization is one potential solution to this environmental problem. This study used field trials contained in lysimeters to 1), test the ability of different plant species to grow in un/amended tailings and 2), provide background information on the nutrient and chemical content of waters in tailings. Barley (Hordeum vulgare), blue lupin (Lupinus angustifolius), and rye corn (Secale cereale) were trialed, using Superphosphate fertilizer and sewage sludge as amendments. Rye corn grew well in fertilizer-amended tailings, but poorly in unamended tailings; barley growth was similar in amended and unamended tailings; blue lupins grew poorly overall The tailings had alkaline pH (7-8.5) and water rapidly (< 1 mo) interacted with the tailings to become strongly saline. Minor acid generation was neutralized by calcite, with associated release of calcium and carbonate ions. Leachate waters were supersaturated with respect to calcite and dolomite. Dissolved sodium concentrations were up to 1000 mg L(-1), but elevated Ca2+ calcium and Mg2+ ensured that sodicity was lower than plant-toxic levels. Rye corn is a potentially useful plant for rapid phytostabilization of tailings, with only minor phosphate amendment required.

  15. MIDDLE GORGE POWER PLANT, OWENS RIVER STREAM FLOWING OVER TAIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MIDDLE GORGE POWER PLANT, OWENS RIVER STREAM FLOWING OVER TAIL RACE OF POWER PLANT AND PENSTOCK HEADGATE TO LOWER GORGE CONTROL PLANT. A MINIMAL FLOW OF RIVER WATER IS REQUIRED TO MAINTAIN FISH LIFE - Los Angeles Aqueduct, Middle Gorge Power Plant, Los Angeles, Los Angeles County, CA

  16. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  17. Arsenic and heavy metals in native plants at tailings impoundments in Queretaro, Mexico

    NASA Astrophysics Data System (ADS)

    Santos-Jallath, José; Castro-Rodríguez, Alejandrina; Huezo-Casillas, José; Torres-Bustillos, Luis

    Ten native plants species that grow in three tailings dams from Ag, Pb, Cu and Zn mine in Queretaro, Mexico were studied. Total concentrations in tailings were 183-14,660 mg/kg As, 45-308 mg/kg Cd, 327-1754 mg/kg Pb, 149-459 mg/kg Cu and 448-505 mg/kg Zn. In the three tailings dams, the solubility of these elements is low. Tailings in dam 1 are acid generating while tailings in dams 2 and 3 are not acid-generating potential. Plants species that accumulate arsenic and heavy metals was identified; Nicotina glauca generally presented the highest concentrations (92 mg/kg As, 106 mg/kg Cd, 189 mg/kg Pb, 95 mg/kg Cu and 1985 mg/kg Zn). Other species that accumulate these elements are Flaveria pubescens, Tecoma stans, Prosopis Sp, Casuarina Sp and Maurandia antirrhiniflora. Two species were found that accumulates a large amount of metals in the root, Cenchrus ciliaris and Opuntia lasiacantha. Concentrations in soils in which plants grow were 488-5990 mg/kg As, 5-129 mg/kg Cd, 169-3638 mg/kg Pb, 159-1254 mg/kg Cu and 1431-13,488 mg/kg Zn. The Accumulation Factor (AF) determined for plants was less than 1, with exception of N. glauca for Cd. The correlation between arsenic and heavy metals found in soils and plants was low. Knowledge of plant characteristics allows it use in planning the reforestation of tailings dams in controlled manner. This will reduce the risk of potentially toxic elements are integrated into the food chain of animal species.

  18. OVERVIEW OF CYANIDE PLANT REMAINS, TAILINGS PILES, PARKING LOT, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW OF CYANIDE PLANT REMAINS, TAILINGS PILES, PARKING LOT, AND MINE MANAGER'S HOME, LOOKING SOUTH SOUTHEAST. RIGHT, TAILINGS PILES ARE AT CENTER WITH CYANIDE PLANT FOUNDATIONS TO THE LEFT OF THE PILES. PARKING LOT IS AT UPPER LEFT. THE AREA BETWEEN THE COLLAPSED TANK AT CENTER LEFT AND THE REMAINS OF THE MANAGER'S HOUSE AT LOWER RIGHT IS A TAILINGS HOLDING AREA. TAILINGS FROM THE MILL WERE HELD HERE. THE LARGE SETTLING TANKS WERE CHARGED FROM THIS HOLDING AREA BY A TRAM ON RAILS AND BY A SLUICEWAY SEEN AS THE DARK SPOT ON THE CENTER LEFT EDGE OF THE FRAME. AFTER THE TAILINGS WERE LEACHED, THEY WERE DEPOSITED ON THE LARGE WASTE PILE AT CENTER RIGHT. THE TANK AT CENTER RIGHT EDGE IS WHERE THE WATER PIPELINE ENTERED THE WORKS. A STRAIGHT LINE OF POSTS IN THE GROUND GO ACROSS THE CENTER FROM LEFT TO RIGHT, WHICH ORIGINALLY SUSPENDED THE WATER PIPELINE GOING FROM THE WATER HOLDING TANK AT RIGHT UP TO THE SECONDARY WATER TANKS ABOVE THE MILL. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  19. Plant selection for dewatering and reclamation of tailings

    SciTech Connect

    Silva, M.J.; Naeth, M.A.; Biggar, K.W.; Chanasyk, D.S.; Sego, D.C.

    1998-12-31

    A two-phase greenhouse experiment was conducted to identify the most suitable species for dewatering and reclamation of Composite Tailings (CT) from Alberta oil sands operated by Syncrude Canada Ltd. and Copper Mine Tailings (CMT) from the Kennecott site in Utah. A total of 15 and 9 plant species were selected for testing in CT and CMT, respectively. In Phase 1, distilled water was added weekly to simulate local precipitation. The initial solids content were 80% and 76% and the electrical conductivities were 1.1 dS/m and 3.2 dS/m for CT and CMT, respectively. All plants survived after a ten-week period. In Phase 2 only process water was added weekly to provide a worst case scenario of no precipitation and water recharge due only to process water being released from within the tailings. The initial solids contents were 65% and 76% for CT and CMT, respectively. Surface (0--3 in.) salinity increased dramatically due to the application of process water only; at the end of Phase 2 it had reached toxic levels of approximately 18.9 dS/m and 35.0 dS/m in CT and CMT, respectively. Many plants showed signs of stress due to the high salinity level. The plants which performed the best under both phases in Composite Tailings were creeping foxtail (Alopecurus arundinaceus), reed canarygrass (Phalaris arundinacea), Altai wildrye (Elymus angustus), and red top (Agrostis stolonifera); and in Copper Mine Tailings were Altai wildrye, smooth bromegrass (Bromus inermis) and creeping foxtail.

  20. Hyaluronic acid synthesis is required for zebrafish tail fin regeneration

    PubMed Central

    Ouyang, Xiaohu; Panetta, Nicholas J.; Talbott, Maya D.; Payumo, Alexander Y.; Halluin, Caroline; Longaker, Michael T.

    2017-01-01

    Using genome-wide transcriptional profiling and whole-mount expression analyses of zebrafish larvae, we have identified hyaluronan synthase 3 (has3) as an upregulated gene during caudal fin regeneration. has3 expression is induced in the wound epithelium within hours after tail amputation, and its onset and maintenance requires fibroblast growth factor, phosphoinositide 3-kinase, and transforming growth factor-ß signaling. Inhibition of hyaluronic acid (HA) synthesis by the small molecule 4-methylumbelliferone (4-MU) impairs tail regeneration in zebrafish larvae by preventing injury-induced cell proliferation. In addition, 4-MU reduces the expression of genes associated with wound epithelium and blastema function. Treatment with glycogen synthase kinase 3 inhibitors rescues 4-MU-induced defects in cell proliferation and tail regeneration, while restoring a subset of wound epithelium and blastema markers. Our findings demonstrate a role for HA biosynthesis in zebrafish tail regeneration and delineate its epistatic relationships with other regenerative processes. PMID:28207787

  1. Phytostabilization of mine tailings using compost-assisted direct planting: Translating greenhouse results to the field.

    PubMed

    Gil-Loaiza, Juliana; White, Scott A; Root, Robert A; Solís-Dominguez, Fernando A; Hammond, Corin M; Chorover, Jon; Maier, Raina M

    2016-09-15

    Standard practice in reclamation of mine tailings is the emplacement of a 15 to 90cm soil/gravel/rock cap which is then hydro-seeded. In this study we investigate compost-assisted direct planting phytostabilization technology as an alternative to standard cap and plant practices. In phytostabilization the goal is to establish a vegetative cap using native plants that stabilize metals in the root zone with little to no shoot accumulation. The study site is a barren 62-hectare tailings pile characterized by extremely acidic pH as well as lead, arsenic, and zinc each exceeding 2000mgkg(-1). The study objective is to evaluate whether successful greenhouse phytostabilization results are scalable to the field. In May 2010, a 0.27ha study area was established on the Iron King Mine and Humboldt Smelter Superfund (IKMHSS) site with six irrigated treatments; tailings amended with 10, 15, or 20% (w/w) compost seeded with a mix of native plants (buffalo grass, arizona fescue, quailbush, mountain mahogany, mesquite, and catclaw acacia) and controls including composted (15 and 20%) unseeded treatments and an uncomposted unseeded treatment. Canopy cover ranging from 21 to 61% developed after 41 months in the compost-amended planted treatments, a canopy cover similar to that found in the surrounding region. No plants grew on unamended tailings. Neutrophilic heterotrophic bacterial counts were 1.5 to 4 orders of magnitude higher after 41months in planted versus unamended control plots. Shoot tissue accumulation of various metal(loids) was at or below Domestic Animal Toxicity Limits, with some plant specific exceptions in treatments receiving less compost. Parameters including % canopy cover, neutrophilic heterotrophic bacteria counts, and shoot uptake of metal(loids) are promising criteria to use in evaluating reclamation success. In summary, compost amendment and seeding, guided by preliminary greenhouse studies, allowed plant establishment and sustained growth over 4years

  2. OVERVIEW OF CYANIDE PLANT FOUNDATIONS, ZINC BOXES, TANKS, AND TAILINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW OF CYANIDE PLANT FOUNDATIONS, ZINC BOXES, TANKS, AND TAILINGS PILES, LOOKING NORTHEAST. THE LOWER TRAM TERMINAL AND MILL SITE IS AT TOP CENTER IN THE DISTANCE. THE DARK SPOT JUST BELOW THE TRAM TERMINAL ARE REMAINS OF THE DEWATERING BUILDING. THE MAIN ACCESS ROAD IS AT UPPER LEFT. THE FOUNDATIONS AT CENTER SUPPORTED SIX 25 FT. OR GREATER DIAMETER SETTLING TANKS WHERE TAILINGS FROM THE MILL SETTLED IN A CYANIDE SOLUTION IN ORDER TO RECLAIM ANY GOLD CONTENT. THE PREGNANT SOLUTION WAS THEN RUN THROUGH THE ZINC BOXES ON THE GROUND AT CENTER RIGHT, WHERE ZINC SHAVINGS WERE INTRODUCED, CAUSING THE GOLD TO PRECIPITATE OUT OF THE CYANIDE SOLUTION, WHICH COULD BE USED AGAIN. THE FLAT AREA IN THE FOREGROUND WITH THE TANK AND TANK HOOPS IS THE FOOTPRINT OF A LARGE BUILDING WHERE THE PRECIPITATION AND FURTHER FILTERING AND FINAL CASTING TOOK PLACE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  3. Role of organic acids in promoting colloidal transport of mercury from mine tailings

    USGS Publications Warehouse

    Slowey, A.J.; Johnson, S.B.; Rytuba, J.J.; Brown, Gordon E.

    2005-01-01

    A number of factors affect the transport of dissolved and paniculate mercury (Hg) from inoperative Hg mines, including the presence of organic acids in the rooting zone of vegetated mine waste. We examined the role of the two most common organic acids in soils (oxalic and citric acid) on Hg transport from such waste by pumping a mixed organic acid solution (pH 5.7) at 1 mL/min through Hg mine tailings columns. For the two total organic acid concentrations investigated (20 ??M and 1 mM), particle-associated Hg was mobilized, with the onset of paniculate Hg transport occurring later for the lower organic acid concentration. Chemical analyses of column effluent indicate that 98 wt % of Hg mobilized from the column was paniculate. Hg speciation was determined using extended X-ray absorption fine structure spectroscopy and transmission electron microscopy, showing that HgS minerals are dominant in the mobilized particles. Hg adsorbed to colloids is another likely mode of transport due to the abundance of Fe-(oxyhydr)oxides, Fe-sulfides, alunite, and jarosite in the tailings to which Hg(II) adsorbs. Organic acids produced by plants are likely to enhance the transport of colloid-associated Hg from vegetated Hg mine tailings by dissolving cements to enable colloid release. ?? 2005 American Chemical Society.

  4. Plant fatty acid hydroxylase

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    2000-01-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  5. Bacillus pumilus ES4: candidate plant growth-promoting bacterium to enhance establishment of plants in mine tailings

    PubMed Central

    de-Bashan, Luz E.; Hernandez, Juan-Pablo; Bashan, Yoav; Maier, Raina

    2014-01-01

    Three plant growth-promoting bacteria (PGPB; Bacillus pumilus ES4, B. pumilus RIZO1, and Azospirillum brasilense Cd) were tested for their ability to enhance plant growth and development of the native Sonoran Desert shrub quailbush (Atriplex lentiformis) and for their effect on the native bacterial community in moderately acidic, high-metal content (AHMT) and in neutral, low metal content natural tailings (NLMT) in controlled greenhouse experiments. Inoculation of quailbush with all three PGPB significantly enhanced plant growth parameters, such as germination, root length, dry weight of shoots and roots, and root/shoot ratio in both types of tailings. The effect of inoculation on the indigenous bacterial community by the most successful PGPB Bacillus pumilus ES4 was evaluated by denaturating gradient gel electrophoresis (PCR-DGGE) fingerprinting and root colonization was followed by specific fluorescent in situ hybridization (FISH). Inoculation with this strain significantly changed the bacterial community over a period of 60 days. FISH analysis showed that the preferred site of colonization was the root tips and root elongation area. This study shows that inoculation of native perennial plants with PGPB can be used for developing technologies for phytostabilizing mine tailings. PMID:25009362

  6. Bacillus pumilus ES4: candidate plant growth-promoting bacterium to enhance establishment of plants in mine tailings.

    PubMed

    de-Bashan, Luz E; Hernandez, Juan-Pablo; Bashan, Yoav; Maier, Raina

    2010-12-01

    Three plant growth-promoting bacteria (PGPB; Bacillus pumilus ES4, B. pumilus RIZO1, and Azospirillum brasilense Cd) were tested for their ability to enhance plant growth and development of the native Sonoran Desert shrub quailbush (Atriplex lentiformis) and for their effect on the native bacterial community in moderately acidic, high-metal content (AHMT) and in neutral, low metal content natural tailings (NLMT) in controlled greenhouse experiments. Inoculation of quailbush with all three PGPB significantly enhanced plant growth parameters, such as germination, root length, dry weight of shoots and roots, and root/shoot ratio in both types of tailings. The effect of inoculation on the indigenous bacterial community by the most successful PGPB Bacillus pumilus ES4 was evaluated by denaturating gradient gel electrophoresis (PCR-DGGE) fingerprinting and root colonization was followed by specific fluorescent in situ hybridization (FISH). Inoculation with this strain significantly changed the bacterial community over a period of 60 days. FISH analysis showed that the preferred site of colonization was the root tips and root elongation area. This study shows that inoculation of native perennial plants with PGPB can be used for developing technologies for phytostabilizing mine tailings.

  7. Rapid plant-cover establishment on gold mine tailings in southern New Zealand: glasshouse screening trials.

    PubMed

    Schroeder, K; Rufaut, C G; Smith, C; Mains, D; Craw, D

    2005-01-01

    The use of a short-term vegetation cover to temporarily control the negative environmental effects of inactive tailings ponds is notfrequently practiced during operational mining, but could have some merit This article reports on a glasshouse trial designed to examine some of the issues associated with short-term vegetation: fast germination of a high proportion of seed, the ability of seedlings to survive in unamended substrates, and potentially toxic substrate. Five nonindigenous plant species were tested--barley (Hordeum vulgare), rye corn (Secale cereale), Italian ryegrass (Lolium multifiorum), red clover (Trifolium pratense), and lucerne (Medicago sativa)--in five different types of substrate: unamended tailings, tailings and fertilizer, tailings and greenwaste, biosolid-blend compost, and local topsoil. The nutrient and heavy metal status (As, Cu, Cd, Ni, Pb) of each substrate type was determined Plant species performance was monitored over 14 wk Substrate metal concentrations were low except for As, which was elevated in all substrate types. Plants in unamended tailings grew less vigorously than plants in tailings and compost or in topsoil. Plant performance in tailings and fertiliser was greatly suppressed following a high fertilization rate. Metal uptake in plants was highest for As (0.4-77 mg kg(-1) DW) and Cu (5.3-50.3 mg kg(-1) DW). Future field trials are necessary to authenticate findings, but barley and rye corn are promising species for a short-term tailings cover.

  8. Diversity of free-living nitrogen-fixing microorganisms in the rhizosphere and non-rhizosphere of pioneer plants growing on wastelands of copper mine tailings.

    PubMed

    Zhan, Jing; Sun, Qingye

    2012-03-20

    The composition of free-living nitrogen-fixing microbial communities in rhizosphere and non-rhizosphere of pioneer plants growing on wastelands of copper mine tailings was studied by the presence of nifH genes using Polymerase Chain Reaction-Denatured Gradient Gel Electrophoresis (PCR-DGGE) approach. Eleven rhizosphere tailing samples and nine non-rhizosphere tailing samples from six plant communities were collected from two wastelands with different discarded periods. The nested PCR method was used to amplify the nifH genes from environmental DNA extracted from tailing samples. Twenty-two of 37 nifH gene sequences retrieved from DGGE gels clustered in Proteobacteria (α-Proteobacteria and β-Proteobacteria) and 15 nifH gene sequences in Cyanobacteria. Most nifH gene fragments sequenced were closely related to uncultured bacteria and cyanobacteria and exhibited less than 90% nucleotide acid identity with bacteria in the database, suggesting that the nifH gene fragments detected in copper mine tailings may represent novel sequences of nitrogen-fixers. Our results indicated that the non-rhizosphere tailings generally presented higher diversity of nitrogen-fixers than rhizosphere tailings and the diversity of free-living nitrogen-fixers in tailing samples was mainly affected by the physico-chemical properties of the wastelands and plant species, especially the changes of nutrient and heavy metal contents caused by the colonization of plant community.

  9. Phytoremediation of Alberta oil sand tailings using native plants and fungal endophytes

    NASA Astrophysics Data System (ADS)

    Repas, T.; Germida, J.; Kaminskyj, S.

    2012-04-01

    Fungal endophytes colonize host plants without causing disease. Some endophytes confer plant tolerance to harsh environments. One such endophyte, Trichoderma harzianum strain TSTh20-1, was isolated from a plant growing on Athabasca oil sand tailings. Tailing sands are a high volume waste product from oil sand extraction that the industry is required to remediate. Tailing sands are low in organic carbon and mineral nutrients, and are hydrophobic due to residual polyaromatic hydrocarbons. Typically, tailing sands are remediated by planting young trees in large quantities of mulch plus mineral fertilizer, which is costly and labour intensive. In greenhouse trials, TSTh20-1 supports growth of tomato seedlings on tailing sands without fertilizer. The potential use of TSTh20-1 in combination with native grasses and forbs to remediate under field conditions is being assessed. Twenty-three commercially available plant species are being screened for seed germination and growth on tailing sands in the presence of TSTh20-1. The best candidates from this group will be used in greenhouse and small scale field trials. Potential mechanisms that contribute to endophyte-induced plant growth promotion, such as plant hormone production, stress tolerance, mineral solubilization, and uptake are also being assessed. As well, TSTh20-1 appears to be remarkably frugal in its nutrient requirements and the possibility that this attribute is characteristic of other plant-fungal endophytes from harsh environments is under study.

  10. 226Ra bioavailability to plants at the Urgeiriça uranium mill tailings site.

    PubMed

    Madruga, M J; Brogueira, A; Alberto, G; Cardoso, F

    2001-01-01

    Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeiriça mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment, some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides these plants, some shrubs (Cytisus spp.) are growing in some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings by quantifying the total and available fraction of radium in the tailings and to estimate its transfer to plants growing on the tailing piles. Plant and tailing samples were randomly collected and the activity concentration of 226Ra in plants (aerial part and roots) and tailings was measured by gamma-spectrometry. The exchangeable fraction of radium in tailings was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH = 7) or 1 mol dm-3 calcium chloride solutions. The results obtained for 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentrations in the tailings and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0 +/- 8.3 and 12.9 +/- 8.9, for the fraction of radium extracted from the tailings, using 1 mol dm-3 ammonium acetate or calcium chloride solutions, respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, at a 95% confidence level, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams.

  11. Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China.

    PubMed

    Xie, Pin; Hao, Xiuli; Herzberg, Martin; Luo, Yantao; Nies, Dietrich H; Wei, Gehong

    2015-01-01

    To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria (PGPB). It shows that: Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF (Cation Diffusion Facilitator), HupE/UreJ and CHR (chromate ion transporter) family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative CopA/CueO system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while ZntA transporter, assisted with putative CzcD, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid (IAA) secretion, indicating a potential in-site phytoremediation usage in the mining tailing regions of China.

  12. Role of mycorrhizal colonization in plant establishment on an alkaline gold mine tailing.

    PubMed

    Orłowska, Elzbieta; Orłowski, Dariusz; Mesjasz-Przybyłowicz, Jolanta; Turnau, Katarzyna

    2011-02-01

    The potential role of arbuscular mycorrhizal fungi (AMF) in the revegetation of an alkaline gold mine tailing was studied in Barberton, South Africa. The tailing, characterized by a slow spontaneous plant succession, is colonized by the shrub Dodonaea viscosa and the grasses, Andropogon eucomus and Imperata cylindrica, all colonized by AMF. The effectiveness of mycorrhizal colonization in grasses was tested under laboratory conditions using fungal isolates of various origins. Both grasses were highly mycorrhiza dependent, and the presence of mycorrhizal colonization significantly increased their biomass and survival rates. The fungi originating from the gold tailing were better adapted to the special conditions of the tailing than the control isolate. Although the total colonization rate found for native fungi was lower than for fungi from non-polluted sites, they were more vital and more effective in promoting plant growth. The results obtained might serve as a practical approach to the phytostabilization of alkaline gold tailings.

  13. Amino acid sequence of myoglobin from white-tailed deer (Odocoileus virginianus).

    PubMed

    Joseph, Poulson; Suman, Surendranath P; Li, Shuting; Fontaine, Michele; Steinke, Laurey

    2012-10-01

    Our objective was to determine the primary structure of white-tailed deer myoglobin (Mb). White-tailed deer Mb was isolated from cardiac muscles employing ammonium sulfate precipitation and gel-filtration chromatography. The amino acid sequence was determined by Edman degradation. Sequence analyses of intact Mb as well as tryptic- and cyanogen bromide-peptides yielded the complete primary structure of white-tailed deer Mb, which shared 100% similarity with red deer Mb. White-tailed deer Mb consists of 153 amino acid residues and shares more than 96% sequence similarity with myoglobins from meat-producing ruminants, such as cattle, buffalo, sheep, and goat. Similar to sheep and goat myoglobins, white-tailed deer Mb contains 12 histidine residues. Proximal (position 93) and distal (position 64) histidine residues responsible for maintaining the stability of heme are conserved in white-tailed deer Mb.

  14. Geochemical characterisation of seepage and drainage water quality from two sulphide mine tailings impoundments: Acid mine drainage versus neutral mine drainage

    USGS Publications Warehouse

    Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.

    2009-01-01

    Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.

  15. Methanogenic potential of tailings samples from oil sands extraction plants.

    PubMed

    Fedorak, Phillip M; Coy, Debora L; Salloum, Myrna J; Dudas, Marvin J

    2002-01-01

    Approximately 20% of Canada's oil supply now comes from the extraction of bitumen from the oil sands deposits in northeastern Alberta. The oil sands are strip-mined, and the bitumen is typically separated from sand and clays by an alkaline hot water extraction process. The rapidly expanding oil sands industry has millions of cubic metres of tailings for disposal and large areas of land to reclaim. There are estimates that the consolidation of the mature fine tails (MFT) in the settling ponds will take about 150 years. Some of the settling ponds are now evolving microbially produced methane, a greenhouse gas. To hasten consolidation, gypsum (CaSO4 x 2H2O) is added to MFT, yielding materials called consolidated or composite tailings (CT). Sulfate from the gypsum has the potential to stimulate sulfate-reducing bacteria (SRB) to out-compete methanogens, thereby stopping methanogenesis. This investigation examined three MFT and four CT samples from three oil sands extractions companies. Each was found to contain methanogens and SRB. Serum bottle microcosm studies showed sulfate in the CT samples stopped methane production. However, if the microcosms were amended with readily utilizable electron donors, the sulfate was consumed, and when it reached approximately 20 mg/L, methane production began. Some unamended microcosms were incubated for 372 days, with no methane production detected. This work showed that each MFT and CT sample has the potential to become methanogenic, but in the absence of exogenous electron donors, the added sulfate can inhibit methanogenesis for a long time.

  16. Geophysical delineation of acidity and salinity in the Central Manitoba gold mine tailings pile, Manitoba, Canada

    NASA Astrophysics Data System (ADS)

    Tycholiz, C.; Ferguson, I. J.; Sherriff, B. L.; Cordeiro, M.; Sri Ranjan, R.; Pérez-Flores, M. A.

    2016-08-01

    Surface electrical and electromagnetic geophysical methods can map enhanced electrical conductivity caused by acid mine drainage in mine tailings piles. In this case study, we investigate quantitative relationships between geophysical responses and the electrical conductivity, acidity and salinity of tailing samples at the Central Manitoba Mine tailings in Manitoba, Canada. Previous electromagnetic surveys at the site identified zones of enhanced conductivity that were hypothesized to be caused by acid mine drainage. In the present study, high-resolution EM31 and DC-resistivity measurements were made on a profile through a zone of enhanced conductivity and laboratory measurements of salinity and pH were made on saturation paste extracts from an array of tailing samples collected from the upper 2 m of tailings along the profile. Observed spatial correlation of pH and pore-fluid salinity in the tailings samples confirms that the enhanced conductivity in the Central Manitoba Mine tailings is due to acid mine drainage. Contoured cross-sections of the data indicate that the acid mine drainage is concentrated near the base of the oxidized zone in the thicker parts of the tailings pile. The zone of increased acidity extends to the surface on sloping margins causing an increase in apparent conductivity in shallow penetrating geophysical responses. The quantitative relationship between measured pH and salinity shows that the conductivity increase associated with the acid mine drainage is due only in part to conduction by ions produced from dissociation of sulfuric acid. Comparison of the observations with fluid conductivity estimates based on statistical relationships of pH and ion concentrations in water samples from across the tailings pile shows that Ca2 + and Mg2 + ions also make significant contributions to the conductivity at all values of pH and Cu2 +, Al3 + and Fe3 + ions make additional contributions at low pH. Variability in the measured conductivity at constant

  17. Phytobarriers: Plants capture particles containing potentially toxic elements originating from mine tailings in semiarid regions.

    PubMed

    Sánchez-López, Ariadna S; Carrillo-González, Rogelio; González-Chávez, Ma Del Carmen Angeles; Rosas-Saito, Greta Hanako; Vangronsveld, Jaco

    2015-10-01

    Retention of particles containing potentially toxic elements (PTEs) on plants that spontaneously colonize mine tailings was studied through comparison of washed and unwashed shoot samples. Zn, Pb, Cd, Cu, Ni, Co and Mn concentrations were determined in plant samples. Particles retained on leaves were examined by Scanning Electronic Microscopy and energy dispersive X-Ray analysis. Particles containing PTEs were detected on both washed and unwashed leaves. This indicates that the thorough washing procedure did not remove all the particles containing PTEs from the leaf surface, leading to an overestimation of the concentrations of PTEs in plant tissues. Particularly trichomes and fungal mycelium were retaining particles. The quantity and composition of particles varied among plant species and place of collection. It is obvious that plants growing on toxic mine tailings form a physical barrier against particle dispersion and hence limit the spread of PTEs by wind.

  18. Microbial Diversity and Metal Speciation Changes in Mine Tailings Following Compost-Assisted Direct Planting: A Four-Year Superfund Site Field Study

    NASA Astrophysics Data System (ADS)

    Maier, R. M.; Gil-Loaiza, J.; Honeker, L. K.; Hottenstein, J. D.; Valentin-Vargas, A.; Jennings, L. L.; Hammond, C.; Neilson, J. W.; Root, R. A.; Chorover, J.

    2014-12-01

    EPA estimates that future mine tailings remediation costs will exceed US $50 billion using present technologies based on constructing an inert or biological cap on the tailings. Both approaches require large amounts of capping materials that can be difficult and expensive to obtain especially for sites several thousand hectares in size. An alternative technology is direct planting into tailings. However, direct planting alone is not feasible for many legacy sites due to extreme acidity and high metal content which prevent plant germination and growth. Therefore the process must be "assisted" through the addition of amendments such as compost. Here we present results from the first four years of a field study at the Iron King Mine and Humboldt Smelter Superfund site demonstrating the feasibility of compost-assisted direct planting. Parameters measured during the field study included: canopy cover, pH, nutrient content, plant metal uptake, metal(loid) speciation, mineral analysis, microbiome analysis, and plant root-metal-microbe interactions. Integrated analysis of these parameters suggests that even in this "worst-case scenario" mine tailings site (pH 2.5; As and Pb each exceeding 2 g kg-1), we have created a sustainable system. In this system, phyto-catalyzed stabilization of inorganic contaminants in the root zone is driven by plant root exudates and the associated rhizosphere microbial community. The results of this research will be put into context of a larger topic- that of ecological engineering of mine tailings sites - a technique being proposed to prevent creation of acidic conditions and metal(loid) mobilization in the first place.

  19. Microbial Diversity and Metal Speciation Changes in Mine Tailings Following Compost-Assisted Direct Planting: A Four-Year Superfund Site Field Study

    NASA Astrophysics Data System (ADS)

    Maier, R. M.; Gil-Loaiza, J.; Honeker, L. K.; Hottenstein, J. D.; Valentin-Vargas, A.; Jennings, L. L.; Hammond, C.; Neilson, J. W.; Root, R. A.; Chorover, J.

    2015-12-01

    EPA estimates that future mine tailings remediation costs will exceed US $50 billion using present technologies based on constructing an inert or biological cap on the tailings. Both approaches require large amounts of capping materials that can be difficult and expensive to obtain especially for sites several thousand hectares in size. An alternative technology is direct planting into tailings. However, direct planting alone is not feasible for many legacy sites due to extreme acidity and high metal content which prevent plant germination and growth. Therefore the process must be "assisted" through the addition of amendments such as compost. Here we present results from the first four years of a field study at the Iron King Mine and Humboldt Smelter Superfund site demonstrating the feasibility of compost-assisted direct planting. Parameters measured during the field study included: canopy cover, pH, nutrient content, plant metal uptake, metal(loid) speciation, mineral analysis, microbiome analysis, and plant root-metal-microbe interactions. Integrated analysis of these parameters suggests that even in this "worst-case scenario" mine tailings site (pH 2.5; As and Pb each exceeding 2 g kg-1), we have created a sustainable system. In this system, phyto-catalyzed stabilization of inorganic contaminants in the root zone is driven by plant root exudates and the associated rhizosphere microbial community. The results of this research will be put into context of a larger topic- that of ecological engineering of mine tailings sites - a technique being proposed to prevent creation of acidic conditions and metal(loid) mobilization in the first place.

  20. Metal concentrations and mycorrhizal status of plants colonizing copper mine tailings: potential for revegetation.

    PubMed

    Chen, Baodong; Tang, Xiangyu; Zhu, Yongguan; Christie, Peter

    2005-05-01

    A field survey of metal concentrations and mycorrhizal status of plants growing on copper mine tailings was conducted in Anhui Province, China. Available phosphorus and organic matter in the tailings were very low. High concentrations of Pb, Zn, As and Cd as well as Cu were observed on some sites. The dominant plants growing on mine tailings belonged to the families Gramineae and Compositae, and the most widely distributed plant species were Imperata cylindrica, Cynodon dactylon and Paspalum distichum. Coreopsis drummondii also grew well on the arid sites but not on wet sites. Very low or zero arbuscular mycorrhizal (AM) fungal colonization was observed in most of the plants, but extensive mycorrhizal colonization was recorded in the roots of C. drummondii and C. dactylon. Metal concentrations in plant tissues indicated that I. cylindrica and P. distichum utilized avoidance mechanisms to survive at high metal concentrations. The investigation suggests that remediation and revegetation of heavy metal contaminated sites might be facilitated by selection of tolerant plant species. Isolation of tolerant AM fungi may also be warranted.

  1. Root growth, mycorrhization and physiological effects of plants growing on oil tailing sands

    NASA Astrophysics Data System (ADS)

    Boldt-Burisch, Katja M.; Naeth, Anne M.; Schneider, Bernd Uwe; Hüttl, Reinhard F.

    2015-04-01

    Surface mining creates large, intense disturbances of soils and produces large volumes of by-products and waste materials. After mining processes these materials often provide the basis for land reclamation and ecosystem restoration. In the present study, tailing sands (TS) and processed mature fine tailings (pMFT) from Fort McMurray (Alberta, Canada) were used. They represent challenging material for ecosystem rebuilding because of very low nutrient contents of TS and oil residuals, high density of MFT material. In this context, little is known about the interactions of pure TS, respectively mixtures of TS and MFT and root growth, mycorrhization and plant physiological effects. Four herbaceous plant species (Elymus trachycaulus, Koeleria macrantha, Deschampsia cespitosa, Lotus corniculatus) were chosen to investigate root development, chlorophyll fluorescence and mycorrhization intensity with and without application of Glomus mosseae (arbuscular mycorrhizae) on mainly tailing sands. Surprisingly both, plants growing on pure TS and plants growing on TS with additional AM-application showed mycorrhization of roots. In general, the mycorrhization intensity was lower for plants growing on pure tailings sands, but it is an interesting fact that there is a potential for mycorrhization available in tailing sands. The mycorrhizal intensity strongly increased with application of G. mosseae for K. macrantha and L. corniculatus and even more for E. trachycaulus. For D. cespitosa similar high mycorrhiza infection frequency was found for both variants, with and without AM-application. By the application of G. mosseae, root growth of E. trachycaulus and K. macrantha was significantly positively influenced. Analysis of leaf chlorophyll fluorescence showed no significant differences for E. trachycaulus but significant positive influence of mycorrhizal application on the physiological status of L. corniculatus. However, this effect could not be detected when TS was mixed with MFT

  2. Long-term stability of earthen materials in contact with acidic tailings solutions

    SciTech Connect

    Peterson, S.R.; Erikson, R.L.; Gee, G.W.

    1982-11-01

    The objectives of the studies documented in this report were to use experimental and geochemical computer modeling tools to assess the long-term environmental impact of leachate movement from acidic uranium mill tailings. Liner failure (i.e., an increase in the permeability of the liner material) was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 years. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The high clay materials tested appear suitable for lining tailings impoundment ponds. The decreases in permeability are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. In conclusion the same mineralogical changes and contaminant reactions predicted by geochemical modeling and observed in laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 4 year history of acid attack.

  3. Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings

    SciTech Connect

    Doye, I.; Duchesne, J.

    2005-08-01

    Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

  4. Cytoplasmic tail length influences fatty acid selection for acylation of viral glycoproteins.

    PubMed Central

    Veit, M; Reverey, H; Schmidt, M F

    1996-01-01

    We report remarkable differences in the fatty acid content of thioester-type acylated glycoproteins of enveloped viruses from mammalian cells. The E2 glycoprotein of Semliki Forest virus contains mainly palmitic acid like most other palmitoylated proteins analysed so far. However, the other glycoprotein (E1) of the same virus, as well as the HEF (haemagglutinin esterase fusion) glycoprotein of influenza C virus, are unique in this respect because they are acylated primarily with stearic acid. Comparative radiolabelling of uninfected cells with different fatty acids suggests that stearate may also be the prevailing fatty acid in some cellular acylproteins. To look for further differences between palmitoylated and stearoylated glycoproteins we characterized stearoylation in more detail. We identified the acylation site of HEF as a cysteine residue located at the boundary between the transmembrane region and the cytoplasmic tail. The attachment of stearate to HEF and E1 occurs post-translationally in a pre-Golgi compartment. Thus, stearoylated and palmitoylated proteins cannot be discriminated on the basis of the fatty acid linkage site or the intracellular compartment, where acylation occurs. However, stearoylated acylproteins contain a very short, positively charged cytoplasmic tail, whereas in palmitoylated proteins this molecular region is longer. Replacing the short cytoplasmic tail of stearoylated HEF with the long influenza A virus haemagglutinin (HA) tail in an HEF-HA chimera, and subsequent vaccinia T7 expression in CV-1 cells, yielded proteins with largely palmitic acid bound. The reverse chimera, HA-HEF with a short cytoplasmic tail was not fatty acylated at all during expression, indicating that conformational or topological constraints control fatty acid transfer. PMID:8761467

  5. [Recovery of CO from an ammonia plant tail gas with pressure swing adsorption process].

    PubMed

    Yi, Hong-hong; Ning, Ping; Hao, Ji-ming; Yang, Hao

    2004-09-01

    Ammonia plant tail gas is an important CO source for C1 chemistry if an efficient separation/purification technology is available. Presented is pressure swing adsorption using a home made catalyst PU1 for recovery of CO from ammonia plant tail gas. A performance comparison of PU1 with a commercial zeolite was also presented. The pilot plant experiments were carried out in an intermission one-bed PSA unit with ammonia plant tail gas and a feed flow rate of 0.2-0.8 m3/h. The purity and recovery of CO was studied under various operating conditions. The operating conditions for the process were optimized and an optimum cyclic sequence of operation steps was proposed. A good performance of PU1 in the process was experimentally demonstrated. Product gas with a CO purity over 98% could be produced at a CO recovery of 75% for a feed gas CO concentration of 30% and gas pressure of 0.3 MPa.

  6. Bioaugmentaton in Technosols created in abandoned pyritic tailings can contribute to enhance soil C sequestration and plant colonization.

    PubMed

    Zornoza, Raúl; Gómez-Garrido, Melisa; Martínez-Martínez, Silvia; Gómez-López, María Dolores; Faz, Ángel

    2017-03-24

    Creation of Technosols in combination with phytostabilization may be a sustainable strategy to minimize the environmental and human health hazards derived from mine tailings. Bioaugmentation can facilitate plant establishment and growth for efficient phytostabilization. In order to assess if bioaugmentation can increase soil quality and fertility, decrease metal(loid) mobility and accelerate plant colonization, a one-year field experiment was designed with creation of Technosols in two tailings ponds with different pH (acidic (AT) and neutral (NT)), with addition of marble waste (MaW) and two organic materials (pig manure (PM) and sewage sludge (SS), without or with inoculation of effective microorganisms (EM) at three rates. Results showed that MaW was the main factor responsible for maintaining pH ~7 in AT and ~8 in NT, decreasing salinity, and decreasing the soluble fraction of metals (70-99%). The soluble fraction of As decreased ~45% in AT, related to increases in pH up to neutrality, while increased ~90% in NT with PM due to pH>8 and higher content of organic compounds. The addition of PM and SS significantly increased soil organic C (SOC), nutrient contents and microbial biomass and activity in both tailings, being PM more effective. However, a positive priming effect was observed in NT with SS addition likely due to higher C/N ratio and lack of nutrients. There was a significant effect of EM rate on inorganic C, SOC, N, K and microbial biomass and activity, with higher values as rate increased. Vegetation richness and density directly increased with increasing EM rate. Multivariate analyses showed that the most important properties contributing to increase richness and plant density were microbial biomass and N. Thus, bioaugmentation contributed to soil C sequestration (as organic and inorganic C) and soil fertility, related to high soil microbial biomass and activity, which facilitated an effective colonization of vegetation.

  7. Trichoderma virens PDR-28: a heavy metal-tolerant and plant growth-promoting fungus for remediation and bioenergy crop production on mine tailing soil.

    PubMed

    Babu, A Giridhar; Shim, Jaehong; Bang, Keuk-Soo; Shea, Patrick J; Oh, Byung-Taek

    2014-01-01

    A heavy metal-tolerant fungus, Trichoderma virens PDR-28, was isolated from rhizosphere soil and evaluated for use in remediating mine tailing soil and for plant biomass production. PDR-28 exhibited plant growth-promoting traits, including 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, acid phosphatase and phytase activity, siderophore production, and P solubilization. HMs were more available in mine tailing soil inoculated soil with PDR-28 than in uninoculated soil; the order of HM bioleaching was Cd > As > Zn > Pb > Cu. PDR-28 effectively removed HMs in the order of Pb > Cd > As > Zn > Cu from liquid media containing 100 mg HM L(-1). Inoculating HM-contaminated mine tailing soil with the fungus significantly increased the dry biomass of maize roots (64%) and shoots (56%). Chlorophyll, total soluble sugars (reducible and nonreducible), starch, and protein contents increased by 46%, 28%, 30%, and 29%, respectively, compared to plants grown in uninoculated soil. Inoculation increased heavy metal concentrations in maize roots by 25% (Cu) to 62% (Cd) and in shoots by 35% (Cu) to 64% (Pb) compared to uninoculated plants. Results suggest that PDR-28 would be beneficial for phytostabilization and plant biomass production as a potential source of biofuel in the quest for renewable energy.

  8. Radium-226 contents and Rn emanation coefficients of particle-size fractions of alkaline, acid and mixed U mill tailings.

    PubMed

    Landa, E R

    1987-03-01

    Alkaline circuit and mixed, acid and alkaline circuit U mill tailings sampled at an inactive mill site near Monticello, UT, and tailings from an active, acid-leach U mill were separated into particle-size fractions ranging from +10 mesh to -325 mesh by dry and wet separation techniques. The 226Ra contents and 222Rn emanation coefficients of these fractions were determined. Dry tailings show a high degree of aggregation that tends to mask the relation of properties, such as Ra content and Rn emanating power, to dispersed-particle size. Coarse-tailings fractions (+325 mesh) had emanation coefficients which were from 25 to 45% lower than those of their fine-fraction counterparts. Emanation coefficients measured for tailings derived from a salt roast/carbonate-leach process suggest that such are roasting does not lead to reductions in Rn emanation in the tailings derived therefrom.

  9. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    PubMed

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, p<0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r=0.88, p<0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p<0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent.

  10. Quantitative mineralogical characterization of chrome ore beneficiation plant tailing and its beneficiated products

    NASA Astrophysics Data System (ADS)

    Das, S. K.

    2015-04-01

    Mineralogical characterization and liberation of valuable minerals are primary concerns in mineral processing industries. The present investigation focuses on quantitative mineralogy, elemental deportment, and locking-liberation characteristics of the beneficiation of tailings from a chrome ore beneficiation plant in the Sukinda region, Odisha; methods used for the study of the beneficiated tailings are QEMSCAN®, X-ray diffraction (XRD), and mineral chemistry by a scanning electron microscope equipped with an energy-dispersive spectrometer (SEM-EDS). The tailing sample was fine grained (69.48wt% below 45 μm size), containing 20.25wt% Cr2O3 and 39.19wt% Fe2O3, with a Cr:Fe mass ratio of 0.51. Mineralogical investigations using QEMSCAN studies revealed that chromite, goethite, and gibbsite are the dominant mineral phases with minor amounts of hematite, kaolinite, and quartz. The sample contained 34.22wt% chromite, and chromite liberation is more than 80% for grains smaller than 250 μm in size. Based on these results, it was predicted that liberated chromite and high-grade middling chromite particles could be separated from the gangue by various concentration techniques. The tailing sample was beneficiated by hydrocyclone, tabling, wet high-intensity magnetic separation (WHIMS), and flotation in order to recover the chromite. A chromite concentrate with 45.29wt% Cr2O3 and a Cr:Fe mass ratio of 1.85 can be produced from these low-grade chromite ore beneficiation plant rejects.

  11. [Pb, Zn accumulation and nutrient uptake of 15 plant species grown in abandoned mine tailings].

    PubMed

    Shi, Xiang; Chen, Yi-Tai; Wang, Shu-Feng; Li, Jiang-Chuan

    2012-06-01

    Vegetation restoration field test was carried out in the abandoned lead-zinc tailings for 3 years. The study showed that accumulation of lead (Pb), zinc (Zn) and nutrient uptake differed with plant species and organs, heavy metals, and planting time. Pb was mainly accumulated in tree roots, and its content distribution in tree organs was generally in the order of roots > leaves > stems. But Zn concentrations in leaves of several tree species were higher than those in roots and stems. Within the tested 15 species, Cercis Canadensis had the highest concentrations of Pb and Zn in roots (1 803 and 2120 mg x kg(-1), respectively). Rhus chinensis had the highest Pb concentration in stems and leaves (280 and 546 mg x kg(-1), respectively) and Zn concentration (1 507 mg x kg(-1)) in leaves. Zn concentration in stems and leaves of Salix matsudana (729 and 1 153 mg x kg(-1), respectively) were the highest. Among the tested 15 species, TF values for Pb of Liquidambar formosana, Medicago sativa, and for Zn of Salix matsudana, Rhus chinensis, Medicago sativa were higher than 1. BCF values for Pb were all lower than 0.17, while that for Zn were all lower than 0.44. The N contents in nitrogen-fixing plants, P contents in Rhus typhina and Ailanthus altissima, and K content in Nerium indicum were significantly higher than those in other plants. With the increase of planting time, concentrations of heavy metal in plant body increased significantly; however the inverse trend were observed in nutritional element content. The species have higher metal accumulation capacity, such as Rhus chinensis, Salix matsudana and those nitrogen-fixing plants have higher tolerance to metal contamination and nutrient deficiency, such as Amorpha fruticosa, Medicago sativa, Lespedeza cuneata, and Alnus cremastogyne, they were suitable as the phytostabilizers in abandoned mine tailings.

  12. Quantitative microbial community analysis of three different sulfidic mine tailing dumps generating acid mine drainage.

    PubMed

    Kock, Dagmar; Schippers, Axel

    2008-08-01

    The microbial communities of three different sulfidic and acidic mine waste tailing dumps located in Botswana, Germany, and Sweden were quantitatively analyzed using quantitative real-time PCR (Q-PCR), fluorescence in situ hybridization (FISH), catalyzed reporter deposition-FISH (CARD-FISH), Sybr green II direct counting, and the most probable number (MPN) cultivation technique. Depth profiles of cell numbers showed that the compositions of the microbial communities are greatly different at the three sites and also strongly varied between zones of oxidized and unoxidized tailings. Maximum cell numbers of up to 10(9) cells g(-1) dry weight were determined in the pyrite or pyrrhotite oxidation zones, whereas cell numbers in unoxidized tailings were significantly lower. Bacteria dominated over Archaea and Eukarya at all tailing sites. The acidophilic Fe(II)- and/or sulfur-oxidizing Acidithiobacillus spp. dominated over the acidophilic Fe(II)-oxidizing Leptospirillum spp. among the Bacteria at two sites. The two genera were equally abundant at the third site. The acidophilic Fe(II)- and sulfur-oxidizing Sulfobacillus spp. were generally less abundant. The acidophilic Fe(III)-reducing Acidiphilium spp. could be found at only one site. The neutrophilic Fe(III)-reducing Geobacteraceae as well as the dsrA gene of sulfate reducers were quantifiable at all three sites. FISH analysis provided reliable data only for tailing zones with high microbial activity, whereas CARD-FISH, Q-PCR, Sybr green II staining, and MPN were suitable methods for a quantitative microbial community analysis of tailings in general.

  13. Oil sands thickened froth treatment tailings exhibit acid rock drainage potential during evaporative drying.

    PubMed

    Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

    2015-02-01

    Bitumen extraction from oil sands ores after surface mining produces different tailings waste streams: 'froth treatment tailings' are enriched in pyrite relative to other streams. Tailings treatment can include addition of organic polymers to produce thickened tailings (TT). TT may be further de-watered by deposition into geotechnical cells for evaporative drying to increase shear strength prior to reclamation. To examine the acid rock drainage (ARD) potential of TT, we performed predictive analyses and laboratory experiments on material from field trials of two types of thickened froth treatment tailings (TT1 and TT2). Acid-base accounting (ABA) of initial samples showed that both TT1 and TT2 initially had net acid-producing potential, with ABA values of -141 and -230 t CaCO₃ equiv. 1000 t(-1) of TT, respectively. In long-term kinetic experiments, duplicate ~2-kg samples of TT were incubated in shallow trays and intermittently irrigated under air flow for 459 days to simulate evaporative field drying. Leachates collected from both TT samples initially had pH~6.8 that began decreasing after ~50 days (TT2) or ~250 days (TT1), stabilizing at pH~2. Correspondingly, the redox potential of leachates increased from 100-200 mV to 500-580 mV and electrical conductivity increased from 2-5 dS m(-1) to 26 dS m(-1), indicating dissolution of minerals during ARD. The rapid onset and prolonged ARD observed with TT2 is attributed to its greater pyrite (13.4%) and lower carbonate (1.4%) contents versus the slower onset of ARD in TT1 (initially 6.0% pyrite and 2.5% carbonates). 16S rRNA gene pyrosequencing analysis revealed rapid shift in microbial community when conditions became strongly acidic (pH~2) favoring the enrichment of Acidithiobacillus and Sulfobacillus bacteria in TT. This is the first report showing ARD potential of TT and the results have significant implications for effective management of pyrite-enriched oil sands tailings streams/deposits.

  14. Comparison of the Amino-Acid Content in Pharmacopuncture Extracts Taken from a Scorpion's Body and from Its Tail

    PubMed Central

    Lee, Jin-Ho; Shin, Joon-Shik; Chi, Eun-Hya; Lee, In-Hee

    2013-01-01

    Objective: This study was conducted to investigate the amino-acid compositions of pharmacopuncture extracts taken from the body and from the tail of Buthus martensii Karsch, which are frequently prescribed in Oriental medicine. Methods: Amino acids in hot water and 70% ethanol extracts taken from the scorpion’s whole body and from its tail were screened by using high performance liquid chromatography (HPLC). The experiments were performed with linearity, precision and accuracy. Results: The results of the amino-acid-composition analysis showed that the Buthus martensii Karsch extracts contained various amino acids such as aspartic acid, histidine, alanine, tyrosine, and cystine. The amino-acid analysis showed that the hot water extract was more beneficial than the ethanol extract, except for histidine. The amino acids from the tail and the body of the scorpion were compared, and the concentration of aspartic acid in the extract from the scorpion’s tail was two times that found in the extract from its body. The results of validation experiments were all satisfactory. Conclusion: Studies on the ingredients in extracts from a scorpion other than buthotoxin may demonstrate that the antiepileptic efficacy, anticancer activity, antithrombotic action and analgesic effect are enhanced. Using only the tail of the scorpion when pharmacopuncture is dispensed may be beneficial because the extracts from the tail of the scorpion have higher potency than those from the whole body. PMID:25780666

  15. Enriching acid rock drainage related microbial communities from surface-deposited oil sands tailings.

    PubMed

    Dean, Courtney; Xiao, Yeyuan; Roberts, Deborah J

    2016-10-01

    Little is known about the microbial communities native to surface-deposited pyritic oil sands tailings, an environment where acid rock drainage (ARD) could occur. The goal of this study was to enrich sulfur-oxidizing organisms from these tailings and determine whether different populations exist at pH levels 7, 4.5, and 2.5. Using growth-based methods provides model organisms for use in the future to predict potential activities and limitations of these organisms and to develop possible control methods. Thiosulfate-fed enrichment cultures were monitored for approximately 1 year. The results showed that the enrichments at pH 4.5 and 7 were established quicker than at pH 2.5. Different microbial community structures were found among the 3 pH environments. The sulfur-oxidizing microorganisms identified were most closely related to Halothiobacillus neapolitanus, Achromobacter spp., and Curtobacterium spp. While microorganisms related to Chitinophagaceae and Acidocella spp. were identified as the only possible iron-oxidizing and -reducing microbes. These results contribute to the general knowledge of the relatively understudied microbial communities that exist in pyritic oil sands tailings and indicate these communities may have a potential role in ARD generation, which may have implications for future tailings management.

  16. Investigation of the possibility of copper recovery from the flotation tailings by acid leaching.

    PubMed

    Antonijević, M M; Dimitrijević, M D; Stevanović, Z O; Serbula, S M; Bogdanovic, G D

    2008-10-01

    The flotation tailings pond of the Bor Copper Mine poses a great ecological problem not only for the town of Bor but also for the surrounding soils and watercourses. Since the old flotation tailings contain about 0.2% of copper on the average, we investigated their leaching with sulphuric acid in the absence and presence of an oxidant. The aim was to determine the leaching kinetics of copper and iron as affected by various factors such as: the pH value of the leach solution, stirring speed, pulp density, particle size, concentration of ferric ions, temperature and time for leaching. The average copper and iron recovery obtained was from 60% to 70% and from 2% to 3%, respectively. These results indicate that the old flotation tailings pond represents an important source of secondary raw material for the extraction of copper and that it should be valorized rather than land reclamation. At the end of the paper, a mechanism of dissolution of copper and iron minerals from the tailings was described.

  17. Uptake of Uranium and Other Elements of Concern by Plants Growing on Uranium Mill Tailings Disposal Cells

    NASA Astrophysics Data System (ADS)

    Joseph, C. N.; Waugh, W.; Glenn, E.

    2015-12-01

    The U.S. Department of Energy (DOE) is responsible for long-term stewardship of disposal cells for uranium mill tailings throughout the United States. Rock-armored disposal cell covers create favorable habitat for deep-rooted plants by reducing soil evaporation, increasing soil water storage, and trapping windblown dust, thereby providing water and nutrients for plant germination and establishment. DOE is studying the tradeoffs of potential detrimental and beneficial effects of plants growing on disposal cell covers to develop a rational and consistent vegetation management policy. Plant roots often extend vertically through disposal cell covers into underlying tailings, therefore, uptake of tailings contaminants and dissemination through animals foraging on stems and leaves is a possible exposure pathway. The literature shows that plant uptake of contaminants in uranium mill tailings occurs, but levels can vary widely depending on plant species, tailings and soil chemistry, and cover soil hydrology. Our empirical field study measured concentrations of uranium, radium, thorium, molybdenum, selenium, manganese, lead, and arsenic in above ground tissues harvested from plants growing on disposal cells near Native American communities in western states that represent a range of climates, cover designs, cover soil types, and vegetation types. For risk screening, contaminant levels in above ground tissues harvested from plants on disposal cells were compared to Maximum Tolerance Levels (MTLs) set for livestock by the National Research Council, and to tissue levels in the same plant species growing in reference areas near disposal cells. Although tailings were covered with uncontaminated soils, for 14 of 46 comparisons, levels of uranium and other contaminants were higher in plants growing on disposal cells compared to reference area plants, indicating possible mobilization of these elements from the tailing into plant tissues. However, with one exception, all plant

  18. White-tailed deer alter specialist and generalist insect herbivory through plant traits.

    PubMed

    Lind, Eric M; Myron, Emily P; Giaccai, Jennifer; Parker, John D

    2012-12-01

    Within a plant species, leaf traits can vary across environmental, genetic, spatial, and temporal gradients, even showing drastic differences within individuals. Herbivory can also induce variation in leaf morphology, defensive structure, and chemistry including nutritional content. Indirect effects of prior insect herbivory on later herbivores have been well documented, but the induction of trait changes after vertebrate herbivory has been little explored. Here, we examined how browsing of spicebush (Lindera benzoin L.), a dominant understory shrub in eastern mesic forests, by white-tailed deer (Odocoileus virginianus L.) altered plant quality and subsequent foliar herbivory by insects. Browsing history explained ≈ 10% of overall leaf trait variation; regenerated leaves had greater water content and specific leaf area (P = 0.009), but were lower in nitrogen and greater in carbon (P < 0.001), than leaves on unbrowsed plants. However, browsing did not shift terpene chemistry as revealed by GC-MS. In the lab, caterpillars of the specialist spicebush swallowtail (Papilio troilus L.) preferred (P = 0.02) and grew 20% faster (P = 0.02) on foliage from browsed plants; whereas total herbivory in the field, including generalist insect herbivory, was twice as high on unbrowsed plants (P = 0.016). These results suggest that the ecological impacts of deer in forest understories can have cascading impacts on arthropod communities by changing the suitability of host-plants to insect herbivores.

  19. A membrane process to recover chlorine from chloralkali plant tail gas

    SciTech Connect

    Lokhandwala, K.A.; Segelke, S.; Nguyen, P.; Baker, R.W.; Su, T.T.; Pinnau, I.

    1999-10-01

    Chlorine is manufactured by the electrolysis of brine. The chlorine product is a gas, which is collected, dried, compressed, and cooled to produce a liquid. This paper describes the development and field demonstration of a membrane process to recover chlorine from the liquefaction tail gas of chloralkali plants. The tail gas consists of about 20% chlorine and 50--70% air, with the balance being hydrogen and carbon dioxide. A number of membrane materials can achieve a selectivity of 20 or more for chlorine from nitrogen, but degradation of the membrane materials in the presence of high concentrations of chlorine gas often occurs. However, modified silicone rubber membranes are stable to chlorine gas streams. Silicone rubber composite membranes were prepared and formed into modules of 1--2 m{sup 2} membrane area. The modules were tested in the laboratory and in a field test on a slip stream from a chlorine liquefaction unit. In the laboratory, chlorine/nitrogen membrane selectivities of more than 40 were obtained, but selectivities of 6--10 were measured in the field test. This decrease in selectivity was caused by low gas flow rates through the modules, which resulted in concentration polarization effects. However, the membrane maintained essentially constant fluxes and selectivities in field tests lasting more than 1 month. Calculated plant designs based on a selectivity of 8 are able to recover more than 95% of the chlorine in the tail gas. Typical project payback times based on the value of the recovered chlorine and avoided caustic scrubber chemical use are expected to be 1--2 years.

  20. Plant community and white-tailed deer nutritional carrying capacity response to intercropping switchgrass in loblolly pine plantations

    NASA Astrophysics Data System (ADS)

    Greene, Ethan Jacob

    Switchgrass (Panicum virgatum L.) is a cellulosic feedstock for alternative energy production that could grow well between planted pines (Pinus spp.). Southeastern planted pine occupies 15.8 million hectares and thus, switchgrass intercropping could affect biodiversity if broadly implemented. Therefore, I evaluated effects of intercropping switchgrass in loblolly pine (P. taeda L.) plantations on plant community diversity, plant biomass production, and white-tailed deer (Odocoileus virginianus Zimmerman) nutritional carrying capacity. In a randomized complete block design, I assigned three treatments (switchgrass intercropped, switchgrass monoculture, and a "control" of traditional pine management) to 4 replicates of 10-ha experimental units in Kemper County, Mississippi during 2014-2015. I detected 246 different plant species. Switchgrass intercropping reduced plant species richness and diversity but maintained evenness. I observed reduced forb and high-use deer forage biomass but only in intercropped alleys (interbeds). Soil micronutrient interactions affected forage protein of deer plants. White-tailed deer nutritional carrying capacity remained unaffected.

  1. Laboratory evaluation of limestone and lime neutralization of acidic uranium mill tailings solution. Progress report

    SciTech Connect

    Opitz, B.E.; Dodson, M.E.; Serne, R.J.

    1984-02-01

    Experiments were conducted to evaluate a two-step neutralization scheme for treatment of acidic uranium mill tailings solutions. Tailings solutions from the Lucky Mc Mill and Exxon Highland Mill, both in Wyoming, were neutralized with limestone, CaCO/sub 3/, to an intermediate pH of 4.0 or 5.0, followed by lime, Ca(OH)/sub 2/, neutralization to pH 7.3. The combination limestone/lime treatment methods, CaCO/sub 3/ neutralization to pH 4 followed by neutralization with Ca(OH)/sub 2/ to pH 7.3 resulted in the highest quality effluent solution with respect to EPA's water quality guidelines. The combination method is the most cost-effective treatment procedure tested in our studies. Neutralization experiments to evaluate the optimum solution pH for contaminant removal were performed on the same two tailings solutions using only lime Ca(OH)/sub 2/ as the neutralizing agent. The data indicate solution neutralization above pH 7.3 does not significantly increase removal of pH dependent contaminants from solution. Column leaching experiments were performed on the neutralized sludge material (the precipitated solid material which forms as the acidic tailings solutions are neutralized to pH 4 or above). The sludges were contacted with laboratory prepared synthetic ground water until several effluent pore volumes were collected. Effluent solutions were analyzed for macro ions, trace metals and radionuclides in an effort to evaluate the long term effectiveness of attenuating contaminants in sludges formed during solution neutralization. Neutralized sludge leaching experiments indicate that Ca, Na, Mg, Se, Cl, and SO/sub 4/ are the only constituents which show solution concentrations significantly higher than the synthetic ground water in the early pore volumes of long-term leaching studies.

  2. Amino acid residues 201-205 in C-terminal acidic tail region plays a crucial role in antibacterial activity of HMGB1

    PubMed Central

    2009-01-01

    Background Antibacterial activity is a novel function of high-mobility group box 1 (HMGB1). However, the functional site for this new effect is presently unknown. Methods and Results In this study, recombinant human HMGB1 A box and B box (rHMGB1 A box, rHMGB1 B box), recombinant human HMGB1 (rHMGB1) and the truncated C-terminal acidic tail mutant (tHMGB1) were prepared by the prokaryotic expression system. The C-terminal acidic tail (C peptide) was synthesized, which was composed of 30 amino acid residues. Antibacterial assays showed that both the full length rHMGB1 and the synthetic C peptide alone could efficiently inhibit bacteria proliferation, but rHMGB1 A box and B box, and tHMGB1 lacking the C-terminal acidic tail had no antibacterial function. These results suggest that C-terminal acidic tail is the key region for the antibacterial activity of HMGB1. Furthermore, we prepared eleven different deleted mutants lacking several amino acid residues in C-terminal acidic tail of HMGB1. Antibacterial assays of these mutants demonstrate that the amino acid residues 201-205 in C-terminal acidic tail region is the core functional site for the antibacterial activity of the molecule. Conclusion In sum, these results define the key region and the crucial site in HMGB1 for its antibacterial function, which is helpful to illustrating the antibacterial mechanisms of HMGB1. PMID:19751520

  3. Phenol biosynthesis in higher plants. Gallic acid

    PubMed Central

    Dewick, P. M.; Haslam, E.

    1969-01-01

    The biosynthesis of gallic acid in a number of higher plants was investigated by using l-[U-14C]phenylalanine, (−)-[G-14C]shikimic acid, d-[1-14C]glucose and d-[6-14C]glucose as tracers. The results are compared with those obtained similarly for caffeic acid and are interpreted in terms of the dehydrogenation of 5-dehydroshikimic acid as a normal route of metabolism for gallic acid. PMID:5807212

  4. Growth of Quailbush in Acidic, Metalliferous Desert Mine Tailings: Effect of Azospirillum brasilense Sp6 on Biomass Production and Rhizosphere Community Structure

    PubMed Central

    de-Bashan, Luz E.; Hernandez, Juan-Pablo; Nelson, Karis N.; Bashan, Yoav

    2010-01-01

    Mine tailing deposits in semiarid and arid environments frequently remain devoid of vegetation due to the toxicity of the substrate and the absence of a diverse soil microbial community capable of supporting seed germination and plant growth. The contribution of the plant growth promoting bacterium (PGPB) Azospirillum brasilense Sp6 to the growth of quailbush in compost-amended, moderately acidic, high-metal content mine tailings using an irrigation-based reclamation strategy was examined along with its influence on the rhizosphere bacterial community. Sp6 inoculation resulted in a significant (2.2-fold) increase in plant biomass production. The data suggest that the inoculum successfully colonized the root surface and persisted throughout the 60-day experiment in both the rhizosphere, as demonstrated by excision and sequencing of the appropriate denaturing gradient gel electrophoresis (DGGE) band, and the rhizoplane, as indicated by fluorescent in situ hybridization of root surfaces. Changes in rhizosphere community structure in response to Sp6 inoculation were evaluated after 15, 30, and 60 days using DGGE analysis of 16S rRNA polymerase chain reaction amplicons. A comparison of DGGE profiles using canonical correspondence analysis revealed a significant treatment effect (Sp6-inoculated vs. uninoculated plants vs. unplanted) on bacterial community structure at 15, 30, and 60 days (p<0.05). These data indicate that in an extremely stressed environment such as acid mine tailings, an inoculated plant growth promoting bacterium not only can persist and stimulate plant growth but also can directly or indirectly influence rhizobacterial community development. PMID:20632001

  5. Efficient degradation of Acid Orange 7 in aqueous solution by iron ore tailing Fenton-like process.

    PubMed

    Zheng, Jianming; Gao, Zhanqi; He, Huan; Yang, Shaogui; Sun, Cheng

    2016-05-01

    An effective method based on iron ore tailing Fenton-like process was studied for removing an azo dye, Acid Orange 7 (AO7) in aqueous solution. Five tailings were characterized by X-ray fluorescence spectroscope (XFS), Brunner-Emmet-Teller (BET) measurement, and Scanning Electron Microscope (SEM). The result of XFS showed that Fe, Si and Ca were the most abundant elements and some toxic heavy metals were also present in the studied tailings. The result of BET analysis indicated that the studied tailings had very low surface areas (0.64-5.68 m(2) g(-1)). The degradation efficiencies of AO7 were positively correlated with the content of iron oxide and cupric oxide, and not related with the BET surface area of the tailings. The co-existing metal elements, particularly Cu, might accelerate the heterogeneous Fenton-like reaction. The effects of other parameters on heterogeneous Fenton-like degradation of AO7 by a converter slag iron tailing (tailing E) which contains highest iron oxide were also investigated. The tailing could be reused 10 times without significant decrease of the catalytic capacity. Very low amount of iron species and almost undetectable toxic elements were leached in the catalytic degradation of AO7 by the tailing E. The reaction products were identified by gas chromatography-mass spectrometry and a possible pathway of AO7 degradation was proposed. This study not only provides an effective method for removing azo dyes in polluted water by employing waste tailings as Fenton-like catalysts, but also uses waste tailings as the secondary resource.

