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Sample records for natural plant enzyme

  1. Natural plant enzyme inhibitors. Characterization of an unusual alpha-amylase/trypsin inhibitor from ragi (Eleusine coracana Geartn.).

    Science.gov (United States)

    Shivaraj, B; Pattabiraman, T N

    1981-01-01

    An inhibitor I-1, capable of acting on both alpha-amylase and trypsin, was purified to homogeneity from ragi (finger-millet) grains. The factor was found to be stable to heat treatment at 100 degrees C for 1 h in the presence of NaCl and also was stable over the wide pH range 1-10. Pepsin and Pronase treatment of inhibitor I-1 resulted in gradual loss of both the inhibitory activities. Formation of trypsin-inhibitor I-1 complex, amylase-inhibitor I-1 complex and trypsin-inhibitor I-1-amylase trimer complex was demonstrated by chromatography on a Bio-Gel P-200 column. This indicated that the inhibitor is 'double-headed' in nature. The inhibitor was retained on a trypsin-Sepharose 4B column at pH 7.0. Elution at acidic pH resulted in almost complete recovery of amylase-inhibitory and trypsin-inhibitory activities. alpha-Amylase was retained on a trypsin-Sepharose column to which inhibitor I-1 was bound, but not on trypsin-Sepharose alone. Modification of amino groups of the inhibitor with 2,4,6-trinitrobenzenesulphonic acid resulted in complete loss of amylase-inhibitory activity but only 40% loss in antitryptic activity. Modification of arginine residues by cyclohexane-1,2-dione led to 85% loss of antitryptic activity after 5 h, but no effect on amylase-inhibitory activity. The results show that a single bifunctional protein factor is responsible for both amylase-inhibitory and trypsin-inhibitory activities with two different reactive sites.

  2. Plant Products for Pharmacology: Application of Enzymes in Their Transformations

    Directory of Open Access Journals (Sweden)

    Marie Zarevúcka

    2008-12-01

    Full Text Available Different plant products have been subjected to detailed investigations due to their increasing importance for improving human health. Plants are sources of many groups of natural products, of which large number of new compounds has already displayed their high impact in human medicine. This review deals with the natural products which may be found dissolved in lipid phase (phytosterols, vitamins etc.. Often subsequent convenient transformation of natural products may further improve the pharmacological properties of new potential medicaments based on natural products. To respect basic principles of sustainable and green procedures, enzymes are often employed as efficient natural catalysts in such plant product transformations. Transformations of lipids and other natural products under the conditions of enzyme catalysis show increasing importance in environmentally safe and sustainable production of pharmacologically important compounds. In this review, attention is focused on lipases, efficient and convenient biocatalysts for the enantio- and regioselective formation / hydrolysis of ester bond in a wide variety of both natural and unnatural substrates, including plant products, eg. plant oils and other natural lipid phase compounds. The application of enzymes for preparation of acylglycerols and transformation of other natural products provides big advantage in comparison with employing of conventional chemical methods: Increased selectivity, higher product purity and quality, energy conservation, elimination of heavy metal catalysts, and sustainability of the employed processes, which are catalyzed by enzymes. Two general procedures are used in the transformation of lipid-like natural products: (a Hydrolysis/alcoholysis of triacylglycerols and (b esterification of glycerol. The reactions can be performed under conventional conditions or in supercritical fluids/ionic liquids. Enzyme-catalyzed reactions in supercritical fluids combine the

  3. Enzymes in bast fibrous plant processing.

    Science.gov (United States)

    Kozlowski, Ryszard; Batog, Jolanta; Konczewicz, Wanda; Mackiewicz-Talarczyk, Maria; Muzyczek, Malgorzata; Sedelnik, Natalia; Tanska, Bogumila

    2006-05-01

    The program COST Action 847 Textile Quality and Biotechnology (2000-2005) has given an excellent chance to review the possibilities of the research, aiming at development of the industrial application of enzymes for bast fibrous plant degumming and primary processing. The recent advancements in enzymatic processing of bast fibrous plants (flax, hemp, jute, ramie and alike plants) and related textiles are given. The performance of enzymes in degumming, modification of bast fibres, roving, yarn, related fabrics as well as enzymatic bonding of lignocellulosic composites is provided.

  4. Plant-polysaccharide-degrading enzymes from basidiomycetes

    NARCIS (Netherlands)

    Rytioja, Johanna; Hildén, Kristiina; Yuzon, Jennifer; Hatakka, Annele; de Vries, Ronald P; Mäkelä, Miia R; van den Brink, J.

    2014-01-01

    SUMMARY: Basidiomycete fungi subsist on various types of plant material in diverse environments, from living and dead trees and forest litter to crops and grasses and to decaying plant matter in soils. Due to the variation in their natural carbon sources, basidiomycetes have highly varied plant-poly

  5. Natural products for plant protection

    Directory of Open Access Journals (Sweden)

    Čeković Živorad

    2006-01-01

    Full Text Available The advantage applying natural products, such as a secondary metabolites, in plant protection is shortly presented. Acceptable solutions for the enhanced ecological criteria, which are requested by the users of pesticides and consumers of agricultural goods, could be the replacement of classical pesticides by natural products in plant protection. Some natural products are already in use as insecticides, herbicides and fungicides because new biotechnological processes, fermentation and biotransformations provide procedures for their industrial production. In addition to biotechnical processes natural compounds possessing pesticide activities are also prepared by chemical synthesis. An active secondary metabolite must first be isolated from natural sauces and then, based on biological toxicological and ecological studies, acceptable compounds are selected for laboratory and industrial chemical synthesis. Several compounds possessing insecticidal, herbicidal and fungicidal activities, which have been successfully applied for plan protection are presented.

  6. Efficient Enzyme-Free Biomimetic Sensors for Natural Phenol Detection.

    Science.gov (United States)

    Ferreira Garcia, Luane; Ribeiro Souza, Aparecido; Sanz Lobón, Germán; Dos Santos, Wallans Torres Pio; Alecrim, Morgana Fernandes; Fontes Santiago, Mariângela; de Sotomayor, Rafael Luque Álvarez; de Souza Gil, Eric

    2016-08-13

    The development of sensors and biosensors based on copper enzymes and/or copper oxides for phenol sensing is disclosed in this work. The electrochemical properties were studied by cyclic and differential pulse voltammetry using standard solutions of potassium ferrocyanide, phosphate/acetate buffers and representative natural phenols in a wide pH range (3.0 to 9.0). Among the natural phenols herein investigated, the highest sensitivity was observed for rutin, a powerful antioxidant widespread in functional foods and ubiquitous in the plant kingdom. The calibration curve for rutin performed at optimum pH (7.0) was linear in a broad concentration range, 1 to 120 µM (r = 0.99), showing detection limits of 0.4 µM. The optimized biomimetic sensor was also applied in total phenol determination in natural samples, exhibiting higher stability and sensitivity as well as distinct selectivity for antioxidant compounds.

  7. Marketing time predicts naturalization of horticultural plants.

    Science.gov (United States)

    Pemberton, Robert W; Liu, Hong

    2009-01-01

    Horticulture is an important source of naturalized plants, but our knowledge about naturalization frequencies and potential patterns of naturalization in horticultural plants is limited. We analyzed a unique set of data derived from the detailed sales catalogs (1887-1930) of the most important early Florida, USA, plant nursery (Royal Palm Nursery) to detect naturalization patterns of these horticultural plants in the state. Of the 1903 nonnative species sold by the nursery, 15% naturalized. The probability of plants becoming naturalized increases significantly with the number of years the plants were marketed. Plants that became invasive and naturalized were sold for an average of 19.6 and 14.8 years, respectively, compared to 6.8 years for non-naturalized plants, and the naturalization of plants sold for 30 years or more is 70%. Unexpectedly, plants that were sold earlier were less likely to naturalize than those sold later. The nursery's inexperience, which caused them to grow and market many plants unsuited to Florida during their early period, may account for this pattern. Plants with pantropical distributions and those native to both Africa and Asia were more likely to naturalize (42%), than were plants native to other smaller regions, suggesting that plants with large native ranges were more likely to naturalize. Naturalization percentages also differed according to plant life form, with the most naturalization occurring in aquatic herbs (36.8%) and vines (30.8%). Plants belonging to the families Araceae, Apocynaceae, Convolvulaceae, Moraceae, Oleaceae, and Verbenaceae had higher than expected naturalization. Information theoretic model selection indicated that the number of years a plant was sold, alone or together with the first year a plant was sold, was the strongest predictor of naturalization. Because continued importation and marketing of nonnative horticultural plants will lead to additional plant naturalization and invasion, a comprehensive approach

  8. Inhibitory Activities of Zygophyllum album: A Natural Weight-Lowering Plant on Key Enzymes in High-Fat Diet-Fed Rats

    Directory of Open Access Journals (Sweden)

    Kais Mnafgui

    2012-01-01

    Full Text Available Obesity is a serious health problem that increased risk for many complications, including diabetes and cardiovascular disease. The results showed EZA, which found rich in flavonoids and phenolic compounds, exhibited an inhibitory activity on pancreatic lipase in vitro with IC50 of 91.07 μg/mL. In vivo administration of this extract to HFD-rats lowered body weight and serum leptin level; and inhibited lipase activity of obese rats by 37% leading to notable decrease of T-Ch, TGs and LDL-c levels accompanied with an increase in HDL-c concentration in serum and liver of EZA treated HFD-rats. Moreover, the findings revealed that EZA helped to protect liver tissue from the appearance of fatty cysts. Interestingly, supplementation of EZA modulated key enzyme related to hypertension such as ACE by 36% in serum of HFD animals and improve some of serum electrolytes such as Na+, K+, Cl−, Ca2+ and Mg2+. Moreover, EZA significantly protected the liver-kidney function by reverted back near to normal the values of the liver-kidney dysfunction indices AST&ALT, ALP, CPK and GGT activities, decreased T-Bili, creat, urea and uric acid rates. In conclusion, these results showed a strong antihypelipidemic effect of EZA which can delay the occurrence of dislipidemia and hypertension.

  9. Inhibitory Activities of Zygophyllum album: A Natural Weight-Lowering Plant on Key Enzymes in High-Fat Diet-Fed Rats

    Science.gov (United States)

    Mnafgui, Kais; Hamden, Khaled; Ben Salah, Hichem; Kchaou, Mouna; Nasri, Mbarek; Slama, Sadok; Derbali, Fatma; Allouche, Noureddine; Elfeki, Abdelfattah

    2012-01-01

    Obesity is a serious health problem that increased risk for many complications, including diabetes and cardiovascular disease. The results showed EZA, which found rich in flavonoids and phenolic compounds, exhibited an inhibitory activity on pancreatic lipase in vitro with IC50 of 91.07 μg/mL. In vivo administration of this extract to HFD-rats lowered body weight and serum leptin level; and inhibited lipase activity of obese rats by 37% leading to notable decrease of T-Ch, TGs and LDL-c levels accompanied with an increase in HDL-c concentration in serum and liver of EZA treated HFD-rats. Moreover, the findings revealed that EZA helped to protect liver tissue from the appearance of fatty cysts. Interestingly, supplementation of EZA modulated key enzyme related to hypertension such as ACE by 36% in serum of HFD animals and improve some of serum electrolytes such as Na+, K+, Cl−, Ca2+ and Mg2+. Moreover, EZA significantly protected the liver-kidney function by reverted back near to normal the values of the liver-kidney dysfunction indices AST&ALT, ALP, CPK and GGT activities, decreased T-Bili, creat, urea and uric acid rates. In conclusion, these results showed a strong antihypelipidemic effect of EZA which can delay the occurrence of dislipidemia and hypertension. PMID:23258993

  10. Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Bergstrom Gary C

    2011-02-01

    Full Text Available Abstract Background The discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for the production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly cellulolytic and is a major industrial microbial source for commercial cellulases, xylanases and other cell wall degrading enzymes. However, enzyme-prospecting research continues to identify opportunities to enhance the activity of T. reesei enzyme preparations by supplementing with enzymatic diversity from other microbes. The goal of this study was to evaluate the enzymatic potential of a broad range of plant pathogenic and non-pathogenic fungi for their ability to degrade plant biomass and isolated polysaccharides. Results Large-scale screening identified a range of hydrolytic activities among 348 unique isolates representing 156 species of plant pathogenic and non-pathogenic fungi. Hierarchical clustering was used to identify groups of species with similar hydrolytic profiles. Among moderately and highly active species, plant pathogenic species were found to be more active than non-pathogens on six of eight substrates tested, with no significant difference seen on the other two substrates. Among the pathogenic fungi, greater hydrolysis was seen when they were tested on biomass and hemicellulose derived from their host plants (commelinoid monocot or dicot. Although T. reesei has a hydrolytic profile that is highly active on cellulose and pretreated biomass, it was less active than some natural isolates of fungi when tested on xylans and untreated biomass. Conclusions Several highly active isolates of plant pathogenic fungi were identified, particularly when tested on xylans and untreated biomass. There were statistically significant preferences for biomass type reflecting the monocot or dicot host preference of the

  11. The structural biology of enzymes involved in natural product glycosylation.

    Science.gov (United States)

    Singh, Shanteri; Phillips, George N; Thorson, Jon S

    2012-10-01

    The glycosylation of microbial natural products often dramatically influences the biological and/or pharmacological activities of the parental metabolite. Over the past decade, crystal structures of several enzymes involved in the biosynthesis and attachment of novel sugars found appended to natural products have emerged. In many cases, these studies have paved the way to a better understanding of the corresponding enzyme mechanism of action and have served as a starting point for engineering variant enzymes to facilitate to production of differentially-glycosylated natural products. This review specifically summarizes the structural studies of bacterial enzymes involved in biosynthesis of novel sugar nucleotides.

  12. Bioconversion potential of plant enzymes for the production of pharmaceuticals

    NARCIS (Netherlands)

    Pras, N; Woerdenbag, HJ; vanUden, W

    1995-01-01

    Plant enzymes are able to catalyze regio- and stereospecific reactions. Freely suspended and immobilized plant cells as well as enzyme preparations can therefore be applied for the production of pharmaceuticals by bioconversion, as such or in combination with chemical syntheses. This review paper

  13. Enzyme action in the regulation of plant hormone responses.

    Science.gov (United States)

    Westfall, Corey S; Muehler, Ashley M; Jez, Joseph M

    2013-07-05

    Plants synthesize a chemically diverse range of hormones that regulate growth, development, and responses to environmental stresses. The major classes of plant hormones are specialized metabolites with exquisitely tailored perception and signaling systems, but equally important are the enzymes that control the dose and exposure to the bioactive forms of these molecules. Here, we review new insights into the role of enzyme families, including the SABATH methyltransferases, the methylesterases, the GH3 acyl acid-amido synthetases, and the hormone peptidyl hydrolases, in controlling the biosynthesis and modifications of plant hormones and how these enzymes contribute to the network of chemical signals responsible for plant growth, development, and environmental adaptation.

  14. Genetic polymorphisms of the CYP1A1, GSTM1, and GSTT1 enzymes and their influence on cardiovascular risk and lipid profile in people who live near a natural gas plant.

    Science.gov (United States)

    Pašalić, Daria; Marinković, Natalija

    2017-03-01

    The aim of this cross-sectional study was to see whether genetic polymorphisms of the enzymes CYP1A1, GSTM1, and GSTT1 are associated with higher risk of coronary artery disease (CAD) and whether they affect lipid profile in 252 subjects living near a natural gas plant, who are likely to be exposed to polycyclic aromatic hydrocarbons (PAHs). Fasting serum concentrations of biochemical parameters were determined with standard methods. Genetic polymorphisms of CYP 1A1 rs4646903, rs1048943, rs4986883, and rs1799814 were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFPL), while GSTM1 and GSTT1 deletions were detected with multiplex PCR. Cardiovascular risk was assessed with Framingham risk score, and the subjects divided in two groups: >10% risk and ≤10% risk. The two groups did not differ in the genotype frequencies. MANCOVA analysis, which included lipid parameters, glucose, and BMI with sex, age, hypertension and smoking status as covariates, showed a significant difference between the GSTT1*0 and GSTT1*1 allele carriers (p=0.001). UNIANCOVA with same covariates showed that total cholesterol and triglyceride levels were significantly higher in GSTT1*1 allele carriers than in GSTT1*0 carriers (p<0.001 and p=0.006, respectively). Our findings suggest that CYP1A1, GSTM1, and GSTT1 polymorphisms are not associated with the higher risk of CAD, but that GSTT1 affects lipid profile.

  15. The nature of chemical innovation: new enzymes by evolution.

    Science.gov (United States)

    Arnold, Frances H

    2015-11-01

    I describe how we direct the evolution of non-natural enzyme activities, using chemical intuition and information on structure and mechanism to guide us to the most promising reaction/enzyme systems. With synthetic reagents to generate new reactive intermediates and just a few amino acid substitutions to tune the active site, a cytochrome P450 can catalyze a variety of carbene and nitrene transfer reactions. The cyclopropanation, N-H insertion, C-H amination, sulfimidation, and aziridination reactions now demonstrated are all well known in chemical catalysis but have no counterparts in nature. The new enzymes are fully genetically encoded, assemble and function inside of cells, and can be optimized for different substrates, activities, and selectivities. We are learning how to use nature's innovation mechanisms to marry some of the synthetic chemists' favorite transformations with the exquisite selectivity and tunability of enzymes.

  16. Plant Protein Inhibitors of Enzymes: Their Role in Animal Nutrition and Plant Defence.

    Science.gov (United States)

    Richardson, Michael

    1981-01-01

    Current information and research related to plant protein inhibitors of enzymes are reviewed, including potential uses of the inhibitors for medical treatment and for breeding plant varieties with greater resistance to insects. (DC)

  17. Plant tendrils: Nature's hygroscopic springs

    Science.gov (United States)

    Gerbode, Sharon; Puzey, Joshua; McCormick, Andrew; Mahadevan, L.

    2012-02-01

    Plant tendrils are specialized climbing organs that have fascinated biologists and physicists alike for centuries. Initially straight tendrils attach at the tip to an elevated rigid support and then winch the plant upward by coiling into a helical morphology characterized by two helices of opposite handedness connected by a helical perversion. In his renowned treatise on twining and tendril-bearing plants, Charles Darwin surmised that coiled tendrils serve as soft, springy attachments for the climbing plant. Yet, the true effect of the perverted helical shape of a coiled plant tendril has not been fully revealed. Using a combination of experiments on Cucurbitaceae tendrils, physical models constructed from strained rubber sheets, and numerical models of helical perversions, we have uncovered that tendril coiling occurs via anisotropic shrinkage of a strip of specialized cells in the interior of the tendril. Furthermore, variations in the mechanical behavior of tendrils as they become drier and ``woodier'' adds a new twist to the story of tendril coiling.

  18. Enzyme-assisted extraction of flavorings and colorants from plant materials.

    Science.gov (United States)

    Sowbhagya, H B; Chitra, V N

    2010-02-01

    From times immemorial, colorants, and flavorings have been used in foods. Color and flavor are the major attributes to the quality of a food product, affecting the appearance and acceptance of the product. As a consequence of the increased demand of natural flavoring and colorant from industries, there is a renewed interest in the research on the composition and recovery of natural food flavors and colors. Over the years, numerous procedures have been proposed for the isolation of aromatic compounds and colors from plant materials. Generally, the methods of extraction followed for aroma and pigment from plant materials are solvent extraction, hydro-distillation, steam distillation, and super critical carbon dioxide extraction. The application of enzymes in the extraction of oil from oil seeds like sunflower, corn, coconut, olives, avocado etc. are reported in literature. There is a great potential for this enzyme-based extraction technology with the selection of appropriate enzymes with optimized operating conditions. Various enzyme combinations are used to loosen the structural integrity of botanical material thereby enhancing the extraction of the desired flavor and color components. Recently enzymes have been used for the extraction of flavor and color from plant materials, as a pre-treatment of the raw material before subjecting the plant material to hydro distillation/solvent extraction. A deep knowledge of enzymes, their mode of action, conditions for optimum activity, and selection of the right type of enzymes are essential to use them effectively for extraction. Although the enzyme hydrolases such as lipases, proteases (chymotrypsin, subtilisin, thermolysin, and papain), esterases use water as a substrate for the reaction, they are also able to accept other nucleophiles such as alcohols, amines, thio-esters, and oximes. Advantages of enzyme-assisted extraction of flavor and color in some of the plant materials in comparison with conventional methods are

  19. Natural and Synthetic Macrocyclic Inhibitors of the Histone Deacetylase Enzymes

    DEFF Research Database (Denmark)

    Maolanon, Alex; Kristensen, Helle; Leman, Luke

    2017-01-01

    Inhibition of histone deacetylase (HDAC) enzymes has emerged as a target for development of cancer chemotherapy. Four compounds have gained approval for clinical use by the Food and Drug Administration (FDA) in the US, and several are currently in clinical trials. However, none of these compounds...... HDAC enzymes may hold an advantage over traditional hydroxamic acid-containing inhibitors, which rely on chelation to the conserved active site zinc ion. Here, we review the literature on macrocyclic HDAC inhibitors obtained from natural sources and structure-activity relationship studies inspired...

  20. Natural products – learning chemistry from plants

    NARCIS (Netherlands)

    Staniek, A.; Bouwmeester, H.J.; Fraser, P.D.; Kayser, O.; Martens, S.; Tissier, A.; Krol, van der A.R.; Wessjohann, L.; Warzecha, H.

    2014-01-01

    Plant natural products (PNPs) are unique in that they represent a vast array of different structural features, ranging from relatively simple molecules to very complex ones. Given the fact that many plant secondary metabolites exhibit profound biological activity, they are frequently used as

  1. Natural products – learning chemistry from plants

    NARCIS (Netherlands)

    Staniek, A.; Bouwmeester, H.J.; Fraser, P.D.; Kayser, O.; Martens, S.; Tissier, A.; Krol, van der A.R.; Wessjohann, L.; Warzecha, H.

    2014-01-01

    Plant natural products (PNPs) are unique in that they represent a vast array of different structural features, ranging from relatively simple molecules to very complex ones. Given the fact that many plant secondary metabolites exhibit profound biological activity, they are frequently used as fragran

  2. Carbohydrate-related enzymes of important Phytophthora plant pathogens

    NARCIS (Netherlands)

    Brouwer, Henk; Coutinho, Pedro M; Henrissat, Bernard; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    Carbohydrate-Active enZymes (CAZymes) form particularly interesting targets to study in plant pathogens. Despite the fact that many CAZymes are pathogenicity factors, oomycete CAZymes have received significantly less attention than effectors in the literature. Here we present an analysis of the CAZy

  3. Enzymes and Metabolites in Carbohydrate Metabolism of Desiccation Tolerant Plants

    Directory of Open Access Journals (Sweden)

    Qingwei Zhang

    2016-12-01

    Full Text Available Resurrection plants can tolerate extreme water loss. Substantial sugar accumulation is a phenomenon in resurrection plants during dehydration. Sugars have been identified as one important factor contributing to desiccation tolerance. Phylogenetic diversity of resurrection plants reflects the diversity of sugar metabolism in response to dehydration. Sugars, which accumulate during dehydration, have been shown to protect macromolecules and membranes and to scavenge reactive oxygen species. This review focuses on the performance of enzymes participating in sugar metabolism during dehydration stress. The relation between sugar metabolism and other biochemical activities is discussed and open questions as well as potential experimental approaches are proposed.

  4. Plant cell wall-degrading enzymes and their secretion in plant-pathogenic fungi.

    Science.gov (United States)

    Kubicek, Christian P; Starr, Trevor L; Glass, N Louise

    2014-01-01

    Approximately a tenth of all described fungal species can cause diseases in plants. A common feature of this process is the necessity to pass through the plant cell wall, an important barrier against pathogen attack. To this end, fungi possess a diverse array of secreted enzymes to depolymerize the main structural polysaccharide components of the plant cell wall, i.e., cellulose, hemicellulose, and pectin. Recent advances in genomic and systems-level studies have begun to unravel this diversity and have pinpointed cell wall-degrading enzyme (CWDE) families that are specifically present or enhanced in plant-pathogenic fungi. In this review, we discuss differences between the CWDE arsenal of plant-pathogenic and non-plant-pathogenic fungi, highlight the importance of individual enzyme families for pathogenesis, illustrate the secretory pathway that transports CWDEs out of the fungal cell, and report the transcriptional regulation of expression of CWDE genes in both saprophytic and phytopathogenic fungi.

  5. Dual-enzyme natural motors incorporating decontamination and propulsion capabilities

    OpenAIRE

    Sattayasamitsathit, S; Kaufmann, K; Galarnyk, M; Vazquez-Duhalt, R.; Wang, J

    2014-01-01

    Self-propelled dual-function biocatalytic motors, consisting of unmodified natural tissue and capable of in-motion bioremediation, are described. These enzyme-rich tissue motors rely on the catalase and peroxidase activities of their Raphanus sativus radish body for their propulsion and remediation actions, respectively. The continuous movement of the biocatalytic tissue motors through the contaminated sample facilitates the dynamic removal of phenolic pollutants. Hydrogen peroxide plays a du...

  6. A Review on Venom Enzymes Neutralizing Ability of Secondary Metabolites from Medicinal Plants

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    Pushpendra Singh

    2017-09-01

    Full Text Available Objectives: Medicinal plants are vital sources of bioactive compounds that are useful for the treatment of patients with snake bites or are indirectly applicable for boosting the effects of conventional serum therapy. These plants are being used traditionally by local healers and tribes for the treatment of patients with snake bites and therefore can be used as an alternative against snake envenomation. Scientifically, using the secondary metabolites of plants to neutralize venom enzymes has an extra benefit of being based on traditional knowledge; also, the use of such metabolites for the treatment of patients with snake bites is cheaper and the treatment can be started sooner. Methods: All the available information on various secondary metabolites exhibiting venom neutralizing ability were collected via electronic search (using Google books, Pubmed, SciFinder, Scirus, Google Scholar, and Web of Science and articles of peer-reviewed journals. Results: Recent interest in different plant has focused on isolating and identifying of different phytoconstituents that exhibit Phospholipase A2 activity and other venom enzyme neutralizing ability. In this support convincing evidence in experimental animal models are available. Conclusion: Secondary metabolites are naturally present, have no side effect, are stable for a long time, can be easily stored, and can neutralize a wide range of snake enzymes, such as phospholipase A2, hyaluronidase, protease, L-amino acid oxidase, 5’nucleotidase, etc. The current review presents a compilation of important plant secondary metabolites that are effective against snake venom due to enzyme neutralization.

  7. SCADA Architecture for Natural Gas plant

    OpenAIRE

    Turc Traian; Grif Horaţiu

    2009-01-01

    The paper describes the Natural Gas Plant SCADA architecture. The main purpose of SCADA system is remote monitoring and controlling of any industrial plant. The SCADA hardware architecture is based on multi-dropping system allowing connecting a large number of different fiels devices. The SCADA Server gathers data from gas plant and stores data to a MtSQL database. The SCADA server is connected to other SCADA client application offers a intuitive and user-friendly HMI. The main benefit of us...

  8. Carbohydrate-related enzymes of important Phytophthora plant pathogens.

    Science.gov (United States)

    Brouwer, Henk; Coutinho, Pedro M; Henrissat, Bernard; de Vries, Ronald P

    2014-11-01

    Carbohydrate-Active enZymes (CAZymes) form particularly interesting targets to study in plant pathogens. Despite the fact that many CAZymes are pathogenicity factors, oomycete CAZymes have received significantly less attention than effectors in the literature. Here we present an analysis of the CAZymes present in the Phytophthora infestans, Ph. ramorum, Ph. sojae and Pythium ultimum genomes compared to growth of these species on a range of different carbon sources. Growth on these carbon sources indicates that the size of enzyme families involved in degradation of cell-wall related substrates like cellulose, xylan and pectin is not always a good predictor of growth on these substrates. While a capacity to degrade xylan and cellulose exists the products are not fully saccharified and used as a carbon source. The Phytophthora genomes encode larger CAZyme sets when compared to Py. ultimum, and encode putative cutinases, GH12 xyloglucanases and GH10 xylanases that are missing in the Py. ultimum genome. Phytophthora spp. also encode a larger number of enzyme families and genes involved in pectin degradation. No loss or gain of complete enzyme families was found between the Phytophthora genomes, but there are some marked differences in the size of some enzyme families.

  9. A saponin-detoxifying enzyme mediates suppression of plant defences

    Science.gov (United States)

    Bouarab, K.; Melton, R.; Peart, J.; Baulcombe, D.; Osbourn, A.

    2002-08-01

    Plant disease resistance can be conferred by constitutive features such as structural barriers or preformed antimicrobial secondary metabolites. Additional defence mechanisms are activated in response to pathogen attack and include localized cell death (the hypersensitive response). Pathogens use different strategies to counter constitutive and induced plant defences, including degradation of preformed antimicrobial compounds and the production of molecules that suppress induced plant defences. Here we present evidence for a two-component process in which a fungal pathogen subverts the preformed antimicrobial compounds of its host and uses them to interfere with induced defence responses. Antimicrobial saponins are first hydrolysed by a fungal saponin-detoxifying enzyme. The degradation product of this hydrolysis then suppresses induced defence responses by interfering with fundamental signal transduction processes leading to disease resistance.

  10. Biosynthesis of Carotenoids in Plants: Enzymes and Color.

    Science.gov (United States)

    Rosas-Saavedra, Carolina; Stange, Claudia

    2016-01-01

    Carotenoids are the most important biocolor isoprenoids responsible for yellow, orange and red colors found in nature. In plants, they are synthesized in plastids of photosynthetic and sink organs and are essential molecules for photosynthesis, photo-oxidative damage protection and phytohormone synthesis. Carotenoids also play important roles in human health and nutrition acting as vitamin A precursors and antioxidants. Biochemical and biophysical approaches in different plants models have provided significant advances in understanding the structural and functional roles of carotenoids in plants as well as the key points of regulation in their biosynthesis. To date, different plant models have been used to characterize the key genes and their regulation, which has increased the knowledge of the carotenoid metabolic pathway in plants. In this chapter a description of each step in the carotenoid synthesis pathway is presented and discussed.

  11. SCADA Architecture for Natural Gas plant

    Directory of Open Access Journals (Sweden)

    Turc Traian

    2009-12-01

    Full Text Available The paper describes the Natural Gas Plant SCADA architecture. The main purpose of SCADA system is remote monitoring and controlling of any industrial plant. The SCADA hardware architecture is based on multi-dropping system allowing connecting a large number of different fiels devices. The SCADA Server gathers data from gas plant and stores data to a MtSQL database. The SCADA server is connected to other SCADA client application offers a intuitive and user-friendly HMI. The main benefit of using SCADA is real time displaying of gas plant state. The main contriobution of the authors consists in designing SCADA architecture based on multi-dropping system and Human Machine Interface.

  12. Transglutaminases: widespread cross-linking enzymes in plants.

    Science.gov (United States)

    Serafini-Fracassini, Donatella; Del Duca, Stefano

    2008-08-01

    Transglutaminases have been studied in plants since 1987 in investigations aimed at interpreting some of the molecular mechanisms by which polyamines affect growth and differentiation. Transglutaminases are a widely distributed enzyme family catalysing a myriad of biological reactions in animals. In plants, the post-translational modification of proteins by polyamines forming inter- or intra-molecular cross-links has been the main transglutaminase reaction studied. The few plant transglutaminases sequenced so far have little sequence homology with the best-known animal enzymes, except for the catalytic triad; however, they share a possible structural homology. Proofs of their catalytic activity are: (a) their ability to produce glutamyl-polyamine derivatives; (b) their recognition by animal transglutaminase antibodies; and (c) biochemical features such as calcium-dependency, etc. However, many of their fundamental biochemical and physiological properties still remain elusive. It has been detected in algae and in angiosperms in different organs and sub-cellular compartments, chloroplasts being the best-studied organelles. Possible roles concern the structural modification of specific protein substrates. In chloroplasts, transglutaminases appear to stabilize the photosynthetic complexes and Rubisco, being regulated by light and other factors, and possibly exerting a positive effect on photosynthesis and photo-protection. In the cytosol, they modify cytoskeletal proteins. Preliminary reports suggest an involvement in the cell wall construction/organization. Other roles appear to be related to fertilization, abiotic and biotic stresses, senescence and programmed cell death, including the hypersensitive reaction. The widespread occurrence of transglutaminases activity in all organs and cell compartments studied suggests a relevance for their still incompletely defined physiological roles. At present, it is not possible to classify this enzyme family in plants owing to

  13. Vacuolar processing enzyme in plant programmed cell death

    Directory of Open Access Journals (Sweden)

    Noriyuki eHatsugai

    2015-04-01

    Full Text Available Vacuolar processing enzyme (VPE is a cysteine proteinase originally identified as the proteinase responsible for the maturation and activation of vacuolar proteins in plants, and it is known to be an orthologue of animal asparaginyl endopeptidase (AEP/VPE/legumain. VPE has been shown to exhibit enzymatic properties similar to that of caspase 1, which is a cysteine protease that mediates the programmed cell death (PCD pathway in animals. Although there is limited sequence identity between VPE and caspase 1, their predicted three-dimensional structures revealed that the essential amino-acid residues for these enzymes form similar pockets for the substrate peptide YVAD. In contrast to the cytosolic localization of caspases, VPE is localized in vacuoles. VPE provokes vacuolar rupture, initiating the proteolytic cascade leading to PCD in the plant immune response. It has become apparent that the VPE-dependent PCD pathway is involved not only in the immune response, but also in the responses to a variety of stress inducers and in the development of various tissues. This review summarizes the current knowledge on the contribution of VPE to plant PCD and its role in vacuole-mediated cell death, and it also compares VPE with the animal cell death executor caspase 1.