  6. Effects of sewage sludge on pH and plant availability of metals in oxidising sulphide mine tailings.

    PubMed

    Forsberg, Lovisa Stjernman; Ledin, Stig

    2006-04-01

    A field study was conducted adjacent to the tailings deposit of the Aitik copper mine in the north of Sweden to investigate the effects of sewage sludge on pH and plant availability of Al, Mn, Cu, Zn, Ni, Pb, As, Cr and Cd in the oxidising sulphide tailings. One treatment was supplied with sewage sludge, while the control received NPK-fertiliser. The tailings samples were collected at the beginning and the end of the growing season and extracted by NH(4)NO(3), NH(4)Ac-EDTA and HNO(3). Plant tissue concentrations of the elements were determined in the above-ground parts of barley (Hordeum vulgare) and red fescue (Festuca rubra). The application of sewage sludge resulted in higher crop yields compared to the control, although the buffering capacity and the metal immobilising effect of the sludge were limited. The pH decreased from 6.6 to 4.3 in the control and from 6.4 to 4.8 in the sludge-treated tailings during the growing season, probably due to sulphide oxidation in the tailings. This resulted in increased levels of soluble elements in all treatments studied. Application of sewage sludge resulted in elevated levels of soluble Zn and lower values of soluble As and Cd in the unaltered tailings but increased levels of specifically adsorbed Cu, Ni and As in the oxidised tailings. This was partly reflected in the plants, as the application of sewage sludge resulted in 67 mg Zn kg(-1) in barley grains and 60 mg Zn kg(-1) in red fescue shoots, both values twice as high as the corresponding values in the control, but lower As contents in both straw (0.3 mg kg(-1)) and grain (0.06 mg kg(-1)) of barley compared to the control (0.6 and 0.2 mg kg(-1), respectively). In addition, red fescue grown in sludge-treated plots contained significantly higher levels of Al, Cu, Pb, As and Cr compared to the control. The levels of several metals in barley and red fescue grown in both treatments exceeded background values found in the literature. The Cu content in barley straw exceeded

  7. Heavy metals concentration in plants growing on mine tailings in Central Mexico.

    PubMed

    Franco-Hernández, M O; Vásquez-Murrieta, M S; Patiño-Siciliano, A; Dendooven, L

    2010-06-01

    Metal concentrations were measured in plants growing on heavily contaminated tailings from a mine active since about 1800 in San Luis Potosí (Mexico). Viguiera dentata (Cav.) Spreng., Parthenium bipinnatifidum (Ort.) Rollins, Flaveria angustifolia (Cav.) Pers., F. trinervia (Spreng.) C. Mohr. and Sporobolusindicus (L.) R. Br. were tolerant to high As, Cu, Pb and Zn concentrations. Of those, S.indicus excluded heavy metals from its shoots, while P. bipinnatifidum and F. angustifolia accumulated them. V. dentata and P. bipinnatifidum were accumulators of As, but not hyperaccumulators. It was found that V. dentata,P. bipinnatifidum, F. angustifolia, F. trinervia and S.indicus, could be used to vegetate soils contaminated with As, Cu, Pb and Zn. Ambrosiaartemisifolia could be used to remediate soils contaminated with Zn, S. amplexicaulis those with Cu and F. angustifolia and F. trinervia those with As, as they have a strong capacity to accumulate those metals.

  8. [Distribution characteristics of soil nematodes in reclaimed land of copper-mine-tailings in different plant associations].

    PubMed

    Zhu, Yong-heng; Li, Ke-zhong; Zhang, Heng; Han, Fei; Zhou, Ju-hua; Gao, Ting-ting

    2015-02-01

    A survey was carried out to investigate soil nematode communities in the plant associations of gramineae (Arthraxon lanceolatus, AL; Imperata cylindrica, IC) and leguminosae (Glycine soja, GS) in reclaimed land of copper-mine-tailings and in the plant associations of gramineae (Digitaria chrysoblephara, DC-CK) of peripheral control in Fenghuang Mountain, Tongling City. A total of 1277 nematodes were extracted and sorted into 51 genera. The average individual density of the nematodes was 590 individuals · 100 g(-1) dry soil. In order to analyze the distribution character- istics of soil nematode communities in reclaimed land of copper-mine-tailings, Shannon community diversity index and soil food web structure indices were applied in the research. The results showed that the total number of nematode genus and the Shannon community diversity index of soil nematode in the three plant associations of AL, IC and GS were less than that in the plant associations of DC-CK. Compared with the ecological indices of soil nematode communities among the different plant associations in reclaimed land of copper-mine-tailings and peripheral natural habitat, we found that the structure of soil food web in the plant associations of GS was more mature, with bacterial decomposition being dominant in the soil organic matter decomposition, and that the soil ecosystem in the plant associations of GS was not stable with low interference. This indicated that the soil food web in the plant associations of leguminosae had a greater development potential to improve the ecological stability of the reclaimed land of copper-mine-tailings. On the other hand, the structure of soil food web in the plant associations of AL and IC were relatively stable in a structured state with fungal decomposition being dominant in the decomposition of soil organic matter. This indicated that the soil food web in the plant associations of gramineae was at a poor development level.

  9. Metabolism of branched-chain amino acids in leg muscles from tail-cast suspended intact and adrenalectomized rats

    NASA Technical Reports Server (NTRS)

    Jaspers, Stephen R.; Henriksen, Erik; Jacob, Stephan; Tischler, Marc E.

    1989-01-01

    The effects of muscle unloading, adrenalectomy, and cortisol treatment on the metabolism of branched-chain amino acids in the soleus and extensor digitorum longus of tail-cast suspended rats were investigated using C-14-labeled lucine, isoleucine, and valine in incubation studies. It was found that, compared to not suspended controls, the degradation of branched-chain amino acids in hind limb muscles was accelerated in tail-cast suspended rats. Adrenalectomy was found to abolish the aminotransferase flux and to diminish the dehydrogenase flux in the soleus. The data also suggest that cortisol treatment increases the rate of metabolism of branched-chain amino acids at the dehydrogenase step.

  10. Nutritional restriction and acid-base balance in white-tailed deer

    USGS Publications Warehouse

    DelGiudice, G.D.; Mech, L.D.; Seal, U.S.

    1994-01-01

    We examined the effect of progressive nutritional restriction on acid-base balance in seven captive, adult white-tailed deer (Odocoileus virginianus) from 4 February to 5 May 1988 in north central Minnesota (USA). Metabolic acidosis was indicated by low mean blood pH (7.25 to 7.33) in deer throughout the study. Mean urinary pH values declined (P = 0.020) from a mean (+SE) baseline of 8.3 +0.1 to 6.7 + 0.3 as restriction progressed. Acidemia and aciduria were associated with significant variations in mean blood CO2 (P = 0.006) and pO2 (P = 0.032), serum potassium (P = 0.004) concentrations, and with a significant (P = 0.104) handling date times group interaction in urinary potassium:creatinine values. Mean bicarbonate:carbonic acid ratios were consistently below 20:1 during nutritional restriction. Mean packed cell volume increased (P = 0.019) and serum total protein decreased (P = 0.001); thus there was evidence for progressive dehydration and net protein catabolism, respectively. Blood pCO2, serum sodium, and urinary sodium:creatinine were stable throughout the study. We propose that acidosis and aciduria are metabolic complications associated with nutritional restriction of white-tailed deer.

  11. Amino Acid Uptake in Arbuscular Mycorrhizal Plants

    PubMed Central

    Whiteside, Matthew D.; Garcia, Maria O.; Treseder, Kathleen K.

    2012-01-01

    We examined the extent to which arbuscular mycorrhizal (AM) fungi root improved the acquisition of simple organic nitrogen (ON) compounds by their host plants. In a greenhouse-based study, we used quantum dots (fluorescent nanoparticles) to assess uptake of each of the 20 proteinaceous amino acids by AM-colonized versus uncolonized plants. We found that AM colonization increased uptake of phenylalanine, lysine, asparagine, arginine, histidine, methionine, tryptophan, and cysteine; and reduced uptake of aspartic acid. Arbuscular mycorrhizal colonization had the greatest effect on uptake of amino acids that are relatively rare in proteins. In addition, AM fungi facilitated uptake of neutral and positively-charged amino acids more than negatively-charged amino acids. Overall, the AM fungi used in this study appeared to improve access by plants to a number of amino acids, but not necessarily those that are common or negatively-charged. PMID:23094070

  12. Plant microRNAs display differential 3' truncation and tailing modifications that are ARGONAUTE1 dependent and conserved across species.

    PubMed

    Zhai, Jixian; Zhao, Yuanyuan; Simon, Stacey A; Huang, Sheng; Petsch, Katherine; Arikit, Siwaret; Pillay, Manoj; Ji, Lijuan; Xie, Meng; Cao, Xiaofeng; Yu, Bin; Timmermans, Marja; Yang, Bing; Chen, Xuemei; Meyers, Blake C

    2013-07-01

    Plant small RNAs are 3' methylated by the methyltransferase HUA1 ENHANCER1 (HEN1). In plant hen1 mutants, 3' modifications of small RNAs, including oligo-uridylation (tailing), are associated with accelerated degradation of microRNAs (miRNAs). By sequencing small RNAs of the wild type and hen1 mutants from Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays), we found 3' truncation prior to tailing is widespread in these mutants. Moreover, the patterns of miRNA truncation and tailing differ substantially among miRNA families but are conserved across species. The same patterns are also observable in wild-type libraries from a broad range of species, only at lower abundances. ARGONAUTE (AGO1), even with defective slicer activity, can bind these truncated and tailed variants of miRNAs. An ago1 mutation in hen1 suppressed such 3' modifications, indicating that they occur while miRNAs are in association with AGO1, either during or after RNA-induced silencing complex assembly. Our results showed AGO1-bound miRNAs are actively 3' truncated and tailed, possibly reflecting the activity of cofactors acting in conserved patterns in miRNA degradation.

  13. Differential distribution of amino acids in plants.

    PubMed

    Kumar, Vinod; Sharma, Anket; Kaur, Ravdeep; Thukral, Ashwani Kumar; Bhardwaj, Renu; Ahmad, Parvaiz

    2017-05-01

    Plants are a rich source of amino acids and their individual abundance in plants is of great significance especially in terms of food. Therefore, it is of utmost necessity to create a database of the relative amino acid contents in plants as reported in literature. Since in most of the cases complete analysis of profiles of amino acids in plants was not reported, the units used and the methods applied and the plant parts used were different, amino acid contents were converted into relative units with respect to lysine for statistical analysis. The most abundant amino acids in plants are glutamic acid and aspartic acid. Pearson's correlation analysis among different amino acids showed that there were no negative correlations between the amino acids. Cluster analysis (CA) applied to relative amino acid contents of different families. Alismataceae, Cyperaceae, Capparaceae and Cactaceae families had close proximity with each other on the basis of their relative amino acid contents. First three components of principal component analysis (PCA) explained 79.5% of the total variance. Factor analysis (FA) explained four main underlying factors for amino acid analysis. Factor-1 accounted for 29.4% of the total variance and had maximum loadings on glycine, isoleucine, leucine, threonine and valine. Factor-2 explained 25.8% of the total variance and had maximum loadings on alanine, aspartic acid, serine and tyrosine. 14.2% of the total variance was explained by factor-3 and had maximum loadings on arginine and histidine. Factor-4 accounted 8.3% of the total variance and had maximum loading on the proline amino acid. The relative content of different amino acids presented in this paper is alanine (1.4), arginine (1.8), asparagine (0.7), aspartic acid (2.4), cysteine (0.5), glutamic acid (2.8), glutamine (0.6), glycine (1.0), histidine (0.5), isoleucine (0.9), leucine (1.7), lysine (1.0), methionine (0.4), phenylalanine (0.9), proline (1.1), serine (1.0), threonine (1

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Tailings usually provide an unfavourable substrate for plant growth because of their extreme pH, low organic matter and nutrients, high concentrations of trace elements and physical disturbance, such as bad soil structure, and low water availability. Heavy metal contamination has also been one serious problem in the vicinity of mine sites due to the discharge and dispersion of mine-waste materials into the ecosystem. Moreover, Pb is considered a target metal when undertaking soil remediation, because it is usually quite immobile and not readily accumulated in upper plant parts. The presence of vegetation reduces water and wind erosion, which may decrease the downward migration of contaminants into the groundwater and improve aesthetical aspects. Plants growing on naturally metal-enriched soils are of particular interest in this perspective, since they are genetically tolerant to high metal concentrations, have an excellent adaptation to this multi-stress environment. Efficient phytoextraction requires plant species combining both high metal tolerance and elevated capacity for metal uptake and metal translocation to easily harvestable plant organs (e.g. shoots). Soil and plant samples were taken in Peru, at a polymetallic mine (mainly Ag, Pb and Cu) in Cajamarca Province, Hualgayoc district. Top soils (0-20 cm) were analysed for physical and chemical properties by standard methods. Total Pb concentrations in top soils were determined by ICP-OES. Pb content in plants were analysed separately (aerial and root system) by ICP-MS. Ti content was used as an indicator for contamination of plant samples with soil particles. Translocation Factor (TF) and Shoot Accumulation Factor (SAF) were determined to assess the tolerance strategies developed by these species and to evaluate their potential for phytoremediation purposes. The non-polluted soils had near neutral pH (6.8±0.1), a great content of organic carbon (42 ± 4.0 g•kg-1) and a silt loamy texture. Soil and plant

  15. Culturable and molecular phylogenetic diversity of microorganisms in an open-dumped, extremely acidic Pb/Zn mine tailings.

    PubMed

    Tan, Gui-Liang; Shu, Wen-Sheng; Hallberg, Kevin B; Li, Fang; Lan, Chong-Yu; Zhou, Wen-Hua; Huang, Li-Nan

    2008-09-01

    A combination of cultivation-based and molecular-based approaches was used to reveal the culturable and molecular diversity of the microbes inhabiting an open-dumped Pb/Zn mine tailings that was undergoing intensive acid generation (pH 1.9). Culturable bacteria found in the extremely acidic mine tailings were Acidithiobacillus ferrooxidans, Leptospirillum ferriphilum, Sulfobacillus thermotolerans and Acidiphilium cryptum, where the number of acidophilic heterotrophs was ten times higher than that of the iron- and sulfur-oxidizing bacteria. Cloning and phylogenetic analysis revealed that, in contrast to the adjacent AMD, the mine tailings possessed a low microbial diversity with archaeal sequence types dominating the 16S rRNA gene library. Of the 141 clones examined, 132 were represented by two sequence types phylogenetically affiliated with the iron-oxidizing archaea Ferroplasma acidiphilum and three belonged to two tentative groups within the Thermoplasma lineage so far represented by only a few environmental sequences. Six clones in the library were represented by the only bacterial sequence type and were closely related to the well-described iron-oxidizer L. ferriphilum. The significant differences in the prokaryotic community structures of the extremely acidic mine tailings and the AMD associated with it highlights the importance of studying the microbial communities that are more directly involved in the iron and sulfur cycles of mine tailings.

  16. Trace metal mobilization from oil sands froth treatment thickened tailings exhibiting acid rock drainage.

    PubMed

    Kuznetsova, Alsu; Kuznetsov, Petr; Foght, Julia M; Siddique, Tariq

    2016-11-15

    Froth treatment thickened tailings (TT) are a waste product of bitumen extraction from surface-mined oil sands ores. When incubated in a laboratory under simulated moist oxic environmental conditions for ~450d, two different types of TT (TT1 and TT2) exhibited the potential to generate acid rock drainage (ARD) by producing acid leachate after 250 and 50d, respectively. We report here the release of toxic metals from TT via ARD, which could pose an environmental threat if oil sands TT deposits are not properly managed. Trace metal concentrations in leachate samples collected periodically revealed that Mn and Sr were released immediately even before the onset of ARD. Spikes in Co and Ni concentrations were observed both pre-ARD and during active ARD, particularly in TT1. For most elements measured (Fe, Cr, V, As, Cu, Pb, Zn, Cd, and Se), leaching was associated with ARD production. Though equivalent acidification (pH2) was achieved in leachate from both TT types, greater metal release was observed from TT2 where concentrations reached 10,000ppb for Ni, 5000ppb for Co, 3000ppb for As, 2000ppb for V, and 1000ppb for Cr. Generally, metal concentrations decreased in leachate with time during ARD and became negligible by the end of incubation (~450d) despite appreciable metals remaining in the leached TT. These results suggest that using TT for land reclamation purposes or surface deposition for volume reduction may unfavorably impact the environment, and warrants application of appropriate strategies for management of pyrite-enriched oil sands tailings streams.

  17. Pyroligneous acid-the smoky acidic liquid from plant biomass.

    PubMed

    Mathew, Sindhu; Zakaria, Zainul Akmar

    2015-01-01

    Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food.

  18. Efficient inhibition of heavy metal release from mine tailings against acid rain exposure by triethylenetetramine intercalated montmorillonite (TETA-Mt).

    PubMed

    Gong, Beini; Wu, Pingxiao; Huang, Zhujian; Li, Yuanyuan; Yang, Shanshan; Dang, Zhi; Ruan, Bo; Kang, Chunxi

    2016-11-15

    The potential application of triethylenetetramine intercalated montmorillonite (TETA-Mt) in mine tailings treatment and AMD (acid mine drainage) remediation was investigated with batch experiments. The structural and morphological characteristics of TETA-Mt were analyzed with XRD, FTIR, DTG-TG and SEM. The inhibition efficiencies of TETA-Mt against heavy metal release from mine tailings when exposed to acid rain leaching was examined and compared with that of triethylenetetramine (TETA) and Mt. Results showed that the overall inhibition by TETA-Mt surpassed that by TETA or Mt for various heavy metal ions over an acid rain pH range of 3-5.6 and a temperature range of 25-40°C. When mine tailings were exposed to acid rain of pH 4.8 (the average rain pH of the mining site where the mine tailings were from), TETA-Mt achieved an inhibition efficiency of over 90% for Cu(2+), Zn(2+), Cd(2+) and Mn(2+) release, and 70% for Pb(2+) at 25°C. It was shown that TETA-Mt has a strong buffering capacity. Moreover, TETA-Mt was able to adsorb heavy metal ions and the adsorption process was fast, suggesting that coordination was mainly responsible. These results showed the potential of TETA-Mt in AMD mitigation, especially in acid rain affected mining area.

  19. Manganese ore tailing: optimization of acid leaching conditions and recovery of soluble manganese.

    PubMed

    Santos, Olívia de Souza Heleno; Carvalho, Cornélio de Freitas; Silva, Gilmare Antônia da; Santos, Cláudio Gouvêa Dos

    2015-01-01

    Manganese recovery from industrial ore processing waste by means of leaching with sulfuric acid was the objective of this study. Experimental conditions were optimized by multivariate experimental design approaches. In order to study the factors affecting leaching, a screening step was used involving a full factorial design with central point for three variables in two levels (2(3)). The three variables studied were leaching time, concentration of sulfuric acid and sample amount. The three factors screened were shown to be relevant and therefore a Doehlert design was applied to determine the best working conditions for leaching and to build the response surface. By applying the best leaching conditions, the concentrations of 12.80 and 13.64 %w/w of manganese for the global sample and for the fraction -44 + 37 μm, respectively, were found. Microbeads of chitosan were tested for removal of leachate acidity and recovering of soluble manganese. Manganese recovery from the leachate was 95.4%. Upon drying the leachate, a solid containing mostly manganese sulfate was obtained, showing that the proposed optimized method is efficient for manganese recovery from ore tailings.

  20. Spatial and Temporal Analysis of the Microbial Community in the Tailings of a Pb-Zn Mine Generating Acidic Drainage ▿ †

    PubMed Central

    Huang, Li-Nan; Zhou, Wen-Hua; Hallberg, Kevin B.; Wan, Cai-Yun; Li, Jie; Shu, Wen-Sheng

    2011-01-01

    Analysis of spatial and temporal variations in the microbial community in the abandoned tailings impoundment of a Pb-Zn mine revealed distinct microbial populations associated with the different oxidation stages of the tailings. Although Acidithiobacillus ferrooxidans and Leptospirillum spp. were consistently present in the acidic tailings, acidophilic archaea, mostly Ferroplasma acidiphilum, were predominant in the oxidized zones and the oxidation front, indicating their importance to generation of acid mine drainage. PMID:21705549

  1. In search of tail-anchored protein machinery in plants: reevaluating the role of arsenite transporters

    PubMed Central

    Maestre-Reyna, Manuel; Wu, Shu-Mei; Chang, Yu-Ching; Chen, Chi-Chih; Maestre-Reyna, Alvaro; Wang, Andrew H.-J.; Chang, Hsin-Yang

    2017-01-01

    Although the mechanisms underlying selective targeting of tail-anchored (TA) membrane proteins are well established in mammalian and yeast cells, little is known about their role in mediating intracellular membrane trafficking in plant cells. However, a recent study suggested that, in green algae, arsenite transporters located in the cytosol (ArsA1 and ArsA2) control the insertion of TA proteins into the membrane-bound organelles. In the present work, we overproduced and purified these hydrophilic proteins to near homogeneity. The analysis of their catalytic properties clearly demonstrates that C. reinhardtii ArsA proteins exhibit oxyanion-independent ATPase activity, as neither arsenite nor antimonite showed strong effects. Co-expression of ArsA proteins with TA-transmembrane regions showed not only that the former interact with the latter, but that ArsA1 does not share the same ligand specificity as ArsA2. Together with a structural model and molecular dynamics simulations, we propose that C. reinhadtii ArsA proteins are not arsenite transporters, but a TA-protein targeting factor. Further, we propose that ArsA targeting specificity is achieved at the ligand level, with ArsA1 mainly carrying TA-proteins to the chloroplast, while ArsA2 to the endoplasmic reticulum. PMID:28382961

  2. Comparison of the meat quality and fatty acid composition of traditional fat-tailed (Chall) and tailed (Zel) Iranian sheep breeds.

    PubMed

    Yousefi, Ali Reza; Kohram, Hamid; Zare Shahneh, Ahmad; Nik-khah, Ali; Campbell, Anna W

    2012-12-01

    The aim of this study was to compare the meat quality of a traditional fat-tailed breed, Chall, to a tailed Iranian sheep breed, Zel. Lambs were grazed on pasture until weaning, and then were finished until slaughter at 10-12 months. Meat quality traits were measured on the longissimus dorsi (LD) muscle. Zel lambs accumulated more intramuscular fat (IMF) (p<0.01) and had lower shear force and drip loss than Chall lambs (p<0.05). The meat color of Zel lambs was higher for both a* (p<0.001) and b* (p<0.01) compared to Chall lambs. Meat from Zel lambs was more tender (p<0.01) and more juicy (p<0.05) than Chall lambs. The PUFA:SFA fatty acid ratio (P:S) was higher (p<0.05) and the n-6:n-3 PUFA ratio was lower in Chall compared to Zel lambs (p<0.05). Overall, these results show that the eating quality of Zel lambs was better, but that this was at the cost of less favorable fatty acid profiles and poorer meat color.

  3. Extensive analysis of milk fatty acids in two fat-tailed sheep breeds during lactation.

    PubMed

    Payandeh, S; Kafilzadeh, F; Juárez, M; de la Fuente, M A; Ghadimi, D; Marín, A L Martínez

    2016-12-01

    The profile of fatty acids (FA) in the milk fat of two Iranian fat-tailed sheep breeds, Sanjabi and Mehraban, was compared during lactation. Eight ewes of each breed, balanced in parity and carrying one foetus, were selected before parturition. Ewes were kept separated in individual pens during the experimental period, under the same management practices and fed the same diet, in order to eliminate any confounding effects on milk FA profile. Milk was sampled at biweekly intervals up to 10 weeks of lactation, starting 2 weeks after parturition. More than 100 FA were determined in milk fat by means of gas chromatography. The milk fat of Sanjabi ewes contained more cis-9 18:1, that of Mehraban ewes was richer in 10:0, 12:0 and 14:0, and no differences were found for 16:0 and 18:0. No breed differences were found for most branched-chain FA. Mehraban ewes showed a higher presence of vaccenic and rumenic acids in their milk fat. The milk fat of Sanjabi ewes had a lower atherogenicity index and n-6/n-3 FA ratio. The contents of several FA showed time-dependent changes, so breed differences were more apparent or disappeared as lactation progressed. The milk fat of Sanjabi ewes showed a better FA profile from the human health point of view.

  4. [Study on the acid hydrolysis, fiber remodeling and bionics mineralization of rat tail tendon collagen type Ⅰ].

    PubMed

    Zhang, Zhan; Zhang, Chun; Guo, Qiaofeng

    2016-05-25

    Objective: To produce bionic bone material that is consistent with human bone in chemical composition and molecular structure using rat tail tendon collagen type Ⅰ. Methods: The type Ⅰcollagen derived from rat tail was extracted by acetic acid to form collagen fibers. The reconstructed collagen fibers were placed in the mineralized solution to mimic bone mineralization for 2-6 days. Bone mineralization was observed by transmission electron microscopy and electron diffraction.Results: Collagen fibers with characteristic D-Band structure were reconstructed by using rat tail tendon collagen type Ⅰ extracted with acid hydrolysis method. Transmission electron microscopy and electron diffraction showed that calcium hydroxyapatite precursor infiltrated into the collagen fibers, and the collagen fibers were partially mineralized after 2 days of mineralization; the collagen fibers were completely mineralized and bionic bone material of typeⅠ collagen/calcium hydroxyapatite was formed after 6 days of mineralization.Conclusion: The collagen type Ⅰ can be extracted from rat tail tendon by acid hydrolysis method, and can be reformed and mineralized to form the bionic bone material which mimics human bone in chemical composition and the molecular structure.

  5. Culturable Heavy Metal-Resistant and Plant Growth Promoting Bacteria in V-Ti Magnetite Mine Tailing Soil from Panzhihua, China

    PubMed Central

    Zhang, Chu; Liu, Huiying; Liu, Jin; Zheng, Wenwen; Kang, Xia; Leng, Xuejun; Zhao, Ke; Gu, Yunfu; Zhang, Xiaoping; Xiang, Quanju; Chen, Qiang

    2014-01-01

    To provide a basis for using indigenous bacteria for bioremediation of heavy metal contaminated soil, the heavy metal resistance and plant growth-promoting activity of 136 isolates from V-Ti magnetite mine tailing soil were systematically analyzed. Among the 13 identified bacterial genera, the most abundant genus was Bacillus (79 isolates) out of which 32 represented B. subtilis and 14 B. pumilus, followed by Rhizobium sp. (29 isolates) and Ochrobactrum intermedium (13 isolates). Altogether 93 isolates tolerated the highest concentration (1000 mg kg−1) of at least one of the six tested heavy metals. Five strains were tolerant against all the tested heavy metals, 71 strains tolerated 1,000 mg kg−1 cadmium whereas only one strain tolerated 1,000 mg kg−1 cobalt. Altogether 67% of the bacteria produced indoleacetic acid (IAA), a plant growth-promoting phytohormone. The concentration of IAA produced by 53 isolates was higher than 20 µg ml−1. In total 21% of the bacteria produced siderophore (5.50–167.67 µg ml−1) with two Bacillus sp. producing more than 100 µg ml−1. Eighteen isolates produced both IAA and siderophore. The results suggested that the indigenous bacteria in the soil have beneficial characteristics for remediating the contaminated mine tailing soil. PMID:25188470

  6. Culturable heavy metal-resistant and plant growth promoting bacteria in V-Ti magnetite mine tailing soil from Panzhihua, China.

    PubMed

    Yu, Xiumei; Li, Yanmei; Zhang, Chu; Liu, Huiying; Liu, Jin; Zheng, Wenwen; Kang, Xia; Leng, Xuejun; Zhao, Ke; Gu, Yunfu; Zhang, Xiaoping; Xiang, Quanju; Chen, Qiang

    2014-01-01

    To provide a basis for using indigenous bacteria for bioremediation of heavy metal contaminated soil, the heavy metal resistance and plant growth-promoting activity of 136 isolates from V-Ti magnetite mine tailing soil were systematically analyzed. Among the 13 identified bacterial genera, the most abundant genus was Bacillus (79 isolates) out of which 32 represented B. subtilis and 14 B. pumilus, followed by Rhizobium sp. (29 isolates) and Ochrobactrum intermedium (13 isolates). Altogether 93 isolates tolerated the highest concentration (1000 mg kg(-1)) of at least one of the six tested heavy metals. Five strains were tolerant against all the tested heavy metals, 71 strains tolerated 1,000 mg kg(-1) cadmium whereas only one strain tolerated 1,000 mg kg(-1) cobalt. Altogether 67% of the bacteria produced indoleacetic acid (IAA), a plant growth-promoting phytohormone. The concentration of IAA produced by 53 isolates was higher than 20 µg ml(-1). In total 21% of the bacteria produced siderophore (5.50-167.67 µg ml(-1)) with two Bacillus sp. producing more than 100 µg ml(-1). Eighteen isolates produced both IAA and siderophore. The results suggested that the indigenous bacteria in the soil have beneficial characteristics for remediating the contaminated mine tailing soil.

  7. 2-Hydroxy Acids in Plant Metabolism

    PubMed Central

    Maurino, Veronica G.; Engqvist, Martin K. M.

    2015-01-01

    Glycolate, malate, lactate, and 2-hydroxyglutarate are important 2-hydroxy acids (2HA) in plant metabolism. Most of them can be found as D- and L-stereoisomers. These 2HA play an integral role in plant primary metabolism, where they are involved in fundamental pathways such as photorespiration, tricarboxylic acid cycle, glyoxylate cycle, methylglyoxal pathway, and lysine catabolism. Recent molecular studies in Arabidopsis thaliana have helped elucidate the participation of these 2HA in in plant metabolism and physiology. In this chapter, we summarize the current knowledge about the metabolic pathways and cellular processes in which they are involved, focusing on the proteins that participate in their metabolism and cellular/intracellular transport in Arabidopsis. PMID:26380567

  8. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank; Boddupalli, Sekhar S.

    2011-08-23

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  9. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank; Boddupalli, Sekhar S.

    2005-08-30

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  10. Migration of acidic groundwater seepage from uranium-tailings impoundments, 1. Field study and conceptual hydrogeochemical model

    NASA Astrophysics Data System (ADS)

    Morin, Kevin A.; Cherry, John A.; Dave, Nand K.; Lim, Tjoe P.; Vivyurka, Al J.

    1988-08-01

    In this first paper of a series, the results of a study at a non-operational tailings site are presented and are used to construct a general conceptual model for seepage migration from uranium-tailings impoundments. Many parts of the model are applicable to other types of tailings and to acid drainage in general. At the field site, the impoundment lies over a portion of a glaciofluvial sand aquifer. Tailings seepage drains downward into the aquifer and then migrates laterally away. Results of the field study indicate the seepage can be divided into three geochemical zones: (1) the inner core, which is essentially unaltered, acidic seepage from the tailings; (2) the neutralization zone, in which inner-core water is neutralized and aqueous concentrations decrease significantly; and (3) the outer zone, which contains both neutralized water from the neutralization zone and pH-neutral process water from the uranium milling operation. Yearly comparisons from 1979 to 1984 indicate the neutralization zone and inner core are migrating downgradient at a rate of about 1 meter/year, which is about 1/440 of the groundwater velocity. The mechanisms that produce the retardation and the decreases in aqueous concentrations are part of the conceptual model. The main features of the conceptual model are solid-liquid interactions, particularly mineral precipitation-dissolution, and buffering effects of dominant aqueous species. The important minerals undergoing precipitation-dissolution are the calcite-siderite solid solution, gypsum, Al-OH minerals, and Fe-OH minerals. "Cell and streamtube" calculations are used to evaluate the general trends in aqueous concentrations and to assist in explaining observed migration rates. Co-precipitation with the above minerals apparently accounts for decreases in other major, minor, and metal solutes. Because of the large amount of mineral precipitation and co-precipitation, variations in 2H and 18O were observed over a flow distance of several

  11. Soil acidity determines the effectiveness of an organic amendment and a native bacterium for increasing soil stabilisation in semiarid mine tailings.

    PubMed

    Carrasco, L; Caravaca, F; Azcón, R; Roldán, A

    2009-01-01

    Unstable mine tailings are vulnerable to water and air erosion, so it is important to promote their surface stabilisation in order to avoid the spread of heavy metals. In a greenhouse experiment, we assessed the effect of the addition of Aspergillus niger-treated sugar beet waste and inoculation with a native bacterium, Bacillus cereus, on the stabilisation of soil aggregates of two acidic, semiarid mine tailings, with different acidity degree, during watering and drying periods. Organic amendment raised the pH of both the moderately and highly acidic tailings, whereas the bacterial inoculation increased this parameter in the former. Only the amendment addition increased soil water-soluble carbon in both tailings compared with their controls, under either watering or drying conditions. Both the amendment and B. cereus enhanced water-soluble carbohydrates. Both treatments increased dehydrogenase activity and aggregate stability, particularly in the moderately acidic tailing under drying conditions. After soil drying, aggregate stability was increased by the amendment (about 66% higher than the control soil) and by the bacterium (about 45% higher than the control soil) in the moderately acidic tailing. The effectiveness of these treatments as structure-stabilisation methods for degraded, semiarid mine ecosystems appears to be restricted to tailings of moderate acidity.

  12. Evolution of soil properties and metals in acid and alkaline mine tailing ponds after amendments and microorganisms application

    NASA Astrophysics Data System (ADS)

    Acosta, Jose A.; Faz, Ángel; Zornoza, Raúl; Martínez-Martínez, Silvia; Bech, Jaume

    2015-04-01

    Intense mining activities in the past were carried out in Cartagena-La Unión mining district, SE Spain, and caused excessive accumulation of toxic metals in tailing ponds which poses a high environmental and ecological risk. One of the remediation options gaining considerable interest in recent years is the in situ immobilization of metals. A corresponding reduction in the plant-available metal fraction allows re-vegetation and ecosystem restoration of the heavily contaminated sites. In addition, the use of microorganisms to improve the soil condition is a new tool used to increase spontaneous plant colonization. The aim of this research was to assess the effect of amendments (pig manure, sewage sludge, and lime) and microorganisms on the evolution of soil properties and metals in acid and alkaline tailing ponds and to evaluate the content of metals in Zygophylum fabago one year after amendments application. The study was carried out in two mine ponds (acid and alkaline). Twenty seven square field plots, each one consisting of 4 m2, were located in each pond. Four different doses of microorganism (EM) (0 ml, 20 ml, 100 ml and 200 ml of microorganism solution in each plot) and one dose of pig manure (5 kg per plot), sewage sludge (4 kg per plot) and lime (22 kg per plot) were used. Organic amendment doses were calculated according to European nitrogen legislations, and lime dose was calculated according with the potential acid production through total sulphur oxidation. Three replicates of each treatment (organic amendment + lime + microorganism dose 0, 1, 2, or 3) and control soil (with no amendments) were carried out. Plots were left to the semi-arid climate conditions after the addition of amendments to simulate real potential applications of the results. Soil samples was collected every 4 month from each plot during one year, after this time Zygophylum fabago plants were sampled from each plots. Soil properties including: pH, salinity, total, inorganic and

  13. Biotransformation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid by plant cell cultures of Eucalyptus perriniana.

    PubMed

    Katsuragi, Hisashi; Shimoda, Kei; Kubota, Naoji; Nakajima, Nobuyoshi; Hamada, Hatsuyuki; Hamada, Hiroki

    2010-01-01

    Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.

  14. An assessment of plant biointrusion at the Uranium Mill Tailings Remedial Action Project rock-covered disposal cells

    SciTech Connect

    Not Available

    1990-10-01

    This study is one of a number of special studies that have been conducted regarding various aspects of the Uranium Mill Tailings Remedial Action (UMTRA) Project. This special study was proposed following routine surveillance and maintenance surveys and observations reported in a special study of vegetative covers (DOE, 1988), in which plants were observed growing up through the rock erosion layer at recently completed disposal cells. Some of the plants observed were deep-rooted woody species, and questions concerning root intrusion into disposal cells and the need to control plant growth were raised. The special study discussed in this report was designed to address some of the ramifications of plant growth on disposal cells that have rock covers. The NRC has chosen rock covers over vegetative covers in the arid western United States because licenses cannot substantiate that the vegetative covers will be significantly greater than 30 percent and preferably 70 percent,'' which is the amount of vegetation required to reduce flow to a point of stability.'' The potential impacts of vegetation growing in rock covers are not addressed by the NRC (1990). The objectives, then, of this study were to determine the species of plants growing on two rock-covered disposal cells, study the rooting pattern of plants on these cells, and identify possible impacts of plant root penetration on these and other UMTRA Project rock-covered cells.

  15. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants.

  16. Fact Sheet - Phosphate Fertilizer Production Plants and Phosphoric Acid Manufacturing Plants NESHAP

    EPA Pesticide Factsheets

    Fact sheet summarizing National Emission Standards for Hazardous Air Pollutants (NESHAP) for Phosphate Fertilizer Production Plants and Phosphoric Acid Manufacturing Plants (40 CFR 63 Subparts AA and BB).

  17. Determination of thermodynamic and transport parameters of naphthenic acids and organic process chemicals in oil sand tailings pond water.

    PubMed

    Wang, Xiaomeng; Robinson, Lisa; Wen, Qing; Kasperski, Kim L

    2013-07-01

    Oil sand tailings pond water contains naphthenic acids and process chemicals (e.g., alkyl sulphates, quaternary ammonium compounds, and alkylphenol ethoxylates). These chemicals are toxic and can seep through the foundation of the tailings pond to the subsurface, potentially affecting the quality of groundwater. As a result, it is important to measure the thermodynamic and transport parameters of these chemicals in order to study the transport behavior of contaminants through the foundation as well as underground. In this study, batch adsorption studies and column experiments were performed. It was found that the transport parameters of these chemicals are related to their molecular structures and other properties. The computer program (CXTFIT) was used to further evaluate the transport process in the column experiments. The results from this study show that the transport of naphthenic acids in a glass column is an equilibrium process while the transport of process chemicals seems to be a non-equilibrium process. At the end of this paper we present a real-world case study in which the transport of the contaminants through the foundation of an external tailings pond is calculated using the lab-measured data. The results show that long-term groundwater monitoring of contaminant transport at the oil sand mining site may be necessary to avoid chemicals from reaching any nearby receptors.

  18. The Effect of Lactic Acid Bacteria-fermented Soybean Milk Products on Carrageenan-induced Tail Thrombosis in Rats

    PubMed Central

    KAMIYA, Seitaro; OGASAWARA, Masayoshi; ARAKAWA, Masayuki; HAGIMORI, Masayori

    2013-01-01

    Thrombosis is characterized by congenital and acquired procatarxis. Lactic acid bacteria-fermented soybean milk products (FS-LAB) inhibit hepatic lipid accumulation and prevent atherosclerotic plaque formation. However, the therapeutic efficacy of FS-LAB against thrombosis has yet to be investigated. In this study, FS-LAB were administered subcutaneously into the tails of rats, with the subsequent intravenous administration of κ-carrageenan 12 hr after the initial injection. In general, administration of κ-carrageenan induces thrombosis. The length of the infarcted tail regions was significantly shorter in the rats administered a single-fold or double-fold concentration of the FS-LAB solution compared with the region in control rats. Therefore, FS-LAB exhibited significant antithrombotic effects. Our study is the first to characterize the properties of FS-LAB and, by testing their efficacy on an in vivo rat model of thrombosis, demonstrate the potency of their antithrombotic effect. PMID:24936368

  19. Community-level impacts of white-tailed deer on understorey plants in North American forests: a meta-analysis.

    PubMed

    Habeck, Christopher W; Schultz, Alexis K

    2015-10-20

    The impacts of introduced or overabundant large herbivores are a concern for the conservation of forest plant communities and the sustainability of ecosystem function. White-tailed deer (Odocoileus virginianus) are considered ecologically overabundant in much of North America. Previous work suggests that impacts of deer overabundance are broadly negative and are consequently degrading forests at multiple ecological and taxonomic levels. However, no quantitative synthesis currently exists to verify the generality or magnitude of these impacts. Here, we report the results of a meta-analysis quantifying the effects of deer exclusion on the diversity, cover and abundance of woody, herbaceous and whole community components of forest understories in North America. In addition, we explore the relationships of environmental and experimental factors on the direction and magnitude of plant community outcomes using meta-regression. Using 119 calculated effect sizes sourced from 25 peer-reviewed articles, we constructed 10 community-specific data sets and found strongly positive diversity, cover and abundance responses of the woody community to deer exclusion, but no significant effects for the herbaceous or whole community components of forest understories. Local deer density and time since exclusion were significant moderators of both whole community and woody community richness. Local deer density also moderated the effects of deer exclusion on whole community cover. Plot area, in contrast, showed no relationship to any of the community response outcomes. We suggest that the use of inadequate diversity indices, non-native species replacement or legacy effects of chronic deer overabundance might explain why the herbaceous and whole community components of forest understories showed no diversity or cover responses to deer exclusion. We also suggest some strategies to increase opportunities for future quantitative syntheses of deer impacts on forests, including providing

  20. Community-level impacts of white-tailed deer on understorey plants in North American forests: a meta-analysis

    PubMed Central

    Habeck, Christopher W.; Schultz, Alexis K.

    2015-01-01

    The impacts of introduced or overabundant large herbivores are a concern for the conservation of forest plant communities and the sustainability of ecosystem function. White-tailed deer (Odocoileus virginianus) are considered ecologically overabundant in much of North America. Previous work suggests that impacts of deer overabundance are broadly negative and are consequently degrading forests at multiple ecological and taxonomic levels. However, no quantitative synthesis currently exists to verify the generality or magnitude of these impacts. Here, we report the results of a meta-analysis quantifying the effects of deer exclusion on the diversity, cover and abundance of woody, herbaceous and whole community components of forest understories in North America. In addition, we explore the relationships of environmental and experimental factors on the direction and magnitude of plant community outcomes using meta-regression. Using 119 calculated effect sizes sourced from 25 peer-reviewed articles, we constructed 10 community-specific data sets and found strongly positive diversity, cover and abundance responses of the woody community to deer exclusion, but no significant effects for the herbaceous or whole community components of forest understories. Local deer density and time since exclusion were significant moderators of both whole community and woody community richness. Local deer density also moderated the effects of deer exclusion on whole community cover. Plot area, in contrast, showed no relationship to any of the community response outcomes. We suggest that the use of inadequate diversity indices, non-native species replacement or legacy effects of chronic deer overabundance might explain why the herbaceous and whole community components of forest understories showed no diversity or cover responses to deer exclusion. We also suggest some strategies to increase opportunities for future quantitative syntheses of deer impacts on forests, including providing

  1. Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants

    DOEpatents

    Ohlrogge, John B.; Cahoon, Edgar B.; Shanklin, John; Somerville, Christopher R.

    1995-01-01

    The present invention relates to a process for producing lipids containing the fatty acid petroselinic acid in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a .omega.12 desaturase from another species which does normally accumulate petroselinic acid.

  2. Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants

    DOEpatents

    Ohlrogge, J.B.; Cahoon, E.B.; Shanklin, J.; Somerville, C.R.

    1995-07-04

    The present invention relates to a process for producing lipids containing the fatty acid, petroselinic acid, in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a {omega}12 desaturase from another species which does normally accumulate petroselinic acid. 19 figs.

  3. DC resistivity and IP methods in acid mine drainage problems: results from the Copper Cliff mine tailings impoundments

    NASA Astrophysics Data System (ADS)

    Yuval, Douglas; Oldenburg, W.

    1996-04-01

    Oxidation of sulfide minerals in the mine tailings impoundments at Copper Cliff, Ontario generates acidic conditions and elevated concentrations of dissolved metals and sulfates in the pore water. The pore water migrates away from the tailings to pose a potential environmental hazard if is should reach nearby water systems. There is a need to characterize this potential environmental problem and to assess the future hazards. A combined DC resistivity and induced polarization (IP) survey was carried out along one of the major flowpaths in the tailings and the data were inverted to produce detailed electrical conductivity and chargeability structures of the cross-section below the survey line. The conductivity distributions are directly translated, through theoretical and empirical relations, to a map of the concentration of the total dissolved solids (TDS) along the cross-section and thereby provide insight about the in-situ pore water quality. The sulfide minerals are the source of the IP response and, thus, when combined with borehole data, the chargeability model can be used to estimate the amount and distribution of the sulfides.

  4. Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

    NASA Astrophysics Data System (ADS)

    Tozsin, Gulsen

    2016-01-01

    Acid mine drainage (AMD) with high concentrations of sulfates and metals is generated by the oxidation of sulfide bearing wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings (sulfide- bearing wastes) was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neutralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment ( t = 0). In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sulfate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) from AMD generated by copper flotation tailings.

  5. Long-term biobarriers to plant and animal intrusions of uranium tailings. [24% trifluralin, 18% carbon black, and 58% polymer

    SciTech Connect

    Cline, J.F.; Burton, F.G.; Cataldo, D.A.; Skiens, W.E.; Gano, K.A.

    1982-09-01

    The objective of this project was to develop and evaluate the effectiveness of physical and chemical barriers designed to prevent plant and animal breachment of uranium mill tailings containment systems for an extended period of time. A polymeric carrier/biocide delivery system was developed and tested in the laboratory, greenhouse and field. A continuous flow technique was established to determine the release rates of the biocides from the PCD systems; polymeric carrier specifications were established. Studies were conducted to determine effective biocide concentrations required to produce a phytotoxic response and the relative rates of phytotoxin degradation resulting from chemical and biological breakdown in soils. The final PCD system developed was a pelletized system containing 24% trifluralin, 18% carbon black and 58% polymer. Pellets were placed in the soil at the Grand Junction U-tailings site at one in. and two in. intervals. Data obtained in the field determined that the pellets released enough herbicide to the soil layer to stop root elongation past the barrier. Physical barriers to subsurface movement of burrowing animals were investigated. Small crushed stone (1 to 1 1/2 in. diameter) placed over asphalt emulsion and multilayer soil seals proved effective as barriers to a small mammal (ground squirrels) but were not of sufficient size to stop a larger animal (the prairie dog). No penetrations were made through the asphalt emulsion or the clay layer of the multilayer soil seals by either of the two mammals tested. A literature survey was prepared and published on the burrowing habits of the animals that may be found at U-tailings sites.

  6. Characterisation of fine-grained tailings from a marble processing plant and their acute effects on the copepod Calanus finmarchicus.

    PubMed

    Farkas, Julia; Altin, Dag; Hammer, Karen M; Hellstrøm, Kaja C; Booth, Andy M; Hansen, Bjørn Henrik

    2017-02-01

    Submarine tailing disposal (STD) of mining waste is practiced as an alternative to land fill disposal in several countries. Knowledge regarding the environmental implications of STD on fjord and other marine ecosystems, including the pelagic environment, is scarce. In this study, we characterised the particle shape, size and metal content of the fine-grained fraction of tailings (FGT) from a Norwegian marble processing plant and investigated their acute toxicity and impact on feeding rate in adult Calanus finmarchicus. Initial tailing dispersions with a concentration of 1 mg mL(-1) contained approximately 72 million particles, with 62% of particles between 0.6 and 1 μm in size. After a sedimentation time of 1 h, 69% of the particles between 0.6 and 5 μm remained dispersed, decreasing to 22% after 6 h. When subjected to low energy turbulence in exposure experiments, the formation of fragile agglomerates was observed. The FGT contained Al, Mn, Fe and Ni, with no detectable dissolution occurring during the 48 h exposure period. Acute exposure (up to 5 g L(-1)) to FGT caused no mortality in C. finmarchicus. Similarly, feeding rates determined during a 40 h depuration period, were not significantly impacted. However, surface attachment and uptake of FGT into the digestive tract of the copepods was observed. This indicates that, whilst marble FGT are not acutely toxic to copepods, chronic effects such as impacts on organism's energy budgets could occur, highlighting the need for further research on potential sublethal effects in organisms exposed to fine inorganic particles.

  7. Radon transport from uranium mill tailings via plant transpiration. Final report

    SciTech Connect

    Lewis, B.A.G.

    1985-01-01

    Radon exhalation by vegetation planted on bare or soil-covered uranium mill wastes was studied based on an assumption that radon transport from soil to atmosphere via plants takes place in the transpiration stream. Results show that radon exhalation by plants is inversely related to water transpired, primarily a dilution effect. Radon released appeared directly related to leaf area, suggesting that radon is carried into the plant by mass flow in water; however, once within the plant, radon very likely diffuses through the entire leaf cuticle, while water vapor diffuses primarily through open stomates. Application of a computerized model for water transpiration to radon exhalation is not immediately useful until the role of water in radon transport is defined throughout the continuum from rooting medium to the atmosphere. Until then, a simple calculation based on leaf area index and Ra-226 concentration in the rooting medium can provide an estimate of radon release from revegetated wastes containing radium.

  8. Crystallogenesis of bacteriophage P22 tail accessory factor gp26 at acidic and neutral pH

    SciTech Connect

    Cingolani, Gino Andrews, Dewan; Casjens, Sherwood

    2006-05-01

    The crystallogenesis of bacteriophage P22 tail-fiber gp26 is described. To study possible pH-induced conformational changes in gp26 structure, native trimeric gp26 has been crystallized at acidic pH (4.6) and a chimera of gp26 fused to maltose-binding protein (MBP-gp26) has been crystallized at neutral and alkaline pH (7-10). Gp26 is one of three phage P22-encoded tail accessory factors essential for stabilization of viral DNA within the mature capsid. In solution, gp26 exists as an extended triple-stranded coiled-coil protein which shares profound structural similarities with class I viral membrane-fusion protein. In the cryo-EM reconstruction of P22 tail extracted from mature virions, gp26 forms an ∼220 Å extended needle structure emanating from the neck of the tail, which is likely to be brought into contact with the cell’s outer membrane when the viral DNA-injection process is initiated. To shed light on the potential role of gp26 in cell-wall penetration and DNA injection, gp26 has been crystallized at acidic, neutral and alkaline pH. Crystals of native gp26 grown at pH 4.6 diffract X-rays to 2.0 Å resolution and belong to space group P2{sub 1}, with a dimer of trimeric gp26 molecules in the asymmetric unit. To study potential pH-induced conformational changes in the gp26 structure, a chimera of gp26 fused to maltose-binding protein (MBP-gp26) was generated. Hexagonal crystals of MBP-gp26 were obtained at neutral and alkaline pH using the high-throughput crystallization robot at the Hauptman–Woodward Medical Research Institute, Buffalo, NY, USA. These crystals diffract X-rays to beyond 2.0 Å resolution. Structural analysis of gp26 crystallized at acidic, neutral and alkaline pH is in progress.

  9. Effects of a chemical weapons incineration plant on red-tailed tropicbirds

    USGS Publications Warehouse

    Schreiber, E.A.; Doherty, P.F.; Schenk, G.A.

    2001-01-01

    From 1990 to 2000, the Johnston Atoll Chemical Agent Disposal System (JACADS) incinerated part of the U.S. stockpile of chemical weapons on Johnston Atoll, central Pacific Ocean, which also is a National Wildlife Refuge and home to approximately a half-million breeding seabirds. The effect on wildlife of incineration of these weapons is unknown. Using a multi-strata mark-recapture analysis, we investigated the effects of JACADS on reproductive success, survival, and movement probabilities of red-tailed tropicbirds (Phaethon rubricauda) nesting both downwind and upwind of the incineration site. We found no effect of chemical incineration on these tropicbird demographic parameters over the 8 years of our study. An additional 3 years of monitoring tropicbird demography will take place, post-incineration.

  10. Environmental Factors Influencing the Structural Dynamics of Soil Microbial Communities During Assisted Phytostabilization of Acid-Generating Mine Tailings: a Mesocosm Experiment

    PubMed Central

    Valentín-Vargas, Alexis; Root, Robert A.; Neilson, Julia W; Chorover, Jon; Maier, Raina M.

    2014-01-01

    Compost-assisted phytostabilization has recently emerged as a robust alternative for reclamation of metalliferous mine tailings. Previous studies suggest that root-associated microbes may be important for facilitating plant establishment on the tailings, yet little is known about the long-term dynamics of microbial communities during reclamation. A mechanistic understanding of microbial community dynamics in tailings ecosystems undergoing remediation is critical because these dynamics profoundly influence both the biogeochemical weathering of tailings and the sustainability of a plant cover. Here we monitor the dynamics of soil microbial communities (i.e. bacteria, fungi, archaea) during a 12-month mesocosm study that included 4 treatments: 2 unplanted controls (unamended and compost-amended tailings) and 2 compost-amended seeded tailings treatments. Bacterial, fungal and archaeal communities responded distinctively to the revegetation process and concurrent changes in environmental conditions and pore water chemistry. Compost addition significantly increased microbial diversity and had an immediate and relatively long-lasting buffering-effect on pH, allowing plants to germinate and thrive during the early stages of the experiment. However, the compost buffering capacity diminished after six months and acidification took over as the major factor affecting plant survival and microbial community structure. Immediate changes in bacterial communities were observed following plant establishment, whereas fungal communities showed a delayed response that apparently correlated with the pH decline. Fluctuations in cobalt pore water concentrations, in particular, had a significant effect on the structure of all three microbial groups, which may be linked to the role of cobalt in metal detoxification pathways. The present study represents, to our knowledge, the first documentation of the dynamics of the three major microbial groups during revegetation of compost

  11. [Tissue culture of medicinal plant and abscisic acid].

    PubMed

    Fang, Hui-Yong; Zhu, Hong; Yao, Jian-Xun; Jia, Cai-Feng; Shan, Gao-Wei; Li, Min-Hui

    2013-01-01

    Abscisic acid (ABA) plays a key role in many physiological processes of plants, and it was also applied to fields of medicinal plant biotechnology. The article presents a review of some recent application of ABA in enhancing the production of secondary metabolites of medicinal plants, improving the in vitro conservation in medicinal plant tissue culture system.

  12. TACN-based cationic lipids with amino acid backbone and double tails: materials for non-viral gene delivery.

    PubMed

    Wang, Bing; Yi, Wen-Jing; Zhang, Ji; Zhang, Qin-Fang; Xun, Miao-Miao; Yu, Xiao-Qi

    2014-04-01

    Cationic lipids have become an efficient type of non-viral vectors for gene delivery. In this Letter, four cationic lipids containing 1,4,7-triazacyclononane (TACN) headgroup, glutamic/aspartic acid backbone and dioleyl tails were designed and synthesized. The TACN headgroup gives these lipids excellent pH buffering capacities, which were higher than branched 25 kDa PEI. Cationic liposomes prepared from these lipids and DOPE showed good DNA affinity, and full DNA condensation was found at N/P ratio of 3 via agarose gel electrophoresis. The lipoplexes were characterized by dynamic light scattering (DLS) assay, which gave proper particle sizes and zeta-potentials for transfection. In vitro gene transfection results in two cell lines reveal that TAN (with aspartic acid and amide bond in the structure) shows the best transfection efficiency, which is close to commercially available transfection agent Lipofectamine 2000.

  13. In situ biodegradation of naphthenic acids in oil sands tailings pond water using indigenous algae-bacteria consortium.

    PubMed

    Mahdavi, Hamed; Prasad, Vinay; Liu, Yang; Ulrich, Ania C

    2015-01-01

    In this study, the biodegradation of total acid-extractable organics (TAOs), commonly called naphthenic acids (NAs), was investigated. An indigenous microbial culture containing algae and bacteria was taken from the surface of a tailings pond and incubated over the course of 120days. The influence of light, oxygen and the presence of indigenous algae and bacteria, and a diatom (Navicula pelliculosa) on the TAO removal rate were elucidated. The highest biodegradation rate was observed with bacteria growth only (without light exposure) with a half-life (t(1/2)) of 203days. The algae-bacteria consortium enhanced the detoxification process, however, bacterial biomass played the main role in toxicity reduction. Principal component analysis (PCA) conducted on FT-IR spectra, identified functional groups and bonds (representing potential markers for biotransformation of TAOs) as follows: hydroxyl, carboxyl and amide groups along with CH, arylH, arylOH and NH bonds.

  14. Alternative control techniques document: Nitric and adipic acid manufacturing plants

    SciTech Connect

    Lazzo, D.W.

    1991-12-01

    The Alternative Control Techniques document describes available control techniques for reducing NOx emission levels from nitric and adipic acid manufacturing plants. The document contains information on the formation of NOx and uncontrolled NOx emissions from nitric and adipic acid plants. The following NOx control techniques for nitric acid plants are discussed: extended absorption, nonselective catalytic reduction (NSCR), and selective catalytic reduction (SCR). The following NOx control techniques for adipic acid plants are discussed: extended absorption and thermal reduction. For each control technique, achievable controlled NOx emission levels, capital and annual costs, cost effectiveness, and environmental and energy impacts are presented.

  15. [Chicoric and chlorogenic acids in various plants growing in Georgia].

    PubMed

    Chkhikvishvili, I D; Kharebava, G I

    2001-01-01

    Chicoric acid was isolated from dandelion (Taraxacum officinale Wigg.) leaves by column chromatography. Conditions for HPLC analysis of chicoric and chlorogenic acids were optimized. These acids were assayed in some plants growing in Georgia. The optimum conservation temperature for the preservation of chicoric and chlorogenic acids in leaves of dandelion and bilberry (Vaccinium arctostaphylos L.) was determined.

  16. 75 FR 9377 - Endangered and Threatened Wildlife and Plants; Listing the Flat-Tailed Horned Lizard as Threatened

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... Flat- Tailed Horned Lizard as Threatened AGENCY: Fish and Wildlife Service, Interior. ACTION..., proposed rule to list the flat-tailed horned lizard (Phrynosoma mcallii) as threatened under the Endangered..., 1993 (58 FR 62624), to list the flat-tailed horned lizard as a threatened species, and reopens...

  17. Enumeration of Thiobacilli within pH-Neutral and Acidic Mine Tailings and Their Role in the Development of Secondary Mineral Soil

    PubMed Central

    Southam, G.; Beveridge, T. J.

    1992-01-01

    The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicates, pyrite, chalcopyrite, and sphalerite. These tailings are colonized by an active population of Thiobacillus ferrooxidans which is localized to an acid zone occupying 40% of the tailings' surface. This population peaked at 7 × 108 most probable number per gram of tailings during July and August 1990 and extended to a depth of 40 cm from the surface. Examination of samples over this depth profile by transmission electron microscopy and electron dispersive spectroscopy revealed a microbially mediated mineral transition from sulfides (below 40 cm) to chlorides and phosphates (at the surface). Silicate minerals were unaltered by microbial action. Transmission electron microscopy showed a tight association between Thiobacillus species and the sulfide minerals, which helps account for their prominence in tailings environments. Accurate enumeration of T. ferrooxidans from tailings required the disruption of their bonding to the mineral interface. Vortexing of a 10% aqueous suspension of the tailings material prior to most-probable-number analysis best facilitated this release. Even though heavy metals were highly mobile under acidic conditions at the Lemoine tailings, it was evident by transmission electron microscopy and electron dispersive spectroscopy that they were being immobilized as bona fide fine-grain minerals containing iron, copper, chlorine, phosphorus, and oxygen on bacterial surfaces and exopolymers. This biomineralization increased with increasing bacterial numbers and was most evident in the upper 3 cm of the acidic zone. Images PMID:16348721

  18. Determination of acid forming potential of massive sulfide minerals and the tailings situated in lead/zinc mining district of Balya (NW Turkey)

    NASA Astrophysics Data System (ADS)

    Çelebi, E. Ender; Öncel, M. Salim

    2016-12-01

    Weathering of sulfide minerals is a major source of acid production in nature and especially in mining territories. Pyrite is not the only principal mineral that generates acid drainage: other sulfide minerals (sphalerite, galena, chalcopyrite, etc.) may also be responsible for acid production. In addition to massive sulfide minerals, sulfide-bearing mine tailings may also produce acid drainage due to oxidation and hydrolysis reactions in waste dumps. The lead/zinc (Pb/Zn) mining region in Balya and Balıkesir, in Turkey, has operated mines intensively since the 1860s; so that characterization of the sulfide minerals and tailings situated and formed around the mining site is of great importance to secure a sustainable environment. For this purpose, acid production and neutralization potentials of massive sulfide ores of the region, and in the Pb/Zn process facility mine tailings from ten different points of tailings dam, have been determined by applied conventional Acid-Base Accounting (ABA) and Net Acid Generation (NAG) static tests after chemical and mineralogical analysis. The NAG pH and net acid production potential (NAPP) values were compared on a chart in order to classify the samples as either acid generating or non-acid generating. According to the comparisons, the sulfide minerals were classified as potentially acid forming (PAF). Massive pyrite had the highest NAPP and NAG pH value of 1966.6 kg H2SO4/ton and 1.91, respectively and the galena had the lowest NAPP value of 558.9 kg H2SO4/ton. However, the sphalerite NAG leachate pH value of 4.30 was the highest in sulfide minerals so that the sphalerite plotted near the uncertainty reference border in the PAF zone. In the mine tailings, NAPP values of 105.9 kg H2SO4/ton on average and the NAG pH values of over 7.5 were determined. In addition to these tests, water leaching (agitation test) was carried out on tailings in order to generate more information. The tailings did not generate acidic leachates as

  19. Lead sulfate nano- and microparticles in the acid plant blow-down generated at the sulfuric acid plant of the El Teniente mine, Chile.

    PubMed

    Barassi, Giancarlo M; Klimsa, Martin; Borrmann, Thomas; Cairns, Mathew J; Kinkel, Joachim; Valenzuela, Fernando

    2014-12-01

    The acid plant 'blow-down' (also called weak acid) produced at El Teniente mine in Chile was characterized. This liquid waste (tailing) is generated during the cooling and cleaning of the smelter gas prior to the production of sulfuric acid. The weak acid was composed of a liquid and a solid phase (suspended solids). The liquid phase of the sample analyzed in this study mainly contained Cu (562 mg L(-1)), SO4(2-) (32 800 mg L(-1)), Ca (1449 mg L(-1)), Fe (185 mg L(-1)), As (6 mg L(-1)), K (467 mg L(-1)) and Al (113 mg L(-1)). Additionally, the sample had a pH-value and total acidity of 0.45 and 2970 mg L(-1) as CaCO3, respectively. Hence, this waste was classified as extremely acidic and with a high metal content following the Ficklin diagram classification. Elemental analysis using atomic absorption, inductively coupled plasma, X-ray diffraction and electron microscopy showed that the suspended solids were anglesite (PbSO4) nano- and microparticles ranging from 50 nm to 500 nm in diameter.

  20. Synthesis of stereoarray isotope labeled (SAIL) lysine via the "head-to-tail" conversion of SAIL glutamic acid.

    PubMed

    Terauchi, Tsutomu; Kamikawai, Tomoe; Vinogradov, Maxim G; Starodubtseva, Eugenia V; Takeda, Mitsuhiro; Kainosho, Masatsune

    2011-01-07

    A stereoarray isotope labeled (SAIL) lysine, (2S,3R,4R,5S,6R)-[3,4,5,6-(2)H(4);1,2,3,4,5,6-(13)C(6);2,6-(15)N(2)]lysine, was synthesized by the "head-to-tail" conversion of SAIL-Glu, (2S,3S,4R)-[3,4-(2)H(2);1,2,3,4,5-(13)C(5);2-(15)N]glutamic acid, with high stereospecificities for all five chiral centers. With the SAIL-Lys in hand, the unambiguous simultaneous stereospecific assignments were able to be established for each of the prochiral protons within the four methylene groups of the Lys side chains in proteins.

  1. Dephosphorylation of microtubule-binding sites at the neurofilament-H tail domain by alkaline, acid, and protein phosphatases.

    PubMed

    Hisanaga, S; Yasugawa, S; Yamakawa, T; Miyamoto, E; Ikebe, M; Uchiyama, M; Kishimoto, T

    1993-06-01

    The dephosphorylation-induced interaction of neurofilaments (NFs) with microtubules (MTs) was investigated by using several phosphatases. Escherichia coli alkaline and wheat germ acid phosphatases increased the electrophoretic mobility of NF-H and NF-M by dephosphorylation, and induced the binding of NF-H to MTs. The binding of NFs to MTs was observed only after the electrophoretic mobility of NF-H approached the exhaustively dephosphorylated level when alkaline phosphatase was used. The number of phosphate remaining when NF-H began to bind to MTs was estimated by measuring phosphate bound to NF-H. NF-H did not bind to MTs even when about 40 phosphates from the total of 51 had been removed by alkaline phosphatase. The removal of 6 further phosphates finally resulted in the association of NF-H with MTs. A similar finding, that the restricted phosphorylation sites in the NF-H tail domain, but not the total amount of phosphates, were important for binding to MTs, was also obtained with acid phosphatases. In contrast to alkaline and acid phosphatases, four classes of protein phosphatases (protein phosphatases 1, 2A, 2B, and 2C) were ineffective for shifting the electrophoretic mobility of NF proteins and for inducing the association of NFs to MTs.

  2. Effect of succinic acid monoethyl ester on hemoglobin glycation and tail tendon collagen properties in type 2 diabetic rats.