  14. Plant biochemistry: a naturally decaffeinated arabica coffee.

    Science.gov (United States)

    Silvarolla, Maria B; Mazzafera, Paulo; Fazuoli, Luiz C

    2004-06-24

    The adverse side effects of caffeine have increased the market for decaffeinated coffee to about 10% of coffee consumption worldwide (http://www.ncausa.org), despite the loss of key flavour compounds in the industrial decaffeinating process. We have discovered a naturally decaffeinated Coffea arabica plant from Ethiopia, a species normally recognized for the high quality of its beans. It should be possible to transfer this trait to commercial varieties of arabica coffee plants by intraspecific hybridization--a process likely to be simpler than an interspecific hybridization strategy, which could require more than 30 years of breeding to fix the decaffeinated trait and would probably result in an inferior cup of coffee.

  15. The nature of selection during plant domestication.

    Science.gov (United States)

    Purugganan, Michael D; Fuller, Dorian Q

    2009-02-12

    Plant domestication is an outstanding example of plant-animal co-evolution and is a far richer model for studying evolution than is generally appreciated. There have been numerous studies to identify genes associated with domestication, and archaeological work has provided a clear understanding of the dynamics of human cultivation practices during the Neolithic period. Together, these have provided a better understanding of the selective pressures that accompany crop domestication, and they demonstrate that a synthesis from the twin vantage points of genetics and archaeology can expand our understanding of the nature of evolutionary selection that accompanies domestication.

  16. BIOCONVERSION OF NATURALLY-OCCURRING PRECURSORS AND RELATED SYNTHETIC COMPOUNDS USING PLANT-CELL CULTURES

    NARCIS (Netherlands)

    PRAS, N

    1992-01-01

    The nearly unlimited enzymatic potential of cultured plant cells can basically be employed for bioconversion purposes. Plant enzymes are able to catalyze regio- and stereospecific reactions and can therefore be applied to the production of compounds of pharmaceutical interest. Naturally occurring as

  17. The Study of Natural Isolates of Fusarium spp. Micromycetes – Ligninolytic Enzymes Producers

    Directory of Open Access Journals (Sweden)

    I.V. Darmov

    2017-03-01

    Full Text Available It is known that many basidiomycetes, white rot agents of wood in particular, produce ligninolytic complex enzymes, the most important of which are laccase, manganese peroxidase, and lignin peroxidase. Using these basidiomycete enzymes, promising methods have been developed for disposal of logging and plant farming wastes, paper stock delignification, cloth bio-bleaching, and production of wooden fibreboards; however, these techniques are not commonly applied on an industrial scale. It should be noted that wood lignin can be also destructed by various micromycetes, such as Fusarium, Trichoderma, Aspergillus, Penicillium, etc. Nevertheless, the range of ligninolytic complex enzymes produced by them, as well as the level of their activity and localization in a cell, have been studied insufficiently. Thus, it is not possible to fully appreciate the ligninolytic potential of micromycetes. The purpose of this research is to evaluate the ability of natural isolates of Fusarium spp. to produce laccase, manganese peroxidase, and lignin peroxidase. Furthermore, the level of activity of these enzymes in the culture liquid and cell mass of producers has been determined. The following natural isolates of micromycetes have been isolated and identified from natural envi-ronments of the Kirov region: F. culmorum, strain 3, F. sporotrichioides, strain 12, and F. solani, strain 52, all capable of degradation of wood lignin and carrying simultaneously genetic determinants of all the three major ligninolytic enzymes – laccase, manganese peroxidase, and lignin peroxidase. We have studied the dynamics of the activity of these enzymes in the culture liquid supernatants at deep micromycete cultivation. The enzyme activity has been determined by the spectrophotometric method. In terms of laccase and manganese peroxidase production, two micromycete strains – F. culmorum 3 and F. sporotrichioides 12 – have been almost as good as the basidiomycete T. versicolor

  18. Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

    Science.gov (United States)

    Discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly c...

  19. NATURAL PLANT TOXICANT – CYANOGENIC GLYCOSIDE AMYGDALIN: CHARACTERISTIC, METABOLISM AND THE EFFECT ON ANIMAL REPRODUCTION

    OpenAIRE

    Eduard Kolesár; Marek Halenár; Adriana Kolesárová; Peter Massányi

    2015-01-01

    The amount of cyanogenic glycosides, as natural plant toxicants, in plants varies with plant species and environmental effects. Cyanogenic glycoside as an amygdalin was detected in apricot kernels, bitter almonds and peach, plum, pear and apple seeds. Amygdalin itself is non-toxic, but its HCN production decomposed by some enzymes is toxic substance. Target of this review was to describe the characteristic, metabolism and possible effects of amygdalin on reproductive processes. Previous studi...

  20. Geographic and molecular variation in a natural plant transgene.

    Science.gov (United States)

    Vallenback, Pernilla; Bengtsson, Bengt O; Ghatnekar, Lena

    2010-03-01

    A PCR based survey of Festuca ovina plants from populations around the southern part of the Baltic Sea demonstrates both geographic and molecular variation in the enzyme gene PgiC2, horizontally transferred from a Poa-species. Our results show that PgiC2-a natural functional nuclear transgene-is not a local ephemeral phenomenon but is present in a very large number of individuals. We find also that its frequency is geographically variable and that it appears in more than one molecular form. The chloroplast variation in the region does not indicate any distinct subdivision due to different colonization routes after the last glaciation. Our data illustrate the geographic and molecular variation that may occur in natural populations with a polymorphic, unfixed transgene affected by diverse kinds of mutational and evolutionary processes.

  1. Sensitive Plants - Center for Natural Lands Management [ds458

    Data.gov (United States)

    California Department of Resources — This dataset represents sensitive plant data collected on Center for Natural Lands Management (CNLM) dedicated nature preserves in San Diego County, California. Data...

  2. Fungal Enzymes and Yeasts for Conversion of Plant Biomass to Bioenergy and High-Value Products.

    Science.gov (United States)

    Lange, Lene

    2017-01-01

    Fungi and fungal enzymes play important roles in the new bioeconomy. Enzymes from filamentous fungi can unlock the potential of recalcitrant lignocellulose structures of plant cell walls as a new resource, and fungi such as yeast can produce bioethanol from the sugars released after enzyme treatment. Such processes reflect inherent characteristics of the fungal way of life, namely, that fungi as heterotrophic organisms must break down complex carbon structures of organic materials to satisfy their need for carbon and nitrogen for growth and reproduction. This chapter describes major steps in the conversion of plant biomass to value-added products. These products provide a basis for substituting fossil-derived fuels, chemicals, and materials, as well as unlocking the biomass potential of the agricultural harvest to yield more food and feed. This article focuses on the mycological basis for the fungal contribution to biorefinery processes, which are instrumental for improved resource efficiency and central to the new bioeconomy. Which types of processes, inherent to fungal physiology and activities in nature, are exploited in the new industrial processes? Which families of the fungal kingdom and which types of fungal habitats and ecological specializations are hot spots for fungal biomass conversion? How can the best fungal enzymes be found and optimized for industrial use? How can they be produced most efficiently-in fungal expression hosts? How have industrial biotechnology and biomass conversion research contributed to mycology and environmental research? Future perspectives and approaches are listed, highlighting the importance of fungi in development of the bioeconomy.

  3. Bringing functions together with fusion enzymes--from nature's inventions to biotechnological applications.

    Science.gov (United States)

    Elleuche, Skander

    2015-02-01

    It is a mammoth task to develop a modular protein toolbox enabling the production of posttranslational organized multifunctional enzymes that catalyze reactions in complex pathways. However, nature has always guided scientists to mimic evolutionary inventions in the laboratory and, nowadays, versatile methods have been established to experimentally connect enzymatic activities with multiple advantages. Among the oldest known natural examples is the linkage of two or more juxtaposed proteins catalyzing consecutive, non-consecutive, or opposing reactions by a native peptide bond. There are multiple reasons for the artificial construction of such fusion enzymes including improved catalytic activities, enabled substrate channelling by proximity of biocatalysts, higher stabilities, and cheaper production processes. To produce fused proteins, it is either possible to genetically fuse coding open reading frames or to connect proteins in a posttranslational process. Molecular biology techniques that have been established for the production of end-to-end or insertional fusions include overlap extension polymerase chain reaction, cloning, and recombination approaches. Depending on their flexibility and applicability, these methods offer various advantages to produce fusion genes in high throughput, different orientations, and including linker sequences to maximize the flexibility and performance of fusion partners. In this review, practical techniques to fuse genes are highlighted, enzymatic parameters to choose adequate enzymes for fusion approaches are summarized, and examples with biotechnological relevance are presented including a focus on plant biomass-degrading glycosyl hydrolases.

  4. Plants as natural antioxidants for meat products

    Science.gov (United States)

    Tomović, V.; Jokanović, M.; Šojić, B.; Škaljac, S.; Ivić, M.

    2017-09-01

    The meat industry is demanding antioxidants from natural sources to replace synthetic antioxidants because of the negative health consequences or beliefs regarding some synthetic ones. Plants materials provide good alternatives. Spices and herbs, generally used for their flavouring characteristics, can be added to meat products in various forms: whole, ground, or as isolates from their extracts. These natural antioxidants contain some active compounds, which exert antioxidative potential in meat products. This antioxidant activity is most often due to phenolic acids, phenolic diterpenes, flavonoids and volatile oils. Each of these compounds often has strong H-donating activity, thus making them extremely effective antioxidants; some compounds can chelate metals and donate H to oxygen radicals, thus slowing oxidation via two mechanisms. Numerous studies have demonstrated the efficacy of natural antioxidants when used in meat products. Based on this literature review, it can be concluded that natural antioxidants are added to fresh and processed meat and meat products to delay, retard, or prevent lipid oxidation, retard development of off-flavours (rancidity), improve colour stability, improve microbiological quality and extend shelf-life, without any damage to the sensory or nutritional properties.

  5. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

    Science.gov (United States)

    Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

    2016-06-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2‧,3‧,4‧,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2‧,3‧,4‧-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme.

  6. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Directory of Open Access Journals (Sweden)

    Jun-Fei Gu

    2013-12-01

    Full Text Available Maize-specific pyruvate orthophosphate dikinase (PPDK was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase (PCK. The wild-type (WT cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments, well-watered (WW, moderate drought (MD and severe drought (SD, were imposed from 9 d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities, biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines (PPDK and PCK were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by 45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%, 20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments, respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase (PEPC and carbonic anhydrase (CA in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4 photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to drought-tolerance breeding via overexpression of C4 enzymes in rice.

  7. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Institute of Scientific and Technical Information of China (English)

    Jun-Fei; Gu; Ming; Qiu; Jian-Chang; Yang

    2013-01-01

    Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.

  8. Tailoring enzyme-rich environmental DNA clones: a source of enzymes for generating libraries of unnatural natural products.

    Science.gov (United States)

    Banik, Jacob J; Craig, Jeffrey W; Calle, Paula Y; Brady, Sean F

    2010-11-10

    A detailed bioinformatics analysis of six glycopeptide biosynthetic gene clusters isolated from soil environmental DNA (eDNA) megalibraries indicates that a subset of these gene clusters contains collections of tailoring enzymes that are predicted to result in the production of new glycopeptide congeners. In particular, sulfotransferases appear in eDNA-derived gene clusters at a much higher frequency than would be predicted from the characterization of glycopeptides from cultured Actinomycetes . Enzymes found on tailoring-enzyme-rich eDNA clones associated with these six gene clusters were used to produce a series of new sulfated glycopeptide derivatives in both in vitro and in vivo derivatization studies. The derivatization of known natural products with eDNA-derived tailoring enzymes is likely to be a broadly applicable strategy for generating libraries of new natural product variants.

  9. The Isolation and Characterization of Glucoamylase Enzyme of an Aspergillus niger Natural Isolate

    OpenAIRE

    CORAL, Gökhan

    2014-01-01

    An extracellular glucoamylase enzyme was isolated from Aspergillus niger Z10 natural isolate in a liquid Czapek Dox medium which contained soluble starch (2%) as the sole carbon source. The molecular weight of the enzyme was found to be about 100.000 Daltons through Starch-SDS Polyacrylamide Gel Electrophoresis. The optimal pH range of the enzyme was found to be 4.5-5.5 and it was determined that the thermal stability of this enzyme is quite high.

  10. The Isolation and Characterization of Glucoamylase Enzyme of an Aspergillus niger Natural Isolate

    OpenAIRE

    CORAL, Gökhan

    2000-01-01

    An extracellular glucoamylase enzyme was isolated from Aspergillus niger Z10 natural isolate in a liquid Czapek Dox medium which contained soluble starch (2%) as the sole carbon source. The molecular weight of the enzyme was found to be about 100.000 Daltons through Starch-SDS Polyacrylamide Gel Electrophoresis. The optimal pH range of the enzyme was found to be 4.5-5.5 and it was determined that the thermal stability of this enzyme is quite high.

  11. Expanding the enzyme universe: accessing non-natural reactions by mechanism-guided directed evolution.

    Science.gov (United States)

    Renata, Hans; Wang, Z Jane; Arnold, Frances H

    2015-03-09

    High selectivity and exquisite control over the outcome of reactions entice chemists to use biocatalysts in organic synthesis. However, many useful reactions are not accessible because they are not in nature's known repertoire. In this Review, we outline an evolutionary approach to engineering enzymes to catalyze reactions not found in nature. We begin with examples of how nature has discovered new catalytic functions and how such evolutionary progression has been recapitulated in the laboratory starting from extant enzymes. We then examine non-native enzyme activities that have been exploited for chemical synthesis, with an emphasis on reactions that do not have natural counterparts. Non-natural activities can be improved by directed evolution, thus mimicking the process used by nature to create new catalysts. Finally, we describe the discovery of non-native catalytic functions that may provide future opportunities for the expansion of the enzyme universe. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Structure of a Berberine Bridge Enzyme-Like Enzyme with an Active Site Specific to the Plant Family Brassicaceae

    DEFF Research Database (Denmark)

    Daniel, Bastian; Wallner, Silvia; Steiner, Barbara;

    2016-01-01

    Berberine bridge enzyme-like (BBE-like) proteins form a multigene family (pfam 08031), which is present in plants, fungi and bacteria. They adopt the vanillyl alcohol-oxidase fold and predominantly show bi-covalent tethering of the FAD cofactor to a cysteine and histidine residue, respectively...

  13. Enzyme

    Science.gov (United States)

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  14. Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

    Directory of Open Access Journals (Sweden)

    Wei Hui

    2012-04-01

    Full Text Available Abstract Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera wood-chips and mown lawn grass clippings (85:15 in dry-weight and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

  15. Tracking Dynamics of Plant Biomass Composting by Changes in Substrate Structure, Microbial Community, and Enzyme Activity

    Energy Technology Data Exchange (ETDEWEB)

    Wei, H.; Tucker, M. P.; Baker, J. O.; Harris, M.; Luo, Y. H.; Xu, Q.; Himmel, M. E.; Ding, S. Y.

    2012-04-01

    Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera) wood-chips and mown lawn grass clippings (85:15 in dry-weight) and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP) and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

  16. Plant lipid environment and membrane enzymes: the case of the plasma membrane H+-ATPase.

    Science.gov (United States)

    Morales-Cedillo, Francisco; González-Solís, Ariadna; Gutiérrez-Angoa, Lizbeth; Cano-Ramírez, Dora Luz; Gavilanes-Ruiz, Marina

    2015-04-01

    Several lipid classes constitute the universal matrix of the biological membranes. With their amphipathic nature, lipids not only build the continuous barrier that confers identity to every cell and organelle, but they are also active actors that modulate the activity of the proteins immersed in the lipid bilayer. The plasma membrane H(+)-ATPase, an enzyme from plant cells, is an excellent example of a transmembrane protein whose activity is influenced by the hydrophilic compartments at both sides of the membrane and by the hydrophobic domains of the lipid bilayer. As a result, an extensive documentation of the effect of numerous amphiphiles in the enzyme activity can be found. Detergents, membrane glycerolipids, and sterols can produce activation or inhibition of the enzyme activity. In some cases, these effects are associated with the lipids of the membrane bulk, but in others, a direct interaction of the lipid with the protein is involved. This review gives an account of reports related to the action of the membrane lipids on the H(+)-ATPase activity.

  17. Inhibition of human P450 enzymes by natural extracts used in traditional medicine.

    Science.gov (United States)

    Rodeiro, Idania; Donato, María T; Jimenez, Nuria; Garrido, Gabino; Molina-Torres, Jorge; Menendez, Roberto; Castell, José V; Gómez-Lechón, María J

    2009-02-01

    Different medicinal plants are widely used in Cuba and Mexico to treat several disorders. This paper reports in vitro inhibitory effects on the P450 system of herbal products commonly used by people in Cuba and Mexico in traditional medicine for decades. Experiments were conducted in human liver microsomes. The catalytic activities of CYP1A1/2, 2D6, and 3A4 were measured using specific probe substrates. The Heliopsis longipes extract exhibited a concentration-dependent inhibition of the three enzymes, and similar effects were produced by affinin (an alkamide isolated from the H. longipes extract) and two catalytically reduced alkamides. Mangifera indica L. and Thalassia testudinum extracts, two natural polyphenol-rich extracts, diminished CYP1A1/2 and 3A4 activities, but not the CYP2D6 activity. These results suggest that these herbs inhibit the major human P450 enzymes involved in drug metabolism and could induce potential herbal-drug interactions.

  18. Caterpillar-induced plant volatiles attract conspecific adults in nature

    Science.gov (United States)

    Plants release volatiles in response to caterpillar feeding that attracts natural enemies of the herbivores, a tri-trophic interaction which has been considered an indirect plant defence against herbivores. The caterpillar-induced plant volatiles have been reported to repel or attract conspecific ad...

  19. Bioprospecting plants for natural antioxidants: An overview

    Directory of Open Access Journals (Sweden)

    Huma Qureshi

    2016-10-01

    Full Text Available Reactive oxygen species damage cellular proteins and lipids or form DNA adducts when present in high concentration that promotes carcinogenic activities. Plants have been the primary therapy for such ailments since ancient times. This paper reviews some medicinal plants having antioxidant activities useful for healing cancer, cardiovascular diseases and neuro-protection. A brief overview of the use of medicinal plants and their main constituents effective against reactive oxygen species-based diseases are presented. This overview will attract the interest of investigators aiming at the design of novel therapeutic approaches for the treatment of various reactive oxygen species-based conditions.

  20. In-vitro engineering of novel bioactivity in the natural enzymes

    Directory of Open Access Journals (Sweden)

    Vishvanath Tiwari

    2016-10-01

    Full Text Available Enzymes catalyze various biochemical functions with high efficiency and specificity. In-vitro design of the enzyme leads to novel bioactivity in this natural biomolecule that give answers of some vital questions like crucial residues in binding with substrate, molecular evolution, cofactor specificity etc. Enzyme engineering technology involves directed evolution, rational designing, semi-rational designing and structure-based designing using chemical modifications. Similarly, combined computational and in-vitro evolution approaches together help in artificial designing of novel bioactivity in the natural enzyme. DNA shuffling, error prone PCR and staggered extension process are used to artificially redesign active site of enzyme, which can alter its efficiency and specificity. Modifications of the enzyme can lead to the discovery of new path of molecular evolution, designing of efficient enzymes, locating active sites and crucial residues, shift in substrate and cofactor specificity. The methods and thermodynamics of in-vitro designing of the enzyme are also discussed. Similarly, engineered thermophilic and psychrophilic enzymes attain substrate specificity and activity of mesophilic enzymes that may also be beneficial for industry and therapeutics.

  1. In-vitro engineering of novel bioactivity in the natural enzymes

    Science.gov (United States)

    Tiwari, Vishvanath

    2016-10-01

    Enzymes catalyze various biochemical functions with high efficiency and specificity. In-vitro design of the enzyme leads to novel bioactivity in this natural biomolecule that give answers of some vital questions like crucial residues in binding with substrate, molecular evolution, cofactor specificity etc. Enzyme engineering technology involves directed evolution, rational designing, semi-rational designing and structure-based designing using chemical modifications. Similarly, combined computational and in-vitro evolution approaches together help in artificial designing of novel bioactivity in the natural enzyme. DNA shuffling, error prone PCR and staggered extension process are used to artificially redesign active site of enzyme, which can alter its efficiency and specificity. Modifications of the enzyme can lead to the discovery of new path of molecular evolution, designing of efficient enzymes, locating active sites and crucial residues, shift in substrate and cofactor specificity. The methods and thermodynamics of in-vitro designing of the enzyme are also discussed. Similarly, engineered thermophilic and psychrophilic enzymes attain substrate specificity and activity of mesophilic enzymes that may also be beneficial for industry and therapeutics.

  2. Enhanced transformation of TNT by Arabidopsis plants expressing an old yellow enzyme.

    Science.gov (United States)

    Zhu, Bo; Peng, Ri-He; Fu, Xiao-Yan; Jin, Xiao-Fen; Zhao, Wei; Xu, Jing; Han, Hong-Juan; Gao, Jian-Jie; Xu, Zhi-Sheng; Bian, Lin; Yao, Quan-Hong

    2012-01-01

    2,4,6-Trinitrotoluene (TNT) is released in nature from manufacturing or demilitarization facilities, as well as after the firing or detonation of munitions or leakage from explosive remnants of war. Environmental contamination by TNT is associated with human health risks, necessitating the development of cost-effective remediation techniques. The lack of affordable and effective cleanup technologies for explosives contamination requires the development of better processes. In this study, we present a system for TNT phytoremediation by overexpressing the old yellow enzyme (OYE3) gene from Saccharomyces cerevisiae. The resulting transgenic Arabidopsis plants demonstrated significantly enhanced TNT tolerances and a strikingly higher capacity to remove TNT from their media. The current work indicates that S. cerevisiae OYE3 overexpression in Arabidopsis is an efficient method for the phytoremoval and degradation of TNT. Our findings have the potential to provide a suitable remediation strategy for sites contaminated by TNT.

  3. Enhanced transformation of TNT by Arabidopsis plants expressing an old yellow enzyme.

    Directory of Open Access Journals (Sweden)

    Bo Zhu

    Full Text Available 2,4,6-Trinitrotoluene (TNT is released in nature from manufacturing or demilitarization facilities, as well as after the firing or detonation of munitions or leakage from explosive remnants of war. Environmental contamination by TNT is associated with human health risks, necessitating the development of cost-effective remediation techniques. The lack of affordable and effective cleanup technologies for explosives contamination requires the development of better processes. In this study, we present a system for TNT phytoremediation by overexpressing the old yellow enzyme (OYE3 gene from Saccharomyces cerevisiae. The resulting transgenic Arabidopsis plants demonstrated significantly enhanced TNT tolerances and a strikingly higher capacity to remove TNT from their media. The current work indicates that S. cerevisiae OYE3 overexpression in Arabidopsis is an efficient method for the phytoremoval and degradation of TNT. Our findings have the potential to provide a suitable remediation strategy for sites contaminated by TNT.

  4. Production of wax esters in plant seed oils by oleosomal cotargeting of biosynthetic enzymes[S

    Science.gov (United States)

    Heilmann, Mareike; Iven, Tim; Ahmann, Katharina; Hornung, Ellen; Stymne, Sten; Feussner, Ivo

    2012-01-01

    Wax esters are neutral lipids exhibiting desirable properties for lubrication. Natural sources have traditionally been whales. Additionally some plants produce wax esters in their seed oil. Currently there is no biological source available for long chain length monounsaturated wax esters that are most suited for industrial applications. This study aimed to identify enzymatic requirements enabling their production in oilseed plants. Wax esters are generated by the action of fatty acyl-CoA reductase (FAR), generating fatty alcohols and wax synthases (WS) that esterify fatty alcohols and acyl-CoAs to wax esters. Based on their substrate preference, a FAR and a WS from Mus musculus were selected for this study (MmFAR1 and MmWS). MmWS resides in the endoplasmic reticulum (ER), whereas MmFAR1 associates with peroxisomes. The elimination of a targeting signal and the fusion to an oil body protein yielded variants of MmFAR1 and MmWS that were cotargeted and enabled wax ester production when coexpressed in yeast or Arabidopsis. In the fae1 fad2 double mutant, rich in oleate, the cotargeted variants of MmFAR1 and MmWS enabled formation of wax esters containing >65% oleyl-oleate. The data suggest that cotargeting of unusual biosynthetic enzymes can result in functional interplay of heterologous partners in transgenic plants. PMID:22878160

  5. Plant characteristics associated with natural enemy abundance at Michigan native plants.

    Science.gov (United States)

    Fiedler, A K; Landis, D A

    2007-08-01

    Habitat management is a type of conservation biological control that focuses on increasing natural enemy populations by providing them with plant resources such as pollen and nectar. Insects are known to respond to a variety of plant characteristics in their search for plant-provided resources. A better understanding of the specific characteristics used by natural enemy insects in selecting these resources could greatly improve efficiency in screening plants for habitat management. We examined 5 previously tested and widely recommended resource plants and 43 candidate plants to test whether the number and type of natural enemies and herbivores at each plant were predicted by plant characteristics including: period of peak bloom, floral area, maximum flower height, hue, chroma, and corolla size. Natural enemy abundance increased with week of peak bloom and greater floral area across all plants tested. Ordination of plant characteristics indicated that increasing floral area, period of peak bloom, maximum flower height, and decreasing corolla width grouped together into a single principal component. Both natural enemy and herbivore abundance increased significantly with the principal component for this set of characteristics, but the relationship with herbivore abundance was weaker. These results indicate that, for a given time of the season, selection of plants with the largest floral area has potential to increase natural enemy abundance in habitat management plantings and streamline plant selection for habitat management.

  6. Cytochrome P450-Mediated Phytoremediation using Transgenic Plants: A Need for Engineered Cytochrome P450 Enzymes

    Science.gov (United States)

    Kumar, Santosh; Jin, Mengyao; Weemhoff, James L

    2013-01-01

    There is an increasing demand for versatile and ubiquitous Cytochrome P450 (CYP) biocatalysts for biotechnology, medicine, and bioremediation. In the last decade there has been an increase in realization of the power of CYP biocatalysts for detoxification of soil and water contaminants using transgenic plants. However, the major limitations of mammalian CYP enzymes are that they require CYP reductase (CPR) for their activity, and they show relatively low activity, stability, and expression. On the other hand, bacterial CYP enzymes show limited substrate diversity and usually do not metabolize herbicides and industrial contaminants. Therefore, there has been a considerable interest for biotechnological industries and the scientific community to design CYP enzymes to improve their catalytic efficiency, stability, expression, substrate diversity, and the suitability of P450-CPR fusion enzymes. Engineered CYP enzymes have potential for transgenic plants-mediated phytoremediation of herbicides and environmental contaminants. In this review we discuss: 1) the role of CYP enzymes in phytoremediation using transgenic plants, 2) problems associated with wild-type CYP enzymes in phytoremediation, and 3) examples of engineered CYP enzymes and their potential role in transgenic plant-mediated phytoremediation. PMID:25298920

  7. Alien invasive vascular plants in South African natural and semi-natural environments : bibliography from 1830

    CSIR Research Space (South Africa)

    Moran, VC

    1982-12-01

    Full Text Available stream_source_info Alien invasive vascular plants in South African natural and semi-natural environments.pdf.txt stream_content_type text/plain stream_size 47 Content-Encoding ISO-8859-1 stream_name Alien invasive vascular plants... in South African natural and semi-natural environments.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  8. Probabilities of Natural Events Occurring at Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.C.

    2001-07-17

    This report documents the comprehensive evaluation of probability models of natural events which are applicable to Savannah River Plant. The probability curves selected for these natural events are recommended to be used by all SRP/SRL safety analysts. This will ensure a consistency in analysis methodology for postulated SAR incidents involving natural phenomena.

  9. Deep Learning for Plant Identification in Natural Environment

    Directory of Open Access Journals (Sweden)

    Yu Sun

    2017-01-01

    Full Text Available Plant image identification has become an interdisciplinary focus in both botanical taxonomy and computer vision. The first plant image dataset collected by mobile phone in natural scene is presented, which contains 10,000 images of 100 ornamental plant species in Beijing Forestry University campus. A 26-layer deep learning model consisting of 8 residual building blocks is designed for large-scale plant classification in natural environment. The proposed model achieves a recognition rate of 91.78% on the BJFU100 dataset, demonstrating that deep learning is a promising technology for smart forestry.

  10. Rhizosphere stoichiometry: are C : N : P ratios of plants, soils, and enzymes conserved at the plant species-level?

    Science.gov (United States)

    Bell, Colin; Carrillo, Yolima; Boot, Claudia M; Rocca, Jennifer D; Pendall, Elise; Wallenstein, Matthew D

    2014-01-01

    As a consequence of the tight linkages among soils, plants and microbes inhabiting the rhizosphere, we hypothesized that soil nutrient and microbial stoichiometry would differ among plant species and be correlated within plant rhizospheres. We assessed plant tissue carbon (C) : nitrogen (N) : phosphorus (P) ratios for eight species representing four different plant functional groups in a semiarid grassland during near-peak biomass. Using intact plant species-specific rhizospheres, we examined soil C : N : P, microbial biomass C : N, and soil enzyme C : N : P nutrient acquisition activities. We found that few of the plant species' rhizospheres demonstrated distinct stoichiometric properties from other plant species and unvegetated soil. Plant tissue nutrient ratios and components of below-ground rhizosphere stoichiometry predominantly differed between the C4 plant species Buchloe dactyloides and the legume Astragalus laxmannii. The rhizospheres under the C4 grass B. dactyloides exhibited relatively higher microbial C and lower soil N, indicative of distinct soil organic matter (SOM) decomposition and nutrient mineralization activities. Assessing the ecological stoichiometry among plant species' rhizospheres is a high-resolution tool useful for linking plant community composition to below-ground soil microbial and nutrient characteristics. By identifying how rhizospheres differ among plant species, we can better assess how plant-microbial interactions associated with ecosystem-level processes may be influenced by plant community shifts.

  11. Saline soil enzyme activities of four plant communities in Sangong River basin of Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    ZhengJun GUAN; Qian LUO; Xi CHEN; XianWei FENG; ZhiXi TANG; Wei WEI; YuanRun ZHENG

    2014-01-01

    Soil enzyme activity plays an important role in the conversion of soil organic carbon into inorganic carbon, which is significant for the global carbon cycle. In this study, we investigated the soil enzyme activities of two ligninolytic enzymes (peroxidase and polyphenol oxidase) and five non-ligninolytic enzymes (α-1,4-glucosidase (AG); β-1,4-gluco-sidase (BG); N-acetyl-β-glucosaminidase (NAG); β-D-cellobiosidase (CBH); and β-xylosidase (BXYL)) in four plant communities of the Sangong River basin in Fukang, North Xinjiang, China. The four typical plant communities were dominated by Haloxylon ammodendron, Reaumuria soongonica, Salsola passerina, and Tamarix rarmosissima, respec-tively, with saline soils of varied alkalinity. The results showed that the soil peroxidase activity decreased seasonally. The activities of the five non-ligninolytic enzymes decreased with increasing soil depths, while those of the two ligninolytic enzymes did not show such a trend. In the four plant communities, BG had the highest activity among the five non-ligninolytic enzymes, and the activities of the two ligninolytic enzymes were higher than those of the four non-ligninolytic ones (AG, NAG, CBH, and BXYL). The community of H. ammodendron displayed the highest activity with respect to the two ligninolytic enzymes in most cases, but no significant differences were found among the four plant communities. The geometric mean of soil enzyme activities of the four plant communities was validated through an inde-pendently performed principal component analysis (PCA), which indicated that different plant communities had different soil enzyme activities. The correlation analysis showed that soil polyphenol oxidase activity was significantly positively correlated with the activities of the five non-ligninolytic enzymes. The soil pH value was positively correlated with the ac-tivities of al soil enzymes except peroxidase. Soil microbial carbon content also showed a significant positive

  12. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Berg, M.P.; Costa, S.R.; Putten, van der W.H.

    2007-01-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis

  13. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Berg, M.P.; Costa, S.R.; Putten, van der W.H.