    PubMed

    Saravanan, Ramalingam; Pari, Leelavinothan

    2008-06-01

    Succinic acid monoethyl ester (EMS) was recently proposed as an insulinotropic agent for the treatment of type 2 diabetes. The aim of the study was to investigate the effect of EMS and metformin administration on tail collagen content and its characteristics in streptozotocin-nicotinamide-induced type 2 diabetic rats. EMS was administered intraperitoneally for 30 days to normal and diabetic rats. In the diabetic rats, a significant increase in the levels of glucose, glycated hemoglobin, hydroxyproline, collagen content, extent glycation, fluorescence, neutral salt, acid and pepsin soluble collagen content was absorbed with a significant decrease in the level of insulin, hemoglobin in streptozotocin-nicotinamide diabetic rats. Moreover, a daily administration of nonglucidic nutrient EMS and metformin significantly decreased the levels of glucose, glycated hemoglobin, hydroxyproline, collagen content, extent glycation, fluorescence, neutral salt, acid and pepsin soluble collagen content, whereas it increased insulin, hemoglobin levels in diabetic rats. The positive influence of nonglucidic nutrient on both collagen content and its properties suggests a potential mechanism for the ability of EMS to delay diabetic complications.

  3. REE, Uranium (U) and Thorium (Th) contents in Betula pendula leaf growing around Komsomolsk gold concentration plant tailing (Kemerovo region, Western Siberia, Russia)

    NASA Astrophysics Data System (ADS)

    Yusupov, D. V.; Karpenko, Yu A.

    2016-09-01

    The article deals with the research findings of peculiarities of REE, Uranium and Thorium distribution in the territory surrounding the tailing of former Komsomolsk gold concentration plant according to the data from Betula pendula leaf testing. In the leaf element composition the slight deficiency of MREE and substantial excess of HREE are presented. In the nearest impacted area around the tailing, La, Yb, U and Th content, and Th/U ratio are lower than in the distant buffer area. It is shown, that value of Th/U ratio and REE can be an indicator for geochemical transformations of technogenic landscapes in mining districts. The results of the research can be used for biomonitoring of the territory around the tailing.

  4. Structure and Mechanism of Dimer-Monomer Transition of a Plant Poly(A)-Binding Protein upon RNA Interaction: Insights into Its Poly(A) Tail Assembly.

    PubMed

    Domingues, Mariane Noronha; Sforça, Mauricio Luis; Soprano, Adriana Santos; Lee, Jack; Souza, Tatiana de Arruda Campos Brasil de; Cassago, Alexandre; Portugal, Rodrigo Villares; Zeri, Ana Carolina de Mattos; Murakami, Mario Tyago; Sadanandom, Ari; Oliveira, Paulo Sergio Lopes de; Benedetti, Celso Eduardo

    2015-07-31

    Poly(A)-binding proteins (PABPs) play crucial roles in mRNA biogenesis, stability, transport and translational control in most eukaryotic cells. Although animal PABPs are well-studied proteins, the biological role, three-dimensional structure and RNA-binding mode of plant PABPs remain largely uncharacterized. Here, we report the structural features and RNA-binding mode of a Citrus sinensis PABP (CsPABPN1). CsPABPN1 has a domain architecture of nuclear PABPs (PABPNs) with a single RNA recognition motif (RRM) flanked by an acidic N-terminus and a GRPF-rich C-terminus. The RRM domain of CsPABPN1 displays virtually the same three-dimensional structure and poly(A)-binding mode of animal PABPNs. However, while the CsPABPN1 RRM domain specifically binds poly(A), the full-length protein also binds poly(U). CsPABPN1 localizes to the nucleus of plant cells and undergoes a dimer-monomer transition upon poly(A) interaction. We show that poly(A) binding by CsPABPN1 begins with the recognition of the RNA-binding sites RNP1 and RNP2, followed by interactions with residues of the β2 strands, which stabilize the dimer, thus leading to dimer dissociation. Like human PABPN1, CsPABPN1 also seems to form filaments in the presence of poly(A). Based on these data, we propose a structural model in which contiguous CsPABPN1 RRM monomers wrap around the RNA molecule creating a superhelical structure that could not only shield the poly(A) tail but also serve as a scaffold for the assembly of additional mRNA processing factors.

  5. Multi-component reactive transport modeling of natural attenuation of an acid groundwater plume at a uranium mill tailings site

    NASA Astrophysics Data System (ADS)

    Zhu, Chen; Hu, Fang Q.; Burden, David S.

    2001-11-01

    Natural attenuation of an acidic plume in the aquifer underneath a uranium mill tailings pond in Wyoming, USA was simulated using the multi-component reactive transport code PHREEQC. A one-dimensional model was constructed for the site and the model included advective-dispersive transport, aqueous speciation of 11 components, and precipitation-dissolution of six minerals. Transport simulation was performed for a reclamation scenario in which the source of acidic seepage will be terminated after 5 years and the plume will then be flushed by uncontaminated upgradient groundwater. Simulations show that successive pH buffer reactions with calcite, Al(OH) 3(a), and Fe(OH) 3(a) create distinct geochemical zones and most reactions occur at the boundaries of geochemical zones. The complex interplay of physical transport processes and chemical reactions produce multiple concentration waves. For SO 42- transport, the concentration waves are related to advection-dispersion, and gypsum precipitation and dissolution. Wave speeds from numerical simulations compare well to an analytical solution for wave propagation.

  6. Multi-component reactive transport modeling of natural attenuation of an acid groundwater plume at a uranium mill tailings site.

    PubMed

    Zhu, C; Hu, F Q; Burden, D S

    2001-11-01

    Natural attenuation of an acidic plume in the aquifer underneath a uranium mill tailings pond in Wyoming, USA was simulated using the multi-component reactive transport code PHREEQC. A one-dimensional model was constructed for the site and the model included advective-dispersive transport, aqueous speciation of 11 components, and precipitation-dissolution of six minerals. Transport simulation was performed for a reclamation scenario in which the source of acidic seepage will be terminated after 5 years and the plume will then be flushed by uncontaminated upgradient groundwater. Simulations show that successive pH buffer reactions with calcite, Al(OH)3(a), and Fe(OH)3(a) create distinct geochemical zones and most reactions occur at the boundaries of geochemical zones. The complex interplay of physical transport processes and chemical reactions produce multiple concentration waves. For SO4(2-) transport, the concentration waves are related to advection-dispersion, and gypsum precipitation and dissolution. Wave speeds from numerical simulations compare well to an analytical solution for wave propagation.

  7. Uptake of radium-226 from uranium mill tailing by C-3 and C-4 plants and implications for transport of radium-226 and radon-222 into the disposal-site environment

    SciTech Connect

    MacDonell, M.M.

    1986-01-01

    Radium-226 entry into plants grown on uranium mill tailings at pH 6.5 appears to be governed primarily by movement of tailings solution into the plant. The lower transpiration ratios of C-4 photosynthetic plants as compared to C-3 plants result in lower tissue concentrations of radium-225. In each case, the distribution of radium-226 within the plants studied: corn (C-4), dwarf sunflower (C-3), tall fescue grass (C-3), and four species of Panicum (two C-3 and two C-4) exhibited an acropetal gradient, decreasing from the roots where the concentrations are relatively high to the apex of the plant. Tissue concentrations of Ra-226 decreased over time, attributable to increases in biomass while total Ra-226 levels remain constant. Release of radon from vegetated tailings was found to be directly related to the total leaf area of the plant following introduction into the plant of tailings solution. Thus, the plant pathway is shown to be an important mechanism for the transport of radium-226 and radon-222 from mill tailings into the environment. Current tailings disposal site reclamation efforts should consider the effects of the photosynthetic nature of the vegetation species and its total leaf area to reduce the potential for introduction of these elements into the site environment.

  8. The effects of black-tailed prairie dogs on plant communities within a complex urban landscape: an ecological surprise?

    PubMed

    Beals, Stower C; Hartley, Laurel M; Prevéy, Janet S; Seastedt, Timothy R

    2014-05-01

    Historically, prairie dogs (Cynomys spp.) have been considered essential keystone species of western United States grassland ecosystems because they provide unique services and increase vegetation community richness, evenness, and diversity. However, the effects of black-tailed prairie dogs (Cynomys ludovicianus) on lands adjacent to or surrounded by urban areas may not result in the same ecosystem benefits historically associated with their presence. An urban landscape presents prairie dogs with movement challenges unparalleled in natural landscapes, as well as suites of nonnative plant species that are more common in disturbed areas. This study examined a complex ecosystem where vegetation communities are being influenced by directional environmental change, and quantified the synergistic effects resulting from the protective management of a native keystone species. The data set for this analysis was comprised of 71 paired (occupied by prairie dogs vs. unoccupied) vegetation surveys and 156 additional unpaired surveys collected from around the city of Boulder, Colorado, USA for 14 yr. Linear mixed models were used to compare data from transects occupied and unoccupied by prairie dogs, as well as to evaluate the effect of prairie dog occupation duration. In the absence of prairie dogs, vegetation in this region exhibited declines in native grasses, no changes in introduced grasses, and increases in native and nonnative forbs and bare soil over the study interval. In the presence of prairie dogs, these observed directional changes were nearly all amplified at rates four to 10 times greater than when prairie dogs were absent. Areas in Boulder occupied by prairie dogs also had significantly lower richness, evenness, and diversity of plant species, compared to unoccupied areas. Analysis of plant functional groups revealed the significant reduction of perennial native grasses, as well as a significantly higher cover of introduced forbs in occupied areas. Prairie dogs

  9. Seed dispersal by white-tailed deer: implications for long-distance dispersal, invasion, and migration of plants in eastern North America.

    PubMed

    Myers, Jonathan A; Vellend, Mark; Gardescu, Sana; Marks, P L

    2004-03-01

    For many plant species in eastern North America, short observed seed dispersal distances (ranging up to a few tens of meters) fail to explain rapid rates of invasion and migration. This discrepancy points to a substantial gap in our knowledge of the mechanisms by which seeds are dispersed long distances. We investigated the potential for white-tailed deer ( Odocoileus virginianus Zimm.), the dominant large herbivore in much of eastern North America, to disperse seeds via endozoochory. This is the first comprehensive study of seed dispersal by white-tailed deer, despite a vast body of research on other aspects of their ecology. More than 70 plant species germinated from deer feces collected over a 1-year period in central New York State, USA. Viable seeds included native and alien herbs, shrubs, and trees, including several invasive introduced species, from the full range of habitat types in the local flora. A mean of >30 seeds germinated per fecal pellet group, and seeds were dispersed during all months of the year. A wide variety of presumed dispersal modes were represented (endo- and exozoochory, wind, ballistic, ant, and unassisted). The majority were species with small-seeded fruits having no obvious adaptations for dispersal, underscoring the difficulty of inferring dispersal ability from diaspore morphology. Due to their broad diet, wide-ranging movements, and relatively long gut retention times, white-tailed deer have tremendous potential for effecting long-distance seed dispersal via ingestion and defecation. We conclude that white-tailed deer represent a significant and previously unappreciated vector of seed dispersal across the North American landscape, probably contributing an important long-distance component to the seed shadows of hundreds of plant species, and providing a mechanism to help explain rapid rates of plant migration.

  10. 77 FR 48433 - New Source Performance Standards Review for Nitric Acid Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... AGENCY 40 CFR Part 60 RIN 2060-AQ10 New Source Performance Standards Review for Nitric Acid Plants AGENCY... performance standards (NSPS) for nitric acid plants. Nitric acid plants include one or more nitric acid... standards for nitric acid plants, contact Mr. Nathan Topham, Sector Policies and Program Division, Office...

  11. Vegetation composition and ²²⁶Ra uptake by native plant species at a uranium mill tailings impoundment in South China.

    PubMed

    Hu, Nan; Ding, Dexin; Li, Guangyue; Zheng, Jifang; Li, Le; Zhao, Weichao; Wang, Yongdong

    2014-03-01

    A field investigation was conducted for the vegetation composition and (226)Ra uptake by native plant species at a uranium mill tailings impoundment in South China. 80 species belonging to 67 genera in 32 families were recorded in the sampling sites. The Poaceae and Asteraceae were the dominant families colonizing the impoundment. The number of the plant species and vegetation community composition in the sampling sites seemed most closely related to the activities of (226)Ra and the pH value of the uranium tailings. The plant species in the sampling sites with relatively low activities of (226)Ra and relatively high pH value formed a relatively stable vegetation community. The plant species in the sampling sites with medium activities of (226)Ra and medium pH value formed the transitional vegetation community. The plant species in the sampling sites with relatively high activities of (226)Ra and relatively low pH value formed a simple unstable vegetation community that was similar to that on the unused grassland. The activities of (226)Ra and transfer factors (TFs) varied greatly with the plant species. The high activities of (226)Ra and TFs were found in the leaves of Pteris multifida (150.6 Bq/g of AW; 9.131), Pteridium aquilinum (122.2 Bq/g of AW; 7.409), and Dryopteris scottii (105.7 Bq/g of AW; 6.408). They satisfied the criteria for a hyperaccumulator for (226)Ra. They may be the candidates for phytoremediation of (226)Ra in the uranium mill tailings impoundment areas and the contaminated soils around.

  12. Indole-3-acetic acid in plant-microbe interactions.

    PubMed

    Duca, Daiana; Lorv, Janet; Patten, Cheryl L; Rose, David; Glick, Bernard R

    2014-07-01

    Indole-3-acetic acid (IAA) is an important phytohormone with the capacity to control plant development in both beneficial and deleterious ways. The ability to synthesize IAA is an attribute that many bacteria including both plant growth-promoters and phytopathogens possess. There are three main pathways through which IAA is synthesized; the indole-3-pyruvic acid, indole-3-acetamide and indole-3-acetonitrile pathways. This chapter reviews the factors that effect the production of this phytohormone, the role of IAA in bacterial physiology and in plant-microbe interactions including phytostimulation and phytopathogenesis.

  13. Energy recovery method and system for combined sulphuric acid and phosphoric acid manufacturing plant

    SciTech Connect

    Cameron, G. M.; Orlando, J. V.

    1985-01-22

    In conventional processes for manufacturing phosphoric acid, sulphuric acid is reacted with phosphate rock to produce weak phosphoric acid which is concentrated using steam from the associated sulphuric acid manufacturing operation. Low grade heat from the absorbers and drier of the sulphuric acid manufacturing plant has been wasted. According to the invention waste heat from the drier and one or more absorbers of the sulphuric acid manufacturing plant is used in all the evaporators of the phosphoric acid plant. The evaporators all operate at low pressures and their heaters are arranged in series, to enable the heat to be used at the relatively low temperatures available. The valuable steam is thus freed for other uses.

  14. Metabolic Conversion of l-Ascorbic Acid to Oxalic Acid in Oxalate-accumulating Plants.

    PubMed

    Yang, J C; Loewus, F A

    1975-08-01

    l-Ascorbic acid-1-(14)C and its oxidation product, dehydro-l-ascorbic acid, produced labeled oxalic acid in oxalate-accumulating plants such as spinach seedlings (Spinacia oleracea) and the detached leaves of woodsorrel (Oxalis stricta and O. oregana), shamrock (Oxalis adenopylla), and begonia (Begonia evansiana). In O. oregana, conversion occurred equally well in the presence or absence of light. This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalic accumulation in plants.

  15. Metabolic Conversion of l-Ascorbic Acid to Oxalic Acid in Oxalate-accumulating Plants 1

    PubMed Central

    Yang, Joan C.; Loewus, Frank A.

    1975-01-01

    l-Ascorbic acid-1-14C and its oxidation product, dehydro-l-ascorbic acid, produced labeled oxalic acid in oxalate-accumulating plants such as spinach seedlings (Spinacia oleracea) and the detached leaves of woodsorrel (Oxalis stricta and O. oregana), shamrock (Oxalis adenopylla), and begonia (Begonia evansiana). In O. oregana, conversion occurred equally well in the presence or absence of light. This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalic accumulation in plants. PMID:16659288

  16. Application of organic acids for plant protection against phytopathogens.

    PubMed

    Morgunov, Igor G; Kamzolova, Svetlana V; Dedyukhina, Emilia G; Chistyakova, Tatiana I; Lunina, Julia N; Mironov, Alexey A; Stepanova, Nadezda N; Shemshura, Olga N; Vainshtein, Mikhail B

    2017-02-01

    The basic tendency in the field of plant protection concerns with reducing the use of pesticides and their replacement by environmentally acceptable biological preparations. The most promising approach to plant protection is application of microbial metabolites. In the last years, bactericidal, fungicidal, and nematodocidal activities were revealed for citric, succinic, α-ketoglutaric, palmitoleic, and other organic acids. It was shown that application of carboxylic acids resulted in acceleration of plant development and the yield increase. Of special interest is the use of arachidonic acid in very low concentrations as an inductor (elicitor) of protective functions in plants. The bottleneck in practical applications of these simple, nontoxic, and moderately priced preparations is the absence of industrial production of the mentioned organic acids of required quality since even small contaminations of synthetic preparations decrease their quality and make them dangerous for ecology and toxic for plants, animals, and human. This review gives a general conception on the use of organic acids for plant protection against the most dangerous pathogens and pests, as well as focuses on microbiological processes for production of these microbial metabolites of high quality from available, inexpensive, and renewable substrates.

  17. A collaborative effort to model plant response to acidic rain

    SciTech Connect

    Jacobson, J.; Irving, P.; Kuja, A.; Lee, J.; Shriner, D.; Troiano, J.; Perrigan, S.; Cullinan, V.

    1989-01-01

    Radish plants were exposed three times per week to simulated acidic rain at pH values of 2.6 to 5.4 over the course of four weeks in trials performed at Argonne, Illinois; Ithaca and Upton, New York; Corvallis, Oregon; Oak Ridge, Tennessee; and Toronto, Canada. Uniform genotype, soil media and planting techniques, treatment procedures, biological measurements, and experimental design were employed. Growth of plants differed among trials as a result of variation in greenhouse environmental conditions according to location and facilities. Larger plants underwent greater absolute but lower relative reductions in biomass after exposure to the higher levels of acidity. A generalized Mitscherlich function was used to model the effects of acidity of simulated rain on dry mass of hypocotyls using data from three laboratories that performed duplicate trials. The remaining data, from three other laboratories that performed only one trial each, were used to test the model. 14 refs., 2 figs., 7 tabs.

  18. Phosphoric acid, nitric acid, and hydrogen peroxide digestion of soil and plant materials for selenium determination

    SciTech Connect

    Dong, A.; Rendig, V.V.; Burau, R.G.; Besga, G.S.

    1987-11-15

    A mixture of phosphoric acid, nitric acid, and hydrogen peroxide has been proposed as an alternative to the use of the nitric/perchloric acid mixture to digest biological fluids to determine their selenium (Se) content. The purpose of the studies reported here was to test the applicability of this digestion method for the determination of Se in soil and plant materials.

  19. Soil Bacteria Take Up D-Amino Acids, Protect Plants

    NASA Astrophysics Data System (ADS)

    Sun, H. J.; Zhang, G.

    2011-12-01

    Recently, many groups reported D-amino acid uptake by plant roots, raising the question of whether soil D-amino acids represent a source of nitrogen or a source of toxicity. The discussion needs to be placed in the context of competition with rhizosphere bacteria. To provide this context, we followed the concentrations of D- and L-enantiomers of alanine, glutamic acid, aspartic acid, and leucine after they were added to soils in the laboratory. In all cases, the uptake of L-enantiomer began immediately and proceeded rapidly until exhausted. In contrast, the uptake of D-enantiomer required induction: an initial period of inactivity followed by rapid consumption comparable in rate to L-enantiomer. The induced nature of the D activity was confirmed by the addition of rifampicin, an mRNA synthesis inhibitor. Preventing the synthesis of new enzymes abolished soil flora's ability to consume D-amino acids, but not L-amino acids. These results suggest that inducible special racemase enzymes, which can convert D-amino acids back to their native L-forms, are widespread among soil microorganisms. This finding does not rule out the possibility that some plants may out-compete microorganisms and be able to access D-amino acids. It does suggest, however, that rhizosphere bacteria can shield plants from the toxic effect of D-amino acids.

  20. Differences in phytotoxicity and dissipation between ionized and nonionized oil sands naphthenic acids in wetland plants.

    PubMed

    Armstrong, Sarah A; Headley, John V; Peru, Kerry M; Germida, James J

    2009-10-01

    Naphthenic acids (NAs) are composed of alkyl-substituted acyclic and cycloaliphatic carboxylic acids and, because they are acutely toxic to fish, are of toxicological concern. During the caustic hot-water extraction of oil from the bitumen in oil sands deposits, NAs become concentrated in the resulting tailings pond water. The present study investigated if dissipation of NAs occurs in the presence of hydroponically grown emergent macrophytes (Typha latifolia, Phragmites australis, and Scirpus acutus) to determine the potential for phytoremediation of these compounds. Plants were grown with oil sands NAs (pKa approximately 5-6) in medium at pH 7.8 (predominantly ionized NAs) and pH 5.0 (predominantly nonionized NAs) to determine if, by altering their chemical form, NAs may be more accessible to plants and, thus, undergo increased dissipation. Whereas the oil sands NA mixture in its nonionized form was more toxic to wetland plants than its ionized form, neither form appeared to be sequestered by wetland plants. The present study demonstrated that plants may selectively enhance the dissipation of individual nonionized NA compounds, which contributes to toxicity reduction but does not translate into detectable total NA dissipation within experimental error and natural variation. Plants were able to reduce the toxicity of a NA system over 30 d, increasing the median lethal concentration (LC50; % of hydroponic solution) of the medium for Daphnia magna by 23.3% +/- 8.1% (mean +/- standard error; nonionized NAs) and 37.0% +/- 2.7% (ionized NAs) as determined by acute toxicity bioassays. This reduction in toxicity was 7.3% +/- 2.6% (nonionized NAs) and 45.0% +/- 6.8% (ionized NAs) greater than that in unplanted systems.

  1. Carnitine is associated with fatty acid metabolism in plants.

    PubMed

    Bourdin, Benoîte; Adenier, Hervé; Perrin, Yolande

    2007-12-01

    The finding of acylcarnitines alongside free carnitine in Arabidopsis thaliana and other plant species, using tandem mass spectrometry coupled to liquid chromatography shows a link between carnitine and plant fatty acid metabolism. Moreover the occurrence of both medium- and long-chain acylcarnitines suggests that carnitine is connected to diverse fatty acid metabolic pathways in plant tissues. The carnitine and acylcarnitine contents in plant tissues are respectively a hundred and a thousand times lower than in animal tissues, and acylcarnitines represent less than 2% of the total carnitine pool whereas this percentage reaches 30% in animal tissues. These results suggest that carnitine plays a lesser role in lipid metabolism in plants than it does in animals.

  2. Naphthenic acids degradation and toxicity mitigation in tailings wastewater systems and aquatic environments: a review.

    PubMed

    Kannel, Prakash R; Gan, Thian Y

    2012-01-01

    Naphthenic acids, NAs (classical formula C(n)H(2n+z)O(2), where n is the carbon numbers, z represents zero or negative even integers), found in oil sands process waters (OSPWs), are toxic to aquatic environments depending upon several factors such as pH, salinity, molecular size and chemical structure of NAs. Among various available methods, biodegradation seems to be generally the most cost-effective method for decreasing concentrations of NAs (n ≤ 21) and reducing their associated toxicity in OSPW, however the mechanism by which the biodegradation of NAs occurs are poorly understood. Ozonation is superior over biodegradation in decreasing higher molecular weight alkyl branched NAs (preferentially, n ≥ 22, -6 ≥ z ≥ -12) as well as enabling accelerated biodegradation and reducing toxicity. Photolysis (UV at 254 nm) is effective in cleaving higher molecular weight NAs into smaller fragments that will be easier for microorganisms to degrade, whereas photocatalysis can metabolize selective NAs (0 ≥ z ≥ -6) efficiently and minimize their associated toxicity. Phytoremediation is applicable for metabolizing specific NAs (O(2), O(3), O(4), and O(5) species) and minimizing their associated toxicities. Petroleum coke (PC) adsorption is effective in reducing the more structurally complex NAs (preferentially 12 ≥ n ≥ 18 and z = -10, -12) and their toxicity in OSPWs, depending upon the PC content, pH and temperature. Several factors have influence on the degradation of NAs in OSPWs and aquatic environments, which include molecular mass and chemical structure of NAs, sediment structure, temperature, pH, dissolved oxygen, nutrients, and bacteria types.

  3. ACID/HEAVY METAL TOLERANT PLANTS

    EPA Science Inventory

    This report summarizes the results of Mine Waste Technology Program (MWTP) Activity III, Project 30. The objective of Project 30 was to select populations (i.e., ecotypes) from native, indigenous plant species that demonstrate superior growth characteristics and sustainability on...

  4. Plant amino acid-derived vitamins: biosynthesis and function.

    PubMed

    Miret, Javier A; Munné-Bosch, Sergi

    2014-04-01

    Vitamins are essential organic compounds for humans, having lost the ability to de novo synthesize them. Hence, they represent dietary requirements, which are covered by plants as the main dietary source of most vitamins (through food or livestock's feed). Most vitamins synthesized by plants present amino acids as precursors (B1, B2, B3, B5, B7, B9 and E) and are therefore linked to plant nitrogen metabolism. Amino acids play different roles in their biosynthesis and metabolism, either incorporated into the backbone of the vitamin or as amino, sulfur or one-carbon group donors. There is a high natural variation in vitamin contents in crops and its exploitation through breeding, metabolic engineering and agronomic practices can enhance their nutritional quality. While the underlying biochemical roles of vitamins as cosubstrates or cofactors are usually common for most eukaryotes, the impact of vitamins B and E in metabolism and physiology can be quite different on plants and animals. Here, we first aim at giving an overview of the biosynthesis of amino acid-derived vitamins in plants, with a particular focus on how this knowledge can be exploited to increase vitamin contents in crops. Second, we will focus on the functions of these vitamins in both plants and animals (and humans in particular), to unravel common and specific roles for vitamins in evolutionary distant organisms, in which these amino acid-derived vitamins play, however, an essential role.

  5. The effect of natrojarosite addition to mine tailings.

    PubMed

    Jurjovec, Jasna; Ptacek, Carol J; Blowes, David W; Jambor, John L

    2003-01-01

    An increasingly common practice for metallurgical plants is to discard their wastes by combining them with mine tailings prior to disposing the blended material to a containment facility. This practice has occurred since 1985 at the Kidd Creek tailings impoundment where natrojarosite, a waste produced from the adjacent Zn refinery, is combined with mine tailings and is deposited in a single impoundment. To assess the environmental impact of the co-disposal, a laboratory column experiment was conducted. The column material was flotation tailings from the Kidd Creek site containing 3 wt % natrojarosite residue. Dilute sulfuric acid was passed through the column to simulate the acid generated in the unsaturated zone of the tailings impoundment. The results of this experiment were compared to the results of a previous experiment conducted on unamended flotation tailings. The results showed that the effluent from the column containing the natrojarosite-bearing mixture had a faster decrease in pH, earlier increases in the concentrations of dissolved metals such as Pb and Cd, and a greater persistence in effluent metal concentrations such as Pb, Zn and Ni. To prevent the observed enhanced release of dissolved metals from mine waste disposal areas, natrojarosite should not be co-disposed with tailings.

  6. The potential use of Piptatherum miliaceum for the phytomanagement of mine tailings in semiarid areas: Role of soil fertility and plant competition.

    PubMed

    Parraga-Aguado, Isabel; González-Alcaraz, María Nazaret; Schulin, Rainer; Conesa, Héctor M

    2015-08-01

    Phytomanagement in terms of phytostabilisation has been proposed as a suitable technique to decrease the environmental risks of metal(loid) enriched mine tailings. Nevertheless, at these sites some issues must be solved to assure the long-term establishment of vegetation (e.g. salinity, low fertility, metal(loid) phytotoxicity, etc.) The objective of this study was to assess the effects of the addition of a municipal solid waste on a mine tailings soil and on the growth and metal(loid) accumulation of a grass plant species (Piptatherum miliaceum). In addition, the effects of intra-specific interactions were evaluated. A pot experiment was performed during 8 months, including two soil treatments: the mine soil and its combination with municipal solid wastes. For each treatment, pots without plants, pots with one plant, and pots with two plants were arranged. The addition of municipal solid wastes improved the soil fertility and plant growth in the mine soil, but also increased the mobile fractions of Zn, Pb, Cd, Mn and Ni. Plants in the amended treatments showed better nutritional status (higher P and K). Stable isotope δ(15)N was associated to the better nutritional status, while δ(13)C and δ(18)O indicated higher photosynthetic efficiency and stomatal conductance in amended treatments. Although the accumulation in leaves of most metal(loid)s decreased with the municipal waste application, the concentrations in both treatments did not exceed toxic limits for fodder. There was an effect of intra-specific competition in plant growth, probably due to lack of nutrients in the mining soil or limited pots volume in the treatments with municipal waste.

  7. Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants

    DOEpatents

    Somerville, C.; Loo, F. van de

    1997-09-16

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds. 35 figs.

  8. Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    1998-01-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  9. Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    2002-01-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  10. Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants

    DOEpatents

    Somerville, C.; Loo, F. van de

    1998-09-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds. 35 figs.

  11. Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    1997-01-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  12. Microbial products trigger amino acid exudation from plant roots.

    PubMed

    Phillips, Donald A; Fox, Tama C; King, Maria D; Bhuvaneswari, T V; Teuber, Larry R

    2004-09-01

    Plants naturally cycle amino acids across root cell plasma membranes, and any net efflux is termed exudation. The dominant ecological view is that microorganisms and roots passively compete for amino acids in the soil solution, yet the innate capacity of roots to recover amino acids present in ecologically relevant concentrations is unknown. We find that, in the absence of culturable microorganisms, the influx rates of 16 amino acids (each supplied at 2.5 microm) exceed efflux rates by 5% to 545% in roots of alfalfa (Medicago sativa), Medicago truncatula, maize (Zea mays), and wheat (Triticum aestivum). Several microbial products, which are produced by common soil microorganisms such as Pseudomonas bacteria and Fusarium fungi, significantly enhanced the net efflux (i.e. exudation) of amino acids from roots of these four plant species. In alfalfa, treating roots with 200 microm phenazine, 2,4-diacetylphloroglucinol, or zearalenone increased total net efflux of 16 amino acids 200% to 2,600% in 3 h. Data from (15)N tests suggest that 2,4-diacetylphloroglucinol blocks amino acid uptake, whereas zearalenone enhances efflux. Thus, amino acid exudation under normal conditions is a phenomenon that probably reflects both active manipulation and passive uptake by microorganisms, as well as diffusion and adsorption to soil, all of which help overcome the innate capacity of plant roots to reabsorb amino acids. The importance of identifying potential enhancers of root exudation lies in understanding that such compounds may represent regulatory linkages between the larger soil food web and the internal carbon metabolism of the plant.

  13. A greenhouse trial to investigate the ameliorative properties of biosolids and plants on physicochemical conditions of iron ore tailings: Implications for an iron ore mine site remediation.

    PubMed

    Cele, Emmanuel Nkosinathi; Maboeta, Mark

    2016-01-01

    An iron ore mine site in Swaziland is currently (2015) in a derelict state as a consequence of past (1964-1988) and present (2011 - current) iron ore mining operations. In order to control problems associated with mine wastes, the Swaziland Water Services Corporation (SWSC) recently (2013) proposed the application of biosolids in sites degraded by mining operations. It is thought that this practice could generally improve soil conditions and enhance plant reestablishment. More importantly, the SWSC foresees this as a potential solution to the biosolids disposal problems. In order to investigate the effects of biosolids and plants in soil physicochemical conditions of iron mine soils, we conducted two plant growth trials. Trial 1 consisted of tailings that received biosolids and topsoil (TUSB mix) while in trial 2, tailings received biosolids only (TB mix). In the two trials, the application rates of 0 (control), 10, 25, 50, 75 and 100 t ha(-1) were used. After 30 days of equilibration, 25 seeds of Cynodon dactylon were sown in each pot and thinned to 10 plants after 4 weeks. Plants were watered twice weekly and remained under greenhouse conditions for 12 weeks, subsequent to which soils were subjected to chemical analysis. According to the results obtained, there were significant improvements in soil parameters related to fertility such as organic matter (OM), water holding capacity (WHC), cation exchange capacity (CEC), ammonium [Formula: see text] , magnesium (Mg(2+)), calcium (Ca(2+)) and phosphorus ( [Formula: see text] ). With regard to heavy metals, biosolids led to significant increases in soil total concentrations of Cu, Zn, Cd, Hg and Pb. The higher concentrations of Zn and Cu in treated tailings compared to undisturbed adjacent soils are a cause for concern because in the field, this might work against the broader objectives of mine soil remediation, which include the recolonization of reclaimed sites by soil-dwelling organisms. Therefore, while

  14. Collaborative effort to model plant response to acidic rain

    SciTech Connect

    Jacobson, J.; Kuja, A.; Shriner, D.; Perrigan, S.; Irving, P.; Lee, J.; Troiano, J.; Cullinan, V.

    1988-06-01

    Radish plants were exposed three times per week to simulated acidic rain at pH values of 2.6 to 5.4 over the course of four weeks in trials performed at Argonne, Illinois; Ithaca and Upton, New York; Corvallis, Oregon; Oak Ridge, Tennessee; and Toronto, Canada. Uniform genotype, soil media and planting techniques, treatment procedures, biological measurements, and experimental design were employed. Growth of plants differed among trials as a result of variation in greenhouse environmental conditions according to location and facilities. Larger plants underwent greater absolute but lower relative reductions in biomass after exposure to the higher levels of acidity. A generalized Mitscherlich function was used to model the effects of acidity of simulated rain or dry mass of hypocotyls using data from three laboratories that performed duplicate trials. The remaining data, from three other laboratories that performed only one trial each, were used to test the model. When the laboratory by trial effect was removed, lack of fit to the Mitscherlich function was insignificant. Thus, a single mathematical model satisfactorily characterized the relationship between acidity and mean plant response.

  15. Abscisic acid controlled sex before transpiration in vascular plants.

    PubMed

    McAdam, Scott A M; Brodribb, Timothy J; Banks, Jo Ann; Hedrich, Rainer; Atallah, Nadia M; Cai, Chao; Geringer, Michael A; Lind, Christof; Nichols, David S; Stachowski, Kye; Geiger, Dietmar; Sussmilch, Frances C

    2016-10-26

    Sexual reproduction in animals and plants shares common elements, including sperm and egg production, but unlike animals, little is known about the regulatory pathways that determine the sex of plants. Here we use mutants and gene silencing in a fern species to identify a core regulatory mechanism in plant sexual differentiation. A key player in fern sex differentiation is the phytohormone abscisic acid (ABA), which regulates the sex ratio of male to hermaphrodite tissues during the reproductive cycle. Our analysis shows that in the fern Ceratopteris richardii, a gene homologous to core ABA transduction genes in flowering plants [SNF1-related kinase2s (SnRK2s)] is primarily responsible for the hormonal control of sex determination. Furthermore, we provide evidence that this ABA-SnRK2 signaling pathway has transitioned from determining the sex of ferns to controlling seed dormancy in the earliest seed plants before being co-opted to control transpiration and CO2 exchange in derived seed plants. By tracing the evolutionary history of this ABA signaling pathway from plant reproduction through to its role in the global regulation of plant-atmosphere gas exchange during the last 450 million years, we highlight the extraordinary effect of the ABA-SnRK2 signaling pathway in plant evolution and vegetation function.

  16. Listeria phage and phage tail induction triggered by components of bacterial growth media (phosphate, LiCl, nalidixic acid, and acriflavine).

    PubMed

    Lemaître, Jean-Paul; Duroux, Amandine; Pimpie, Romain; Duez, Jean-Marie; Milat, Marie-Louise

    2015-03-01

    The detection of Listeria monocytogenes from food is currently carried out using a double enrichment. For the ISO methodology, this double enrichment is performed using half-Fraser and Fraser broths, in which the overgrowth of L. innocua can occur in samples where both species are present. In this study, we analyzed the induction of phages and phage tails of Listeria spp. in these media and in two brain heart infusion (BHI) broths (BHIM [bioMérieux] and BHIK [Biokar]) to identify putative effectors. It appears that Na2HPO4 at concentrations ranging from 1 to 40 g/liter with an initial pH of 7.5 can induce phage or phage tail production of Listeria spp., especially with 10 g/liter of Na2HPO4 and a pH of 7.5, conditions present in half-Fraser and Fraser broths. Exposure to LiCl in BHIM (18 to 21 g/liter) can also induce phage and phage tail release, but in half-Fraser and Fraser broths, the concentration of LiCl is much lower (3 g/liter). Low phage titers were induced by acriflavine and/or nalidixic acid. We also show that the production of phages and phage tails can occur in half-Fraser and Fraser broths. This study points out that induction of phages and phage tails could be triggered by compounds present in enrichment media. This could lead to a false-negative result for the detection of L. monocytogenes in food products.

  17. Gamma amino butyric acid accumulation in medicinal plants without stress

    PubMed Central

    Anju, P.; Moothedath, Ismail; Rema Shree, Azhimala Bhaskaranpillai

    2014-01-01

    Introduction: Gamma amino butyric acid (GABA) is an important ubiquitous four carbon nonprotein amino acid with an amino group attached to gamma carbon instead of beta carbon. It exists in different organisms including bacteria, plants, and animals and plays a crucial role in humans by regulating neuronal excitability throughout the nervous system. It is directly responsible for the regulation of muscle tone and also effective in lowering stress, blood pressure, and hypertension. Aim and Objective: The aim of the study was to develop the fingerprint profile of selected medicinally and economically important plants having central nervous system (CNS) activity and to determine the quantity of GABA in the selected plants grown under natural conditions without any added stress. Materials and Methods: The high-performance thin layer chromatography analysis was performed on precoated silica gel plate 60F–254 plate (20 cm × 10 cm) in the form of bands with width 8 mm using Hamilton syringe (100 μl) using n-butanol, acetic acid, and water in the proportion 5:2:2 as mobile phase in a CAMAG chamber which was previously saturated for 30 min. CAMAG TLC scanner 3 was used for the densitometric scanning at 550 nm. Specific marker compounds were used for the quantification. Results and Conclusion: Among the screened medicinal plants, Zingiber officinale and Solanum torvum were found to have GABA. The percentage of GABA present in Z. officinale and S. torvum were found to be 0.0114% and 0.0119%, respectively. The present work confirmed that among the selected CNS active medicinal plants, only two plants contain GABA. We found a negative correlation with plant having CNS activity and accumulation of GABA. The GABA shunt is a conserved pathway in eukaryotes and prokaryotes but, although the role of GABA as a neurotransmitter in mammals is clearly established, its role in plants is still vague. PMID:25861139

  18. Perfluoroalkyl acid distribution in various plant compartments ...

    EPA Pesticide Factsheets

    Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var.dulce), tomato (Lycopersicon lycopersicum), and sugar snap pea (Pisum sativum var. macrocarpon) from an industrially impacted biosolids-amended soil, a municipal biosolids­ amended soil, and a control soil. Individual concentrations of PFAAs, on a dry weight basis, in mature, edible portions of crops grown in soil amended with PFAA industrially impacted biosolids were highest for perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate (PFBA;232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit. Comparatively, PFAA concentrations in edible compartments of crops grown in the municipal biosolids-amended soil and in the control soil were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated for the root, shoot, and fruit compartments (as applicable) of all crops grown in the industrially impacted soil. BAFs were highest for PFBA in the shoots of all crops, as well as in the fruit compartment of pea. Root­ soil concentration factors (RCFs) for tomato and pea were independent of PFAA chain length, while radish and celery RCFs showed a slight decrease with increasing chain length. Shoot-soil concentration factors (SCFs) for all crops showed a decrease with incre

  19. Screening of plant species for phytoremediation of uranium, thorium, barium, nickel, strontium and lead contaminated soils from a uranium mill tailings repository in South China.

    PubMed

    Li, Guang-yue; Hu, Nan; Ding, De-xin; Zheng, Ji-fang; Liu, Yu-long; Wang, Yong-dong; Nie, Xiao-qin

    2011-06-01

    The concentrations of uranium, thorium, barium, nickel, strontium and lead in the samples of the tailings and plant species collected from a uranium mill tailings repository in South China were analyzed. Then, the removal capability of a plant for a target element was assessed. It was found that Phragmites australis had the greatest removal capabilities for uranium (820 μg), thorium (103 μg) and lead (1,870 μg). Miscanthus floridulus had the greatest removal capabilities for barium (3,730 μg) and nickel (667 μg), and Parthenocissus quinquefolia had the greatest removal capability for strontium (3,920 μg). In this study, a novel coefficient, termed as phytoremediation factor (PF), was proposed, for the first time, to assess the potential of a plant to be used in phytoremediation of a target element contaminated soil. Phragmites australis has the highest PFs for uranium (16.6), thorium (8.68), barium (10.0) and lead (10.5). Miscanthus floridulus has the highest PF for Ni (25.0). Broussonetia papyrifera and Parthenocissus quinquefolia have the relatively high PFs for strontium (28.1 and 25.4, respectively). On the basis of the definition for a hyperaccumulator, only Cyperus iria and Parthenocissus quinquefolia satisfied the criteria for hyperaccumulator of uranium (36.4 μg/g) and strontium (190 μg/g), and could be the candidates for phytoremediation of uranium and strontium contaminated soils. The results show that the PF has advantage over the hyperaccumulator in reflecting the removal capabilities of a plant for a target element, and is more adequate for assessing the potential of a plant to be used in phytoremediation than conventional method.

  20. Tail Buffeting

    NASA Technical Reports Server (NTRS)

    Abdrashitov, G.

    1943-01-01

    An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting.

  1. Immunomodulatory lipids in plants: plant fatty acid amides and the human endocannabinoid system.

    PubMed

    Gertsch, Jürg

    2008-05-01

    Since the discovery that endogenous lipid mediators show similar cannabimimetic effects as phytocannabinoids from CANNABIS SATIVA, our knowledge about the endocannabinoid system has rapidly expanded. Today, endocannabinoid action is known to be involved in various diseases, including inflammation and pain. As a consequence, the G-protein coupled cannabinoid receptors, endocannabinoid transport, as well as endocannabinoid metabolizing enzymes represent targets to block or enhance cannabinoid receptor-mediated signalling for therapeutic intervention. Based on the finding that certain endocannabinoid-like fatty acid N-alkylamides from purple coneflower ( ECHINACEA spp.) potently activate CB2 cannabinoid receptors we have focused our interest on plant fatty acid amides (FAAs) and their overall cannabinomodulatory effects. Certain FAAs are also able to partially inhibit the action of fatty acid amide hydrolase (FAAH), which controls the breakdown of endocannabinoids. Intriguingly, plants lack CB receptors and do not synthesize endocannabinoids, but express FAAH homologues capable of metabolizing plant endogenous N-acylethanolamines (NAEs). While the site of action of these NAEs in plants is unknown, endogenous NAEs and arachidonic acid glycerols in animals interact with distinct physiological lipid receptors, including cannabinoid receptors. There is increasing evidence that also plant FAAs other than NAEs can pharmacologically modulate the action of these endogenous lipid signals. The interference of plant FAAs with the animal endocannabinoid system could thus be a fortunate evolutionary cross point with yet unexplored therapeutic potential.

  2. Educational outreach and impacts of white-tailed deer browse on native and invasive plants at the Crooked Creek Environmental Learning Center, Armstrong County, Pennsylvania

    NASA Astrophysics Data System (ADS)

    Lindsay, Lisa O.

    Overabundance of deer can assist the intrusion of invasive plants through browse, leading to homogenization of plant communities. Public attitudes towards native and invasive plant species and white-tailed deer browse related to personal experiences, can be changed through education focusing public awareness of ramifications of deer browse on native and invasive plants. I developed an interactive, interpretive Self-Guided Walking Tour brochure of the "You Can Trail" to provide an educational outreach program for visitors of Crooked Creek Environmental Learning Center that includes ecologically important native and invasive plants species from my investigation. This research study focuses on the overall abundance of native and invasive plant species once Odocoileus virginianus have been removed from the landscape during collection periods in June and September 2013 from exclosure and access plots that were maintained for seven years. Similarity of abundance were found in native and invasive abundance of forbs, bushes and percentage of ground cover. Differences included native bush volume being greater than invasive bush volume in the access plot in June with opposing results in the exclosure plot, being greater in invasive bush volume. However, in September, native and invasive bush volume was similar within the exclosure plot, while invasive bush volume decreased in the access plot. Invasive vines recorded in the June access plot were absent in the September collection period.

  3. Uptake of gaseous nitrous acid (HONO) by several plant species

    NASA Astrophysics Data System (ADS)

    Schimang, Ralf; Folkers, Achim; Kleffmann, Jörg; Kleist, Einhard; Miebach, Marco; Wildt, Jürgen

    Uptake of gaseous nitrous acid (HONO) by sunflower ( Heliantus annuus L. var. gigantheus), tobacco ( Nicotiana tabacum L. var. Bel W3), castor ( Rhicinus communis L. var. Carmencita), and birch ( Betula pendula L.) was studied under controlled conditions in a continuously stirred tank reactor. Exposing plants to HONO at concentrations between 60 ppt and 10 ppb led to significant uptake by the plants. The uptake was proportional to HONO concentrations and linearly related to stomatal conductivity. HONO losses at the cuticle were of minor importance. Our data imply a quick metabolism of HONO and it is concluded that the uptake of HONO by plants is only limited by diffusion of HONO through the plants stomata. Comparing results from measurements with and without plants in the chamber it is furthermore concluded that a compensation point for HONO uptake is below 20 ppt if it exists at all. Heterogeneous formation of HONO by reactions of NO 2 on the plant surfaces was either not effective or compensated by the stomatal uptake of HONO. The data of the present study imply that plant surfaces represent a sink for HONO. Therefore, it was concluded that processes on plant surfaces cannot explain HONO formation on ground surfaces as observed in field studies.

  4. Glutamate receptor-like channels in plants: a role as amino acid sensors in plant defence?

    PubMed Central

    Roberts, Michael R.

    2014-01-01

    Plant glutamate receptor-like genes (GLRs) are homologous to the genes for mammalian ionotropic glutamate receptors (iGluRs), after which they were named, but in the 16 years since their existence was first revealed, progress in elucidating their biological role has been disappointingly slow. Recently, however, studies from a number of laboratories focusing on the model plant species Arabidopsis thaliana (L.) have thrown new light on the functional properties of some members of the GLR gene family. One important finding has been that plant GLR receptors have a much broader ligand specificity than their mammalian iGluR counterparts, with evidence that some individual GLR receptors can be gated by as many as seven amino acids. These results, together with the ubiquity of their expression throughout the plant, open up the possibility that GLR receptors could have a pervasive role in plants as non-specific amino acid sensors in diverse biological processes. Addressing what one of these roles could be, recent studies examining the wound response and disease susceptibility in GLR knockout mutants have provided evidence that some members of clade 3 of the GLR gene family encode important components of the plant's defence response. Ways in which this family of amino acid receptors might contribute to the plant's ability to respond to an attack from pests and pathogens are discussed. PMID:24991414

  5. Isolation of lactic acid-forming bacteria from biogas plants.

    PubMed

    Bohn, Jelena; Yüksel-Dadak, Aytül; Dröge, Stefan; König, Helmut

    2017-02-20

    Direct molecular approaches provide hints that lactic acid bacteria play an important role in the degradation process of organic material to methanogenetic substrates in biogas plants. However, their diversity in biogas fermenter samples has not been analyzed in detail yet. For that reason, five different biogas fermenters, which were fed mainly with maize silage and manure from cattle or pigs, were examined for the occurrence of lactic acid-forming bacteria. A total of 197 lactic acid-forming bacterial strains were isolated, which we assigned to 21 species, belonging to the genera Bacillus, Clostridium, Lactobacillus, Pediococcus, Streptococcus and Pseudoramibacter-related. A qualitative multiplex system and a real-time quantitative PCR could be developed for most isolates, realized by the selection of specific primers. Their role in biogas plants was discussed on the basis of the quantitative results and on physiological data of the isolates.

  6. 76 FR 63878 - New Source Performance Standards Review for Nitric Acid Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ... AGENCY 40 CFR Part 60 RIN 2060-AQ10 New Source Performance Standards Review for Nitric Acid Plants AGENCY... source performance standards (NSPS) for nitric acid plants. Nitric acid plants include one or more nitric acid production units. These proposed revisions include a change to the nitrogen oxides (NO...

  7. Innovative Approach to Prevent Acid Drainage from Uranium Mill Tailings Based on the Application of Na-Ferrate (VI)

    SciTech Connect

    Fernandes, H.M.; Reinhart, D.; Lettie, L.; Franklin, M.R.; Fernandes, H.M.; Franklin, M.R.; Daly, L.J.

    2006-07-01

    The operation of uranium mining and milling plants gives rise to huge amounts of wastes from both mining and milling operations. When pyrite is present in these materials, the generation of acid drainage can take place and result in the contamination of underground and surface waters through the leaching of heavy metals and radionuclides. To solve this problem, many studies have been conducted to find cost-effective solutions to manage acid mine drainage; however, no adequate strategy to deal with sulfide-ric h wastes is currently available. Ferrate (VI) is a powerful oxidizing agent in aqueous media. Under acidic conditions, the redox potential of the Ferrate (VI) ion is the highest of any other oxidant used in wastewater treatment processes. The standard half cell reduction potential of ferrate (VI) has been determined as +2.20 V to + 0.72 V in acidic and basic solutions, respectively. Ferrate (VI) exhibits a multitude of advantageous properties, including higher reactivity and selectivity than traditional oxidant alternatives, as well as disinfectant, flocculating, and coagulant properties. Despite numerous beneficial properties in environmental applications, ferrate (VI) has remained commercially unavailable. Starting in 1953, different methods for producing a high purity, powdered ferrate (VI) product were developed. However, producing this dry, stabilized ferrate (VI) product required numerous process steps which led to excessive synthesis costs (over $20/lb) thereby preventing bulk industrial use. Recently a novel synthesis method for the production of a liquid ferrate (VI) based on hypochlorite oxidation of ferric ion in strongly alkaline solutions has been discovered (USPTO 6,790,428; September 14, 2004). This on-site synthesis process dramatically reduces manufacturing cost for the production of ferrate (VI) by utilizing common commodity feedstocks. This breakthrough means that for the first time ferrate (VI) can be an economical alternative to treating

  8. Effects of organic acids on the photosynthetic and antioxidant properties and accumulations of heavy metals of Melilotus officinalis grown in Cu tailing.

    PubMed

    Han, Yulin; Wu, Xue; Gu, Jiguang; Zhao, Jiuzhou; Huang, Suzhen; Yuan, Haiyan; Fu, Jiajia

    2016-09-01

    The effect of citric acid (CA), acetic acid (Ac), and ethylene diamine tetraacetic acid (EDTA) on the photosynthetic and antioxidant properties and the accumulation of some heavy metals (HMs) of Melilotus officinalis seedling growing in Cu mine tailings for 25 days were studied. Results showed that the formation of photosynthesizing cells of M. officinalis was inhibited by EDTA at 2 mmol/kg. Photosynthetic pigment contents under EDTA of 2 mmol/kg were reduced by 26, 40, and 19 %, respectively, compared to the control. The proline contents in aboveground and underground parts increased as the level of EDTA was enhanced. CA and Ac enhanced the activities of superoxide dismutase (SOD) and peroxidase (POD) in the aboveground parts and EDTA inhibited the activity of POD in the underground parts. The addition of CA promoted significantly the growth of M. officinalis, while the biomass decreased significantly under 2 mmol/kg EDTA. Cu contents in the aboveground parts treated with 0.5 and 2.0 mmol/kg EDTA reached 175.50 and 265.17 μg/g dry weight, respectively. Ac and EDTA treatments promoted Cd to translocate from root to aboveground parts. The result indicated that M. officinalis was a tolerant species of Cu tailing and can be used to remediate Cu contaminated environment, and rationally utilization of organic acids, especially EDTA, in the phytoremediation can improve the growth and metals accumulation of M. officinalis.

  9. Benefits to rare plants and highway safety from annual population reductions of a "native invader," white-tailed deer, in a Chicago-area woodland.

    PubMed

    Engeman, Richard M; Guerrant, Travis; Dunn, Glen; Beckerman, Scott F; Anchor, Chris

    2014-01-01

    Overabundant white-tailed deer are one of the most serious threats to woodland plant communities in the Chicago area. Moreover, the abundant deer in a highly populated area causes economic harm and poses hazards to human safety through collisions with vehicles. The artificial conditions causing the overabundance and resulting consequences qualify the white-tailed deer in the Chicago area to be considered as "native invaders". We examined the benefits of culling deer at a Chicago-area woodland preserve by comparing browse rates on four endangered plant species from years before culling began with years with culling. We also examined deer-vehicle collision and traffic flow rates on area roads from years before culling began and years with culling to assess whether population reductions may have benefited road safety in the area. All four endangered plant species (three orchid species and sweet fern) had lower browse rates in years with culls, although the decreased browsing rates were statistically distinguishable for only two of the species (grass pink orchid and sweet fern). After first verifying that traffic flow rates did not decrease from pre-cull years to years with culls, we analyzed the Illinois Department of Transportation data from area roads based on deer-vehicle collisions causing >US$500 in damage and showed a one-third reduction in deer-vehicle collisions. An economic analysis showed a cost savings during the cull years of US$0.6 million for reducing browsing to just these four monitored plant species and the reduction in deer-vehicle collisions.

  10. Long-Term Effects of White-Tailed Deer Exclusion on the Invasion of Exotic Plants: A Case Study in a Mid-Atlantic Temperate Forest

    PubMed Central

    Shen, Xiaoli; Bourg, Norman A.; McShea, William J.; Turner, Benjamin L.

    2016-01-01

    Exotic plant invasions and chronic high levels of herbivory are two of the major biotic stressors impacting temperate forest ecosystems in eastern North America, and the two problems are often linked. We used a 4-ha deer exclosure maintained since 1991 to examine the influence of a generalist herbivore, white-tailed deer (Odocoileus virginianus), on the abundance of four exotic invasive (Rosa multiflora, Berberis thunbergii, Rubus phoenicolasius and Microstegium vimineum) and one native (Cynoglossum virginianum) plant species, within a 25.6-ha mature temperate forest dynamics plot in Virginia, USA. We identified significant predictors of the abundance of each focal species using generalized linear models incorporating 10 environmental and landscape variables. After controlling for those predictors, we applied our models to a 4-ha deer exclusion site and a 4-ha reference site, both embedded within the larger plot, to test the role of deer on the abundance of the focal species. Slope, edge effects and soil pH were the most frequent predictors of the abundance of the focal species on the larger plot. The abundance of C. virginianum, known to be deer-dispersed, was significantly lower in the exclosure. Similar patterns were detected for B. thunbergii, R. phoenicolasius and M. vimineum, whereas R. multiflora was more abundant within the exclosure. Our results indicate that chronic high deer density facilitates increased abundances of several exotic invasive plant species, with the notable exception of R. multiflora. We infer that the invasion of many exotic plant species that are browse-tolerant to white-tailed deer could be limited by reducing deer populations. PMID:27019356

  11. Long-Term Effects of White-Tailed Deer Exclusion on the Invasion of Exotic Plants: A Case Study in a Mid-Atlantic Temperate Forest.

    PubMed

    Shen, Xiaoli; Bourg, Norman A; McShea, William J; Turner, Benjamin L

    2016-01-01

    Exotic plant invasions and chronic high levels of herbivory are two of the major biotic stressors impacting temperate forest ecosystems in eastern North America, and the two problems are often linked. We used a 4-ha deer exclosure maintained since 1991 to examine the influence of a generalist herbivore, white-tailed deer (Odocoileus virginianus), on the abundance of four exotic invasive (Rosa multiflora, Berberis thunbergii, Rubus phoenicolasius and Microstegium vimineum) and one native (Cynoglossum virginianum) plant species, within a 25.6-ha mature temperate forest dynamics plot in Virginia, USA. We identified significant predictors of the abundance of each focal species using generalized linear models incorporating 10 environmental and landscape variables. After controlling for those predictors, we applied our models to a 4-ha deer exclusion site and a 4-ha reference site, both embedded within the larger plot, to test the role of deer on the abundance of the focal species. Slope, edge effects and soil pH were the most frequent predictors of the abundance of the focal species on the larger plot. The abundance of C. virginianum, known to be deer-dispersed, was significantly lower in the exclosure. Similar patterns were detected for B. thunbergii, R. phoenicolasius and M. vimineum, whereas R. multiflora was more abundant within the exclosure. Our results indicate that chronic high deer density facilitates increased abundances of several exotic invasive plant species, with the notable exception of R. multiflora. We infer that the invasion of many exotic plant species that are browse-tolerant to white-tailed deer could be limited by reducing deer populations.

  12. Preparation and characterization of TiO2/acid leached serpentinite tailings composites and their photocatalytic reduction of chromium(VI).

    PubMed

    Sun, Zhiming; Zheng, Liming; Zheng, Shuilin; Frost, Ray L

    2013-08-15

    Composite TiO2/acid leached serpentine tailings (AST) were synthesized through the hydrolysis-deposition method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and surface area measurement (BET). The XRD analysis showed that TiO2 coated on the surface of acid leached serpentine tailings was mixed crystal phases of rutile and anatase, the grain size of which is 10-30 nm. SEM, TEM, and EDS analysis exhibited that nano-TiO2 particles were deposited on the surface and internal cavities of acid leaching serpentine tailings. The XPS and FT-IR analysis demonstrated that the coating process of TiO2 on AST was a physical adsorption process. The large specific surface area, porous structure, and plentiful surface hydroxyl group of TiO2/AST composite resulted in the high adsorption capacity of Cr(VI). The experimental results demonstrated that initial concentration of Cr(VI), the amount of the catalyst, and pH greatly influenced the removal efficiency of Cr(VI). The removal kinetics of Cr(VI) at a relative low initial concentration was fitted well with Langmuir-Hinshelwood kinetics model with R(2) value of about unity. The as-prepared composites exhibited strong adsorption and photocatalytic capacity for the removal of Cr(VI), and the possible photocatalytic reduction mechanism was studied. The photodecomposition of Cr(VI) was as high as 95% within 2h, and the reusability of the photocatalysis was proven.

  13. Regulation of amino acid metabolic enzymes and transporters in plants.

    PubMed

    Pratelli, Réjane; Pilot, Guillaume

    2014-10-01

    Amino acids play several critical roles in plants, from providing the building blocks of proteins to being essential metabolites interacting with many branches of metabolism. They are also important molecules that shuttle organic nitrogen through the plant. Because of this central role in nitrogen metabolism, amino acid biosynthesis, degradation, and transport are tightly regulated to meet demand in response to nitrogen and carbon availability. While much is known about the feedback regulation of the branched biosynthesis pathways by the amino acids themselves, the regulation mechanisms at the transcriptional, post-transcriptional, and protein levels remain to be identified. This review focuses mainly on the current state of our understanding of the regulation of the enzymes and transporters at the transcript level. Current results describing the effect of transcription factors and protein modifications lead to a fragmental picture that hints at multiple, complex levels of regulation that control and coordinate transport and enzyme activities. It also appears that amino acid metabolism, amino acid transport, and stress signal integration can influence each other in a so-far unpredictable fashion.

  14. Metabolic regulation of the plant hormone indole-3-acetic acid

    SciTech Connect

    Jerry D. Cohen

    2009-11-01

    The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

  15. Amino acid-sensing ion channels in plants

    SciTech Connect

    Spalding, Edgar P.

    2014-08-12

    The title of our project is “Amino acid-sensing ion channels in plants”. Its goals are two-fold: to determine the molecular functions of glutamate receptor-like (GLR) proteins, and to elucidate their biological roles (physiological or developmental) in plants. Here is our final technical report. We were highly successful in two of the three aims, modestly successful in the third.

  16. Maintenance Carbon Cycle in Crassulacean Acid Metabolism Plant Leaves 1

    PubMed Central

    Kenyon, William H.; Severson, Ray F.; Black, Clanton C.

    1985-01-01

    The reciprocal relationship between diurnal changes in organic acid and storage carbohydrate was examined in the leaves of three Crassulacean acid metabolism plants. It was found that depletion of leaf hexoses at night was sufficient to account quantitatively for increase in malate in Ananas comosus but not in Sedum telephium or Kalanchoë daigremontiana. Fructose and to a lesser extent glucose underwent the largest changes. Glucose levels in S. telephium leaves oscillated diurnally but were not reciprocally related to malate fluctuations. Analysis of isolated protoplasts and vacuoles from leaves of A. comosus and S. telephium revealed that vacuoles contain a large percentage (>50%) of the protoplast glucose, fructose and malate, citrate, isocitrate, ascorbate and succinate. Sucrose, a major constituent of intact leaves, was not detectable or was at extremely low levels in protoplasts and vacuoles from both plants. In isolated vacuoles from both A. comosus and S. telephium, hexose levels decreased at night at the same time malate increased. Only in A. comosus, however, could hexose metabolism account for a significant amount of the nocturnal increase in malate. We conclude that, in A. comosus, soluble sugars are part of the daily maintenance carbon cycle and that the vacuole plays a dynamic role in the diurnal carbon assimilation cycle of this Crassulacean acid metabolism plant. PMID:16664005

  17. Abscisic Acid: a versatile phytohormone in plant signaling and beyond.

    PubMed

    Gomez-Cadenas, Aurelio; Vives, Vicente; Zandalinas, Sara I; Manzi, Matias; Sanchez-Perez, Ana M; Perez-Clemente, Rosa M; Arbona, Vicent

    2015-01-01

    As sessile organisms, plants cannot escape from adverse conditions and, therefore, they have developed complex responses to the changing environment. Plant responses to abiotic cues involve changes in metabolism, photosynthesis, gene expression, ion levels, etc., and must be perfectly coordinated by phytohormones. The abscisic acid (ABA) is the main phytohormone involved in abiotic stress responses although it is nowadays clear that its signaling pathways are not isolated but interconnected with other hormone signals in complex networks. This article revises molecular mechanisms involved in the crosstalks of ABA with other phytohormones in response to different physiological processes. Moreover, ABA is not a molecule exclusive from plants but it can be found in many other organisms including bacteria, algae, fungi, animals, etc. Interestingly, it can be synthesized and secreted by a variety of human cells. These aspects that confer to the ABA a range of ubiquitous molecule will be also revised in this article.

  18. Phosphoenolpyruvate Carboxykinase in Plants Exhibiting Crassulacean Acid Metabolism 1

    PubMed Central

    Dittrich, P.; Campbell, Wilbur H.; Black, C. C.

    1973-01-01

    Phosphoenolpyruvate carboxykinase has been found in significant activities in a number of plants exhibiting Crassulacean acid metabolism. Thirty-five species were surveyed for phosphoenolpyruvate carboxykinase, phosphoenolpyruvate carboxylase, ribulose diphosphate carboxylase, malic enzyme, and malate dehydrogenase (NAD). Plants which showed high activities of malic enzyme contained no detectable phosphoenolpyruvate carboxykinase, while plants with high activities of the latter enzyme contained little malic enzyme. It is proposed that phosphoenolpyruvate carboxykinase acts as a decarboxylase during the light period, furnishing CO2 for the pentose cycle and phosphoenolpyruvate for gluconeogenesis. Some properties of phosphoenolpyruvate carboxykinase in crude extracts of pineapple leaves were investigated. The enzyme required Mn2+, Mg2+, and ATP for maximum activity. About 60% of the activity could be pelleted, along with chloroplasts and mitochondria, in extracts from leaves kept in the dark overnight. PMID:16658562

  19. Regulation of Nucleosome Stacking and Chromatin Compaction by the Histone H4 N-Terminal Tail-H2A Acidic Patch Interaction.

    PubMed

    Chen, Qinming; Yang, Renliang; Korolev, Nikolay; Liu, Chuan Fa; Nordenskiöld, Lars

    2017-03-16

    Chromatin folding and dynamics are critically dependent on nucleosome-nucleosome interactions with important contributions from internucleosome binding of the histone H4 N-terminal tail K16-R23 domain to the surface of the H2A/H2B dimer. The H4 Lys16 plays a pivotal role in this regard. Using in vitro reconstituted 12-mer nucleosome arrays, we have investigated the mechanism of the H4 N-terminal tail in maintaining nucleosome-nucleosome stacking and mediating intra- and inter-array chromatin compaction, with emphasis on the role of K16 and the positive charge region, R17-R23. Analytical ultracentrifugation sedimentation velocity experiments and precipitation assays were employed to analyze effects on chromatin folding and self-association, respectively. Effects on chromatin folding caused by various mutations and modifications at position K16 in the H4 histone were studied. Additionally, using charge-quenching mutations, we characterized the importance of the interaction of the residues within the H4 positive charge region R17-R23 with the H2A acidic patch of the adjacent nucleosome. Furthermore, crosslinking experiments were conducted to establish the proximity of the basic tail region to the acidic patch. Our data indicate that the positive charge and length of the side chain of H4 K16 are important for its access to the adjacent nucleosome in the process of nucleosome-nucleosome stacking and array folding. The location and orientation of the H4 R17-R23 domain on the H2A/H2B dimer surface of the neighboring nucleosome core particle (NCP) in the compacted chromatin fiber were established. The dominance of electrostatic interactions in maintaining intra-array interaction was demonstrated.

  20. Protect nuclear plant fasteners from boric acid corrosion

    SciTech Connect

    Moisidis, N.; Popescu, M.; Ratiu, M. )

    1992-03-01

    Boric acid corrosion of pump and valve fasteners in pressurized water reactor (PWR) power plants can be prevented by implementing appropriate fastener steel replacement and extended inspections to detect and correct the cause of leakage. In this paper a three-phase corrosion protection program based on system operability, outage-related accessibility, and cost of fastener replacement versus maintenance frequency increase is presented. A selection criteria for fastener material is also presented. Degradation or failure of pressure retaining fasteners at pumps and valves has been reported in several areas exposed to leakage of closures in long-term service. The resulting boric acid corrosion experienced in PWR systems is defined as an accelerated process produced when water evaporates from leaking coolant. The primary detrimental effect of boric acid leakage is wastage (or general dissolution corrosion) of low-alloy carbon steel fasteners.

  1. Organic acids on the growth, anatomical structure, biochemical parameters and heavy metal accumulation of Iris lactea var. chinensis seedling growing in Pb mine tailings.

    PubMed

    Han, Yu-Lin; Huang, Su-Zhen; Yuan, Hai-Yan; Zhao, Jiu-Zhou; Gu, Ji-Guang

    2013-08-01

    The effect of citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) on the growth, anatomical structure, physiological responses and lead (Pb) accumulation of Iris lactea var. chinensis seedling growing in Pb mine tailings for 30 days were studied. Results showed that the dry weights (DW) of roots decreased significantly under both levels of CA. The DWs of leaves and roots treated with 2 mmol/kg EDTA decreased significantly and were 23 and 54 %, respectively, lower than those of the control. The tolerant indexes of I. lactea var. chinensis under all treatments of organic acids were lower than control. The root tip anatomical structure was little affected under the treatments of 2 mmol/kg CA and 2 mmol/kg EDTA compared with control. However, the formation of photosynthesizing cells was inhibited by the treatment of 2 mmol/kg EDTA. The concentrations of chlorophyll a, chlorophyll b and total carotenoids in the leaves treated with 2 mmol/kg EDTA significantly decreased. Higher CA level and lower EDTA level could trigger the synthesis of ascorbic acid and higher level of EDTA could trigger the synthesis of glutathione. CA and EDTA could promote Pb accumulation of I. lactea var. chinensis and Pb concentration in the leaves and roots at 2 mmol/kg EDTA treatment increased significantly and reached to 160.44 and 936.08 μg/g DW, respectively, and 1.8 and 1.6 times higher than those of the control. The results indicated that I. lactea var. chinensis could be used to remediate Pb tailing and the role of EDTA in promoting Pb accumulation was better than CA did.

  2. Tailed bacteriophages: the order caudovirales.

    PubMed

    Ackermann, H W

    1998-01-01

    Tailed bacteriophages have a common origin and constitute an order with three families, named Caudovirales. Their structured tail is unique. Tailed phages share a series of high-level taxonomic properties and show many facultative features that are unique or rare in viruses, for example, tail appendages and unusual bases. They share with other viruses, especially herpesviruses, elements of morphogenesis and life-style that are attributed to convergent evolution. Tailed phages present three types of lysogeny, exemplified by phages lambda, Mu, and P1. Lysogeny appears as a secondary property acquired by horizontal gene transfer. Amino acid sequence alignments (notably of DNA polymerases, integrases, and peptidoglycan hydrolases) indicate frequent events of horizontal gene transfer in tailed phages. Common capsid and tail proteins have not been detected. Tailed phages possibly evolved from small protein shells with a few genes sufficient for some basal level of productive infection. This early stage can no longer be traced. At one point, this precursor phage became perfected. Some of its features were perfect enough to be transmitted until today. It is tempting to list major present-day properties of tailed phages in the past tense to construct a tentative history of these viruses: 1. Tailed phages originated in the early Precambrian, long before eukaryotes and their viruses. 2. The ur-tailed phage, already a quite evolved virus, had an icosahedral head of about 60 nm in diameter and a long non-contractile tail with sixfold symmetry. The capsid contained a single molecule of dsDNA of about 50 kb, and the tail was probably provided with a fixation apparatus. Head and tail were held together by a connector. a. The particle contained no lipids, was heavier than most viruses to come, and had a high DNA content proportional to its capsid size (about 50%). b. Most of its DNA coded for structural proteins. Morphopoietic genes clustered at one end of the genome, with head

  3. Thallium speciation in plant tissues-Tl(III) found in Sinapis alba L. grown in soil polluted with tailing sediment containing thallium minerals.

    PubMed

    Krasnodębska-Ostręga, Beata; Sadowska, Monika; Ostrowska, Sylwia

    2012-05-15

    Besides the dominant species in plants-Tl(I), noticeable amounts of Tl(III) (about 10% of total Tl content) were found in extracts of plants cultivated in the presence of tailing sediments, which are the main source of anthropogenic thallium already present in the environment. It is an important step of gaining knowledge about the detoxification mechanisms developed by Sinapis alba. This plant species is highly tolerant to Tl and it is able to cumulate high amounts of Tl and transport it into the above-ground organs. For more adequate estimation of accumulating abilities of S. alba, the elements' bioavailability was taken into consideration. The obtained bioconcentration factors of Cd (AF=0.6) and Zn (AF=1-2) were significantly lower than of Tl (AF=100-200). The biomass production was similar to the biomass of control cultivation. The results were based on ICP MS measurements of total elements' content and HPLC ICP MS for speciation analysis. The quality of obtained results was evaluated based on the intermethod comparison with voltammetry as a reference method. Comparison of data obtained using ICP MS and electrochemical methods (after a proper chemical treatment) was also used for indication of Tl(III) presence and for proving that Tl(I) was not transferred into Tl(III) during analytical procedures.

  4. Metal concentrations in the soils and native plants surrounding the old flotation tailings pond of the copper mining and smelting complex Bor (Serbia).

    PubMed

    Antonijević, M M; Dimitrijević, M D; Milić, S M; Nujkić, M M

    2012-03-01

    In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As.

  5. A potential plant-derived antifungal acetylenic acid mediates its activity by interfering with fatty acid homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses...

  6. Evaluation of sulfidic mine tailings solidified/stabilized with cement kiln dust and fly ash to control acid mine drainage

    SciTech Connect

    Nehdi, M.; Tariq, A.

    2008-11-15

    In the present research, industrial byproducts, namely, cement kiln dust (CKD) and Class C fly ash (FAC) have been used as candidate materials along with the partial addition of sulfate-resistant cement (SRC) in the Stabilization/solidification of polymetallic sulfidic mine tailings (MT). The effectiveness of S/S was assessed by comparing laboratory experimental values obtained from unconfined compressive strength, hydraulic conductivity and leaching propensity tests of S/S samples with regulatory standards for safe surface disposal of such wastes. Despite general regulatory compliance of compressive strength and hydraulic conductivity, some solidified/stabilized-cured matrices were found unable to provide the required immobilization of pollutants. Solidified/stabilized and 90-day cured mine tailings specimens made with composite binders containing (10% CKD + 10% FAC), (5% SRC + 15% FAC) and (5% SRC + 5% CKD + 10% FAC) significantly impaired the solubility of all contaminants investigated and proved successful in fixing metals within the matrix, in addition to achieving adequate unconfined compressive strength and hydraulic conductivity values, thus satisfying USEPA regulations. Laboratory investigations revealed that, for polymetallic mining waste, leachate concentrations are the most critical factor in assessing the effectiveness of S/S technology.

  7. Abscisic Acid and Abiotic Stress Tolerance in Crop Plants

    PubMed Central

    Sah, Saroj K.; Reddy, Kambham R.; Li, Jiaxu

    2016-01-01

    Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, abscisic acid (ABA) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression. PMID:27200044

  8. Involvement of PKA, CaMKII, PKC, MAPK/ERK and PI3K in the acute antidepressant-like effect of ferulic acid in the tail suspension test.

    PubMed

    Zeni, Ana Lúcia Bertarello; Zomkowski, Andréa Dias Elpo; Maraschin, Marcelo; Rodrigues, Ana Lúcia Severo; Tasca, Carla Inês

    2012-12-01

    Ferulic acid (FA, 4-hydroxy-3-methoxycinnamic acid) is a phytochemical compound naturally present in several plants and foods that is approved as an antioxidant additive and food preservative. It exerts a beneficial action in chronic mild stress-induced depressive-like behavior and produces an acute antidepressant-like effect in the tail suspension test (TST) through the activation of the serotonergic system. This study was aimed at investigating the possible involvement of signaling pathways in the antidepressant-like effect of acute and oral administration of FA, in the TST in mice. The anti-immobility effect of orally administered FA (0.01mg/kg, p.o.) was prevented by pretreatment of mice with H-89 (1μg/site, i.c.v., an inhibitor of PKA), KN-62 (1μg/site, i.c.v., an inhibitor of CaMKII), GF109203X (5ng/site, i.c.v., an inhibitor of PKC), U0126 (5μg/site, i.c.v., an inhibitor of MAPK/ERK) or LY294002 (10nmol/site, i.c.v., an inhibitor of PI3K), all involved with neurotrophic signaling pathways. The results demonstrated that FA exerts antidepressant-like effect in the TST in mice, through the activation of signaling pathways related to neuroplasticity, neurogenesis and cell survival.

  9. Distinct Characteristics of Indole-3-Acetic Acid and Phenylacetic Acid, Two Common Auxins in Plants

    PubMed Central

    Sugawara, Satoko; Mashiguchi, Kiyoshi; Tanaka, Keita; Hishiyama, Shojiro; Sakai, Tatsuya; Hanada, Kousuke; Kinoshita-Tsujimura, Kaori; Yu, Hong; Dai, Xinhua; Takebayashi, Yumiko; Takeda-Kamiya, Noriko; Kakimoto, Tatsuo; Kawaide, Hiroshi; Natsume, Masahiro; Estelle, Mark; Zhao, Yunde; Hayashi, Ken-ichiro; Kamiya, Yuji; Kasahara, Hiroyuki

    2015-01-01

    The phytohormone auxin plays a central role in many aspects of plant growth and development. IAA is the most studied natural auxin that possesses the property of polar transport in plants. Phenylacetic acid (PAA) has also been recognized as a natural auxin for >40 years, but its role in plant growth and development remains unclear. In this study, we show that IAA and PAA have overlapping regulatory roles but distinct transport characteristics as auxins in plants. PAA is widely distributed in vascular and non-vascular plants. Although the biological activities of PAA are lower than those of IAA, the endogenous levels of PAA are much higher than those of IAA in various plant tissues in Arabidopsis. PAA and IAA can regulate the same set of auxin-responsive genes through the TIR1/AFB pathway in Arabidopsis. IAA actively forms concentration gradients in maize coleoptiles in response to gravitropic stimulation, whereas PAA does not, indicating that PAA is not actively transported in a polar manner. The induction of the YUCCA (YUC) genes increases PAA metabolite levels in Arabidopsis, indicating that YUC flavin-containing monooxygenases may play a role in PAA biosynthesis. Our results provide new insights into the regulation of plant growth and development by different types of auxins. PMID:26076971

  10. Signalling of abscisic acid to regulate plant growth.

    PubMed Central

    Himmelbach, A; Iten, M; Grill, E

    1998-01-01

    Abscisic acid (ABA) mediated growth control is a fundamental response of plants to adverse environmental cues. The linkage between ABA perception and growth control is currently being unravelled by using different experimental approaches such as mutant analysis and microinjection experiments. So far, two protein phosphatases, ABI1 and ABI2, cADPR, pH, and Ca2+ have been identified as main components of the ABA signalling pathway. Here, the ABA signal transduction pathway is compared to signalling cascades from yeast and mammalian cells. A model for a bifurcated ABA signal transduction pathway exerting a positive and negative control mechanism is proposed. PMID:9800207

  11. Plants having modified response to ethylene by transformation with an ETR nucleic acid

    DOEpatents

    Meyerowitz, Elliott M.; Chang, Caren; Bleecker, Anthony B.

    2001-01-01

    The invention includes transformed plants having at least one cell transformed with a modified ETR nucleic acid. Such plants have a phenotype characterized by a decrease in the response of at least one transformed plant cell to ethylene as compared to a plant not containing the transformed plant cell. Tissue and/or temporal specificity for expression of the modified ETR nucleic acid is controlled by selecting appropriate expression regulation sequences to target the location and/or time of expression of the transformed nucleic acid. The plants are made by transforming at least one plant cell with an appropriate modified ETR nucleic acid, regenerating plants from one or more of the transformed plant cells and selecting at least one plant having the desired phenotype.

  12. Aminomethylphosphonic acid accumulation in plant species treated with glyphosate.

    PubMed

    Reddy, Krishna N; Rimando, Agnes M; Duke, Stephen O; Nandula, Vijay K

    2008-03-26

    Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. The objective of this study was to determine if there is any correlation of metabolism of glyphosate to AMPA in different plant species and their natural level of resistance to glyphosate. Greenhouse studies were conducted to determine the glyphosate I 50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected leguminous and nonleguminous species treated with glyphosate at respective I 50 rates. Coffee senna [ Cassia occidentalis (L.) Link] was the most sensitive ( I 50 = 75 g/ha) and hemp sesbania [ Sesbania herbacea (P.Mill.) McVaugh] was the most resistant ( I 50 = 456 g/ha) to glyphosate. Hemp sesbania was 6-fold and Illinois bundleflower [ Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.] was 4-fold more resistant to glyphosate than coffee senna. Glyphosate was present in all plant species, and its concentration ranged from 0.308 to 38.7 microg/g of tissue. AMPA was present in all leguminous species studied except hemp sesbania. AMPA concentration ranged from 0.119 to 4.77 microg/g of tissue. Shikimate was present in all plant species treated with glyphosate, and levels ranged from 0.053 to 16.5 mg/g of tissue. Non-glyphosate-resistant (non-GR) soybean accumulated much higher shikimate than glyphosate-resistant (GR) soybean. Although some leguminous species were found to be more resistant to glyphosate than others, and there was considerable variation between species in the glyphosate to AMPA levels found, metabolism of glyphosate to AMPA did not appear to be a common factor in explaining natural resistance levels.

  13. Vegetation successfully prevents oxidization of sulfide minerals in mine tailings.

    PubMed

    Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-07-15

    The oxidization of metal sulfide in tailings causes acid mine drainage. However, it remains unclear whether vegetation prevents the oxidization of metal sulfides. The oxidization characteristics and microbial indices of the tailings in the presence of various plant species were investigated to explore the effects of vegetation on the oxidization of sulfide minerals in tailings. The pH, reducing sulfur, free iron oxides (Fed), chemical oxygen consumption (COC) and biological oxygen consumption (BOC) were measured. Key iron- and sulfur-oxidizing bacteria (Acidithiobacillus spp., Leptospirillum spp. and Thiobacillus spp.) were quantified using real-time PCR. The results indicate that vegetation growing on tailings can effectively prevent the oxidization of sulfide minerals in tailings. A higher pH and reducing-sulfur content and lower Fed were observed in the 0-30 cm depth interval in the presence of vegetation compared to bare tailings (BT). The COC gradually decreased with depth in all of the soil profiles; specifically, the COC rapidly decreased in the 10-20 cm interval in the presence of vegetation but gradually decreased in the BT profiles. Imperata cylindrica (IC) and Chrysopogon zizanoides (CZ) profiles contained the highest BOC in the 10-20 cm interval. The abundance of key iron- and sulfur-oxidizing bacteria in the vegetated tailings were significantly lower than in the BT; in particular, IC was associated with the lowest iron- and sulfur-oxidizing bacterial abundance. In conclusion, vegetation successfully prevented the oxidization of sulfide minerals in the tailings, and Imperata cylindrica is the most effective in reducing the number of iron- and sulfur-oxidizing bacteria and helped to prevent the oxidization of sulfide minerals in the long term.

  14. Defining the needs for non-destructive assay of UF6 feed, product, and tails at gas centrifuge enrichment plants and possible next steps

    SciTech Connect

    Boyer, Brian D; Swinhoe, Martyn T; Moran, Bruce W; Lebrun, Alain

    2009-01-01

    Current safeguards approaches used by the IAEA at gas centrifuge enrichment plants (GCEPs) need enhancement in order to detect undeclared LEU production with adequate detection probability using non destructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of UF{sub 6} bulk material used in the process of enrichment at GCEPS. The inspectors also take destructive assay (DA) samples for analysis off-site which provide accurate, on the order of 0.1 % to 0.5% uncertainty, data on the enrichment of the UF{sub 6} feed, tails, and product. However, DA sample taking is a much more labor intensive and resource intensive exercise for the operator and inspector. Furthermore, the operator must ship the samples off-site to the IAEA laboratory which delays the timeliness of the results and contains the possibility of the loss of the continuity of knowledge of the samples during the storage and transit of the material. Use of the IAEA's inspection sampling algorithm shows that while total sample size is fixed by the total population of potential samples and its intrinsic qualities, the split of the samples into NDA or DA samples is determined by the uncertainties in the NDA measurements. Therefore, the larger the uncertainties in the NDA methods, more of the sample taken must be DA samples. Since the DA sampling is arduous and costly, improvements in NDA methods would reduce the number of DA samples needed. Furthermore, if methods of on-site analysis of the samples could be developed that have uncertainties in the 1-2% range, a lot of the problems inherent in DA sampling could be removed. The use of an unattended system that could give an overview of the entire process giving complementary data on the enrichment process as well as accurate measures of enrichment and weights of the UF{sub 6} feed, tails, and product would be a major step

  15. Ecotechnological approach for consolidation of uranium tailings.

    PubMed

    Soni, Prafulla; Singh, Lal

    2011-07-01

    Present study has been undertaken to consolidate radioactivity in uranium mill tailings at Jaduguda, Jharkhand, India.Tailings that remain after processing of ore are released in tailing ponds specially designed for the purpose. The degraded tailing ponds have been capped with 30 cm. thick soil cover. For cosolidation of radioactivity in the tailings firstly the selected plant species should not have any socioeconomic relevance in that area and secondly, uptake of uranium by selected plants has to be low to avoid its dissemination in any form in environment. Seven native plant species of forestry origin were used for experimental trials. Above ground growth has been measured for two years under ex- situ and in- situ conditions. Distribution and concentration of uranium have been evaluated in tailing pond soil as well as tailings. Uranium uptake by plants has been evaluated and discussed in this paper. The highest concentration of uranium has been found in the order as: in tailings > soil cover on tailings > roots of selected plant species > shoots of all the selected species. These results show that among seven species tried Jatropha gossypifolia and Furcraea foetida have lowest uptake (below detectable limit), while Saccharum spontaneum and Pogostemon benghalense have comparatively higher uptake among the studied species.

  16. Distribution, synthesis, and absorption of kynurenic acid in plants.

    PubMed

    Turski, Michal P; Turska, Monika; Zgrajka, Wojciech; Bartnik, Magdalena; Kocki, Tomasz; Turski, Waldemar A

    2011-05-01

    Kynurenic acid (KYNA) is an endogenous antagonist of the ionotropic glutamate receptors and the α7 nicotinic acetylcholine receptor as well as an agonist of the G-protein-coupled receptor GPR35. In this study, KYNA distribution and synthesis in plants as well as its absorption was researched. KYNA level was determined by means of the high-performance liquid chromatography with fluorescence detection. KYNA was found in leaves, flowers, and roots of tested medicinal herbs: dandelion (Taraxacum officinale), common nettle (Urtica dioica), and greater celandine (Chelidoniummajus). The highest concentration of this compound was detected in leaves of dandelion--a mean value of 0.49 µg/g wet weight. It was shown that KYNA can be synthesized enzymatically in plants from its precursor, L-kynurenine, or absorbed by plants from the soil. Finally, the content of KYNA was investigated in 21 herbal tablets, herbal tea, herbs in sachets, and single herbs in bags. The highest content of KYNA in a maximum daily dose of herbal medicines appeared in St. John's wort--33.75 µg (tablets) or 32.60 µg (sachets). The pharmacological properties of KYNA and its presence in high concentrations in medicinal herbs may suggest that it possesses therapeutic potential, especially in the digestive system and should be considered a new valuable dietary supplement.

  17. Differing Organic Acid Exudation Pattern Explains Calcifuge and Acidifuge Behaviour of Plants

    PubMed Central

    Tyler, Germund; Ström, Lena

    1995-01-01

    Many vascular plant species are unable to colonize calcareous sites. Thus, the floristic composition of adjacent limestone and acid silicate soils differs greatly. The inability of calcifuge plants to establish in limestone sites seems related to a low capacity of such plants to solubilize and absorb Fe or phosphate from these soils. Until now, mechanisms regulating this differing ability of plants to colonize limestone sites have not been elucidated. We propose that contrasting exudation of low-molecular organic acids is a major mechanism involved and show that germinating seeds and young seedlings of limestone plants exude considerably more di- and tricarboxylic acids than calcifuges, which mainly exude monocarboxylic acids. The tricarboxylic citric acid is a powerful extractor of Fe, and the dicarboxylic oxalic acid a very effective extractor of phosphate from limestone soils. Monocarboxylic acids are very weak in these respects. The study is based on ten species from limestone soils and ten species from acid silicate soils. PMID:21247915

  18. Analgesic and Anti-Inflammatory Properties of Gelsolin in Acetic Acid Induced Writhing, Tail Immersion and Carrageenan Induced Paw Edema in Mice

    PubMed Central

    Gupta, Ashok Kumar; Parasar, Devraj; Sagar, Amin; Choudhary, Vikas; Chopra, Bhupinder Singh; Garg, Renu; Ashish; Khatri, Neeraj

    2015-01-01

    Plasma gelsolin levels significantly decline in several disease conditions, since gelsolin gets scavenged when it depolymerizes and caps filamentous actin released in the circulation following tissue injury. It is well established that our body require/implement inflammatory and analgesic responses to protect against cell damage and injury to the tissue. This study was envisaged to examine analgesic and anti-inflammatory activity of exogenous gelsolin (8 mg/mouse) in mice models of pain and acute inflammation. Administration of gelsolin in acetic acid-induced writhing and tail immersion tests not only demonstrated a significant reduction in the number of acetic acid-induced writhing effects, but also exhibited an analgesic activity in tail immersion test in mice as compared to placebo treated mice. Additionally, anti-inflammatory function of gelsolin (8 mg/mouse) compared with anti-inflammatory drug diclofenac sodium (10 mg/kg)] was confirmed in the carrageenan injection induced paw edema where latter was measured by vernier caliper and fluorescent tomography imaging. Interestingly, results showed that plasma gelsolin was capable of reducing severity of inflammation in mice comparable to diclofenac sodium. Analysis of cytokines and histo-pathological examinations of tissue revealed administration of gelsolin and diclofenac sodium significantly reduced production of pro-inflammatory cytokines, TNF-α and IL-6. Additionally, carrageenan groups pretreated with diclofenac sodium or gelsolin showed a marked decrease in edema and infiltration of inflammatory cells in paw tissue. Our study provides evidence that administration of gelsolin can effectively reduce the pain and inflammation in mice model. PMID:26426535

  19. 40 CFR 421.90 - Applicability: Description of the metallurgical acid plants subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... resulting from or associated with the manufacture of by-product sulfuric acid at primary copper smelters... metallurgical acid plants subcategory. 421.90 Section 421.90 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Metallurgical Acid Plants Subcategory § 421.90 Applicability: Description of the...

  20. Is biodegradation of bitumen a source of recalcitrant naphthenic acid mixtures in oil sands tailing pond waters?

    PubMed

    Quagraine, E K; Headley, J V; Peterson, H G

    2005-01-01

    Carboxylic acids are transient metabolites during the mineralization of petroleum hydrocarbons. Crude oils, however, vary in their proportion of the hydrocarbon components. Depending on structure, some carboxylic acid metabolites resist further biodegradation and persist in aquatic systems. During the extraction of oil sands bitumen, recalcitrant carboxylic acid mixtures, collectively referred to as naphthenic acids (NAs), are released into the wastewaters. These waters also contain unrecovered bitumen from the oil sands. The unextracted bitumen is often overlooked as a possible source of the petroleum acids. The present article discusses the literature data on the biotransformation of hydrocarbons in bitumen from oil sands to the corresponding petroleum carboxylic acids. Some insight is given on the mechanism of the biodegradation process. The susceptibility to biodegradation is affected by differences in alicyclic carboxylic acids such as carbon chain length, chain branching, and the oddness or evenness of carbon chain containing the carboxylic group, positions where alkyl groups are substituted on the cyclic ring, geometrical isomerism, and number of cyclic rings.

  1. Comparison of the formation of nicotinic acid conjugates in leaves of different plant species.

    PubMed

    Ashihara, Hiroshi; Yin, Yuling; Katahira, Riko; Watanabe, Shin; Mimura, Tetsuro; Sasamoto, Hamako

    2012-11-01

    There are three metabolic fates of nicotinic acid in plants: (1) nicotinic acid mononucleotide formation for NAD synthesis by the so-called salvage pathway of pyridine nucleotide biosynthesis; (2) nicotinic acid N-glucoside formation; and (3) trigonelline (N-methylnicotinic acid) formation. In the present study, the metabolism of [carbonyl-(14)C]nicotinamide was investigated in leaves of 23 wild plant species. All species readily converted nicotinamide to nicotinic acid, and only a fraction of nicotinic acid was utilised for NAD and NADP synthesis. The remaining nicotinic acid is converted to the nicotinic acid conjugates. Only one plant species, Cycas revoluta, produced both nicotinic acid N-glucoside and trigonelline; the other 22 species produced one or other of the conjugates. The nicotinic acid N-glucoside-forming plants are Cyathea lepifera, Arenga trewmula var. englri, Barringtonia racemosa, Ilex paraguariensis, Angelica japonica, Scaevola taccada and Farfugium japonicum. In contrast, trigonelline is formed in C. lepifera, Ginkgo biloba, Pinus luchuensis, Casuarina equisetifolia, Alocasia odora, Pandanus odoratissimus, Hylocereus undatus, Kalanchoe pinnata, Kalanchoe tubiflora, Populus alba, Garcinia subelliptica, Oxalis corymbosa, Leucaena leucocephala, Vigna marina, Hibiscus tiliaceus and Melicope triphylla. The diversity of nicotinic acid conjugate formation in plants is discussed using these results and our previous investigation involving a few model plants, various crops and ferns. Nicotinic acid N-glucoside formation was restricted mostly to ferns and selected orders of angiosperms, whereas other plants produce trigonelline. In most cases the formation of both nicotinic acid conjugates is incompatible, but some exceptions have been found.

  2. Is acetylcarnitine a substrate for fatty acid synthesis in plants

    SciTech Connect

    Roughan, G. ); Post-Beittenmiller, D.; Ohlrogge, J. ); Browse, J. )

    1993-04-01

    Long-chain fatty acid synthesis from [1-[sup 14]C]acetylcarnitine by chloroplasts isolated from spinach (Spinacia oleracea), pea (Pisum sativum), amaranthus (Amaranthus lividus), or maize (Zea mays) occurred at less than 2% of the rate of fatty acid synthesis from [1-[sup 14]C]acetate irrespective of the maturity of the leaves or whether the plastids were purified using sucrose or Percoll medium. [1-[sup 14]C]Acetylcarnitine was not significantly utilized by highly active chloroplasts rapidly prepared from pea and spinach using methods not involving density gradient centrifugation. [1-[sup 14]C]Acetylcarnitine was recovered quantitatively from chloroplast incubations following 10 min in the light. Unlabeled acetyl-L-carnitine (0.4 mM) did not compete with [1-[sup 14]C]acetate (0.2 mM) as a substrate for fatty acid synthesis by any of the more than 70 chloroplast preparations tested in this study. Carnitine acetyltransferase activity was not detected in any chloroplast preparation and was present in whole leaf homogenates at about 0.1% of the level of acetyl-coenzyme A synthetase activity. When supplied to detached pea shoots and detached spinach, amaranthus, and maize leaves via the transpiration stream, 1 to 4% of the [1-[sup 14]C]acetylcarnitine and 47 to 57% of the [1-[sup 14]C]acetate taken up was incorporated into lipids. Most (78--82%) of the [1-[sup 14]C]acetylcarnitine taken up was recovered intact. It is concluded that acetylcarnitine is not a major precursor for fatty acid synthesis in plants. 29 refs., 5 tabs.

  3. How to Do It. Plant Eco-Physiology: Experiments on Crassulacean Acid Metabolism, Using Minimal Equipment.

    ERIC Educational Resources Information Center

    Friend, Douglas J. C.

    1990-01-01

    Features of Crassulacean Acid Metabolism plants are presented. Investigations of a complex eco-physiological plant adaptation to the problems of growth in an arid environment are discussed. Materials and procedures for these investigations are described. (CW)

  4. New insights into the regulation of plant immunity by amino acid metabolic pathways.

    PubMed

    Zeier, Jürgen

    2013-12-01

    Besides defence pathways regulated by classical stress hormones, distinct amino acid metabolic pathways constitute integral parts of the plant immune system. Mutations in several genes involved in Asp-derived amino acid biosynthetic pathways can have profound impact on plant resistance to specific pathogen types. For instance, amino acid imbalances associated with homoserine or threonine accumulation elevate plant immunity to oomycete pathogens but not to pathogenic fungi or bacteria. The catabolism of Lys produces the immune signal pipecolic acid (Pip), a cyclic, non-protein amino acid. Pip amplifies plant defence responses and acts as a critical regulator of plant systemic acquired resistance, defence priming and local resistance to bacterial pathogens. Asp-derived pyridine nucleotides influence both pre- and post-invasion immunity, and the catabolism of branched chain amino acids appears to affect plant resistance to distinct pathogen classes by modulating crosstalk of salicylic acid- and jasmonic acid-regulated defence pathways. It also emerges that, besides polyamine oxidation and NADPH oxidase, Pro metabolism is involved in the oxidative burst and the hypersensitive response associated with avirulent pathogen recognition. Moreover, the acylation of amino acids can control plant resistance to pathogens and pests by the formation of protective plant metabolites or by the modulation of plant hormone activity.

  5. A Simple Demonstration of Carbon Dioxide Fixation and Acid Production in CAM Plants

    ERIC Educational Resources Information Center

    Walker, John R. L.; McWha, James A.

    1976-01-01

    Described is an experiment investigating carbon dioxide fixation in the dark and the diurnal rhythm of acid production in plants exhibiting Crassulacean Acid Metabolism. Included are suggestions for four further investigations. (SL)

  6. The evaluation of the activity of medicinal remedies of plant and animal origin on the regeneration of the earthworms’ tail segments

    PubMed Central

    Bybin, Viktor Alexandrovich; Stom, Daevard Iosifovich

    2015-01-01

    Now, in the global community there is enough hard recommendation to replace the vertebrate test animals into simpler organisms at the development, testing, and evaluation of the quality pharmaceuticals. The feature of planarian to regenerate in new individual planarian from a piece, which is only 1/7 of the original animal, allowed to create the alternative methods of testing of drugs, dietary supplements, water quality, influence of electromagnetic fields, and other radiations. The tests on planarian can replace the ones that are held today on mammals. However, the lacks of the bioassays based on the planarian regeneration are the need for complex and expensive video equipment for recording the regrowth of worms’ body, the difficulties of culturing of flatworms and fairly long period of response. These difficulties can be avoided by using another group of the worms of type Annelida. The new individual can be fully recovered only from the front half of the body in many species of earthworms. Thus, the influence of the pharmaceuticals from earthworms, mummy, and Orthilia secunda on the ability of earthworms to regenerate lost tail segments has been investigated. The relations of the activity of preparations tested with doses and the time of the storage have been revealed. The principal possibility of applicability of the test reaction studied as a way to evaluate the effects and quality of remedies based on medicinal plants and earthworms has been shown. PMID:26692755

  7. Perception of the plant immune signal salicylic acid.

    PubMed

    Yan, Shunping; Dong, Xinnian

    2014-08-01

    Salicylic acid (SA) plays a central role in plant innate immunity. The diverse functions of this simple phenolic compound suggest that plants may have multiple SA receptors. Several SA-binding proteins have been identified using biochemical approaches. However, genetic evidence supporting that they are the bona fide SA receptors has not been forthcoming. Mutant screens revealed that NPR1 is a master regulator of SA-mediated responses. Although NPR1 cannot bind SA in a conventional ligand-binding assay, its homologs NPR3 and NPR4 bind SA and function as SA receptors. During pathogen challenge, the SA gradient generated at the infection site is sensed by NPR3 and NPR4, which serve as the adaptors for the Cullin 3-based E3 ubiquitin ligase to regulate NPR1 degradation. Consequently, NPR1 is degraded at the infection site to remove its inhibition on effector-triggered cell death and defense, whereas NPR1 accumulates in neighboring cells to promote cell survival and SA-mediated resistance.

  8. A perspective of stepwise utilisation of Bayer red mud: Step two--Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation.

    PubMed

    Huang, Yanfang; Chai, Wencui; Han, Guihong; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

    2016-04-15

    The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti(4+), Al(3+) and Fe(3+), and the mechanism of selectively Fe(3+) removal using [Hbet][Tf2N] as precipitating reagent were discussed. The extracting of Ti(4+), Al(3+) and Fe(3+) in concentrated H2SO4 is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti(4+) is approximately 92.3%, whereas Al(3+) and Fe(3+) leaching are respectively 75.8% and 84.2%. [Hbet][Tf2N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti(4+), whereas the dosage of precipitating reagent is that for Al(3+) recovery. The maximum flotation recovery of Ti(4+) is 92.7%, whereas the maximum Al(3+) recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti(4+) of 15.5g/L, Al(3+) of 30.4g/L and Fe(3+) of 0.48g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation.

  9. Pullulanibacillus uraniitolerans sp. nov., an acidophilic, U(VI)-resistant species isolated from an acid uranium mill tailing effluent and emended description of the genus Pullulanibacillus.

    PubMed

    Pereira, Sónia G; Albuquerque, Luciana; Nobre, M Fernanda; Tiago, Igor; Veríssimo, António; Pereira, Alcides; da Costa, Milton S

    2013-01-01

    Two Gram-positive-staining, rod-shaped, endospore-forming isolates (UG-2(T) and UG-3), with an optimum growth temperature of around 37 °C and an optimum pH for growth of about 4, were recovered from an acidic effluent of the uranium mill tailing at Urgeiriça in Central Portugal. On the basis of 16S rRNA gene sequence similarity, the strains belonged to the family Sporolactobacillaceae and were closely related to Pullulanibacillus naganoensis ATCC 53909(T) (97.9 %). Unlike P. naganoensis, strains UG-2(T) and UG-3 grew in medium containing up to 5000 p.p.m. U(VI) but did not hydrolyse pullulan. Chemotaxonomic data also supported the affiliation of strains UG-2(T) and UG-3 to the genus Pullulanibacillus. Physiological and biochemical tests along with fatty acid composition allowed differentiation of strains UG-2(T) and UG-3 from P. naganoensis. It is suggested that strains UG-2(T) and UG-3 represent a novel species, for which the name Pullulanibacillus uraniitolerans is proposed; the type strain is UG-2(T) (=DSM 19429(T) = LMG 24205(T)). An emended description of the genus Pullulanibacillus is also proposed.

  10. A tailed PCR procedure for cost-effective, two-order multiplex sequencing of candidate genes in polyploid plants.

    PubMed

    Gholami, Mahmood; Bekele, Wubishet A; Schondelmaier, Joerg; Snowdon, Rod J

    2012-08-01

    Complex polyploid crop genomes can be recalcitrant towards conventional DNA sequencing approaches for allele mining in candidate genes for valuable traits. In the past, this has greatly complicated the transfer of knowledge on promising candidate genes from model plants to even closely related polyploid crops. Next-generation sequencing offers diverse solutions to overcome such difficulties. Here, we present a method for multiplexed 454 sequencing in gene-specific PCR amplicons that can simultaneously address multiple homologues of given target genes. We devised a simple two-step PCR procedure employing a set of barcoded M13/T7 universal fusion primers that enable a cost-effective and efficient amplification of large numbers of target gene amplicons. Sequencing-ready amplicons are generated that can be simultaneously sequenced in pools comprising multiple amplicons from multiple genotypes. High-depth sequencing allows resolution of the resulting sequence reads into contigs representing multiple homologous loci, with only insignificant off-target capture of paralogues or PCR artefacts. In a case study, the procedure was tested in the complex polyploid genome of Brassica napus for a set of nine genes identified in Arabidopsis as candidates for regulation of seed development and oil content. Up to six copies of these genes were expected in B. napus. SNP discovery was performed by pooled multiplex sequencing of 30 amplicons in 20 diverse B. napus accessions with interesting trait variation for oil content, providing a basis for comparative mapping to relevant quantitative trait loci and for subsequent marker-assisted breeding.

  11. Artificial inoculation-perspectives in tailings phytostabilization.

    PubMed

    Petrisor, Ioana G; Dobrota, Smaranda; Komnitsas, Kostas; Lazar, Ioan; Kuperberg, J Michael; Serban, Mihai

    2004-01-01

    Intensive mining and processing activities worldwide resulted in the generation of huge amounts of waste (tailings), generally characterized as toxic, radioactive, and/or hazardous. The exposure potential and, hence, the risk posed by such wastes is enhanced by a general lack of vegetation. Phytostabilization has proven to be efficient in reducing this risk. However, establishing vegetation on tailing dumps may be expensive due to the intensive use of amendments and chemical fertilizers. In this article, investigations on artificial inoculation of mine tailings with bacterial strains as a means to improve the development of vegetative covers and reduce application cost by eliminating chemical fertilization are presented and discussed. The development of plants and microbial communities from tailings, as well as the impact of inoculation on metal uptake in plants, were studied. Experiments were carried out in greenhouse using two types of mine tailings (phosphogypsum and sulphidic tailings) from the Romanian Black Sea coast. Indigenous herbaceous plants were cultivated on tailings with the addition of chemical fertilizers versus bacterial inoculation. After a 6-month experimental period, excellent plant growth, which is associated with a rich microbial community, was observed in all inoculated treatments, in contrast with poor plant growth and microbiota from the chemical fertilization treatments alone. Additionally, artificial inoculation improved plant resistance to heavy metals by reducing the uptake of some toxic metals. Once a rich microbial community is established, inoculation may be discontinued. Based on these results, efficient and cost-effective phytostabilization schemes can be proposed.

  12. L-Ascorbic Acid: A Multifunctional Molecule Supporting Plant Growth and Development

    PubMed Central

    Gallie, Daniel R.

    2013-01-01

    L-Ascorbic acid (vitamin C) is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps reflecting the importance of this molecule to plant health. Given the importance of ascorbic acid to human nutrition, several technologies have been developed to increase the ascorbic acid content of plants through the manipulation of biosynthetic or recycling pathways. This paper provides an overview of these approaches as well as the consequences that changes in ascorbic acid content have on plant growth and function. Discussed is the capacity of plants to tolerate changes in ascorbic acid content. The many functions that ascorbic acid serves in plants, however, will require highly targeted approaches to improve their nutritional quality without compromising their health. PMID:24278786

  13. Amino acid export in plants: a missing link in nitrogen cycling.

    PubMed

    Okumoto, Sakiko; Pilot, Guillaume

    2011-05-01

    The export of nutrients from source organs to parts of the body where they are required (e.g. sink organs) is a fundamental biological process. Export of amino acids, one of the most abundant nitrogen species in plant long-distance transport tissues (i.e. xylem and phloem), is an essential process for the proper distribution of nitrogen in the plant. Physiological studies have detected the presence of multiple amino acid export systems in plant cell membranes. Yet, surprisingly little is known about the molecular identity of amino acid exporters, partially due to the technical difficulties hampering the identification of exporter proteins. In this short review, we will summarize our current knowledge about amino acid export systems in plants. Several studies have described plant amino acid transporters capable of bi-directional, facilitative transport, reminiscent of activities identified by earlier physiological studies. Moreover, recent expansion in the number of available amino acid transporter sequences have revealed evolutionary relationships between amino acid exporters from other organisms with a number of uncharacterized plant proteins, some of which might also function as amino acid exporters. In addition, genes that may regulate export of amino acids have been discovered. Studies of these putative transporter and regulator proteins may help in understanding the elusive molecular mechanisms of amino acid export in plants.

  14. D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants)

    SciTech Connect

    Loewus, F.A. . Inst. of Biological Chemistry); Seib, P.A. . Dept. of Grain Science and Industry)

    1991-01-01

    The origin of oxalate in plants has received considerable attention and glycolate metabolism has been generally regarded as a prime precursor candidate although studies on the metabolism of L-ascorbic acid single out that plant constituent as well. Experiments with oxalate-accumulating plants that contain little or no tartaric acid revealed the presence of a comparable L-ascorbic acid metabolism with the exception that the cleavage products were oxalic acid and L-threonic acid or products of L-threonic acid metabolism. A reasonable mechanism for cleavage of L-ascorbic acid at the endiolic bond is found in studies on the photooxygenation of L-ascorbic acid. Presumably, analogs of L-ascorbic acid that differ only in the substituent at C4 also form a hydroperoxide in the presence of alkaline hydrogen peroxide and subsequently yield oxalic acid and the corresponding aldonic acid or its lactone. We became interested in such a possibility when we discovered that L-ascorbic acid was rare or absent in certain yeasts and fungi whereas a L-ascorbic acid analog, D-glycero-pent-2-enono- 1,4-lactone (D-erythroascorbic acid), was present. It has long been known that oxalate occurs in yeasts and fungi and its production plays a role in plant pathogenesis. As to the biosynthetic origin of fungal oxalic acid there is little information although it is generally assumed that oxaloacetate or possibly, glycolate, might be that precursor.

  15. D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants). Final report

    SciTech Connect

    Loewus, F.A.; Seib, P.A.

    1991-12-31

    The origin of oxalate in plants has received considerable attention and glycolate metabolism has been generally regarded as a prime precursor candidate although studies on the metabolism of L-ascorbic acid single out that plant constituent as well. Experiments with oxalate-accumulating plants that contain little or no tartaric acid revealed the presence of a comparable L-ascorbic acid metabolism with the exception that the cleavage products were oxalic acid and L-threonic acid or products of L-threonic acid metabolism. A reasonable mechanism for cleavage of L-ascorbic acid at the endiolic bond is found in studies on the photooxygenation of L-ascorbic acid. Presumably, analogs of L-ascorbic acid that differ only in the substituent at C4 also form a hydroperoxide in the presence of alkaline hydrogen peroxide and subsequently yield oxalic acid and the corresponding aldonic acid or its lactone. We became interested in such a possibility when we discovered that L-ascorbic acid was rare or absent in certain yeasts and fungi whereas a L-ascorbic acid analog, D-glycero-pent-2-enono- 1,4-lactone (D-erythroascorbic acid), was present. It has long been known that oxalate occurs in yeasts and fungi and its production plays a role in plant pathogenesis. As to the biosynthetic origin of fungal oxalic acid there is little information although it is generally assumed that oxaloacetate or possibly, glycolate, might be that precursor.

  16. Response of amino acids in hindlimb muscles to recovery from hypogravity and unloading by tail-cast suspension

    NASA Technical Reports Server (NTRS)

    Tischler, M. E.; Henriksen, E. J.; Jacob, S.; Cook, P. H.

    1985-01-01

    Concentrations of glutamine, glutamate, aspartate (+ asparagine) and alanine were compared in hindlimb muscles of SL-3 and ground control rats. Alanine was lower in the soleus of flown rats but not of suspended animals, with no response in other muscles except a slight increase in the unloaded plantaris. With recovery, alanine in the soleus was elevated. Since no differences in alanine metabolism were found by isolated muscle, changes in muscle alanine are probably due to altered body use of this amino acid leading to varied plasma levels.

  17. Responses of amino acids in hindlimb muscles to recovery from hypogravity and unloading by tail-cast suspension

    NASA Technical Reports Server (NTRS)

    Tischler, M. E.; Henriksen, E. J.; Jacob, S.; Cook, P. H.

    1985-01-01

    Amino acids were assayed in muscles from rats exposed to 7 days of hypogravity and 12 h of gravity (F) or 6 days of suspension with (R) or without (H) 12 h of loading. In these groups, lower aspartate was common only to the soleus (SOL) relative to control muscles, the smallest difference being in group R. This difference in aspartate for F and H, but not for R, correlated with lower malate suggesting diminution of citric acid cycle intermediates. The R SOL value was increased over the H SOL. Therefore desite 12 h of loading, the F SOL was more comparable to the H SOL. The role of stress in preventing recovery of the F SOL was apparent from the ratios of glutamine/glutamate. Synthesis of glutamine is enhanced by glucocorticoids and is reflected by an increased ratio. In 5 of the 6 F muscles studied, this ratio was greater than in controls. In contrast, the ratio in all R muscles was similar to controls and showed recovery from the values in H muscles. Hence the post-flight treatment of F rats may have produced additional stress. Despite this stress, in some respects the SOL responses to hypogravity were similar to its responses to unloding by suspension.

  18. Deviation from niche optima affects the nature of plant-plant interactions along a soil acidity gradient.

    PubMed

    He, Lei; Cheng, Lulu; Hu, Liangliang; Tang, Jianjun; Chen, Xin

    2016-01-01

    There is increasing recognition of the importance of niche optima in the shift of plant-plant interactions along environmental stress gradients. Here, we investigate whether deviation from niche optima would affect the outcome of plant-plant interactions along a soil acidity gradient (pH = 3.1, 4.1, 5.5 and 6.1) in a pot experiment. We used the acid-tolerant species Lespedeza formosa Koehne as the neighbouring plant and the acid-tolerant species Indigofera pseudotinctoria Mats. or acid-sensitive species Medicago sativa L. as the target plants. Biomass was used to determine the optimal pH and to calculate the relative interaction index (RII). We found that the relationships between RII and the deviation of soil pH from the target's optimal pH were linear for both target species. Both targets were increasingly promoted by the neighbour as pH values deviated from their optima; neighbours benefitted target plants by promoting soil symbiotic arbuscular mycorrhizal fungi, increasing soil organic matter or reducing soil exchangeable aluminium. Our results suggest that the shape of the curve describing the relationship between soil pH and facilitation/competition depends on the soil pH optima of the particular species.

  19. Plant/soil concentration ratios of 226Ra for contrasting sites around an active U mine-mill.

    PubMed

    Ibrahim, S A; Whicker, F W

    1988-12-01

    Concentrations of 226Ra were determined in native vegetation and underlying substrate (soil and tailings) at various sites around a conventional open-pit, acid leach U production operation in Wyoming. Plant/soil concentration ratios (CRs) for 226Ra were estimated for various sites, including weathered tailings; a tailings impoundment shoreline; downwind from exposed tailings; a mine overburden reclamation area; and several background locations. Radium-226 concentrations for vegetation and substrate and CR values from the perturbed sites were elevated above background. The highest vegetation concentration (1.3 Bq g-1) was found in a grass which had invaded exposed, weathered tailings. Levels of 226Ra in soil and vegetation and CR values decreased with distance from the tailings impoundment edge. CR values varied significantly among sites, but few differences were found between plant species groups. The observed CR values ranged from 0.07 at the background and reclamation areas to 0.4 downwind from the tailings area. Average CR values for plants growing on exposed tailings and within one meter from the impoundment edge were 0.15 and 0.3, respectively. CR values of 226Ra for plants on tailings substrates were comparatively low in contrast to other radionuclides in the U chain. We speculate that in the case of sulfuric acid leached tailings-derived material, 226Ra is sequestered as sulfate, which is highly insoluble relative to the sulfates of the other elements (e.g., U and Th) resulting in reduced availability for plant uptake.

  20. How does the multifaceted plant hormone salicylic acid combat disease in plants and are similar mechanisms utilized in humans?

    PubMed

    Dempsey, D'Maris Amick; Klessig, Daniel F

    2017-03-23

    Salicylic acid (SA) is an important plant hormone that regulates many aspects of plant growth and development, as well as resistance to (a)biotic stress. Efforts to identify SA effector proteins have revealed that SA binds to and alters the activity of multiple plant proteins-this represents a shift from the paradigm that hormones mediate their functions via one or a few receptors. SA and its derivatives also have multiple targets in animals; some of these proteins, like their plant counterparts, are associated with pathological processes. Together, these findings suggest that SA exerts its defense-associated effects in both kingdoms via a large number of targets.

  1. Distribution of a Fatty Acid Cyclase Enzyme System in Plants 1

    PubMed Central

    Vick, Brady A.; Zimmermann, Don C.

    1979-01-01

    Extracts from tissues of 24 plant species were tested for the enzyme that catalyzes the conversion of 13-l-hydroperoxy-cis-9,15-trans-11-octadecatrienoic acid to the cyclic fatty acid 12-oxo-cis-10,15-phytodienoic acid. The enzyme was detected in 15 of the 24 tissues examined, and was demonstrated in seedlings, leaves, and fruits. PMID:16660932

  2. Effects of three low-molecular-weight organic acids (LMWOAs) and pH on the mobilization of arsenic and heavy metals (Cu, Pb, and Zn) from mine tailings.

    PubMed

    Wang, Suiling; Mulligan, Catherine N

    2013-02-01

    Natural organic acids may play an important role in influencing the mobility of toxic contaminants in the environment. The mobilization of arsenic (As) and heavy metals from an oxidized Pb-Zn mine tailings sample in the presence of three low-molecular-weight organic acids, aspartic acid, cysteine, and succinic acid, was investigated at a mass ratio of 10 mg organic additive/g mine tailings in this study. The effect of pH was also evaluated. The mine tailings sample, containing elevated levels of As (2,180 mg/kg), copper (Cu, 1,100 mg/kg), lead (Pb, 12,860 mg/kg), and zinc (Zn, 5,075 mg/kg), was collected from Bathurst, New Brunswick, Canada. It was found that the organic additives inhibited As and heavy metal mobilization under acidic conditions (at pH 3 or 5), but enhanced it under neutral to alkaline conditions (at pH above 7) through forming aqueous organic complexes. At pH 11, As, Cu, Pb, and Zn were mobilized mostly by the organic additives, 45, 46, 1,660, and 128 mg/kg by aspartic acid, 31, 28, 1,040, and 112 mg/kg by succinic acid, and 53, 38, 2,020, and 150 mg/kg by cysteine, respectively, whereas those by distilled water were 6, 16, 260, and 52 mg/kg, respectively. It was also found that the mobilization of As and the heavy metals was closely correlated, and both were closely correlated to Fe mobilization. Arsenic mobilization by the three LMWOAs was found to be consistent with the order of the stability of Fe-, Cu-, Pb-, and Zn-organic ligand complexes. The organic acids might be used potentially in the natural attenuation and remediation of As and heavy metal-contaminated sites.

  3. Fumaric acid: an overlooked form of fixed carbon in Arabidopsis and other plant species

    SciTech Connect

    Chia, D.W.; Yoder, T.J.; Reiter, W.D.; Gibson, S.I.

    2000-10-01

    Photoassimilates are used by plants for production of energy, as carbon skeletons and in transport of fixed carbon between different plant organs. Many studies have been devoted to characterizing the factors that. regulate photoassimilate concentrations in different plant species. Most studies examining photoassimilate concentrations in C{sub 3} plants have focused on analyzing starch and soluble sugars. However, work presented here demonstrates that a number of C{sub 3} plants, including the popular model organism Arabidopsis thaliana (L.) Heynh., and agriculturally important plants, such as soybean [Glycine ma (L.) Merr.], contain significant quantities of furnaric acid. In fact, furnaric acid can accumulate to levels of several mg per g fresh weight in A-abidopsis leaves, often exceeding starch and soluble sugar levels. Furnaric acid is a component of the tricarboxylic acid cycle and, like starch and soluble sugars, can be metabolized to yield energy and carbon skeletons for production of other compounds. Fumaric acid concentrations increase with plant age and light intensity in Arabidopsis leaves. Arabidopsis phloem exudates contain significant quantities of fumaric acid, raising the possibility that fumaric acid may function in carbon transport.

  4. Abscisic acid and other plant hormones: Methods to visualize distribution and signaling.

    PubMed

    Waadt, Rainer; Hsu, Po-Kai; Schroeder, Julian I

    2015-12-01

    The exploration of plant behavior on a cellular scale in a minimal invasive manner is key to understanding plant adaptations to their environment. Plant hormones regulate multiple aspects of growth and development and mediate environmental responses to ensure a successful life cycle. To monitor the dynamics of plant hormone actions in intact tissue, we need qualitative and quantitative tools with high temporal and spatial resolution. Here, we describe a set of biological instruments (reporters) for the analysis of the distribution and signaling of various plant hormones. Furthermore, we provide examples of their utility for gaining novel insights into plant hormone action with a deeper focus on the drought hormone abscisic acid.

  5. Progress and prospects for phosphoric acid fuel cell power plants

    SciTech Connect

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J.

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

  6. Effects and mechanism of acid rain on plant chloroplast ATP synthase.

    PubMed

    Sun, Jingwen; Hu, Huiqing; Li, Yueli; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-09-01

    Acid rain can directly or indirectly affect plant physiological functions, especially photosynthesis. The enzyme ATP synthase is the key in photosynthetic energy conversion, and thus, it affects plant photosynthesis. To clarify the mechanism by which acid rain affects photosynthesis, we studied the effects of acid rain on plant growth, photosynthesis, chloroplast ATP synthase activity and gene expression, chloroplast ultrastructure, intracellular H(+) level, and water content of rice seedlings. Acid rain at pH 4.5 remained the chloroplast structure unchanged but increased the expression of six chloroplast ATP synthase subunits, promoted chloroplast ATP synthase activity, and increased photosynthesis and plant growth. Acid rain at pH 4.0 or less decreased leaf water content, destroyed chloroplast structure, inhibited the expression of six chloroplast ATP synthase subunits, decreased chloroplast ATP synthase activity, and reduced photosynthesis and plant growth. In conclusion, acid rain affected the chloroplast ultrastructure, chloroplast ATPase transcription and activity, and P n by changing the acidity in the cells, and thus influencing the plant growth and development. Finally, the effects of simulated acid rain on the test indices were found to be dose-dependent.

  7. [Advances in studies of absorption and utilization of amino acids by plants: A review].

    PubMed

    Cao, Xiao-chuang; Wu, Liang-huan; Ma, Qing-xu; Jin, Qian-yu

    2015-03-01

    Plant can directly take up the intact amino acids, thus bypass the microbial mineralization of organic nitrogen. As an excellent carbon and nitrogen source, there exists competition for amino acid absorption between plant roots.and soil microorganisms. And the total flux of amino acids in soil may be enormous due to the extensive sources and short half-life. Studies on amino acid nitrogen nutritional contribution for plant by the technique of nitrogen isotopic tracer, has become a research topic in recent years ,which will help us better understand the principle of soil fertility. This paper summarized the recent researches on amino acid morphological characteristics in soil and its metabolic mechanism and nitrogen nutritional contribution for plant in different ecosystems, and discussed the present status and development trend of the amino acid circulation mechanism in the plant-soil-microorganism ecosystem and its bioavailability for plant. Finally, the topics of environmental regulating mechanism of amino acid bioavailability, amino acid carbon-nitrogen metabolism, and how to improve the field organic nitrogen management were all the core issues to be resolved.

  8. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways.

    PubMed

    Mur, Luis A J; Prats, Elena; Pierre, Sandra; Hall, Michael A; Hebelstrup, Kim H

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used.

  9. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways

    PubMed Central

    Mur, Luis A. J.; Prats, Elena; Pierre, Sandra; Hall, Michael A.; Hebelstrup, Kim H.

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used. PMID:23818890

  10. Chemical and mineralogical changes of waste and tailings from the Murgul Cu deposit (Artvin, NE Turkey): implications for occurrence of acid mine drainage.

    PubMed

    Sağlam, Emine Selva; Akçay, Miğraç

    2016-04-01

    Being one of the largest copper-producing resources in Turkey, the Murgul deposit has been a source of environmental pollution for very long time. Operated through four open pits with an annual production of about 3 million tons of ore at an average grade of about 0.5% Cu, the deposit to date has produced an enormous pile of waste (exceeding 100 million tons) with tailings composed of 36 % SiO2, 39% Fe2O3 and 32% S, mainly in the form of pyrite and quartz. Waters in the vicinity of the deposit vary from high acid-acid (2.71-3.85) and high-extremely metal rich (34.48-348.12 mg/l in total) in the open pits to near neutral (6.51-7.83) and low metal (14.39-973.52 μg/l in total) in downstream environments. Despite low metal contents and near neutral pH levels of the latter, their suspended particle loads are extremely high and composed mainly of quartz and clay minerals with highly elevated levels of Fe (3.5 to 24.5% Fe2O3; 11% on average) and S (0.5 to 20.6% S; 7% on average), showing that Fe is mainly in the form of pyrite and lesser hematite. They also contain high concentrations of As, Au, Ba, Cu, Pb, and Zn. Waters collected along the course of polluted drainages are supersaturated with respect to Fe phases such as goethite, hematite, maghemite, magnetite, schwertmannite and ferrihydrite. Secondary phases such as Fe-sulphates are only found near the pits, but not along the streams due to neutral pH conditions, where pebbles are covered and cemented by Fe-oxides and hydroxides indicating that oxidation of pyrite has taken place especially at times of low water load. It follows, then, that the pyrite-rich sediment load of streams fed by the waste of the Murgul deposit is currently a big threat to the aquatic life and environment and will continue to be so even after the closure of the deposit. In fact, the oxidation will be enhanced and acidity increased due to natural conditions, which necessitates strong remedial actions to be taken.

  11. Variation in the Carbon Isotope Composition of a Plant with Crassulacean Acid Metabolism

    PubMed Central

    Lerman, J. C.; Deleens, Eliane; Nato, Aimé; Moyse, Alexis

    1974-01-01

    The content of 13C varies in plants with Crassulacean acid metabolism. Differences up to 3.5‰ in the 13C/12C ratios were observed between leaves of different age in the same plant of Bryophyllum daigremontianum. Soluble and insoluble carbon in the same leaf differed up to 8‰, the largest difference occurring in the leaves with the highest Crassulacean acid metabolism activity. Models to account for the isotope discrimination by C3, C4, and Crassulacean acid metabolism plants are proposed. PMID:16658746

  12. Experimental and kinetic modelling studies on the acid-catalysed hydrolysis of the water hyacinth plant to levulinic acid.

    PubMed

    Girisuta, B; Danon, B; Manurung, R; Janssen, L P B M; Heeres, H J

    2008-11-01

    A comprehensive experimental and modelling study on the acid-catalysed hydrolysis of the water hyacinth plant (Eichhornia crassipes) to optimise the yield of levulinic acid (LA) is reported (T=150-175 degrees CH2SO4 = 0.1-1M, water hyacinth intake=1-5wt%). At high acid concentrations (>0.5M), LA was the major organic acid whereas at low acid concentrations (<0.1M) and high initial intakes of water hyacinth, the formation of propionic acid instead of LA was favoured. The highest yield of LA was 53mol% (35wt%) based on the amount of C6-sugars in the water hyacinth (T=175 degrees CH2SO4 =1M , water hyacinth intake=1wt%). The LA yield as a function of the process conditions was modelled using a kinetic model originally developed for the acid-catalysed hydrolysis of cellulose and good agreement between the experimental and modelled data was obtained.

  13. Biological treatment options for consolidated tailings release waters

    SciTech Connect

    Gunter, C.P.; Nix, P.G.; Sander, B.; Knezevic, Z.

    1995-12-31

    Suncor Inc., Oil Sands Group, operates a large oil sands mining and extraction operation in northeastern Alberta. The extraction plant produces large volumes of a tailings slurry which resists dewatering and treatment, and is toxic to aquatic organisms. Consolidated tailings (CT) technology is used to treat tailings by either acid/lime or gypsum and enhances the possibility of treating residual fine tails in a ``dry`` land reclamation scenario and treating the release water in a wastewater treatment reclamation scenario. The objective was to assess the treatability of CT release water (i.e., the reduction of acute and chronic toxicities to trout, Ceriodaphnia, and bacteria) in bench-scale biological treatment systems. Microtox{reg_sign} IC20 test showed complete detoxification for the gypsum CT release water within 3 to 5 weeks compared with little reduction in toxicity for dyke drainage. Acute toxicity (fish) and chronic toxicity (Ceriodaphnia, bacterial) was removed from both CT release waters. Phosphate and aeration enhanced detoxification rates. Concentrations of naphthenic acids (an organic toxicant) were not reduced, but levels of dissolved organic compounds decreased faster than was the case for dyke drainage water, indicating that some of the organic compounds in both acid/lime and gypsum CT waters were more biodegradable. There was a pattern of increasing toxicity for dyke drainage water which confirmed observations during field-scale testing in the constructed wetlands and which was not observed for CT release waters. Acid/lime and gypsum CT water can be treated biologically in either an aeration pond, constructed wetlands, or a combination of both thereby avoiding the expense of long-term storage and/or conventional waste treatment systems.

  14. The influence of humic acids derived from earthworm-processed organic wastes on plant growth.

    PubMed

    Atiyeh, R M; Lee, S; Edwards, C A; Arancon, N Q; Metzger, J D

    2002-08-01

    Some effects of humic acids, formed during the breakdown of organic wastes by earthworms (vermicomposting), on plant growth were evaluated. In the first experiment, humic acids were extracted from pig manure vermicompost using the classic alkali/acid fractionation procedure and mixed with a soilless container medium (Metro-Mix 360), to provide a range of 0, 50, 100, 150, 200, 250, 500, 1,000, 2,000, and 4,000 mg of humate per kg of dry weight of container medium, and tomato seedlings were grown in the mixtures. In the second experiment, humates extracted from pig manure and food wastes vermicomposts were mixed with vermiculite to provide a range of 0, 50, 125, 250, 500, 1,000, and 4,000 mg of humate per kg of dry weight of the container medium, and cucumber seedlings were grown in the mixtures. Both tomato and cucumber seedlings were watered daily with a solution containing all nutrients required to ensure that any differences in growth responses were not nutrient-mediated. The incorporation of both types of vermicompost-derived humic acids, into either type of soilless plant growth media, increased the growth of tomato and cucumber plants significantly, in terms of plant heights, leaf areas, shoot and root dry weights. Plant growth increased with increasing concentrations of humic acids incorporated into the medium up to a certain proportion, but this differed according to the plant species, the source of the vermicompost, and the nature of the container medium. Plant growth tended to be increased by treatments of the plants with 50-500 mg/kg humic acids, but often decreased significantly when the concentrations of humic acids derived in the container medium exceeded 500-1,000 mg/kg. These growth responses were most probably due to hormone-like activity of humic acids from the vermicomposts or could have been due to plant growth hormones adsorbed onto the humates.

  15. Evidence for Amino Acid Snorkeling from a High-Resolution, In Vivo Analysis of Fis1 Tail-Anchor Insertion at the Mitochondrial Outer Membrane.

    PubMed

    Keskin, Abdurrahman; Akdoğan, Emel; Dunn, Cory D

    2017-02-01

    Proteins localized to mitochondria by a carboxyl-terminal tail anchor (TA) play roles in apoptosis, mitochondrial dynamics, and mitochondrial protein import. To reveal characteristics of TAs that may be important for mitochondrial targeting, we focused our attention upon the TA of the Saccharomyces cerevisiae Fis1 protein. Specifically, we generated a library of Fis1p TA variants fused to the Gal4 transcription factor, then, using next-generation sequencing, revealed which Fis1p TA mutations inhibited membrane insertion and allowed Gal4p activity in the nucleus. Prompted by our global analysis, we subsequently analyzed the ability of individual Fis1p TA mutants to localize to mitochondria. Our findings suggest that the membrane-associated domain of the Fis1p TA may be bipartite in nature, and we encountered evidence that the positively charged patch at the carboxyl terminus of Fis1p is required for both membrane insertion and organelle specificity. Furthermore, lengthening or shortening of the Fis1p TA by up to three amino acids did not inhibit mitochondrial targeting, arguing against a model in which TA length directs insertion of TAs to distinct organelles. Most importantly, positively charged residues were more acceptable at several positions within the membrane-associated domain of the Fis1p TA than negatively charged residues. These findings, emerging from the first high-resolution analysis of an organelle targeting sequence by deep mutational scanning, provide strong, in vivo evidence that lysine and arginine can "snorkel," or become stably incorporated within a lipid bilayer by placing terminal charges of their side chains at the membrane interface.

  16. Evidence for Amino Acid Snorkeling from a High-Resolution, In Vivo Analysis of Fis1 Tail-Anchor Insertion at the Mitochondrial Outer Membrane

    PubMed Central

    Keskin, Abdurrahman; Akdoğan, Emel; Dunn, Cory D.

    2017-01-01

    Proteins localized to mitochondria by a carboxyl-terminal tail anchor (TA) play roles in apoptosis, mitochondrial dynamics, and mitochondrial protein import. To reveal characteristics of TAs that may be important for mitochondrial targeting, we focused our attention upon the TA of the Saccharomyces cerevisiae Fis1 protein. Specifically, we generated a library of Fis1p TA variants fused to the Gal4 transcription factor, then, using next-generation sequencing, revealed which Fis1p TA mutations inhibited membrane insertion and allowed Gal4p activity in the nucleus. Prompted by our global analysis, we subsequently analyzed the ability of individual Fis1p TA mutants to localize to mitochondria. Our findings suggest that the membrane-associated domain of the Fis1p TA may be bipartite in nature, and we encountered evidence that the positively charged patch at the carboxyl terminus of Fis1p is required for both membrane insertion and organelle specificity. Furthermore, lengthening or shortening of the Fis1p TA by up to three amino acids did not inhibit mitochondrial targeting, arguing against a model in which TA length directs insertion of TAs to distinct organelles. Most importantly, positively charged residues were more acceptable at several positions within the membrane-associated domain of the Fis1p TA than negatively charged residues. These findings, emerging from the first high-resolution analysis of an organelle targeting sequence by deep mutational scanning, provide strong, in vivo evidence that lysine and arginine can “snorkel,” or become stably incorporated within a lipid bilayer by placing terminal charges of their side chains at the membrane interface. PMID:28007883

  17. Comparative analysis of phenolic acids in mistletoe plants from various hosts.

    PubMed

    Luczkiewicz, M; Cisowski, W; Kaiser, P; Ochocka, R; Piotrowski, A

    2001-01-01

    Phenolic acids present in mistletoe plants collected from various hosts were analysed with the use of HPLC. The following numbers of compounds were found in the mistletoe plant material gathered from respective hosts: Sorbus aucuparia- 12 compounds; Acer plantanoides--14 compounds: Malus domestica, Pyrus communis and Populus nigra--13 compounds each; Quercus robur--15 compounds. Altogether 21 phenolic acids were chromatographically identified in the tested material. The compounds were either free or combined as esters or glycosides. Comparative chromatography revealed qualitative differences in the investigated compounds between the various plant materials. For example o-coumaric acid was only found in mistletoe hosted by Quercus robur. Digallic acid was only found in the plant material hosted by Acer plantanoides. Qualitative and quantitative composition of mistletoes hosted by Malus domestica and Pyrus communis showed considerable similarities as far as phenolic acids were concerned. Moreover. vanillic acid. absent in all other batches of plant material, seemed to be characteristic of the above mistletoes. Quantitative HPLC analysis demonstrated a considerable content of salicylic acid (39.55 mg%) in mistletoe hosted by Sorbus aucuparia. Apart from the above material, this compound was only present in small quantities in plants hosted by Populus nigra (15.63 mg%) and Quercus robur (2.63 mg%).