    2007-01-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis

  14. Action of plant proteinase inhibitors on enzymes of physiopathological importance.

    Science.gov (United States)

    Oliva, Maria Luiza V; Sampaio, Misako U

    2009-09-01

    Obtained from leguminous seeds, various plant proteins inhibit animal proteinases, including human, and can be considered for the development of compounds with biological activity. Inhibitors from the Bowman-Birk and plant Kunitz-type family have been characterized by proteinase specificity, primary structure and reactive site. Our group mostly studies the genus Bauhinia, mainly the species bauhinioides, rufa, ungulata and variegata. In some species, more than one inhibitor was characterized, exhibiting different properties. Although proteins from this group share high structural similarity, they present differences in proteinase inhibition, explored in studies using diverse biological models.

  15. Using Plants to Explore the Nature & Structural Complexity of Life

    Science.gov (United States)

    Howard, Ava R.

    2014-01-01

    Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

  16. Using Plants to Explore the Nature & Structural Complexity of Life

    Science.gov (United States)

    Howard, Ava R.

    2014-01-01

    Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

  17. Plant-Derived Natural Products for Parkinson's Disease Therapy.

    Science.gov (United States)

    Sengupta, T; Vinayagam, J; Singh, R; Jaisankar, P; Mohanakumar, K P

    2016-01-01

    Plant-derived natural products have made their own niche in the treatment of neurological diseases since time immemorial. Parkinson's disease (PD), the second most prevalent neurodegenerative disorder, has no cure and the treatment available currently is symptomatic. This chapter thoughtfully and objectively assesses the scientific basis that supports the increasing use of these plant-derived natural products for the treatment of this chronic and progressive disorder. Proper considerations are made on the chemical nature, sources, preclinical tests and their validity, and mechanisms of behavioural or biochemical recovery observed following treatment with various plants derived natural products relevant to PD therapy. The scientific basis underlying the neuroprotective effect of 6 Ayurvedic herbs/formulations, 12 Chinese medicinal herbs/formulations, 33 other plants, and 5 plant-derived molecules have been judiciously examined emphasizing behavioral, cellular, or biochemical aspects of neuroprotection observed in the cellular or animal models of the disease. The molecular mechanisms triggered by these natural products to promote cell survivability and to reduce the risk of cellular degeneration have also been brought to light in this study. The study helped to reveal certain limitations in the scenario: lack of preclinical studies in all cases barring two; heavy dependence on in vitro test systems; singular animal or cellular model to establish any therapeutic potential of drugs. This strongly warrants further studies so as to reproduce and confirm these reported effects. However, the current literature offers scientific credence to traditionally used plant-derived natural products for the treatment of PD.

  18. Natural selection on plant physiological traits in an urban environment

    Science.gov (United States)

    Lambrecht, Susan C.; Mahieu, Stephanie; Cheptou, Pierre-Olivier

    2016-11-01

    Current rates of urbanization are creating new opportunities for studying urban plant ecology, but our knowledge of urban plant physiology lags behind that of other ecosystems. Moreover, higher temperatures, elevated CO2, and increased inorganic nitrogen deposition along with altered moisture regimes of urban as compared to rural areas creates a compelling analog for studying adaptations of plants to climate change. We grew plants under common conditions in a greenhouse to determine whether populations of Crepis sancta (Asteraceae) differed in phenological, morphological, and physiological traits. We also used a field experiment to test for natural selection on these traits in urban Montpellier, France. Urban plants flowered and senesced later than rural plants, and natural selection favored later phenology in the urban habitat. Natural selection also favored larger plants with more leaves, and increased photosynthesis and leaf nitrogen concentration. Ours is the first study to document selection on plant functional traits in an urban habitat and, as such, advances our understanding of urban plant ecology and possible adaptations to climate change.

  19. Aspergillus enzymes involved in degradation of plant cell wall polysaccharides

    NARCIS (Netherlands)

    Vries, de R.P.; Visser, J.

    2001-01-01

    Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a m

  20. Dyeing of wool fibres with natural dyes: effect of proteolytic enzymes.

    Science.gov (United States)

    Doğru, Mehmet; Baysal, Zübeyde; Aytekin, Cetin

    2006-01-01

    In spite of the widespread use of proteins (casein, peptone, etc.) and protein fragments as a substrate for the proteolytic enzymes, a substrate prepared from dyes that adsorb onto appropriate materials, such as wool and cotton, are also used for enzyme activity determination. In the point of view of this thought, it was our aim to develop the substrates which are easily and economically obtainable and also environmentally safer for the frequently used proteolytic enzymes, such as subtilisin carlsberg, trypsin, chymotrypsin, and protease type XVI and, if possible, to prepare the specific substrate at least for one of these enzymes. For this aim, wool was dyed with natural dyes such as juglone, lawsone, berberine, and quercetin. The optimum pH, incubation time, and agitation rate were determinated. The results indicate that, of all the tested enzymes on wool-dye complex as an insoluble substrate, the most appropriate complex was found to be wool-lawsone complex.

  1. Natural rubber biosynthesis in plants: rubber transferase.

    Science.gov (United States)

    Cornish, Katrina; Xie, Wenshuang

    2012-01-01

    Rubber biosynthesis in plants is a fascinating biochemical system, which evolved at the dawn of the dicotyledoneae and is present in at least four of the dictolydonous superorders. Rubber biosynthesis is catalyzed by a membrane complex in a monolayer membrane envelope, requires two distinct substrates and a divalent cation cofactor, and produces a high-molecular-weight isoprenoid polymer. A solid understanding of this system underpins valuable papers in the literature. However, the published literature is rife with unreliable reports in which the investigators have fallen into traps created by the current incomplete understanding of the biochemistry of rubber synthesis. In this chapter, we attempt to guide both new and more established researchers around these pitfalls.

  2. REE bound DNA in natural plant

    Institute of Scientific and Technical Information of China (English)

    王玉琦; 江平; 郭繁清; 张智勇; 孙景信; 许雷; 曹国印

    1999-01-01

    The binding of rare earth elements (REEs) with nucleic acids in the leaves of fern Dicranopteris dichotoma (DD) has been studied by molecular activation analysis (MAA). The REEs bound DNA (REE-DNA) was obtained from the leaves of DD. The CTAB-based procedure was modified for extraction of total DNA. The purity of DNA was examined by UV spectroscopy. The DNA obtained was separated and determined by agarose gel electrophoresis further. Meanwhile, the contents of eight rare earth elements (La, Ce, Nd, Sm, Eu,Tb, Yb and Lu) in REE-DNA were detected by instrumental neutron activation analysis (INAA). The results showed that REE-DNA with higher purity could be extracted from plant using this method. It was also found that REEs were bound firmly with DNA in the leaves of DD. The molecular weight (MW) of REE-DNA band was about 22 kb in agarose gel electrophoresis.

  3. Managing invasive plants in natural areas: Moving beyond weed control

    Science.gov (United States)

    Dean Pearson; Yvette Ortega

    2009-01-01

    Exotic invasive plants present one of the greatest challenges to natural resource management. These weeds can alter entire communities and ecosystems, substantially degrading important ecosystem services such as forage for wild and domestic herbivores, water and soil quality, recreational values, and wildlife habitat. Traditionally, weed management in natural areas has...

  4. Natural enemies drive geographic variation in plant defenses

    DEFF Research Database (Denmark)

    Zuest, Tobias; Heichinger, Christian; Grossniklaus, Ueli

    2012-01-01

    Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources o...

  5. Endophytes from an Australian native plant are a promising source of industrially useful enzymes.

    Science.gov (United States)

    Zaferanloo, Bita; Virkar, Aditya; Mahon, Peter J; Palombo, Enzo A

    2013-02-01

    Endophytes are microorganisms that live within plant tissues that are potential sources of novel bioactive compounds, including enzymes. We have identified endophytes of the Australian native plant Eremophilia longifolia which were screened for the production of industrially useful enzymes. Seventeen fungal endophytes were isolated from the leaves of E. longifolia and enzyme production was investigated within a range of pH (3.5, 5.5, 7 and 9) and temperatures (9, 25, 37 and 50 °C). Amylase was the most common enzyme encountered with numerous isolates showing production throughout the temperature and pH ranges. Protease production was also seen over the conditions tested but was more dominant at lower pH and temperature. Activity was not observed for other enzymes including ligninase, xylanase and cellobiohydrolase. Enzymes from isolates of Preussia minima, Alternaria sp. and an unclassified fungus, which showed highest activity in screening assays, were investigated further. Enzyme production was verified by zymography and the amylase activity of P. minima was found to be significantly greater than that of Aspergillus oryzae particularly in alkaline conditions and low temperature which are desirable properties for the detergent industry. This work shows that enzymes with potential use in industry can be readily identified in fungal endophytes.

  6. NATURAL PLANT TOXICANT – CYANOGENIC GLYCOSIDE AMYGDALIN: CHARACTERISTIC, METABOLISM AND THE EFFECT ON ANIMAL REPRODUCTION

    Directory of Open Access Journals (Sweden)

    Eduard Kolesár

    2015-02-01

    Full Text Available The amount of cyanogenic glycosides, as natural plant toxicants, in plants varies with plant species and environmental effects. Cyanogenic glycoside as an amygdalin was detected in apricot kernels, bitter almonds and peach, plum, pear and apple seeds. Amygdalin itself is non-toxic, but its HCN production decomposed by some enzymes is toxic substance. Target of this review was to describe the characteristic, metabolism and possible effects of amygdalin on reproductive processes. Previous studies describe the effects of natural compound amygdalin on female and male reproductive systems focused on process of steroidogenesis, spermatozoa motility and morphological abnormalities of spermatozoa. In accordance to the previous studies on amygdalin its benefit is controversial.

  7. Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes.

    Science.gov (United States)

    Habib, Sheikh Hasna; Kausar, Hossain; Saud, Halimi Mohd

    2016-01-01

    Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT) and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR) were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress.

  8. Natural plant genetic engineer Agrobacterium rhizogenes: role of T-DNA in plant secondary metabolism.

    Science.gov (United States)

    Chandra, Sheela

    2012-03-01

    Agrobacterium rhizogenes is a natural plant genetic engineer. It is a gram-negative soil bacterium that induces hairy root formation. Success has been obtained in exploring the molecular mechanisms of transferred DNA (T-DNA) transfer, interaction with host plant proteins, plant defense signaling and integration to plant genome for successful plant genetic transformation. T-DNA and corresponding expression of rol genes alter morphology and plant host secondary metabolism. During transformation, there is a differential loss of a few T-DNA genes. Loss of a few ORFs drastically affect the growth and morphological patterns of hairy roots, expression pattern of biosynthetic pathway genes and accumulation of specific secondary metabolites.

  9. Something Old, Something New: Conserved Enzymes and the Evolution of Novelty in Plant Specialized Metabolism.

    Science.gov (United States)

    Moghe, Gaurav D; Last, Robert L

    2015-11-01

    Plants produce hundreds of thousands of small molecules known as specialized metabolites, many of which are of economic and ecological importance. This remarkable variety is a consequence of the diversity and rapid evolution of specialized metabolic pathways. These novel biosynthetic pathways originate via gene duplication or by functional divergence of existing genes, and they subsequently evolve through selection and/or drift. Studies over the past two decades revealed that diverse specialized metabolic pathways have resulted from the incorporation of primary metabolic enzymes. We discuss examples of enzyme recruitment from primary metabolism and the variety of paths taken by duplicated primary metabolic enzymes toward integration into specialized metabolism. These examples provide insight into processes by which plant specialized metabolic pathways evolve and suggest approaches to discover enzymes of previously uncharacterized metabolic networks.

  10. Something Old, Something New: Conserved Enzymes and the Evolution of Novelty in Plant Specialized Metabolism1

    Science.gov (United States)

    Moghe, Gaurav D.; Last, Robert L.

    2015-01-01

    Plants produce hundreds of thousands of small molecules known as specialized metabolites, many of which are of economic and ecological importance. This remarkable variety is a consequence of the diversity and rapid evolution of specialized metabolic pathways. These novel biosynthetic pathways originate via gene duplication or by functional divergence of existing genes, and they subsequently evolve through selection and/or drift. Studies over the past two decades revealed that diverse specialized metabolic pathways have resulted from the incorporation of primary metabolic enzymes. We discuss examples of enzyme recruitment from primary metabolism and the variety of paths taken by duplicated primary metabolic enzymes toward integration into specialized metabolism. These examples provide insight into processes by which plant specialized metabolic pathways evolve and suggest approaches to discover enzymes of previously uncharacterized metabolic networks. PMID:26276843

  11. Alpha-Glucosidase Enzyme Biosensor for the Electrochemical Measurement of Antidiabetic Potential of Medicinal Plants

    Science.gov (United States)

    Mohiuddin, M.; Arbain, D.; Islam, A. K. M. Shafiqul; Ahmad, M. S.; Ahmad, M. N.

    2016-02-01

    A biosensor for measuring the antidiabetic potential of medicinal plants was developed by covalent immobilization of α-glucosidase (AG) enzyme onto amine-functionalized multi-walled carbon nanotubes (MWCNTs-NH2). The immobilized enzyme was entrapped in freeze-thawed polyvinyl alcohol (PVA) together with p-nitrophenyl-α- d-glucopyranoside (PNPG) on the screen-printed carbon electrode at low pH to prevent the premature reaction between PNPG and AG enzyme. The enzymatic reaction within the biosensor is inhibited by bioactive compounds in the medicinal plant extracts. The capability of medicinal plants to inhibit the AG enzyme on the electrode correlates to the potential of the medicinal plants to inhibit the production of glucose from the carbohydrate in the human body. Thus, the inhibition indicates the antidiabetic potential of the medicinal plants. The performance of the biosensor was evaluated to measure the antidiabetic potential of three medicinal plants such as Tebengau ( Ehretis laevis), Cemumar ( Micromelum pubescens), and Kedondong ( Spondias dulcis) and acarbose (commercial antidiabetic drug) via cyclic voltammetry, amperometry, and spectrophotometry. The cyclic voltammetry (CV) response for the inhibition of the AG enzyme activity by Tebengau plant extracts showed a linear relation in the range from 0.423-8.29 μA, and the inhibition detection limit was 0.253 μA. The biosensor exhibited good sensitivity (0.422 μA/mg Tebengau plant extracts) and rapid response (22 s). The biosensor retains approximately 82.16 % of its initial activity even after 30 days of storage at 4 °C.

  12. Monoclonal Antibody-Based Enzyme Linked Immunosorbent Assay for the Analysis of Jasmonates in Plants

    Institute of Scientific and Technical Information of China (English)

    Aixing Deng; Weiming Tan; Suping He; Wei Liu; Tiegui Nan; Zhaohu Li; Baomin Wang; Qing X.Li

    2008-01-01

    Methyl jasmonate (MeJA) and its free-acid form,jasmonic acid (JA) are naturally occurring plant growth regulators widely distributed in higher plants.In order to improve the sensitivity for the analysis of MeJA at low levels in small amounts of plant samples,a monoclonal antibody (MAb) (designated as MAb 3E5D7C4B6) against MeJA was derived from a JAbovine serum albumin (BSA) conjugate as an immunogen.The antibody belongs to the IgG1 subclass with a κ type light chain and has a dissociation constant of approximately 6.07 x 10-9 M.MAb3E5D7C4B6 is very specific to MeJA.It was used to develop a direct competitive enzyme-linked immunosorbent assay (dcELISA),conventional and simplified indirect competitive ELISAs (icELISA).JA was derivatized into MeJA for the ELISA analysis.The IC50 value and detection range for MeJA were,respectively,34 and 4-257 ng/mL by the conventional icELISA,21 and 3-226 ng/mL by the simplified icELISA and 5.0 and 0.7-97.0 ng/mL by the dcELISA.The dcELISA was more sensitive than either the conventional or simplified icELISA.The assays were used to measure the content of jasmonates as MeJA in tobacco leaves under drought stress or inoculated with tobacco mosaic virus and tomato leaves inoculated with tomato mosaic virus or Lirioinyza sativae Blanchard as compared with the corresponding healthy leaves.The increased jasmonates content indicated its role in response to the drought stress and pathogens.

  13. Action of plant proteinase inhibitors on enzymes of physiopathological importance

    Directory of Open Access Journals (Sweden)

    Maria Luiza V. Oliva

    2009-09-01

    Full Text Available Obtained from leguminous seeds, various plant proteins inhibit animal proteinases, including human, and can be considered for the development of compounds with biological activity. Inhibitors from the Bowman-Birk and plant Kunitz-type family have been characterized by proteinase specificity, primary structure and reactive site. Our group mostly studies the genus Bauhinia, mainly the species bauhinioides, rufa, ungulata and variegata. In some species, more than one inhibitor was characterized, exhibiting different properties. Although proteins from this group share high structural similarity, they present differences in proteinase inhibition, explored in studies using diverse biological models.Obtidas de sementes leguminosas, várias proteínas inibem proteinases de origem animal, incluindo humanas, e podem ser consideradas para o desenvolvimento de compostos com atividade biológica. Inibidores da família Bowman-Birk e da família Kunitz vegetal tem sido caracterizados em relação a especificidade para proteinase, estrutura primária e sitio reativo. O nosso grupo majoritariamente vem estudando o gênero Bauhinia, principalmente as espécies bauhinioides, rufa, ungulatae variegata. Em algumas espécies, mais de um inibidor com propriedades diferentes foi caracterizado. Embora tais proteínas apresentem alta similaridade estrutural, diferem quanto à inibição de proteinases, e foram exploradas em estudos utilizando diversos modelos biológicos.

  14. Several genes encoding enzymes with the same activity are necessary for aerobic fungal degradation of cellulose in nature.

    Directory of Open Access Journals (Sweden)

    Peter K Busk

    Full Text Available The cellulose-degrading fungal enzymes are glycoside hydrolases of the GH families and lytic polysaccharide monooxygenases. The entanglement of glycoside hydrolase families and functions makes it difficult to predict the enzymatic activity of glycoside hydrolases based on their sequence. In the present study we further developed the method Peptide Pattern Recognition to an automatic approach not only to find all genes encoding glycoside hydrolases and lytic polysaccharide monooxygenases in fungal genomes but also to predict the function of the genes. The functional annotation is an important feature as it provides a direct route to predict function from primary sequence. Furthermore, we used Peptide Pattern Recognition to compare the cellulose-degrading enzyme activities encoded by 39 fungal genomes. The results indicated that cellobiohydrolases and AA9 lytic polysaccharide monooxygenases are hallmarks of cellulose-degrading fungi except brown rot fungi. Furthermore, a high number of AA9, endocellulase and β-glucosidase genes were identified, not in what are known to be the strongest, specialized lignocellulose degraders but in saprophytic fungi that can use a wide variety of substrates whereas only few of these genes were found in fungi that have a limited number of natural, lignocellulotic substrates. This correlation suggests that enzymes with different properties are necessary for degradation of cellulose in different complex substrates. Interestingly, clustering of the fungi based on their predicted enzymes indicated that Ascomycota and Basidiomycota use the same enzymatic activities to degrade plant cell walls.

  15. Spatial distribution of enzyme activities along the root and in the rhizosphere of different plants

    Science.gov (United States)

    Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    Extracellular enzymes are important for decomposition of many biological macromolecules abundant in soil such as cellulose, hemicelluloses and proteins. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. So far acquisition of in situ data about local activity of different enzymes in soil has been challenged. That is why there is an urgent need in spatially explicit methods such as 2-D zymography to determine the variation of enzymes along the roots in different plants. Here, we developed further the zymography technique in order to quantitatively visualize the enzyme activities (Spohn and Kuzyakov, 2013), with a better spatial resolution We grew Maize (Zea mays L.) and Lentil (Lens culinaris) in rhizoboxes under optimum conditions for 21 days to study spatial distribution of enzyme activity in soil and along roots. We visualized the 2D distribution of the activity of three enzymes:β-glucosidase, leucine amino peptidase and phosphatase, using fluorogenically labelled substrates. Spatial resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography shows different pattern of spatial distribution of enzyme activity along roots and soil of different plants. We observed a uniform distribution of enzyme activities along the root system of Lentil. However, root system of Maize demonstrated inhomogeneity of enzyme activities. The apical part of an individual root (root tip) in maize showed the highest activity. The activity of all enzymes was the highest at vicinity of the roots and it decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify

  16. Natural occurrence of mycotoxins in medicinal plants: a review.

    Science.gov (United States)

    Ashiq, Samina; Hussain, Mubbashir; Ahmad, Bashir

    2014-05-01

    Medicinal plants are widely used as home remedies and raw materials for the pharmaceutical industries. Herbal remedies are used in the prevention, treatment and cure of disorders and diseases since ancient times. However, use of medicinal herbs may not meet the requirements of quality, safety and efficacy. During harvesting, handling, storage and distribution, medicinal plants are subjected to contamination by various fungi, which may be responsible for spoilage and production of mycotoxins. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity and quality of these natural products. The increase in use of medicinal plants may lead to an increase in the intake of mycotoxins therefore contamination of medicinal plants with mycotoxins can contribute to adverse human health problems and therefore represents a special hazard. Numerous natural occurrences of mycotoxins in medicinal plants and traditional herbal medicines have been reported from various countries including Spain, China, Germany, India, Turkey and from Middle East as well. This review discusses the important mycotoxins and their natural occurrences in medicinal plants and their products.

  17. Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Rogowska-Wrzesinska, Adelina; Hoffmann, Daniel;

    2014-01-01

    upregulated in the gongylidia, specialized hyphal tips whose only known function is to provide food to the ants. These combined results indicate that the enzymes are derived from the ingested fungal tissues. We infer that the five proteases are likely to accelerate protein extraction from plant cells...... in the leaf pulp that the ants add to the fungus garden, but regulatory functions such as activation of proenzymes are also possible, particularly for the aspartic proteases that were present but without showing activity. The proteases had high sequence similarities to proteolytic enzymes of phytopathogenic...... fungi, consistent with previous indications of convergent evolution of decomposition enzymes in attine ant fungal symbionts and phytopathogenic fungi....

  18. The metal effect on the Polyphenol oxidase enzyme from borage(Trachystemon orientalis plant

    Directory of Open Access Journals (Sweden)

    Esma Hande Alıcı

    2013-06-01

    Full Text Available In this study, Polyphenol oxidase was extracted from Borage plant (Trachystemon orientalis and the crude extract was used for the assays. Its pH and temperature optima for 4-methyl cathecol were 5.0 and 5°C, respectively. Km of this enzyme was 4.55 mM for 4-methyl cathecol. We also found that the enzyme was activated by Fe3+, Mg2+, Zn2+, Cu2+, Ca2+, K+, but inhibited by Hg2+, Mn2+, Ni2+, Sn2+, Na+. Ba2+, Al3+ and Pb2+ metal ions both activated and inhibited the enzyme at different concentrations.

  19. Plant diversity associated with pools in natural and restored peatlands

    Directory of Open Access Journals (Sweden)

    N. Fontaine

    2007-06-01

    Full Text Available This study describes plant assemblages associated with the edges of peatland pools. We conducted inventories in six natural peatlands in the province of Québec (Canada in order to measure the contribution of pools to species diversity in climatic regions where peatlands are used for peat extraction. We also carried out vegetation surveys in a peatland that has been restored after peat extraction/harvesting to determine whether pool vegetation establishes along the edges of created pools when dry surface restoration techniques only are used. Pools enhanced plant species richness in natural peatlands. Around created pools, species associated with natural pools were still absent, and non-bog species were present, six years after restoration. On this basis, we emphasise the importance of preserving natural peatlands with pools. In order to restore fully the plant diversity associated with peatlands at harvested sites, it may be necessary to modify pool excavation techniques so that created pools resemble more closely those in natural peatlands. Active introduction of the plant species or communities associated with natural pools may also be needed; candidate species for North America include Andromeda glaucophylla, Cladopodiella fluitans, Carex limosa, Eriophorum virginicum, Rhynchospora alba and Sphagnum cuspidatum.

  20. A systematic approach to discover and characterize natural plant biostimulants

    Directory of Open Access Journals (Sweden)

    Giovanni ePovero

    2016-04-01

    Full Text Available The use of natural plant biostimulants is proposed as an innovative solution to address the challenges to sustainable agriculture, to ensure optimal nutrient uptake, crop yield, quality, and tolerance to abiotic stress. However, the process of selection and characterization of plant biostimulant matrices is complex and involves a series of rigorous evaluations customized to the needs of the plant.Here, we propose a highly differentiated plant biostimulant development and production platform, which involves a combination of technology, processes, and know-how. Chemistry, biology and omic concepts are combined/integrated to investigate and understand the specific mode(s of action of bioactive ingredients. The proposed approach allows to predict and characterize the function of natural compounds as biostimulants. By managing and analyzing massive amounts of complex data, it is therefore possible to discover, evaluate and validate new product candidates, thus expanding the uses of existing products to meet the emerging needs of agriculture.

  1. Plant extracts as natural antioxidants in meat and meat products.

    Science.gov (United States)

    Shah, Manzoor Ahmad; Bosco, Sowriappan John Don; Mir, Shabir Ahmad

    2014-09-01

    Antioxidants are used to minimize the oxidative changes in meat and meat products. Oxidative changes may have negative effects on the quality of meat and meat products, causing changes in their sensory and nutritional properties. Although synthetic antioxidants have already been used but in recent years, the demand for natural antioxidants has been increased mainly because of adverse effects of synthetic antioxidants. Thus most of the recent investigations have been directed towards the identification of natural antioxidants from various plant sources. Plant extracts have been prepared using different solvents and extraction methods. Grape seed, green tea, pine bark, rosemary, pomegranate, nettle and cinnamon have exhibited similar or better antioxidant properties compared to some synthetic ones. This review provides the recent information on plant extracts used as natural antioxidants in meat and meat products, specifically red meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Nickel hyperaccumulation by natural plants in Turkish serpentine soils

    OpenAIRE

    ALTINÖZLÜ, Haşim; KARAGÖZ, Alptekin; POLAT, Turgay; Ünver, İlhami

    2014-01-01

    Natural plants in Turkish serpentine soils were surveyed to determine their Ni accumulation capability. Geographic distribution and diethylene triamine pentaacetic acid (DTPA)-extractable nickel contents of the western Anatolian serpentine soils and their vegetative contents were studied to find the possible relationships between the phytoavailable Ni amount in the soil and the Ni content of potential accumulator plants. Over half of the surface area of Turkey was targeted in the study. Above...

  3. Plant-mediated interactions between whiteflies, herbivores, and natural enemies.

    Science.gov (United States)

    Inbar, Moshe; Gerling, Dan

    2008-01-01

    Whiteflies (Homoptera: Aleyrodidae) comprise tiny phloem-sucking insects. The sessile development of their immatures and their phloem-feeding habits (with minimal physical plant damage) often lead to plant-mediated interactions with other organisms. The main data come from the polyphagous pest species Bemisia tabaci (Gennadius) and Trialeurodes vaporariorum (Westwood), which are intricately associated with their host plants. Although these associations might not represent aleyrodids in general, we rely on them to highlight the fundamental role of host plants in numerous ecological interactions between whiteflies, other herbivores, and their natural enemies. Plant traits often affect the activity, preference, and performance of the whiteflies, as well as their entomopathogens, predators, and parasitoids. Leaf structure (primarily pubescence) and constitutive and induced chemical profiles (defensive and nutritional elements) are critically important determinants of whitefly fitness. Pest management-related and evolutionary biology studies could benefit from future research that will consider whiteflies in a multitrophic-level framework.

  4. Genome modifications in plant cells by custom-made restriction enzymes.

    Science.gov (United States)

    Tzfira, Tzvi; Weinthal, Dan; Marton, Ira; Zeevi, Vardit; Zuker, Amir; Vainstein, Alexander

    2012-05-01

    Genome editing, i.e. the ability to mutagenize, insert, delete and replace sequences, in living cells is a powerful and highly desirable method that could potentially revolutionize plant basic research and applied biotechnology. Indeed, various research groups from academia and industry are in a race to devise methods and develop tools that will enable not only site-specific mutagenesis but also controlled foreign DNA integration and replacement of native and transgene sequences by foreign DNA, in living plant cells. In recent years, much of the progress seen in gene targeting in plant cells has been attributed to the development of zinc finger nucleases and other novel restriction enzymes for use as molecular DNA scissors. The induction of double-strand breaks at specific genomic locations by zinc finger nucleases and other novel restriction enzymes results in a wide variety of genetic changes, which range from gene addition to the replacement, deletion and site-specific mutagenesis of endogenous and heterologous genes in living plant cells. In this review, we discuss the principles and tools for restriction enzyme-mediated gene targeting in plant cells, as well as their current and prospective use for gene targeting in model and crop plants.

  5. Plant cell culture strategies for the production of natural products.

    Science.gov (United States)

    Ochoa-Villarreal, Marisol; Howat, Susan; Hong, SunMi; Jang, Mi Ok; Jin, Young-Woo; Lee, Eun-Kyong; Loake, Gary J

    2016-03-01

    Plants have evolved a vast chemical cornucopia to support their sessile lifestyles. Man has exploited this natural resource since Neolithic times and currently plant-derived chemicals are exploited for a myriad of applications. However, plant sources of most high-value natural products (NPs) are not domesticated and therefore their production cannot be undertaken on an agricultural scale. Further, these plant species are often slow growing, their populations limiting, the concentration of the target molecule highly variable and routinely present at extremely low concentrations. Plant cell and organ culture constitutes a sustainable, controllable and environmentally friendly tool for the industrial production of plant NPs. Further, advances in cell line selection, biotransformation, product secretion, cell permeabilisation, extraction and scale-up, among others, are driving increases in plant NP yields. However, there remain significant obstacles to the commercial synthesis of high-value chemicals from these sources. The relatively recent isolation, culturing and characterisation of cambial meristematic cells (CMCs), provides an emerging platform to circumvent many of these potential difficulties. [BMB Reports 2016; 49(3): 149-158].

  6. Modulation of Banana Polyphenol Oxidase (Ppo Activity by Naturally Occurring Bioactive Compounds From Plant Extracts

    Directory of Open Access Journals (Sweden)

    Alamelumangai. M

    2015-01-01

    Full Text Available Polyphenol Oxidase (PPO (E.C number 1.14.18.1 was extracted from banana (Musa paradisiaca and partially purified by acetone precipitation. The enzyme was found to have high affinity towards its substrate, catechol. In this study, various plant extracts like Glycyrrhiza glabra, Rubia cordifolia, Hesperethusa crenulata and oil from the seeds of Hydnocarpus laurifolia were observed to modulate the activity of banana PPO. Method In this study, various plant extracts were observed to modulate the activity of banana PPO at two different concentrations (0.4 and 40 μg/ml concentrations Result Among these 4 plant extracts, Glycyrrhiza glabra and Rubia cordifolia were found to increase the activity of PPO up to 1.35- 2.7 fold at two different concentrations (4 and 40 μg/ml. Few other two samples like Chaulmogra oil (2 and 4 μl/ml and the Hesperethusa crenulata plant extract (0.4 and 40 μg/ml concentrations, when used at low concentrations decreased the enzyme activity (38 %. Conclusion The novelty of this study is to screen their naturally occurring bioactive compounds from the plant extracts and their inhibitory activity against PPO.

  7. Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass.

    Science.gov (United States)

    Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves; Alberti, Adriana; Weissenbach, Jean; Salanoubat, Marcel; Tolonen, Andrew C

    2014-11-01

    Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme) assays, RNA sequencing (RNA-seq), and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass.

  8. Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass.

    Directory of Open Access Journals (Sweden)

    Magali Boutard

    2014-11-01

    Full Text Available Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme assays, RNA sequencing (RNA-seq, and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass.

  9. Prospects for using combined engineered bacterial enzymes and plant systems to rhizoremediate polychlorinated biphenyls.

    Science.gov (United States)

    Sylvestre, Michel

    2013-03-01

    The fate of polychlorinated biphenyls (PCBs) in soil is driven by a combination of interacting biological processes. Several investigations have brought evidence that the rhizosphere provides a remarkable ecological niche to enhance the PCB degradation process by rhizobacteria. The bacterial oxidative enzymes involved in PCB degradation have been investigated extensively and novel engineered enzymes exhibiting enhanced catalytic activities toward more persistent PCBs have been described. Furthermore, recent studies suggest that approaches involving processes based on plant-microbe associations are very promising to remediate PCB-contaminated sites. In this review emphasis will be placed on the current state of knowledge regarding the strategies that are proposed to engineer the enzymes of the PCB-degrading bacterial oxidative pathway and to design PCB-degrading plant-microbe systems to remediate PCB-contaminated soil.

  10. An ecological cost of plant defence : attractiveness of bitter cucumber plants to natural enemies of herbivores

    NARCIS (Netherlands)

    Agrawal, A.A.; Janssen, A.; Bruin, J.; Posthumus, M.A.; Sabelis, M.W.

    2002-01-01

    Plants produce defences that act directly on herbivores and indirectly via the attraction of natural enemies of herbivores. We examined the pleiotropic effects of direct chemical defence production on indirect defence employing near-isogenic varieties of cucumber plants (Cucumis sativus) that differ

  11. Enzyme directed formation of un-natural side-chains for covalent surface attachment of proteins.

    Science.gov (United States)

    Cho, Hwayoung; Jaworski, Justyn

    2014-10-01

    The covalent immobilization of proteins onto surfaces is an essential aspect of several fields of research, including proteomics, sensing, heterogeneous biocatalysis, and more broadly biotechnology. Site-specific, covalent attachment of proteins has been achieved in recent years by the use of expanded genetic codes to produce proteins with controlled placement of un-natural amino acids bearing bio-orthogonal functional groups. Unfortunately, the complexity of developing such systems is impractical for most laboratories; hence, a less complicated approach to generating un-natural amino acid side-chains has been employed. Utilizing a straightforward reaction with formylglycine generating enzyme, we use the site-specific modification of engineered proteins to yield un-natural amino acid side-chains for protein immobilization. Using this approach, we demonstrate the controlled immobilization of various enzymes onto a variety of amine coated surfaces. Our results reveal reusability of the immobilized enzymes via this strategy, and furthermore, we find the activity of the immobilized enzymes to remain even after a month of use indicating significant stability of the linkage.

  12. Potential Antivirals: Natural Products Targeting Replication Enzymes of Dengue and Chikungunya Viruses

    Directory of Open Access Journals (Sweden)

    Ana Flávia Costa da Silveira Oliveira

    2017-03-01

    Full Text Available Dengue virus (DENV and chikungunya virus (CHIKV are reemergent arboviruses that are transmitted by mosquitoes of the Aedes genus. During the last several decades, these viruses have been responsible for millions of cases of infection and thousands of deaths worldwide. Therefore, several investigations were conducted over the past few years to find antiviral compounds for the treatment of DENV and CHIKV infections. One attractive strategy is the screening of compounds that target enzymes involved in the replication of both DENV and CHIKV. In this review, we describe advances in the evaluation of natural products targeting the enzymes involved in the replication of these viruses.

  13. EFFECT OF NATURAL PLANT EXTRACTS ON PORCINE OVARIAN FUNCTIONS

    Directory of Open Access Journals (Sweden)

    Attila Kádasi

    2015-02-01

    Full Text Available This report provides information about the impact of chosen natural plant extracts on basic ovarian functions. This article summarizes our results concerning the effect of selected plant extracts on proliferation, apoptosis and hormone secretion – release of progesterone (P4, testosterone (T and leptin (L on porcine granulosa cells (GC, We analyzed effects of ginkgo (GB, rooibos (RB, flaxseed (FL, green tea polyphenols (GTPP, green tea - epigallocatechin-3-gallate (EGCG, resveratrol (RSV and curcumin (CURC (0; 1; 10 and 100 μg.ml-1 on markers of proliferation, apoptosis and secretory activity of porcine ovarian granulosa cells by using immunocytochemistry and EIA. It was demonstrated, that all these natural plants and plant molecules inhibited the accumulation of proliferation-related peptide (PCNA and apoptosis-associated peptide (Bax in cultured. Furthermore, it was observed that natural plant extracts altered progesterone, testosterone and leptin release in porcine ovarian cells. It is concluded, that GB, RB, FL, RSV, CURC, GTPP and EGCG can directly affect ovarian cells and therefore they could potentially influence ovarian functions.

  14. An efficient treatment for detoxification process of cassava starch by plant cell wall-degrading enzymes.

    Science.gov (United States)

    Sornyotha, Somphit; Kyu, Khin Lay; Ratanakhanokchai, Khanok

    2010-01-01

    The objective of this work was to remove linamarin in starch from cassava (Manihot esculenta Crantz cv. KU-50) roots, a high-cyanogen variety by using plant cell wall-degrading enzymes, xylanase and cellulase. The combination of xylanase from Bacillus firmus K-1 and xylanase and cellulase from Paenibacillus curdlanolyticus B-6 at the ratio of 1:9 showed the maximum synergism at 1.8 times for hydrolyzing cassava cortex cell walls and releasing linamarase. Combined enzyme treatment enhanced linamarin liberation from the parenchyma by 90%. In addition, when the combined enzymes were applied for detoxification during cassava starch production, a low-cyanide-product was obtained with decreased linamarin concentration (96%) compared to non-enzyme treated tissues. Based on these results, xylanase and cellulase treatment is a good method for low-cyanide-cassava starch production and could be applied for detoxification of cassava products during processing.

  15. Convergent evolution of caffeine in plants by co-option of exapted ancestral enzymes.

    Science.gov (United States)

    Huang, Ruiqi; O'Donnell, Andrew J; Barboline, Jessica J; Barkman, Todd J

    2016-09-20

    Convergent evolution is a process that has occurred throughout the tree of life, but the historical genetic and biochemical context promoting the repeated independent origins of a trait is rarely understood. The well-known stimulant caffeine, and its xanthine alkaloid precursors, has evolved multiple times in flowering plant history for various roles in plant defense and pollination. We have shown that convergent caffeine production, surprisingly, has evolved by two previously unknown biochemical pathways in chocolate, citrus, and guaraná plants using either caffeine synthase- or xanthine methyltransferase-like enzymes. However, the pathway and enzyme lineage used by any given plant species is not predictable from phylogenetic relatedness alone. Ancestral sequence resurrection reveals that this convergence was facilitated by co-option of genes maintained over 100 million y for alternative biochemical roles. The ancient enzymes of the Citrus lineage were exapted for reactions currently used for various steps of caffeine biosynthesis and required very few mutations to acquire modern-day enzymatic characteristics, allowing for the evolution of a complete pathway. Future studies aimed at manipulating caffeine content of plants will require the use of different approaches given the metabolic and genetic diversity revealed by this study.

  16. From Agrobacterium to viral vectors: genome modification of plant cells by rare cutting restriction enzymes.

    Science.gov (United States)

    Marton, Ira; Honig, Arik; Omid, Ayelet; De Costa, Noam; Marhevka, Elena; Cohen, Barry; Zuker, Amir; Vainstein, Alexander

    2013-01-01

    Researchers and biotechnologists require methods to accurately modify the genome of higher eukaryotic cells. Such modifications include, but are not limited to, site-specific mutagenesis, site-specific insertion of foreign DNA, and replacement and deletion of native sequences. Accurate genome modifications in plant species have been rather limited, with only a handful of plant species and genes being modified through the use of early genome-editing techniques. The development of rare-cutting restriction enzymes as a tool for the induction of site-specific genomic double-strand breaks and their introduction as a reliable tool for genome modification in animals, animal cells and human cell lines have paved the way for the adaptation of rare-cutting restriction enzymes to genome editing in plant cells. Indeed, the number of plant species and genes which have been successfully edited using zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and engineered homing endonucleases is on the rise. In our review, we discuss the basics of rare-cutting restriction enzyme-mediated genome-editing technology with an emphasis on its application in plant species.

  17. Screening of Zulu medicinal plants for angiotensin converting enzyme (ACE) inhibitors.

    Science.gov (United States)

    Duncan, A C; Jäger, A K; van Staden, J

    1999-12-15

    Twenty plants used by traditional healers in South Africa for the treatment of high blood pressure were investigated for their anti-hypertensive properties, utilizing the angiotensin converting enzyme assay. A hit rate of 65% was achieved, with the highest inhibition (97%) obtained by Adenopodia spicata leaves. A further seven plants exhibited an inhibition greater than 70% and five more over 50%. The leaves of the plants showed the greatest levels of inhibition. There was little difference in the overall hit rate between ethanolic and aqueous extracts, although in most cases there was a marked difference in activity between aqueous and ethanolic extracts from the same species. Plants exhibiting inhibition levels greater than 50% were further tested for the presence of tannins in order to eliminate possible false positives. Active plants that did not contain tannins were Agapanthus africanus, Agave americana, Clausena anisata, Dietes iridioides, Mesembruanthemum spp., Stangeria eriopus and Tulbaghia violacea.

  18. Oxidative bioelectrocatalysis: From natural metabolic pathways to synthetic metabolons and minimal enzyme cascades.

    Science.gov (United States)

    Minteer, Shelley D

    2016-05-01

    Anodic bioelectrodes for biofuel cells are more complex than cathodic bioelectrodes for biofuel cells, because laccase and bilirubin oxidase can individually catalyze four electron reduction of oxygen to water, whereas most anodic enzymes only do a single two electron oxidation of a complex fuel (i.e. glucose oxidase oxidizing glucose to gluconolactone while generating 2 electrons of the total 24 electrons), so enzyme cascades are typically needed for complete oxidation of the fuel. This review article will discuss the lessons learned from natural metabolic pathways about multi-step oxidation and how those lessons have been applied to minimal or artificial enzyme cascades. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  19. Natural variations in xenobiotic-metabolizing enzymes: developing tools for coral monitoring

    Science.gov (United States)

    Rougée, L. R. A.; Richmond, R. H.; Collier, A. C.

    2014-06-01

    The continued deterioration of coral reefs worldwide demonstrates the need to develop diagnostic tools for corals that go beyond general ecological monitoring and can identify specific stressors at sublethal levels. Cellular diagnostics present an approach to defining indicators (biomarkers) that have the potential to reflect the impact of stress at the cellular level, allowing for the detection of intracellular changes in corals prior to outright mortality. Detoxification enzymes, which may be readily induced or inhibited by environmental stressors, present such a set of indicators. However, in order to apply these diagnostic tools for the detection of stress, a detailed understanding of their normal, homeostatic levels within healthy corals must first be established. Herein, we present molecular and biochemical evidence for the expression and activity of major Phase I detoxification enzymes cytochrome P450 (CYP450), CYP2E1, and CYP450 reductase, as well as the Phase II enzymes UDP, glucuronosyltransferase (UGT), β-glucuronidase, glutathione- S-transferase (GST), and arylsulfatase C (ASC) in the coral Pocillopora damicornis. Additionally, we characterized enzyme expression and activity variations over a reproductive cycle within a coral's life history to determine natural endogenous changes devoid of stress exposure. Significant changes in enzyme activity over the coral's natural lunar reproductive cycle were observed for CYP2E1 and CYP450 reductase as well as UGT and GST, while β-glucuronidase and ASC did not fluctuate significantly. The data represent a baseline description of `health' for the expression and activity of these enzymes that can be used toward understanding the impact of environmental stressors on corals. Such knowledge can be applied to address causes of coral reef ecosystem decline and to monitor effectiveness of mitigation strategies. Achieving a better understanding of cause-and-effect relationships between putative stressors and biological

  20. Accessing non-natural reactivity by irradiating nicotinamide-dependent enzymes with light

    Science.gov (United States)

    Emmanuel, Megan A.; Greenberg, Norman R.; Oblinsky, Daniel G.; Hyster, Todd K.

    2016-12-01

    Enzymes are ideal for use in asymmetric catalysis by the chemical industry, because their chemical compositions can be tailored to a specific substrate and selectivity pattern while providing efficiencies and selectivities that surpass those of classical synthetic methods. However, enzymes are limited to reactions that are found in nature and, as such, facilitate fewer types of transformation than do other forms of catalysis. Thus, a longstanding challenge in the field of biologically mediated catalysis has been to develop enzymes with new catalytic functions. Here we describe a method for achieving catalytic promiscuity that uses the photoexcited state of nicotinamide co-factors (molecules that assist enzyme-mediated catalysis). Under irradiation with visible light, the nicotinamide-dependent enzyme known as ketoreductase can be transformed from a carbonyl reductase into an initiator of radical species and a chiral source of hydrogen atoms. We demonstrate this new reactivity through a highly enantioselective radical dehalogenation of lactones—a challenging transformation for small-molecule catalysts. Mechanistic experiments support the theory that a radical species acts as an intermediate in this reaction, with NADH and NADPH (the reduced forms of nicotinamide adenine nucleotide and nicotinamide adenine dinucleotide phosphate, respectively) serving as both a photoreductant and the source of hydrogen atoms. To our knowledge, this method represents the first example of photo-induced enzyme promiscuity, and highlights the potential for accessing new reactivity from existing enzymes simply by using the excited states of common biological co-factors. This represents a departure from existing light-driven biocatalytic techniques, which are typically explored in the context of co-factor regeneration.

  1. Flavin nucleotide metabolism in plants: monofunctional enzymes synthesize fad in plastids.

    Science.gov (United States)

    Sandoval, Francisco J; Zhang, Yi; Roje, Sanja

    2008-11-07

    FAD synthetases (EC 2.7.7.2) catalyze biosynthesis of FAD from FMN and ATP. Monofunctional FAD synthetases are known to exist in mammals and yeast; bifunctional enzymes also catalyzing phosphorylation of riboflavin to FMN are known to exist in bacteria. Previously known eukaryotic enzymes with FAD synthetase activity have no sequence similarity to prokaryotic enzymes with riboflavin kinase and FAD synthetase activities. Proteins homologous to bacterial bifunctional FAD synthetases, yet shorter and lacking amino acid motifs at the C terminus, were found by bioinformatic analyses in vascular plant genomes, suggesting that plants contain a type of FAD synthetase previously known to exist only in prokaryotes. The Arabidopsis thaliana genome encodes two of such proteins. Both proteins, which we named AtRibF1 and AtRibF2, carry N-terminal extensions with characteristics of organellar targeting peptides. AtRibF1 and AtRibF2 cDNAs were cloned by reverse transcription-PCR. Only FAD synthetase activity was detected in the recombinant enzymes produced in Escherichia coli. FMN and ATP inhibited both enzymes. Kinetic parameters of AtRibF1 and AtRibF2 for the two substrates were similar. Confocal microscopy of protoplasts transformed with enhanced green fluorescence protein-fused proteins showed that AtRibF1 and AtRibF2 are targeted to plastids. In agreement with subcellular localization to plastids, Percoll-isolated chloroplasts from pea (Pisum sativum) synthesized FAD from imported riboflavin. Riboflavin kinase, FMN hydrolase, and FAD pyrophosphatase activities were detected in Percoll-isolated chloroplasts and mitochondria from pea. We propose from these new findings a model for subcellular distribution of enzymes that synthesize and hydrolyze flavin nucleotides in plants.

  2. Methods of natural gas liquefaction and natural gas liquefaction plants utilizing multiple and varying gas streams

    Energy Technology Data Exchange (ETDEWEB)

    Wilding, Bruce M; Turner, Terry D

    2014-12-02

    A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO.sub.2 from a liquid NG process stream and processing the CO.sub.2 to provide a CO.sub.2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.

  3. Analysis of some enzymes activities of hydrogen sulfide metabolism in plants.

    Science.gov (United States)

    Li, Zhong-Guang

    2015-01-01

    Hydrogen sulfide (H2S) which is considered as a novel gasotransmitter after reactive oxygen species and nitric oxide in plants has dual character, that is, toxicity that inhibits cytochrome oxidase at high concentration and as signal molecule which is involved in plant growth, development, and the acquisition of tolerance to adverse environments such as extreme temperature, drought, salt, and heavy metal stress at low concentration. Therefore, H2S homeostasis is very important in plant cells. The level of H2S in plant cells is regulated by its synthetic and degradative enzymes, L-/D-cysteine desulfhydrase (L-/D-DES), sulfite reductase (SiR), and cyanoalanine synthase (CAS), which are responsible for H2S synthesis, while cysteine synthase (CS) takes charge of the degradation of H2S, but its reverse reaction also can produce H2S. Here, after crude enzyme is extracted from plant tissues, the activities of L-/D-DES, SiR, CAS, and CS are measured by spectrophotometry, the aim is to further understand homeostasis of H2S in plant cells and its potential mechanisms.

  4. Linkages between land Cover, enzymes, and soil organic matter chemistry following encroachment of leguminous woody plant into grasslands

    Science.gov (United States)

    Filley, T. R.; Stott, D. E.; Boutton, T. W.; Creamer, C. A.; Olk, D.

    2009-12-01

    In the Rio Grande Plains of southern Texas, subtropical thorn woodlands dominated by the N-fixing tree Prosopis glandulosa have largely replaced native grasslands over the last 150 years as a result of fire suppression and over grazing. This land cover change has resulted in the increase of belowground stocks of C, N, and P, changes to the amount and chemical nature of soil-stabilized plant biopolymers, and the composition and activity of soil microbes. Given that extracellular enzymes produced by plants and microbes are the principal means by which complex compounds are degraded and the production of such enzymes is triggered or suppressed by changes in primary input and nutrient availability we sought to relate how these fundamental changes in this ecosystem are reflected in the activity of soil stabilized extracellular enzymes and soil organic matter (SOM) chemistry in this system. We focused upon a successional chronosequence from C4-dominant grassland to woody patches of up to 86 yrs age since mesquite establishment. We related the molecular composition and concentration of hydrolysable amino acids and amino sugars, as well as CuO extractable lignin and substituted fatty acid to the potential activities of five extracellular enzymes (arylamidase, acid phosphatase, β-glucosidase, β-glucosaminidase (NAGase, polyphenoloxidase (PPO)) and a general marker for hydrolytic activity, fluorescein diacetate (FDA). Each of these enzymes, with the exception of PPO, showed higher potential activity in soils from woody clusters than grasslands and had activities generally well correlated to carbon content. PPO, often defined as a proxy for microbial lignin decay activity, showed no statistical difference between grassland and forest sites and no significant relationship to soil C content. Yields of total amino acids and amino sugars all show increases in content with cluster age when normalized to soil mass, as did the enzyme activities targeted to their decomposition, but

  5. Incorporating Peatland Plant Communities into the Enzymic 'Latch' Hypothesis: Can Vegetation Influence Carbon Storage Mechanisms?

    Science.gov (United States)

    Romanowicz, K. J.; Daniels, A. L.; Potvin, L. R.; Kane, E. S.; Kolka, R. K.; Chimner, R. A.; Lilleskov, E. A.

    2012-12-01

    High water table conditions in peatland ecosystems are known to favor plant production over decomposition and carbon is stored. Dominant plant communities change in response to water table but little is know of how these changes affect belowground carbon storage. One hypothesis known as the enzymic 'latch' proposed by Freeman et al. suggests that oxygen limitations due to high water table conditions inhibit microorganisms from synthesizing specific extracellular enzymes essential for carbon and nutrient mineralization, allowing carbon to be stored as decomposition is reduced. Yet, this hypothesis excludes plant community interactions on carbon storage. We hypothesize that the dominant vascular plant communities, sedges and ericaceous shrubs, will have inherently different effects on peatland carbon storage, especially in response to declines in water table. Sedges greatly increase in abundance following water table decline and create extensive carbon oxidation and mineralization hotspots through the production of deep roots with aerenchyma (air channels in roots). Increased oxidation may enhance aerobic microbial activity including increased enzyme activity, leading to peat subsidence and carbon loss. In contrast, ericaceous shrubs utilize enzymatically active ericoid mycorrhizal fungi that suppress free-living heterotrophs, promoting decreased carbon mineralization by mediating changes in rhizosphere microbial communities and enzyme activity regardless of water table declines. Beginning May 2010, bog monoliths were harvested, housed in mesocosm chambers, and manipulated into three vegetation treatments: unmanipulated (+sedge, +Ericaceae), sedge (+sedge, -Ericaceae), and Ericaceae (-sedge, +Ericaceae). Following vegetation manipulations, two distinct water table manipulations targeting water table seasonal profiles were implemented: (low intra-seasonal variability, higher mean water table; high intra-seasonal variability, lower mean water table). In 2012, peat

  6. Regulation of sucrose metabolism in higher plants: localization and regulation of activity of key enzymes

    Science.gov (United States)

    Winter, H.; Huber, S. C.; Brown, C. S. (Principal Investigator)

    2000-01-01

    Sucrose (Suc) plays a central role in plant growth and development. It is a major end product of photosynthesis and functions as a primary transport sugar and in some cases as a direct or indirect regulator of gene expression. Research during the last 2 decades has identified the pathways involved and which enzymes contribute to the control of flux. Availability of metabolites for Suc synthesis and 'demand' for products of sucrose degradation are important factors, but this review specifically focuses on the biosynthetic enzyme sucrose-phosphate synthase (SPS), and the degradative enzymes, sucrose synthase (SuSy), and the invertases. Recent progress has included the cloning of genes encoding these enzymes and the elucidation of posttranslational regulatory mechanisms. Protein phosphorylation is emerging as an important mechanism controlling SPS activity in response to various environmental and endogenous signals. In terms of Suc degradation, invertase-catalyzed hydrolysis generally has been associated with cell expansion, whereas SuSy-catalyzed metabolism has been linked with biosynthetic processes (e.g., cell wall or storage products). Recent results indicate that SuSy may be localized in multiple cellular compartments: (1) as a soluble enzyme in the cytosol (as traditionally assumed); (2) associated with the plasma membrane; and (3) associated with the actin cytoskeleton. Phosphorylation of SuSy has been shown to occur and may be one of the factors controlling localization of the enzyme. The purpose of this review is to summarize some of the recent developments relating to regulation of activity and localization of key enzymes involved in sucrose metabolism in plants.

  7. Determination of fluorine contents in plant samples by means of facilitated extraction with enzyme.

    Science.gov (United States)

    Lee, Junseok; An, Jinsung; Yoon, Hye-On

    2015-01-01

    In this study, facilitated extraction with enzyme was employed for the first time to extract fluorine (F) from plants. Feasibility of the proposed method for F analysis was assessed by comparing with the alkali fusion-ion selective electrode (ISE) method. In the extraction procedure, 30 mg of a protease and 0.1 g of a plant sample were added in 10 mL of deionized water. In the absence of sonication, the solution was mechanically shaken for 10 s. A variety of parameters (i.e., the amounts of enzymes used, physical treatment conditions applied, extraction time, temperature, and pH) were optimized to enhance the extraction efficiency of the proposed method. The suitability of the proposed method for various plant samples (i.e., grass, perilla, peanut, hot pepper, and eggplant) was also evaluated. The proposed method involves decreased operation time, simplified extraction procedures, and minimal consumption of hazardous reagents and solvents in comparison with other existing methods. Experimental results demonstrated that facilitated extraction with enzyme is appropriate for the rapid determination of F content in plant samples.

  8. Effects of poultry litter biochar on soil enzyme activities and tomato, pepper and lettuce plants growth

    Directory of Open Access Journals (Sweden)

    Muhittin Onur Akça

    2015-07-01

    Full Text Available Biochar application to soils is being considered as a means to sequester carbon (C while concurrently improving soil functions. A greenhouse experiment was carried out to determine the effects of biochar from the pyrolysis poultry litter (PL on the soil enzyme activities, organic matter content and growth of tomato, pepper and lettuce plants. In the experiment, the combination of 15.15.15 composite fertilizer with 0, 200, 400 and 600kg/da doses of PL biochar were applied into the clay loam soil. Compared to the control and chemical fertilizer alone, the soil organic matter was significantly increased after biochar amendments. β-glucosidase, alkaline phosphatase, urease and arylsulphatase enzyme activities in soils were increased by the biochar applications significantly (P<0.05. Plant fresh and dry weight of tomato, pepper and lettuce plants were higher in 4kg/ha PL biochar treatment than in the other treatments. The results showed that PL biochar amendment to soils in the agricultural use increased yield of plants and enzyme activities with increasing soil organic matter content as well as improving soil properties.

  9. Nature Inspired Solutions for Polymers: Will Cutinase Enzymes Make Polyesters and Polyamides Greener?

    Directory of Open Access Journals (Sweden)

    Valerio Ferrario

    2016-12-01

    Full Text Available The polymer and plastic sectors are under the urge of mitigating their environmental impact. The need for novel and more benign catalysts for polyester synthesis or targeted functionalization led, in recent years, to an increasing interest towards cutinases due to their natural ability to hydrolyze ester bonds in cutin, a natural polymer. In this review, the most recent advances in the synthesis and hydrolysis of various classes of polyesters and polyamides are discussed with a critical focus on the actual perspectives of applying enzymatic technologies for practical industrial purposes. More specifically, cutinase enzymes are compared to lipases and, in particular, to lipase B from Candida antarctica, the biocatalyst most widely employed in polymer chemistry so far. Computational and bioinformatics studies suggest that the natural role of cutinases in attacking natural polymers confer some essential features for processing also synthetic polyesters and polyamides.

  10. Cameroonian medicinal plants: Pharmacology and derived natural products

    Directory of Open Access Journals (Sweden)

    Thomas Efferth

    2010-10-01

    Full Text Available Many developing countries including Cameroon have mortality patterns that reflect high levels of infectious diseases and the risk of death during pregnancy and childbirth, in addition to cancers, cardiovascular diseases and chronic respiratory diseases that account for most deaths in the developed world. Several medicinal plants are used traditionally for their treatment. In this review, plants used in Cameroonian traditional medicine with evidence for the activities of their crude extracts and/or derived products have been discussed. A considerable number of plant extracts and isolated compounds possess significant antimicrobial, antiparasitic including anti-malarial, anti-proliferative, anti-inflammatory, anti-diabetes, and antioxidant effects. Most of the biologically active compounds belong to terpenoids, phenolics and alkaloids. Terpenoids from Cameroonian plants showed best activities as anti-parasitic, but rather poor antimicrobial effects. The best antimicrobial, anti-proliferative and antioxidant compounds were phenolics. In conclusion, many medicinal plants traditionally used in Cameroon to treat various ailments displayed good activities in vitro. This explains the endeavor of Cameroonian research institutes in drug discovery from indigenous medicinal plants. However, much work is still to be done to standardize methodologies and to study the mechanisms of action of isolated natural products.

  11. Reduced Dental Plaque Formation in Dogs Drinking a Solution Containing Natural Antimicrobial Herbal Enzymes and Organic Matcha Green Tea

    National Research Council Canada - National Science Library

    Lindinger, Michael I

    2016-01-01

    ...) reduced the rate of plaque formation on teeth of dogs consuming the OCP (antimicrobial plant-derived enzymes, organic matcha green tea, cultured dextrose, sodium bicarbonate, and ascorbic acid...

  12. Plant Cell Protolytic Enzymes Activity under Exposure to Lectins of Endophytic and Epiphytic Azospirillum Strains

    Directory of Open Access Journals (Sweden)

    S.A. Alen’kina

    2016-05-01

    Full Text Available We studied the ability of lectins isolated from the surface of the two strains of nitrogen-fixing soil bacteria of the genus Azospirillum, A. brasilense Sp7 (epiphytic and A. brasilense Sp245 (endophytic, to show have a regulating effect on the activity of pectinolytic enzymes in the roots of wheat seedlings. Research results showed that the lectins under study can cause the induction of the activity of polygalacturonase, pectinesterase, pectatlyase from the plant cell wall, thereby ensuring the bacteria penetration in the plant tissues, as well as the induction of plants responses which, being combined with growth-stimulating effect of bacteria, contributes to the formation of plants stability and productivity.

  13. Natural radioactivity assessment of a phosphate fertilizer plant area

    Directory of Open Access Journals (Sweden)

    S.K. Sahu

    2014-01-01

    Full Text Available Rock phosphate ore processing and disposal of phosphogypsum contribute to enhanced levels of natural radionuclides in the environment. The concentration of naturally occurring radionuclides in soil, rock phosphate and phosphogypsum samples collected around a phosphate fertilizer plant were determined. Also the external background gamma levels were surveyed.238U, 232Th, 226Ra and 40K activities in soil samples were 21–674 Bq/kg, 11–44 Bq/kg, 22–683 Bq/kg and 51–295 Bq/kg respectively. The external background gamma radiation levels in the plant premises were ranging from 48 to 133 nGy/h.

  14. The Complexity of Bioactive Natural Products in Plants

    DEFF Research Database (Denmark)

    Frisch, Tina

    Plants produce a diverse range of bioactive natural products promoting their fitness. These specialized metabolites may serve as chemical defence against herbivores and pathogens and may inhibit the growth and development of competing species. Hydroxynitrile glucosides and glucosinolates are two...... classes of defence compounds, which have diverging properties, but also share common biosynthetic features. Hydroxynitrile glucosides are produced in species across the plant kingdom, whereas glucosinolates are found almost exclusively within the Brassicales, which generally does not contain...... these two plant species interesting gateways for addressing these questions of evolution. The presented research demonstrates that the biosynthetic pathway for the hydroxynitrile glucoside alliarinoside in A. petiolata does not follow the general scheme for hydroxynitrile glucoside biosynthesis in other...

  15. Effect of rhizosphere enzymes on phytoremediation in PAH-contaminated soil using five plant species.

    Directory of Open Access Journals (Sweden)

    Rui Liu

    Full Text Available A pot experiment was performed to study the effectiveness of remediation using different plant species and the enzyme response involved in remediating PAH-contaminated soil. The study indicated that species Echinacea purpurea, Festuca arundinacea Schred, Fire Phoenix (a combined F. arundinacea, and Medicago sativa L. possess the potential for remediation in PAH-contaminated soils. The study also determined that enzymatic reactions of polyphenol oxidase (except Fire Phoenix, dehydrogenase (except Fire Phoenix, and urease (except Medicago sativa L. were more prominent over cultivation periods of 60d and 120d than 150d. Urease activity of the tested species exhibited prominently linear negative correlations with alkali-hydrolyzable nitrogen content after the tested plants were cultivated for 150d (R2 = 0.9592. The experiment also indicated that alkaline phosphatase activity in four of the five tested species (Echinacea purpurea, Callistephus chinensis, Festuca arundinacea Schred and Fire Phoenix was inhibited during the cultivation process (at 60d and 120d. At the same time, the study determined that the linear relationship between alkaline phosphatase activity and effective phosphorus content in plant rhizosphere soil exhibited a negative correlation after a growing period of 120d (R2 = 0.665. Phytoremediation of organic contaminants in the soil was closely related to specific characteristics of particular plant species, and the catalyzed reactions were the result of the action of multiple enzymes in the plant rhizosphere soil.

  16. Assessment of the effect of silicon on antioxidant enzymes in cotton plants by multivariate analysis.

    Science.gov (United States)

    Alberto Moldes, Carlos; Fontão de Lima Filho, Oscar; Manuel Camiña, José; Gabriela Kiriachek, Soraya; Lia Molas, María; Mui Tsai, Siu

    2013-11-27

    Silicon has been extensively researched in relation to the response of plants to biotic and abiotic stress, as an element triggering defense mechanisms which activate the antioxidant system. Furthermore, in some species, adding silicon to unstressed plants modifies the activity of certain antioxidant enzymes participating in detoxifying processes. Thus, in this study, we analyzed the activity of antioxidant enzymes in leaves and roots of unstressed cotton plants fertilized with silicon (Si). Cotton plants were grown in hydroponic culture and added with increasing doses of potassium silicate; then, the enzymatic activity of catalase (CAT), guaiacol peroxidase (GPOX), ascorbate peroxidase (APX), and lipid peroxidation were determined. Using multivariate analysis, we found that silicon altered the activity of GPOX, APX, and CAT in roots and leaves of unstressed cotton plants, whereas lipid peroxidation was not affected. The analysis of these four variables in concert showed a clear differentiation among Si treatments. We observed that enzymatic activities in leaves and roots changed as silicon concentration increased, to stabilize at 100 and 200 mg Si L(-1) treatments in leaves and roots, respectively. Those alterations would allow a new biochemical status that could be partially responsible for the beneficial effects of silicon. This study might contribute to adjust the silicon application doses for optimal fertilization, preventing potential toxic effects and unnecessary cost.

  17. Effect of Rhizosphere Enzymes on Phytoremediation in PAH-Contaminated Soil Using Five Plant Species

    Science.gov (United States)

    Liu, Rui; Dai, Yuanyuan; Sun, Libo

    2015-01-01

    A pot experiment was performed to study the effectiveness of remediation using different plant species and the enzyme response involved in remediating PAH-contaminated soil. The study indicated that species Echinacea purpurea, Festuca arundinacea Schred, Fire Phoenix (a combined F. arundinacea), and Medicago sativa L. possess the potential for remediation in PAH-contaminated soils. The study also determined that enzymatic reactions of polyphenol oxidase (except Fire Phoenix), dehydrogenase (except Fire Phoenix), and urease (except Medicago sativa L.) were more prominent over cultivation periods of 60d and 120d than 150d. Urease activity of the tested species exhibited prominently linear negative correlations with alkali-hydrolyzable nitrogen content after the tested plants were cultivated for 150d (R2 = 0.9592). The experiment also indicated that alkaline phosphatase activity in four of the five tested species (Echinacea purpurea, Callistephus chinensis, Festuca arundinacea Schred and Fire Phoenix) was inhibited during the cultivation process (at 60d and 120d). At the same time, the study determined that the linear relationship between alkaline phosphatase activity and effective phosphorus content in plant rhizosphere soil exhibited a negative correlation after a growing period of 120d (R2 = 0.665). Phytoremediation of organic contaminants in the soil was closely related to specific characteristics of particular plant species, and the catalyzed reactions were the result of the action of multiple enzymes in the plant rhizosphere soil. PMID:25822167

  18. [Autosegregation of enzyme loci in agamospermous progenies of triploid plants of sugar beet (Beta vulgaris L.)].