  18. Simultaneous determination of shikimic acid, salicylic acid and jasmonic acid in wild and transgenic Nicotiana langsdorffii plants exposed to abiotic stresses.

    PubMed

    Scalabrin, Elisa; Radaelli, Marta; Capodaglio, Gabriele

    2016-06-01

    The presence and relative concentration of phytohormones may be regarded as a good indicator of an organism's physiological state. The integration of the rolC gene from Agrobacterium rhizogenes and of the rat glucocorticoid receptor (gr) in Nicotiana langsdorffii Weinmann plants has shown to determine various physiological and metabolic effects. The analysis of wild and transgenic N. langsdorffii plants, exposed to different abiotic stresses (high temperature, water deficit, and high chromium concentrations) was conducted, in order to investigate the metabolic effects of the inserted genes in response to the applied stresses. The development of a new analytical procedure was necessary, in order to assure the simultaneous determination of analytes and to obtain an adequately low limit of quantification. For the first time, a sensitive HPLC-HRMS quantitative method for the simultaneous determination of salicylic acid, jasmonic acid and shikimic acid was developed and validated. The method was applied to 80 plant samples, permitting the evaluation of plant stress responses and highlighting some metabolic mechanisms. Salicylic, jasmonic and shikimic acids proved to be suitable for the comprehension of plant stress responses. Chemical and heat stresses showed to induce the highest changes in plant hormonal status, differently affecting plant response. The potential of each genetic modification toward the applied stresses was marked and particularly the resistance of the gr modified plants was evidenced. This work provides new information in the study of N. langsdorffii and transgenic organisms, which could be useful for the further application of these transgenes.

  19. Biogeochemistry of metalliferous mine tailings during phytostabilizatio

    NASA Astrophysics Data System (ADS)

    Chorover, J.; Root, R. A.; Hammond, C.; Wang, Y.; Maier, R. M.

    2015-12-01

    In the semi-arid southwest US, legacy mine tailings and the associated metal(loid) contaminants, are prone to wind dispersion and water erosion. Without remediation, tailings can remain barren for decades to centuries, providing a point source of toxic contamination. Successful mitigation of toxins (As, Pb) from fugitive dust is often limited to confinement and stabilization. Capping mine tailings with soil or gravel is an accepted, although expensive, strategy to reduce erosion. Revegetation via assisted direct planting (also known as phytostabilization) has the potential to be a cost-effective and self-sustaining alternative "green-technology" to expensive capping. The impact of phytostabilization, and requisite added organic carbon and irrigation on mechanisms of contaminant mobility is being investigated with concurrent highly-instrumented greenhouse mesocosms and in situ field studies using advanced microbiological tools and synchrotron x-ray based molecular probes. Composted treatments initially neutralized the near surface acid tailings (~2 to ~6.5). However, after 9 mo the mesocosms showed a gradual and eventual decrease back to pH 2. The exception was the root zone of Atriplex lentiformis, which buffered the acidic conditions for 12 months. Rhizosphere microbiota experienced a 5-log increase in the compost-amended compared to control greenhouse mesocosms. Weathering of the primary sulfidic mineral assemblage, indicated by the iron and sulfur speciation, was shown to control the mobility, speciation and bioavailability of both As and Pb via sequestration in (meta)stable neoformed jarosite phases as plumbojarosite and As(V) substituted for sulfate in hydronium jarosite, with important implications for human and environmental health risk management. We conclude that the disequilibrium imposed by phytostabilization results in an increase of heterotrophic biomass that is concurrent with a time series of geochemical transformations, which controls the species

  20. Fact Sheet: Revisions to New Source Performance Standards (NSPS) for Nitric Acid Plants

    EPA Pesticide Factsheets

    This page contains a May 2012 fact sheet with information regarding the New Source Performance Standards (NSPS) for Nitric Acid Plants. This document provides a summary of the information for this NSPS.

  1. Optimized Jasmonic Acid Production by Lasiodiplodia theobromae Reveals Formation of Valuable Plant Secondary Metabolites

    PubMed Central

    Eng, Felipe; Haroth, Sven; Feussner, Kirstin; Meldau, Dorothea; Rekhter, Dmitrij; Ischebeck, Till; Brodhun, Florian

    2016-01-01

    Jasmonic acid is a plant hormone that can be produced by the fungus Lasiodiplodia theobromae via submerged fermentation. From a biotechnological perspective jasmonic acid is a valuable feedstock as its derivatives serve as important ingredients in different cosmetic products and in the future it may be used for pharmaceutical applications. The objective of this work was to improve the production of jasmonic acid by L. theobromae strain 2334. We observed that jasmonic acid formation is dependent on the culture volume. Moreover, cultures grown in medium containing potassium nitrate as nitrogen source produced higher amounts of jasmonic acid than analogous cultures supplemented with ammonium nitrate. When cultivated under optimal conditions for jasmonic acid production, L. theobromae secreted several secondary metabolites known from plants into the medium. Among those we found 3-oxo-2-(pent-2-enyl)-cyclopentane-1-butanoic acid (OPC-4) and hydroxy-jasmonic acid derivatives, respectively, suggesting that fungal jasmonate metabolism may involve similar reaction steps as that of plants. To characterize fungal growth and jasmonic acid-formation, we established a mathematical model describing both processes. This model may form the basis of industrial upscaling attempts. Importantly, it showed that jasmonic acid-formation is not associated to fungal growth. Therefore, this finding suggests that jasmonic acid, despite its enormous amount being produced upon fungal development, serves merely as secondary metabolite. PMID:27907207

  2. The effect of rumen adaptation to oxalic acid on selection of oxalic-acid-rich plants by goats.

    PubMed

    Duncan, A J; Frutos, P; Young, S A

    2000-01-01

    Rumen microbial degradation is an important route for detoxification of secondary plant compounds encountered in the diets of free-grazing ruminants. Exposure to diets containing particular secondary plant compounds can lead to increased rates of secondary compound degradation in the rumen. An experiment was conducted to determine whether rumen adaptation to oxalic acid would influence the diet selection of goats offered choices between plant species differing in their oxalic acid content. Twelve adult female goats were divided into two groups of six animals each. One group received a daily oral dose, in gelatin capsules, of 0.6 mmol oxalic acid/kg live weight per d throughout the experiment while the other group received placebos consisting of empty gelatin capsules. After an adaptation period of 8 d, the animals were allowed to graze a mixture of spinach (rich in oxalic acid) and cabbage (low in oxalic acid) for 7 h/d on two consecutive days per week during four consecutive 1-week periods. Intervening days were spent on grass pasture. Diet composition and intake were measured using cuticular wax n-alkanes as internal markers. Results showed that adapted goats included a higher proportion of spinach in their diet (P < 0.05) although absolute intakes of spinach were the same for the two groups. Goats in the oxalic-acid-adapted group consumed less cabbage than control animals (P < 0.05) suggesting that adaptation to oxalic acid at the rumen level may have interfered with detoxification of cabbage-derived secondary plant compounds. Voluntary intake increased progressively through the four experimental periods (P < 0.001) with a tendency for higher intakes among control than among adapted animals (P < 0.1). The experiment demonstrates how differences in the rate of degradation of secondary plant compounds may influence diet selection in ruminants.

  3. Reduction of divinyl ether-containing polyunsaturated fatty acids in transgenic potato plants.

    PubMed

    Eschen-Lippold, Lennart; Rothe, Grit; Stumpe, Michael; Göbel, Cornelia; Feussner, Ivo; Rosahl, Sabine

    2007-03-01

    Oxygenated polyunsaturated fatty acids synthesized via the lipoxygenase pathway play a role in plant responses to pathogen attack. In solanaceous plants, the preferential stimulation of the 9-lipoxygenase pathway in response to pathogen infection leads to the formation of the divinyl ether-containing polyunsaturated fatty acids colneleic and colnelenic acid, as well as hydroxy and trihydroxy polyunsaturated fatty acids. To functionally assess the role of divinyl ethers, transgenic potato plants were generated which express an RNA interference construct directed against the pathogen-inducible 9-divinyl ether synthase. Efficient reduction of 9-divinyl ether synthase transcript accumulation correlated with reduced levels of colneleic and colnelenic acid. However, in response to infection with virulent Phytophthora infestans, the causal agent of late blight disease, no significant differences in pathogen biomass could be detected suggesting that the levels of antimicrobial divinyl ethers are not critical for defense against Phytophthora infestans in a compatible interaction.

  4. First record of soybean as a host plant of a subspecies of the eastern tailed-blue, Cupido comyntas comyntas (Lepidoptera: Lycaenidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multitude of invertebrate herbivores feeds upon soybean in North America, with many species considered to be pests of soybean in northern U.S. production areas. Cupido comyntas, the eastern tailed-blue (Lepidoptera: Lycaenidae), is a legume-feeding caterpillar native to North America. One of its...

  5. Cloning and functional expression of the first plant fatty acid elongase specific for Delta(6)-polyunsaturated fatty acids.

    PubMed

    Zank, T K; Zähringer, U; Lerchl, J; Heinz, E

    2000-12-01

    In order to elucidate the biosynthesis of long-chain polyunsaturated fatty acids (PUFAs) in plants we searched for a cDNA encoding a Delta(6)-specific PUFA elongase from Physcomitrella patens, which is known to contain high proportions of arachidonic acid (20:4 Delta(5,8,11,14)). An EST clone from P. patens was identified by its low homology to the yeast gene ELO1, which is required for the elongation of medium-chain fatty acids. We functionally characterized this cDNA by heterologous expression in Saccharomyces cerevisiae grown in the presence of several fatty acids. Analysis of the fatty acid profile of the transgenic yeast revealed that the cDNA encodes a protein that leads to the elongation of the C(18) Delta(6)-polyunsaturated fatty acids gamma-linolenic acid (18:3 Delta(6,9,12)) and stearidonic acid (18:4 Delta(6,9,12,15)), which were recovered to 45-51% as their elongation products. In contrast, linoleic and alpha-linolenic acids were hardly elongated and we could not measure any elongation of saturated and mono-unsaturated fatty acids (including 18:1 Delta(6)), indicating that the elongase is highly specific for the polyunsaturated nature of the fatty acid acting as substrate.

  6. Natural toxins that affect plant amino acid metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A diverse range of natural compounds interfere with the synthesis and other aspects of amino acid metabolism. Some are amino acid analogues, but most are not. This review covers a number of specific natural phytotoxic compounds by molecular target site. Inhibition of glutamine synthetase is of part...

  7. Controlling plant architecture by manipulation of gibberellic acid signalling in petunia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gibberellic acid (GA), a plant hormone, regulates many crucial growth and developmental processes, including seed germination, leaf expansion, induction of flowering and stem elongation. A common problem in the production of ornamental potted plants is undesirably tall growth, so inhibitors of gibbe...

  8. Phosphoric acid fuel cell power plant system performance model and computer program

    NASA Technical Reports Server (NTRS)

    Alkasab, K. A.; Lu, C. Y.

    1984-01-01

    A FORTRAN computer program was developed for analyzing the performance of phosphoric acid fuel cell power plant systems. Energy mass and electrochemical analysis in the reformer, the shaft converters, the heat exchangers, and the fuel cell stack were combined to develop a mathematical model for the power plant for both atmospheric and pressurized conditions, and for several commercial fuels.

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

    SciTech Connect

    Huang, J.W.; Blaylock, M.J.; Kapulnik, Y.; Ensley, B.D.

    1998-07-01

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

  10. Enviromental Effects on Oleic Acid in Soybean Seed Oil of Plant Introductions with Elevated Oleic Concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean [Glycine max (L.) Merr.] oil with oleic acid content >500 g per kg is desirable for a broader role in food and industrial uses. Seed oil in commercially grown soybean genotypes averages about 230 g per kg oleic acid (18:1). Some maturity group (MG) II to V plant introductions (PIs) have el...

  11. EFFECT OF INDOLE-3-ACETIC ACID, KINETIN, AND ETHYLENEDIAMINETETRAACETIC ACID ON PLANT GROWTH AND UPTAKE AND TRANSLOCATION OF LEAD, MICRONUTRIENTS, AND MACRONUTRIENTS IN ALFALFA PLANTS.

    PubMed

    López, Martha Laura; Peralta-Videa, José R; Parsons, Jason G; Gardea-Torresdey, Jorge L; Duarte-Gardea, Maria

    2009-02-01

    Alfalfa plants germinated and grown for 15 d in soil containing 80 mg Pb kg(-1) were treated with ethylenediaminetetraacetic acid (EDTA) at 0.8 mM and indole-3-acetic acid-kinetin (IAA-KN) at 100 μM. Fifteen days after the treatment application, the concentration of lead (Pb), macronutrients, and micronutrients was determined using inductively coupled plasma/optical emission spectroscopy. The chlorophyll content and plant growth were also measured. Roots of plants exposed to Pb alone, Pb-EDTA, and Pb-EDTA-IAA-KN had 160, 140, and 150 mg Pb kg(-1) DW, respectively. Pb was not detected in the stems of plants exposed to Pb alone; however, stems of plants treated with EDTA and EDTA-IAA-KN had 78 and 142 mg Pb kg(-1) DW, respectively. While the Pb concentration in leaves of plants treated with EDTA and EDTA-IAA-KN was 92 and 127 mg kg(-1) DW, respectively. In addition, EDTA and EDTA-IAA-KN significantly increased the translocation of zinc and manganese to leaves. The x-ray absorption spectroscopic studies demonstrated that Pb(II) was transported from roots to leaves without a change in the oxidation state.

  12. Beta-aminobutyric acid priming of plant defense: the role of ABA and other hormones.

    PubMed

    Baccelli, Ivan; Mauch-Mani, Brigitte

    2016-08-01

    Plants are exposed to recurring biotic and abiotic stresses that can, in extreme situations, lead to substantial yield losses. With the changing environment, the stress pressure is likely to increase and sustainable measures to alleviate the effect on our crops are sought. Priming plants for better stress resistance is one of the sustainable possibilities to reach this goal. Here, we report on the effects of beta-aminobutyric acid, a priming agent with an exceptionally wide range of action and describe its way of preparing plants to defend themselves against various attacks, among others through the modulation of their hormonal defense signaling, and highlight the special role of abscisic acid in this process.

  13. Pb uptake and toxicity to Iris halophila tested on Pb mine tailing materials.

    PubMed

    Han, Yulin; Zhang, Lili; Yang, Yongheng; Yuan, Haiyan; Zhao, Jiuzhou; Gu, Jiguang; Huang, Suzhen

    2016-07-01

    Pb tolerant mechanisms, plant physiological response and Pb sub-cellular localization in the root cells of Iris halophila were studied in sand culture and the Pb mine tailings. Results showed that the activities of superoxide dismutase (SOD) and peroxidase (POD) in the underground parts and the activity of catalase (CAT) in the aboveground and underground parts increased as Pb level was enhanced. Glutathione (GSH) and ascorbic acid (AsA) contents increased by Pb treatments. Pb deposits were found in the middle cell walls or along the inner side of epibiotic protoplasm of some cells which accumulated a large quantity of Pb and died. The dry weights (DWs) of aboveground parts under all Pb tailings treatments decreased insignificantly, while the DW of the underground parts growing in the pure Pb tailings decreased significantly. Pb, Cu, Cd, and Zn contents increased significantly as the levels of Pb tailings were enhanced and Pb contents in the aboveground and underground parts reached 64.75 and 751.75 μg/g DW, respectively, at pure Pb tailings treatment. The results indicated that I. halophila is a promising plant in the phytoremediation of Pb contaminated environment. Some antioxidant enzymes, antioxidants and compartmentalization of Pb were played major roles in Pb tolerance of I. halophila.

  14. The dynamics of embolism refilling in abscisic acid (ABA)-deficient tomato plants.

    PubMed

    Secchi, Francesca; Perrone, Irene; Chitarra, Walter; Zwieniecka, Anna K; Lovisolo, Claudio; Zwieniecki, Maciej A

    2012-12-24

    Plants are in danger of embolism formation in xylem vessels when the balance between water transport capacity and transpirational demand is compromised. To maintain this delicate balance, plants must regulate the rate of transpiration and, if necessary, restore water transport in embolized vessels. Abscisic acid (ABA) is the dominant long-distance signal responsible for plant response to stress, and it is possible that it plays a role in the embolism/refilling cycle. To test this idea, a temporal analysis of embolism and refilling dynamics, transpiration rate and starch content was performed on ABA-deficient mutant tomato plants. ABA-deficient mutants were more vulnerable to embolism formation than wild-type plants, and application of exogenous ABA had no effect on vulnerability. However, mutant plants treated with exogenous ABA had lower stomatal conductance and reduced starch content in the xylem parenchyma cells. The lower starch content could have an indirect effect on the plant's refilling activity. The results confirm that plants with high starch content (moderately stressed mutant plants) were more likely to recover from loss of water transport capacity than plants with low starch content (mutant plants with application of exogenous ABA) or plants experiencing severe water stress. This study demonstrates that ABA most likely does not play any direct role in embolism refilling, but through the modulation of carbohydrate content, it could influence the plant's capacity for refilling.

  15. D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants)

    SciTech Connect

    Loewus, F.A. . Inst. of Biological Chemistry); Seib, P.A. . Dept. of Grain Science and Industry)

    1990-01-01

    Sclerotinia sclerotiorum contains D-erythroascorbic acid (EAA) and a closely related reducing acid, possibly the open-chain form of EAA. The organism cleaves one of these products or possibly both to yield OA and D-glyceric acid. The OA is rapidly secreted into the medium. An analogy can be made between AA-linked OA biosynthesis in higher plants and EAA-linked OA biosynthesis in fungi as exemplified by S. sclerotiorum.

  16. Fermentation of aqueous plant seed extracts by lactic acid bacteria

    SciTech Connect

    Schafner, D.W.; Beuchat, R.L.

    1986-05-01

    The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

  17. Phenolic acids act as signaling molecules in plant-microbe symbioses

    PubMed Central

    Mandal, Santi M; Chakraborty, Dipjyoti

    2010-01-01

    Phenolic acids are the main polyphenols made by plants. These compounds have diverse functions and are immensely important in plant-microbe interactions/symbiosis. Phenolic compounds act as signaling molecules in the initiation of legumerhizobia symbioses, establishment of arbuscular mycorrhizal symbioses and can act as agents in plant defense. Flavonoids are a diverse class of polyphenolic compounds that have received considerable attention as signaling molecules involved in plant-microbe interactions compared to the more widely distributed, simple phenolic acids; hydroxybenzoic and hydroxycinnamic acids, which are both derived from the general phenylpropanoid pathway. This review describes the well-known roles attributed to phenolic compounds as nod gene inducers of legume-rhizobia symbioses, their roles in induction of the GmGin1 gene in fungus for establishment of arbuscular mycorrhizal symbiosis, their roles in inducing vir gene expression in Agrobacterium, and their roles as defense molecules operating against soil borne pathogens that could have great implications for rhizospheric microbial ecology. Amongst plant phenolics we have a lack of knowledge concerning the roles of phenolic acids as signaling molecules beyond the relatively well-defined roles of flavonoids. This may be addressed through the use of plant mutants defective in phenolic acids biosynthesis or knock down target genes in future investigations. PMID:20400851

  18. Electrodialytic remediation of copper mine tailings.

    PubMed

    Hansen, Henrik K; Rojo, Adrián; Ottosen, Lisbeth M

    2005-01-31

    Mining activities in Chile have generated large amounts of solid waste, which have been deposited in mine tailing impoundments. These impoundments cause concern to the communities due to dam failures or natural leaching to groundwater and rivers. This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper from watery tailing if the potential gradient was higher than 2 V/cm during 21 days. With addition of sulphuric acid, the process was enhanced because the pH decreased to around 4, and the copper by this reason was released in the solution. Furthermore, with acidic tailing the potential gradient was less than 2 V/cm. The maximum copper removal reached in the anode side was 53% with addition of sulphuric acid in 21 days experiment at 20 V using approximately 1.8 kg mine tailing on dry basis. In addition, experiments with acidic tailing show that the copper removal is proportional with time.

  19. Alteration of plant physiology by glyphosate and its by-product aminomethylphosphonic acid: an overview.

    PubMed

    Gomes, Marcelo P; Smedbol, Elise; Chalifour, Annie; Hénault-Ethier, Louise; Labrecque, Michel; Lepage, Laurent; Lucotte, Marc; Juneau, Philippe

    2014-09-01

    It is generally claimed that glyphosate kills undesired plants by affecting the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme, disturbing the shikimate pathway. However, the mechanisms leading to plant death may also be related to secondary or indirect effects of glyphosate on plant physiology. Moreover, some plants can metabolize glyphosate to aminomethylphosphonic acid (AMPA) or be exposed to AMPA from different environmental matrices. AMPA is a recognized phytotoxin, and its co-occurrence with glyphosate could modify the effects of glyphosate on plant physiology. The present review provides an overall picture of alterations of plant physiology caused by environmental exposure to glyphosate and its metabolite AMPA, and summarizes their effects on several physiological processes. It particularly focuses on photosynthesis, from photochemical events to C assimilation and translocation, as well as oxidative stress. The effects of glyphosate and AMPA on several plant physiological processes have been linked, with the aim of better understanding their phytotoxicity and glyphosate herbicidal effects.

  20. Nematodes Associated with Plants from Naturally Acidic Wetlands Soil

    PubMed Central

    Cox, Robert John; Smart, Grover C.

    1994-01-01

    Four plants, Cyperus ochraceus, Eriocaulon compressum, Lythrum alatum, and Xyris jupicai, growing along the shoreline of an oligotrophic lake in north central Florida were sampled for nematodes. The nematodes recovered were placed in four trophic groups: bacterivores, herbivores, omnivores, and predators. When the nematodes on all plants were considered, 27% were bacterivores, 23% were herbivores, 7% were omnivores, and 43% were predators. Tripyla was the dominant predator and the dominant genus of all nematodes, and Malenchus was the dominant herbivore. Dominance was not clearly pronounced in the other trophic groups. PMID:19279927

  1. Hanford waste vitrification plant hydrogen generation study: Preliminary evaluation of alternatives to formic acid

    SciTech Connect

    King, R.B.; Bhattacharyya, N.K.; Kumar, V.

    1996-02-01

    Oxalic, glyoxylic, glycolic, malonic, pyruvic, lactic, levulinic, and citric acids as well as glycine have been evaluated as possible substitutes for formic acid in the preparation of feed for the Hanford waste vitrification plant using a non-radioactive feed stimulant UGA-12M1 containing substantial amounts of aluminum and iron oxides as well as nitrate and nitrite at 90C in the presence of hydrated rhodium trichloride. Unlike formic acid none of these carboxylic acids liberate hydrogen under these conditions and only malonic and citric acids form ammonia. Glyoxylic, glycolic, malonic, pyruvic, lactic, levulinic, and citric acids all appear to have significant reducing properties under the reaction conditions of interest as indicated by the observation of appreciable amounts of N{sub 2}O as a reduction product of,nitrite or, less likely, nitrate at 90C. Glyoxylic, pyruvic, and malonic acids all appear to be unstable towards decarboxylation at 90C in the presence of Al(OH){sub 3}. Among the carboxylic acids investigated in this study the {alpha}-hydroxycarboxylic acids glycolic and lactic acids appear to be the most interesting potential substitutes for formic acid in the feed preparation for the vitrification plant because of their failure to produce hydrogen or ammonia or to undergo decarboxylation under the reaction conditions although they exhibit some reducing properties in feed stimulant experiments.

  2. Pipecolic Acid Orchestrates Plant Systemic Acquired Resistance and Defense Priming via Salicylic Acid-Dependent and -Independent Pathways

    PubMed Central

    Bernsdorff, Friederike; Döring, Anne-Christin; Gruner, Katrin; Schuck, Stefan; Bräutigam, Andrea; Zeier, Jürgen

    2016-01-01

    We investigated the relationships of the two immune-regulatory plant metabolites, salicylic acid (SA) and pipecolic acid (Pip), in the establishment of plant systemic acquired resistance (SAR), SAR-associated defense priming, and basal immunity. Using SA-deficient sid2, Pip-deficient ald1, and sid2 ald1 plants deficient in both SA and Pip, we show that SA and Pip act both independently from each other and synergistically in Arabidopsis thaliana basal immunity to Pseudomonas syringae. Transcriptome analyses reveal that SAR establishment in Arabidopsis is characterized by a strong transcriptional response systemically induced in the foliage that prepares plants for future pathogen attack by preactivating multiple stages of defense signaling and that SA accumulation upon SAR activation leads to the downregulation of photosynthesis and attenuated jasmonate responses systemically within the plant. Whereas systemic Pip elevations are indispensable for SAR and necessary for virtually the whole transcriptional SAR response, a moderate but significant SA-independent component of SAR activation and SAR gene expression is revealed. During SAR, Pip orchestrates SA-dependent and SA-independent priming of pathogen responses in a FLAVIN-DEPENDENT-MONOOXYGENASE1 (FMO1)-dependent manner. We conclude that a Pip/FMO1 signaling module acts as an indispensable switch for the activation of SAR and associated defense priming events and that SA amplifies Pip-triggered responses to different degrees in the distal tissue of SAR-activated plants. PMID:26672068

  3. [Process and mechanism of plants in overcoming acid soil aluminum stress].

    PubMed

    Zhao, Tian-Long; Xie, Guang-Ning; Zhang, Xiao-Xia; Qiu, Lin-Quan; Wang, Na; Zhang, Su-Zhi

    2013-10-01

    Aluminum (Al) stress is one of the most important factors affecting the plant growth on acid soil. Currently, global soil acidification further intensifies the Al stress. Plants can detoxify Al via the chelation of ionic Al and organic acids to store the ionic Al in vacuoles and extrude it from roots. The Al extrusion is mainly performed by the membrane-localized anion channel proteins Al(3+)-activated malate transporter (ALMT) and multi-drug and toxin extrusion (MATE). The genes encoding ABC transporter and zinc-finger protein conferred plant Al tolerance have also been found. The identification of these Al-resistant genes makes it possible to increase the Al resistance of crop plants and enhance their production by the biological methods such as gene transformation and mark-associated breeding. The key problems needed to be solved and the possible directions in the researches of plant Al stress resistance were proposed.

  4. Very long chain fatty acid and lipid signaling in the response of plants to pathogens

    PubMed Central

    Raffaele, Sylvain; Leger, Amandine

    2009-01-01

    Recent findings indicate that lipid signaling is essential for plant resistance to pathogens. Besides oxylipins and unsaturated fatty acids known to play important signaling functions during plant-pathogen interactions, the very long chain fatty acid (VLCFA) biosynthesis pathway has been recently associated to plant defense through different aspects. VLCFAs are indeed required for the biosynthesis of the plant cuticle and the generation of sphingolipids. Elucidation of the roles of these lipids in biotic stress responses is the result of the use of genetic approaches together with the identification of the genes/proteins involved in their biosynthesis. This review focuses on recent observations which revealed the complex function of the cuticle and cuticle-derived signals, and the key role of sphingolipids as bioactive molecules involved in signal transduction and cell death regulation during plant-pathogen interactions. PMID:19649180

  5. A Fluorescent Assay for Plant Caffeic Acid O-methyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have developed a facile, sensitive and continuous assay to measure the activities of plant COMTs using s-adenosyl homocysteine hydrolase as a coupling enzyme and and adeonsine a thiol-specific fluor, Thioglo1, as the detecting reagent. This assay was validated using recombinant sorghum COMT (BMR-...

  6. Phosphate Solubilizing Bacillus megaterium mj1212 Regulates Endogenous Plant Carbohydrates and Amino Acids Contents to Promote Mustard Plant Growth.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Lee, Ko-Eun; Kim, Jin-Ho

    2014-12-01

    The current study was conducted to explore the potential of a phosphate solubilizing soil bacterium, Bacillus megaterium mj1212 for enhancing the growth of mustard plants. The newly isolated bacterial strain mj1212 was identified as B. megaterium using phylogenetic analysis and, its phosphate solubilization ability was shown by the clear zone formation on National Botanical Research Institute's Phosphate medium. Moreover, the phosphate solubilization ability of B. megaterium mj1212 was enhanced by optimal culture conditions at pH 7.0 and 35 °C which might be due to the presence of malic and quinic acid in the culture medium. The beneficial effect of B. megaterium mj1212 in mustard plants was determined by an increasing shoot length, root length and fresh weight of plants. In the biochemical analysis revealed that chlorophyll, sucrose, glucose, fructose and amino acids (Asp, Thr, Ser, Glu, Gly, Ala, Cys, Val, Met, Ilu, Leu, Tyr, Phe, Lys, His, Arg and Pro) were higher in B. megaterium mj1212 treated plants, when compared to their control. The result of present study suggests that B. megaterium mj1212 treatment could be act as phosphate biofertilizer to improve the plant growth.

  7. A Binary Host Plant Volatile Lure Combined With Acetic Acid to Monitor Codling Moth (Lepidoptera: Tortricidae).

    PubMed

    Knight, A L; Basoalto, E; Katalin, J; El-Sayed, A M

    2015-10-01

    Field studies were conducted in the United States, Hungary, and New Zealand to evaluate the effectiveness of septa lures loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E)-4,8-dimethyl-1,3,7-nonatriene (nonatriene) alone and in combination with an acetic acid co-lure for both sexes of codling moth, Cydia pomonella (L.). Additional studies were conducted to evaluate these host plant volatiles and acetic acid in combination with the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone). Traps baited with pear ester/nonatriene + acetic acid placed within orchards treated either with codlemone dispensers or left untreated caught significantly more males, females, and total moths than similar traps baited with pear ester + acetic acid in some assays. Similarly, traps baited with codlemone/pear ester/nonatriene + acetic acid caught significantly greater numbers of moths than traps with codlemone/pear ester + acetic acid lures in some assays in orchards treated with combinational dispensers (dispensers loaded with codlemone/pear ester). These data suggest that monitoring of codling moth can be marginally improved in orchards under variable management plans using a binary host plant volatile lure in combination with codlemone and acetic acid. These results are likely to be most significant in orchards treated with combinational dispensers. Significant increases in the catch of female codling moths in traps with the binary host plant volatile blend plus acetic acid should be useful in developing more effective mass trapping strategies.

  8. Jasmonic acid enhances plant cyanogenesis and resistance to herbivory in lima bean.

    PubMed

    Kautz, Stefanie; Trisel, Julie A; Ballhorn, Daniel J

    2014-12-01

    Jasmonic acid (JA) is a natural plant hormone ubiquitously distributed in plants and centrally involved in the induction of direct and indirect plant defenses. Defenses up-regulated by this hormone include trichomes--a direct, mechanical defense--and alkaloids--a direct chemical defense--as well as two indirect chemical defenses: volatile organic compounds (VOCs) and extrafloral nectar (EFN). Plant cyanogenesis--the release of toxic hydrogen cyanide (HCN) from preformed cyanogenic precursors in fruits, leaves, and seeds of many plants--is recognized as a direct, constitutive plant defensive trait, and is among the most widely distributed of all direct chemical plant defenses. The cyanogenic system in plants is composed of three parameters: The cyanogenic potential (HCNp; concentration of cyanogenic precursors), β-glucosidase activity, and cyanogenic capacity (HCNc; release of gaseous hydrogen cyanide). Here, we demonstrated that experimental application of aqueous solutions of JA ranging from 0.001 to 1.0 mmol L(-1), as well as insect herbivory significantly enhanced HCNc via the induction of β-glucosidase activity in wild lima bean (Phaseolus lunatus L.). In choice feeding trials with JA induced and damaged leaves, adult Mexican bean beetles--natural herbivores of lima bean--rejected leaves with enhanced β-glucosidase activity and HCNc. Our findings suggest that jasmonic acid plays a critical role in regulating activity of β-glucosidases, which determines the rate of cyanogenesis, and thus mediates direct plant defense against herbivores.

  9. Bioengineered Plants Can Be a Useful Source of Omega-3 Fatty Acids.

    PubMed

    Amjad Khan, Waleed; Chun-Mei, Hu; Khan, Nadeem; Iqbal, Amjad; Lyu, Shan-Wu; Shah, Farooq

    2017-01-01

    Omega-3 fatty acids have proven to be very essential for human health due to their multiple health benefits. These essential fatty acids (EFAs) need to be uptaken through diet because they are unable to be produced by the human body. These are important for skin and hair growth as well as for proper visual, neural, and reproductive functions of the body. These fatty acids are proven to be extremely vital for normal tissue development during pregnancy and infancy. Omega-3 fatty acids can be obtained mainly from two dietary sources: marine and plant oils. Eicosapentaenoic acid (EPA; C20:5 n-3) and docosahexaenoic acid (DHA; C22:6 n-3) are the primary marine-derived omega-3 fatty acids. Marine fishes are high in omega-3 fatty acids, yet high consumption of those fishes will cause a shortage of fish stocks existing naturally in the oceans. An alternative source to achieve the recommended daily intake of EFAs is the demand of today. In this review article, an attempt has, therefore, been made to discuss the importance of omega-3 fatty acids and the recent developments in order to produce these fatty acids by the genetic modifications of the plants.

  10. Bioengineered Plants Can Be a Useful Source of Omega-3 Fatty Acids

    PubMed Central

    Lyu, Shan-Wu

    2017-01-01

    Omega-3 fatty acids have proven to be very essential for human health due to their multiple health benefits. These essential fatty acids (EFAs) need to be uptaken through diet because they are unable to be produced by the human body. These are important for skin and hair growth as well as for proper visual, neural, and reproductive functions of the body. These fatty acids are proven to be extremely vital for normal tissue development during pregnancy and infancy. Omega-3 fatty acids can be obtained mainly from two dietary sources: marine and plant oils. Eicosapentaenoic acid (EPA; C20:5 n-3) and docosahexaenoic acid (DHA; C22:6 n-3) are the primary marine-derived omega-3 fatty acids. Marine fishes are high in omega-3 fatty acids, yet high consumption of those fishes will cause a shortage of fish stocks existing naturally in the oceans. An alternative source to achieve the recommended daily intake of EFAs is the demand of today. In this review article, an attempt has, therefore, been made to discuss the importance of omega-3 fatty acids and the recent developments in order to produce these fatty acids by the genetic modifications of the plants. PMID:28316988

  11. Effects of root-zone acidity on utilization of nitrate and ammonium in tobacco plants

    NASA Technical Reports Server (NTRS)

    Henry, L. T.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1989-01-01

    Tobacco (Nicotiana tabacum L., cv. 'Coker 319') plants were grown for 28 days in flowing nutrient culture containing either 1.0 mM NO3- or 1.0 mM NH4+ as the nitrogen source in a complete nutrient solution. Acidities of the solutions were controlled at pH 6.0 or 4.0 for each nitrogen source. Plants were sampled at intervals of 6 to 8 days for determination of dry matter and nitrogen accumulation. Specific rates of NO3- or NH4+ uptake (rate of uptake per unit root mass) were calculated from these data. Net photosynthetic rates per unit leaf area were measured on attached leaves by infrared gas analysis. When NO3- [correction of NO-] was the sole nitrogen source, root growth and nitrogen uptake rate were unaffected by pH of the solution, and photosynthetic activity of leaves and accumulation of dry matter and nitrogen in the whole plant were similar. When NH4+ was the nitrogen source, photosynthetic rate of leaves and accumulation of dry matter and nitrogen in the whole plant were not statistically different from NO3(-) -fed plants when acidity of the solution was controlled at pH 6.0. When acidity for NH4(+) -fed plants was increased to pH 4.0, however, specific rate of NH4+ uptake decreased by about 50% within the first 6 days of treatment. The effect of acidity on root function was associated with a decreased rate of accumulation of nitrogen in shoots that was accompanied by a rapid cessation of leaf development between days 6 and 13. The decline in leaf growth rate of NH4(+) -fed plants at pH 4.0 was followed by reductions in photosynthetic rate per unit leaf area. These responses of NH4(+) -fed plants to increased root-zone acidity are characteristic of the sequence of responses that occur during onset of nitrogen stress.

  12. Stepwise engineering to produce high yields of very long-chain polyunsaturated fatty acids in plants.

    PubMed

    Wu, Guohai; Truksa, Martin; Datla, Nagamani; Vrinten, Patricia; Bauer, Joerg; Zank, Thorsten; Cirpus, Petra; Heinz, Ernst; Qiu, Xiao

    2005-08-01

    Very long chain polyunsaturated fatty acids (VLCPUFAs) such as arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are valuable commodities that provide important human health benefits. We report the transgenic production of significant amounts of AA and EPA in Brassica juncea seeds via a stepwise metabolic engineering strategy. Using a series of transformations with increasing numbers of transgenes, we demonstrate the incremental production of VLCPUFAs, achieving AA levels of up to 25% and EPA levels of up to 15% of total seed fatty acids. Both fatty acids were almost exclusively found in triacylglycerols, with AA located preferentially at sn-2 and sn-3 positions and EPA distributed almost equally at all three positions. Moreover, we reconstituted the DHA biosynthetic pathway in plant seeds, demonstrating the practical feasibility of large-scale production of this important omega-3 fatty acid in oilseed crops.

  13. The Dynamics of Embolism Refilling in Abscisic Acid (ABA)-Deficient Tomato Plants

    PubMed Central

    Secchi, Francesca; Perrone, Irene; Chitarra, Walter; Zwieniecka, Anna K.; Lovisolo, Claudio; Zwieniecki, Maciej A.

    2013-01-01

    Plants are in danger of embolism formation in xylem vessels when the balance between water transport capacity and transpirational demand is compromised. To maintain this delicate balance, plants must regulate the rate of transpiration and, if necessary, restore water transport in embolized vessels. Abscisic acid (ABA) is the dominant long-distance signal responsible for plant response to stress, and it is possible that it plays a role in the embolism/refilling cycle. To test this idea, a temporal analysis of embolism and refilling dynamics, transpiration rate and starch content was performed on ABA-deficient mutant tomato plants. ABA-deficient mutants were more vulnerable to embolism formation than wild-type plants, and application of exogenous ABA had no effect on vulnerability. However, mutant plants treated with exogenous ABA had lower stomatal conductance and reduced starch content in the xylem parenchyma cells. The lower starch content could have an indirect effect on the plant’s refilling activity. The results confirm that plants with high starch content (moderately stressed mutant plants) were more likely to recover from loss of water transport capacity than plants with low starch content (mutant plants with application of exogenous ABA) or plants experiencing severe water stress. This study demonstrates that ABA most likely does not play any direct role in embolism refilling, but through the modulation of carbohydrate content, it could influence the plant’s capacity for refilling. PMID:23263667

  14. Abscisic acid substantially inhibits senescence of cucumber plants (Cucumis sativus) grown under low nitrogen conditions.

    PubMed

    Oka, Mariko; Shimoda, Yousuke; Sato, Naoko; Inoue, Junya; Yamazaki, Teru; Shimomura, Norihiro; Fujiyama, Hideyasu

    2012-05-15

    Low nitrogen (N) availability such as that found in both dry land and tropical regions limits plant growth and development. The relationship between the level of abscisic acid (ABA) in a plant and its growth under low-N conditions was investigated. The level of ABA in cucumber (Cucumis sativus) plants under low-N conditions was significantly higher at 10 and 20 d after transplantation compared with that under sufficient-N conditions. Chlorophyll was preserved in the aerial parts of cucumber plants grown under low-N conditions in the presence of ABA, while there was no significant difference between control plants and ABA-applied plants under sufficient-N conditions. ABA suppressed the reduction of chlorophyll biosynthesis under low-N conditions but not under sufficient-N conditions. On the other hand, ABA decreased the expression of the chlorophyll degradation gene in older cucumber plants grown under both conditions. In addition, transcript and protein levels of a gene encoding a chlorophyll a/b binding protein were positively correlated with ABA concentration under low-N conditions. The chloroplasts in control plants were round, and the stack of thylakoid membranes was reduced compared with that of plants treated with ABA 10(-5) M. These results strongly suggest that ABA is accumulated in cucumber plants grown under low-N conditions and that accumulated ABA promotes chlorophyll biosynthesis and inhibits its degradation in those plants.

  15. Survey of boric acid corrosion of carbon steel components in nuclear plants

    SciTech Connect

    Czajkowski, C.J. )

    1990-06-01

    A review has been performed on license responses (50) to Generic Letter 88-05. Joint Brookhaven National Laboratory (BNL) and USNRC audits were performed on a series (10) of affected licensees. The plant audits showed a considerable variance in the mode and quality of boric acid corrosion prevention programs between utilities. The degree of importance of a boric acid corrosion control program also varied considerably between plants. In the plants where a reasonably high priority was given to the problem, the leaks were identified and corrective actions taken in a timely manner. Each of the plants audited had a boric acid corrosion prevention program in effect at the time of the plant visit. In many cases, the program consisted of modifications to existing leakage control procedures. Training of inspectors was accomplished by all audited licensees. In general, the inspectors were certified to the VT-2 qualification and in some instances to the EPRI visual inspection certifications. In general, all of the sites audited kept their plants relatively clean (with one exception). The majority of plants either cleaned their spills in short order and repaired the leaks or found methods of draining or containment of the liquids. All of the audited licensees satisfactorily addressed the four specified requirements of Generic Letter 88-05. 22 refs., 3 figs., 2 tabs.

  16. Effects of a mixture of fatty acids from sugar cane (Saccharum officinarum L.) wax oil in two models of inflammation: zymosan-induced arthritis and mice tail test of psoriasis.

    PubMed

    Ledón, N; Casacó, A; Remirez, D; González, A; Cruz, J; González, R; Capote, A; Tolón, Z; Rojas, E; Rodríguez, V J; Merino, N; Rodríguez, S; Ancheta, O; Cano, M C

    2007-10-01

    A mixture of fatty acids obtained from sugar cane (Saccharum officinarum L.) wax oil (FAM), in which the main constituents are palmitic, oleic, linoleic, and linolenic acids, was evaluated in two models of inflammation: zymosan-induced arthritis and in the tail test for psoriasis, both on mice. In the first model, FAM significantly reduced zymozan-induced increase of beta glucuronidase (DE(50) 90+/-7 mg/kg). Histopathological studies showed inhibition in cellular infiltration and reduction of synovial hyperplasia and synovitis, whereas in the second test, histopathological and ultrastructural studies showed that topical application of FAM induced orthokeratosis with the presence of keratohyalin granules in the previously parakeratotic adult mouse tail, and without effects on epidermal thickness. The ED(50) of FAM in this model was 155+/-10 mg. The results of our studies showed that topical application of FAM exerts an important anti-inflammatory activity in both tests without evidence of irritant effects. The anti-inflamatory effects exerted by FAM may be due to its inhibitory effects on arachidonic acid metabolism. To our knowledge, this is the first report on the anti-inflammatory effect of sugar cane by-products in experimental models of arthritis and psoriasis.

  17. Colonization by Phloem-Feeding Herbivore Overrides Effects of Plant Virus on Amino Acid Composition in Phloem of Chili Plants.

    PubMed

    Ángeles-López, Yesenia Ithaí; Rivera-Bustamante, Rafael F; Heil, Martin

    2016-10-01

    The 'adaptive host manipulation' hypothesis predicts that parasites can enhance their transmission rates via manipulation of their host's phenotype. For example, many plant pathogens alter the nutritional quality of their host for herbivores that serve as their vectors. However, herbivores, including non-vectors, might cause additional alterations in the plant phenotype. Here, we studied changes in the amino acid (AA) content in the phloem of chilli (Capsicum annuum) plants infected with Pepper golden mosaic virus (PepGMV) upon subsequent colonization with a non-vector, the phloem-feeding whitefly (Trialeurodes vaporariorum). Virus infection alone caused an almost 30-fold increase in overall phloem AAs, but colonization by T. vaporariorum completely reversed this effect. At the level of individual AAs, contents of proline, tyrosine, and valine increased, and histidine and alanine decreased in PepGMV -infected as compared to control plants, whereas colonization by T. vaporariorum caused decreased contents of proline, tyrosine, and valine, and increased contents of histidine and alanine. Overall, the colonization by the whitefly had much stronger effects on phloem AA composition than virus infection. We conclude that the phloem composition of a virus-infected host plant can rapidly change upon arrival of an herbivore and that these changes need to be monitored to predict the nutritional quality of the plant in the long run.

  18. Higher plant metabolism and energetics in hypogravity: Amino acid metabolism in higher plants

    NASA Technical Reports Server (NTRS)

    Mazelis, M.

    1976-01-01

    Laboratory's investigation into the amino acid metabolism of dwarf marigolds exposed to an environment of simulated hypogravity is summarized. Using both in vivo, and/or in vitro studies, the following effects of hypogravitational stress have been shown: (1) increased proline incorporation into cell wall protein, (2) inhibition of amino acid decarboxylation, (3) decrease in glutamic acid decarboxylase activity; and (4) decrease in the relative amount of a number of soluble amino acids present in deproteinized extracts of marigold leaves. It is concluded from these data there are several rapid, major alterations in amino acid metabolism associated with hypogravitational stress in marigolds. The mechanism(s) and generality of these effects with regard to other species is still unknown.

  19. Fatty acid constituents of Peganum harmala plant using Gas Chromatography–Mass Spectroscopy

    PubMed Central

    Moussa, Tarek A.A.; Almaghrabi, Omar A.

    2015-01-01

    Fatty acid contents of the Peganum harmala plant as a result of hexane extraction were analyzed using GC–MS. The saturated fatty acid composition of the harmal plant was tetradecanoic, pentadecanoic, tridecanoic, hexadecanoic, heptadecanoic and octadecanoic acids, while the saturated fatty acid derivatives were 12-methyl tetradecanoic, 5,9,13-trimethyl tetradecanoic and 2-methyl octadecanoic acids. The most abundant fatty acid was hexadecanoic with concentration 48.13% followed by octadecanoic with concentration 13.80%. There are four unsaturated fatty acids called (E)-9-dodecenoic, (Z)-9-hexadecenoic, (Z,Z)-9,12-octadecadienoic and (Z,Z,Z)-9,12,15-octadecatrienoic. The most abundant unsaturated fatty acid was (Z,Z,Z)-9,12,15-octadecatrienoic with concentration 14.79% followed by (Z,Z)-9,12-octadecadienoic with concentration 10.61%. Also, there are eight non-fatty acid compounds 1-octadecene, 6,10,14-trimethyl-2-pentadecanone, (E)-15-heptadecenal, oxacyclohexadecan-2 one, 1,2,2,6,8-pentamethyl-7-oxabicyclo[4.3.1]dec-8-en-10-one, hexadecane-1,2-diol, n-heneicosane and eicosan-3-ol. PMID:27081366

  20. Fatty acid constituents of Peganum harmala plant using Gas Chromatography-Mass Spectroscopy.

    PubMed

    Moussa, Tarek A A; Almaghrabi, Omar A

    2016-05-01

    Fatty acid contents of the Peganum harmala plant as a result of hexane extraction were analyzed using GC-MS. The saturated fatty acid composition of the harmal plant was tetradecanoic, pentadecanoic, tridecanoic, hexadecanoic, heptadecanoic and octadecanoic acids, while the saturated fatty acid derivatives were 12-methyl tetradecanoic, 5,9,13-trimethyl tetradecanoic and 2-methyl octadecanoic acids. The most abundant fatty acid was hexadecanoic with concentration 48.13% followed by octadecanoic with concentration 13.80%. There are four unsaturated fatty acids called (E)-9-dodecenoic, (Z)-9-hexadecenoic, (Z,Z)-9,12-octadecadienoic and (Z,Z,Z)-9,12,15-octadecatrienoic. The most abundant unsaturated fatty acid was (Z,Z,Z)-9,12,15-octadecatrienoic with concentration 14.79% followed by (Z,Z)-9,12-octadecadienoic with concentration 10.61%. Also, there are eight non-fatty acid compounds 1-octadecene, 6,10,14-trimethyl-2-pentadecanone, (E)-15-heptadecenal, oxacyclohexadecan-2 one, 1,2,2,6,8-pentamethyl-7-oxabicyclo[4.3.1]dec-8-en-10-one, hexadecane-1,2-diol, n-heneicosane and eicosan-3-ol.

  1. Tundra plant uptake of amino acid and NH{sub 4}{sup +} nitrogen in situ: Plants compete well for amino acid N{sup 1}

    SciTech Connect

    Schimel, J.P.; Chapin, F.S. III

    1996-10-01

    Traditional models of nutrient cycling assume that soil microorganisms must decompose organic matter, releasing inorganic N, to make N available to plants. Several lines of evidence have raised doubts about this assumption in arctic tundra, but no firm evidence existed. Here we demonstrate that Eriophorum vaginatum and Carex aquatilis, two tundra sedges, compete well for glycine and asparate N relative to NH{sub 4}{sup +} in situ. At relatively high concentrations (25 {mu}g N/g soil), during the peak of the season, E. vaginatum took up amino acid N more rapidly than NH{sub 4}{sup +}, while later in the season and at lower concentrations (2-4 {mu}g N/g soil) both E. vaginatum and C. aqualtilis took up glycine N and NH{sub 4}{sup +} at similar rates. These results are incompatible with a simple mechanism of amino acid mineralization followed by plant uptake of the released N. These results indicate that these tundra plants have active mechanisms for enhancing their access to amino acid N in situ. 18 refs., 4 tabs.

  2. Good and bad protons: genetic aspects of acidity stress responses in plants.

    PubMed

    Shavrukov, Yuri; Hirai, Yoshihiko

    2016-01-01

    Physiological aspects of acidity stress in plants (synonymous with H(+) rhizotoxicity or low-pH stress) have long been a focus of research, in particular with respect to acidic soils where aluminium and H(+) rhizotoxicities often co-occur. However, toxic H(+) and Al(3+) elicit different response mechanisms in plants, and it is important to consider their effects separately. The primary aim of this review was to provide the current state of knowledge regarding the genetics of the specific reactions to low-pH stress in growing plants. A comparison of the results gleaned from quantitative trait loci analysis and global transcriptome profiling of plants in response to high proton concentrations revealed a two-stage genetic response: (i) in the short-term, proton pump H(+)-ATPases present the first barrier in root cells, allocating an excess of H(+) into either the apoplast or vacuole; the ensuing defence signaling system involves auxin, salicylic acid, and methyl jasmonate, which subsequently initiate expression of STOP and DREB transcription factors as well as chaperone ROF; (2) the long-term response includes other genes, such as alternative oxidase and type II NAD(P)H dehydrogenase, which act to detoxify dangerous reactive oxygen species in mitochondria, and help plants better manage the stress. A range of transporter genes including those for nitrate (NTR1), malate (ALMT1), and heavy metals are often up-regulated by H(+) rhizotoxicity. Expansins, cell-wall-related genes, the γ-aminobutyric acid shunt and biochemical pH-stat genes also reflect changes in cell metabolism and biochemistry in acidic conditions. However, the genetics underlying the acidity stress response of plants is complicated and only fragmentally understood.

  3. Salicylic acid-induced abiotic stress tolerance and underlying mechanisms in plants

    PubMed Central

    Khan, M. Iqbal R.; Fatma, Mehar; Per, Tasir S.; Anjum, Naser A.; Khan, Nafees A.

    2015-01-01

    Abiotic stresses (such as metals/metalloids, salinity, ozone, UV-B radiation, extreme temperatures, and drought) are among the most challenging threats to agricultural system and economic yield of crop plants. These stresses (in isolation and/or combination) induce numerous adverse effects in plants, impair biochemical/physiological and molecular processes, and eventually cause severe reductions in plant growth, development and overall productivity. Phytohormones have been recognized as a strong tool for sustainably alleviating adverse effects of abiotic stresses in crop plants. In particular, the significance of salicylic acid (SA) has been increasingly recognized in improved plant abiotic stress-tolerance via SA-mediated control of major plant-metabolic processes. However, the basic biochemical/physiological and molecular mechanisms that potentially underpin SA-induced plant-tolerance to major abiotic stresses remain least discussed. Based on recent reports, this paper: (a) overviews historical background and biosynthesis of SA under both optimal and stressful environments in plants; (b) critically appraises the role of SA in plants exposed to major abiotic stresses; (c) cross-talks potential mechanisms potentially governing SA-induced plant abiotic stress-tolerance; and finally (d) briefly highlights major aspects so far unexplored in the current context. PMID:26175738

  4. Responses of herbivore and predatory mites to tomato plants exposed to jasmonic acid seed treatment.

    PubMed

    Smart, Lesley E; Martin, Janet L; Limpalaër, Marlène; Bruce, Toby J A; Pickett, John A

    2013-10-01

    Jasmonic acid (JA) signalling can influence plant defense and the production of plant volatiles that mediate interactions with insects. Here, we tested whether a JA seed treatment could alter direct and indirect defenses. First, oviposition levels of herbivorous mites, Tetranychus urticae, on JA seed-treated and control tomato plants were compared. They were not significantly different on tomato cv. 'Moneymaker', however, there was a significant reduction in oviposition on treated plants in additional experiments with cv. 'Carousel'. Second, responses of predatory mites, Phytoseiulus persimilis, were assessed in a Y-tube olfactometer. Volatiles from JA seed-treated tomato cv. 'Moneymaker' plants were significantly more attractive than volatiles from control plants. Volatiles collected from plants were analysed by GC/MS, and samples from JA seed-treated plants contained more methyl salicylate and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT) than samples from control plants. Our results indicate that JA seed treatment can make tomato plants more attractive to predatory mites, but that direct effects on herbivorous mites are variable and cultivar dependent.

  5. Nitro-fatty acids in plant signaling: New key mediators of nitric oxide metabolism.

    PubMed

    Mata-Pérez, Capilla; Sánchez-Calvo, Beatriz; Padilla, María N; Begara-Morales, Juan C; Valderrama, Raquel; Corpas, Francisco J; Barroso, Juan B

    2017-04-01

    Recent studies in animal systems have shown that NO can interact with fatty acids to generate nitro-fatty acids (NO2-FAs). They are the product of the reaction between reactive nitrogen species and unsaturated fatty acids, and are considered novel mediators of cell signaling based mainly on a proven anti-inflammatory response. Although these signaling mediators have been described widely in animal systems, NO2-FAs have scarcely been studied in plants. Preliminary data have revealed the endogenous presence of free and protein-adducted NO2-FAs in extra-virgin olive oil (EVOO), which appear to be contributing to the cardiovascular benefits associated with the Mediterranean diet. Importantly, new findings have displayed the endogenous occurrence of nitro-linolenic acid (NO2-Ln) in the model plant Arabidopsis thaliana and the modulation of NO2-Ln levels throughout this plant's development. Furthermore, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO2-Ln was involved in plant-defense response against different abiotic-stress conditions, mainly by inducing the chaperone network and supporting a conserved mechanism of action in both animal and plant defense processes. Thus, NO2-Ln levels significantly rose under several abiotic-stress conditions, highlighting the strong signaling role of these molecules in the plant-protection mechanism. Finally, the potential of NO2-Ln as a NO donor has recently been described both in vitro and in vivo. Jointly, this ability gives NO2-Ln the potential to act as a signaling molecule by the direct release of NO, due to its capacity to induce different changes mediated by NO or NO-related molecules such as nitration and S-nitrosylation, or by the electrophilic capacity of these molecules through a nitroalkylation mechanism. Here, we describe the current state of the art regarding the advances performed in the field of NO2-FAs in plants and their implication in plant

  6. In situ phytostabilisation capacity of three legumes and their associated Plant Growth Promoting Bacteria (PGPBs) in mine tailings of northern Tunisia.

    PubMed

    Saadani, Omar; Fatnassi, Imen Challougui; Chiboub, Manel; Abdelkrim, Souhir; Barhoumi, Fathi; Jebara, Moez; Jebara, Salwa Harzalli

    2016-08-01

    PGPBs-legumes associations represent an alternative procedure for phytostabilisation of heavy metals polluted soils mainly generated by industrial and agricultural practices. In this study we evaluated the capacity of Vicia faba, Lens culinaris and Sulla coronaria, inoculated in situ by specific heavy metals resistant inocula, for the phytostabilisation of copper, lead and cadmium respectively. The experimentation was performed in mine tailings of northern Tunisia. Results proved that inoculation enhanced roots and shoots biomass production of faba bean by 14% and 12%, respectively, and significantly improved pods yield by 91%. In lentil, the inoculation ameliorated shoot biomass up to 27%. The highest nitrogen fixation was recorded by Sulla coronaria. The three symbioses accumulated heavy metals essentially in roots, and poorly in shoots. In addition, cadmium accumulation in roots of inoculated sulla was enhanced by 39%. Furthermore, inoculations decreased heavy metals availability in the soil up to -10% of Cu and -47% of Pb respectively in roots of faba bean and lentil. Our results suggested a positive effect of co-inoculation of legumes by appropriate heavy metals resistant PGPBs for the phytostabilisation of mine tailings. Elsewhere, the enhancement in the antioxidant enzymes activities demonstrated the role of the three inocula to alleviate the heavy metals induced stress.

  7. Marsh plant response to metals: Exudation of aliphatic low molecular weight organic acids (ALMWOAs)

    NASA Astrophysics Data System (ADS)

    Rocha, A. Cristina S.; Almeida, C. Marisa R.; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

    2016-03-01

    Metal exposure is known to induce the production and secretion of substances, such as aliphatic low molecular weight organic acids (ALMWOAs), into the rhizosphere by plant roots. Knowledge on this matter is extensive for soil plants but still considerably scarce regarding marsh plants roots adapted to high salinity media. Phragmites australis and Halimione portulacoides, two marsh plants commonly distributed in European estuarine salt marshes, were used to assess the response of roots of both species, in terms of ALMWOAs exudation, to Cu, Ni and Cd exposure (isolated and in mixture since in natural environment, they are exposed to mixture of metals). As previous studies were carried out in unrealistic and synthetic media, here a more natural medium was selected. Therefore, in vitro experiments were carried out, with specimens of both marsh plants, and in freshwater contaminated with two different Cu, Ni and Cd concentrations (individual metal and in mixture). Both marsh plants were capable of liberating ALMWOAs into the surrounding medium. Oxalic, citric and maleic acids were found in P. australis root exudate solutions and oxalic and maleic acids in H. portulacoides root exudate solutions. ALMWOA liberation by both plants was plant species and metal-dependent. For instance, Cu affected the exudation of oxalic acid by H. portulacoides and of oxalic and citric acids by P. australis roots. In contrast, Ni and Cd did not stimulate any specific response. Regarding the combination of all metals, H. portulacoides showed a similar response to that observed for Cu individually. However, in the P. australis case, at high metal concentration mixture, a synergetic effect led to the increase of oxalic acid levels in root exudate solution and to a decrease of citric acid liberation. A correlation between ALMWOAs exudation and metal accumulation could not be established. P. australis and H. portulacoides are considered suitable metal phytoremediators of estuarine impacted areas

  8. Methods for extraction and determination of phenolic acids in medicinal plants: a review.

    PubMed

    Arceusz, Agnieszka; Wesolowski, Marek; Konieczynski, Pawel

    2013-12-01

    Phenolic acids constitute a group of potentially immunostimulating compounds. They occur in all medicinal plants and are widely used in phytotherapy and foods of plant origin. In recent years, phenolic acids have attracted much interest owing to their biological functions. This paper reviews the extraction and determination methods of phenolic acids in medicinal plants over the last 10 years. Although Soxhlet extraction and ultrasonic assisted extraction (UAE) are commonly used for the extraction of phenolic acids from plant materials, alternative techniques such as supercritical fluid extraction (SFE), and accelerated solvent extraction (ASE) can also be used. After extraction, phenolic acids are determined usually by liquid chromatography (LC) owing to the recent developments in this technique, especially when it is coupled with mass spectrometry (MS). Also detection systems are discussed, including UV-Vis, diode array, electrochemical and fluorimetric. Other popular techniques for the analysis of this group of secondary metabolites are gas chromatography coupled with mass spectrometry (GC-MS) and capillary electrophoresis (CE).

  9. Aluminium-phosphorus interactions in plants growing on acid soils: does phosphorus always alleviate aluminium toxicity?

    PubMed

    Chen, Rong Fu; Zhang, Fu Lin; Zhang, Qi Ming; Sun, Qing Bin; Dong, Xiao Ying; Shen, Ren Fang

    2012-03-30

    Aluminium (Al) toxicity and phosphorus (P) deficiency are considered to be the main constraints for crop production in acid soils, which are widely distributed in tropical and subtropical regions. Conventionally, P addition is regarded as capable of alleviating Al toxicity in plants. However, this field is still rife with unsubstantiated theories, especially for different plant species growing on acid soils. In this review, the responses of plants to different methods of Al-P treatments are briefly summarized, and possible reasons are proposed by considering recent results from our laboratory. It is shown that: (1) long-term Al-P alternate treatment is advantageous for studying Al-P interactions in plants; (2) under the long-term Al-P alternate treatment, the roles of P in Al phytotoxicity might be associated with the Al resistance capability and P use efficiency of the plant, and a P/Al molar ratio exceeding 5 in roots may be the threshold of P alleviating Al toxicity based on the calculation of the tested plants; (3) in acid soils, P application may be effective only after Al stress is overcome for Al-sensitive species. Thus it is concluded that P application does not always alleviate Al toxicity under long-term Al-P alternate treatment.

  10. Biostimulation of PAH degradation with plants containing high concentrations of linoleic acid.

    PubMed

    Yi, Haakrho; Crowley, David E

    2007-06-15

    Many plant species enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs), but there is little understanding of the mechanisms by which this occurs. This research identified phytochemicals that stimulate pyrene degradation using crushed roottissues from 43 plants that were screened in soil spiked with 100 ppm pyrene. Among the plants tested, root tissues from Apium graveolens (celery), Raphanus sativus (radish), Solanum tuberosum (potato), and Daucus carota (carrot) were most effective for promoting disappearance of pyrene within 40 days. Experiments with A. graveolens showed that plant culture in soil contaminated with pyrene or benzo[a]pyrene was as effective as addition of crushed root tissues. Comparison of the chemical compositions of the effective plants suggested that linoleic acid was the major substance that stimulated PAH degradation. This hypothesis was supported in experiments examining degradation of pyrene and benzo[a]pyrene in soil amended with linoleate, whereas linolenic and palmitic acids did not stimulate degradation within a 20 day period. Antibiotic inhibitor studies implicated gram positive bacteria as a predominant group responding to linoleic acid. These findings provide insight into the mechanisms by which plants enhance degradation of PAHs, and have practical application for remediation of PAH contaminated soils.

  11. Salicylic Acid, a Plant Defense Hormone, Is Specifically Secreted by a Molluscan Herbivore

    PubMed Central

    Kästner, Julia; von Knorre, Dietrich; Himanshu, Himanshu; Erb, Matthias; Baldwin, Ian T.; Meldau, Stefan

    2014-01-01

    Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding. PMID:24466122

  12. Antithrombosis activity of protocatechuic and shikimic acids from functional plant Pinus densiflora Sieb. et Zucc needles.

    PubMed

    Park, Jaeyoung; Lee, Beomgi; Choi, Hakjoon; Kim, Woong; Kim, Ho-Joong; Cheong, Hyeonsook

    2016-07-01

    Pine needle extract (PE) and fermented pine needle extract (FPE) have been reported to show various biological and pharmacological activities such as antioxidant, anti-inflammatory, anti-bacterial, anti-cholesterol, gastrointestinal motility control, and fibrinolytic effect. The aims of our research were to isolate fibrinolytic compounds from PE and FPE and evaluate their antithrombotic activity in vitro and in vivo. Protocatechuic (1) and shikimic (2) acids were isolated and identified from FPE. 1 and 2 not only have fibrinolysis activity but also inhibit fibrin formation similar to aspirin. Lysis of fibrin clots by 1 and 2 occurred completely at pH 2-4. Results of SDS-PAGE showed that fibrin polypeptide chains (Aα, Bβ, γ) lysed by 1 and 2 were intact. The antithrombotic effects of 1 and 2 were confirmed by models of carrageenan-induced tail thrombosis, collagen and epinephrine-induced pulmonary thromboembolism in mice, and FeCl3-induced carotid arterial thrombus. Moreover, 1 and 2 did not induce hemorrhage in the tail veins of mice, unlike common antithrombotic compounds. We also measured changes in the quantities of 1 and 2 obtained from FPE. As fermentation progressed, we demonstrated that the quantity of 1 steadily increased, while the quantity of 2 did not significantly change. We therefore demonstrated that FPE is an excellent resource for 1 and 2 and can be produced inexpensively in sufficient quantities for industrial-scale extraction.

  13. Evaluation of mineral elements and ascorbic acid contents in fruits of some wild plants.

    PubMed

    Eromosele, I C; Eromosele, C O; Kuzhkuzha, D M

    1991-04-01

    The fruits of some wild plants were examined for their contents of mineral elements and ascorbic acid. High levels of ascorbic acid were found in fruits of Sclerocarya birrea (403.3 mg/100 g) and Adansonia digitata (337 mg/100 g). In nine of the fruits examined, the mineral contents (Ca, P) were comparable with average values found in common fruits. The iron contents were however 2-5 times higher than the values for common fruits.

  14. Hexanoic acid is a resistance inducer that protects tomato plants against Pseudomonas syringae by priming the jasmonic acid and salicylic acid pathways.