    Science.gov (United States)

    Levites, E V; Kirikovich, S S

    2011-07-01

    The ratios of the phenotypic classes of glucosephosphate isomerase (GP12) and malate dehydrogenase (MDH1 and MDH2) were studied in agamospermous progenies of triploid sugar beet plants. The ratio of the phenotypic classes of these enzymes corresponds to the calculations based on the assumption of polyteny of chromosomes carrying alleles of the enzyme loci accompanied by the loss of extra copies of the alleles in the first division of a cell entering embryogenesis. An increase in the gene dosage due to polyteny leads to the appearance in the progeny with a definite frequency of alleles that were absent in the original parental plant. The notions of meiotic autosegregation and mitotic autosegregation characteristic of meiotic and mitotic agamospermy are introduced, as well as the term locus polygenotype characterizing not only the allelic composition and the number of chromosomes, but also the number of chromatids carrying alleles of the marker locus in the cell before its entry into embryogenesis.

  19. Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Rogowska-Wrzesinska, Adelina; Hoffmann, Daniel;

    2014-01-01

    The mutualism between leaf-cutting ants and their fungal symbionts revolves around processing and inoculation of fresh leaf pulp in underground fungus gardens, mediated by ant fecal fluid deposited on the newly added plant substrate. As herbivorous feeding often implies that growth is nitrogen li...... fungi, consistent with previous indications of convergent evolution of decomposition enzymes in attine ant fungal symbionts and phytopathogenic fungi.The ISME Journal advance online publication, 9 January 2014; doi:10.1038/ismej.2013.231....

  20. Cloning of Glycerophosphocholine Acyltransferase (GPCAT) from Fungi and Plants: A NOVEL ENZYME IN PHOSPHATIDYLCHOLINE SYNTHESIS.

    Science.gov (United States)

    Głąb, Bartosz; Beganovic, Mirela; Anaokar, Sanket; Hao, Meng-Shu; Rasmusson, Allan G; Patton-Vogt, Jana; Banaś, Antoni; Stymne, Sten; Lager, Ida

    2016-11-25

    Glycero-3-phosphocholine (GPC), the product of the complete deacylation of phosphatidylcholine (PC), was long thought to not be a substrate for reacylation. However, it was recently shown that cell-free extracts from yeast and plants could acylate GPC with acyl groups from acyl-CoA. By screening enzyme activities of extracts derived from a yeast knock-out collection, we were able to identify and clone the yeast gene (GPC1) encoding the enzyme, named glycerophosphocholine acyltransferase (GPCAT). By homology search, we also identified and cloned GPCAT genes from three plant species. All enzymes utilize acyl-CoA to acylate GPC, forming lyso-PC, and they show broad acyl specificities in both yeast and plants. In addition to acyl-CoA, GPCAT efficiently utilizes LPC and lysophosphatidylethanolamine as acyl donors in the acylation of GPC. GPCAT homologues were found in the major eukaryotic organism groups but not in prokaryotes or chordates. The enzyme forms its own protein family and does not contain any of the acyl binding or lipase motifs that are present in other studied acyltransferases and transacylases. In vivo labeling studies confirm a role for Gpc1p in PC biosynthesis in yeast. It is postulated that GPCATs contribute to the maintenance of PC homeostasis and also have specific functions in acyl editing of PC (e.g. in transferring acyl groups modified at the sn-2 position of PC to the sn-1 position of this molecule in plant cells). © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

    Science.gov (United States)

    Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

    2014-01-01

    The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems.

  2. Genome-level and biochemical diversity of the acyl-activating enzyme superfamily in plants.

    Science.gov (United States)

    Shockey, Jay; Browse, John

    2011-04-01

    In higher plants, the superfamily of carboxyl-CoA ligases and related proteins, collectively called acyl activating enzymes (AAEs), has evolved to provide enzymes for many pathways of primary and secondary metabolism and for the conjugation of hormones to amino acids. Across the superfamily there is only limited sequence similarity, but a series of highly conserved motifs, including the AMP-binding domain, make it easy to identify members. These conserved motifs are best understood in terms of the unique domain-rotation architecture that allows AAE enzymes to catalyze the two distinct steps of the CoA ligase reaction. Arabidopsis AAE sequences were used to identify the AAE gene families in the sequenced genomes of green algae, mosses, and trees; the size of the respective families increased with increasing degree of organismal cellular complexity, size, and generation time. Large-scale genome duplications and small-scale tandem gene duplications have contributed to AAE gene family complexity to differing extents in each of the multicellular species analyzed. Gene duplication and evolution of novel functions in Arabidopsis appears to have occurred rapidly, because acquisition of new substrate specificity is relatively easy in this class of proteins. Convergent evolution has also occurred between members of distantly related clades. These features of the AAE superfamily make it difficult to use homology searches and other genomics tools to predict enzyme function. The Plant Journal © 2011 Blackwell Publishing Ltd. No claim to original US government works.

  3. Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

    Directory of Open Access Journals (Sweden)

    Nilüfer Orhan

    2014-06-01

    Full Text Available Objective(s:Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus  communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum, are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2 on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml. Conclusion:Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes.

  4. Enzyme inhibitory and antioxidant activities of traditional medicinal plants: Potential application in the management of hyperglycemia

    Directory of Open Access Journals (Sweden)

    Gulati Vandana

    2012-06-01

    Full Text Available Abstract Background Traditional Indian and Australian medicinal plant extracts were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of hyperglycemia and type 2 diabetes. The antioxidant activities were also assessed. Methods The evaluation of enzyme inhibitory activity of seven Australian aboriginal medicinal plants and five Indian Ayurvedic plants was carried out against α-amylase and α-glucosidase. Antioxidant activity was determined by measuring (i the scavenging effect of plant extracts against 2, 2-diphenyl-1-picryl hydrazyl (DPPH and 2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS and (ii ferric reducing power. Total phenolic and total flavonoid contents were also determined. Results Of the twelve plant extracts evaluated, the highest inhibitory activity against both α-amylase and α-glucosidase enzymes was exerted by Santalum spicatum and Pterocarpus marsupium with IC50 values of 5.43 μg/ml and 0.9 μg/ml, respectively, and 5.16 μg/ml and 1.06 μg/ml, respectively. However, the extracts of Acacia ligulata (IC50 = 1.01 μg/ml, Beyeria leshnaultii (0.39 μg/ml, Mucuna pruriens (0.8 μg/ml and Boerhaavia diffusa (1.72 μg/ml exhibited considerable activity against α-glucosidase enzyme only. The free radical scavenging activity was found to be prominent in extracts of Acacia kempeana, Acacia ligulata followed by Euphorbia drummondii against both DPPH and ABTS. The reducing power was more pronounced in Euphorbia drummondii and Pterocarpus marsupium extracts. The phenolic and flavonoid contents ranged from 0.42 to 30.27 μg/mg equivalent of gallic acid and 0.51 to 32.94 μg/mg equivalent of quercetin, respectively, in all plant extracts. Pearson’s correlation coefficient between total flavonoids and total phenolics was 0.796. Conclusion The results obtained in this study showed that most of the plant extracts

  5. Enzyme inhibitory and antioxidant activities of traditional medicinal plants: Potential application in the management of hyperglycemia

    Science.gov (United States)

    2012-01-01

    Background Traditional Indian and Australian medicinal plant extracts were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of hyperglycemia and type 2 diabetes. The antioxidant activities were also assessed. Methods The evaluation of enzyme inhibitory activity of seven Australian aboriginal medicinal plants and five Indian Ayurvedic plants was carried out against α-amylase and α-glucosidase. Antioxidant activity was determined by measuring (i) the scavenging effect of plant extracts against 2, 2-diphenyl-1-picryl hydrazyl (DPPH) and 2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS) and (ii) ferric reducing power. Total phenolic and total flavonoid contents were also determined. Results Of the twelve plant extracts evaluated, the highest inhibitory activity against both α-amylase and α-glucosidase enzymes was exerted by Santalum spicatum and Pterocarpus marsupium with IC50 values of 5.43 μg/ml and 0.9 μg/ml, respectively, and 5.16 μg/ml and 1.06 μg/ml, respectively. However, the extracts of Acacia ligulata (IC50 = 1.01 μg/ml), Beyeria leshnaultii (0.39 μg/ml), Mucuna pruriens (0.8 μg/ml) and Boerhaavia diffusa (1.72 μg/ml) exhibited considerable activity against α-glucosidase enzyme only. The free radical scavenging activity was found to be prominent in extracts of Acacia kempeana, Acacia ligulata followed by Euphorbia drummondii against both DPPH and ABTS. The reducing power was more pronounced in Euphorbia drummondii and Pterocarpus marsupium extracts. The phenolic and flavonoid contents ranged from 0.42 to 30.27 μg/mg equivalent of gallic acid and 0.51 to 32.94 μg/mg equivalent of quercetin, respectively, in all plant extracts. Pearson’s correlation coefficient between total flavonoids and total phenolics was 0.796. Conclusion The results obtained in this study showed that most of the plant extracts have good potential

  6. Survival of Bemisia tabaci and activity of plant defense-related enzymes in genotypes of Capsicum annuum L.

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    Luis Latournerie-Moreno

    2015-03-01

    Full Text Available The whitefly Bemisia tabaci (Gennadius, 1889 is a major plant pest of horticultural crops from the families Solanaceae, Fabaceae and Cucurbitaceae in Neotropical areas. The exploration of host plant resistance and their biochemical mechanisms offers an excellent alternative to better understand factors affecting the interaction between phytophagous insect and host plant. We evaluated the survival of B. tabaci in landrace genotypes of Capsicum annuum L., and the activity of plant defense-related enzymes (chitinase, polyphenoloxidase, and peroxidase. The landrace genotypes Amaxito, Tabaquero, and Simojovel showed resistance to B. tabaci, as we observed more than 50% nymphal mortality, while in the commercial susceptible genotype Jalapeño mortality of B. tabaci nymphs was not higher than 20%. The activities of plant defense-related enzymes were significantly different among pepper genotypes (P < 0.05. Basal activities of chitinase, polyphenoloxidase and peroxidase were significantly lower or equal in landrace genotypes than that of the commercial genotype Jalapeño. The activity of plant enzymes was differential among pepper genotypes (P < 0.05. For example, the activity of chitinase enzyme generally was higher in non-infested plants with B. tabaci than those infested. Instead polyphenoloxidase ('Amaxito' and 'Simojovel' and peroxidase enzymes activities ('Tabaquero' increased in infested plants (P < 0.05. We conclude that basal activities of plant defense-related enzymes could be act through other mechanism plant induction, since plant defense-related enzymes showed a different induction response to B. tabaci. We underlined the role of polyphenoloxidase as plant defense in the pepper genotype Simojovel related to B. tabaci.

  7. Natural enemies drive geographic variation in plant defenses.

    Science.gov (United States)

    Züst, Tobias; Heichinger, Christian; Grossniklaus, Ueli; Harrington, Richard; Kliebenstein, Daniel J; Turnbull, Lindsay A

    2012-10-01

    Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources of Arabidopsis thaliana, coupled with 39 years of field data on aphid abundance, to (i) demonstrate that geographic patterns in a polymorphic defense locus (GS-ELONG) are strongly correlated with changes in the relative abundance of two specialist aphids; and (ii) demonstrate differential selection by the two aphids on GS-ELONG, using a multigeneration selection experiment. We thereby show a causal link between variation in abundance of the two specialist aphids and the geographic pattern at GS-ELONG, which highlights the potency of natural enemies as selective forces.

  8. The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

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    Gigot, C.

    2010-01-01

    Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

  9. Development of a functional bioassay for arylsulfatase B using the natural substrates of the enzyme.

    Science.gov (United States)

    Pungor, Erno; Hague, Charles M; Chen, Ginger; Lemontt, Jeffrey F; Dvorak-Ewell, Melita; Prince, William S

    2009-12-15

    A functional bioassay has been developed for measuring the intracellular activity of recombinant human arylsulfatase B (rhASB) on its natural glycosaminoglycan (GAG) substrates, dermatan sulfate (DS), and chondroitin sulfate (CS) when the enzyme is taken up into cultured ASB-deficient human fibroblasts (GM00519). The enzyme ASB is a lysosomal exohydrolase, cleaving sulfate from the N-acetylgalactosamine-4-sulfate (GalNAc-4S) residue at the nonreducing terminal of GAG structures. ASB-deficient cells accumulate DS and CS, which may be partially hydrolyzed by other lysosomal hydrolases, with the reactions stopping if a GalNAc-4S residue is reached on the nonreducing end of the oligosaccharide. When rhASB is added to the culture medium, the enzyme is taken up and translocates to the lysosomes and the intracellular DS and CS are depleted, demonstrating that the uptake of rhASB is able to restore lysosomal function in an in vitro cell-based assay. The accumulation and depletion of DS and CS are measured by digesting the residual intracellular DS and CS content with chondroitin ABC lyase and monitoring a characteristic disaccharide digestion product by laser-induced fluorescence-capillary zone electrophoresis (LIF-CZE). In the proposed assay format, GM00519 cells are cultured 5 weeks postconfluence to accumulate DS/CS, followed by incubation with rhASB (1-20 pM) for 5 days, and the CS/DS depletion profiles are compared between samples. The assay measures depletion of DS/CS independently of their molecular size or processing state; in this approach, all DS- and CS-like substances accumulating in the absence of ASB activity are considered to be natural substrates of the enzyme.

  10. Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

    Science.gov (United States)

    Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

    2012-01-01

    A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

  11. Angiotensin-converting enzyme inhibition studies by natural leech inhibitors by capillary electrophoresis and competition assay.

    Science.gov (United States)

    Deloffre, Laurence; Sautiere, Pierre-Eric; Huybrechts, Roger; Hens, Korneel; Vieau, Didier; Salzet, Michel

    2004-06-01

    A protocol to follow the processing of angiotensin I into angiotensin II by rabbit angiotensin-converting enzyme (ACE) and its inhibition by a novel natural antagonist, the leech osmoregulator factor (LORF) using capillary zonal electrophoresis is described. The experiment was carried out using the Beckman PACE system and steps were taken to determine (a) the migration profiles of angiotensin and its yielded peptides, (b) the minimal amount of angiotensin II detected, (c) the use of different electrolytes and (d) the concentration of inhibitor. We demonstrated that LORF (IPEPYVWD), a neuropeptide previously found in leech brain, is able to inhibit rabbit ACE with an IC(50) of 19.8 micro m. Interestingly, its cleavage product, IPEP exhibits an IC(50) of 11.5 micro m. A competition assay using p-benzoylglycylglycylglycine and insect ACE established that LORF and IPEP fragments are natural inhibitors for invertebrate ACE. Fifty-four percent of insect ACE activity is inhibited with 50 micro m IPEP and 35% inhibition with LORF (25 mm). Extending the peptide at both N- and C-terminus (GWEIPEPYVWDES) and the cleavage of IPEP in IP abolished the inhibitory activity of both peptides. Immunocytochemical data obtained with antisera raised against LORF and leech ACE showed a colocalization between the enzyme and its inhibitor in the same neurons. These results showed that capillary zonal electrophoresis is a useful technique for following enzymatic processes with small amounts of products and constitutes the first evidence of a natural ACE inhibitor in invertebrates.

  12. Plant Flavonoids as Angiotensin Converting Enzyme Inhibitors in Regulation of Hypertension

    Directory of Open Access Journals (Sweden)

    H.P. Vasantha Rupasinghe

    2011-05-01

    Full Text Available Background: Angiotensin converting enzyme (ACE is a key component in the renin angiotensin aldosterone system (RAAS which regulates blood pressure. As the over expression of RAAS is associated with vascular hypertension, ACE inhibition has become a major target control for hypertension. The research on potential ACE inhibitors is expanding broadly and most are focused on natural product derivatives such as peptides, polyphenolics, and terpenes. Plant polyphenolics are antioxidant molecules with various beneficial pharmacological properties. The current study is focused on investigating and reviewing the ACE inhibitory property of fruit flavonoids. An apple skin extract (ASE rich in flavonoids, the major constituents of the extract and their selected metabolites were assessed for the ACE inhibitory property in vitro. It is important to investigate the metabolites along with the flavonoids as they are the constituents active inside the human body.Objective: To investigate whether flavonoids, flavonoid rich apple extracts and their metabolites could inhibit ACE in vitro.Method: The samples were incubated with sodium borate buffer (30 μL, pH 8.3, 150 μL of substrate (Hip-His-Liu and ACE (30 μL at 37 oC for 1 h. The reaction was stopped by addition of 150 μL of 0.3M NaOH. The enzyme cleaved substrate was detected by making a fluorimetricadduct by adding 100 μL of o-phthaladehyde for 10 min at room temperature. Reaction wasstopped by adding 50 μL of 3M HCl. Fluorescence was measured by using a FluoStar Optimaplate reader at excitation of 350 nm and emission of 500 nm.Results: The extract and the compounds showed a concentration dependant enzyme inhibition.Increasing concentrations from 0.001 ppm to 100 ppm of ASE showed an increment of 29% to64% ACE inhibition. The IC50 (concentration of test compound which gives 50% enzymeinhibition values of ASE, quercetin, quercetin-3-glucoside, quercetin-3-galactoside, cyanidin-3-galactoside were 49

  13. Interactions between plant proteins/enzymes and other food components, and their effects on food quality.

    Science.gov (United States)

    Lv, Chenyan; Zhao, Guanghua; Ning, Yong

    2017-05-24

    Plant proteins are the main sources of dietary protein for humans, especially for vegetarians. There are a variety of components with different properties coexisting in foodstuffs, so the interactions between these components are inevitable to occur, thereby affecting food quality. Among these interactions, the interplay between plant proteins/enzymes from fruits and vegetables, cereals, and legumes and other molecules plays an important role in food quality, which recently has gained a particular scientific interest. Such interactions not only affect the appearances of fruits and vegetables and the functionality of cereal products but also the nutritive properties of plant foods. Non-covalent forces, such as hydrogen bond, hydrophobic interaction, electrostatic interaction, and van der Waals forces, are mainly responsible for these interactions. Future outlook is highlighted with aim to suggest a research line to be followed in further studies.

  14. Genetic evidence for natural product-mediated plant-plant allelopathy in rice (Oryza sativa).

    Science.gov (United States)

    Xu, Meimei; Galhano, Rita; Wiemann, Philipp; Bueno, Emilio; Tiernan, Mollie; Wu, William; Chung, Ill-Min; Gershenzon, Jonathan; Tudzynski, Bettina; Sesma, Ane; Peters, Reuben J

    2012-02-01

    • There is controversy as to whether specific natural products play a role in directly mediating antagonistic plant-plant interactions - that is, allelopathy. If proved to exist, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (Oryza sativa). • However, while substantiated by the presence of phytotoxic compounds at potentially relevant concentrations, demonstrating a direct role for specific natural products in allelopathy has been difficult because of the chemical complexity of root and plant litter exudates. This complexity can be bypassed via selective genetic manipulation to ablate production of putative allelopathic compounds, but such an approach previously has not been applied. • The rice diterpenoid momilactones provide an example of natural products for which correlative biochemical evidence has been obtained for a role in allelopathy. Here, we apply reverse genetics, using knock-outs of the relevant diterpene synthases (copalyl diphosphate synthase 4 (OsCPS4) and kaurene synthase-like 4 (OsKSL4)), to demonstrate that rice momilactones are involved in allelopathy, including suppressing growth of the widespread rice paddy weed, barnyard grass (Echinochloa crus-galli). • Thus, our results not only provide novel genetic evidence for natural product-mediated allelopathy, but also furnish a molecular target for breeding and metabolic engineering of this important crop plant. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  15. Subcellular site and nature of intracellular cadmium in plants

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, George J.

    1979-01-01

    The mechanisms underlying heavy metal accumulation, toxicity and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent of, subcellular site of and nature of intracellularly accumulated cadmium in higher plants. Whole plants supplied /sup 109/CdCl/sub 2/ or /sup 112/CdSO/sub 4/ accumulated Cd into roots and aerial tissues. Preparation of protoplasts from aerial tissue followed by subcellular fractionation of the protoplasts to obtain intact vacuoles, chloroplasts and cytosol revealed the presence of Cd in the cytosol but not in vacuoles or chloroplasts. Particulate materials containing other cell components were also labeled. Of the /sup 109/Cd supplied to plants, 2 to 10% was recovered in both cytosol preparations and in particulate materials. Cytosol contained proteinaceous--Cd complexes, free metal and low molecular weight Cd complexes. Labeling of protoplasts gave similar results. No evidence was obtained for the production of volatile Cd complexes in tobacco.

  16. Plant latex: A natural source of pharmaceuticals and pesticides

    Directory of Open Access Journals (Sweden)

    Ravi K Upadhyay

    2011-01-01

    Full Text Available In recent times use of plant natural products has increased tremendously, and there is a very high demand of herbal products for therapeutic, clinical, agricultural purposes. Plant latex is a rich source of pharmaceuticals, pesticides and immune allergens. It also contains important biomolecules such as glycosides, tannins, phytosterols, Flavonoids, acetogenins and saponins, which show diverse biolgical activities against bacteria, fungi, viruses, protozoans, nematodes, insects, and cancer and tumours. It is also used as disinfectant, anticoagulant, anti-inflammatory, antioxidant and antiproliferative agent that provides protection in wounds. It contains wide variety of industrially important metabolic substances which can be harvested, modified, quenched, and polymerized easily for making goods and materials by up-gradation of technology. No doubt it is a future raw material for many bioengineering and biotechnological industries.

  17. Glycosylation Helps Cellulase Enzymes Bind to Plant Cell Walls (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-06-01

    Computer simulations suggest a new strategy to design enhanced enzymes for biofuels production. Large-scale computer simulations predict that the addition of glycosylation on carbohydrate-binding modules can dramatically improve the binding affinity of these protein domains over amino acid mutations alone. These simulations suggest that glycosylation can be used as a protein engineering tool to enhance the activity of cellulase enzymes, which are a key component in the conversion of cellulose to soluble sugars in the production of biofuels. Glycosylation is the covalent attachment of carbohydrate molecules to protein side chains, and is present in many proteins across all kingdoms of life. Moreover, glycosylation is known to serve a wide variety of functions in biological recognition, cell signaling, and metabolism. Cellulase enzymes, which are responsible for deconstructing cellulose found in plant cell walls to glucose, contain glycosylation that when modified can affect enzymatic activity-often in an unpredictable manner. To gain insight into the role of glycosylation on cellulase activity, scientists at the National Renewable Energy Laboratory (NREL) used computer simulation to predict that adding glycosylation on the carbohydrate-binding module of a cellulase enzyme dramatically boosts the binding affinity to cellulose-more than standard protein engineering approaches in which amino acids are mutated. Because it is known that higher binding affinity in cellulases leads to higher activity, this work suggests a new route to designing enhanced enzymes for biofuels production. More generally, this work suggests that tuning glycosylation in cellulase enzymes is a key factor to consider when engineering biochemical conversion processes, and that more work is needed to understand how glycosylation affects cellulase activity at the molecular level.

  18. Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate.

    Science.gov (United States)

    Kooij, Pepijn W; Rogowska-Wrzesinska, Adelina; Hoffmann, Daniel; Roepstorff, Peter; Boomsma, Jacobus J; Schiøtt, Morten

    2014-05-01

    The mutualism between leaf-cutting ants and their fungal symbionts revolves around processing and inoculation of fresh leaf pulp in underground fungus gardens, mediated by ant fecal fluid deposited on the newly added plant substrate. As herbivorous feeding often implies that growth is nitrogen limited, we cloned and sequenced six fungal proteases found in the fecal fluid of the leaf-cutting ant Acromyrmex echinatior and identified them as two metalloendoproteases, two serine proteases and two aspartic proteases. The metalloendoproteases and serine proteases showed significant activity in fecal fluid at pH values of 5-7, but the aspartic proteases were inactive across a pH range of 3-10. Protease activity disappeared when the ants were kept on a sugar water diet without fungus. Relative to normal mycelium, both metalloendoproteases, both serine proteases and one aspartic protease were upregulated in the gongylidia, specialized hyphal tips whose only known function is to provide food to the ants. These combined results indicate that the enzymes are derived from the ingested fungal tissues. We infer that the five proteases are likely to accelerate protein extraction from plant cells in the leaf pulp that the ants add to the fungus garden, but regulatory functions such as activation of proenzymes are also possible, particularly for the aspartic proteases that were present but without showing activity. The proteases had high sequence similarities to proteolytic enzymes of phytopathogenic fungi, consistent with previous indications of convergent evolution of decomposition enzymes in attine ant fungal symbionts and phytopathogenic fungi.

  19. Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

    Directory of Open Access Journals (Sweden)

    Jan-Christoph Kehr

    2011-12-01

    Full Text Available Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS and polyketide synthase (PKS pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.

  20. Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes.

    Science.gov (United States)

    Kehr, Jan-Christoph; Gatte Picchi, Douglas; Dittmann, Elke

    2011-01-01

    Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.

  1. Kareel plant: A natural source of medicines and nutrients

    Directory of Open Access Journals (Sweden)

    Ravi K Upadhyay

    2011-01-01

    Full Text Available Capparis decidua or kareel is an indigenous medicinal plant of India having large biodiversity in different north-western states of India. The young flower bud and fruits are used to make pickles while caper berries are used as vegetable. Plant has its wider utility in traditional folk medicine and is used as ailments to relieve variety of pains or aches such as toothache, cough and asthma heal. Plant contains few important secondary metabolites such as quercetin which act as melanogenesis stimulator and also increase tyrosinase protein expression. Capparis sp. seeds contain lectin that exhibit potent anti HIV-1 reverse transcriptase inhibition activity and also inhibits proliferation of hepatoma HepG2 and breast cancer MCF-7 cells. It shows anti-rheumatic, anti-diabitic, anti-arthritis and anti-gout agent. C. decidua contains generous quantities of alkaloids, fatty acids, terpenes, vitamins, fibre and oils that show greater medicinal and nutritive value. It also contains saccharides, glycosides, flavonoids, volatile oils, sterols and steroids, which showed multiple pharmacological effects such as anti-inflammatory, odynolysis, anti-fungus, hepatoprotective effect, hypoglycemic activity, anti-oxidation, anti-hyperlipemia, anti-coagulated blood, smooth muscle stimulation, anti-stress reaction. Cadabicine an alkaloid that occurs in leaves shows anti-parasitic activity, while root bark and pulp are used to kill helminthes. Due to enzymatic inhibition plant extract shows the ability to control Leishmania major and L. infantum, L. donovani, L. braziliensis, Crithidia fasciculata and Herpetomonas muscarum infection. In the present review article both medicinal and nutraceutical properties of C decidua have been described in detail and special emphasis is given on its sustainable use of plant and its conservation in natural habitat.

  2. Computational analysis of the fructosyltransferase enzymes in plants, fungi and bacteria.

    Science.gov (United States)

    Alméciga-Díaz, Carlos J; Gutierrez, Angela M; Bahamon, Isabella; Rodríguez, Alexander; Rodríguez, Mauro A; Sánchez, Oscar F

    2011-09-15

    Fructosyltransferases (FTases) are enzymes produced by plants, fungi, and bacteria, which are responsible for the synthesis of fructooligosaccharides. In this study, we conducted a computational analysis of reported sequences for FTase from a diverse source of organisms, such as plants, fungi, and bacteria. Ninety-one proteins sequences were obtained; all belonging to the glycoside hydrolase 32 (GH32) and 68 (GH68) families. The sequences were grouped in seven clades, five for plants, one for fungi, and one for bacteria. Our findings suggest that FTases from fungi and bacteria likely evolved from dicotyledonous FTases. The analysis of catalytic domains A, D and E, which contain the amino acids involved in the catalytic binding site, allowed the identification of clade-specific conserved characteristics. The analysis of sequence motifs involved in donor/acceptor molecule affinity showed that additional sequences could be responsible for donor/acceptor molecule affinity. The correlation of this large set of FTases allowed to identify additional features that might be used for the identification and classification of new FTases, and to improve the understanding of these valuable enzymes.

  3. High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Lucena Severino A

    2011-11-01

    Full Text Available Abstract Background The description of new hydrolytic enzymes is an important step in the development of techniques which use lignocellulosic materials as a starting point for fuel production. Sugarcane bagasse, which is subjected to pre-treatment, hydrolysis and fermentation for the production of ethanol in several test refineries, is the most promising source of raw material for the production of second generation renewable fuels in Brazil. One problem when screening hydrolytic activities is that the activity against commercial substrates, such as carboxymethylcellulose, does not always correspond to the activity against the natural lignocellulosic material. Besides that, the macroscopic characteristics of the raw material, such as insolubility and heterogeneity, hinder its use for high throughput screenings. Results In this paper, we present the preparation of a colloidal suspension of particles obtained from sugarcane bagasse, with minimal chemical change in the lignocellulosic material, and demonstrate its use for high throughput assays of hydrolases using Brazilian termites as the screened organisms. Conclusions Important differences between the use of the natural substrate and commercial cellulase substrates, such as carboxymethylcellulose or crystalline cellulose, were observed. This suggests that wood feeding termites, in contrast to litter feeding termites, might not be the best source for enzymes that degrade sugarcane biomass.

  4. Catalase and ascorbate peroxidase-representative H2O2-detoxifying heme enzymes in plants.

    Science.gov (United States)

    Anjum, Naser A; Sharma, Pallavi; Gill, Sarvajeet S; Hasanuzzaman, Mirza; Khan, Ekhlaque A; Kachhap, Kiran; Mohamed, Amal A; Thangavel, Palaniswamy; Devi, Gurumayum Devmanjuri; Vasudhevan, Palanisamy; Sofo, Adriano; Khan, Nafees A; Misra, Amarendra Narayan; Lukatkin, Alexander S; Singh, Harminder Pal; Pereira, Eduarda; Tuteja, Narendra

    2016-10-01

    Plants have to counteract unavoidable stress-caused anomalies such as oxidative stress to sustain their lives and serve heterotrophic organisms including humans. Among major enzymatic antioxidants, catalase (CAT; EC 1.11.1.6) and ascorbate peroxidase (APX; EC 1.11.1.11) are representative heme enzymes meant for metabolizing stress-provoked reactive oxygen species (ROS; such as H2O2) and controlling their potential impacts on cellular metabolism and functions. CAT mainly occurs in peroxisomes and catalyzes the dismutation reaction without requiring any reductant; whereas, APX has a higher affinity for H2O2 and utilizes ascorbate (AsA) as specific electron donor for the reduction of H2O2 into H2O in organelles including chloroplasts, cytosol, mitochondria, and peroxisomes. Literature is extensive on the glutathione-associated H2O2-metabolizing systems in plants. However, discussion is meager or scattered in the literature available on the biochemical and genomic characterization as well as techniques for the assays of CAT and APX and their modulation in plants under abiotic stresses. This paper aims (a) to introduce oxidative stress-causative factors and highlights their relationship with abiotic stresses in plants; (b) to overview structure, occurrence, and significance of CAT and APX in plants;

  5. Interactions in Natural Colloid Systems "Biosolids" - Soil and Plant

    Science.gov (United States)

    Kalinichenko, Kira V.; Nikovskaya, Galina N.; Ulberg, Zoya R.

    2016-04-01

    The "biosolids" are complex biocolloid system arising in huge amounts (mln tons per year) from biological municipal wastewater treatment. These contain clusters of nanoparticles of heavy metal compounds (in slightly soluble or unsoluble forms, such as phosphates, sulphates, carbonates, hydroxides, and etc.), cells, humic substances and so on, involved in exopolysaccharides (EPS) net matrix. One may consider that biosolids are the natural nanocomposite. Due to the presence of nitrogen, phosphorus, potassium and other macro- and microelements (heavy metals), vitamins, aminoacids, etc., the biosolids are a depot of bioelements for plant nutrition. Thus, it is generally recognized that most rationally to utilize them for land application. For this purpose the biocolloid process was developed in biosolids system by initiation of microbial vital ability followed by the synthesis of EPS, propagation of ecologically important microorganisms, loosening of the structure and weakening of the coagulation contacts between biosolids colloids, but the structure integrity maintaining [1,2]. It was demonstrated that the applying of biosolids with metabolizing microorganisms to soil provided the improving soil structure, namely the increasing of waterstable aggregates content (70% vs. 20%). It occurs due to flocculation ability of biosolids EPS. The experimental modelling of mutual interactions in systems of soils - biosolids (with metabolizing microorganisms) were realized and their colloid and chemical mechanisms were formulated [3]. As it is known, the most harmonious plant growth comes at a prolonged entering of nutrients under the action of plant roots exudates which include pool of organic acids and polysaccharides [4]. Special investigations showed that under the influence of exudates excreted by growing plants, the biosolids microelements can release gradually from immobilized state into environment and are able to absorb by plants. Thus, the biosolids can serve as an active

  6. Affinity Crystallography: A New Approach to Extracting High-Affinity Enzyme Inhibitors from Natural Extracts.

    Science.gov (United States)

    Aguda, Adeleke H; Lavallee, Vincent; Cheng, Ping; Bott, Tina M; Meimetis, Labros G; Law, Simon; Nguyen, Nham T; Williams, David E; Kaleta, Jadwiga; Villanueva, Ivan; Davies, Julian; Andersen, Raymond J; Brayer, Gary D; Brömme, Dieter

    2016-08-26

    Natural products are an important source of novel drug scaffolds. The highly variable and unpredictable timelines associated with isolating novel compounds and elucidating their structures have led to the demise of exploring natural product extract libraries in drug discovery programs. Here we introduce affinity crystallography as a new methodology that significantly shortens the time of the hit to active structure cycle in bioactive natural product discovery research. This affinity crystallography approach is illustrated by using semipure fractions of an actinomycetes culture extract to isolate and identify a cathepsin K inhibitor and to compare the outcome with the traditional assay-guided purification/structural analysis approach. The traditional approach resulted in the identification of the known inhibitor antipain (1) and its new but lower potency dehydration product 2, while the affinity crystallography approach led to the identification of a new high-affinity inhibitor named lichostatinal (3). The structure and potency of lichostatinal (3) was verified by total synthesis and kinetic characterization. To the best of our knowledge, this is the first example of isolating and characterizing a potent enzyme inhibitor from a partially purified crude natural product extract using a protein crystallographic approach.

  7. [Inhibitory effects of natural medicines on the enzymes related to the skin].

    Science.gov (United States)

    Sawabe, Y; Yamasaki, K; Iwagami, S; Kajimura, K; Nakagomi, K

    1998-09-01

    In this paper, we investigated the inhibitory effects of water extracts from sixty-six natural medicines on the enzymes related to the skin, which were tyrosinase, hyaluronidase and collagenase. To clarify the inhibitory components in water extracts, tannin quantity and the inhibitory activity of the water extracts after removal of phenolic compounds using polyclar AT, were measured. Twelve kinds of natural medicines were found to have tyrosinase inhibitory activity. Six of them showed that tannin, which contains sufficient amounts in extracts, might be major inhibitory compounds due to a significant decrease of inhibition by these samples after removal of phenolic compounds. The inhibitory compound of Aurantii fructus immaturus was thought phenolic compounds except tannin. The inhibitory compounds may include Armeniacae semen, Perillae folium and Persicae semen besides a phenolic compound. Twenty-seven species among the natural medicines studied showed inhibitory activity on hyaluronidase. Phenolic compounds in these extracts except Artemisiae argyi folium, could not be candidates for hyaluronidase inhibitors. Seven kinds of the natural medicines have inhibitory activity on collagenase. It was estimated that these inhibitory compounds were phenolic compounds. These results are to be expected for finding novel compounds for skin disease or skin-care cosmetics.

  8. Natural products from resurrection plants: potential for medical applications.

    Science.gov (United States)

    Gechev, Tsanko S; Hille, Jacques; Woerdenbag, Herman J; Benina, Maria; Mehterov, Nikolay; Toneva, Valentina; Fernie, Alisdair R; Mueller-Roeber, Bernd

    2014-11-01

    Resurrection species are a group of land plants that can tolerate extreme desiccation of their vegetative tissues during harsh drought stress, and still quickly - often within hours - regain normal physiological and metabolic functions following rehydration. At the molecular level, this desiccation tolerance is attributed to basal cellular mechanisms including the constitutive expression of stress-associated genes and high levels of protective metabolites present already in the absence of stress, as well as to transcriptome and metabolome reconfigurations rapidly occurring during the initial phases of drought stress. Parts of this response are conferred by unique metabolites, including a diverse array of sugars, phenolic compounds, and polyols, some of which accumulate to high concentrations within the plant cell. In addition to drought stress, these metabolites are proposed to contribute to the protection against other abiotic stresses and to an increased oxidative stress tolerance. Recently, extracts of resurrection species and particular secondary metabolites therein were reported to display biological activities of importance to medicine, with e.g. antibacterial, anticancer, antifungal, and antiviral activities, rendering them possible candidates for the development of novel drug substances as well as for cosmetics. Herein, we provide an overview of the metabolite composition of resurrection species, summarize the latest reports related to the use of natural products from resurrection plants, and outline their potential for medical applications.

  9. Plant natural variability may affect safety assessment data.

    Science.gov (United States)

    Batista, Rita; Oliveira, Margarida

    2010-12-01

    Before market introduction, genetic engineered (GE) food products, like any other novel food product, are subjected to extensive assessment of their potential effects on human health. In recent years, a number of profiling technologies have been explored aiming to increase the probability of detecting any unpredictable unintended effect and, consequently improving the efficiency of GE food safety assessment. These techniques still present limitations associated with the interpretation of the observed differences with respect to their biological relevance and toxicological significance. In order to address this issue, in this study, we have performed 2D-gel electrophoresis of five different ears of five different MON810 maize plants and of other five of the non-transgenic near-isogenic line. We have also performed 2D-gel electrophoresis of the pool of the five protein extractions of MON810 and control lines. We have notice that, in this example, the exclusive use of data from 2D-electrophoresed pooled samples, to compare these two lines, would be insufficient for an adequate safety evaluation. We conclude that, when using "omics" technologies, it is extremely important to eliminate all potential differences due to factors not related to the ones under study, and to understand the role of natural plant-to-plant variability in the encountered differences.

  10. Plants adapted to warmer climate do not outperform regional plants during a natural heat wave.

    Science.gov (United States)

    Bucharova, Anna; Durka, Walter; Hermann, Julia-Maria; Hölzel, Norbert; Michalski, Stefan; Kollmann, Johannes; Bossdorf, Oliver

    2016-06-01

    With ongoing climate change, many plant species may not be able to adapt rapidly enough, and some conservation experts are therefore considering to translocate warm-adapted ecotypes to mitigate effects of climate warming. Although this strategy, called assisted migration, is intuitively plausible, most of the support comes from models, whereas experimental evidence is so far scarce. Here we present data on multiple ecotypes of six grassland species, which we grew in four common gardens in Germany during a natural heat wave, with temperatures 1.4-2.0°C higher than the long-term means. In each garden we compared the performance of regional ecotypes with plants from a locality with long-term summer temperatures similar to what the plants experienced during the summer heat wave. We found no difference in performance between regional and warm-adapted plants in four of the six species. In two species, regional ecotypes even outperformed warm-adapted plants, despite elevated temperatures, which suggests that translocating warm-adapted ecotypes may not only lack the desired effect of increased performance but may even have negative consequences. Even if adaptation to climate plays a role, other factors involved in local adaptation, such as biotic interactions, may override it. Based on our results, we cannot advocate assisted migration as a universal tool to enhance the performance of local plant populations and communities during climate change.

  11. Attractiveness of Michigan native plants to arthropod natural enemies and herbivores.

    Science.gov (United States)

    Fiedler, A K; Landis, D A

    2007-08-01

    The use of plants to provide nectar and pollen resources to natural enemies through habitat management is a growing focus of conservation biological control. Current guidelines frequently recommend use of annual plants exotic to the management area, but native perennial plants are likely to provide similar resources and may have several advantages over exotics. We compared a set of 43 native Michigan perennial plants and 5 frequently recommended exotic annual plants for their attractiveness to natural enemies and herbivores for 2 yr. Plant species differed significantly in their attractiveness to natural enemies. In year 1, the exotic annual plants outperformed many of the newly established native perennial plants. In year 2, however, many native perennial plants attracted higher numbers of natural enemies than exotic plants. In year 2, we compared each flowering plant against the background vegetation (grass) for their attractiveness to natural enemies and herbivores. Screening individual plant species allowed rapid assessment of attractiveness to natural enemies. We identified 24 native perennial plants that attracted high numbers of natural enemies with promise for habitat management. Among the most attractive are Eupatorium perfoliatum L., Monarda punctata L., Silphium perfoliatum L., Potentilla fruticosa auct. non L., Coreopsis lanceolata L., Spiraea alba Duroi, Agastache nepetoides (L.) Kuntze, Anemone canadensis L., and Angelica atropurpurea L. Subsets of these plants can now be tested to develop a community of native plant species that attracts diverse natural enemy taxa and provides nectar and pollen throughout the growing season.

  12. Cell organelles from crassulacean-acid-metabolism (CAM) plants : I. Enzymes in isolated peroxisomes.

    Science.gov (United States)

    Herbert, M; Burkhard, C; Schnarrenberger, C

    1978-01-01

    Cell organelles were isolated from the CAM plants Crassula lycopodioides Lam., Bryophyllum calycinum Salisb. and Sedum rubrotinctum R.T. Clausen by isopycnic centrifugation in sucrose gradients. The inclusion of 2.5% Ficoll in the grinding medium proved to be essential for a satisfactory separation of cell organelles during the subsequent centrifugation. Peroxisomes, mitochondria, and whole and broken chloroplasts were at least partially resolved as judged by marker-enzyme-activity profiles. The isolated peroxisomes contained activities of glycollate oxidase, catalase, hydroxypyruvate reductase, glycine aminotransferase, serine-glyoxylate aminotransferase, and aspartate aminotransferase, comparable to activities found in spinach (Spinacia oleracea L.) leaf peroxisomes. In contrast to spinach, however, only little, if any, particulate malate dehydrogenase activity could be attributed to isolated peroxisomes of the three CAM plants.

  13. Structural and transcriptional analysis of plant genes encoding the bifunctional lysine ketoglutarate reductase saccharopine dehydrogenase enzyme

    Directory of Open Access Journals (Sweden)

    Gu Yong Q

    2010-06-01

    Full Text Available Abstract Background Among the dietary essential amino acids, the most severely limiting in the cereals is lysine. Since cereals make up half of the human diet, lysine limitation has quality/nutritional consequences. The breakdown of lysine is controlled mainly by the catabolic bifunctional enzyme lysine ketoglutarate reductase - saccharopine dehydrogenase (LKR/SDH. The LKR/SDH gene has been reported to produce transcripts for the bifunctional enzyme and separate monofunctional transcripts. In addition to lysine metabolism, this gene has been implicated in a number of metabolic and developmental pathways, which along with its production of multiple transcript types and complex exon/intron structure suggest an important node in plant metabolism. Understanding more about the LKR/SDH gene is thus interesting both from applied standpoint and for basic plant metabolism. Results The current report describes a wheat genomic fragment containing an LKR/SDH gene and adjacent genes. The wheat LKR/SDH genomic segment was found to originate from the A-genome of wheat, and EST analysis indicates all three LKR/SDH genes in hexaploid wheat are transcriptionally active. A comparison of a set of plant LKR/SDH genes suggests regions of greater sequence conservation likely related to critical enzymatic functions and metabolic controls. Although most plants contain only a single LKR/SDH gene per genome, poplar contains at least two functional bifunctional genes in addition to a monofunctional LKR gene. Analysis of ESTs finds evidence for monofunctional LKR transcripts in switchgrass, and monofunctional SDH transcripts in wheat, Brachypodium, and poplar. Conclusions The analysis of a wheat LKR/SDH gene and comparative structural and functional analyses among available plant genes provides new information on this important gene. Both the structure of the LKR/SDH gene and the immediately adjacent genes show lineage-specific differences between monocots and dicots, and

  14. Synergistic effect of different plant cell wall degrading enzymes is important for virulence of Fusarium graminearum.

    Science.gov (United States)

    Paccanaro, Maria Chiara; Sella, Luca; Castiglioni, Carla; Giacomello, Francesca; Martinez-Rocha, Ana Lilia; D'Ovidio, Renato; Schäfer, Wilhelm; Favaron, Francesco

    2017-08-11

    Endo-polygalacturonases (PGs) and xylanases have been shown to play an important role during pathogenesis of some fungal pathogens of dicot plants, whilst their role in monocot pathogens is less defined. Pg1 and xyr1 genes of the wheat pathogen Fusarium graminearum encode the main PG and the major regulator of xylanase production, respectively. Single and double disrupted mutants for these genes were obtained to assess their contribution to fungal infection. Compared to wild-type strain, the ∆pg mutant showed a nearly abolished PG activity, slight reduced virulence on soybean seedlings but no significant difference in disease symptoms on wheat spikes; the ∆xyr mutant was strongly reduced in xylanase activity and moderately reduced in cellulase activity but was as virulent as wild-type on both soybean and wheat plants. Consequently, the ΔpgΔxyr double mutant was impaired in xylanase, PG and cellulase activities, but, differently from single mutants, was significantly reduced in virulence on both plants. These findings demonstrate that the concurrent presence of PG, xylanase and cellulase activities is necessary for full virulence. The observation that the uronides released from wheat cell wall after a F. graminearum PG treatment were largely increased by the fungal xylanases suggests that these enzymes act synergistically in deconstructing the plant cell wall.

  15. Studies on antioxidative enzymes induced by cadmium in pea plants (Pisum sativum).

    Science.gov (United States)

    Pandey, Nalini; Singh, Gaurav Kumar

    2012-03-01

    Pea plants (Pisum sativum cv. Swati) exposed to different concentration of cadmium (50,100, 200 microM Cd) under controlled glass house conditions were quantified for different physiological parameters and antioxidative enzymes. In pea plants, Cd produced a significant inhibition of growth and induced chlorosis, marginal yellowing and necrosis in young leaves, the effect being most pronounced at 200 microM Cd supply. An alteration in the activated oxygen metabolism of pea plants were also detected as evidenced by an increase in concentration of H2O2 and TBARS along with decrease in the chlorophyll and carotenoid concentration in leaves. Cadmium toxicity induced an increase in non-protein thiol, ascorbate, proline and cysteine concentration. A significant increment in the activity of SOD, APX and GR, and a decrease in CAT was observed as a result of Cd treatment. The enhanced activity of SOD and inhibition of CAT and POD produces a high build up of H2O2 which appears to be the main cause of oxidative stress due to Cd toxicity in pea plants.

  16. Effects of supplemental enzymes on apparent nutrient digestibility in rainbow trout (Oncorhynchus mykiss) fed plant-based diets

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Hjermitslev, Niels Harthøj; Ekmann, Kim Schøn;

    2010-01-01

    on the effects of enzymes in fish feed apart from phytase. Phytase works by hydrolyzing phytic acid, and numerous studies have documented that phytase supplementation increases phosphorus availability in fish fed diets with high inclusion levels of plant proteins. Plant derived proteins are increasingly used...

  17. Identification and comparative analysis of H2O2-scavenging enzymes (ascorbate peroxidase and glutathione peroxidase in selected plants employing bioinformatics approaches

    Directory of Open Access Journals (Sweden)

    Ibrahim Ilker Ozyigit

    2016-03-01

    Full Text Available Among major reactive oxygen species (ROS, hydrogen peroxide (H2O2 exhibits dual roles in plant metabolism. Low levels of H2O2 modulate many biological/physiological processes in plants; whereas, its high level can cause damage to cell structures, having severe consequences. Thus, steady-state level of cellular H2O2 must be tightly regulated. Glutathione peroxidases (GPX and ascorbate peroxidase (APX are two major ROS-scavenging enzymes which catalyze the reduction of H2O2 in order to prevent potential H2O2-derived cellular damage. Employing bioinformatics approaches, this study presents a comparative evaluation of both GPX and APX in 18 different plant species, and provides valuable insights into the nature and complex regulation of these enzymes. Herein, (a potential GPX and APX genes/proteins from 18 different plant species were identified, (b their exon/intron organization were analyzed, (c detailed information about their physicochemical properties were provided, (d conserved motif signatures of GPX and APX were identified, (e their phylogenetic trees and 3D models were constructed, (f protein-protein interaction networks were generated, and finally (g GPX and APX gene expression profiles were analyzed. Study outcomes enlightened GPX and APX as major H2O2-scavenging enzymes at their structural and functional levels, which could be used in future studies in the current direction.

  18. Enzymes of phenylpropanoid metabolism in the important medicinal plant Melissa officinalis L.

    Science.gov (United States)

    Weitzel, Corinna; Petersen, Maike

    2010-08-01

    Lemon balm (Melissa officinalis, Lamiaceae) is a well-known medicinal plant. Amongst the biologically active ingredients are a number of phenolic compounds, the most prominent of which is rosmarinic acid. To obtain better knowledge of the biosynthesis of these phenolic compounds, two enzymes of the general phenylpropanoid pathway, phenylalanine ammonia-lyase (PAL) and 4-coumarate:coenzyme A-ligase (4CL), were investigated in suspension cultures of lemon balm. MoPAL1 and Mo4CL1 cDNAs were cloned and heterologously expressed in Escherichia coli and the enzymes characterised. Expression analysis of both genes showed a correlation with the enzyme activities and rosmarinic acid content during a cultivation period of the suspension culture. Southern-blot analysis suggested the presence of most probably two gene copies in the M. officinalis genome of both PAL and 4CL. The genomic DNA sequences of MoPAL1 and Mo4CL1 were amplified and sequenced. MoPAL1 contains one phase 2 intron of 836 bp at a conserved site, whilst Mo4CL1 was devoid of introns.

  19. Plant degreening: evolution and expression of tomato (Solanum lycopersicum) dephytylation enzymes.

    Science.gov (United States)

    Lira, Bruno Silvestre; de Setta, Nathalia; Rosado, Daniele; Almeida, Juliana; Freschi, Luciano; Rossi, Magdalena

    2014-08-10

    Chlorophyll is the most abundant pigment on earth and even though it is known that its high photo-excitability necessitates a tight regulation of its degradation pathway, to date there are still several steps in chlorophyll breakdown that remain obscure. In order to better understand the 'degreening' processes that accompany leaf senescence and fruit ripening, we characterized the enzyme-encoding genes involved in dephytylation from tomato (Solanum lycopersicum). A single pheophytinase (PPH) gene and four chlorophyllase (CLH) genes were identified in the tomato genome. A phenetic analysis revealed two groups of CLHs in eudicot species and further evolutionary analysis indicated that these enzymes are under diverse selection pressures. A comprehensive expression profile analysis also suggested functional specificity for these dephytylating enzymes. The integrated analysis allows us to propose three general roles for chlorophyll dephytylation: i) PPH, which is under high selective constraint, is responsible for chlorophyll degradation during developmentally programed physiological processes; ii) Group I CLHs, which are under relaxed selection constraint, respond to environmental and hormonal stimuli and play a role in plant adaptation plasticity; and iii) Group II CLHs, which are also under high selective constraint, are mostly involved in chlorophyll recycling. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Induced and constitutive responses of digestive enzymes to plant toxins in an herbivorous mammal.

    Science.gov (United States)

    Kohl, Kevin D; Dearing, M Denise

    2011-12-15

    Many plants produce plant secondary compounds (PSCs) that bind and inhibit the digestive enzymes of herbivores, thus limiting digestibility for the herbivore. Herbivorous insects employ several physiological responses to overcome the anti-nutritive effects of PSCs. However, studies in vertebrates have not shown such responses, perhaps stemming from the fact that previously studied vertebrates were not herbivorous. The responses of the digestive system to dietary PSCs in populations of Bryant's woodrat (Neotoma bryanti) that vary in their ecological and evolutionary experience with the PSCs in creosote bush (Larrea tridentata) were compared. Individuals from naïve and experienced populations were fed diets with and without added creosote resin. Animals fed diets with creosote resin had higher activities of pancreatic amylase, as well as luminal amylase and chymotrypsin, regardless of prior experience with creosote. The experienced population showed constitutively higher activities of intestinal maltase and sucrase. Additionally, the naïve population produced an aminopeptidase-N enzyme that was less inhibited by creosote resin when feeding on the creosote resin diet, whereas the experienced population constitutively expressed this form of aminopeptidase-N. Thus, the digestive system of an herbivorous vertebrate responds significantly to dietary PSCs, which may be important for allowing herbivorous vertebrates to feed on PSC-rich diets.

  1. Cloning of the Arabidopsis and Rice Formaldehyde Dehydrogenase Genes: Implications for the Origin of Plant Adh Enzymes

    Science.gov (United States)

    Dolferus, R.; Osterman, J. C.; Peacock, W. J.; Dennis, E. S.

    1997-01-01

    This article reports the cloning of the genes encoding the Arabidopsis and rice class III ADH enzymes, members of the alcohol dehydrogenase or medium chain reductase/dehydrogenase superfamily of proteins with glutathione-dependent formaldehyde dehydrogenase activity (GSH-FDH). Both genes contain eight introns in exactly the same positions, and these positions are conserved in plant ethanol-active Adh genes (class P). These data provide further evidence that plant class P genes have evolved from class III genes by gene duplication and acquisition of new substrate specificities. The position of introns and similarities in the nucleic acid and amino acid sequences of the different classes of ADH enzymes in plants and humans suggest that plant and animal class III enzymes diverged before they duplicated to give rise to plant and animal ethanol-active ADH enzymes. Plant class P ADH enzymes have gained substrate specificities and evolved promoters with different expression properties, in keeping with their metabolic function as part of the alcohol fermentation pathway. PMID:9215914

  2. AIR POLLUTION EFFECTS ON THE ACTIVITY OF ANTIOXIDANT ENZYMES IN NERIUM OLEANDER AND ROBINIA PSEUDO ACACIA PLANTS IN TEHRAN

    Directory of Open Access Journals (Sweden)

    M. Ghorbanli, Z. Bakand, G. Bakhshi khaniki, S. Bakand

    2007-07-01

    Full Text Available The air pollution effects on the activity of antioxidant enzymes were investigated on Nerium oleander and Robinia pseudo acacia in Tehran. Considering the information obtained from the Department of the Environment of Iran, Sorkh Hesar Park as well as South Azadi were selected as two sampling sites representing the unpolluted and polluted area respectively. A number of plant leave samples were collected from both sampling sites simultaneously. The activity of plant enzymes including peroxidase, catalase and ascorbate peroxidase was investigated using spectrophotometric methods. A higher level of peroxidase and catalase enzymes were measured in both plant samples collected from polluted area. However, this higher level was only statistically significant for the activity of peroxidase enzyme in Robinia pseudo acacia plants compare of to the control group (p < 0.05. The lower level of ascorbate peroxidase was observed in Nerium oleander plant leaves collected from the contaminated sampling site (p < 0.05, but though, the activity of this enzyme in Robinia pseudo acacia did not change significantly. The overall plant injury symptoms found in this study demonstrated that both Nerium oleander and Robinia pseudo acacia have a potential to be considered as effective bioindicators to reflect the environmental air quality in polluted areas.

  3. Bacterial Glycosyltransferases: Challenges and opportunities of a highly diverse enzyme class toward tailoring natural products

    Directory of Open Access Journals (Sweden)

    Jochen eSchmid

    2016-02-01

    Full Text Available The enzyme subclass of glycosyltransferases (EC 2.4 currently comprises 97 families as specified by CAZy classification. One of their important roles is in the biosynthesis of disaccharides, oligosaccharides and polysaccharides by catalyzing the transfer of sugar moieties from activated donor molecules to other sugar molecules. In addition glycosyltransferases also catalyze the transfer of sugar moieties onto aglycons, which is of great relevance for the synthesis of many high value natural products. Bacterial glycosyltransferases show a higher sequence similarity in comparison to mammalian ones. Even when most glycosyltransferases are poorly explored, state of the art technologies, such as protein engineering, domain swapping or computational analysis strongly enhance our understanding and utilization of these very promising classes of proteins. This perspective article will focus on bacterial glycosyltransferases, especially on classification, screening and engineering strategies to alter substrate specificity. The future development in these fields as well as obstacles and challenges will be highlighted and discussed.

  4. Unused natural variation can lift yield barriers in plant breeding.

    Directory of Open Access Journals (Sweden)

    Amit Gur

    2004-10-01

    Full Text Available Natural biodiversity is an underexploited sustainable resource that can enrich the genetic basis of cultivated plants with novel alleles that improve productivity and adaptation. We evaluated the progress in breeding for increased tomato (Solanum lycopersicum yield using genotypes carrying a pyramid of three independent yield-promoting genomic regions introduced from the drought-tolerant green-fruited wild species Solanum pennellii. Yield of hybrids parented by the pyramided genotypes was more than 50% higher than that of a control market leader variety under both wet and dry field conditions that received 10% of the irrigation water. This demonstration of the breaking of agricultural yield barriers provides the rationale for implementing similar strategies for other agricultural organisms that are important for global food security.

  5. Novel fermentation processes for manufacturing plant natural products.

    Science.gov (United States)

    Zhou, Jingwen; Du, Guocheng; Chen, Jian

    2014-02-01

    Microbial production of plant natural products (PNPs), such as terpenoids, flavonoids from renewable carbohydrate feedstocks offers sustainable and economically attractive alternatives to their petroleum-based production. Rapid development of metabolic engineering and synthetic biology of microorganisms shows many advantages to replace the current extraction of these useful high price chemicals from plants. Although few of them were actually applied on a large scale for PNPs production, continuous research on these high-price chemicals and the rapid growing global market of them, show the promising future for the production of these PNPs by microorganisms with a more economic and environmental friendly way. Introduction of novel pathways and optimization of the native cellular processes by metabolic engineering of microorganisms for PNPs production are rapidly expanding its range of cell-factory applications. Here we review recent progress in metabolic engineering of microorganisms for the production of PNPs. Besides, factors restricting the yield improvement and application of lab-scale achievements to industrial applications have also been discussed.

  6. Enzyme Inhibitory Properties, Antioxidant Activities, and Phytochemical Profile of Three Medicinal Plants from Turkey

    Directory of Open Access Journals (Sweden)

    Gokhan Zengin

    2015-01-01

    Full Text Available We aimed to investigate the inhibitory potential of three medicinal plants (Hedysarum varium, Onobrychis hypargyrea, and Vicia truncatula from Turkey against key enzymes involved in human pathologies, namely, diabetes (α-amylase and α-glucosidase, neurodegenerative disorders (tyrosinase, acetylcholinesterase, and butyrylcholinesterase, and hyperpigmentation (tyrosinase. The antioxidant potential, phenolic and flavonoid content of ethyl acetate, and methanolic and aqueous extracts were investigated using in vitro assays. The total antioxidant capacity (TAC, β-carotene/linoleic acid bleaching activity, 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH•, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+, cupric ion reducing antioxidant capacity (CUPRAC, ferric reducing antioxidant power (FRAP, and metal chelating activity on ferrous ions were used to evaluate the antioxidant capabilities of the extracts. The half-maximal inhibitory concentrations (IC50 of the extracts on cholinesterase, tyrosinase, and α-amylase were significantly higher than the references, galantamine, kojic acid, and acarbose, respectively. The half-maximal effective concentrations (EC50 of the extracts on TAC, CUPRAC, and FRAP were significantly higher than trolox. The phenol and flavonoid contents of the plant extracts were in the range 20.90±0.190–83.25±0.914 mg gallic acid equivalent/g extract and 1.45±0.200–39.71±0.092 mg rutin equivalent/g extract, respectively. The plants were found to possess moderate antioxidant capacities and interesting inhibitory action against key enzymes.

  7. Multifactorial nature of hepatocellular carcinoma drug resistance: Could plant polyphenols be helpful?

    Institute of Scientific and Technical Information of China (English)

    Natale D'Alessandro; Paola Poma; Giuseppe Montalto

    2007-01-01

    Primary hepatocellular carcinoma (HCC) is a quite frequent tumor which results in high mortality and most often exhibits a poor response to present drug therapies. Clearly, a thorough understanding of the biological bases of this malignancy might suggest new strategies for its treatment. Here we examine the evidences that both "pharmacological" mechanisms (e.g. Drug transporter or detoxification enzyme over-expression) and alterations in other critical factors, including the IAPs (Inhibitory of Apoptosis Proteins), involved in enhancement of cell survival and proliferation may determine the therapeutic resistance of HCC; we also underline the possible role in the process of the activation of transcription factors, like NF-κB, capable of contemporaneously up-regulating the mechanisms discussed. On this basis, we finally comment on the possible use of natural multi-targeted antitumoral agents like plant polyphenols to achieve sensitization to treatments in HCC.

  8. Nitrate dynamics in natural plants: Insights based on the concentration and natural isotope abundances of tissue nitrate

    Directory of Open Access Journals (Sweden)

    Xue Yan Liu

    2014-07-01

    Full Text Available The dynamics of nitrate (NO3-, a major nitrogen (N source for natural plants, has been studied mostly through experimental N addition, enzymatic assay, isotope labeling, and genetic expression. However, artificial N supply may not reasonably reflect the N strategies in natural plants because NO3- uptake and reduction may vary with external N availability. Abrupt application and short operation times, field N addition, and isotopic labeling hinder the elucidation of in situ NO3--use mechanisms. The concentration and natural isotopes of tissue NO3- can offer insights into the plant NO3- sources and dynamics in a natural context. Furthermore, they facilitate the exploration of plant NO3- utilization and its interaction with N pollution and ecosystem N cycles without disturbing the N pools. The present study was conducted to review the application of the denitrifier method for concentration and isotope analyses of NO3- in plants. Moreover, this study highlights the utility and benefits of these parameters in interpreting NO3- sources and dynamics in natural plants. We summarize the major sources and reduction processes of NO3- in plants, and discuss the implications of NO3- concentration in plant tissues based on existing data. Particular emphasis was laid on the regulation of soil NO3 - and plant ecophysiological functions in interspecific and intra-plant NO3- variations. We introduce N and O isotope systematics of NO3- in plants and discusse the principles and feasibilities of using isotopic enrichment and fractionation factors; the correlation between concentration and isotopes (N and O isotopes: δ18O and ∆17O; and isotope mass-balance calculations to constrain sources and reduction of NO3- in possible scenarios for natural plants are deliberated. Finally, we construct a preliminary framework of intraplant δ18O-NO3- variation, and summarize the uncertainties in using tissue NO3- parameters to interpret plant NO3- utilization.

  9. Natural products inhibitors of the enzyme acetylcholinesterase Produtos naturais inibidores da enzima acetilcolinesterase

    Directory of Open Access Journals (Sweden)

    José M. Barbosa Filho

    2006-06-01

    Full Text Available Alzheimer's disease (AD is a progressive, neurodegenerative pathology that primarily affects the elderly population, and is estimated to account for 50-60% of dementia cases in persons over 65 years of age. The main symptoms associated with AD involve cognitive dysfunction, primarily memory loss. Other features associated with the later stages of AD include language deficits, depression, behavioural problems including agitation, mood disturbances and psychosis. One of the most promising approaches for treating this disease is to enhance the acetylcholine level in the brain using acetylcholinesterase (AChE inhibitors. The present work reviews the literature on plants and plant-derived compounds inhibitors of enzyme acetylcholinesterase. The review refers to 309 plant extracts and 260 compounds isolated from plants, which are classified in appropriate chemical groups and model tested, and cites their activity. For this purpose 175 references were consulted.A Doença de Alzheimer (DA é uma patologia neurodegenerativa, progressiva, que afeta principalmente a população idosa, responsável por 50-60% dos casos de demência em pessoas com mais de 65 anos de idade. Os principais sintomas associado a DA envolve deficiência orgânica cognitiva, principalmente perda de memória. Outras características associadas com os estágios avançados de DA inclui déficit na linguagem, depressão, problemas de comportamento, inclusive agitação, alterações de humor e psicose.Um dos mais promissores caminhos para tratar esta doença é aumentar o nível de acetilcolina no cérebro usando inibidores da acetilcolinesterase (AChE. Este trabalho teve como objetivo revisar a literatura das plantas e substâncias encontradas nas plantas, inibidores da enzima acetilcolinesterase. Foram levantadas 309 plantas e 260 substâncias isoladas de plantas que foram classificados em grupos químicos adequados, os modelo testados, e suas atividades. Foram consultados 175 referências.

  10. In vitro study of natural plant products against oral bacteria

    Institute of Scientific and Technical Information of China (English)

    Siddiqui R; Siti AsmaH; Tang L; Jie CC; Rosliza AR; Roziawati Y

    2009-01-01

    Objective:To analyze the effect of selected plant product against several bacterial which commonly causes oral infection.It was hope that in future,this product will become the remedy for treatment of oral infection and with the hope that it can substitute antibiotics.Methods:A total of 5 species of oral bacteria from American Type Culture Collection (ATCC)were employed in this study(S.mutans,S.aureus,P.aeruginosa,S.sobri-nus and L.salivarius).Three types of natural plants crude extracts were used (garlic,curry leaves and cloves).Bactericidal and bacteriostatic effects of these herbs were tested.Results:It was shown garlic had an-tibacterial effects on all bacteria.The Minimal Inhibitory Concentration (MIC in g/mL)of garlic towards S. aureus,P.aeruginosa,S.mutans,S.sobrinus and L.salivarius were 0.3,1.8,1.2,0.5 and 1.8,respectively. There was significant difference among the MIC of garlic on tested bacteria.It was more potent toward S.au-reus.The curry leaf solution on the other hand,did not show any zone of inhibition in all bacteria plates but adversely showed enhanced growth of those bacteria.Clove had shown its antibacterial effects on S.aureus and P.aeruginosa.The clove was more potent toward S.aureus with the MIC of 0.45 g/mL.P.aeruginosa was more sensitive to clove compared to garlic.For S.aureus,it was more sensitive to garlic compared to clove. Conclusion:The antibacterial activity of garlic and clove crude extracts shown in our study further confirm these natural plants'potential usage in therapeutic use for oral diseases or infections.This could be the platform for the interested party to do research and development on it and to produce oral health products which are more affordable for lower economic income groups and with fewer side effects as seen in synthetic drug.