    PubMed

    Scalschi, Loredana; Vicedo, Begonya; Camañes, Gemma; Fernandez-Crespo, Emma; Lapeña, Leonor; González-Bosch, Carmen; García-Agustín, Pilar

    2013-05-01

    Hexanoic acid-induced resistance (Hx-IR) is effective against several pathogens in tomato plants. Our study of the mechanisms implicated in Hx-IR against Pseudomonas syringae pv. tomato DC3000 suggests that hexanoic acid (Hx) treatment counteracts the negative effect of coronatine (COR) and jasmonyl-isoleucine (JA-Ile) on the salicylic acid (SA) pathway. In Hx-treated plants, an increase in the expression of jasmonic acid carboxyl methyltransferase (JMT) and the SA marker genes PR1 and PR5 indicates a boost in this signalling pathway at the expense of a decrease in JA-Ile. Moreover, Hx treatment potentiates 12-oxo-phytodienoic acid accumulation, which suggests that this molecule might play a role per se in Hx-IR. These results support a positive relationship between the SA and JA pathways in Hx-primed plants. Furthermore, one of the mechanisms of virulence mediated by COR is stomatal re-opening on infection with P. syringae. In this work, we observed that Hx seems to inhibit stomatal opening in planta in the presence of COR, which suggests that, on infection in tomato, this treatment suppresses effector action to prevent bacterial entry into the mesophyll.

  15. Response of citrus and other selected plant species to simulated HCL - acid rain

    NASA Technical Reports Server (NTRS)

    Knott, W. M.; Heagle, A. S.

    1980-01-01

    Mature valencia orange trees were sprayed with hydrochloric acid solutions (pH 7.8, 2.0, 1.0, and 0.5) in the field at the full bloom stage and at one month after fruit set. Potted valencia orange and dwarf citrus trees, four species of plants native to Merritt Island, and four agronomic species were exposed to various pH levels of simulated acid rain under controlled conditions. The acid rain was generated from dilutions of hydrochloric acid solutions or by passing water through an exhaust generated by burning solid rocket fuel. The plants were injured severely at pH levels below 1.0, but showed only slight injury at pH levels of 2.0 and above. Threshold injury levels were between 2.0 and 3.0 pH. The sensitivity of the different plant species to acid solutions was similar. Foliar injury symptoms were representative of acid rain including necrosis of young tissue, isolated necrotic spots or patches, and leaf abscission. Mature valencia orange trees sprayed with concentrations of 1.0 pH and 0.5 pH in the field had reduced fruit yields for two harvests after the treatment. All experimental trees were back to full productivity by the third harvest after treatment.

  16. Occurrence of several acidic drugs in sewage treatment plants in Switzerland and risk assessment.

    PubMed

    Tauxe-Wuersch, A; De Alencastro, L F; Grandjean, D; Tarradellas, J

    2005-05-01

    The occurrence and fate of five acidic drugs (Mefenamic acid, Ibuprofen, Ketoprofen, Diclofenac and Clofibric acid) were analysed in three sewage treatment plants (STP) over 4-7 consecutive days. The results point out that the five substances were persistent in wastewater effluents after municipal wastewater treatment. At the most, half of Mefenamic acid was eliminated. Ibuprofen was well removed (80%) by one sewage treatment plant. The removal of Ibuprofen is dependent on the residence time of wastewater in the STPs. A long raining period induce an important decrease of removal of Ibuprofen and Ketoprofen. Removal rates showed a great variability according to sewage treatment plants and types of treatments (e.g. biological, physico-chemical). The concentrations of Ibuprofen, Mefenamic acid and Diclofenac were relatively high in the effluents (150-2000 ng/l), showing a potential contamination of surface water. An environmental risk assessment is presented. Mefenamic acid seems to present a risk for the aquatic environment, with a ratio PEC/PNEC higher than one.

  17. Roles of Organic Acid Anion Secretion in Aluminium Tolerance of Higher Plants

    PubMed Central

    Yang, Lin-Tong; Qi, Yi-Ping; Jiang, Huan-Xin; Chen, Li-Song

    2013-01-01

    Approximately 30% of the world's total land area and over 50% of the world's potential arable lands are acidic. Furthermore, the acidity of the soils is gradually increasing as a result of the environmental problems including some farming practices and acid rain. At mildly acidic or neutral soils, aluminium(Al) occurs primarily as insoluble deposits and is essentially biologically inactive. However, in many acidic soils throughout the tropics and subtropics, Al toxicity is a major factor limiting crop productivity. The Al-induced secretion of organic acid (OA) anions, mainly citrate, oxalate, and malate, from roots is the best documented mechanism of Al tolerance in higher plants. Increasing evidence shows that the Al-induced secretion of OA anions may be related to the following several factors, including (a) anion channels or transporters, (b) internal concentrations of OA anions in plant tissues, (d) temperature, (e) root plasma membrane (PM) H+-ATPase, (f) magnesium (Mg), and (e) phosphorus (P). Genetically modified plants and cells with higher Al tolerance by overexpressing genes for the secretion and the biosynthesis of OA anions have been obtained. In addition, some aspects needed to be further studied are also discussed. PMID:23509687

  18. Roles of organic acid anion secretion in aluminium tolerance of higher plants.

    PubMed

    Yang, Lin-Tong; Qi, Yi-Ping; Jiang, Huan-Xin; Chen, Li-Song

    2013-01-01

    Approximately 30% of the world's total land area and over 50% of the world's potential arable lands are acidic. Furthermore, the acidity of the soils is gradually increasing as a result of the environmental problems including some farming practices and acid rain. At mildly acidic or neutral soils, aluminium (Al) occurs primarily as insoluble deposits and is essentially biologically inactive. However, in many acidic soils throughout the tropics and subtropics, Al toxicity is a major factor limiting crop productivity. The Al-induced secretion of organic acid (OA) anions, mainly citrate, oxalate, and malate, from roots is the best documented mechanism of Al tolerance in higher plants. Increasing evidence shows that the Al-induced secretion of OA anions may be related to the following several factors, including (a) anion channels or transporters, (b) internal concentrations of OA anions in plant tissues, (d) temperature, (e) root plasma membrane (PM) H(+)-ATPase, (f) magnesium (Mg), and (e) phosphorus (P). Genetically modified plants and cells with higher Al tolerance by overexpressing genes for the secretion and the biosynthesis of OA anions have been obtained. In addition, some aspects needed to be further studied are also discussed.

  19. Acid fuel cell technologies for vehicular power plants

    SciTech Connect

    Huff, J.R.; Srinivasan, S.

    1982-08-01

    Fuel cells offer a number of significant advantages as vehicular power sources. These include high efficiency, virtually no pollution, and the ability to use nonpetroleum fuel. To date, most fuel cell systems have been designed for either utility or space applications, which have substantially different requirements than vehicular applications. Several fuel cell technologies were assessed specifically for vehicular applications. The results of these assessments were used to calculate the performance and fuel consumption of a fuel cell powered GM X car. Results indicate that the phosphoric acid technology, which has the most development experience, can power a vehicle with reasonable performance, with a range of over 350 miles on 20 gallons of methanol and with high energy efficiency. Solid polymer electrolyte technology, which is second in development experience, can provide performance approaching that of an ICE vehicle and an energy efficiency 149% higher than the ICE-powered version.

  20. Crassulacean acid metabolism (CAM) in an epiphytic ant-plant, Myrmecodia beccarii Hook.f. (Rubiaceae).

    PubMed

    Tsen, Edward W J; Holtum, Joseph A M

    2012-09-01

    This study demonstrates unequivocally the presence of crassulacean acid metabolism (CAM) in a species of the Rubiaceae, the fourth largest angiosperm plant family. The tropical Australian endemic epiphytic ant-plant, Myrmecodia beccarii Hook.f., exhibits net CO(2) uptake in the dark and a concomitant accumulation of titratable acidity in plants in the field and in cultivation. Plants growing near Cardwell, in a north Queensland coastal seasonally dry forest of Melaleuca viridiflora Sol. ex Gaertn., accumulated ~50 % of their 24 h carbon gain in the dark during the warm wet season. During the transition from the wet season to the dry season, 24 h carbon gain was reduced whilst the proportion of carbon accumulated during the dark increased. By mid dry season many plants exhibited zero net carbon uptake over 24 h, but CO(2) uptake in the dark was observed in some plants following localised rainfall. In a shade-house experiment, droughted plants in which CO(2) uptake in the light was absent and dark CO(2) uptake was reduced, were able to return to relatively high rates of CO(2) uptake in the light and dark within 12 h of rewatering.

  1. Engineering assessment of inactive uranium mill tailings

    SciTech Connect

    Not Available

    1981-07-01

    The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost estimated to be about $41,900,000. Three principal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive.

  2. Safety assessment of animal- and plant-derived amino acids as used in cosmetics.

    PubMed

    Burnett, Christina; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2014-01-01

    The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of animal- and plant-derived amino acid mixtures, which function as skin and hair conditioning agents. The safety of α-amino acids as direct food additives has been well established, based on extensive research through acute and chronic dietary exposures and the Panel previously has reviewed the safety of individual α-amino acids in cosmetics. The Panel focused its review on dermal irritation and sensitization data relevant to the use of these ingredients in topical cosmetics. The Panel concluded that these 21 ingredients are safe in the present practices of use and concentration as used in cosmetics.

  3. Abscisic acid has a key role in modulating diverse plant-pathogen interactions.

    PubMed

    Fan, Jun; Hill, Lionel; Crooks, Casey; Doerner, Peter; Lamb, Chris

    2009-08-01

    We isolated an activation-tagged Arabidopsis (Arabidopsis thaliana) line, constitutive disease susceptibility2-1D (cds2-1D), that showed enhanced bacterial growth when challenged with various Pseudomonas syringae strains. Systemic acquired resistance and systemic PATHOGENESIS-RELATED GENE1 induction were also compromised in cds2-1D. The T-DNA insertion adjacent to NINE-CIS-EPOXYCAROTENOID DIOXYGENASE5 (NCED5), one of six genes encoding the abscisic acid (ABA) biosynthetic enzyme NCED, caused a massive increase in transcript level and enhanced ABA levels >2-fold. Overexpression of NCED genes recreated the enhanced disease susceptibility phenotype. NCED2, NCED3, and NCED5 were induced, and ABA accumulated strongly following compatible P. syringae infection. The ABA biosynthetic mutant aba3-1 showed reduced susceptibility to virulent P. syringae, and ABA, whether through exogenous application or endogenous accumulation in response to mild water stress, resulted in increased bacterial growth following challenge with virulent P. syringae, indicating that ABA suppresses resistance to P. syringae. Likewise ABA accumulation also compromised resistance to the biotrophic oomycete Hyaloperonospora arabidopsis, whereas resistance to the fungus Alternaria brassicicola was enhanced in cds2-1D plants and compromised in aba3-1 plants, indicating that ABA promotes resistance to this necrotroph. Comparison of the accumulation of salicylic acid and jasmonic acid in the wild type, cds2-1D, and aba3-1 plants challenged with P. syringae showed that ABA promotes jasmonic acid accumulation and exhibits a complex antagonistic relationship with salicylic acid. Our findings provide genetic evidence that the abiotic stress signal ABA also has profound roles in modulating diverse plant-pathogen interactions mediated at least in part by cross talk with the jasmonic acid and salicylic acid biotic stress signal pathways.

  4. Effect of Salicylic Acid on Somatic Embryogenesis and Plant Regeneration in Hedychium bousigonianum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to induce somatic embryogenesis in Hedychium bousigonianum Pierre ex Gagnepain and assess the influence of salicylic acid (S) on somatic embryogenesis. Somatic embryos and subsequently regenerated plants were successfully obtained 30 days after transfer of embryogenic...

  5. Using heat pipe to make isotherm condition in catalytic converters of sulfuric acid plants

    NASA Astrophysics Data System (ADS)

    Yousefi, M.; Pahlavanzadeh, H.; Sadrameli, S. M.

    2017-03-01

    In this study, for the first time, it is tried to construct a pilot reactor, for surveying the possibility of creating isothermal condition in the catalytic convertors where SO2 is converted to SO3 in the sulfuric acid plants by heat pipe. The thermodynamic and thermo-kinetic conditions were considered the same as the sulfuric acid plants converters. Also, influence of SO2 gas flow rate on isothermal condition, has been studied. A thermo-siphon type heat pipe contains the sulfur + 5% iodine as working fluid, was used for disposing the heat of reaction from catalytic bed. Our results show that due to very high energy-efficiency, isothermal and passive heat transfer mechanism of heat pipe, it is possible to reach more than 95% conversion in one isothermal catalytic bed. As the results, heat pipe can be used as a certain piece of equipment to create isothermal condition in catalytic convertors of sulphuric acid plants. With this work a major evaluation in design of sulphuric acid plants can be taken place.

  6. Effect of acid solutions on plants studied by the optical beam deflection method.

    PubMed

    Nie, Liangjiao; Kuboda, Mitsutoshi; Inoue, Tomomi; Wu, Xingzheng

    2013-12-01

    The optical beam deflection method was applied to study the effects of acid solution on both a terrestial and aquatic plants Egeria and Cerastium, which are common aquatic plant and terrestial weed respectively. A probe beam from a He-Ne laser was passed through a vicinity of a leaf of the plants, which were put in culture dishes filled with acid solutions. Deflection signals of the probe beam were monitored and compared for acid solutions with different pH values. The results of Egria showed that the deflection signals changed dramatically when pH values of acid solutions were 2.0 and 3.0, while little at pH of 4.0 and 5.0. For Cerastium when pH were below 3.0, deflection signals changed greatly with time at the begining. After a certain period of time, deflection signals changed little with time. When pH value was above 4.0, deflection signals of Cerastium were still changing with time even after 20 hours. The results suggested that the damage threshold of pH was between 3.0 and 4.0 for both the land and aquatic plants.

  7. Fatty acid unsaturation, mobilization, and regulation in the response of plants to stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stress acclimating plants respond to abiotic and biotic stress by remodeling membrane fluidity and the release of a-linolenic from membrane lipid. The adjustment of membrane lipid fluidity occurs through changes in unsaturated fatty acid levels, a function provided by the regulated activity of...

  8. Priming of plant resistance by natural compounds. Hexanoic acid as a model

    PubMed Central

    Aranega-Bou, Paz; de la O Leyva, Maria; Finiti, Ivan; García-Agustín, Pilar; González-Bosch, Carmen

    2014-01-01

    Some alternative control strategies of currently emerging plant diseases are based on the use of resistance inducers. This review highlights the recent advances made in the characterization of natural compounds that induce resistance by a priming mechanism. These include vitamins, chitosans, oligogalacturonides, volatile organic compounds, azelaic and pipecolic acid, among others. Overall, other than providing novel disease control strategies that meet environmental regulations, natural priming agents are valuable tools to help unravel the complex mechanisms underlying the induced resistance (IR) phenomenon. The data presented in this review reflect the novel contributions made from studying these natural plant inducers, with special emphasis placed on hexanoic acid (Hx), proposed herein as a model tool for this research field. Hx is a potent natural priming agent of proven efficiency in a wide range of host plants and pathogens. It can early activate broad-spectrum defenses by inducing callose deposition and the salicylic acid (SA) and jasmonic acid (JA) pathways. Later it can prime pathogen-specific responses according to the pathogen’s lifestyle. Interestingly, Hx primes redox-related genes to produce an anti-oxidant protective effect, which might be critical for limiting the infection of necrotrophs. Our Hx-IR findings also strongly suggest that it is an attractive tool for the molecular characterization of the plant alarmed state, with the added advantage of it being a natural compound. PMID:25324848

  9. Manual of phosphoric acid fuel cell power plant cost model and computer program

    NASA Technical Reports Server (NTRS)

    Lu, C. Y.; Alkasab, K. A.

    1984-01-01

    Cost analysis of phosphoric acid fuel cell power plant includes two parts: a method for estimation of system capital costs, and an economic analysis which determines the levelized annual cost of operating the system used in the capital cost estimation. A FORTRAN computer has been developed for this cost analysis.

  10. A Continuous, Quantitative Fluorescent Assay for Plant Caffeic acid O-Methyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant caffeic acid O-methyltransferases (COMTs) use s-adenosylmethionine (ado-met), as a methyl donor to transmethylate their preferred (phenolic) substrates in-vivo, and will generally utilize a range of phenolic compounds in-vitro. Collazo et al. (2005; Analytical Biochemistry 342: 86-92) have pu...

  11. Fatty acid profile of 25 plant oils and implications for industrial applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fatty acid (FA) profiles of plant oils extracted from twenty-five alternative feedstocks were determined. This information was utilized to determine what industrial application(s) each oil is best suited for. The basis for the selection was the premise that FA composition influences properties o...

  12. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant unde...

  13. A Potent Plant-Derived Antifungal Acetylenic Acid Mediates Its Activity by Interfering with Fatty Acid Homeostasis

    PubMed Central

    Xu, Tao; Tripathi, Siddharth K.; Feng, Qin; Lorenz, Michael C.; Wright, Marsha A.; Jacob, Melissa R.; Mask, Melanie M.; Baerson, Scott R.; Li, Xing-Cong; Clark, Alice M.

    2012-01-01

    6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model yeast Saccharomyces cerevisiae to investigate its mechanism of action. 6-NDA elicited a transcriptome response indicative of fatty acid stress, altering the expression of genes that are required for yeast growth in the presence of oleate. Mutants of S. cerevisiae lacking transcription factors that regulate fatty acid β-oxidation showed increased sensitivity to 6-NDA. Fatty acid profile analysis indicated that 6-NDA inhibited the formation of fatty acids longer than 14 carbons in length. In addition, the growth inhibitory effect of 6-NDA was rescued in the presence of exogenously supplied oleate. To investigate the response of a pathogenic fungal species to 6-NDA, transcriptional profiling and biochemical analyses were also conducted in C. albicans. The transcriptional response and fatty acid profile of C. albicans were comparable to those obtained in S. cerevisiae, and the rescue of growth inhibition with exogenous oleate was also observed in C. albicans. In a fluconazole-resistant clinical isolate of C. albicans, a fungicidal effect was produced when fluconazole was combined with 6-NDA. In hyphal growth assays, 6-NDA inhibited the formation of long hyphal filaments in C. albicans. Collectively, our results indicate that the antifungal activity of 6-NDA is mediated by a disruption in fatty acid homeostasis and that 6-NDA has potential utility in the treatment of superficial Candida infections. PMID:22430960

  14. Nitro-Fatty Acids in Plant Signaling: Nitro-Linolenic Acid Induces the Molecular Chaperone Network in Arabidopsis1[OPEN

    PubMed Central

    Padilla, María N.; Begara-Morales, Juan C.; Luque, Francisco; Melguizo, Manuel; Fierro-Risco, Jesús; Peñas-Sanjuán, Antonio; Valderrama, Raquel

    2016-01-01

    Nitro-fatty acids (NO2-FAs) are the product of the reaction between reactive nitrogen species derived of nitric oxide (NO) and unsaturated fatty acids. In animal systems, NO2-FAs are considered novel signaling mediators of cell function based on a proven antiinflammatory response. Nevertheless, the interaction of NO with fatty acids in plant systems has scarcely been studied. Here, we examine the endogenous occurrence of nitro-linolenic acid (NO2-Ln) in Arabidopsis and the modulation of NO2-Ln levels throughout this plant’s development by mass spectrometry. The observed levels of this NO2-FA at picomolar concentrations suggested its role as a signaling effector of cell function. In fact, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO2-Ln was involved in plant defense response against different abiotic-stress conditions, mainly by inducing heat shock proteins and supporting a conserved mechanism of action in both animal and plant defense processes. Bioinformatics analysis revealed that NO2-Ln was also involved in the response to oxidative stress conditions, mainly depicted by H2O2, reactive oxygen species, and oxygen-containing compound responses, with a high induction of ascorbate peroxidase expression. Closely related to these results, NO2-Ln levels significantly rose under several abiotic-stress conditions such as wounding or exposure to salinity, cadmium, and low temperature, thus validating the outcomes found by RNA-seq technology. Jointly, to our knowledge, these are the first results showing the endogenous presence of NO2-Ln in Arabidopsis (Arabidopsis thaliana) and supporting the strong signaling role of these molecules in the defense mechanism against different abiotic-stress situations. PMID:26628746

  15. Antimicrobial peptides incorporating non-natural amino acids as agents for plant protection.

    PubMed

    Ng-Choi, Iteng; Soler, Marta; Güell, Imma; Badosa, Esther; Cabrefiga, Jordi; Bardaji, Eduard; Montesinos, Emilio; Planas, Marta; Feliu, Lidia

    2014-04-01

    The control of plant pathogens is mainly based on copper compounds and antibiotics. However, the use of these compounds has some limitations. They have a high environmental impact and the use of antibiotics is not allowed in several countries. Moreover, resistance has been developed to these pathogens. The identification of new agents able to fight plant pathogenic bacteria and fungi will represent an alternative to currently used antibiotics or pesticides. Antimicrobial peptides are widely recognized as promising candidates, however naturally occurring sequences present drawbacks that limit their development. These include susceptibility to protease degradation and low bioavailability. To overcome these problems, research has focused on the introduction of unnatural amino acids into lead peptide sequences. In particular, we have improved the biological profile of antimicrobial peptides active against plant pathogenic bacteria and fungi by incorporating triazolyl, biaryl and D-amino acids into their sequence. These modifications and their influence on the biological activity are summarized.

  16. Selection of an acid-gas removal process for an LNG plant

    SciTech Connect

    Stone, J.B.; Jones, G.N.; Denton, R.D.

    1996-12-31

    Acid gas contaminants, such as, CO{sub 2}, H{sub 2}S and mercaptans, must be removed to a very low level from a feed natural gas before it is liquefied. CO{sub 2} is typically removed to a level of about 100 ppm to prevent freezing during LNG processing. Sulfur compounds are removed to levels required by the eventual consumer of the gas. Acid-gas removal processes can be broadly classified as: solvent-based, adsorption, cryogenic or physical separation. The advantages and disadvantages of these processes will be discussed along with design and operating considerations. This paper will also discuss the important considerations affecting the choice of the best acid-gas removal process for LNG plants. Some of these considerations are: the remoteness of the LNG plant from the resource; the cost of the feed gas and the economics of minimizing capital expenditures; the ultimate disposition of the acid gas; potential for energy integration; and the composition, including LPG and conditions of the feed gas. The example of the selection of the acid-gas removal process for an LNG plant.

  17. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    PubMed Central

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  18. Naturally occurring radioactive material (NORM) from a former phosphoric acid processing plant.

    PubMed

    Beddow, H; Black, S; Read, D

    2006-01-01

    In recent years there has been an increasing awareness of the radiological impact of non-nuclear industries that extract and/or process ores and minerals containing naturally occurring radioactive material (NORM). These industrial activities may result in significant radioactive contamination of (by-) products, wastes and plant installations. In this study, scale samples were collected from a decommissioned phosphoric acid processing plant. To determine the nature and concentration of NORM retained in pipe-work and associated process plant, four main areas of the site were investigated: (1) the 'Green Acid Plant', where crude acid was concentrated; (2) the green acid storage tanks; (3) the Purified White Acid (PWA) plant, where inorganic impurities were removed; and (4) the solid waste, disposed of on-site as landfill. The scale samples predominantly comprise the following: fluorides (e.g. ralstonite); calcium sulphate (e.g. gypsum); and an assemblage of mixed fluorides and phosphates (e.g. iron fluoride hydrate, calcium phosphate), respectively. The radioactive inventory is dominated by 238U and its decay chain products, and significant fractionation along the series occurs. Compared to the feedstock ore, elevated concentrations (< or =8.8 Bq/g) of 238U were found to be retained in installations where the process stream was rich in fluorides and phosphates. In addition, enriched levels (< or =11 Bq/g) of 226Ra were found in association with precipitates of calcium sulphate. Water extraction tests indicate that many of the scales and waste contain significantly soluble materials and readily release radioactivity into solution.

  19. Effects of acid precipitation on reproduction in alpine plant species. [Erythronium grandiflorum; Aquilegia caerulea

    SciTech Connect

    McKenna, M.A.; Hille-Salgueiro, M.; Musselman, R.C. Dept. of Agriculture, Fort Collins, CO )

    1990-01-01

    A series of experiments were designed to determine the impact of acid rain on plant reproductive processes, a critical component of a species life history. Research was carried out in herbaceous alpine communities at the USDA (United States Department of Agriculture) Forest Service Glacier Lakes Ecosystem Experiments Site in the Snowy Mts. of Wyoming. A range of species were surveyed to monitor the sensitivity of pollen to acidification during germination and growth, and all species demonstrated reduced in vitro pollen germination in acidified media. Field pollinations were carried out in Erythronium grandiflorum and Aquilegia caerulea to determine the reproductive success of plants exposed to simulated ambient precipitation (pH 5.6) or simulated acid precipitation (pH 3.6) prior to pollination. In Erythronium, no differences were observed in seed set and seed weight of fruits resulting from the two pollination treatments. In Aquilegia, fruits resulting from the acid spray treatment produced fewer seeds and lighter seeds.

  20. Pseudometallophytes colonising Pb/Zn mine tailings: a description of the plant-microorganism-rhizosphere soil system and isolation of metal-tolerant bacteria.

    PubMed

    Becerra-Castro, C; Monterroso, C; Prieto-Fernández, A; Rodríguez-Lamas, L; Loureiro-Viñas, M; Acea, M J; Kidd, P S

    2012-05-30

    The plant-microorganism-soil system of three pseudometallophytes (Betula celtiberica, Cytisus scoparius and Festuca rubra) growing in a Pb/Zn mine was characterised. Plant metal accumulation, soil metal fractions (rhizosphere and non-vegetated) and bacterial densities were determined. Total Cd, Pb and Zn in non-vegetated soils was up to 50, 3000 and 20,000 mg kg(-1) dry weight, respectively. The residual fraction dominated non-vegetated soils, whereas plant-available fractions became important in rhizosphere soils. All plant species effectively excluded metals from the shoot. F. rubra presented a shoot:root transport factor of ≤0.2 and this population could be useful in future phytostabilisation trials. Culturable bacterial densities and diversity were low (predominantly Actinobacteria). Rhizosphere soils hosted higher total and metal-tolerant bacterial densities. Seventy-four metal-tolerant rhizobacteria were isolated, and characterised genotypically (BOX-PCR, 16S rDNA) and phenotypically [Cd/Zn tolerance, biosurfactant production and plant growth promoting (PGP) traits]. Several isolates resisted high concentrations of Cd and Zn, and only a few presented PGP traits. Fourteen isolates were evaluated for promoting plant growth of two species (Salix viminalis and Festuca pratensis). Thirteen inoculants enhanced growth of F. pratensis, while only three enhanced growth of S. viminalis. Growth enhancement could not always be related to isolate PGP traits. In conclusion, some isolates show potential application in phytostabilisation or phytoextraction techniques.

  1. Distribution of eastern equine encephalomyelitis viral protein and nucleic acid within central nervous tissue lesions in white-tailed deer (Odocoileus virginianus).

    PubMed

    Kiupel, M; Fitzgerald, S D; Pennick, K E; Cooley, T M; O'Brien, D J; Bolin, S R; Maes, R K; Del Piero, F

    2013-11-01

    An outbreak of eastern equine encephalomyelitis (EEE) occurred in Michigan free-ranging white-tailed deer (Odocoileus virginianus) during late summer and fall of 2005. Brain tissue from 7 deer with EEE, as confirmed by reverse transcriptase polymerase chain reaction, was studied. Detailed microscopic examination, indirect immunohistochemistry (IHC), and in situ hybridization (ISH) were used to characterize the lesions and distribution of the EEE virus within the brain. The main lesion in all 7 deer was a polioencephalomyelitis with leptomeningitis, which was more prominent within the cerebral cortex, thalamus, hypothalamus, and brainstem. In 3 deer, multifocal microhemorrhages surrounded smaller vessels with or without perivascular cuffing, although vasculitis was not observed. Neuronal necrosis, associated with perineuronal satellitosis and neutrophilic neuronophagia, was most prominent in the thalamus and the brainstem. Positive IHC labeling was mainly observed in the perikaryon, axons, and dendrites of necrotic and intact neurons and, to a much lesser degree, in glial cells, a few neutrophils in the thalamus and the brainstem, and occasionally the cerebral cortex of the 7 deer. There was minimal IHC-based labeling in the cerebellum and hippocampus. ISH labeling was exclusively observed in the cytoplasm of neurons, with a distribution similar to IHC-positive neurons. Neurons positive by IHC and ISH were most prominent in the thalamus and brainstem. The neuropathology of EEE in deer is compared with other species. Based on our findings, EEE has to be considered a differential diagnosis for neurologic disease and meningoencephalitis in white-tailed deer.

  2. The Tail of BPM

    NASA Astrophysics Data System (ADS)

    Kruba, Steve; Meyer, Jim

    Business process management suites (BPMS's) represent one of the fastest growing segments in the software industry as organizations automate their key business processes. As this market matures, it is interesting to compare it to Chris Anderson's 'Long Tail.' Although the 2004 "Long Tail" article in Wired magazine was primarily about the media and entertainment industries, it has since been applied (and perhaps misapplied) to other markets. Analysts describe a "Tail of BPM" market that is, perhaps, several times larger than the traditional BPMS product market. This paper will draw comparisons between the concepts in Anderson's article (and subsequent book) and the BPM solutions market.

  3. Estimating tail probabilities

    SciTech Connect

    Carr, D.B.; Tolley, H.D.

    1982-12-01

    This paper investigates procedures for univariate nonparametric estimation of tail probabilities. Extrapolated values for tail probabilities beyond the data are also obtained based on the shape of the density in the tail. Several estimators which use exponential weighting are described. These are compared in a Monte Carlo study to nonweighted estimators, to the empirical cdf, to an integrated kernel, to a Fourier series estimate, to a penalized likelihood estimate and a maximum likelihood estimate. Selected weighted estimators are shown to compare favorably to many of these standard estimators for the sampling distributions investigated.

  4. Lipid and fatty acid composition of muga silkworm, Antheraea assama, host plants in relation to silkworm growth.

    PubMed

    Unni, B G; Kakoty, A C; Khanikor, D; Bhattacharya, P R; Pathak, M G; Pillai, K; Pillai, R; Choudhury, A; Saikia, P C; Ghosh, A C

    1996-05-01

    The lipid and fatty acid composition of the leaves (tender, medium and mature) of muga host plants, Machilus bombycina, Litsaea monopetala (primary food plants) and L. cubeba and L. salicifolia (family: Lauraceae) (secondary food plants) was investigated by standard procedures, gas chromatography after saponification and esterification. The total lipid content of M. bombycina and L. monopetala leaves was recorded to be higher (16 and 18 g%), respectively, than that of L. cubeba (10 g%) and L. salicifolia (12 g%). GC analysis identified the presence of eight fatty acids (C14 to C22) and the concentration varied from 0.0297 to 8.1572 g% dry leaf powder. Among the fatty acids, (C14 to C22), polyunsaturated fatty acids were recorded to be highest in concentration in mature leaves of the primary host plants. The concentrations of saturated and polyunsatuated fatty acids were found to be at a minimum level in all the types of leaves of secondary muga host plants.

  5. Plant Hormone Salicylic Acid Produced by a Malaria Parasite Controls Host Immunity and Cerebral Malaria Outcome.

    PubMed

    Matsubara, Ryuma; Aonuma, Hiroka; Kojima, Mikiko; Tahara, Michiru; Andrabi, Syed Bilal Ahmad; Sakakibara, Hitoshi; Nagamune, Kisaburo

    2015-01-01

    The apicomplexan parasite Toxoplasma gondii produces the plant hormone abscisic acid, but it is unclear if phytohormones are produced by the malaria parasite Plasmodium spp., the most important parasite of this phylum. Here, we report detection of salicylic acid, an immune-related phytohormone of land plants, in P. berghei ANKA and T. gondii cell lysates. However, addition of salicylic acid to P. falciparum and T. gondii culture had no effect. We transfected P. falciparum 3D7 with the nahG gene, which encodes a salicylic acid-degrading enzyme isolated from plant-infecting Pseudomonas sp., and established a salicylic acid-deficient mutant. The mutant had a significantly decreased concentration of parasite-synthesized prostaglandin E2, which potentially modulates host immunity as an adaptive evolution of Plasmodium spp. To investigate the function of salicylic acid and prostaglandin E2 on host immunity, we established P. berghei ANKA mutants expressing nahG. C57BL/6 mice infected with nahG transfectants developed enhanced cerebral malaria, as assessed by Evans blue leakage and brain histological observation. The nahG-transfectant also significantly increased the mortality rate of mice. Prostaglandin E2 reduced the brain symptoms by induction of T helper-2 cytokines. As expected, T helper-1 cytokines including interferon-γ and interleukin-2 were significantly elevated by infection with the nahG transfectant. Thus, salicylic acid of Plasmodium spp. may be a new pathogenic factor of this threatening parasite and may modulate immune function via parasite-produced prostaglandin E2.

  6. Wagging tail vibration absorber

    NASA Technical Reports Server (NTRS)

    Barclay, R. G.; Humphrey, P. W.

    1969-01-01

    A 750-foot cantilever length of extendible-tape boom (very low stiffness) was considered as the main system to be damped. A number of tail lengths were tried from 20 feet to 80 feet after which 40 feet was investigated further as a desirable compromise between performance and practical lengths. A 40-foot damping tail produced a damping effect on the main boom for the first mode equivalent in decay rate to 3.1 percent of critical damping. In this case the spring-hinge and tail were tuned to the main boom first mode frequency and the hinge damping was set at 30 percent of critical based on the tail properties. With this same setting, damping of the second mode was .4 percent and the third mode .1 percent.

  7. [Rapid determination of eight organic acids in plant tissue by sequential extraction and high performance liquid chromatography].

    PubMed

    Huang, Tianzhi; Wang, Shijie; Liu Xiuming; Liu, Hong; Wu, Yanyou; Luo Xuqiang

    2014-12-01

    A sequential extraction method was developed to determine different forms of oxalate and seven oxalate-metabolism-related organic acids (glyoxylic acid, tartaric acid, glycolic acid, malic acid, acetic acid, citric acid, succinic acid) in plant tissue. The ultra-pure water was used as the extraction medium to obtain water-soluble oxalic acid and the other seven water-soluble organic acids. After the extraction of the water-soluble organic acids, the residues were extracted by dilute hydrochloric acid successively to get the acid-soluble oxalate which entered the liquid phase. A Hypersil ODS column was used with 5 mmol/L potassium dihydrogen phosphate buffer solution (pH 2. 8) as the mobile phase. The diode array detector was set at 210 nm and the column temperature at 30 °C with the injection volume of 5 µL. The flow rate was controlled at different times which allowed a good and rapid separation of the organic acids and hydrochloric acid. Under these conditions, the linear ranges of the method were 1-2000 mg/L for oxalic acid, 25-2,000 mg/L for acetic acid, and 10-2,000 mg/L for glyoxylic acid, tartaric acid, glycolic acid, malic acid, citric acid and succinic acid, with the correlation coefficients of the eight organic acids ≥ 0. 9996. The average recoveries of the eight organic acids in leaves and roots were 93. 5%-104. 4% and 85. 3%-105. 4% with RSDs of 0. 15% -2.43% and 0. 31%-2. 9% (n=7), respectively. The limits of detection ranged from 1 to 10 ng (S/N=3). The results indicated that the method is accurate, rapid and reproducible for the determination of organic acids in plant samples.

  8. Uranium mill tailings neutralization: contaminant complexation and tailings leaching studies

    SciTech Connect

    Opitz, B.E.; Dodson, M.E.; Serne, R.J.

    1985-05-01

    Laboratory experiments were performed to compare the effectiveness of limestone (CaCO/sub 3/) and hydrated lime (Ca(OH)/sub 2/) for improving waste water quality through the neutralization of acidic uranium mill tailings liquor. The experiments were designed to also assess the effects of three proposed mechanisms - carbonate complexation, elevated pH, and colloidal particle adsorption - on the solubility of toxic contaminants found in a typical uranium mill waste solution. Of special interest were the effects each of these possible mechanisms had on the solution concentrations of trace metals such as Cd, Co, Mo, Zn, and U after neutralization. Results indicated that the neutralization of acidic tailings to a pH of 7.3 using hydrated lime provided the highest overall waste water quality. Both the presence of a carbonate source or elevating solution pH beyond pH = 7.3 resulted in a lowering of previously achieved water quality, while adsorption of contaminants onto colloidal particles was not found to affect the solution concentration of any constituent investigated. 24 refs., 8 figs., 19 tabs.

  9. Functional analyses of carnivorous plant-specific amino acid residues in S-like ribonucleases.

    PubMed

    Arai, Naoki; Nishimura, Emi; Kikuchi, Yo; Ohyama, Takashi

    2015-09-11

    Unlike plants with no carnivory, carnivorous plants seem to use S-like ribonucleases (RNases) as an enzyme for carnivory. Carnivorous plant-specific conserved amino acid residues are present at four positions around the conserved active site (CAS). The roles of these conserved amino acid residues in the enzymatic function were explored in the current study by preparing five recombinant variants of DA-I, the S-like RNase of Drosera adelae. The kcat and kcat/Km values of the enzymes revealed that among the four variants with a single mutation, the serine to glycine mutation at position 111 most negatively influenced the enzymatic activity. The change in the bulkiness of the amino acid residue side-chain seemed to be the major cause of the above effect. Modeling of the three dimensional (3D) structures strongly suggested that the S to G mutation at 111 greatly altered the overall enzyme conformation. The conserved four amino acid residues are likely to function in keeping the two histidine residues, which are essential for the cleavage of RNA strands, and the CAS in the most functional enzymatic conformation.

  10. Identification and biochemical characterization of plant acylamino acid-releasing enzyme.

    PubMed

    Yamauchi, Yasuo; Ejiri, Yukinori; Toyoda, Yasuyuki; Tanaka, Kiyoshi

    2003-08-01

    Plant acylamino acid-releasing enzyme (AARE) catalyzing the N-terminal hydrolysis of N(alpha)-acylpeptides to release N(alpha)-acylated amino acids, was biochemically characterized using recombinant and native AAREs. A cDNA encoding a deduced Arabidopsis thaliana AARE (AtAARE) was cloned and sequenced. The deduced amino acid sequence encoded a 764 amino acid protein of 83.9 kDa, which was 31.8% identical with that of rat AARE. In particular, the proposed catalytic residues (Ser, Asp, and His) of AARE, called the "catalytic triad residues, " were completely conserved. Recombinant AtAARE was expressed in Escherichia coli and confirmed to be a functional AARE. Native AAREs were prepared from A. thaliana and cucumber (Cucumis sativus, L.) plants. Both native AAREs were tetrameric proteins of 350 kDa comprising four subunits of 82 kDa, and showed typical enzymological properties of other AAREs, i.e. sensitivity to diisopropyl fluorophosphate, an optimum pH of around 7.0, and an optimum temperature of 37 degrees C. Both the native and recombinant AAREs were immunochemically homologous. Intracelluar fractionation analysis showed that the AARE was mainly present in the stroma of chloroplasts. Native AARE degraded the glycated ribulose-1,5-bisphoshate carboxylase/oxygenase protein but not the native protein. Thus, plant AARE might be involved in not only catalysis of the N-terminal hydrolysis of N(alpha)-acylpeptides but also the elimination of glycated proteins.

  11. Characteristics of dioxin emissions from a Waelz plant with acid and basic kiln mode.

    PubMed

    Hung, Pao Chen; Chi, Kai Hsien; Chen, Mei Lien; Chang, Moo Been

    2012-01-30

    The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in the flue gas of a Waelz plant operated in acid and basic modes, respectively. To abate (PCDD/F) and other pollutants, the plant operates with a post-treatment of flue gases by activated carbon injection and subsequent filtration. Relatively high PCDD/F discharge by fly ashes is found with acid kiln mode of the Waelz process. Therefore, basic kiln mode of the Waelz process is investigated and compared in this plant. With the adsorbent injection rate of 7 kg/h (95 mg/Nm(3)), the PCDD/F concentration in stack gas was measured as 0.123 ng I-TEQ/Nm(3) in the basic operating mode. The added Ca(OH)(2) reacted with metal catalysts and HCl((g)) in the flue gas and thus effectively suppressed the formation of PCDD/Fs. PCDD/F concentrations in fly ashes sampled from the dust settling chamber, cyclone, primary filter and secondary filter in basic kiln mode were significantly lower than that in acid kiln mode. Total PCDD/F emission on the basis of treating one kg of electric arc furnace dust in the basic operation mode was 269 ng I-TEQ/kg EAF-dust treated which was significantly lower than that in acid mode (640 ng I-TEQ/kg EAF-dust treated).

  12. The Tail Suspension Test

    PubMed Central

    Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

    2012-01-01

    The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test. PMID:22315011

  13. Effects of acid rain, alone and in combination with gaseous pollutants, on growth and yield of crop plants

    SciTech Connect

    Shriner, D.S.; Johnston, J.W. Jr.

    1985-01-01

    Greenhouse, growth chamber, and field experiments were conducted to determine the response of crop plants to levels of acidity in simulated rain. The major objectives were: to determine the levels of acidity in rain that alter crop productivity; to evaluate varietal differences in crop response; and to determine the response of crop plants to the combined stress of acid rain and gaseous pollutants, primarily ozone. Results showed additive effects rather than synergistic ones.

  14. Defense signaling among interconnected ramets of a rhizomatous clonal plant, induced by jasmonic-acid application

    NASA Astrophysics Data System (ADS)

    Chen, Jin-Song; Lei, Ning-Fei; Liu, Qing

    2011-07-01

    Resource sharing between ramets of clonal plants is a well-known phenomenon that allows stoloniferous and rhizomatous species to internally transport water, mineral nutrients and carbohydrates from sites of high supply to sites of high demand. Moreover, vascular ramet connections are likely to provide an excellent means to share substances other than resources, such as defense signals. In a greenhouse experiment, the rhizomatous sedge Carex alrofusca, consisting of integrated ramets of different ages, was used to study the transmission of defense signals through belowground rhizome connections in response to local spray with jasmonic-acid. A feeding preference test with the caterpillar Gynaephora rnenyuanensis was employed to assess benefits of rhizome connections on defense signaling. Young ramets were more responsive to jasmonic-acid treatment than middle-aged or old ramets. Condensed tannin content in the foliage of young ramets showed a significant increase and soluble carbohydrate and nitrogen content showed marginally significant decreases in the 1 mM jasmonic-acid treatment but not in control and/or 0.0001 mM jasmonic-acid treatments. The caterpillar G. rnenyuanensis preferentially grazed young ramets. After a localized spray of 1 mM jasmonic-acid, the leaf area of young ramets consumed by herbivores was greatly reduced. We propose that defense signals may be transmitted through physical connections (stolon or rhizome) among interconnected ramets of clonal plants. Induced resistance to herbivory may selectively enhance the protection of more vulnerable and valuable plant tissues and confer a significant benefit to clonal plants by a modular risk-spreading strategy, equalizing ontogenetic differences of unevenly-aged ramets in chemical defense compounds and nutritional properties of tissue.

  15. 1-aminocyclopropane-1-carboxylic acid (ACC) in plants: more than just the precursor of ethylene!

    PubMed Central

    Van de Poel, Bram; Van Der Straeten, Dominique

    2014-01-01

    Ethylene is a simple two carbon atom molecule with profound effects on plants. There are quite a few review papers covering all aspects of ethylene biology in plants, including its biosynthesis, signaling and physiology. This is merely a logical consequence of the fascinating and pleiotropic nature of this gaseous plant hormone. Its biochemical precursor, 1-aminocyclopropane-1-carboxylic acid (ACC) is also a fairly simple molecule, but perhaps its role in plant biology is seriously underestimated. This triangularly shaped amino acid has many more features than just being the precursor of the lead-role player ethylene. For example, ACC can be conjugated to three different derivatives, but their biological role remains vague. ACC can also be metabolized by bacteria using ACC-deaminase, favoring plant growth and lowering stress susceptibility. ACC is also subjected to a sophisticated transport mechanism to ensure local and long-distance ethylene responses. Last but not least, there are now a few exciting studies where ACC has been reported to function as a signal itself, independently from ethylene. This review puts ACC in the spotlight, not to give it the lead-role, but to create a picture of the stunning co-production of the hormone and its precursor. PMID:25426135

  16. An eco-balance of a recycling plant for spent lead-acid batteries.

    PubMed

    Salomone, Roberta; Mondello, Fabio; Lanuzza, Francesco; Micali, Giuseppe

    2005-02-01

    This study applies Life Cycle Assessment (LCA) methodology to present an eco-balance of a recycling plant that treats spent lead-acid batteries. The recycling plant uses pyrometallurgical treatment to obtain lead from spent batteries. The application of LCA methodology (ISO 14040 series) enabled us to assess the potential environmental impacts arising from the recycling plant's operations. Thus, net emissions of greenhouse gases as well as other major environmental consequences were examined and hot spots inside the recycling plant were identified. A sensitivity analysis was also performed on certain variables to evaluate their effect on the LCA study. The LCA of a recycling plant for spent lead-acid batteries presented shows that this methodology allows all of the major environmental consequences associated with lead recycling using the pyrometallurgical process to be examined. The study highlights areas in which environmental improvements are easily achievable by a business, providing a basis for suggestions to minimize the environmental impact of its production phases, improving process and company performance in environmental terms.

  17. Nucleic acids encoding plant glutamine phenylpyruvate transaminase (GPT) and uses thereof

    DOEpatents

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-03-29

    Glutamine phenylpyruvate transaminase (GPT) proteins, nucleic acid molecules encoding GPT proteins, and uses thereof are disclosed. Provided herein are various GPT proteins and GPT gene coding sequences isolated from a number of plant species. As disclosed herein, GPT proteins share remarkable structural similarity within plant species, and are active in catalyzing the synthesis of 2-hydroxy-5-oxoproline (2-oxoglutaramate), a powerful signal metabolite which regulates the function of a large number of genes involved in the photosynthesis apparatus, carbon fixation and nitrogen metabolism.

  18. Enhanced rosmarinic acid production in cultured plants of two species of Mentha.

    PubMed

    Roy, Debleena; Mukhopadhyay, Sandip

    2012-11-01

    In the present investigation an attempt has been made to enhance rosmarinic acid level in plants, grown in vitro, of 2 species of Mentha in presence of 2 precursors in the nutrient media during culture. For in vitro culture establishment and shoot bud multiplication, MS basal media were used supplemented with different concentrations and combinations of different growth regulator like NAA (alpha-napthaleneacetic acid), BAP (6-benzylaminopurine). The medium containing NAA (0.25 mg/L) and BAP (2.5 mg/L) gave the highest potentiality of shoot formation (average 58.0 numbers of shoots) per explant for Mentha piperita L. and the medium containing BAP (2.0 mg/L) gave the highest potentiality of shoot (average 19.2 numbers of shoots) formation per explant for Mentha arvensis L. The complete plants were regenerated in above mentioned media after 8 weeks of subculture. For in vitro enhancement of rosmarinic acid production, the 2 precursors tyrosine (Tyr) and phenylalanine (Phe) were added in the nutrient media at different levels (0.5 mg/L to 15.0 mg/L). Tyrosine was found to be very effective for augmenting rosmarinic acid content in Mentha piperita L. It nearly increased the production up to 1.77 times. In case of Mentha arvensis L., phenylalanine significantly affected the production of rosmarinic acid and the production was nearly 2.03 times more than the control. No significant increase in biomass was observed after addition of these precursors indicating that the added amino acids acting as precursors for rosmarinic acid synthesis were readily utilized in producing rosmarinic acid without promoting growth. Total protein profile also revealed the presence of a specific band in polyacrylamide gel electrophoresis.

  19. Expression of a cyanobacterial {del}{sup 6}-desaturase gene results in {gamma}-linolenic acid production in transgenic plants

    SciTech Connect

    Reddy, A.S.; Thomas, T.L.

    1996-05-01

    Gamma-linolenic acid (GLA), a nutritionally important fatty acid in human and animal diets, is not produced in oil seed crops. Many oil seed plants, however, produce significant quantities of linoleic acid, a fatty acid that could be converted to GLA by the enzyme {del}{sup 6}-desaturase if it were present. As a first step to producing GLA in oil seed crops, we have cloned a cyanobacterial {del}{sup 6}-desaturase gene. Expression of this gene in transgenic tobacco resulted in GLA accumulation. Octadecatetraenoic acid, a highly unsaturated, industrially important fatty acid, was also found in transgenic tobacco plants expressing the cyanobacterial {del}{sup 6}-desaturase. This is the first example of engineering the production of `novel` polyunsaturated fatty acids in transgenic plants. 28 refs., 4 figs., 1 tab.

  20. Rapid and efficient isolation of high quality nucleic acids from plant tissues rich in polyphenols and polysaccharides.

    PubMed

    Japelaghi, Reza Heidari; Haddad, Raheem; Garoosi, Ghasem-Ali

    2011-10-01

    Isolation of high quality nucleic acids from plant tissues rich in polysaccharides and polyphenols is often difficult. The presence of these substances can affect the quality and/or quantity of the nucleic acids isolated. Here, we describe a rapid and efficient nucleic acids extraction protocol that in contrast to other methods tested, effectively purify high quality nucleic acids from plant tissues rich in polysaccharides and polyphenolic compounds such as different grape tissues and fruit tissue of fruit trees. The nucleic acids isolated with this protocol were successfully used for many functional genomic based experiments including polymerase chain reaction, reverse transcription polymerase chain reaction (RT-PCR), cloning, and semiquantitative RT-PCR.

  1. Ecological restoration alters microbial communities in mine tailings profiles

    PubMed Central

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-01-01

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0–30 cm soils and altered the bacterial communities at 0–20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30–60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0–20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings. PMID:27126064

  2. Ecological restoration alters microbial communities in mine tailings profiles.

    PubMed

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-29

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0-30 cm soils and altered the bacterial communities at 0-20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30-60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0-20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  3. Ecological restoration alters microbial communities in mine tailings profiles

    NASA Astrophysics Data System (ADS)

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-01

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0–30 cm soils and altered the bacterial communities at 0–20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30–60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0–20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  4. Electrodialytic remediation of suspended mine tailings.

    PubMed

    Hansen, Henrik K; Rojo, Adrian; Pino, Denisse; Ottosen, Lisbeth M; Ribeiro, Alexandra B

    2008-07-01

    This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings applying 40 mA during 7 days. The liquid-to-solid ratios used were 3, 6 and 9 mL g(- 1). With addition of sulfuric acid, the process was enhanced because the pH decreased to either 2 or 4, and copper was therefore dissolved. The maximum copper removal was 80% with addition of sulfuric acid in 7-day experiment at 40 mA, with approximately 137.5 g mine tailings on dry basis. The removal for a static (baseline) experiment only amounted 15% when passing approximately the same amount of charge through 130 g of mine tailings. The use of air bubbling to keep the tailings suspended increased the removal efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation.

  5. Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

  6. 78 FR 15753 - Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... COMMISSION Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power..., DG-1269 ``Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear... lead-acid storage batteries in nuclear power plants. DATES: Submit comments by May 13, 2013....

  7. 78 FR 58574 - Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-24

    ... COMMISSION Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power..., Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants.'' The guide... with regard to the maintenance, testing, and replacement of vented lead-acid storage batteries...

  8. Theroa zethus Caterpillars Use Acid Secretion of Anti-Predator Gland to Deactivate Plant Defense.

    PubMed

    Dussourd, David E

    2015-01-01

    In North America, notodontid caterpillars feed almost exclusively on hardwood trees. One notable exception, Theroa zethus feeds instead on herbaceous plants in the Euphorbiaceae protected by laticifers. These elongate canals follow leaf veins and contain latex under pressure; rupture causes the immediate release of sticky poisonous exudate. T. zethus larvae deactivate the latex defense of poinsettia and other euphorbs by applying acid from their ventral eversible gland, thereby creating furrows in the veins. The acid secretion softens the veins allowing larvae to compress even large veins with their mandibles and to disrupt laticifers internally often without contacting latex. Acid secretion collected from caterpillars and applied to the vein surface sufficed to create a furrow and to reduce latex exudation distal to the furrow where T. zethus larvae invariably feed. Larvae with their ventral eversible gland blocked were unable to create furrows and suffered reduced growth on poinsettia. The ventral eversible gland in T. zethus and other notodontids ordinarily serves to deter predators; when threatened, larvae spray acid from the gland orifice located between the mouthparts and first pair of legs. To my knowledge, T. zethus is the first caterpillar found to use an antipredator gland for disabling plant defenses. The novel combination of acid application and vein constriction allows T. zethus to exploit its unusual latex-bearing hosts.

  9. The role of 5-aminolevulinic acid in the response to cold stress in soybean plants.

    PubMed

    Balestrasse, Karina B; Tomaro, María L; Batlle, Alcira; Noriega, Guillermo O

    2010-12-01

    In this study, the possibility of enhancing cold stress tolerance of soybean plants (Glycine max L.) by exogenous application of 5-aminolevulinic acid (ALA) was investigated. ALA was added to the Hoagland solution at various concentrations ranging from 0 to 40 μM for 12 h. After ALA treatment, the plants were subjected to cold stress at 4°C for 48 h. ALA at low concentrations (5-10 μM) provided significant protection against cold stress compared to non-ALA-treated plants, enhancing chlorophyll content (Chl) as well as relative water content (RWC). Increase of thiobarbituric acid reactive species (TBARS) levels was also prevented, whereas exposure to higher ALA concentrations (15-40 μM) brought about a dose dependent increase of these species, reaching a maximum of 117% in plants pre-treated with 40 μM ALA compared to controls. ALA pre-treatment also enhanced catalase (CAT) and heme oxygenase-1 (HO-1) activities. These findings indicate that HO-1 acts not only as the rate limiting enzyme in heme catabolism, but also as an antioxidant enzyme. The highest cold tolerance was obtained with 5 μM ALA pre-treatment. Results show that ALA, which is considered as an endogenous plant growth regulator, could be used effectively to protect soybean plants from the damaging effects of cold stress by enhancing the activity of heme proteins, e.g., catalase (CAT) and by promoting heme catabolism leading to the production of the highly antioxidant biliverdin and carbon monoxide, without any adverse effect on the plant growth.

  10. A fatty acid glycoside from a marine-derived fungus isolated from mangrove plant Scyphiphora hydrophyllacea.

    PubMed

    Zeng, Yan-Bo; Wang, Hui; Zuo, Wen-Jian; Zheng, Bo; Yang, Tao; Dai, Hao-Fu; Mei, Wen-Li

    2012-03-01

    To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic acid methylester-3-O-α-l-rhamnopyranoside (1) by spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY and HMBC) and chemical methods. Antimicrobial assay showed compound 1 possessed modest inhibitory effect on Saphylococcus aureus and methicillin-resistant S. aureus (MRSA) using the filter paper disc agar diffusion method.

  11. Salicylic acid negatively affects the response to salt stress in pea plants.

    PubMed

    Barba-Espín, G; Clemente-Moreno, M J; Alvarez, S; García-Legaz, M F; Hernández, J A; Díaz-Vivancos, P

    2011-11-01

    We studied the effect of salicylic acid (SA) treatment on the response of pea plants to salinity. Sodium chloride (NaCl)-induced damage to leaves was increased by SA, which was correlated with a reduction in plant growth. The content of reduced ascorbate and glutathione in leaves of salt-treated plants increased in response to SA, although accumulation of the respective oxidised forms occurred. An increase in hydrogen peroxide also occurred in leaves of salt-exposed plants treated with SA. In the absence of NaCl, SA increased ascorbate peroxidase (APX; 100 μm) and glutathione-S transferase (GST; 50 μm) activities and increased catalase (CAT) activity in a concentration-dependent manner. Salinity decreased glutathione reductase (GR) activity, but increased GST and CAT activity. In salt-stressed plants, SA also produced changes in antioxidative enzymes: 100 μm SA decreased APX but increased GST. Finally, a concentration-dependent increase in superoxide dismutase (SOD) activity was induced by SA treatment in salt-stressed plants. Induction of PR-1b was observed in NaCl-stressed plants treated with SA. The treatment with SA, as well as the interaction between salinity and SA treatment, had a significant effect on PsMAPK3 expression. The expression of PsMAPK3 was not altered by 70 mm NaCl, but was statistically higher in the absence than in the presence of SA. Overall, the results show that SA treatment negatively affected the response of pea plants to NaCl, and this response correlated with an imbalance in antioxidant metabolism. The data also show that SA treatment could enhance the resistance of salt-stressed plants to possible opportunistic pathogen attack, as suggested by increased PR-1b gene expression.

  12. Principal transcriptional regulation and genome-wide system interactions of the Asp-family and aromatic amino acid networks of amino acid metabolism in plants.

    PubMed

    Less, Hadar; Angelovici, Ruthie; Tzin, Vered; Galili, Gad

    2010-10-01

    Amino acid metabolism is among the most important and best recognized networks within biological systems. In plants, amino acids serve multiple functions associated with growth. Besides their function in protein synthesis, the amino acids are also catabolized into energy-associated metabolites as well we into numerous secondary metabolites, which are essential for plant growth and response to various stresses. Despite the central importance of amino acids in plants growth, elucidation of the regulation of amino acid metabolism within the context of the entire system, particularly transcriptional regulation, is still in its infancy. The different amino acids are synthesized by a number of distinct metabolic networks, which are expected to possess regulatory cross interactions between them for proper coordination of their interactive functions, such as incorporation into proteins. Yet, individual amino acid metabolic networks are also expected to differentially cross interact with various genome-wide gene expression programs and metabolic networks, in respect to their functions as precursors for various metabolites with distinct functions. In the present review, we discuss our recent genomics, metabolic and bioinformatics studies, which were aimed at addressing these questions, focusing mainly on the Asp-family metabolic network as the main example and also comparing it to the aromatic amino acids metabolic network as a second example (Angelovici et al. in Plant Physiol 151:2058-2072, 2009; Less and Galili in BMC Syst Biol 3:14, 2009; Tzin et al. in Plant J 60:156-167, 2009). Our focus on these two networks is because of the followings: (i) both networks are central to plant metabolism and growth and are also precursors for a wide range of primary and secondary metabolites that are indispensable to plant growth; (ii) the amino acids produced by these two networks are also essential to the nutrition and health of human and farm animals; and (iii) both networks contain

  13. Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

    PubMed

    Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

    2016-02-20

    In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed.

  14. Amino acid sequences of heterotrophic and photosynthetic ferredoxins from the tomato plant (Lycopersicon esculentum Mill.).

    PubMed

    Kamide, K; Sakai, H; Aoki, K; Sanada, Y; Wada, K; Green, L S; Yee, B C; Buchanan, B B

    1995-11-01

    Several forms (isoproteins) of ferredoxin in roots, leaves, and green and red pericarps in tomato plants (Lycopersicon esculentum Mill.) were earlier identified on the basis of N-terminal amino acid sequence and chromatographic behavior (Green et al. 1991). In the present study, a large scale preparation made possible determination of the full length amino acid sequence of the two ferredoxins from leaves. The ferredoxins characteristic of fruit and root were sequenced from the amino terminus to the 30th residue or beyond. The leaf ferredoxins were confirmed to be expressed in pericarp of both green and red fruit. The ferredoxins characteristic of fruit and root appeared to be restricted to those tissue. The results extend earlier findings in demonstrating that ferredoxin occurs in the major organs of the tomato plant where it appears to function irrespective of photosynthetic competence.

  15. Plastidic aspartate aminotransferases and the biosynthesis of essential amino acids in plants.

    PubMed

    de la Torre, Fernando; Cañas, Rafael A; Pascual, M Belén; Avila, Concepción; Cánovas, Francisco M

    2014-10-01

    In the chloroplasts and in non-green plastids of plants, aspartate is the precursor for the biosynthesis of different amino acids and derived metabolites that play distinct and important roles in plant growth, reproduction, development or defence. Aspartate biosynthesis is mediated by the enzyme aspartate aminotransferase (EC 2.6.1.1), which catalyses the reversible transamination between glutamate and oxaloacetate to generate aspartate and 2-oxoglutarate. Plastids contain two aspartate aminotransferases: a eukaryotic-type and a prokaryotic-type bifunctional enzyme displaying aspartate and prephenate aminotransferase activities. A general overview of the biochemistry, regulation, functional significance, and phylogenetic origin of both enzymes is presented. The roles of these plastidic aminotransferases in the biosynthesis of essential amino acids are discussed.

  16. Salicylic acid beyond defence: its role in plant growth and development.

    PubMed

    Rivas-San Vicente, Mariana; Plasencia, Javier

    2011-06-01

    In recent years salicylic acid (SA) has been the focus of intensive research due to its function as an endogenous signal mediating local and systemic plant defence responses against pathogens. It has also been found that SA plays a role during the plant response to abiotic stresses such as drought, chilling, heavy metal toxicity, heat, and osmotic stress. In this sense, SA appears to be, just like in mammals, an 'effective therapeutic agent' for plants. Besides this function during biotic and abiotic stress, SA plays a crucial role in the regulation of physiological and biochemical processes during the entire lifespan of the plant. The discovery of its targets and the understanding of its molecular modes of action in physiological processes could help in the dissection of the complex SA signalling network, confirming its important role in both plant health and disease. Here, the evidence that supports the role of SA during plant growth and development is reviewed by comparing experiments performed by exogenous application of SA with analysis of genotypes affected by SA levels and/or perception.

  17. Competing mechanisms for perfluoroalkyl acid accumulation in plants revealed using an Arabidopsis model system.

    PubMed

    Müller, Claudia E; LeFevre, Gregory H; Timofte, Anca E; Hussain, Fatima A; Sattely, Elizabeth S; Luthy, Richard G

    2016-05-01

    Perfluoroalkyl acids (PFAAs) bioaccumulate in plants, presenting a human exposure route if present in irrigation water. Curiously, accumulation of PFAAs in plant tissues is greatest for both the short-chain and long-chain PFAAs, generating a U-shaped relationship with chain length. In the present study, the authors decouple competing mechanisms of PFAA accumulation using a hydroponic model plant system (Arabidopsis thaliana) exposed to a suite of 10 PFAAs to determine uptake, depuration, and translocation kinetics. Rapid saturation of root concentrations occurred for all PFAAs except perfluorobutanoate, the least-sorptive (shortest-chain) PFAA. Shoot concentrations increased continuously, indicating that PFAAs are efficiently transported and accumulate in shoots. Tissue concentrations of PFAAs during depuration rapidly declined in roots but remained constant in shoots, demonstrating irreversibility of the translocation process. Root and shoot concentration factors followed the U-shaped trend with perfluoroalkyl chain length; however, when normalized to dead-tissue sorption, this relationship linearized. The authors therefore introduce a novel term, the "sorption normalized concentration factor," to describe PFAA accumulation in plants; because of their hydrophobicity, sorption is the determining factor for long-chain PFAAs, whereas the shortest-chain PFAAs are most effectively transported in the plant. The present study provides a mechanistic explanation for previously unexplained PFAA accumulation trends in plants and suggests that shorter-chained PFAAs may bioaccumulate more readily in edible portions.

  18. Two-Component Elements Mediate Interactions between Cytokinin and Salicylic Acid in Plant Immunity

    PubMed Central

    Argueso, Cristiana T.; Ferreira, Fernando J.; Epple, Petra; To, Jennifer P. C.; Hutchison, Claire E.; Schaller, G. Eric; Dangl, Jeffery L.; Kieber, Joseph J.

    2012-01-01

    Recent studies have revealed an important role for hormones in plant immunity. We are now beginning to understand the contribution of crosstalk among different hormone signaling networks to the outcome of plant–pathogen interactions. Cytokinins are plant hormones that regulate development and responses to the environment. Cytokinin signaling involves a phosphorelay circuitry similar to two-component systems used by bacteria and fungi to perceive and react to various environmental stimuli. In this study, we asked whether cytokinin and components of cytokinin signaling contribute to plant immunity. We demonstrate that cytokinin levels in Arabidopsis are important in determining the amplitude of immune responses, ultimately influencing the outcome of plant–pathogen interactions. We show that high concentrations of cytokinin lead to increased defense responses to a virulent oomycete pathogen, through a process that is dependent on salicylic acid (SA) accumulation and activation of defense gene expression. Surprisingly, treatment with lower concentrations of cytokinin results in increased susceptibility. These functions for cytokinin in plant immunity require a host phosphorelay system and are mediated in part by type-A response regulators, which act as negative regulators of basal and pathogen-induced SA–dependent gene expression. Our results support a model in which cytokinin up-regulates plant immunity via an elevation of SA–dependent defense responses and in which SA in turn feedback-inhibits cytokinin signaling. The crosstalk between cytokinin and SA signaling networks may help plants fine-tune defense responses against pathogens. PMID:22291601

  19. Disinfection of an advanced primary effluent with peracetic acid and ultraviolet combined treatment: a continuous-flow pilot plant study.

    PubMed

    González, Abelardo; Gehr, Ronald; Vaca, Mabel; López, Raymundo

    2012-03-01

    Disinfection of an advanced primary effluent using a continuous-flow combined peracetic acid/ultraviolet (PAA/UV) radiation system was evaluated. The purpose was to determine whether the maximum microbial content, established under Mexican standards for treated wastewaters meant for reuse--less than 240 most probable number fecal coliforms (FC)/100 mL--could be feasibly accomplished using either disinfectant individually, or the combined PAA/UV system. This meant achieving reduction of up to 5 logs, considering initial concentrations of 6.4 x 10(+6) to 5.8 x 10(+7) colony forming units/100 mL. During the tests performed under these experiments, total coliforms (TC) were counted because FC, at the most, will be equal to TC. Peracetic acid disinfection achieved less than 1.5 logs TC reduction when the C(t) x t product was less than 2.26 mg x minimum (min)/L; 3.8 logs for C(t) x t 4.40 mg x min/L; and 5.9 logs for C(t) x t 24.2 mg x min/L. In continuous-flow UV irradiation tests, at a low-operating flow (21 L/min; conditions which produced an average UV fluence of 13.0 mJ/cm2), the highest TC reduction was close to 2.5 logs. The only condition that produced a disinfection efficiency of approximately 5 logs, when both disinfection agents were used together, was the combined process dosing 30 mg PAA/L at a pilot plant flow of 21 L/min and contact time of 10 minutes to attain an average C(t) x t product of 24.2 mg x min/L and an average UV fluence of 13 mJ/cm2. There was no conclusive evidence of a synergistic effect when both disinfectants were employed in combination as compared to the individual effects achieved when used separately, but this does not take into account the nonlinearity (tailing-off) of the dose-response curve.