  11. Reduced Dental Plaque Formation in Dogs Drinking a Solution Containing Natural Antimicrobial Herbal Enzymes and Organic Matcha Green Tea

    Directory of Open Access Journals (Sweden)

    Michael I. Lindinger

    2016-01-01

    Full Text Available The results of an exploratory, multicenter clinical study confirmed the hypothesis that a novel, natural, and safe oral care product (OCP reduced the rate of plaque formation on teeth of dogs consuming the OCP (antimicrobial plant-derived enzymes, organic matcha green tea, cultured dextrose, sodium bicarbonate, and ascorbic acid compared to controls. Healthy dogs without periodontitis, of varying breeds, sex, and age, were recruited and enrolled, using nonrandomized stratification methods, into a control and treatment groups. Treatment group dogs drank only water into which OCP was suspended, for 28 days. Control group dogs drank their normal household water. On day 0 all teeth were cleaned by a veterinarian and gingivitis was assessed. On days 14, 21, and 28 plaque index, plaque thickness, gingivitis, freshness of breath, and general health were assessed. Over the 28 days of study, dogs on the OCP had significant reduction in plaque index and plaque thickness compared to controls. By day 14 OCP reduced plaque formation by 37%; the 28-day reduction in plaque index and coverage averaged 22% with no measurable gingivitis or calculus. Conclusion. Using the OCP attenuated dental plaque formation when consumed as normal drinking water and in the absence of other modes of oral care.

  12. Reduced Dental Plaque Formation in Dogs Drinking a Solution Containing Natural Antimicrobial Herbal Enzymes and Organic Matcha Green Tea.

    Science.gov (United States)

    Lindinger, Michael I

    2016-01-01

    The results of an exploratory, multicenter clinical study confirmed the hypothesis that a novel, natural, and safe oral care product (OCP) reduced the rate of plaque formation on teeth of dogs consuming the OCP (antimicrobial plant-derived enzymes, organic matcha green tea, cultured dextrose, sodium bicarbonate, and ascorbic acid) compared to controls. Healthy dogs without periodontitis, of varying breeds, sex, and age, were recruited and enrolled, using nonrandomized stratification methods, into a control and treatment groups. Treatment group dogs drank only water into which OCP was suspended, for 28 days. Control group dogs drank their normal household water. On day 0 all teeth were cleaned by a veterinarian and gingivitis was assessed. On days 14, 21, and 28 plaque index, plaque thickness, gingivitis, freshness of breath, and general health were assessed. Over the 28 days of study, dogs on the OCP had significant reduction in plaque index and plaque thickness compared to controls. By day 14 OCP reduced plaque formation by 37%; the 28-day reduction in plaque index and coverage averaged 22% with no measurable gingivitis or calculus. Conclusion. Using the OCP attenuated dental plaque formation when consumed as normal drinking water and in the absence of other modes of oral care.

  13. Plant diversity reduces the effect of multiple heavy metal pollution on soil enzyme activities and microbial community structure

    Institute of Scientific and Technical Information of China (English)

    Yang GAO; Chiyuan MIAO; Jun XIA; Liang MAO; Yafeng WANG; Pei ZHOU

    2012-01-01

    It is unclear whether certain plant species and plant diversity could reduce the impacts of multiple heavy metal pollution on soil microbial structure and soil enzyme activities. Random amplified polymorphic DNA (RAPD) was used to analyze the genetic diversity and microbial similarity in planted and unplanted soil under combined cadmium (Cd) and lead (Pb) pollution. A metal hyper- accumulator, Brassica juncea, and a common plant, Festuca arundinacea Schreb, were used in this research. The results showed that microorganism quantity in planted soil significantly increased, compared with that in unplanted soil with Cd and Pb pollution. The order of microbial community sensitivity in response to Cd and Pb stress was as follows: actinomycetes 〉 bacteria 〉 fungi. Respiration, phosphatase, urease and dehydrogenase activity were significantly inhibited due to Cd and Pb stress. Compared with unplanted soil, planted soils have frequently been reported to have higher rates of microbial activity due to the presence of additional surfaces for microbial colonization and organic compounds released by the plant roots. Two coexisting plants could increase microbe population and the activity of phosphatases, dehydrogenases and, in particular, ureases. Soil enzyme activity was higher in B. juncea phytoremediated soil than in F. arundinacea planted soil in this study. Heavy metal pollution decreased the richness of the soil microbial community, but plant diversity increased DNA sequence diversity and maintained DNA sequence diversity at highlevels. The genetic polymorphism under heavy metal stress was higher in B. juncea phytoremediated soil than in F. arundinacea planted soil.

  14. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes.

    Science.gov (United States)

    Piśkiewicz, Anna M; Duyts, Henk; Berg, Matty P; Costa, Sofia R; van der Putten, Wim H

    2007-06-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis is capable of reducing the performance of the dominant grass Ammophila arenaria (Marram grass). However, field surveys show that populations of this nematode usually are controlled to nondamaging densities, but the control mechanism is unknown. In the present study, we first established that T. ventralis populations are top-down controlled by soil biota. Then, selective removal of soil fauna suggested that soil microorganisms play an important role in controlling T. ventralis. This result was confirmed by an experiment where selective inoculation of microarthropods, nematodes and microbes together with T. ventralis into sterilized dune soil resulted in nematode control when microbes were present. Adding nematodes had some effect, whereas microarthropods did not have a significant effect on T. ventralis. Our results have important implications for the appreciation of herbivore controls in natural soils. Soil food web models assume that herbivorous nematodes are controlled by predaceous invertebrates, whereas many biological control studies focus on managing nematode abundance by soil microorganisms. We propose that soil microorganisms play a more important role than do carnivorous soil invertebrates in the top-down control of herbivorous ectoparasitic nematodes in natural ecosystems. This is opposite to many studies on factors controlling root-feeding insects, which are supposed to be controlled by carnivorous invertebrates, parasitoids, or entomopathogenic nematodes. Our conclusion is that the ectoparasitic nematode T. ventralis is potentially able to limit productivity of the dune grass A. arenaria but that soil organisms, mostly microorganisms, usually prevent the

  15. Effects of plant enzyme inactivation or sterilization on lipolysis and proteolysis in alfalfa silage.

    Science.gov (United States)

    Ding, W R; Long, R J; Guo, X S

    2013-04-01

    This experiment studied the contribution of plant enzymes and microbial activity on lipolysis and proteolysis in ensiled alfalfa. Before ensiling, the wilted alfalfa was treated with plant enzyme inactivation by autoclaving or with sterilization by γ-ray irradiation. The treated alfalfa was then inoculated with commercial lactic acid bacteria inoculants and ensiled for 40 d. Alfalfa without treatment was ensiled as the control. The content of total fatty acid (FA) after ensiling decreased 43% in the control silage and 28% in the γ-ray-treated silage, but did not change in the autoclave-treated silage. Among the major FA (C16:0, C18:2n-6, C18:3n-3), a considerable increase was observed in proportion of C16:0 in the control silage as compared with fresh alfalfa; conversely, decreases in proportions of C18:2n-6 and C18:3n-3 occurred during ensilage. Silage treated with γ-ray radiation at ensiling had a smaller proportion of C16:0 and greater proportions of C18:2n-6 and C18:3n-3 than control silage. Autoclave treatment further decreased proportions of C16:0 and most of the other FA, and increased C18:2n-6 and C18:3n-3 proportions in comparison with γ-ray treatment. Proportions of C16:0, C18:2n-6, C18:3n-3 and other detected FA (except for the proportion of C15:0) did not differ between fresh forage and autoclave-treated silage. Remarkably, smaller nonprotein nitrogen content was observed in the autoclave-treated silage compared with the γ ray-treated silage or the control silage. These results indicated that an extensive lipolysis occurred during ensiling of alfalfa, and plant enzymes played a major role in lipolysis and proteolysis. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Changes in antioxidant enzymes activities and proline, total phenol and anthocyanine contents in Hyssopus officinalis L. plants under salt stress.

    Science.gov (United States)

    Jahantigh, Omolbanin; Najafi, Farzaneh; Badi, Hassanali Naghdi; Khavari-Nejad, Ramazan Ali; Sanjarian, Forough

    2016-06-01

    The relationships between salt stress and antioxidant enzymes activities, proline, phenol and anthocyanine contents in Hyssopus officinalis L. plants in growth stage were investigated. The plants were subjected to five levels of saline irrigation water, 0.37 (tap water as control) with 2, 4, 6, 8 and 10 dSm(-1) of saline water. After two months the uniform plants were harvested for experimental analysis. Antioxidant enzymes activities and proline, phenol and anthocyanine contents of the plants were examinated. Enhanced activities of peroxidase, catalase and superoxide dismutase were determined by increasing salinity that plays an important protective role in the ROS-scavenging process. Proline, phenol and anthocyanine contents increased significantly with increasing salinity. These results suggest that salinity tolerance of Hyssopus officinalis plants might be closely related with the increased capacity of antioxidative system to scavenge reactive oxygen species and with the accumulation of osmoprotectant proline, phenol and anthocyanine contents under salinity conditions.

  17. Nanolipoprotein particles comprising a natural rubber biosynthetic enzyme complex and related products, methods and systems

    Energy Technology Data Exchange (ETDEWEB)

    Hoeprich, Paul D.; Whalen, Maureen

    2016-04-05

    Provided herein are nanolipoprotein particles that comprise a biosynthetic enzyme more particularly an enzyme capable of catalyzing rubber or other rubbers polymerization, and related assemblies, devices, methods and systems.

  18. Natural product juglone targets three key enzymes from Helicobacter pylori: inhibition assay with crystal structure characterization

    Institute of Scientific and Technical Information of China (English)

    Yun-hua KONG; Liang ZHANG; Zheng-yi YANG; Cong HAN; Li-hong HU; Hua-liang JIANG; Xu SHEN

    2008-01-01

    Aim: To investigate the inhibition features of the natural product juglone (5-hydroxy-1,4-naphthoquinone) against the three key enzymes from Helicobacter pylori (cystathionine γ-synthase [HpCGS], malonyl-CoA:acyl carrier protein transacylase [HpFabD], and β-hydroxyacyl-ACP dehydratase [HpFabZ]). Methods: An enzyme inhibition assay against HpCGS was carded out by using a continuous coupled spectrophotometric assay approach. The inhibition assay of HpFabD was performed based on the α-ketoglutarate dehydrogenase-coupled system, while the inhibition assay for HpFabZ was monitored by detecting the decrease in absorbance at 260 nm with crotonoyl-CoA conversion to βhydroxybutyryl-CoA. The juglone/FabZ complex crystal was obtained by soaking juglone into the HpFabZ crystal, and the X-ray crystal structure of the complex was analyzed by molecular replacement approach. Results: Juglone was shown to potently inhibit HpCGS, HpFabD, and HpFabZ with the half maximal inhibitory concentration IC50 values of 7.0±0.7, 20±1, and 30±4 μmol/L, respectively. An inhibition-type study indicated that juglone was a non-competitive inhibitor of HpCGS against O-succi-nyl-L-homoserine (KI=αKI=24 μmol/L), an uncompetitive inhibitor of HpFabD against malonyl-CoA (αKI=7.4 μmol/L), and a competitive inhibitor of HpFabZ against crotonoyl-CoA (K,1=6.8 μtmol/L). Moreover, the crystal structure of the HpFabZ/juglone complex further revealed the essential binding pattern ofjuglone against HpFabZ at the atomic level. Conclusion: HpCGS, HpFabD, and HpFabZ are potential targets ofjuglone.

  19. The Natural Antimicrobial Enzyme Lysozyme is Up-Regulated in Gastrointestinal Inflammatory Conditions

    Directory of Open Access Journals (Sweden)

    Carlos A. Rubio

    2014-01-01

    Full Text Available The cells that line the mucosa of the human gastrointestinal tract (GI, that is, oral cavity, oesophagus, stomach, small intestine, large intestine, and rectum are constantly challenged by adverse micro-environmental factors, such as different pH, enzymes, and bacterial flora. With exception of the oral cavity, these microenvironments also contain remnant cocktails of secreted enzymes and bacteria from upper organs along the tract. The density of the GI bacteria varies, from 103/mL near the gastric outlet, to 1010/mL at the ileocecal valve, to 1011 to 1012/mL in the colon. The total microbial population (ca. 1014 exceeds the total number of cells in the tract. It is, therefore, remarkable that despite the prima facie inauspicious mixture of harmful secretions and bacteria, the normal GI mucosa retains a healthy state of cell renewal. To counteract the hostile microenvironment, the GI epithelia react by speeding cell exfoliation (the GI mucosa has a turnover time of two to three days, by increasing peristalsis, by eliminating bacteria through secretion of plasma cell-immunoglobulins and by increasing production of natural antibacterial compounds, such as defensin-5 and lysozyme. Only recently, lysozyme was found up-regulated in Barrett’s oesophagitis, chronic gastritis, gluten-induced atrophic duodenitis (coeliac disease, collagenous colitis, lymphocytic colitis, and Crohn’s colitis. This up-regulation is a response directed to the special types of bacteria recently detected in these diseases. The aim of lysozyme up-regulation is to protect individual mucosal segments to chronic inflammation. The molecular mechanisms connected to the crosstalk between the intraluminal bacterial flora and the production of lysozyme released by the GI mucosae, are discussed. Bacterial resistance continues to exhaust our supply of commercial antibiotics. The potential use of lysozyme to treat infectious diseases is receiving much attention.

  20. Carica papaya lipase: a naturally immobilized enzyme with interesting biochemical properties.

    Science.gov (United States)

    Abdelkafi, Slim; Barouh, Nathalie; Fouquet, Benjamin; Fendri, Imen; Pina, Michel; Scheirlinckx, Frantz; Villeneuve, Pierre; Carrière, Frédéric

    2011-03-01

    Triacylglycerol (TAG) lipases have been thoroughly characterized in mammals and microorganisms, whereas very little is known about plant TAG lipases. The lipolytic activity occurring in all the laticies is known to be associated with sedimentable particles, and all attempts to solubilize the lipolytic activity of Carica papaya latex have been unsuccessful so far. However, some of the biochemical properties of the lipase from Carica papaya latex (CPL) were determined from the insoluble fraction of the latex. The activity was optimum at a temperature of 37°C and a pH of 9.0, and the specific activities of CPL were found to be 2,000 ± 185 and 256 ± 8 U/g when tributyrin and olive oil were used as substrates, respectively. CPL was found to be active in the absence of any detergent, whereas many lipases require detergent to prevent the occurrence of interfacial denaturation. CPL was inactive in the presence of micellar concentrations of Triton X-100, sodium dodecyl sulfate (SDS) and tetradecyl trimethylammonium bromide (TTAB), and still showed high levels of activity in the presence of sodium taurodeoxycholate (NaTDC) and the zwitterionic Chaps detergent. The effects of various proteases on the lipolytic activity of CPL were studied, and CPL was found to be resistant to treatment with various enzymes, except in the presence of trypsin. All these properties suggest that CPL may be a good candidate for various biotechnological applications.

  1. Artificial and natural thermostabilization of subunit enzymes. Do they have similar mechanism?

    Science.gov (United States)

    Trubetskoy, V S; Torchilin, V P

    1985-01-01

    Rabbit skeletal muscle glyceraldehyde-3-phosphate dehydrogenase was stabilized by intramolecular intersubunit crosslinking with diimidoesters. Half-inactivation temperature for optimal cross-linker-treated enzyme preparation increased by 11 degrees C. Stabilization effect correlated with the content of crosslinked fractions in enzyme preparation, as proved by SDS gel-electrophoresis. It is proposed that artificial crosslinks stabilize the enzyme in a similar fashion to salt bridges in the thermophilic bacteria enzymes, i.e. preventing dissociation into inactive subunits.

  2. Carbonic anhydrase: a key regulatory and detoxifying enzyme for Karst plants.

    Science.gov (United States)

    Müller, Werner E G; Qiang, Li; Schröder, Heinz C; Hönig, Natalie; Yuan, Daoxian; Grebenjuk, Vlad A; Mussino, Francesca; Giovine, Marco; Wang, Xiaohong

    2014-01-01

    Karstification is a rapid process during which calcidic stones/limestones undergo dissolution with the consequence of a desertification of karst regions. A slow-down of those dissolution processes of Ca-carbonate can be approached by a reforestation program using karst-resistant plants that can resist alkaline pH and higher bicarbonate (HCO₃⁻) concentrations in the soil. Carbonic anhydrases (CA) are enzymes that mediate a rapid and reversible interconversion of CO₂ and HCO₃⁻. In the present study, the steady-state expression of a CA gene, encoding for the plant carbonic anhydrase from the parsley Petroselinum crispum, is monitored. The studies were primarily been performed during germination of the seeds up to the 12/14-day-old embryos. The CA cDNA was cloned. Quantitative polymerase chain reaction (qPCR) analysis revealed that the gene expression level of the P. crispum CA is strongly and significantly affected at more alkaline pH in the growth medium (pH 8.3). This abolishing effect is counteracted both by addition of HCO₃⁻ and by addition of polyphosphate (polyP) to the culture medium. In response to polyP, the increased pH in the vacuoles of the growing plants is normalized. The effect of polyP let us to propose that this polymer acts as a buffer system that facilitates the adjustment of the pH in the cytoplasm. In addition, it is proposed that polyP has the potential to act, especially in the karst, as a fertilizer that allows the karstic plants to cope with the adverse pH and HCO₃⁻ condition in the soil.

  3. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

    Energy Technology Data Exchange (ETDEWEB)

    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

  4. Activity of Stress-related Antioxidative Enzymes in the Invasive Plant Crofton Weed(Eupatorium adenophorum)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Crofton weed is an Invasive weed in southwestern China.The activities of several antioxidative enzymes involved in plant protection against oxidative stress were assayed to determine physiological aspects of the crofton weed that might render the plant vulnerable to environmental stress.Stresses imposed on crofton weed were heat (progressively increasing temperatures:25℃,30℃,35℃.38℃ and 42℃ at 24 h intervals),cold(progressively decreasing temperatures:25℃,20℃,15℃,10℃ and 5℃ at 24h intervals),and drought(without watering up to 4 days).The three stresses induced oxidative damage as evidenced by an increase in lipid peroxidation.The effect varied with the stress imposed and the length of exposure.The activity of superoxide dismutase(SOD)increased in response to all stresses but was not significantly different from the controls(P<0.05) when exposed to cold stress.Catalase (CAT)activity decreased in response to heat and drought stress but increased when exposed to cold conditions.Guaiacol peroxidase(POD) and glutathione reductase (GR)activities increased in response to cold and drought but decreased in response to heat stress.The activity of ascorbate peroxidase(APX) responded differently to all three stresses.Monodehydroascorbate reductase (MDHAR)activity decreased in response to heat and drought,and slightly increased in response to the cold stress but was not significantly different from the controls (P<0.05).The activity of dehydroascorbate reductase(DHAR)increased in response to all three stresses.Taken together,the co-ordinate increase of the oxygen-detoxifying enzymes might be more effective to protect crofton weed from the accumulation of oxygen radicals at low temperatures rather than at high temperatures.

  5. Employing bifunctional enzymes for enhanced extraction of bioactives from plants: flavonoids as an example.

    Science.gov (United States)

    Xu, Ming-Shu; Chen, Shuo; Wang, Wen-Quan; Liu, Si-Qin

    2013-08-21

    A cost-effective and environmentally friendly approach was developed to improve the extraction of active ingredients from plants, in which a bifunctional enzyme was employed for not only facilitating cell wall degradation but also increasing the bioactivity of target compounds in the extract. In the aqueous extraction of flavonoids from Glycyrrhizae radix, Trichoderma viride cellulase, a commercial cell-wall-degrading enzyme, was found to efficiently deglycosylate liquiritin and isoliquiritin, which are of high content but low bioactivity, into their aglycones that have much higher physiological activities for dietary and medicinal uses. Under optimized conditions, the extraction yield of liquiritigenin and isoliquiritigenin aglycones reached 4.23 and 0.39 mg/g of dry weight (dw) with 6.51- and 3.55-fold increases, respectively. The same approach was expanded to the extraction of flavonoids from Scutellariae radix using Penicillium decumbens naringinase, where enhanced production of more bioactive bacalein and wogonin was achieved via enzymatic deglycosylation of bacalin and wogonoside.

  6. Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants.

    Science.gov (United States)

    Dalla, Safaa; Dobler, Susanne

    2016-12-01

    Herbivorous insects and their adaptations against plant toxins provide striking opportunities to investigate the genetic basis of traits involved in coevolutionary interactions. Target site insensitivity to cardenolides has evolved convergently across six orders of insects, involving identical substitutions in the Na,K-ATPase gene and repeated convergent gene duplications. The large milkweed bug, Oncopeltus fasciatus, has three copies of the Na,K-ATPase α-subunit gene that bear differing numbers of amino acid substitutions in the binding pocket for cardenolides. To analyze the effect of these substitutions on cardenolide resistance and to infer possible trade-offs in gene function, we expressed the cardenolide-sensitive Na,K-ATPase of Drosophila melanogaster in vitro and introduced four distinct combinations of substitutions observed in the three gene copies of O. fasciatus. With an increasing number of substitutions, the sensitivity of the Na,K-ATPase to a standard cardenolide decreased in a stepwise manner. At the same time, the enzyme's overall activity decreased significantly with increasing cardenolide resistance and only the least substituted mimic of the Na,K-ATPase α1C copy maintained activity similar to the wild-type enzyme. Our results suggest that the Na,K-ATPase copies in O. fasciatus have diverged in function, enabling specific adaptations to dietary cardenolides while maintaining the functionality of this critical ion carrier. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  7. Fuel prices, emission standards, and generation costs for coal vs natural gas power plants.

    Science.gov (United States)

    Pratson, Lincoln F; Haerer, Drew; Patiño-Echeverri, Dalia

    2013-05-07

    Low natural gas prices and stricter, federal emission regulations are promoting a shift away from coal power plants and toward natural gas plants as the lowest-cost means of generating electricity in the United States. By estimating the cost of electricity generation (COE) for 304 coal and 358 natural gas plants, we show that the economic viability of 9% of current coal capacity is challenged by low natural gas prices, while another 56% would be challenged by the stricter emission regulations. Under the current regulations, coal plants would again become the dominant least-cost generation option should the ratio of average natural gas to coal prices (NG2CP) rise to 1.8 (it was 1.42 in February 2012). If the more stringent emission standards are enforced, however, natural gas plants would remain cost competitive with a majority of coal plants for NG2CPs up to 4.3.

  8. Ecotoxicological effects of copper and selenium combined pollution on soil enzyme activities in planted and unplanted soils.

    Science.gov (United States)

    Hu, Bin; Liang, Dongli; Liu, Juanjuan; Xie, Junyu

    2013-04-01

    The present study explored the joint effects of Cu and Se pollution mechanisms on soil enzymes to provide references for the phytoremediation of contaminated areas and agricultural environmental protection. Pot experiments and laboratory analyses were carried out to study the individual and combined influences of Cu and Se on soil enzyme activities. The activities of four soil enzymes (urease, catalase, alkaline phosphatase, and nitrate reductase) were chosen. All soil enzyme activities tested were inhibited by Cu and Se pollution, either individually or combined, in varying degrees, following the order nitrate reductase>urease>catalase>alkaline phosphatase. Growing plants stimulated soil enzyme activity in a similar trend compared with treatments without plants. The joint effects of Cu and Se on catalase activity showed synergism at low concentrations and antagonism at high concentrations, whereas the opposite was observed for urease activity. However, nitrate reductase activity showed synergism both with and without plant treatments. The half maximal effective concentration (EC50) of exchangeable fractions had a similar trend with the EC50 of total content and was lower than that of total content. The EC50 values of nitrate reductase and urease activities were significantly lower for both Se and Cu (p<0.05), which indicated that they were more sensitive than the other two enzymes.

  9. Metal ion binding and function in natural and artificial small RNA enzymes from a structural perspective.

    Science.gov (United States)

    Wedekind, Joseph E

    2011-01-01

    Ribozymes are often perceived as part of an antiquated catalytic arsenal hearkening back to a pre-biotic RNA World that was eventually supplanted by proteins. However, recent genome-wide searches have revealed a plethora of new catalytic RNA motifs that appear to be variations on well-known themes. This suggests that ribozymes have continued to evolve in order to fulfill specific, RNA-essential biological niches. Although such ribozymes are small and catalyze one-step phosphodiester-bond scission reactions, ongoing structure and function analyses at the lab bench have demonstrated that RNA has the capacity for a diverse number of reactions such as carbon-carbon bond formation, and tRNA aminoacylation. Here we describe the fundamental structure and metal binding properties of four naturally occurring RNA enzymes: the hammerhead, hairpin, hepatitis delta virus, and glmS metabolite sensing ribozyme. In addition, we discuss the fold and ion coordination of three artificial ribozymes developed to probe the boundaries of RNA catalysis; these include the leadzyme, the flexizyme, and the Diels-Alder ribozyme. Our approach is to relate structure to function with the knowledge of ideal metal-ion coordination geometry that we have derived herein from surveys of high-resolution small molecule structures. An emergent theme is that natural and artificial ribozymes that catalyze single-step reactions often possess a pre-formed active site. Multivalent ions facilitate RNA active site formation, but can also provide Lewis acid functionality that is necessary for catalysis. When metal ion binding isn't possible, ribozymes make due by ionizing their bases, or by recruiting cofactors that augment their chemical functionality.

  10. Oxidative enzymes activity in sugarcane juice as a function of the planting system

    Directory of Open Access Journals (Sweden)

    Tadeu Alcides Marques

    2013-03-01

    Full Text Available In Brazil, the largest producer of sugarcane in the world, the industrial process transforms this crop into ethanol and/or granulated sugar. Some cultivars exhibit enzymatic browning in the extracted sugarcane juice at levels harmful to the manufacturing process of white granulated sugar. The objective of this study was to assess the effect of sugarcane straw used as soil coverage, the use of different planting systems, and treatments with hydrogel polymer on enzymatic activity. The cultivar RB 86 7515 was sampled for 8 months; the first sample was obtained by cutting the upper portion of the stalk at the internode, which was taken to the laboratory for determination of the enzymatic activity of polyphenoloxidase (PPO and peroxidase (POD. The soil coverage with different forms of straw as well as the planting systems did not change the enzymatic activity of polyphenoloxidase (PPO and peroxidase (POD. The polyphenoloxidase (PPO activity increased with the use of a polymer due to increased polyphenoloxidase (PPO activity in the groove system. The enzymes studied showed changes in activity during the experimental period. The production of sugar at the end of the season (August to November avoids the periods of highest enzymatic activity.

  11. Plant-mediated effects on extracellular enzyme activities in distinct soil aggregate size classes in field

    Science.gov (United States)

    Kumar, Amit; Dorodnikov, Maxim; Splettstößer, Thomas; Kuzyakov, Yakov; Pausch, Johanna

    2017-04-01

    Soil aggregation and microbial activities within the aggregates are important factors regulating soil carbon (C) turnover. A reliable and sensitive proxy for microbial activity is activity of extracellular enzymes (EEA). In the present study, effects of soil aggregates on EEA were investigated under three maize plant densities (Low, Normal, and High). Bulk soil was fractionated into three aggregate size classes (>2000 µm large macroaggregates; 2000-250 µm small macroaggregates; moisture sieving. Microbial biomass and EEA (β-1,4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG), L-leucine aminopeptidase (LAP) and acid phosphatase (acP)) catalyzing soil organic matter (SOM) decomposition were measured in rooted soil of maize and soil from bare fallow. Microbial biomass C (Cmic) decreased with decreasing aggregate size classes. Potential and specific EEA (per unit of Cmic) increased from macro- to microaggregates. In comparison with bare fallow soil, specific EEA of microaggregates in rooted soil was higher by up to 73%, 31%, 26%, and 92% for BG, NAG, acP and LAP, respectively. Moreover, high plant density decreased macroaggregates by 9% compared to bare fallow. Enhanced EEA in three aggregate size classes demonstrated activation of microorganisms by roots. Strong EEA in microaggregates can be explained by microaggregates' localization within the soil. Originally adhering to surfaces of macroaggregates, microaggregates were preferentially exposed to C substrates and nutrients, thereby promoting microbial activity.

  12. Enzyme analysis for Pompe disease in leukocytes; superior results with natural substrate compared with artificial substrates.

    Science.gov (United States)

    van Diggelen, O P; Oemardien, L F; van der Beek, N A M E; Kroos, M A; Wind, H K; Voznyi, Y V; Burke, D; Jackson, M; Winchester, B G; Reuser, A J J

    2009-06-01

    Enzyme analysis for Pompe disease in leukocytes has been greatly improved by the introduction of acarbose, a powerful inhibitor of interfering alpha-glucosidases, which are present in granulocytes but not in lymphocytes. Here we show that the application of acarbose in the enzymatic assay employing the artificial substrate 4-methylumbelliferyl-alpha-D: -glucoside (MU-alphaGlc) is insufficient to clearly distinguish patients from healthy individuals in all cases. Also, the ratios of the activities without/with acarbose only marginally discriminated Pompe patients and healthy individuals. By contrast, when the natural substrate glycogen is used, the activity in leukocytes from patients (n = 82) with Pompe disease is at most 17% of the lowest control value. The use of artificial substrate in an assay with isolated lymphocytes instead of total leukocytes is a poor alternative as blood samples older than one day invariably yield lymphocyte preparations that are contaminated with granulocytes. To diagnose Pompe disease in leukocytes we recommend the use of glycogen as substrate in the presence of acarbose. This assay unequivocally excludes Pompe disease. To also exclude pseudo-deficiency of acid alpha-glucosidase caused by the sequence change c.271G>A (p.D91N or GAA2; homozygosity in approximately 1:1000 caucasians), a second assay employing MU-alphaGlc substrate plus acarbose or DNA analysis is required.

  13. Covalent attachment of the plant natural product naringenin to small glass and ceramic beads

    Directory of Open Access Journals (Sweden)

    Grotewold Erich

    2005-10-01

    Full Text Available Abstract Background Natural products have numerous medicinal applications and play important roles in the biology of the organisms that accumulate them. Few methods are currently available for identifying proteins that bind to small molecules, therefore the discovery of cellular targets for natural products with pharmacological activity continues to pose a significant challenge in drug validation. Similarly, the identification of enzymes that participate in the biosynthesis or modification of natural products remains a formidable bottleneck for metabolic engineering. Flavonoids are one large group of natural products with a diverse number of functions in plants and in human health. The coupling of flavonoids to small ceramic and glass beads provides a first step in the development of high-throughput, solid-support base approaches to screen complex libraries to identify proteins that bind natural products. Results The utilization of small glass and ceramic beads as solid supports for the coupling of small molecules was explored. Initial characterization of the beads indicated uniform and high capacity loading of amino groups. Once the beads were deemed adequate for the linking of small molecules by the coupling of NHS-fluorescein followed by microscopy, chemical hydrolysis and fluorometry, the flavonoid naringenin was modified with 1,4-dibromobutane, followed by the attachment of aminopropyltriethoxysilane. After NMR structural confirmation, the resulting 7-(4-(3-(triethoxysilylpropylaminobutoxy naringenin was attached to the ceramic beads. Conclusion Our results demonstrate that ceramic and glass beads provide convenient solid supports for the efficient and facile coupling of small molecules. We succeeded in generating naringenin-coupled ceramic and glass beads. We also developed a convenient series of steps that can be applied for the solid-support coupling of other related flavonoids. The availability of solid-support coupled naringenin opens

  14. An Optimized Microplate Assay System for Quantitative Evaluation of Plant Cell Wall Degrading Enzyme Activity of Fungal Culture Extracts

    Science.gov (United States)

    Developing enzyme cocktails for cellulosic biomass hydrolysis complementary to current cellulase systems is a critical step needed for economically viable biofuels production. Recent genomic analysis indicates that some plant pathogenic fungi are likely a largely untapped resource in which to prospe...

  15. Effects of antimony and arsenic on antioxidant enzyme activities of two steppic plant species in an old antimony mining area.