  20. Self-assembled polyhydroxy fatty acids vesicles: a mechanism for plant cutin synthesis.

    PubMed

    Heredia-Guerrero, José A; Benítez, José J; Heredia, Antonio

    2008-03-01

    Despite its biological importance, the mechanism of formation of cutin, the polymeric matrix of plant cuticles, has not yet been fully clarified. Here, for the first time, we show the participation in the process of lipid vesicles formed by the self-assembly of endogenous polyhydroxy fatty acids. The accumulation and fusion of these vesicles (cutinsomes) at the outer part of epidermal cell wall is proposed as the mechanism for early cuticle formation.

  1. In situ detection of salicylic acid binding sites in plant tissues.

    PubMed

    Liu, Jing-Wen; Deng, Da-Yi; Yu, Ying; Liu, Fang-Fei; Lin, Bi-Xia; Cao, Yu-Juan; Hu, Xiao-Gang; Wu, Jian-Zhong

    2015-02-01

    The determination of hormone-binding sites in plants is essential in understanding the mechanisms behind hormone function. Salicylic acid (SA) is an important plant hormone that regulates responses to biotic and abiotic stresses. In order to label SA-binding sites in plant tissues, a quantum dots (QDs) probe functionalized with a SA moiety was successfully synthesized by coupling CdSe QDs capped with 3-mercaptopropionic acid (MPA) to 4-amino-2-hydroxybenzoic acid (PAS), using 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide (EDC) as the coupling agent. The probe was then characterized by dynamic light scattering and transmission electron microscopy, as well as UV/vis and fluorescence spectrophotometry. The results confirmed the successful conjugation of PAS to CdSe QDs and revealed that the conjugates maintained the properties of the original QDs, with small core diameters and adequate dispersal in solution. The PAS-CdSe QDs were used to detect SA-binding sites in mung bean and Arabidopsis thaliana seedlings in vitro and in vivo. The PAS-CdSe QDs were effectively transported into plant tissues and specifically bound to SA receptors in vivo. In addition, the effects of the PAS-CdSe QDs on cytosolic Ca(2+) levels in the tips of A. thaliana seedlings were investigated. Both SA and PAS-CdSe QDs had similar effects on the trend in cytosolic-free Ca(2+) concentrations, suggesting that the PAS-CdSe QDs maintained the bioactivity of SA. To summarize, PAS-CdSe QDs have high potential as a fluorescent probe for the in vitro/in vivo labeling and imaging of SA receptors in plants.

  2. Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides.

    PubMed

    Gagne, Steve J; Stout, Jake M; Liu, Enwu; Boubakir, Zakia; Clark, Shawn M; Page, Jonathan E

    2012-07-31

    Δ(9)-Tetrahydrocannabinol (THC) and other cannabinoids are responsible for the psychoactive and medicinal properties of Cannabis sativa L. (marijuana). The first intermediate in the cannabinoid biosynthetic pathway is proposed to be olivetolic acid (OA), an alkylresorcinolic acid that forms the polyketide nucleus of the cannabinoids. OA has been postulated to be synthesized by a type III polyketide synthase (PKS) enzyme, but so far type III PKSs from cannabis have been shown to produce catalytic byproducts instead of OA. We analyzed the transcriptome of glandular trichomes from female cannabis flowers, which are the primary site of cannabinoid biosynthesis, and searched for polyketide cyclase-like enzymes that could assist in OA cyclization. Here, we show that a type III PKS (tetraketide synthase) from cannabis trichomes requires the presence of a polyketide cyclase enzyme, olivetolic acid cyclase (OAC), which catalyzes a C2-C7 intramolecular aldol condensation with carboxylate retention to form OA. OAC is a dimeric α+β barrel (DABB) protein that is structurally similar to polyketide cyclases from Streptomyces species. OAC transcript is present at high levels in glandular trichomes, an expression profile that parallels other cannabinoid pathway enzymes. Our identification of OAC both clarifies the cannabinoid pathway and demonstrates unexpected evolutionary parallels between polyketide biosynthesis in plants and bacteria. In addition, the widespread occurrence of DABB proteins in plants suggests that polyketide cyclases may play an overlooked role in generating plant chemical diversity.

  3. Assessment and comparison of 100-MW coal gasification phosphoric acid fuel cell power plants

    NASA Technical Reports Server (NTRS)

    Lu, Cheng-Yi

    1988-01-01

    One of the advantages of fuel cell (FC) power plants is fuel versatility. With changes only in the fuel processor, the power plant will be able to accept a variety of fuels. This study was performed to design process diagrams, evaluate performance, and to estimate cost of 100 MW coal gasifier (CG)/phosphoric acid fuel cell (PAFC) power plant systems utilizing coal, which is the largest single potential source of alternate hydrocarbon liquids and gases in the United States, as the fuel. Results of this study will identify the most promising integrated CG/PAFC design and its near-optimal operating conditions. The comparison is based on the performance and cost of electricity which is calculated under consistent financial assumptions.

  4. Profiling of hydroxycinnamoylquinic acids in plant extracts using in-source CID fragmentation.

    PubMed

    Nagy, Ádám; Abrankó, László

    2016-12-01

    Hydroxycinnamoylquinic acids (HCQAs) are a major class of phenolic plant secondary metabolites, belonging to the chlorogenic acid family. Various health-beneficial properties of HCQAs have been shown, which has drawn interest for HCQA profiling in plants of human consumption. However, this task remains challenging, because several isomeric HCQAs can be present in the sample with identical molecular formulae and the limited availability of reference standards poses additional challenges to their identification. In the present work, a high performance liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (HPLC-ESI-Q/TOF-MS) method accompanied with an effective data filtering protocol is presented, which is shown to be suitable for the identification of HCQAs in plant materials in a non-targeted manner. Both collision-induced dissociation (CID) fragmentation performed in a collision cell and in-source (CID) fragmentation were used to produce accurate mass fragments. It was shown that fragmentation characteristics required for identification of regio-isomers of HCQAs can be achieved with in-source CID fragmentation, enabling the use of a single-stage MS system with in-source fragmentation for convincing identification of HCQAs. Based on a thorough validation of identified HCQA compounds using coffee bean extracts as reference samples, comprehensive profiling of HCQAs in two apricot (Prunus armeniaca L.) genotypes ('Preventa' and 'Gönci magyarkajszi') was carried out for the first time and the following 10 HCQAs were shown to be present in apricot fruit: 3-caffeoylquinic acid (CQA), cis-3-CQA, 4-CQA, 5-CQA, cis-5-CQA, 3,5-diCQA, 3-p-coumaroylquinic acid (pCoQA), 4-pCoQA, 3-feruloylquinic acid (FQA) and cis-3-FQA. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Plant secondary metabolites and gut health: the case for phenolic acids.

    PubMed

    Russell, Wendy; Duthie, Garry

    2011-08-01

    Plant-based diets contain a plethora of secondary metabolites that may impact on health and disease prevention. Much attention has been focused on the potential bioactivity and nutritional relevance of several classes of phytochemicals such as flavonoids, carotenoids, phyto-oestrogens and glucosinolates. Less attention has been paid to simple phenolic acids that are widely found in fruit, vegetables, herbs, spices and beverages. Daily intakes may exceed 100 mg. In addition, bacteria in the gut can perform reactions that transform more complex plant phenolics such as anthocyanins, procyanidins, flavanones, flavonols, tannins and isoflavones into simple phenolic metabolites. The colon is thus a rich source of potentially active phenolic acids that may impact both locally and systemically on gut health. Both the small and large intestine (colon) contain absorption sites for phenolic acids but low post-prandial concentrations in plasma indicate minimal absorption early in the gastrointestinal tract and/or rapid hepatic metabolism and excretion. Therefore, any bioactivity that contributes to gut health may predominantly occur in the colon. Several phenolic acids affect the expression and activity of enzymes involved in the production of inflammatory mediators of pathways thought to be important in the development of gut disorders including colon cancer. However, at present, we remain largely ignorant as to which of these compounds are beneficial to gut health. Until we can elucidate which pro-inflammatory and potentially carcinogenetic changes in gene expression can be moderated by simple phenolic acids, it is not possible to recommend specific plant-based foods rich in particular phenolics to optimise gut health.

  6. Chemical genetics reveals negative regulation of abscisic acid signaling by a plant immune response pathway.

    PubMed

    Kim, Tae-Houn; Hauser, Felix; Ha, Tracy; Xue, Shaowu; Böhmer, Maik; Nishimura, Noriyuki; Munemasa, Shintaro; Hubbard, Katharine; Peine, Nora; Lee, Byeong-Ha; Lee, Stephen; Robert, Nadia; Parker, Jane E; Schroeder, Julian I

    2011-06-07

    Coordinated regulation of protection mechanisms against environmental abiotic stress and pathogen attack is essential for plant adaptation and survival. Initial abiotic stress can interfere with disease-resistance signaling [1-6]. Conversely, initial plant immune signaling may interrupt subsequent abscisic acid (ABA) signal transduction [7, 8]. However, the processes involved in this crosstalk between these signaling networks have not been determined. By screening a 9600-compound chemical library, we identified a small molecule [5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione (DFPM) that rapidly downregulates ABA-dependent gene expression and also inhibits ABA-induced stomatal closure. Transcriptome analyses show that DFPM also stimulates expression of plant defense-related genes. Major early regulators of pathogen-resistance responses, including EDS1, PAD4, RAR1, and SGT1b, are required for DFPM-and notably also for Pseudomonas-interference with ABA signal transduction, whereas salicylic acid, EDS16, and NPR1 are not necessary. Although DFPM does not interfere with early ABA perception by PYR/RCAR receptors or ABA activation of SnRK2 kinases, it disrupts cytosolic Ca(2+) signaling and downstream anion channel activation in a PAD4-dependent manner. Our findings provide evidence that activation of EDS1/PAD4-dependent plant immune responses rapidly disrupts ABA signal transduction and that this occurs at the level of Ca(2+) signaling, illuminating how the initial biotic stress pathway interferes with ABA signaling.

  7. Crassulacean acid metabolism enhances underwater photosynthesis and diminishes photorespiration in the aquatic plant Isoetes australis.

    PubMed

    Pedersen, Ole; Rich, Sarah Meghan; Pulido, Cristina; Cawthray, Gregory Robert; Colmer, Timothy David

    2011-04-01

    • Underwater photosynthesis by aquatic plants is often limited by low availability of CO(2), and photorespiration can be high. Some aquatic plants utilize crassulacean acid metabolism (CAM) photosynthesis. The benefits of CAM for increased underwater photosynthesis and suppression of photorespiration were evaluated for Isoetes australis, a submerged plant that inhabits shallow temporary rock pools. • Leaves high or low in malate were evaluated for underwater net photosynthesis and apparent photorespiration at a range of CO(2) and O(2) concentrations. • CAM activity was indicated by 9.7-fold higher leaf malate at dawn, compared with at dusk, and also by changes in the titratable acidity (μmol H(+) equivalents) of leaves. Leaves high in malate showed not only higher underwater net photosynthesis at low external CO(2) concentrations but also lower apparent photorespiration. Suppression by CAM of apparent photorespiration was evident at a range of O(2) concentrations, including values below air equilibrium. At a high O(2) concentration of 2.2-fold the atmospheric equilibrium concentration, net photosynthesis was reduced substantially and, although it remained positive in leaves containing high malate concentrations, it became negative in those low in malate. • CAM in aquatic plants enables higher rates of underwater net photosynthesis over large O(2) and CO(2) concentration ranges in floodwaters, via increased CO(2) fixation and suppression of photorespiration.

  8. Modeling the plant-soil interaction in presence of heavy metal pollution and acidity variations.

    PubMed

    Guala, Sebastián; Vega, Flora A; Covelo, Emma F

    2013-01-01

    On a mathematical interaction model, developed to model metal uptake by plants and the effects on their growth, we introduce a modification which considers also effects on variations of acidity in soil. The model relates the dynamics of the uptake of metals from soil to plants and also variations of uptake according to the acidity level. Two types of relationships are considered: total and available metal content. We suppose simple mathematical assumptions in order to get as simple as possible expressions with the aim of being easily tested in experimental problems. This work introduces modifications to two versions of the model: on the one hand, the expression of the relationship between the metal in soil and the concentration of the metal in plants and, on the other hand, the relationship between the metal in the soil and total amount of the metal in plants. The fine difference of both versions is fundamental at the moment to consider the tolerance and capacity of accumulation of pollutants in the biomass from the soil.

  9. Air and blood lead levels in lead acid battery recycling and manufacturing plants in Kenya.

    PubMed

    Were, Faridah H; Kamau, Geoffrey N; Shiundu, Paul M; Wafula, Godfrey A; Moturi, Charles M

    2012-01-01

    The concentration of airborne and blood lead (Pb) was assessed in a Pb acid battery recycling plant and in a Pb acid battery manufacturing plant in Kenya. In the recycling plant, full-shift area samples taken across 5 days in several production sections showed a mean value ± standard deviation (SD) of 427 ± 124 μg/m(3), while area samples in the office area had a mean ± SD of 59.2 ± 22.7 μg/m(3). In the battery manufacturing plant, full-shift area samples taken across 5 days in several production areas showed a mean value ± SD of 349 ± 107 μg/m(3), while area samples in the office area had a mean ± SD of 55.2 ± 33.2 μg/m(3). All these mean values exceed the U.S. Occupational Safety and Health Administration's permissible exposure limit of 50 μg/m(3) as an 8-hr time-weighted average. In the battery recycling plant, production workers had a mean blood Pb level ± SD of 62.2 ± 12.7 μg/dL, and office workers had a mean blood Pb level ± SD of 43.4 ± 6.6 μg/dL. In the battery manufacturing plant, production workers had a mean blood Pb level ± SD of 59.5 ± 10.1 μg/dL, and office workers had a mean blood Pb level ± SD of 41.6 ± 7.4 μg/dL. All the measured blood Pb levels exceeded 30 μg/dL, which is the maximum blood Pb level recommended by the ACGIH(®). Observations made in these facilities revealed numerous sources of Pb exposure due to inadequacies in engineering controls, work practices, respirator use, and personal hygiene.

  10. How to eliminate the formation of chlorogenic acids artefacts during plants analysis? Sea sand disruption method (SSDM) in the HPLC analysis of chlorogenic acids and their native derivatives in plants.

    PubMed

    Wianowska, Dorota; Typek, Rafał; Dawidowicz, Andrzej L

    2015-09-01

    The analytical procedures for determining plant constituents involve the application of sample preparation methods to fully isolate and/or pre-concentrate the analyzed substances. High-temperature liquid extraction is still applied most frequently for this purpose. The present paper shows that high-temperature extraction cannot be applied for the analysis of chlorogenic acids (CQAs) and their derivatives in plants as it causes the CQAs transformation leading to erroneous quantitative estimations of these compounds. Experiments performed on different plants (black elder, hawthorn, nettle, yerba maté, St John's wort and green coffee) demonstrate that the most appropriate method for the estimation of CQAs/CQAs derivatives is sea sand disruption method (SSDM) because it does not induce any transformation and/or degradation processes in the analyzed substances. Owing to the SSDM method application we found that the investigated plants, besides four main CQAs, contain sixteen CQAs derivatives, among them three quinic acids. The application of SSDM in plant analysis not only allows to establish a true concentration of individual CQAs in the examined plants but also to determine which chlorogenic acids derivatives are native plant components and what is their concentration level. What is even more important, the application of SSDM in plant analysis allows to eliminate errors that may arise or might have arisen in the study of chlorogenic acids and their derivatives in plant metabolism.

  11. Cell organelles from crassulacean acid metabolism (CAM) plants : II. Compartmentation of enzymes of the crassulacean acid metabolism.

    PubMed

    Schnarrenberger, C; Groß, D; Burkhard, C; Herbert, M

    1980-02-01

    The intracellular distribution of enzymes involved in the Crassulacean acid metabolism (CAM) has been studied in Bryophyllum calycinum Salisb. and Crassula lycopodioides Lam. After separation of cell organelles by isopycnic centrifugation, enzymes of the Crassulacean acid metabolism were found in the following cell fractions: Phosphoenolpyruvate carboxylase in the chloroplasts; NAD-dependent malate dehydrogenase in the mitochondria and in the supernatant; NADP-dependent malate dehydrogenase and phosphoenolpyruvate carboxykinase in the chloroplasts; NADP-dependent malic enzyme in the supernatant and to a minor extent in the chloroplasts; NAD-dependent malic enzyme in the supernatant and to some degree in the mitochondria; and pyruvate; orthophosphate dikinase in the chloroplasts. The activity of the NAD-dependent malate dehydrogenase was due to three isoenzymes separated by (NH4)2SO4 gradient solubilization. These isoenzymes represented 17, 78, and 5% of the activity recovered, respectively, in the order of elution. The isoenzyme eluting first was associated with the mitochondria and the second isoenzyme was of cytosolic origin, while the intracellular location of the third isoenzyme was probably the peroxisome. Based on these findings, the metabolic path of Crassulacean acid metabolism within cells of CAM plants is discussed.

  12. Stearidonic acid, a plant-based dietary fatty acid, enhances the chemosensitivity of canine lymphoid tumor cells.

    PubMed

    Pondugula, Satyanarayana R; Ferniany, Glennie; Ashraf, Farah; Abbott, Kodye L; Smith, Bruce F; Coleman, Elaine S; Mansour, Mahmoud; Bird, R Curtis; Smith, Annette N; Karthikeyan, Chandrabose; Trivedi, Piyush; Tiwari, Amit K

    2015-05-15

    Lymphoma is the most common hematopoietic tumor in dogs and humans, with similar pathogenesis and therapeutic responses. Anticancer drugs like vincristine (VCR) and doxorubicin (DOX) are often used in treating lymphoma. However, the cure rate is generally poor due to chemoresistance. Here, we sought to determine whether stearidonic acid (SDA), a plant-based dietary fatty acid, sensitizes chemoresistant canine lymphoid-tumor cells. GL-1 B-cell lymphoid-tumor cells were found to be highly sensitive to the antitumor-activity of VCR and DOX, while OSW T-cell and 17-71 B-cell lymphoid-tumor cells were moderately and fully resistant, respectively. SDA, at its non-toxic concentrations, significantly promoted the antitumor action of VCR and DOX in both OSW and 17-71 cells. SDA-mediated chemosensitization was associated with SDA inhibition of P-glycoprotein (P-gp) function. This was confirmed in HEK293 cells stably expressing P-gp as well as by increased binding-affinity of SDA to P-gp in P-gp docking analysis. SDA at its chemosensitizing concentrations did not affect the viability of healthy dog peripheral blood mononuclear cells, suggesting that SDA is non-toxic to normal dog peripheral blood leucocytes at its chemosensitizing concentrations. Our study identifies a novel dietary fatty acid that may be used as a dietary supplement in combination with chemotherapy to promote the antitumor efficacy of the chemotherapy drugs in dogs and possibly in humans with chemoresistant lymphoma.

  13. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  14. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  15. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  16. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  17. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  18. Relationships between Stomatal Behavior and Internal Carbon Dioxide Concentration in Crassulacean Acid Metabolism Plants

    PubMed Central

    Cockburn, William; Ting, Irwin P.; Sternberg, Leonel O.

    1979-01-01

    Measurements of internal gas phase CO2 concentration, stomatal resistance, and acid content were made in Crassulacean acid metabolism plants growing under natural conditions. High CO2 concentrations, sometimes in excess of 2%, were observed during the day in a range of taxonomically widely separated plants (Opuntia ficus-indica L., Opuntia basilaris Engelm. and Bigel., Agave desertii Engelm., Yucca schidigera Roezl. ex Ortiges, Ananas comosus [L.] Merr., Aloe vera L., Cattleya sp. and Phalanopsis sp.) and below ambient air concentrations were observed at night. Stomatal resistance was always high when CO2 concentration was high and experiments in which attempts were made to manipulate internal CO2 concentrations gave data consistent with stomatal behavior in Crassulacean acid metabolism being controlled by internal CO2 concentration. Exogenous CO2 applied in darkness at a concentration similar to those observed in the light caused stomatal resistance to increase. In pads of Opuntia basilaris Engelm. and Bigel. subjected to severe water stress internal gas phase CO2 concentrations exhibited fluctuations opposite in phase to fluctuations in acid content. Stomatal resistance remained high and the opening response to low CO2 concentration was almost entirely eliminated. PMID:16660851

  19. Relationships between Stomatal Behavior and Internal Carbon Dioxide Concentration in Crassulacean Acid Metabolism Plants.

    PubMed

    Cockburn, W

    1979-06-01

    Measurements of internal gas phase CO(2) concentration, stomatal resistance, and acid content were made in Crassulacean acid metabolism plants growing under natural conditions. High CO(2) concentrations, sometimes in excess of 2%, were observed during the day in a range of taxonomically widely separated plants (Opuntia ficus-indica L., Opuntia basilaris Engelm. and Bigel., Agave desertii Engelm., Yucca schidigera Roezl. ex Ortiges, Ananas comosus [L.] Merr., Aloe vera L., Cattleya sp. and Phalanopsis sp.) and below ambient air concentrations were observed at night.Stomatal resistance was always high when CO(2) concentration was high and experiments in which attempts were made to manipulate internal CO(2) concentrations gave data consistent with stomatal behavior in Crassulacean acid metabolism being controlled by internal CO(2) concentration. Exogenous CO(2) applied in darkness at a concentration similar to those observed in the light caused stomatal resistance to increase.In pads of Opuntia basilaris Engelm. and Bigel. subjected to severe water stress internal gas phase CO(2) concentrations exhibited fluctuations opposite in phase to fluctuations in acid content. Stomatal resistance remained high and the opening response to low CO(2) concentration was almost entirely eliminated.

  20. Photosynthesis and water relations in tomato plants cultivated long-term in media containing (+)-usnic acid.

    PubMed

    Latkowska, E; Lechowski, Z; Bialczyk, J; Pilarski, J

    2006-09-01

    The influence of (+)-usnic acid on rates of gas exchange (photosynthesis, respiration, and transpiration) in long-term cultivation of tomato plants was studied. The effect was dose-dependent. Plants grown in media containing the maximum concentration of (+)-usnic acid (30 muM) had photosynthetic and respiration rates reduced by 41% and 80%, respectively. The effect on photosynthesis rate may be the result of a multidirectional effect at various stages of this process, which at the highest usnic acid concentration underwent reduction: content of chlorophylls by 30%, carotenoids by 35%, and Hill reaction activity by 75%. Usnic acid also raises the susceptibility of chlorophyll to photodegradation. Under some conditions, transpiration was reduced by 2.1-fold in light and 3.7-fold in dark. This result was correlated with (1) an increase in the diffusive resistance of the stomata (3.1-fold in upper and 1.5-fold in lower surface of leaf), (2) a reduction of stomata density (by 60% on upper and 40% on lower surface), and (3) a 12.3-fold decrease in root hydraulic conductance.

  1. Regulation of epinasty induced by 2,4-dichlorophenoxyacetic acid in pea and Arabidopsis plants.

    PubMed

    Pazmiño, D M; Rodríguez-Serrano, M; Sanz, M; Romero-Puertas, M C; Sandalio, L M

    2014-07-01

    The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) causes uncontrolled cell division and malformed growth in plants, giving rise to leaf epinasty and stem curvature. In this study, mechanisms involved in the regulation of leaf epinasty induced by 2,4-D were studied using different chemicals involved in reactive oxygen species (ROS) accumulation (diphenyleniodonium, butylated hydroxyanisole, EDTA, allopurinol), calcium channels (LaCl3), protein phosphorylation (cantharidin, wortmannin) and ethylene emission/perception (aminoethoxyvinyl glycine, AgNO3). The effect of these compounds on the epinasty induced by 2,4-D was analysed in shoots and leaf strips from pea plants. For further insight into the effect of 2,4-D, studies were also made in Arabidopsis mutants deficient in ROS production (rbohD, rbohF, xdh), ethylene (ein 3-1, ctr 1-1, etr 1-1), abscisic acid (aba 3.1), and jasmonic acid (coi 1.1, jar 1.1, opr 3) pathways. The results suggest that ROS production, mainly ·OH, is essential in the development of epinasty triggered by 2,4-D. Epinasty was also found to be regulated by Ca2+, protein phosphorylation and ethylene, although all these factors act downstream of ROS production. The use of Arabidopsis mutants appears to indicate that abscisic and jasmonic acid are not involved in regulating epinasty, although they could be involved in other symptoms induced by 2,4-D.

  2. Regulation by organic acids of polysaccharide-mediated microbe-plant interactions.

    PubMed

    Nakata, K; Kobayashi, T; Takiguchi, Y; Yamaguchi, T

    2000-10-01

    A polysaccharide flocculant of Klebsiella pneumoniae H12 has been suggested to mediate microbe-plant interactions with the aid of Ca2+ [K. Nakata et al., Biosci. Biotechnol. Biochem., 64, 459-465, 2000]. Here, two-way regulation of polysaccharide-mediated interactions between K. pneumoniae and Raphanus sativus was studied using organic acids. Namely, 10 mM equivalents of organic acids promoted production of the polysaccharide by the bacterium, but inhibited flocculation of bacterial cells by the polysaccharide. These phenomena were counterbalanced by equi-molar equivalents of Ca2+, suggesting competition for Ca2+ between the carboxylic residues of the polysaccharide and those of the aliphatic acids. By electron microscopy observations, bacterial cell aggregates were sparsely distributed over the main roots and root hairs, had various sizes, and seemed to tightly adhere to root tissues. Their shapes seemed to be distorted and abundant in cavities. In brief, these microscopical observations may be explained by a two-way regulation system of bacterial adhesion to a plant by organic acids.

  3. Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium Azospirillum spp.

    NASA Astrophysics Data System (ADS)

    Rodriguez, Hilda; Gonzalez, Tania; Goire, Isabel; Bashan, Yoav

    2004-11-01

    In vitro gluconic acid formation and phosphate solubilization from sparingly soluble phosphorus sources by two strains of the plant growth-promoting bacteria A. brasilense (Cd and 8-I) and one strain of A. lipoferum JA4 were studied. Strains of A. brasilense were capable of producing gluconic acid when grown in sparingly soluble calcium phosphate medium when their usual fructose carbon source is amended with glucose. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. To a greater extent, gluconic acid production and pH reduction were observed for A. lipoferum JA4. For the three strains, clearing halos were detected on solid medium plates with calcium phosphate. This is the first report of in vitro gluconic acid production and direct phosphate solubilization by A. brasilense and the first report of P solubilization by A. lipoferum. This adds to the very broad spectrum of plant growth-promoting abilities of this genus.

  4. How do crop plants tolerate acid soils? Mechanisms of aluminum tolerance and phosphorous efficiency.

    PubMed

    Kochian, Leon V; Hoekenga, Owen A; Pineros, Miguel A

    2004-01-01

    Acid soils significantly limit crop production worldwide because approximately 50% of the world's potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring tolerance to acid soil stress has been a focus of intense research interest over the past decade. The primary limitations on acid soils are toxic levels of aluminum (Al) and manganese (Mn), as well as suboptimal levels of phosphorous (P). This review examines our current understanding of the physiological, genetic, and molecular basis for crop Al tolerance, as well as reviews the emerging area of P efficiency, which involves the genetically based ability of some crop genotypes to tolerate P deficiency stress on acid soils. These are interesting times for this field because researchers are on the verge of identifying some of the genes that confer Al tolerance in crop plants; these discoveries will open up new avenues of molecular/physiological inquiry that should greatly advance our understanding of these tolerance mechanisms. Additionally, these breakthroughs will provide new molecular resources for improving crop Al tolerance via both molecular-assisted breeding and biotechnology.

  5. Removal characteristics of sulfuric acid aerosols from coal-fired power plants.

    PubMed

    Pan, Danping; Yang, Linjun; Wu, Hao; Huang, Rongting

    2017-03-01

    With increasing attention on sulfuric acid emission, investigations on the removal characteristics of sulfuric acid aerosols by the limestone gypsum wet flue gas desulfurization (WFGD) system and the wet electrostatic precipitator (WESP) were carried out in two coal-fired power plants, and the effects of the WFGD scrubber type and the flue gas characteristics were discussed. The results showed that it was necessary to install the WESP device after desulfurization, as the WFGD system was inefficient to remove sulfuric acid aerosols from the flue gas. The removal efficiency of sulfuric acid aerosols in the WFGD system with double scrubbers ranged from 50% to 65%, which was higher than that with a single scrubber, ranging from 30% to 40%. Furthermore, the removal efficiency of WESP on the sulfuric acid aerosols was from 47.9% to 52.4%. With increased concentrations of SO3 and particles in the flue gas, the removal efficiencies of the WFGD and the WESP on the sulfuric acid aerosols were increased.

  6. Application of microchip-CE electrophoresis to follow the degradation of phenolic acids by aquatic plants.

    PubMed

    Ding, Yongsheng; Garcia, Carlos D

    2006-12-01

    In this paper, we describe the separation and detection of six phenolic acids using an electrophoretic microchip with pulsed amperometric detection (PAD). The selected phenolic acids are particularly important because of their biological activity. The analysis of these compounds is typically performed by chromatography or standard CE coupled with a wide variety of detection modes. However, these methods are slow, labor intensive, involve a multistep solvent extraction, require skilled personnel, or use bulky and expensive instrumentation. In contrast, microchip CE offers the possibility of performing simpler, less expensive, and faster analysis. In addition, integrated devices can be custom-fabricated and incorporated with portable computers to perform on-site analysis. In the present report, the effect of the separation potential, buffer pH and composition, injection time and PAD parameters were studied in an effort to optimize both the separation and detection of these phenolic acids. Using the optimized conditions, the analysis can be performed in less than 3 min, with detection limits ranging from 0.73 microM (0.10 microg/mL) for 4-hydroxyphenylacetic acid to 2.12 microM (0.29 microg/mL) for salicylic acid. In order to demonstrate the capabilities of the device, the degradation of a mixture of these acids by two aquatic plants was followed using the optimized conditions.

  7. Fatty acids and sterols composition, and antioxidant activity of oils extracted from plant seeds.

    PubMed

    Kozłowska, Mariola; Gruczyńska, Eliza; Ścibisz, Iwona; Rudzińska, Magdalena

    2016-12-15

    This study determined and compared the contents of bioactive components in plant seed oils extracted with n-hexane (Soxhlet method) and chloroform/methanol (Folch method) from coriander, caraway, anise, nutmeg and white mustard seeds. Oleic acid dominated among unsaturated fatty acids in nutmeg and anise seed oils while petroselinic acid was present in coriander and caraway oils. Concerning sterols, β-sitosterol was the main component in seed oils extracted with both methods. The content of total phenolics in nutmeg, white mustard and coriander seed oils extracted with chloroform/methanol was higher than in their counterparts prepared with n-hexane. The seed oil samples extracted according to the Folch method exhibited a higher ability to scavenge DPPH radicals compared to the oil samples prepared with the Soxhlet method. DPPH values of the methanolic extracts derived from oils produced with the Folch method were also higher than in the oils extracted with n-hexane.

  8. Enrichment of By-Product Materials from Steel Pickling Acid Regeneration Plants (TRP 9942)

    SciTech Connect

    Lu Swan, Delta Ferrites LLC

    2009-09-30

    A new process for manufacturing an enriched, iron-based product (strontium hexaferrite) in existing steel pickling acid regeneration facilities was evaluated. Process enhancements and equipment additions were made to an existing acid regeneration plant to develop and demonstrate (via pilot scale testing and partial-capacity production trials) the viability of a patented method to produce strontium-based compounds that, when mixed with steel pickling acid and roasted, would result in a strontium hexaferrite powder precursor which could then be subjected to further heat treatment in an atmosphere that promotes rapid, relatively low-temperature formation of discrete strontium hexaferrite magnetic domains yielding an enriched iron-based product, strontium hexaferrite, that can be used in manufacturing hard ferrite magnets.

  9. HPLC-Profiles of Tocopherols, Sugars, and Organic Acids in Three Medicinal Plants Consumed as Infusions

    PubMed Central

    Roriz, Custódio Lobo; Barros, Lillian; Carvalho, Ana Maria; Ferreira, Isabel C. F. R.

    2014-01-01

    Pterospartum tridentatum (L.) Willk, Gomphrena globosa L., and Cymbopogon citratus (DC.) Stapf are medicinal plants that require a more detailed chemical characterization, given the importance of their consumption as infusions. Therefore, the individual profiles in tocopherols, free sugars, and organic acids were obtained by high performance liquid chromatography (HPLC) coupled to different detectors (fluorescence, refraction index, and photodiode array, resp.). C. citratus revealed the highest content of α-, and total tocopherols, glucose, sucrose, succinic, and ascorbic acids. P. tridentatum presented the highest fructose and total sugars content. Otherwise, G. globosa showed the highest organic acids concentration. As far as we know, this is the first study reporting the mentioned chemical compounds in G. globosa and C. citratus. PMID:26904623

  10. Accumulation of seleno-amino acids in legume and grass plant species grown in selenium-laden soils

    SciTech Connect

    Wu, L.; Guo, X.; Banuelos, G.S.

    1997-03-01

    Seleno-amino acid accumulation was studied for two legume and two grass species grown in Selenium (Se)-laden soils. An antagonistic relationship was found between the tissue Se-amino acid concentration and the corresponding sulfur-amino acid concentration. This relationship demonstrates a competitive interaction between Se and sulfate at the amino acid synthesis level. The nonsulfur-containing amino acids were not substantially affected by the increase of tissue Se concentration. Sour clover (Melilotus indica L.) was able to accumulate much greater tissue Se concentration than the other three species. Tissue methionine concentration of sour clover, rabbitfoot grass (Polypogon monspeliensis L.), and tall fescue (Festuca arundinacea Schreb.) was not significantly affected by the increase of tissue selenomethionine concentration, but a highly significant negative correlation was found in alfalfa (Medicago sativa L.). This discrepancy suggests that a less antagonistic effect on sulfur-amino acids under the increase of Se-amino acid analogues in the tissue might be able to minimize Se toxicity to the plant. Both Se-methylselenocysteine (nonprotein amino acid) and selenomethionine (protein amino acid) accumulated in the plants when grown in Se-laden soils. Possible effects of these Se-amino acids accumulated by plants on animal health should be tested before the plants are used for forage supplementation.

  11. Multiple Targets of Salicylic Acid and Its Derivatives in Plants and Animals

    PubMed Central

    Klessig, Daniel F.; Tian, Miaoying; Choi, Hyong Woo

    2016-01-01

    Salicylic acid (SA) is a critical plant hormone that is involved in many processes, including seed germination, root initiation, stomatal closure, floral induction, thermogenesis, and response to abiotic and biotic stresses. Its central role in plant immunity, although extensively studied, is still only partially understood. Classical biochemical approaches and, more recently, genome-wide high-throughput screens have identified more than two dozen plant SA-binding proteins (SABPs), as well as multiple candidates that have yet to be characterized. Some of these proteins bind SA with high affinity, while the affinity of others exhibit is low. Given that SA levels vary greatly even within a particular plant species depending on subcellular location, tissue type, developmental stage, and with respect to both time and location after an environmental stimulus such as infection, the presence of SABPs exhibiting a wide range of affinities for SA may provide great flexibility and multiple mechanisms through which SA can act. SA and its derivatives, both natural and synthetic, also have multiple targets in animals/humans. Interestingly, many of these proteins, like their plant counterparts, are associated with immunity or disease development. Two recently identified SABPs, high mobility group box protein and glyceraldehyde 3-phosphate dehydrogenase, are critical proteins that not only serve key structural or metabolic functions but also play prominent roles in disease responses in both kingdoms. PMID:27303403

  12. Phosphatidic Acid Produced by Phospholipase D Promotes RNA Replication of a Plant RNA Virus

    PubMed Central

    Hyodo, Kiwamu; Taniguchi, Takako; Manabe, Yuki; Kaido, Masanori; Mise, Kazuyuki; Sugawara, Tatsuya; Taniguchi, Hisaaki; Okuno, Tetsuro

    2015-01-01

    Eukaryotic positive-strand RNA [(+)RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+)RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD) is a phosphatidylcholine- and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids), but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+)RNA virus, Red clover necrotic mosaic virus (RCNMV). We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLDα and PLDβ. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate. PMID:26020241

  13. Biochemical Evaluation of the Decarboxylation and Decarboxylation-Deamination Activities of Plant Aromatic Amino Acid Decarboxylases*

    PubMed Central

    Torrens-Spence, Michael P.; Liu, Pingyang; Ding, Haizhen; Harich, Kim; Gillaspy, Glenda; Li, Jianyong

    2013-01-01

    Plant aromatic amino acid decarboxylase (AAAD) enzymes are capable of catalyzing either decarboxylation or decarboxylation-deamination on various combinations of aromatic amino acid substrates. These two different activities result in the production of arylalkylamines and the formation of aromatic acetaldehydes, respectively. Variations in product formation enable individual enzymes to play different physiological functions. Despite these catalytic variations, arylalkylamine and aldehyde synthesizing AAADs are indistinguishable without protein expression and characterization. In this study, extensive biochemical characterization of plant AAADs was performed to identify residues responsible for differentiating decarboxylation AAADs from aldehyde synthase AAADs. Results demonstrated that a tyrosine residue located on a catalytic loop proximal to the active site of plant AAADs is primarily responsible for dictating typical decarboxylase activity, whereas a phenylalanine at the same position is primarily liable for aldehyde synthase activity. Mutagenesis of the active site phenylalanine to tyrosine in Arabidopsis thaliana and Petroselinum crispum aromatic acetaldehyde synthases primarily converts the enzymes activity from decarboxylation-deamination to decarboxylation. The mutation of the active site tyrosine to phenylalanine in the Catharanthus roseus and Papaver somniferum aromatic amino acid decarboxylases changes the enzymes decarboxylation activity to a primarily decarboxylation-deamination activity. Generation of these mutant enzymes enables the production of unusual AAAD enzyme products including indole-3-acetaldehyde, 4-hydroxyphenylacetaldehyde, and phenylethylamine. Our data indicates that the tyrosine and phenylalanine in the catalytic loop region could serve as a signature residue to reliably distinguish plant arylalkylamine and aldehyde synthesizing AAADs. Additionally, the resulting data enables further insights into the mechanistic roles of active site

  14. Plant and Soil Emissions of Amines and Amino Acids: A Source of Secondary Aerosol Precursors

    NASA Astrophysics Data System (ADS)

    Jackson, M. L.; Doskey, P. V.; Pypker, T. G.

    2011-12-01

    Ammonia (NH3) is the most abundant alkaline gas in the atmosphere and forms secondary aerosol by neutralizing sulfuric and nitric acids that are released during combustion of fossil fuels. Ammonia is primarily emitted by cropping and livestock operations. However, C2 and C3 amines (pKb 3.3-3.4), which are stronger bases than NH3 (pKb 4.7) have been observed in nuclei mode aerosol that is the precursor to secondary aerosol. Mixtures of amines and amino acids have been identified in diverse environments in aerosol, fog water, cloud water, the soluble fraction of precipitation, and in dew. Glycine (pKb 4.2), serine (pKb 4.8) and alanine (pKb 3.7 and 4.1 for the D and L forms, respectively) are typically the most abundant species. The only reported values of gas-phase glycine, serine and alanine were in marine air and ranged from 6-14 pptv. The origin of atmospheric amines and amino acids has not been fully identified, although sources are likely similar to NH3. Nitrate assimilation in plants forms glycine, serine, and L-alanine, while D-alanine is present in bacterial cell walls. Glycine is converted to serine during C3 plant photorespiration, producing CO2 and NH3. Bacteria metabolize glycine and alanine to methylamine and ethylamine via decarboxylation. Likely sources of amino acids are plants and bacteria, thus concentrations near continental sources are likely greater than those measured in marine air. The overall goal of the research is to examine seasonal variations and relationships between the exchange of CO2, NH3, amines, and amino acids with a corn/soybean rotation in the Midwest Corn Belt. The study presents gaseous profiles of organic amine compounds from various species of vegetation using a mist chamber trapping technique and analysis of the derivatized species by high pressure liquid chromatography with fluorescence detection. Amino acid and amine profiles were obtained for red oak (Quercus rubra), sugar maple (Acer saccharinum), white pine (Pinus

  15. Isolation and characterization of mutants of common ice plant deficient in crassulacean acid metabolism.

    PubMed

    Cushman, John C; Agarie, Sakae; Albion, Rebecca L; Elliot, Stewart M; Taybi, Tahar; Borland, Anne M

    2008-05-01

    Crassulacean acid metabolism (CAM) is a specialized mode of photosynthesis that improves water use efficiency by shifting part or all of net atmospheric CO2 uptake to the night. Genetic dissection of regulatory and metabolic attributes of CAM has been limited by the difficulty of identifying a reliable phenotype for mutant screening. We developed a novel and simple colorimetric assay to measure leaf pH to screen fast neutron-mutagenized populations of common ice plant (Mesembryanthemum crystallinum), a facultative CAM species, to detect CAM-deficient mutants with limited nocturnal acidification. The isolated CAM-deficient mutants showed negligible net dark CO2 uptake compared with wild-type plants following the imposition of salinity stress. The mutants and wild-type plants accumulated nearly comparable levels of sodium in leaves, but the mutants grew more slowly than the wild-type plants. The mutants also had substantially reduced seed set and seed weight relative to wild type under salinity stress. Carbon-isotope ratios of seed collected from 4-month-old plants indicated that C3 photosynthesis made a greater contribution to seed production in mutants compared to wild type. The CAM-deficient mutants were deficient in leaf starch and lacked plastidic phosphoglucomutase, an enzyme critical for gluconeogenesis and starch formation, resulting in substrate limitation of nocturnal C4 acid formation. The restoration of nocturnal acidification by feeding detached leaves of salt-stressed mutants with glucose or sucrose supported this defect and served to illustrate the flexibility of CAM. The CAM-deficient mutants described here constitute important models for exploring regulatory features and metabolic consequences of CAM.

  16. Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments

    PubMed Central

    Lüttge, Ulrich

    2010-01-01

    Background and aims Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO2, light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. Crassulacean acid metabolism The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. Tropical CAM habitats Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. Morphotypical and physiotypical plasticity of CAM Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity). PMID:22476063

  17. Fact Sheet - Final Air Toxics Rule for Steel Pickling and HCI Process Facilities and Hydrochloric Acid Regeneration Plants

    EPA Pesticide Factsheets

    Fact Sheet summarizing the main points of the national emssions standard for hazaradous air pollutants (NESHAP) for Steel Pickling— HCl Process Facilities and Hydrochloric Acid Regeneration Plants as promulgated on June 22, 1999.

  18. Managing 'tail liability'.

    PubMed

    Frese, Richard C; Weber, Ryan J

    2013-11-01

    To reduce and control their level of tail liability, hospitals should: Utilize a self-insurance vehicle; Consider combined limits between the hospital and physicians; Communicate any program changes to the actuary, underwriter, and auditor; Continue risk management and safety practices; Ensure credit is given to the organization's own medical malpractice program.

  19. Effect of 1-naphthaleneacetic acid on organic acid exudation by the roots of white lupin plants grown under phosphorus-deficient conditions.

    PubMed

    Gómez, Diego A; Carpena, Ramón O

    2014-09-15

    The effect of NAA (1-naphthaleneacetic acid) on organic acid exudation in white lupin plants grown under phosphorus deficiency was investigated. Plants were sampled periodically for collecting of organic acids (citrate, malate, succinate), and also were used to study the effect on proton extrusion and release of Na(+), K(+), Ca(2+) and Mg(2+). The tissues were later processed to quantify the organic acids in tissues, the phosphorus content and the effects on plant biomass. The exogenous addition of NAA led to an increase in organic acid exudation, but this response was not proportional to the concentration of the dose applied, noticing the largest increments with NAA 10(-8)M. In contrast the increase in root weight was proportional to the dose applied, which shows that with higher doses the roots produced are not of proteoid type. Proton extrusion and the release of cations were related to the NAA dose, the first was proportional to the dose applied and the second inversely proportional. Regarding the analysis of tissues, the results of citrate and phosphorus content in shoots show that the overall status of these parts are the main responsible of the organic acids exuded. NAA served as an enhancer of the organic acid exudation that occurs under phosphorus deficient conditions, with a response that depends on the dose applied, not only in its magnitude, but also in the mechanism of action of the plant hormone.

  20. Nesting habitat relationships of sympatric Crested Caracaras, Red-tailed Hawks, and White-tailed Hawks in South Texas

    USGS Publications Warehouse

    Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

    2007-01-01

    We quantified nesting-site habitats for sympatric White-tailed Hawks (Buteo albicaudatus) (n = 40), Red-tailed Hawks (B. jamaicensis) (n = 39), and Crested Caracaras (Caracara cheriway) (n = 24) in the Coastal Sand Plain of south Texas. White-tailed Hawks and Crested Caracara nest sites occurred in savannas, whereas Red-tailed Hawk nest sites occurred in woodlands on the edge of savannas. White-tailed Hawk nest sites were in shrubs and trees that were shorter (3.5 ?? 1.0 m) and had smaller canopy diameters (5.5 ?? 2.1 m) than those of Red-tailed Hawks (10.1 ?? 2.0 m, 13.7 ?? 5.8 m) and Crested Caracaras (5.6 ?? 1.7 m, 8.5 ?? 3.5 m). Red-tailed Hawk nest sites had higher woody densities (15.7 ?? 9.6 plants) and more woody cover (84 ?? 19%) than those of White-tailed Hawks (5.6 ?? 5.8 plants, 20 ?? 21%) and Crested Caracaras (9.9 ?? 6.7 plants, 55 ?? 34%). Crested Caracara nest sites were in dense, multi-branched shrubs composed of more living material (97 ?? 3%) than those of White-tailed (88 ?? 18%) and Red-tailed hawks (88 ?? 18%). Nest sites of White-tailed Hawks, Red-tailed Hawks, and Crested Caracaras were similar to random samples from the surrounding habitat indicating that preferred nesting habitat was available for each of these species at least within 60 m of active nest sites. Nest tree height, along with woody plant and native grass cover best discriminated nest sites among the three raptor species. There was no overlap at Red-tailed and White-tailed hawk nest sites in vegetation structure, while Crested Caracara nests were in habitat intermediate between the two other species. Partitioning of nesting habitat may be how these raptor species co-exist at the broader landscape scale of our study area in the Coastal Sand Plain of Texas.

  1. Salicylic acid and gentisic acid induce RNA silencing-related genes and plant resistance to RNA pathogens.

    PubMed

    Campos, Laura; Granell, Pablo; Tárraga, Susana; López-Gresa, Pilar; Conejero, Vicente; Bellés, José María; Rodrigo, Ismael; Lisón, Purificación

    2014-04-01

    We have observed that treatments with salicylic acid (SA) or gentisic acid (GA) induced resistance to RNA pathogens such as ToMV and CEVd in tomato and Gynura auriantiaca, respectively. Accumulation of SA and GA has been found to occur in plants infected by these pathogens, thus pointing out a possible defence role of both molecules. To study the molecular basis of the observed induced resistance to RNA pathogens the induction of silencing-related genes by SA and GA was considered. For that purpose, we searched for tomato genes which were orthologous to those described in Arabidopsis thaliana, such as AtDCL1, AtDCL2, AtDCL4, AtRDR1, AtRDR2 and AtRDR6, and we tracked their induction in tomato along virus and viroid infections. We observed that CEVd significantly induced all these genes in tomato, with the exception of ToRDR6, being the induction of ToDCL4 the most outstanding. Regarding the ToMV asymptomatic infection, with the exception of ToRDR2, we observed a significant induction of all the indicated silencing-related genes, being ToDCL2 the most induced gene. Subsequently, we analyzed their transcriptional activation by SA and at the time when ToMV was inoculated on plants. ToDCL2, ToRDR1 and ToRDR2 were significantly induced by both SA and GA, whereas ToDCL1 was only induced by SA. Such an induction resulted more effective by SA treatment, which is in agreement with the stronger SA-induced resistance observed. Our results suggest that the observed delay in the RNA pathogen accumulation could be due to the pre-induction of RNA silencing-related genes by SA or GA.

  2. Occurrence of carboxylic acids in different steps of two drinking-water treatment plants using different disinfectants.

    PubMed

    Jurado-Sánchez, Beatriz; Ballesteros, Evaristo; Gallego, Mercedes

    2014-03-15

    The occurrence of 35 aliphatic and aromatic carboxylic acids within two full scale drinking-water treatment plants was evaluated for the first time in this research. At the intake of each plant (raw water), the occurrence of carboxylic acids varied according to the quality of the water source although in both cases 13 acids were detected at average concentrations of 6.9 and 4.7 μg/L (in winter). In the following steps in each treatment plant, the concentration patterns of these compounds differed depending on the type of disinfectant applied. Thus, after disinfection by chloramination, the levels of the acids remained almost constant (average concentration, 6.3 μg/L) and four new acids were formed (butyric, 2-methylbutyric, 3-hydroxybenzoic and 2-nitrobenzoic) at low levels (1.1-5 μg/L). When ozonation/chlorination was used, the total concentration of the carboxylic acids in the raw water sample (4.7 μg/L) increased up to 6 times (average concentration, 26.3 μg/L) after disinfection and 6 new acids (mainly aromatic) were produced at high levels (3.5-100 μg/L). Seasonal variations of the carboxylic acids under study showed that in both plants, maximum levels of all the analytes were reached in the coldest months (autumn and winter), aromatic acids only being found in those seasons.

  3. Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils.

    PubMed

    Richardson, Christine E; Hennebelle, Marie; Otoki, Yurika; Zamora, Daisy; Yang, Jun; Hammock, Bruce D; Taha, Ameer Y

    2017-03-08

    Linoleic acid (LA) and α-linolenic acid (ALA) in plant or algae oils are precursors to oxidized fatty acid metabolites known as oxylipins. Liquid chromatography tandem mass spectrometry was used to quantify oxylipins in soybean, corn, olive, canola, and four high-oleic acid algae oils at room temperature or after heating for 10 min at 100 °C. Flaxseed oil oxylipin concentrations were determined in a follow-up experiment that compared it to soybean, canola, corn, and olive oil. Published consumption data for soybean, canola, corn, and olive oil were used to estimate daily oxylipin intake. The LA and ALA fatty acid composition of the oils was generally related to their respective oxylipin metabolites, except for olive and flaxseed oil, which had higher LA derived monohydroxy and ketone oxylipins than other oils, despite their low LA content. Algae oils had the least amount of oxylipins. The change in oxylipin concentrations was not significantly different among the oils after short-term heating. The estimated oxylipin intake from nonheated soybean, canola, corn, and olive oil was 1.1 mg per person per day. These findings suggest that oils represent a dietary source of LA and ALA derived oxylipins and that the response of oils to short-term heating does not differ among the various oils.

  4. Plant immunity induced by COS-OGA elicitor is a cumulative process that involves salicylic acid.

    PubMed

    van Aubel, Géraldine; Cambier, Pierre; Dieu, Marc; Van Cutsem, Pierre

    2016-06-01

    Plant innate immunity offers considerable opportunities for plant protection but beside flagellin and chitin, not many molecules and their receptors have been extensively characterized and very few have successfully reached the field. COS-OGA, an elicitor that combines cationic chitosan oligomers (COS) with anionic pectin oligomers (OGA), efficiently protected tomato (Solanum lycopersicum) grown in greenhouse against powdery mildew (Leveillula taurica). Leaf proteomic analysis of plants sprayed with COS-OGA showed accumulation of Pathogenesis-Related proteins (PR), especially subtilisin-like proteases. qRT-PCR confirmed upregulation of PR-proteins and salicylic acid (SA)-related genes while expression of jasmonic acid/ethylene-associated genes was not modified. SA concentration and class III peroxidase activity were increased in leaves and appeared to be a cumulative process dependent on the number of sprayings with the elicitor. These results suggest a systemic acquired resistance (SAR) mechanism of action of the COS-OGA elicitor and highlight the importance of repeated applications to ensure efficient protection against disease.

  5. Oxalic acid enhances Cr tolerance in the accumulating plant Leersia hexandra Swartz.

    PubMed

    Wang, Dunqiu; Zhang, Xuehong; Liu, Jie; Zhu, Yinian; Zhang, Hui; Zhang, Aili; Jin, Xiaodan

    2012-12-01

    This study examined the relationship between oxalic acid and Cr tolerance in an accumulating plant Leersia hexandra Swartz. The plants grown in hydroponics were exposed to Cr at 0, 5, 30, and 60 mg/L (without oxalate), and 0, 40, and 80 mg/L concentrations of Cr (with 70 mg/L oxalate or without oxalate). The results showed that more than 50% of Cr in shoots was found in HCl-extracted fraction (chromium oxalate) when the plants were exposed to Cr. Cr supply significantly increased oxalate concentration in shoots of L. hexandra (p < 0.05), but did not increase oxalate concentration in roots. Under 80 mg/L Cr stress, electrolyte leakages from roots and shoots with oxalate treatment were both significantly lower than those without oxalate treatment (p < 0.05), indicating exogenous oxalate supply alleviated Cr-induced membrane damage. Oxalate added to growth solution ameliorated reduction of biomass and inhibition of root growth induced by Cr, which demonstrated that application of oxalate helped L. hexandra tolerate Cr stress. However, oxalate supply did not affect the Cr concentrations both in roots and shoots of L. hexandra. These results suggest that oxalic acid may act as an important chelator and takes part in detoxifying chromium in internal process of L. hexandra.

  6. Transporters for ammonium, amino acids and peptides are expressed in pitchers of the carnivorous plant Nepenthes.

    PubMed

    Schulze, W; Frommer, W B; Ward, J M

    1999-03-01

    Insect capture and digestion contribute substantially to the nitrogen budget of carnivorous plants. In Nepenthes, insect-derived nitrogenous compounds are imported from the pitcher fluid and transported throughout the plant via the vascular tissue to support growth. Import and distribution of nutrients may require transmembrane nitrogen transporters. Representatives of three classes of genes encoding transporters for the nitrogenous compounds ammonium, amino acids and peptides were identified in Nepenthes pitchers. The expression at the cellular level of an ammonium transporter gene, three amino acid transporter genes, and one peptide transporter gene were investigated in the insect trapping organs of Nepenthes. Expression of the ammonium transporter gene NaAMT1 was detected in the head cells of digestive glands in the lower part of the pitcher where NaAMT1 may function in ammonium uptake from the pitcher fluid. One amino acid transporter gene, NaAAP1, was expressed in bundle sheath cells surrounding the vascular tissue. To understand the locations where transmembrane transport could be required within the pitcher, symplasmic and apoplasmic continuity was probed using fluorescent dyes. Symplasmic connections were not found between cortical cells and vascular bundles. Therefore, the amino acid transporter encoded by NaAAP1 may be involved in transport of amino acids into the vascular tissue. In contrast, expression of the peptide transporter gene NaNTR1 was detected in phloem cells of the vascular tissue within pitchers. NaNTR1 may function in the export of nitrogen from the pitcher by loading peptides into the phloem.

  7. Plant growth inhibition by cis-cinnamoyl glucosides and cis-cinnamic acid.

    PubMed

    Hiradate, Syuntaro; Morita, Sayaka; Furubayashi, Akihiro; Fujii, Yoshiharu; Harada, Jiro

    2005-03-01

    Spiraea thunbergii Sieb. contains 1-O-cis-cinnamoyl-beta-D-glucopyranose (CG) and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (BCG) as major plant growth inhibiting constituents. In the present study, we determined the inhibitory activity of CG and BCG on root elongation of germinated seedlings of lettuce (Lactuca sativa), pigweed (Amaranthus retroflexus), red clover (Trifolium pratense), timothy (Phleum pratense), and bok choy (Brassica rapa var chinensis) in comparison with that of two well-known growth inhibitors, 2,4-dichlorophenoxyacetic acid (2,4-D) and (+)-2-cis-4-trans-abscisic acid (cis-ABA), as well as two related chemicals of CG and BCG, cis-cinnamic acid (cis-CA) and trans-cinnamic acid (trans-CA). The EC50 values for CG and BCG on lettuce were roughly one-half to one-quarter of the value for cis-ABA. cis-Cinnamic acid, which is a component of CG and BCG, possessed almost the same inhibitory activity of CG and BCG, suggesting that the essential chemical structure responsible for the inhibitory activity of CG and BCG is cis-CA. The cis-stereochemistry of the methylene moiety is apparently needed for high inhibitory activity, as trans-CA had an EC50 value roughly 100 times that of CG, BCG, and cis-CA. Growth inhibition by CG, BCG, and cis-CA was influenced by the nature of the soil in the growing medium: alluvial soil preserved the bioactivity, whereas volcanic ash and calcareous soils inhibited bioactivity. These findings indicate a potential role of cis-CA and its glucosides as allelochemicals for use as plant growth regulators in agricultural fields.

  8. REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK STAND, SHOWING AIRCRAFT NUMBER (319), HORIZONTAL STABILIZER, TAIL CONE AND COOLING CTS FOR THE AUXILIARY POWER UNIT (APU), MECHANIC PAUL RIDEOUT IS LOWERING THE BALANCE PANELS ON THE STABILIZERS FOR LUBRICATION AND INSPECTION. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

  9. Estimates of the occupational exposure to tenorm in the phosphoric acid production plant in Iran.

    PubMed

    Fathabadi, N; Vasheghani Farahani, M; Moradi, M; Hadadi, B

    2012-09-01

    Phosphate rock is used world wide for manufacturing phosphoric acid and several chemical fertilisers. It is known that the phosphate rock contains various concentrations of uranium, thorium, radium and their daughters. The subject of this study is the evaluation of the radiation exposure to workers in the phosphoric acid production plant due to technologically enhanced naturally occurring radioactive materials that can result from the presence of naturally occurring radioactive materials in phosphate ores used in the manufacturing of phosphoric acid. Radiation exposure due to direct gamma radiation, dust inhalation and radon gas has been investigated and external and internal doses of exposed workers have been calculated. Natural radioactivity due to (40)K, (226)Ra and (232)Th have been measured in phosphate rock, phosphogypsum, chemical fertilisers and other samples by gamma spectrometry system with a high-purity germanium. The average concentrations of (226)Ra and (40)K observed in the phosphate rock are 760 and 80 Bq kg(-1), respectively. Annual effective dose from external radiation had a mean value of ∼0.673 mSv y(-1). Dust sampling revealed greatest values in the storage area. The annual average effective dose from inhalation of long-lived airborne was 0.113 mSv y(-1). Radon gas concentrations in the processing plant and storage area were found to be of the same value as the background. In this study the estimated annual effective doses to workers were below 1 mSv y(-1).

  10. Aqueous extracts of Mozambican plants as alternative and environmentally safe acid-base indicators.

    PubMed

    Macuvele, Domingos Lusitaneo Pier; Sithole, Gerre Zebedias Samo; Cesca, Karina; Macuvele, Suzana Lília Pinare; Matsinhe, Jonas Valente

    2016-06-01

    Indicators are substances that change color as the pH of the medium. Many of these substances are dyes of synthetic origin. The mulala plant (Euclea natalensis), which roots are commonly used by rural communities for their oral hygiene, and roseira (Hibiscus rosa-sinensis), an ornamental plant, are abundant in Mozambique. Currently, synthetic acid-base indicators are most commonly used but have environmental implications and, on the other hand, are expensive products, so the demand for natural indicators started. This study investigated the applicability of aqueous extracts of H. rosa-sinensis and E. natalensis as acid-base indicators. Ground on this work, the extracts can be used as acid-base indicators. On the basis of the absorption spectroscopy in both the UV-Vis region and previous studies, it was possible to preliminarily pinpoint anthocyanins and naphthoquinones as responsible for the shifting of colors depending on the pH range of aqueous extracts of H. rosa-sinensis and E. natalensis. These natural indicators are easily accessible, inexpensive, easy to extract, environmentally safe, and locally available.

  11. Effect of aluminium uptake on physiology, phenols and amino acids in Matricaria chamomilla plants.

    PubMed

    Kovácik, Jozef; Klejdus, Borivoj; Hedbavny, Josef

    2010-06-15

    Chamomile is a widely used medicinal plant and, as observed in our previous studies, also accumulates some metals in its above-ground biomass. We therefore tested selected metabolic responses after treatments with 60 and 120 microM Al for 7 days. Shoot Al content was not elevated in comparison with control (12.3-14.1 microg g(-1) DW) while total root Al increased strongly, reaching 2680 and 4400 microg g(-1) DW in 60 and 120 microM treatments, respectively. "Intra-root" Al represented 83.6 (60 microM treatment) and 75.8% (120 microM treatment) of total root Al. Soluble proteins were not significantly affected. Free amino acids were almost unaffected in shoots while in roots the highest content was found in 60 microM Al. Ascorbate- and guaiacol-peroxidase activities were the highest in 60 microM Al-exposed roots. On the other hand, phenylalanine ammonia-lyase activity, total soluble phenols, flavonoids, a sum of 13 phenolic acids and partially two flavonols (quercetin and kaempferol) increased in the shoots. Present study has shown lower Al toxicity and unaltered shoot Al content seems to be the most positive outcome in comparison with previously tested metals (Cd, Ni and Cu). Our results indicate that phenols in shoots and free amino acids in roots are influenced by Al excess in chamomile plants. Possible mechanisms in the context of available literature are suggested and discussed.

  12. Salicylic acid-induced changes to growth and phenolic metabolism in Matricaria chamomilla plants.

    PubMed

    Kovácik, Jozef; Grúz, Jirí; Backor, Martin; Strnad, Miroslav; Repcák, Miroslav

    2009-01-01

    The influence of salicylic acid (SA) doses of 50 and 250 microM, for a period of up to 7 days, on selected physiological aspects and the phenolic metabolism of Matricaria chamomilla plants was studied. SA exhibited both growth-promoting (50 microM) and growth-inhibiting (250 microM) properties, the latter being correlated with decrease of chlorophylls, water content and soluble proteins. In terms of phenolic metabolism, it seems that the higher SA dose has a toxic effect, based on the sharp increase in phenylalanine ammonia-lyase (PAL) activity (24 h after application), which is followed by an increase in total soluble phenolics, lignin accumulation and the majority of the 11 detected phenolic acids. Guaiacol-peroxidase activity was elevated throughout the experiment in 250 microM SA-treated plants. In turn, some responses can be explained by mechanisms associated with oxidative stress tolerance; these mitigate acute SA stress (which is indicated by an increase in malondialdehyde content). However, PAL activity decreased with prolonged exposure to SA, indicating its inhibition. Accumulation of coumarin-related compounds (umbelliferone and herniarin) was not affected by SA treatments, while (Z)- and (E)-2-beta-D: -glucopyranosyloxy-4-methoxycinnamic acids increased in the 250 microM SA-treated rosettes. Free SA content in the rosettes increased significantly only in the 250 microM SA treatment, with levels tending to decrease towards the end of the experiment and the opposite trend was observed in the roots.

  13. Expanded perlite insulation selected for process piping in $80 million boric acid plant

    SciTech Connect

    Nannini, L.; Gaines, A.

    1982-03-01

    U.S. Borax's new $80 million chemical facility in Boron, California utilizes the most modern technology to produce 200,000 tons per year of boric acid that is used in texyile fiber glass, various types of heat resistant glasses, metallurgy, drugs and cosmetics. The boric acid plant contains thousands of feet of pipe to convey liquors to mixing tanks, clarifiers, crystallizers, centrifuges and other equipment for the refining process. Steel pipe lined with polyvinylidene fluoride (PVDF) was used for a major portion of the piping system to avoid corrosion problems and assure products free of contaminants. The process lines were insulated with a lightweight, asbestos-free product made of expanded perlite containing millions of air cells for low thermal conductivity, bonded together by special binders and reinforcing fibers for good compressive strength. The rigid, molded, insulation can withstand continuous and cycling temperatures to 1500/sup 0/F with minimal shrinkage, and contains less than 150 ppm chlorides to avoid stress corrosion cracking of austenitic stainless steels. The boric acid plant, which is one of the world's largest, began operations in August 1980, and the performance of the expanded perlite pipe insulation in maintaining process temperatures is considered very satisfactory. Any line leakage that occurred during start-up or normal operation has not affected the heat barrier efficiency or structural integrity of the insulation. The combined strength of the insulation and PVC jacket has prevented any serious damage to the pipe covering when struck or scraped.

  14. Pathogen-induced systemic activation of a plant defensin gene in Arabidopsis follows a salicylic acid-independent pathway.

    PubMed Central

    Penninckx, I A; Eggermont, K; Terras, F R; Thomma, B P; De Samblanx, G W; Buchala, A; Métraux, J P; Manners, J M; Broekaert, W F

    1996-01-01

    A 5-kD plant defensin was purified from Arabidopsis leaves challenged with the fungus Alternaria brassicicola and shown to possess antifungal properties in vitro. The corresponding plant defensin gene was induced after treatment of leaves with methyl jasmonate or ethylene but not with salicylic acid or 2,6-dichloroisonicotinic acid. When challenged with A. brassicicola, the levels of the plant defensin protein and mRNA rose both in inoculated leaves and in nontreated leaves of inoculated plants (systemic leaves). These events coincided with an increase in the endogenous jasmonic acid content of both types of leaves. Systemic pathogen-induced expression of the plant defensin gene was unaffected in Arabidopsis transformants (nahG) or mutants (npr1 and cpr1) affected in the salicylic acid response but was strongly reduced in the Arabidopsis mutants eln2 and col1 that are blocked in their response to ethylene and methyl jasmonate, respectively. Our results indicate that systemic pathogen-induced expression of the plant defensin gene in Arabidopsis is independent of salicylic acid but requires components of the ethylene and jasmonic acid response. PMID:8989885

  15. A Reliable and Inexpensive Method of Nucleic Acid Extraction for the PCR-Based Detection of Diverse Plant Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A reliable extraction method is described for the preparation of total nucleic acids from several plant genera for subsequent detection of plant pathogens by PCR-based techniques. By the combined use of a modified CTAB (cetyltrimethylammonium bromide) extraction protocol and a semi-automatic homogen...

  16. Rosmarinic acid is a homoserine lactone mimic produced by plants that activates a bacterial quorum-sensing regulator.

    PubMed

    Corral-Lugo, Andrés; Daddaoua, Abdelali; Ortega, Alvaro; Espinosa-Urgel, Manuel; Krell, Tino

    2016-01-05

    Quorum sensing is a bacterial communication mechanism that controls genes, enabling bacteria to live as communities, such as biofilms. Homoserine lactone (HSL) molecules function as quorum-sensing signals for Gram-negative bacteria. Plants also produce previously unidentified compounds that affect quorum sensing. We identified rosmarinic acid as a plant-derived compound that functioned as an HSL mimic. In vitro assays showed that rosmarinic acid bound to the quorum-sensing regulator RhlR of Pseudomonas aeruginosa PAO1 and competed with the bacterial ligand N-butanoyl-homoserine lactone (C4-HSL). Furthermore, rosmarinic acid stimulated a greater increase in RhlR-mediated transcription in vitro than that of C4-HSL. In P. aeruginosa, rosmarinic acid induced quorum sensing-dependent gene expression and increased biofilm formation and the production of the virulence factors pyocyanin and elastase. Because P. aeruginosa PAO1 infection induces rosmarinic acid secretion from plant roots, our results indicate that rosmarinic acid secretion is a plant defense mechanism to stimulate a premature quorum-sensing response. P. aeruginosa is a ubiquitous pathogen that infects plants and animals; therefore, identification of rosmarinic acid as an inducer of premature quorum-sensing responses may be useful in agriculture and inform human therapeutic strategies.

  17. Abscisic Acid Regulation of Root Hydraulic Conductivity and Aquaporin Gene Expression Is Crucial to the Plant Shoot Growth Enhancement Caused by Rhizosphere Humic Acids.

    PubMed

    Olaetxea, Maite; Mora, Verónica; Bacaicoa, Eva; Garnica, María; Fuentes, Marta; Casanova, Esther; Zamarreño, Angel M; Iriarte, Juan C; Etayo, David; Ederra, Iñigo; Gonzalo, Ramón; Baigorri, Roberto; García-Mina, Jose M

    2015-12-01

    The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface.

  18. Abscisic Acid Regulation of Root Hydraulic Conductivity and Aquaporin Gene Expression Is Crucial to the Plant Shoot Growth Enhancement Caused by Rhizosphere Humic Acids1

    PubMed Central

    Bacaicoa, Eva; Garnica, María; Fuentes, Marta; Casanova, Esther; Etayo, David; Ederra, Iñigo; Gonzalo, Ramón

    2015-01-01

    The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface. PMID:26450705

  19. Abscisic acid metabolizing rhizobacteria decrease ABA concentrations in planta and alter plant growth.

    PubMed

    Belimov, Andrey A; Dodd, Ian C; Safronova, Vera I; Dumova, Valentina A; Shaposhnikov, Alexander I; Ladatko, Alexander G; Davies, William J

    2014-01-01

    Although endogenous phytohormones such as abscisic acid (ABA) regulate root growth, and many rhizobacteria can modulate root phytohormone status, hitherto there have been no reports of rhizobacteria mediating root ABA concentrations and growth by metabolising ABA. Using a selective ABA-supplemented medium, two bacterial strains were isolated from the rhizosphere of rice (Oryza sativa) seedlings grown in sod-podzolic soil and assigned to Rhodococcus sp. P1Y and Novosphingobium sp. P6W using partial 16S rRNA gene sequencing and phenotypic patterns by the GEN III MicroPlate test. Although strain P6W had more rapid growth in ABA-supplemented media than strain P1Y, both could utilize ABA as a sole carbon source in batch culture. When rice seeds were germinated on filter paper in association with bacteria, root ABA concentration was not affected, but shoot ABA concentration of inoculated plants decreased by 14% (strain P6W) and 22% (strain P1Y). When tomato (Solanum lycopersicum) genotypes differing in ABA biosynthesis (ABA deficient mutants flacca - flc, and notabilis - not and the wild-type cv. Ailsa Craig, WT) were grown in gnotobiotic cultures on nutrient solution agar, rhizobacterial inoculation decreased root and/or leaf ABA concentrations, depending on plant and bacteria genotypes. Strain P6W inhibited primary root elongation of all genotypes, but increased leaf biomass of WT plants. In WT plants treated with silver ions that inhibit ethylene perception, both ABA-metabolising strains significantly decreased root ABA concentration, and strain P6W decreased leaf ABA concentration. Since these changes in ABA status also occurred in plants that were not treated with silver, it suggests that ethylene was probably not involved in regulating bacteria-mediated changes in ABA concentration. Correlations between plant growth and ABA concentrations in planta suggest that ABA-metabolising rhizobacteria may stimulate growth via an ABA-dependent mechanism.

  20. Abscisic acid and transpiration rate are involved in the response to boron toxicity in Arabidopsis plants.

    PubMed

    Macho-Rivero, Miguel Ángel; Camacho-Cristóbal, Juan José; Herrera-Rodríguez, María Begoña; Müller, Maren; Munné-Bosch, Sergi; González-Fontes, Agustín

    2016-12-09

    Boron (B) is an essential microelement for vascular plant development, but its toxicity is a major problem affecting crop yields in arid and semi-arid areas of the world. In the literature, several genes involved in abscisic acid (ABA) signalling and responses are upregulated in Arabidopsis roots after treatment with excess B. It is known that the AtNCED3 gene, which encodes a crucial enzyme for ABA biosynthesis, plays a key role in the plant response to drought stress. In this study, root AtNCED3 expression and shoot ABA content were rapidly increased in wild-type plants upon B-toxicity treatment. The Arabidopsis ABA-deficient nced3-2 mutant had higher transpiration rate, stomatal conductance and accumulated more B in their shoots than wild-type plants, facts that were associated with the lower levels of ABA in this mutant. However, in wild-type plants, B toxicity caused a significant reduction in stomatal conductance, resulting in a decreased transpiration rate. This response could be a mechanism to limit the transport of excess B from the roots to the leaves under B toxicity. In agreement with the higher transpiration rate of the nced3-2 mutant, this genotype showed an increased leaf B concentration and damage upon exposure to 5 mM B. Under B toxicity, ABA application decreased B accumulation in wild-type and nced3-2 plants. In summary, this work shows that excess B applied to the roots leads to rapid changes in AtNCED3 expression and gas exchange parameters that would contribute to restrain the B entry into the leaves, this effect being mediated by ABA.

  1. Transgenic tomato plants overexpressing tyramine N-hydroxycinnamoyltransferase exhibit elevated hydroxycinnamic acid amide levels and enhanced resistance to Pseudomonas syringae.

    PubMed

    Campos, Laura; Lisón, Purificación; López-Gresa, María Pilar; Rodrigo, Ismael; Zacarés, Laura; Conejero, Vicente; Bellés, José María

    2014-10-01

    Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.

  2. Differential effects of glyphosate and aminomethylphosphonic acid (AMPA) on photosynthesis and chlorophyll metabolism in willow plants.

    PubMed

    Gomes, Marcelo Pedrosa; Le Manac'h, Sarah Gingras; Maccario, Sophie; Labrecque, Michel; Lucotte, Marc; Juneau, Philippe

    2016-06-01

    We used a willow species (Salix miyabeana cultivar SX64) to examine the differential secondary-effects of glyphosate and aminomethylphosphonic acid (AMPA), the principal glyphosate by-product, on chlorophyll metabolism and photosynthesis. Willow plants were treated with different concentrations of glyphosate (equivalent to 0, 1.4, 2.1 and 2.8kgha(-1)) and AMPA (equivalent to 0, 0.28, 1.4 and 2.8kgha(-1)) and evaluations of pigment contents, chlorophyll fluorescence, and oxidative stress markers (hydrogen peroxide content and antioxidant enzyme activities) in leaves were performed after 12h of exposure. We observed that AMPA and glyphosate trigger different mechanisms leading to decreases in chlorophyll content and photosynthesis rates in willow plants. Both chemicals induced ROS accumulation in willow leaves although only glyphosate-induced oxidative damage through lipid peroxidation. By disturbing chlorophyll biosynthesis, AMPA induced decreases in chlorophyll contents, with consequent effects on photosynthesis. With glyphosate, ROS increases were higher than the ROS-sensitive threshold, provoking chlorophyll degradation (as seen by pheophytin accumulation) and invariable decreases in photosynthesis. Peroxide accumulation in both AMPA and glyphosate-treated plants was due to the inhibition of antioxidant enzyme activities. The different effects of glyphosate on chlorophyll contents and photosynthesis as described in the literature may be due to various glyphosate:AMPA ratios in those plants.

  3. Vermicompost humic acids modulate the accumulation and metabolism of ROS in rice plants.

    PubMed

    García, Andrés Calderín; Santos, Leandro Azevedo; de Souza, Luiz Gilberto Ambrósio; Tavares, Orlando Carlos Huertas; Zonta, Everaldo; Gomes, Ernane Tarcisio Martins; García-Mina, José Maria; Berbara, Ricardo Luis Louro

    2016-03-15

    This work aims to determine the reactive oxygen species (ROS) accumulation, gene expression, anti-oxidant enzyme activity, and derived effects on membrane lipid peroxidation and certain stress markers (proline and malondialdehyde-MDA) in the roots of unstressed and PEG-stressed rice plants associated with vermicompost humic acid (VCHA) application. The results show that the application of VCHA to the roots of unstressed rice plants caused a slight but significant increase in root ROS accumulation and the gene expression and activity of the major anti-oxidant enzymes (superoxide dismutase and peroxidase). This action did not have negative effects on root development, and an increase in both root growth and root proliferation occurred. However, the root proline and MDA concentrations and the root permeability results indicate the development of a type of mild stress associated with VCHA application. When VCHA was applied to PEG-stressed plants, a clear alleviation of the inhibition in root development linked to PEG-mediated osmotic stress was observed. This was associated with a reduction in root ROS production and anti-oxidant enzymatic activity caused by osmotic stress. This alleviation of stress caused by VCHA was also reflected as a reduction in the PEG-mediated concentration of MDA in the root as well as root permeability. In summary, the beneficial action of VCHA on the root development of unstressed or PEG-stressed rice plants clearly involves the modulation of ROS accumulation in roots.

  4. Agrochemical control of plant water use using engineered abscisic acid receptors.

    PubMed

    Park, Sang-Youl; Peterson, Francis C; Mosquna, Assaf; Yao, Jin; Volkman, Brian F; Cutler, Sean R

    2015-04-23

    Rising temperatures and lessening fresh water supplies are threatening agricultural productivity and have motivated efforts to improve plant water use and drought tolerance. During water deficit, plants produce elevated levels of abscisic acid (ABA), which improves water consumption and stress tolerance by controlling guard cell aperture and other protective responses. One attractive strategy for controlling water use is to develop compounds that activate ABA receptors, but agonists approved for use have yet to be developed. In principle, an engineered ABA receptor that can be activated by an existing agrochemical could achieve this goal. Here we describe a variant of the ABA receptor PYRABACTIN RESISTANCE 1 (PYR1) that possesses nanomolar sensitivity to the agrochemical mandipropamid and demonstrate its efficacy for controlling ABA responses and drought tolerance in transgenic plants. Furthermore, crystallographic studies provide a mechanistic basis for its activity and demonstrate the relative ease with which the PYR1 ligand-binding pocket can be altered to accommodate new ligands. Thus, we have successfully repurposed an agrochemical for a new application using receptor engineering. We anticipate that this strategy will be applied to other plant receptors and represents a new avenue for crop improvement.

  5. Australia lacks stem succulents but is it depauperate in plants with crassulacean acid metabolism (CAM)?

    PubMed

    Holtum, Joseph Am; Hancock, Lillian P; Edwards, Erika J; Crisp, Michael D; Crayn, Darren M; Sage, Rowan; Winter, Klaus

    2016-06-01

    In the flora of Australia, the driest vegetated continent, crassulacean acid metabolism (CAM), the most water-use efficient form of photosynthesis, is documented in only 0.6% of native species. Most are epiphytes and only seven terrestrial. However, much of Australia is unsurveyed, and carbon isotope signature, commonly used to assess photosynthetic pathway diversity, does not distinguish between plants with low-levels of CAM and C3 plants. We provide the first census of CAM for the Australian flora and suggest that the real frequency of CAM in the flora is double that currently known, with the number of terrestrial CAM species probably 10-fold greater. Still unresolved is the question why the large stem-succulent life - form is absent from the native Australian flora even though exotic large cacti have successfully invaded and established in Australia.

  6. Fatty acid biosynthesis redirected to medium chains in transgenic oilseed plants

    SciTech Connect

    Voelker, T.A.; Worrell, A.C.; Anderson, L.; Bleibaum, J.; Fan, C.; Hawkins, D.J.; Radke, S.E.; Davies, H.M. )

    1992-07-03

    Medium-chain fatty acids (FAs), found in storage lipids of certain plants, are an important renewable resource. Seeds of undomesticated California bay accumulate laurate (12:0), and a 12:0-acyl-carrier protein thioesterase (BTE) has been purified from this tissue. Sequencing of BTE enabled the cloning of a complementary DNA coding for a plastid-targeted preprotein. Expression of the complementary DNA in the seeds of Arabidopsis thaliana resulted in BTE activity, and medium chains accumulated at the expense of long-chain ({ge}16) FAs. Laurate became the most abundant FA species and was deposited in the storage triacylglycerols. These results demonstrate a mechanism for medium-chain FA synthesis in plants.

  7. Activation of the Jasmonic Acid Plant Defence Pathway Alters the Composition of Rhizosphere Bacterial Communities

    PubMed Central

    Carvalhais, Lilia C.; Dennis, Paul G.; Badri, Dayakar V.; Tyson, Gene W.; Vivanco, Jorge M.; Schenk, Peer M.

    2013-01-01

    Jasmonic acid (JA) signalling plays a central role in plant defences against necrotrophic pathogens and herbivorous insects, which afflict both roots and shoots. This pathway is also activated following the interaction with beneficial microbes that may lead to induced systemic resistance. Activation of the JA signalling pathway via application of methyl jasmonate (MeJA) alters the composition of carbon containing compounds released by roots, which are implicated as key determinants of rhizosphere microbial community structure. In this study, we investigated the influence of the JA defence signalling pathway activation in Arabidopsis thaliana on the structure of associated rhizosphere bacterial communities using 16S rRNA gene amplicon pyrosequencing. Application of MeJA did not directly influence bulk soil microbial communities but significant changes in rhizosphere community composition were observed upon activation of the jasmonate signalling pathway. Our results suggest that JA signalling may mediate plant-bacteria interactions in the soil upon necrotrophic pathogen and herbivorous insect attacks. PMID:23424661

  8. Mechanistic Basis for Plant Responses to Drought Stress : Regulatory Mechanism of Abscisic Acid Signaling

    NASA Astrophysics Data System (ADS)

    Miyakawa, Takuya; Tanokura, Masaru

    The phytohormone abscisic acid (ABA) plays a key role in the rapid adaptation of plants to environmental stresses such as drought and high salinity. Accumulated ABA in plant cells promotes stomatal closure in guard cells and transcription of stress-tolerant genes. Our understanding of ABA responses dramatically improved by the discovery of both PYR/PYL/RCAR as a soluble ABA receptor and inhibitory complex of a protein phospatase PP2C and a protein kinase SnRK2. Moreover, several structural analyses of PYR/PYL/RCAR revealed the mechanistic basis for the regulatory mechanism of ABA signaling, which provides a rational framework for the design of alternative agonists in future.

  9. Effect of abscisic acid and hydrogen peroxide on antioxidant enzymes in Syzygium cumini plant.

    PubMed

    Choudhary, Ramkishan; Saroha, Ajaya Eesha; Swarnkar, P L

    2012-10-01

    The present study was undertaken to study the effect of abscisic acid and hydrogen peroxide on the activities of antioxidant enzymes namely superoxide dismutase (SOD; E.C. 1.15.1.1), catalase (CAT; E.C. 1.11.1.6) and ascorbate peroxidase (APX; E.C. 1.11.1.11) in Syzygium cumini plant. The varying concentrations of ABA (2-8 mM/l) and H2O2 (2-8 mM/l) modulated enzyme activities differently. In general, some concentrations of the ABA and H2O2 stimulated the activities of all the three enzymes except that there was a dose dependent reduction in catalase activity in the plants treated with ABA.

  10. A conserved amino acid residue critical for product and substrate specificity in plant triterpene synthases

    PubMed Central

    Salmon, Melissa; Thimmappa, Ramesha B.; Minto, Robert E.; Melton, Rachel E.; O’Maille, Paul E.; Hemmings, Andrew M.; Osbourn, Anne

    2016-01-01

    Triterpenes are structurally complex plant natural products with numerous medicinal applications. They are synthesized through an origami-like process that involves cyclization of the linear 30 carbon precursor 2,3-oxidosqualene into different triterpene scaffolds. Here, through a forward genetic screen in planta, we identify a conserved amino acid residue that determines product specificity in triterpene synthases from diverse plant species. Mutation of this residue results in a major change in triterpene cyclization, with production of tetracyclic rather than pentacyclic products. The mutated enzymes also use the more highly oxygenated substrate dioxidosqualene in preference to 2,3-oxidosqualene when expressed in yeast. Our discoveries provide new insights into triterpene cyclization, revealing hidden functional diversity within triterpene synthases. They further open up opportunities to engineer novel oxygenated triterpene scaffolds by manipulating the precursor supply. PMID:27412861

  11. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress.

    PubMed

    Zhou, Lin; Xu, Hui; Mischke, Sue; Meinhardt, Lyndel W; Zhang, Dapeng; Zhu, Xujun; Li, Xinghui; Fang, Wanping

    2014-01-01

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant under drought stress is essential to develop drought-tolerant tea genotypes, along with crop management practices that can mitigate drought stress. The objective of the present investigation is evaluation of effects of exogenous ABA on the leaf proteome in tea plant exposed to drought stress. Leaf protein patterns of tea plants under simulated drought stress [(polyethylene glycol (PEG)-treated] and exogenous ABA treatment were analyzed in a time-course experiment using two-dimensional electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Among the 72 protein spots identified by MALDI-TOF MS, 16 proteins were downregulated and two were upregulated by exogenous ABA. The upregulated proteins have roles in glycolysis and photosystem II stabilization. Twenty-one protein spots were responsive to drought stress and most participate in carbohydrate and nitrogen metabolism, control of reactive oxygen species (ROS), defense, signaling or nucleic acid metabolism. The combined treatments of exogenous ABA and drought showed upregulation of 10 protein spots at 12 h and upregulation of 11 proteins at 72 h after initiation of drought stress. The results support the importance of the role that ABA plays in the tea plant during drought stress, by improving protein transport, carbon metabolism and expression of resistance proteins.

  12. Manual of phosphoric acid fuel cell power plant optimization model and computer program

    NASA Technical Reports Server (NTRS)

    Lu, C. Y.; Alkasab, K. A.

    1984-01-01

    An optimized cost and performance model for a phosphoric acid fuel cell power plant system was derived and developed into a modular FORTRAN computer code. Cost, energy, mass, and electrochemical analyses were combined to develop a mathematical model for optimizing the steam to methane ratio in the reformer, hydrogen utilization in the PAFC plates per stack. The nonlinear programming code, COMPUTE, was used to solve this model, in which the method of mixed penalty function combined with Hooke and Jeeves pattern search was chosen to evaluate this specific optimization problem.

  13. Endiandric Acid Derivatives and Other Constituents of Plants from the Genera Beilschmiedia and Endiandra (Lauraceae)

    PubMed Central

    Ndjakou Lenta, Bruno; Chouna, Jean Rodolphe; Nkeng-Efouet, Pepin Alango; Sewald, Norbert

    2015-01-01

    Plants of the Lauraceae family are widely used in traditional medicine and are sources of various classes of secondary metabolites. Two genera of this family, Beilschmiedia and Endiandra, have been the subject of numerous investigations over the past decades because of their application in traditional medicine. They are the only source of bioactive endiandric acid derivatives. Noteworthy is that their biosynthesis contains two consecutive non-enzymatic electrocyclic reactions. Several interesting biological activities for this specific class of secondary metabolites and other constituents of the two genera have been reported, including antimicrobial, enzymes inhibitory and cytotoxic properties. This review compiles information on the structures of the compounds described between January 1960 and March 2015, their biological activities and information on endiandric acid biosynthesis, with 104 references being cited. PMID:26117852

  14. Effects of ammonium on elemental nutrition of red spruce and indicator plants grown in acid soil

    SciTech Connect

    Hoelldampf, B.; Barker, A.V. )

    1993-01-01

    Decline of high elevation red spruce forests in the northeastern United States has been related to acid rain, particularly with respect to the deposition of nitrogenous materials. Ca and Mg deficiencies may be induced by input of air-borne nitrogenous nutrients into the forest ecosystem. This research investigated the effects of N nutrition on mineral nutrition of red spruce and radish, as an indicator plant, grown in acid forest soil. Red spruce and radishes in the greenhouse were treated with complete nutrient solutions with 15 mM N supplied as 0, 3.75, 7.5, 11.25, or 15 mM NH[sub 4][sup +] with the remainder being supplied as NO[sub 3][sup [minus

  15. Initial studies for the phytostabilization of a mine tailing from the Cartagena-La Union Mining District (SE Spain).

    PubMed

    Conesa, Héctor M; Faz, Angel; Arnaldos, Raquel

    2007-01-01

    Mine tailings are one of the main environmental problems in post-mining landscapes and their removal is often complicated due to their high heavy metal content and dimensions. In this sense, using plant species for in situ stabilization may be an interesting and low cost option. Moreover, there are some plant species that have adapted to these conditions and are usually present at these contaminated sites. In this study, a mine tailing located in South-East Spain was investigated in order to establish lines for further phytostabilization research. A plot sampling design was carried out in order to characterize the soil properties. In addition, two plant species that have naturally colonized some parts of the tailing, Hyparrhenia hirta and Zygophyllum fabago, were sampled, including the analyses of their respective rhizospheric soils. The results of plot soil samples showed pH values from ultra acid to slightly alkaline. The electrical conductivity values were around 4dSm(-1) in plots with vegetation and 8dS m(-1) in the plot without vegetation. Total metal concentrations were high (4000 mg kg(-1) for Pb, 9000-15000 mg kg(-1) for Zn). DTPA- and water-extractable Zn were 5% and 3% of the total, respectively. H. hirta accumulated around 150 mg kg(-1) Pb in both shoots and roots. Zn concentration was 750 mg kg(-1) in Z. fabago shoots. DTPA-extractable Zn and Cu were positively correlated to plant uptake.

  16. Amino acid transporter mutants of Arabidopsis provides evidence that a non-mycorrhizal plant acquires organic nitrogen from agricultural soil.

    PubMed

    Ganeteg, Ulrika; Ahmad, Iftikhar; Jämtgård, Sandra; Aguetoni-Cambui, Camila; Inselsbacher, Erich; Svennerstam, Henrik; Schmidt, Susanne; Näsholm, Torgny

    2017-03-01

    Although organic nitrogen (N) compounds are ubiquitous in soil solutions, their potential role in plant N nutrition has been questioned. We performed a range of experiments on Arabidopsis thaliana genetically modified to enhance or reduce root uptake of amino acids. Plants lacking expression of the Lysine Histidine Transporter 1 (LHT1) displayed significantly lower contents of (13) C and (15) N label and of U-(13) C5 ,(15) N2 L-glutamine, as determined by liquid chromatography-mass spectrometry when growing in pots and supplied with dually labelled L-glutamine compared to wild type plants and LHT1-overexpressing plants. Slopes of regressions between accumulation of (13) C-labelled carbon and (15) N-labelled N were higher for LHT1-overexpressing plants than wild type plants, while plants lacking expression of LHT1 did not display a significant regression between the two isotopes. Uptake of labelled organic N from soil tallied with that of labelled ammonium for wild type plants and LHT1-overexpressing plants but was significantly lower for plants lacking expression of LHT1. When grown on agricultural soil plants lacking expression of LHT1 had the lowest, and plants overexpressing LHT1 the highest C/N ratios and natural δ(15) N abundance suggesting their dependence on different N pools. Our data show that LHT1 expression is crucial for plant uptake of organic N from soil.

  17. Histochemical Compartmentation of Photosynthesis in the Crassulacean Acid Metabolism Plant Crassula falcata1

    PubMed Central

    Springer, Stefan A.; Outlaw, William H.

    1988-01-01

    The succulent leaf of the obligate Crassulacean acid metabolism plant Crassula falcata comprises two distinct types of parenchyma. The peripheral tissue is dark green, whereas the central tissue is relatively colorless. We have investigated whether the conventional interpretation of Crassulacean acid metabolism—simply, temporal separation of light and dark CO2 fixation within individual cells—is sufficient. Ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) and chlorophyll, indicating the photosynthetic-carbon-reduction pathway, were concentrated in peripheral tissue. Specific activities of P-enolpyruvate carboxylase (4.1.1.31) and of NAD+-malic enzyme (1.1.1.39), indicating capacity for dark CO2 fixation and release, respectively, were high in both types of parenchyma. Measured directly as malic acid decline at the beginning of the photoperiod, CO2 “storage” occurred in both tissues. These data indicate that there is a spatial component to Crassulacean acid metabolism in C. falcata. Images Fig. 1 Fig. 2 Fig. 5 PMID:16666360

  18. How Very-Long-Chain Fatty Acids Could Signal Stressful Conditions in Plants?

    PubMed Central

    De Bigault Du Granrut, Antoine; Cacas, Jean-Luc

    2016-01-01

    Although encountered in minor amounts in plant cells, very-long-chain fatty acids exert crucial functions in developmental processes. When their levels are perturbed by means of genetic approaches, marked phenotypic consequences that range from severe growth retardation to embryo lethality was indeed reported. More recently, a growing body of findings has also accumulated that points to a potential role for these lipids as signals in governing both biotic and abiotic stress outcomes. In the present work, we discuss the latter theory and explore the ins and outs of very-long-chain fatty acid-based signaling in response to stress, with an attempt to reconcile two supposedly antagonistic parameters: the insoluble nature of fatty acids and their signaling function. To explain this apparent dilemma, we provide new interpretations of pre-existing data based on the fact that sphingolipids are the main reservoir of very-long-chain fatty acids in leaves. Thus, three non-exclusive, molecular scenarii that involve these lipids as membrane-embedded and free entities are proposed. PMID:27803703

  19. Kinetics of sulfuric acid leaching of cadmium from Cd-Ni zinc plant residues.

    PubMed

    Safarzadeh, Mohammad Sadegh; Moradkhani, Davood; Ojaghi-Ilkhchi, Mehdi

    2009-04-30

    Cd-Ni filtercakes are produced continuously at the third purification step in the electrolytic production of zinc in the National Iranian Lead and Zinc Company (NILZ) in northwestern Iran. In this research, the dissolution kinetics of cadmium from Cd-Ni residues produced in NILZ plant has been investigated. Hence, the effects of temperature, sulfuric acid concentration, particle size and stirring speed on the kinetics of cadmium dissolution in sulfuric acid were studied. The dissolution kinetics at 25-55 degrees C and tacid concentration, solid/liquid ratio and particle size were also achieved. The rate of reaction at first 5 min based on diffusion-controlled process can be expressed by a semi-empirical equation as:It was determined that the dissolution rate increased with increasing sulfuric acid concentration and decreasing particle size.

  20. Faun tail nevus

    PubMed Central

    Yamini, M.; Sridevi, K. S.; Babu, N. Prasanna; Chetty, Nanjappa G.

    2011-01-01

    Faun tail nevus is a posterior midline cutaneous lesion of importance to dermatologists as it could be a cutaneous marker for its underlying spine and spinal cord anomaly. We report a 13-year-old girl with excessive hair growth over the lumbosacral region since birth. There was associated spinal anomaly with no neurological manifestation affecting the lower spinal cord. The diagnosis was made on clinical basis. The patient reported for cosmetic disability. This case is reported for its clinical importance. PMID:23130210

  1. Faun tail nevus.

    PubMed

    Yamini, M; Sridevi, K S; Babu, N Prasanna; Chetty, Nanjappa G

    2011-01-01

    Faun tail nevus is a posterior midline cutaneous lesion of importance to dermatologists as it could be a cutaneous marker for its underlying spine and spinal cord anomaly. We report a 13-year-old girl with excessive hair growth over the lumbosacral region since birth. There was associated spinal anomaly with no neurological manifestation affecting the lower spinal cord. The diagnosis was made on clinical basis. The patient reported for cosmetic disability. This case is reported for its clinical importance.

  2. Transcriptome analysis highlights changes in the leaves of maize plants cultivated in acidic soil containing toxic levels of Al(3+).

    PubMed

    Mattiello, Lucia; Begcy, Kevin; da Silva, Felipe Rodrigues; Jorge, Renato A; Menossi, Marcelo

    2014-12-01

    Soil acidity limits crop yields worldwide and is a common result of aluminum (Al) phytotoxicity, which is known to inhibit root growth. Here, we compared the transcriptome of leaves from maize seedlings grown under control conditions (soil without free Al) and under acidic soil containing toxic levels of Al. This study reports, for the first time, the complex transcriptional changes that occur in the leaves of maize plants grown in acidic soil with phytotoxic levels of Al. Our data indicate that 668 genes were differentially expressed in the leaves of plants grown in acidic soil, which is significantly greater than that observed in our previous work with roots. Genes encoding TCA cycle enzymes were upregulated, although no specific transporter of organic acids was differentially expressed in leaves. We also provide evidence for positive roles for auxin and brassinosteroids in Al tolerance, whereas gibberellin and jasmonate may have negative roles. Our data indicate that plant responses to acidic soil with high Al content are not restricted to the root; tolerance mechanisms are also displayed in the aerial parts of the plant, thus indicating that the entire plant responds to stress.

  3. Distribution of triterpene acids and their derivatives in organs of cowberry (Vaccinium vitis-idaea L.) plant.

    PubMed

    Szakiel, Anna; Mroczek, Agnieszka

    2007-01-01

    Wild berries of the genus Vaccinium have become increasingly popular in human health promotion due to their nutritional and medicinal properties. Some striking divergence of opinion about the content of triterpenoids in these plants still exists, meanwhile, this very large class of natural isoprenoids exhibits a wide range of biological activities and hence is of growing research interest. An investigation of triterpenoidal constituents from the cowberry (Vaccinium vitis-idaea L.) plant led to the isolation of two isomeric acids: oleanolic and ursolic and the occurrence of their derivatives in this plant was demonstrated for the first time. Free triterpene acids as well as small amounts of their bound forms (presumable glycosides and glycoside esters) occur in fruits and the vegetative part of the plant, however, in various amounts and different ratios. The total content of both acids was the highest in organs regarded as traditional herbal resources, namely fruits and leaves (1 and 0.6% of dry mass, respectively), whereas it was markedly lower in stems and rhizomes. However, the rhizomes were in turn the plant organ containing relatively the highest amount of the bound forms of both acids (0.01% of dry mass). Ursolic acid was dominant in the whole plant, but the ratio of oleanolic to ursolic acid was significantly different in individual organs, decreasing from the upper (fruits 1:2.4, leaves 1:2) to the lower (stems 1:3.5, rhizomes 1:5.2) parts of the plant. This pattern of distribution of triterpenoids in the plant may have an important physiological and ecological meaning.

  4. Routine sample preparation and HPLC analysis for ascorbic acid (vitamin C) determination in wheat plants and Arabidopsis leaf tissues.

    PubMed

    Szalai, Gabriella; Janda, T; Pál, Magda

    2014-06-01

    Plants have developed various mechanisms to protect themselves against oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid. There is thus a need for a rapid, sensitive method for the analysis of the reduced and oxidised forms of ascorbic acid in crop plants. In this paper a simple, economic, selective, precise and stable HPLC method is presented for the detection of ascorbate in plant tissue. The sensitivity, the short retention time and the simple isocratic elution mean that the method is suitable for the routine quantification of ascorbate in a high daily sample number. The method has been found to be better than previously reported methods, because of the use of an economical, readily available mobile phase, UV detection and the lack of complicated extraction procedures. The method has been tested on Arabidopsis plants with different ascorbate levels and on wheat plants during Cd stress.

  5. Structural evolution of differential amino acid effector regulation in plant chorismate mutases.

    PubMed

    Westfall, Corey S; Xu, Ang; Jez, Joseph M

    2014-10-10

    Chorismate mutase converts chorismate into prephenate for aromatic amino acid biosynthesis. To understand the molecular basis of allosteric regulation in the plant chorismate mutases, we analyzed the three Arabidopsis thaliana chorismate mutase isoforms (AtCM1-3) and determined the x-ray crystal structures of AtCM1 in complex with phenylalanine and tyrosine. Functional analyses show a wider range of effector control in the Arabidopsis chorismate mutases than previously reported. AtCM1 is activated by tryptophan with phenylalanine and tyrosine acting as negative effectors; however, tryptophan, cysteine, and histidine activate AtCM3. AtCM2 is a nonallosteric form. The crystal structure of AtCM1 in complex with tyrosine and phenylalanine identifies differences in the effector sites of the allosterically regulated yeast enzyme and the other two Arabidopsis isoforms. Site-directed mutagenesis of residues in the effector site reveals key features leading to differential effector regulation in these enzymes. In AtCM1, mutations of Gly-213 abolish allosteric regulation, as observed in AtCM2. A second effector site position, Gly-149 in AtCM1 and Asp-132 in AtCM3, controls amino acid effector specificity in AtCM1 and AtCM3. Comparisons of chorismate mutases from multiple plants suggest that subtle differences in the effector site are conserved in different lineages and may lead to specialized regulation of this branch point enzyme.

  6. Connecting Proline and γ-Aminobutyric Acid in Stressed Plants through Non-Enzymatic Reactions

    PubMed Central

    Signorelli, Santiago; Dans, Pablo D.; Coitiño, E. Laura; Borsani, Omar; Monza, Jorge

    2015-01-01

    The accumulation of proline (Pro) in plants exposed to biotic/abiotic stress is a well-documented and conserved response in most vegetal species. Stress conditions induce the overproduction of reactive oxygen species which can lead to cellular damage. In vitro assays have shown that enzyme inactivation by hydroxyl radicals (·OH) can be avoided in presence of Pro, suggesting that this amino acid could act as an ·OH scavenger. We applied Density Functional Theory coupled with a polarizable continuum model to elucidate how Pro reacts with ·OH. In this work we suggest that Pro reacts favourably with ·OH by H–abstraction on the amine group. This reaction produces the spontaneous decarboxylation of Pro leading to the formation of pyrrolidin-1-yl. In turn, pyrrolidin-1-yl can easily be converted to Δ1-pyrroline, the substrate of the enzyme Δ1-pyrroline dehydrogenase, which produces γ-aminobutyric acid (GABA). GABA and Pro are frequently accumulated in stressed plants and several protective roles have been assigned to these molecules. Thereby we present an alternative non-enzymatic way to synthetize GABA under oxidative stress. Finally this work sheds light on a new beneficial role of Pro accumulation in the maintenance of photosynthetic activity. PMID:25775459

  7. Connecting proline and γ-aminobutyric acid in stressed plants through non-enzymatic reactions.

    PubMed

    Signorelli, Santiago; Dans, Pablo D; Coitiño, E Laura; Borsani, Omar; Monza, Jorge

    2015-01-01

    The accumulation of proline (Pro) in plants exposed to biotic/abiotic stress is a well-documented and conserved response in most vegetal species. Stress conditions induce the overproduction of reactive oxygen species which can lead to cellular damage. In vitro assays have shown that enzyme inactivation by hydroxyl radicals (·OH) can be avoided in presence of Pro, suggesting that this amino acid could act as an ·OH scavenger. We applied Density Functional Theory coupled with a polarizable continuum model to elucidate how Pro reacts with ·OH. In this work we suggest that Pro reacts favourably with ·OH by H-abstraction on the amine group. This reaction produces the spontaneous decarboxylation of Pro leading to the formation of pyrrolidin-1-yl. In turn, pyrrolidin-1-yl can easily be converted to Δ1-pyrroline, the substrate of the enzyme Δ1-pyrroline dehydrogenase, which produces γ-aminobutyric acid (GABA). GABA and Pro are frequently accumulated in stressed plants and several protective roles have been assigned to these molecules. Thereby we present an alternative non-enzymatic way to synthetize GABA under oxidative stress. Finally this work sheds light on a new beneficial role of Pro accumulation in the maintenance of photosynthetic activity.

  8. Eliminating aluminum toxicity in an acid sulfate soil for rice cultivation using plant growth promoting bacteria.

    PubMed

    Panhwar, Qurban Ali; Naher, Umme Aminun; Radziah, Othman; Shamshuddin, Jusop; Razi, Ismail Mohd

    2015-02-20

    Aluminum toxicity is widely considered as the most important limiting factor for plants growing in acid sulfate soils. A study was conducted in laboratory and in field to ameliorate Al toxicity using plant growth promoting bacteria (PGPB), ground magnesium limestone (GML) and ground basalt. Five-day-old rice seedlings were inoculated by Bacillus sp., Stenotrophomonas maltophila, Burkholderia thailandensis and Burkholderia seminalis and grown for 21 days in Hoagland solution (pH 4.0) at various Al concentrations (0, 50 and 100 μM). Toxicity symptoms in root and leaf were studied using scanning electron microscope. In the field, biofertilizer (PGPB), GML and basalt were applied (4 t·ha-1 each). Results showed that Al severely affected the growth of rice. At high concentrations, the root surface was ruptured, leading to cell collapse; however, no damages were observed in the PGPB inoculated seedlings. After 21 days of inoculation, solution pH increased to >6.0, while the control treatment remained same. Field study showed that the highest rice growth and yield were obtained in the bio-fertilizer and GML treatments. This study showed that Al toxicity was reduced by PGPB via production of organic acids that were able to chelate the Al and the production of polysaccharides that increased solution pH. The release of phytohormones further enhanced rice growth that resulted in yield increase.

  9. Uranium and thorium leached from uranium mill tailing of Guangdong Province, China and its implication for radiological risk.

    PubMed

    Wang, J; Liu, J; Zhu, L; Qi, J Y; Chen, Y H; Xiao, T F; Fu, S M; Wang, C L; Li, J W

    2012-11-01

    The paper focused on the leaching behaviour of uranium (U) and thorium (Th) from uranium mill tailing collected from the Uranium Mill Plant in Northern Guangdong Province, China. Distilled water (pH 6) and sulphuric acid solution (pH 4 and 3) were used as solvent for the leaching over 22 weeks. It was found that the cumulative leach fraction from the mill tailing was 0.1, 0.1 and 0.7 % for U release, and overall 0.01 % for Th release, using distilled water, sulphuric acid solution of pH 4 and pH 3 as leaching agents, respectively. The results indicate that (1) the release of U and Th in uranium mill tailing is a slow and long-term process; (2) surface dissolution is the main mechanism for the release of U and Th when sulphuric acid solution of pH 3 is employed as the leaching agent; (3) both U and Th are released by diffusion when using sulphuric acid solution of pH 4 as the leaching agent and (4) U is released by surface dissolution, while Th is released by diffusion when using distilled water as the leaching agent. The implication for radiological risk in the real environment was also discussed.

  10. Gene cloning of an efficiency oleate hydratase from Stenotrophomonas nitritireducens for polyunsaturated fatty acids and its application in the conversion of plant oils to 10-hydroxy fatty acids.

    PubMed

    Kang, Woo-Ri; Seo, Min-Ju; Shin, Kyung-Chul; Park, Jin-Byung; Oh, Deok-Kun

    2017-01-01

    Hydroxy fatty acids are used as precursors of lactones and dicarboxylic acids, as starting materials of polymers, and as additives in coatings and paintings. Stenotrophomonas nitritireducens efficiently converts cis-9 polyunsaturated fatty acids (PUFAs) to 10-hydroxy fatty acids. However, gene encoding enzyme involved in this conversion has not been identified to date. We purified a putative fatty acid double-bond hydratase from S. nitritireducens by ultrafiltration and HiPrep DEAE FF and Resource Q ion exchange chromatographies. Peptide sequences of the purified enzyme were obtained by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis. Sequence of the partial gene encoding this putative fatty acid double-bond hydratase was determined by degenerate polymerase chain reaction (PCR) based on the peptide sequences. The remaining gene sequence was identified by rapid amplification of cDNA ends using cDNA of S. nitritireducens as a template, and the full-length gene was cloned subsequently. The expressed enzyme was identified as an oleate hydratase by determining its kinetic parameters toward unsaturated fatty acids. S. nitritireducens oleate hydratase showed higher activity toward PUFAs compared with other available oleate hydratases. This suggested that the enzyme could be used effectively to convert plant oils to 10-hydroxy fatty acids because these oils contained unsaturated fatty acids such as oleic acid (OA) and linoleic acid (LA) and PUFAs such as α-linolenic acid and/or γ-linolenic acid. The enzyme converted soybean oil and perilla seed oil hydrolyzates containing 10 mM total unsaturated fatty acids, including OA, LA, and ALA, to 8.87 and 8.70 mM total 10-hydroxy fatty acids, respectively, in 240 min. To our knowledge, this is the first study on the biotechnological conversion of PUFA-containing oils to hydroxy fatty acids. Biotechnol. Bioeng. 2017;114: 74-82. © 2016 Wiley Periodicals, Inc.

  11. Stimulation of plant plasma membrane Ca2+-ATPase activity by acidic phospholipids.

    PubMed

    Bonza, Maria Cristina; Luoni, Laura; De Michelis, Maria Ida

    2001-07-01

    The effect of phospholipids on the activity of the plasma membrane (PM) Ca2+-ATPase was evaluated in PM isolated from germinating radish (Raphanus sativus L. cv. Tondo Rosso Quarantino) seeds after removal of endogenous calmodulin (CaM) by washing the PM vesicles with EDTA. Acidic phospholipids stimulated the basal Ca2+-ATPase activity in the following order of efficiency: phosphatidylinositol 4,5-diphosphate (PIP2) approximately phosphatidylinositol 4-monophosphate>phosphatidylinositol approximately phosphatidylserine approximately phosphatidic acid. Neutral phospholipids as phosphatidylcholine and phosphatidylethanolamine were essentially ineffective. When the assays were performed in the presence of optimal free Ca2+ concentrations (10 &mgr;M) acidic phospholipids did not affect the Ca2+-ATPase activated by CaM or by a controlled trypsin treatment of the PM, which cleaved the CaM-binding domain of the enzyme. Analysis of the dependence of Ca2+-ATPase activity on free Ca2+ concentration showed that acidic phospholipids increased Vmax and lowered the apparent Km for free Ca2+ below the value measured upon tryptic cleavage of the CaM-binding domain; in particular, PIP2 was shown to lower the apparent Km for free Ca2+ of the Ca2+-ATPase also in trypsin-treated PM. These results indicate that acidic phospholipids activate the plant PM Ca2+-ATPase through a mechanism only partially overlapping that of CaM, and thus involving a phospholipid-binding site in the Ca2+-ATPase distinct from the CaM-binding domain. The physiological implications of these results are discussed.

  12. Peltophorum africanum, a traditional South African medicinal plant, contains an anti HIV-1 constituent, betulinic acid.

    PubMed

    Theo, Andros; Masebe, Tracy; Suzuki, Yasuhiro; Kikuchi, Haruhisa; Wada, Shoko; Obi, Chikwelu Larry; Bessong, Pascal Obong; Usuzawa, Motoki; Oshima, Yoshiteru; Hattori, Toshio

    2009-02-01

    The biodiversity of medicinal plants in South Africa makes them rich sources of leading compounds for the development of novel drugs. Peltophorum africanum (Fabaceae) is a deciduous tree widespread in South Africa. The stem bark has been traditionally employed to treat diarrhoea, dysentery, sore throat, wounds, human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS), venereal diseases and infertility. To evaluate these ethnobotanical clues and isolate lead compounds, butanol and ethyl acetate extracts of the stem bark were screened for their inhibitory activities against HIV-1 using MAGI CCR5+ cells, which are derived from HeLa cervical cancer cells and express HIV receptor CD4, a chemokine receptor CCR5 and HIV-LTR-beta- galactosidase. Bioassay-guided fractionation using silica gel chromatography was also conducted. The ethyl acetate and butanol extracts of the stem bark of Peltophorum africanum showed inhibitory activity against HIV-1, CXCR4 (X4) and CCR5 (R5) tropic viruses. The ethyl acetate and butanol extracts yielded previously reported anti-HIV compounds, (+)-catechin, a flavonoid, and bergenin, a C-galloylglycoside, respectively. Furthermore, we identified betulinic acid from the ethyl acetate fraction for the first time. The fractions, which contained betulinic acid, showed the highest selective index. We therefore describe the presence of betulinic acid, a not well-known anti-HIV compound, in an African medicinal herb, which has been used for therapy, and claim that betulinic acid is the predominant anti-HIV-1 constituent of Peltophorum africanum. These data suggest that betulinic acid and its analogues could be used as potential therapeutics for HIV-1 infection.

  13. Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

    PubMed Central

    Mohd Sairazi, Nur Shafika; Sirajudeen, K. N. S.; Asari, Mohd Asnizam; Muzaimi, Mustapha; Mummedy, Swamy; Sulaiman, Siti Amrah

    2015-01-01

    Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS). In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA). KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration. PMID:26793262

  14. Exogenous salicylic acid alleviates the toxicity of chlorpyrifos in wheat plants (Triticum aestivum).

    PubMed

    Wang, Caixia; Zhang, Qingming

    2017-03-01

    The role of exogenous salicylic acid (SA) in protecting wheat plants (Triticum aestivum) from contamination by the insecticide chlorpyrifos was investigated in this study. The wheat plants were grown in soils with different concentrations (5, 10, 20, and 40mgkg(-1)) of chlorpyrifos. When the third leaf emerged, the wheat leaves were sprayed with 1, 2, 4, 8, and 16mgL(-1) of SA once a day for 6 days. The results showed that wheat exposed to higher concentrations of chlorpyrifos (≥20mgkg(-1)) caused declines in growth and chlorophyll content and altered the activities of a series of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). Interestingly, treatments with different concentrations of SA mitigated the stress generated by chlorpyrifos and improved the measured parameters to varying degrees. Furthermore, a reverse transcription and quantitative PCR experiment revealed that the activities of SOD and CAT can be regulated by their target gene in wheat when treated with SA. We also found that SA is able to block the accumulation of chlorpyrifos in wheat. However, the effect of SA was related to its concentration. In this study, the application of 2mgL(-1) of SA had the greatest ameliorating effect on chlorpyrifos toxicity in wheat plants.

  15. Analysis of glyphosate and aminomethylphosphonic acid in water, plant materials and soil.

    PubMed

    Koskinen, William C; Marek, LeEtta J; Hall, Kathleen E

    2016-03-01

    There is a need for simple, fast, efficient and sensitive methods of analysis for glyphosate and its degradate aminomethylphosphonic acid (AMPA) in diverse matrices such as water, plant materials and soil to facilitate environmental research needed to address the continuing concerns related to increasing glyphosate use. A variety of water-based solutions have been used to extract the chemicals from different matrices. Many methods require extensive sample preparation, including derivatization and clean-up, prior to analysis by a variety of detection techniques. This review summarizes methods used during the past 15 years for analysis of glyphosate and AMPA in water, plant materials and soil. The simplest methods use aqueous extraction of glyphosate and AMPA from plant materials and soil, no derivatization, solid-phase extraction (SPE) columns for clean-up, guard columns for separation and confirmation of the analytes by mass spectrometry and quantitation using isotope-labeled internal standards. They have levels of detection (LODs) below the regulatory limits in North America. These methods are discussed in more detail in the review.

  16. Salicylic acid-induced superoxide generation catalyzed by plant peroxidase in hydrogen peroxide-independent manner

    PubMed Central

    Kimura, Makoto; Kawano, Tomonori

    2015-01-01

    It has been reported that salicylic acid (SA) induces both immediate spike and long lasting phases of oxidative burst represented by the generation of reactive oxygen species (ROS) such as superoxide anion radical (O2•−). In general, in the earlier phase of oxidative burst, apoplastic peroxidase are likely involved and in the late phase of the oxidative burst, NADPH oxidase is likely involved. Key signaling events connecting the 2 phases of oxidative burst are calcium channel activation and protein phosphorylation events. To date, the known earliest signaling event in response to exogenously added SA is the cell wall peroxidase-catalyzed generation of O2•− in a hydrogen peroxide (H2O2)-dependent manner. However, this model is incomplete since the source of the initially required H2O2 could not be explained. Based on the recently proposed role for H2O2-independent mechanism for ROS production catalyzed by plant peroxidases (Kimura et al., 2014, Frontiers in Plant Science), we hereby propose a novel model for plant peroxidase-catalyzed oxidative burst fueled by SA. PMID:26633563

  17. Abscisic-acid-dependent basic leucine zipper (bZIP) transcription factors in plant abiotic stress.

    PubMed

    Banerjee, Aditya; Roychoudhury, Aryadeep

    2017-01-01

    One of the major causes of significant crop loss throughout the world is the myriad of environmental stresses including drought, salinity, cold, heavy metal toxicity, and ultraviolet-B (UV-B) rays. Plants as sessile organisms have evolved various effective mechanism which enable them to withstand this plethora of stresses. Most of such regulatory mechanisms usually follow the abscisic-acid (ABA)-dependent pathway. In this review, we have primarily focussed on the basic leucine zipper (bZIP) transcription factors (TFs) activated by the ABA-mediated signalosome. Upon perception of ABA by specialized receptors, the signal is transduced via various groups of Ser/Thr kinases, which phosphorylate the bZIP TFs. Following such post-translational modification of TFs, they are activated so that they bind to specific cis-acting sequences called abscisic-acid-responsive elements (ABREs) or GC-rich coupling elements (CE), thereby influencing the expression of their target downstream genes. Several in silico techniques have been adopted so far to predict the structural features, recognize the regulatory modification sites, undergo phylogenetic analyses, and facilitate genome-wide survey of TF under multiple stresses. Current investigations on the epigenetic regulation that controls greater accessibility of the inducible regions of DNA of the target gene to the bZIP TFs exclusively under stress situations, along with the evolved stress memory responses via genomic imprinting mechanism, have been highlighted. The potentiality of overexpression of bZIP TFs, either in a homologous or in a heterologous background, in generating transgenic plants tolerant to various abiotic stressors have also been addressed by various groups. The present review will provide a coherent documentation on the functional characterization and regulation of bZIP TFs under multiple environmental stresses, with the major goal of generating multiple-stress-tolerant plant cultivars in near future.

  18. Cadmium and nickel uptake are differentially modulated by salicylic acid in Matricaria chamomilla plants.

    PubMed

    Kovácik, Jozef; Grúz, Jirí; Hedbavny, Josef; Klejdus, Borivoj; Strnad, Miroslav

    2009-10-28

    Chamomile (Matricaria chamomilla) is a widely used medicinal plant which also accumulates heavy metals in its above-ground organs. We investigated the effect of the important plant signaling molecule, salicylic acid (SA), on the accumulation of Ni or Cd, by exposing plants over 7 days to 60 microM solutions of individual heavy metals with or without 50 microM SA. Special emphasis was focused on phenolic metabolism-related parameters, not only because of their importance for growth and stress tolerance but also because phenolics are potent antioxidants in human diet. In combined treatments, SA stimulated an increase in soluble proteins of roots and reduced their water content. SA reduced total Cd in the shoot and increased Ni. Total and "intraroot" Ni decreased in Ni + SA treatment, while in the case of Cd, only "intraroot" content decreased in Cd + SA treatment, being correlated with cell wall-bound phenolic acids and lignin. SA was strongly accumulated in roots from the Ni + SA treatment, being correlated with an increase in hydrogen peroxide. In both Cd + SA and Ni + SA treatments, SA enhanced phenylalanine ammonia-lyase activity and accumulation of total soluble phenols, particularly in the roots. Here, we report for the first time that soluble phenols may be involved in Cd shoot-to-root translocation. In the case of Ni, it seems that phenols serve as a root barrier in order to prevent Ni from reaching the above-ground organs. The effects of SA on phenolic metabolism, and the signaling role of ROS in the accumulation of phenols, are discussed.

  19. Removal of sulfuric acid mist from lead-acid battery plants by coal fly ash-based sorbents.

    PubMed

    Shu, Yuehong; Wei, Xiangyu; Fang, Yu; Lan, Bingyan; Chen, Hongyu

    2015-04-09

    Sorbents from coal fly ash (CFA) activated by NaOH, CaO and H2O were prepared for H2SO4 mist removal from lead-acid battery plants. The effects of parameters including temperature, time, the ratios of CFA/activator and water/solid during sorbent preparation were investigated. It is found that the synthesized sorbents exhibit much higher removal capacity for H2SO4 mist when compared with that of raw coal fly ash and CaO except for H2O activated sorbent and this sorbent was hence excluded from the study because of its low capacity. The H2SO4 mist removal efficiency increases with the increasing of preparation time length and temperature. In addition, the ratios of CFA/activator and water/solid also impact the removal efficiency, and the optimum preparation conditions are identified as: a water/solid ratio of 10:1 at 120 °C for 10h, a CFA:CaO weight ratio of 10:1, and a NaOH solution concentration of 3 mol/L. The formation of rough surface structure and an increased surface area after NaOH/CaO activation favor the sorption of H2SO4 mist and possible sorption mechanisms might be electrostatic attractions and chemical precipitation between the surface of sorbents and H2SO4 mist.

  20. Antioxidant activity of phenolic compounds added to a functional emulsion containing omega-3 fatty acids and plant sterol esters.

    PubMed

    Espinosa, Raquel Rainho; Inchingolo, Raffaella; Alencar, Severino Matias; Rodriguez-Estrada, Maria Teresa; Castro, Inar Alves

    2015-09-01

    The effect of eleven compounds extracted from red propolis on the oxidative stability of a functional emulsion was evaluated. Emulsions prepared with Echium oil as omega 3 (ω-3 FA) source, containing 1.63 g/100mL of α-linolenic acid (ALA), 0.73 g/100 mL of stearidonic acid (SDA) and 0.65 g/100mL of plant sterol esters (PSE) were prepared without or with phenolic compounds (vanillic acid, caffeic acid, trans-cinnamic acid, 2,4-dihydroxycinnamic acid, p-coumaric acid, quercetin, trans-ferulic acid, trans,trans-farnesol, rutin, gallic acid or sinapic acid). tert-Butylhydroquinone and a mixture containing ascorbic acid and FeSO4 were applied as negative and positive controls of the oxidation. Hydroperoxide, thiobarbituric acid reactive substances (TBARS), malondialdehyde and phytosterol oxidation products (POPs) were evaluated as oxidative markers. Based on hydroperoxide and TBARS analysis, sinapic acid and rutin (200 ppm) showed the same antioxidant activity than TBHQ, representing a potential alternative as natural antioxidant to be applied in a functional emulsion containing ω-3 FA and PSE.

  1. Accumulation of very-long-chain fatty acids in membrane glycerolipids is associated with dramatic alterations in plant morphology.

    PubMed Central

    Millar, A A; Wrischer, M; Kunst, L

    1998-01-01

    Transgenic Arabidopsis plants overexpressing the Arabidopsis FATTY ACID ELONGATION1 gene under the control of the 35S promoter from cauliflower mosaic virus accumulated very-long-chain fatty acids (VLCFAs) throughout the plant. In some transformants, C20 and C22 VLCFAs accounted for >30% of the total fatty acids, accumulating at the expense of C16 and C18 fatty acids. These C20 and C22 fatty acids were incorporated into all of the major membrane glycerolipid classes. Plants with a high VLCFA content displayed a dramatically altered morphology, which included the failure of flowering shoots to elongate, a modified spatial pattern of siliques, an altered floral phenotype, and a large accumulation of anthocyanins. In addition, these plants also exhibited a unique alteration of the chloroplast membrane structure. We discuss a possible role for VLCFAs in establishing the shape/curvature of the membranes, which in turn may affect the shape of the cell and ultimately that of the whole plant. PMID:9811796

  2. Metabolic engineering of medium-chain fatty acid biosynthesis in Nicotiana benthamiana plant leaf lipids

    PubMed Central

    Reynolds, Kyle B.; Taylor, Matthew C.; Zhou, Xue-Rong; Vanhercke, Thomas; Wood, Craig C.; Blanchard, Christopher L.; Singh, Surinder P.; Petrie, James R.

    2015-01-01

    Various research groups are investigating the production of oil in non-seed biomass such as leaves. Recently, high levels of oil accumulation have been achieved in plant biomass using a combination of biotechnological approaches which also resulted in significant changes to the fatty acid composition of the leaf oil. In this study, we were interested to determine whether medium-chain fatty acids (MCFA) could be accumulated in leaf oil. MCFA are an ideal feedstock for biodiesel and a range of oleochemical products including lubricants, coatings, and detergents. In this study, we explore the synthesis, accumulation, and glycerolipid head-group distribution of MCFA in leaves of Nicotiana benthamiana after transient transgenic expression of C12:0-, C14:0-, and C16:0-ACP thioesterase genes. We demonstrate that the production of these MCFA in leaf is increased by the co-expression of the WRINKLED1 (WRI1) transcription factor, with the lysophosphatidic acid acyltransferase (LPAAT) from Cocos nucifera being required for the assembly of tri-MCFA TAG species. We also demonstrate that the newly-produced MCFA are incorporated into the triacylglycerol of leaves in which WRI1 + diacylglycerol acyltransferase1 (DGAT1) genes are co-expressed for increased oil accumulation. PMID:25852716

  3. A national discharge load of perfluoroalkyl acids derived from industrial wastewater treatment plants in Korea.

    PubMed

    Kim, Hee-Young; Seok, Hyun-Woo; Kwon, Hye-Ok; Choi, Sung-Deuk; Seok, Kwang-Seol; Oh, Jeong Eun

    2016-09-01

    Levels of 11 perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were measured in wastewater (influent and effluent) and sludge samples collected from 25 industrial wastewater treatment plants (I-WWTPs) in five industrial sectors (chemicals, electronics, metals, paper, and textiles) in South Korea. The highest ∑11PFAAs concentrations were detected in the influent and effluent from the paper (median: 411ng/L) and textile (median: 106ng/L) industries, and PFOA and PFOS were the predominant PFAAs (49-66%) in wastewater. Exceptionally high levels of PFAAs were detected in the sludge associated with the electronics (median: 91.0ng/g) and chemical (median: 81.5ng/g) industries with PFOS being the predominant PFAA. The discharge loads of 11 PFAAs from I-WWTP were calculated that total discharge loads for the five industries were 0.146ton/yr. The textile industry had the highest discharge load with 0.055ton/yr (PFOA: 0.039ton/yr, PFOS: 0.010ton/yr). Municipal wastewater contributed more to the overall discharge of PFAAs (0.489ton/yr) due to the very small industrial wastewater discharge compared to municipal wastewater discharge, but the contribution of PFAAs from I-WWTPs cannot be ignored.

  4. Phenolic compounds extracted by acidic aqueous ethanol from berries and leaves of different berry plants.

    PubMed

    Tian, Ye; Liimatainen, Jaana; Alanne, Aino-Liisa; Lindstedt, Anni; Liu, Pengzhan; Sinkkonen, Jari; Kallio, Heikki; Yang, Baoru

    2017-04-01

    Phenolic compounds of berries and leaves of thirteen various plant species were extracted with aqueous ethanol and analyzed with UPLC-DAD-ESI-MS, HPLC-DAD, and NMR. The total content of phenolics was consistently higher in leaves than in berries (25-7856 vs. 28-711mg/100g fresh weight). Sea buckthorn leaves were richest in phenolic compounds (7856mg/100g f.w.) with ellagitannins as the dominant compound class. Sea buckthorn berries contained mostly isorhamnetin glycosides, whereas quercetin glycosides were typically abundant in most samples investigated. Anthocyanins formed the dominating group of phenolics in most dark-colored berries but phenolic acid derivatives were equally abundant in saskatoon and chokeberry berries. Caffeoylquinic acids constituted 80% of the total phenolic content (1664mg/100g f.w.) in bilberry leaves. B-type procyanidins and caffeoylquinic acids were the major phenolic compounds in hawthorn and rowanberry, respectively. Use of leaves of some species with prunasin, tyramine and β-p-arbutin, may be limited in food applications.

  5. Seed Biofortification and Phytic Acid Reduction: A Conflict of Interest for the Plant?

    PubMed

    Sparvoli, Francesca; Cominelli, Eleonora

    2015-11-20

    Most of the phosphorus in seeds is accumulated in the form of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, InsP₆). This molecule is a strong chelator of cations important for nutrition, such as iron, zinc, magnesium, and calcium. For this reason, InsP₆ is considered an antinutritional factor. In recent years, efforts to biofortify seeds through the generation of low phytic acid (lpa) mutants have been noteworthy. Moreover, genes involved in the biosynthesis and accumulation of this molecule have been isolated and characterized in different species. Beyond its role in phosphorus storage, phytic acid is a very important signaling molecule involved in different regulatory processes during plant development and responses to different stimuli. Consequently, many lpa mutants show different negative pleitotropic effects. The strength of these pleiotropic effects depends on the specific mutated gene, possible functional redundancy, the nature of the mutation, and the spatio-temporal expression of the gene. Breeding programs or transgenic approaches aimed at development of new lpa mutants must take into consideration these different aspects in order to maximize the utility of these mutants.

  6. Ascorbic acid contents in transgenic potato plants overexpressing two dehydroascorbate reductase genes.

    PubMed

    Qin, Aiguo; Shi, Qinghua; Yu, Xianchang

    2011-03-01

    Ascorbic acid (AsA, vitamin C) is one of the most important nutritional quality factors in many horticultural crops and has many biological activities in the human body. Dehydroascorbate reductase (EC 1.8.5.1; DHAR) plays an important role in maintaining the normal level of ascorbic acid (AsA) by recycling oxidized ascorbic acid. To increase AsA content of potato, we isolated and characterized the cDNAs encoding two isoform DHARs localized in cytosol and chloroplast from potato, and developed two types of transgenic potato plants overexpressing cytosolic DHAR gene and chloroplastic DHAR, respectively. Incorporation of the transgene in the genome of potato was confirmed by PCR and real time RT-PCR. The overexpression of cytosolic DHAR significantly increased DHAR activities and AsA contents in potato leaves and tubers, whereas chloroplastic DHAR overexpression only increased DHAR activities and AsA contents in leaves, and did not change them in tubers. These results indicated that AsA content of potato can be elevated by enhancing recycling ascorbate via DHAR overexpression, moreover, cytosolic DHAR might play main important roles in improving the AsA contents of potato tubers.

  7. Seed Biofortification and Phytic Acid Reduction: A Conflict of Interest for the Plant?

    PubMed Central

    Sparvoli, Francesca; Cominelli, Eleonora

    2015-01-01

    Most of the phosphorus in seeds is accumulated in the form of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, InsP6). This molecule is a strong chelator of cations important for nutrition, such as iron, zinc, magnesium, and calcium. For this reason, InsP6 is considered an antinutritional factor. In recent years, efforts to biofortify seeds through the generation of low phytic acid (lpa) mutants have been noteworthy. Moreover, genes involved in the biosynthesis and accumulation of this molecule have been isolated and characterized in different species. Beyond its role in phosphorus storage, phytic acid is a very important signaling molecule involved in different regulatory processes during plant development and responses to different stimuli. Consequently, many lpa mutants show different negative pleitotropic effects. The strength of these pleiotropic effects depends on the specific mutated gene, possible functional redundancy, the nature of the mutation, and the spatio-temporal expression of the gene. Breeding programs or transgenic approaches aimed at development of new lpa mutants must take into consideration these different aspects in order to maximize the utility of these mutants. PMID:27135349

  8. Exposure assessment of boron in Bandırma boric acid production plant.

    PubMed

    Duydu, Yalçin; Başaran, Nurşen; Bolt, Hermann M

    2012-06-01

    Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. Experimentally, a NOAEL of 17.5mg B/kg-bw/day (corresponds to ∼2020 ng boron/g blood) has been identified for the (male) reproductive effects of boron in a multigenerational study of rats, and a NOAEL for the developmental effects in rats was identified at 9.6 mg B/kg-bw/day (corresponds to 1270 ng boron/g blood). These values are being taken as the basis of current EU safety assessments. The present study was conducted to assess the boron exposure under extreme exposure conditions in a boric acid production plant located in Bandırma, Turkey. The mean blood boron concentrations of low and high exposure groups were 72.94 ± 15.43 (48.46-99.91) and 223.89 ± 60.49 (152.82-454.02)ng/g respectively. The mean blood boron concentration of the high exposure group is still ≈ 6 times lower than the highest no effect level of boron in blood with regard to the developmental effects in rats and ≈ 9 times lower than the highest no effect level of boron in blood with regard to the reprotoxic effects in male rats. In this context, boric acid and sodium borates should not be considered as toxic to reproduction for humans in daily life.

  9. Evaluation of spectrophotometric and HPLC methods for shikimic acid determination in plants: models in glyphosate-resistant and -susceptible crops.

    PubMed

    Zelaya, Ian A; Anderson, Jennifer A H; Owen, Micheal D K; Landes, Reid D

    2011-03-23

    Endogenous shikimic acid determinations are routinely used to assess the efficacy of glyphosate in plants. Numerous analytical methods exist in the public domain for the detection of shikimic acid, yet