    Science.gov (United States)

    Benhamdi, Asma; Bentellis, Alima; Rached, Oualida; Du Laing, Gijs; Mechakra, Aicha

    2014-04-01

    The present work was undertaken to determine strategies and antioxidant enzyme activities involved in the adaptation of two wild steppic plants (Hedysarum pallidum Desf. and Lygeum spartum L.) to the toxic environment of the abandoned antimony mining area of Djebel Hamimat (Algeria). For this purpose, soils and plants were collected in different zones coinciding with a Sb and As concentrations gradient in the soil. Antimony (Sb) and arsenic (As) were analyzed by ICP-OES in the soils and the aboveground parts and roots of the plants. Malondialdehyde (MDA) and antioxidant enzyme activities were measured by spectrometry. Results show levels of Sb and As exceptionally high in most soil and plant samples. The two species accumulate differently Sb and As in their above and belowground parts. MDA levels, in the two parts of both species, increase significantly with increasing soil Sb and As concentrations, but they are significantly higher in H. pallidum than in L. spartum. The activities of antioxidant enzymes differ significantly according to the soil metalloid concentrations, the plant species considered and the plant part. Apart from superoxide dismutase (SOD) whose activity is, overall, higher in H. pallidum than in L. spartum, the activities of all the other enzymes studied (glutathione S-transferase (GST), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX)) are generally higher in L. spartum than in H. pallidum. For both species, APX and GST are overall more active in the upper parts than in the roots, while it is the reverse for SOD and CAT. POD is more active in the upper parts than in the roots of L. spartum and the reverse applies to H. pallidum. It appears that the two studied plant species use different tolerance strategies to protect themselves against elevated As and Sb concentrations.

  16. Responses of antioxidant enzymes to cold and high light are not correlated to freezing tolerance in natural accessions of Arabidopsis thaliana.

    Science.gov (United States)

    Distelbarth, H; Nägele, T; Heyer, A G

    2013-11-01

    Low temperatures and high light cause imbalances in primary and secondary reactions of photosynthesis, and thus can result in oxidative stress. Plants employ a range of low-molecular weight antioxidants and antioxidant enzymes to prevent oxidative damage, and antioxidant defence is considered an important component of stress tolerance. To figure out whether oxidative stress and antioxidant defence are key factors defining the different cold acclimation capacities of natural accessions of the model plant Arabidopsis thaliana, we investigated hydrogen peroxide (H2 O2 ) production, antioxidant enzyme activity and lipid peroxidation during a time course of cold treatment and exposure to high light in four differentially cold-tolerant natural accessions of Arabidopsis (C24, Nd, Rsch, Te) that span the European distribution range of the species. All accessions except Rsch (from Russia) had elevated H2 O2 in the cold, indicating that production of reactive oxygen species is part of the cold response in Arabidopsis. Glutathione reductase activity increased in all but Rsch, while ascorbate peroxidase and superoxide dismutase were unchanged and catalase decreased in all but Rsch. Under high light, the Scandinavian accession Te had elevated levels of H2 O2 . Te appeared most sensitive to oxidative stress, having higher malondialdehyde (MDA) levels in the cold and under high light, while only high light caused elevated MDA in the other accessions. Although the most freezing-tolerant, Te had the highest sensitivity to oxidative stress. No correlation was found between freezing tolerance and activity of antioxidant enzymes in the four accessions investigated, arguing against a key role for antioxidant defence in the differential cold acclimation capacities of Arabidopsis accessions. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. The right ventricle in Fabry disease: natural history and impact of enzyme replacement therapy.

    Science.gov (United States)

    Niemann, Markus; Breunig, Frank; Beer, Meinrad; Herrmann, Sebastian; Strotmann, Jörg; Hu, Kai; Emmert, Andrea; Voelker, Wolfram; Ertl, Georg; Wanner, Christoph; Weidemann, Frank

    2010-12-01

    Storage of globotriaosylceramides is present in the left and right ventricles of patients with Fabry disease. Improvement of left ventricular morphology and function during enzyme replacement therapy (ERT) has previously been reported. To analyse the effects of long term ERT on right ventricular morphology and function. This was a prospective follow-up of 75 genetically confirmed consecutive Fabry patients for 3.1±1.8 years. According to treatment guidelines the natural history was followed in 18 patients, whereas 57 patients received ERT. Standard echocardiography, strain rate imaging for regional deformation of the right and left ventricle, and magnetic resonance tomography with late enhancement (LE) imaging for the detection of fibrosis were all performed at yearly intervals. Right ventricular hypertrophy was evident in 53 patients (71%) at baseline. A significant positive correlation was found between left and right ventricular wall thickness (r=0.76; pright ventricle. Patients with LE in the left ventricle presented with the lowest right ventricular deformation properties. In contrast to the left ventricle, there was no change in right ventricular wall thickness (baseline 6.9±1.6 mm vs follow-up 6.7±1.5 mm; p=0.44) or systolic strain rate (2.2±0.7/s vs 2.1±0.8/s; p=0.31) during follow-up with ERT. The degree of right ventricular involvement in Fabry disease is related to the left ventricular cardiomyopathy stage. ERT seems to have no direct impact on right ventricular morphology and function.

  18. Taliglucerase alfa: an enzyme replacement therapy using plant cell expression technology.

    Science.gov (United States)

    Grabowski, Gregory A; Golembo, Myriam; Shaaltiel, Yoseph

    2014-05-01

    Gaucher disease (GD) is a rare, genetic lysosomal storage disorder caused by functional defects of acid β-glucosidase that results in multiple organ dysfunction. Glycosylation of recombinant acid human β-glucosidase and exposure of terminal mannose residues are critical to the success of enzyme replacement therapy (ERT) for the treatment of visceral and hematologic manifestations in GD. Three commercially available ERT products for treatment of GD type 1 (GD1) include imiglucerase, velaglucerase alfa, and taliglucerase alfa. Imiglucerase and velaglucerase alfa are produced in different mammalian cell systems and require production glycosylation modifications to expose terminal α-mannose residues, which are needed for mannose receptor-mediated uptake by target macrophages. Such modifications add to production costs. Taliglucerase alfa is a plant cell-expressed acid β-glucosidase approved in the United States and other countries for ERT in adults with GD1. A plant-based expression system, using carrot root cell cultures, was developed for production of taliglucerase alfa and does not require additional processing for postproduction glycosidic modifications. Clinical trials have demonstrated that taliglucerase alfa is efficacious, with a well-established safety profile in adult, ERT-naïve patients with symptomatic GD1, and for such patients previously treated with imiglucerase. These included significant improvements in organomegaly and hematologic parameters as early as 6months, and maintenance of achieved therapeutic values in previously treated patients. Ongoing clinical trials will further characterize the long-term efficacy and safety of taliglucerase alfa in more diverse patient populations, and may help to guide clinical decisions for achieving optimal outcomes for patients with GD1.

  19. Estimation of Nitrogenase Enzyme Activities and Plant Growth of Legume and Non-legume Inoculated with Diazotrophic Bacteria

    Directory of Open Access Journals (Sweden)

    Salwani S.

    2012-06-01

    Full Text Available Biological Nitrogen Fixation (BNF process benefits the agriculture sector especially for reducing cost of nitrogenfertilizer. In the process, the diazotrophs convert N2 into ammonia (NH3 which is useable by plants. The BNF process iscatalysed by nitrogenase enzyme that involved protons and electrons together with evolution of H2 therefore, theassessment of N2 fixation is also available via H2 production and electron allocation analysis. Thus, the aims of thisexperiment were to estimate the nitrogenase enzyme activities and observe the influence of diazothrophs on growth oflegume (soybean and non legume (rice plants. Host plants were inoculated with respective inocula; Bradyrhizobiumjaponicum (strain 532C for soybean while Azospirillum brasilense (Sp7 and locally isolated diazotroph (isolate 5 forrice. At harvest, the plants were observed for plant growth parameters, H2 evolution, N2 fixation and electron allocationcoefficient (EAC values. The experiment recorded N2 fixation activities of inoculated soybean plants at 141.2 μmol N2 h-1g-1 dry weight nodule, and the evolution of H2 at 144.4 μmol H2 h-1 g-1 dry weight nodule. The electron allocationcoefficient (EAC of soybean was recorded at 0.982. For inoculated rice plants, none of the observations was successfully recorded. However, results for chlorophyll contents and plant dry weight of both plants inoculated with respective inocula were similar to the control treatments supplied with full nitrogen fertilization (+N. The experiment clearly showed that inoculation of diazotrophic bacteria could enhance growth of the host plants similar to plants treated with nitrogenous fertilizer due to efficient N2 fixation process

  20. Local CHP Plants between the Natural Gas and Electricity Systems

    DEFF Research Database (Denmark)

    Bregnbæk, Lars; Schaumburg-Müller, Camilla

    2005-01-01

    that are expected to be in force in Denmark during 2005, where a large part of the local CHP plants will change from being paid for electricity production according to a feed-in tariff, to a situation where the electricity is to be sold on market conditions. The results will highlight the CHP plant as the link...

  1. Plant performance: a physiological and genetic analysis using Arabidopsis thaliana natural variation

    NARCIS (Netherlands)

    El-Lithy, M.E.M.

    2005-01-01

    Plant performance implies complex traits, controlled by a large set of genes and affected by the environment. In this thesis we have tried to take the first steps in unravelling the genes controlling plant performance using naturally occurring accessions (ecotypes) of the model plant Arabidopsis

  2. Redox enzymes in the plant plasma membrane and their possible roles

    DEFF Research Database (Denmark)

    Berczi, A.; Møller, I.M.

    2000-01-01

    Purified plasma membrane (PM) vesicles from higher plants contain redox proteins with low-molecular-mass prosthetic groups such as flavins (both FMN and FAD), hemes, metals (Cu, Fe and Mn), thiol groups and possibly naphthoquinone (vitamin K-1), all of which are likely to participate in redox.......1.1.37) is localized on the inner side of the PM. Several NAD(P)H-quinone oxidoreductases have been purified from the cytocolic surface of the PM, but their function is still unknown. Different forms of nitrate reductase (EC 1.6.6.1-3) are found attached to, as well as anchored in, the PM where they may act...... as a nitrate sensor and/or contribute to blue-light perception, although both functions are speculative. Ferric-chelate-reducing enzymes (EC 1.6.99.13) are localized and partially characterized on the inner surface of the PM but they may participate only in the reduction of ferric-chelates in the cytosol. Very...

  3. [Research progress of chemistry and anti-cancer activities of natural products from Chinese Garcinia plants].

    Science.gov (United States)

    Fu, Wen-Wei; Tan, Hong-Sheng; Xu, Hong-Xi

    2014-02-01

    Garcinia plants are one of the rich sources of natural xanthones and benzophenones which have attracted a great deal of attention from the scientists in the fields of chemistry and pharmacology. Recently, many structurally unique constituents with various bioactivities, especially anti-tumor activity, have been isolated from Garcinia plants. This concise review focused on the anti-cancer activity natural products isolated from Chinese Garcinia plants, and the research finding by authors and collaborators over the past several years were cited.

  4. Bioprospecting plants for natural antioxidants:An overview

    Institute of Scientific and Technical Information of China (English)

    Huma Qureshi; Muhammad Arshad; Wajiha Seerat; Faryal Kabir; Sammer Fatima

    2016-01-01

    Reactive oxygen species damage cellular proteins and lipids or form DNA adducts when present in high concentration that promotes carcinogenic activities. Plants have been the primary therapy for such ailments since ancient times. This paper reviews some medicinal plants having antioxidant activities useful for healing cancer, cardiovascular diseases and neuro-protection. A brief overview of the use of medicinal plants and their main constituents effective against reactive oxygen species-based diseases are presented. This overview will attract the interest of investigators aiming at the design of novel therapeutic approaches for the treatment of various reactive oxygen species-based conditions.

  5. 40 CFR 174.525 - E. coli B-D-glucuronidase enzyme as a plant-incorporated protectant inert ingredient; exemption...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false E. coli B-D-glucuronidase enzyme as a... E. coli B-D-glucuronidase enzyme as a plant-incorporated protectant inert ingredient; exemption from the requirement of a tolerance. Residues of E. coli B-D-glucuronidase enzyme are exempt from...

  6. Soil microflora and enzyme activities in rhizosphere of Transgenic Bt cotton hybrid under different intercropping systems and plant protection schedules

    Science.gov (United States)

    Biradar, D. P.; Alagawadi, A. R.; Basavanneppa, M. A.; Udikeri, S. S.

    2012-04-01

    Field experiments were conducted over three rainy seasons of 2005-06 to 2007-08 on a Vertisol at Dharwad, Karnataka, India to study the effect of intercropping and plant protection schedules on productivity, soil microflora and enzyme activities in the rhizosphere of transgenic Bt cotton hybrid. The experiment consisted of four intercropping systems namely, Bt cotton + okra, Bt cotton + chilli, Bt cotton + onion + chilli and Bt cotton + redgram with four plant protection schedules (zero protection, protection for Bt cotton, protection for intercrop and protection for both crops). Observations on microbial populations and enzyme activities were recorded at 45, 90, 135 and 185 (at harvest) days after sowing (DAS). Averaged over years, Bt cotton + okra intercropping had significantly higher total productivity than Bt cotton + chilli and Bt cotton + redgram intercropping system and was similar to Bt cotton + chilli + onion intercropping system. With respect to plant protection schedules for bollworms, protection for both cotton and intercrops recorded significantly higher yield than the rest of the treatments. Population of total bacteria, fungi, actinomycetes, P-solubilizers, free-living N2 fixers as well as urease, phosphatase and dehydrogenase enzyme activities increased up to 135 days of crop growth followed by a decline. Among the intercropping systems, Bt cotton + chilli recorded significantly higher population of microorganisms and enzyme activities than other cropping systems. While Bt cotton with okra as intercrop recorded the least population of total bacteria and free-living N2 fixers as well as urease activity. Intercropping with redgram resulted in the least population of actinomycetes, fungi and P-solubilizers, whereas Bt cotton with chilli and onion recorded least activities of dehydrogenase and phosphatase. Among the plant protection schedules, zero protection recorded maximum population of microorganisms and enzyme activities. This was followed by the

  7. Natural selection on plant resistance to herbivores in the native and introduced range

    OpenAIRE

    2015-01-01

    When plants are introduced into new regions, the absence of their co-evolved natural enemies can result in lower levels of attack. As a consequence of this reduction in enemy pressure, plant performance may increase and selection for resistance to enemies may decrease. In the present study, we compared leaf damage, plant size and leaf trichome density, as well as the direction and magnitude of selection on resistance and plant size between non-native (Spain) and native (Mexico) populations of...

  8. Antimicrobial nature and use of some medicinal plants in Nigeria

    African Journals Online (AJOL)

    SERVER

    2008-03-04

    Mar 4, 2008 ... some genetically modified plants or living things in gene- ral can enhance ..... engineering as part of modern biotechnology that helps to enhance this kind of ... Programmes. Prepared by W.H.O. Division of Malaria and other.

  9. An optimized microplate assay system for quantitative evaluation of plant cell wall-degrading enzyme activity of fungal culture extracts.

    Science.gov (United States)

    King, Brian C; Donnelly, Marie K; Bergstrom, Gary C; Walker, Larry P; Gibson, Donna M

    2009-03-01

    Developing enzyme cocktails for cellulosic biomass hydrolysis complementary to current cellulase systems is a critical step needed for economically viable biofuels production. Recent genomic analysis indicates that some plant pathogenic fungi are likely a largely untapped resource in which to prospect for novel hydrolytic enzymes for biomass conversion. In order to develop high throughput screening assays for enzyme bioprospecting, a standardized microplate assay was developed for rapid analysis of polysaccharide hydrolysis by fungal extracts, incorporating biomass substrates. Fungi were grown for 10 days on cellulose- or switchgrass-containing media to produce enzyme extracts for analysis. Reducing sugar released from filter paper, Avicel, corn stalk, switchgrass, carboxymethylcellulose, and arabinoxylan was quantified using a miniaturized colorimetric assay based on 3,5-dinitrosalicylic acid. Significant interactions were identified among fungal species, growth media composition, assay substrate, and temperature. Within a small sampling of plant pathogenic fungi, some extracts had crude activities comparable to or greater than T. reesei, particularly when assayed at lower temperatures and on biomass substrates. This microplate assay system should prove useful for high-throughput bioprospecting for new sources of novel enzymes for biofuel production.

  10. Influence of arbuscular mycorrhiza on lipid peroxidation and antioxidant enzyme activity of maize plants under temperature stress.

    Science.gov (United States)

    Zhu, Xiancan; Song, Fengbin; Xu, Hongwen

    2010-06-01

    The influence of the arbuscular mycorrhizal (AM) fungus, Glomus etunicatum, on characteristics of growth, membrane lipid peroxidation, osmotic adjustment, and activity of antioxidant enzymes in leaves and roots of maize (Zea mays L.) plants was studied in pot culture under temperature stress. The maize plants were placed in a sand and soil mixture under normal temperature for 6 weeks and then exposed to five different temperature treatments (5 degrees C, 15 degrees C, 25 degrees C, 35 degrees C, and 40 degrees C) for 1 week. AM symbiosis decreased membrane relative permeability and malondialdehyde content in leaves and roots. The contents of soluble sugar content and proline in roots were higher, but leaf proline content was lower in mycorrhizal than nonmycorrhizal plants. AM colonization increased the activities of superoxide dismutase, catalase, and peroxidase in leaves and roots. The results indicate that the AM fungus is capable of alleviating the damage caused by temperature stress on maize plants by reducing membrane lipid peroxidation and membrane permeability and increasing the accumulation of osmotic adjustment compounds and antioxidant enzyme activity. Consequently, arbuscular mycorrhiza formation highly enhanced the extreme temperature tolerance of maize plant, which increased host biomass and promoted plant growth.

  11. Host-Pathogen Interactions: VII. Plant Pathogens Secrete Proteins which Inhibit Enzymes of the Host Capable of Attacking the Pathogen.

    Science.gov (United States)

    Albersheim, P; Valent, B S

    1974-05-01

    The results presented demonstrate that microbial pathogens of plants have the ability to secrete proteins which effectively inhibit an enzyme synthesized by the host; an enzyme whose substrate is a constituent of the cell wall of the pathogen. The system in which this was discovered is the anthracnose-causing fungal pathogen (Colletotrichum lindemuthianum) and its host, the French bean (Phaseolus vulgaris). An endo-beta-1, 3-glucanase present in the bean leaves is specifically inhibited by a protein secreted by C. lindemuthianum. The cell walls of C. lindemuthianum are shown to be composed largely of a 1, 3-glucan.

  12. Multi-Target Screening and Experimental Validation of Natural Products from Selaginella Plants against Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Yin-Hua Deng

    2017-08-01

    Full Text Available Alzheimer's disease (AD is a progressive and irreversible neurodegenerative disorder which is considered to be the most common cause of dementia. It has a greater impact not only on the learning and memory disturbances but also on social and economy. Currently, there are mainly single-target drugs for AD treatment but the complexity and multiple etiologies of AD make them difficult to obtain desirable therapeutic effects. Therefore, the choice of multi-target drugs will be a potential effective strategy inAD treatment. To find multi-target active ingredients for AD treatment from Selaginella plants, we firstly explored the behaviors effects on AD mice of total extracts (TE from Selaginella doederleinii on by Morris water maze test and found that TE has a remarkable improvement on learning and memory function for AD mice. And then, multi-target SAR models associated with AD-related proteins were built based on Random Forest (RF and different descriptors to preliminarily screen potential active ingredients from Selaginella. Considering the prediction outputs and the quantity of existing compounds in our laboratory, 13 compounds were chosen to carry out the in vitro enzyme inhibitory experiments and 4 compounds with BACE1/MAO-B dual inhibitory activity were determined. Finally, the molecular docking was applied to verify the prediction results and enzyme inhibitory experiments. Based on these study and validation processes, we explored a new strategy to improve the efficiency of active ingredients screening based on trace amount of natural product and numbers of targets and found some multi-target compounds with biological activity for the development of novel drugs for AD treatment.

  13. Natural toxins that affect plant amino acid metabolism

    Science.gov (United States)

    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...

  14. Climate change may threaten habitat suitability of threatened plant species within Chinese nature reserves.

    Science.gov (United States)

    Wang, Chunjing; Liu, Chengzhu; Wan, Jizhong; Zhang, Zhixiang

    2016-01-01

    Climate change has the potential to alter the distributions of threatened plant species, and may therefore diminish the capacity of nature reserves to protect threatened plant species. Chinese nature reserves contain a rich diversity of plant species that are at risk of becoming more threatened by climate change. Hence, it is urgent to identify the extent to which future climate change may compromise the suitability of threatened plant species habitats within Chinese nature reserves. Here, we modelled the climate suitability of 82 threatened plant species within 168 nature reserves across climate change scenarios. We used Maxent modelling based on species occurrence localities and evaluated climate change impacts using the magnitude of change in climate suitability and the degree of overlap between current and future climatically suitable habitats. There was a significant relationship between overlap with current and future climate suitability of all threatened plant species habitats and the magnitude of changes in climate suitability. Our projections estimate that the climate suitability of more than 60 threatened plant species will decrease and that climate change threatens the habitat suitability of plant species in more than 130 nature reserves under the low, medium, and high greenhouse gas concentration scenarios by both 2050s and 2080s. Furthermore, future climate change may substantially threaten tree plant species through changes in annual mean temperature. These results indicate that climate change may threaten plant species that occur within Chinese nature reserves. Therefore, we suggest that climate change projections should be integrated into the conservation and management of threatened plant species within nature reserves.

  15. Development of an enzyme-linked immunosorbent assay for the veratrum plant teratogens: cyclopamine and jervine.

    Science.gov (United States)

    Lee, Stephen T; Panter, Kip E; Gaffield, William; Stegelmeier, Bryan L

    2003-01-29

    Veratrum californicum was responsible for large losses of sheep grazing high mountain ranges in central Idaho in the 1950s. Veratrum induces various birth defects including the cyclopic-type craniofacial defect (monkey-faced lambs) that is specifically induced in lambs after pregnant ewes grazed the plant on the 14th day of gestation. The steroidal alkaloids cyclopamine (1) and jervine (2) were isolated from Veratrum and shown to be primarily responsible for the malformations. Cyclopamine (1) and jervine (2) are potent teratogens that inhibit Sonic hedgehog (Shh) signaling during gastrulation-stage embryonic development, producing cyclopia and holoprosencephaly. Although losses to the sheep industry from Veratrum are now relatively infrequent, occasional incidents of toxicoses and craniofacial malformations are still reported in sheep and other species. However, the benefits to biomedical research using cyclopamine (1) as a tool to study human diseases have greatly expanded. A competitive inhibition enzyme-linked immunosorbent assay (ELISA) to detect and measure cyclopamine (1) and jervine (2) was developed using polyclonal antibodies produced in ewes. The limits of detection of the assay were 90.0 and 22.7 pg for cyclopamine (1) and jervine (2), respectively. This assay was used for the detection and measurement of cyclopamine (1) spiked into sheep blood. The simple extraction-ELISA methods developed in this study demonstrate the potential of using these techniques for the rapid screening of biological samples to detect the presence and concentration of cyclopamine (1) and jervine (2) and will be beneficial to pharmacological studies and livestock diagnostics.

  16. Penicillinase-based enzyme-linked immunosorbent assay for the detection of plant viruses.

    Science.gov (United States)

    Sudarshana, M R; Reddy, D V

    1989-10-01

    A penicillinase (PNC)-based, enzyme-linked immunosorbent assay (ELISA) was standardized to detect maize mosaic virus (MMV) in sorghum leaf extracts, peanut mottle virus (PMV) in pea leaf extracts, and tomato spotted wilt virus (TSWV) in peanut leaf extracts. Rabbit Fc-specific antibodies were conjugated with PNC by a single step glutaraldehyde bridge. Among several indicators tested, bromothymol blue (BTB) was found suitable for measuring PNC activity under simulated conditions. Two reagents, starch-iodine complex (SIC) and a mixed pH indicator, containing bromocresol purple and BTB (2:1) used earlier for the PNC-based ELISA, were compared with BTB for utilization in the PNC-based ELISA. SIC gave a slightly higher virus titre than BTB or the mixed pH indicator, but it often gave nonspecific reactions. Sodium or potassium salts of penicillin-G at 0.5-1.0 mg/ml and BTB at 0.2 mg/ml were found to be suitable as substrate-indicator mixture for PNC-based ELISA. The sensitivity of the PNC system was comparable to those of the alkaline phosphatase (ALP) and horseradish peroxidase (HRP) systems in detecting MMV, PMV, and TSWV. The PNC conjugate could be used at a greater dilution than those of the ALP and HRP conjugates and the BTB substrate mixture was stable for at least 3 weeks at 4 degrees C. Penicillin is readily available in developing countries, and at a substantially lower cost than p-nitrophenyl phosphate, the commonly used substrate for ALP in the plate ELISA. Thus the PNC-based ELISA provides a less expensive means for assaying plant viruses by ELISA.

  17. Effective use of heterologous hosts for characterization of biosynthetic enzymes allows production of natural products and promotes new natural product discovery.

    Science.gov (United States)

    Watanabe, Kenji

    2014-01-01

    In the past few years, there has been impressive progress in elucidating the mechanism of biosynthesis of various natural products accomplished through the use of genetic, molecular biological and biochemical techniques. Here, we present a comprehensive overview of the current results from our studies on fungal natural product biosynthetic enzymes, including nonribosomal peptide synthetase and polyketide synthase-nonribosomal peptide synthetase hybrid synthetase, as well as auxiliary enzymes, such as methyltransferases and oxygenases. Specifically, biosynthesis of the following compounds is described in detail: (i) Sch210972, potentially involving a Diels-Alder reaction that may be catalyzed by CghA, a functionally unknown protein identified by targeted gene disruption in the wild type fungus; (ii) chaetoglobosin A, formed via multi-step oxidations catalyzed by three redox enzymes, one flavin-containing monooxygenase and two cytochrome P450 oxygenases as characterized by in vivo biotransformation of relevant intermediates in our engineered Saccharomyces cerevisiae; (iii) (-)-ditryptophenaline, formed by a cytochrome P450, revealing the dimerization mechanism for the biosynthesis of diketopiperazine alkaloids; (iv) pseurotins, whose variations in the C- and O-methylations and the degree of oxidation are introduced combinatorially by multiple redox enzymes; and (v) spirotryprostatins, whose spiro-carbon moiety is formed by a flavin-containing monooxygenase or a cytochrome P450 as determined by heterologous de novo production of the biosynthetic intermediates and final products in Aspergillus niger. We close our discussion by summarizing some of the key techniques that have facilitated the discovery of new natural products, production of their analogs and identification of biosynthetic mechanisms in our study.

  18. Natural Antioxidants in Foods and Medicinal Plants: Extraction, Assessment and Resources

    Science.gov (United States)

    Xu, Dong-Ping; Li, Ya; Meng, Xiao; Zhou, Tong; Zhou, Yue; Zheng, Jie; Zhang, Jiao-Jiao; Li, Hua-Bin

    2017-01-01

    Natural antioxidants are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols and carotenoids, exhibit a wide range of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis and anticancer. The effective extraction and proper assessment of antioxidants from food and medicinal plants are crucial to explore the potential antioxidant sources and promote the application in functional foods, pharmaceuticals and food additives. The present paper provides comprehensive information on the green extraction technologies of natural antioxidants, assessment of antioxidant activity at chemical and cellular based levels and their main resources from food and medicinal plants. PMID:28067795

  19. Natural Antioxidants in Foods and Medicinal Plants: Extraction, Assessment and Resources.

    Science.gov (United States)

    Xu, Dong-Ping; Li, Ya; Meng, Xiao; Zhou, Tong; Zhou, Yue; Zheng, Jie; Zhang, Jiao-Jiao; Li, Hua-Bin

    2017-01-05

    Natural antioxidants are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols and carotenoids, exhibit a wide range of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis and anticancer. The effective extraction and proper assessment of antioxidants from food and medicinal plants are crucial to explore the potential antioxidant sources and promote the application in functional foods, pharmaceuticals and food additives. The present paper provides comprehensive information on the green extraction technologies of natural antioxidants, assessment of antioxidant activity at chemical and cellular based levels and their main resources from food and medicinal plants.

  20. Is natural background or radiation from nuclear power plants leukemogenic

    Energy Technology Data Exchange (ETDEWEB)

    Cronkite, E.P.

    1989-01-01

    The objective in this review is to provide some facts about normal hemopoietic cell proliferation relevant to leukemogenesis, physical, chemical, and biological facts about radiation effects with the hope that each person will be able to decide for themselves whether background radiation or emissions from nuclear power plants and facilities significantly add to the spontaneous leukemia incidence. 23 refs., 1 tab.

  1. Chlorine-containing natural compounds in higher plants

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1986-01-01

    More than 130 chlorine-containing compounds have been isolated from higher plants and ferns; about half are polyacetylenes, thiophenes and sesquiterpene lactones from the Asteraceae. A chlorinated chlorophyll may be an important part of photosystem 1. High biological activity is found in 4...

  2. 1-Deoxy-D-xylulose-5-phosphate synthase, a limiting enzyme for plastidic isoprenoid biosynthesis in plants.

    Science.gov (United States)

    Estévez, J M; Cantero, A; Reindl, A; Reichler, S; León, P

    2001-06-22

    The initial step of the plastidic 2C-methyl-D-erythritol 4-phosphate (MEP) pathway that produces isopentenyl diphosphate is catalyzed by 1-deoxy-d-xylulose-5-phosphate synthase. To investigate whether or not 1-deoxy-d-xylulose-5-phosphate synthase catalyzes a limiting step in the MEP pathway in plants, we produced transgenic Arabidopsis plants that over- or underexpress this enzyme. Compared with non-transgenic wild-type plants, the transgenic plants accumulate different levels of various isoprenoids such as chlorophylls, tocopherols, carotenoids, abscisic acid, and gibberellins. Phenotypically, the transgenic plants had slight alterations in growth and germination rates. Because the levels of several plastidic isoprenoids correlate with changes in 1-deoxy-D-xylulose-5-phosphate synthase levels, we conclude that this enzyme catalyzes one of the rate-limiting steps of the MEP biosynthetic pathway. Furthermore, since the product of the MEP pathway is isopentenyl diphosphate, our results suggest that in plastids the pool of isopentenyl diphosphate is limiting to isprenoid production.

  3. Long-term effects of engineered nanoparticles on enzyme activity and functional bacteria in wastewater treatment plants.

    Science.gov (United States)

    Zheng, Xiong; Huang, Haining; Su, Yinglong; Wei, Yuanyuan; Chen, Yinguang

    2015-01-01

    The pervasive use of engineered nanoparticles (NPs) in a wide range of fields raises concerns about their potential environmental impacts. Previous studies confirmed that some NPs had already entered wastewater treatment plants (WWTPs). Wastewater nutrient removal depends on the metabolisms of activated sludge bacteria and their related key enzymes. Therefore, this study compared the possible influences of Al2O3, SiO2, TiO2, and ZnO NPs on the key enzymes activities and microbial community structures involved in wastewater treatment facilities. It was found that long-term exposure to these NPs significantly affected the microbial communities and changed the relative abundances of key functional bacteria, such as ammonia-oxidizing bacteria. Also, the gene expressions and catalytic activities of essential enzymes, such as ammonia monooxygenase, nitrite oxidoreductase, nitrate reductase, and nitrite reductase, were decreased, which finally resulted in a lower efficiency of biological nitrogen removal.

  4. Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Rogowska-Wrzesinska, Adelina; Hoffmann, Daniel

    2014-01-01

    The mutualism between leaf-cutting ants and their fungal symbionts revolves around processing and inoculation of fresh leaf pulp in underground fungus gardens, mediated by ant fecal fluid deposited on the newly added plant substrate. As herbivorous feeding often implies that growth is nitrogen li...... fungi, consistent with previous indications of convergent evolution of decomposition enzymes in attine ant fungal symbionts and phytopathogenic fungi....

  5. Effects of supplemental enzymes on apparent nutrient digestibility in rainbow trout (Oncorhynchus mykiss) fed plant-based diets

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Hjermitslev, Niels Harthøj; Ekmann, Kim Schøn

    2010-01-01

    Exogenous enzymes are widely applied in feed for monogastric animals including pigs and poultry as a means to increase the nutritional value of viscous grains by reducing the anti-nutritional effects of primarily non-starch polysaccharides (NSPs). In comparison, there is very limited information ...... ingredients for fish. However, it also reinforces the complexity of using exogenous dietary enzymes and that more research is required to better understand the mechanisms of actions.......Exogenous enzymes are widely applied in feed for monogastric animals including pigs and poultry as a means to increase the nutritional value of viscous grains by reducing the anti-nutritional effects of primarily non-starch polysaccharides (NSPs). In comparison, there is very limited information...... on the effects of enzymes in fish feed apart from phytase. Phytase works by hydrolyzing phytic acid, and numerous studies have documented that phytase supplementation increases phosphorus availability in fish fed diets with high inclusion levels of plant proteins. Plant derived proteins are increasingly used...

  6. Monolignol ferulate conjugates are naturally incorporated into plant lignins.

    Science.gov (United States)

    Karlen, Steven D; Zhang, Chengcheng; Peck, Matthew L; Smith, Rebecca A; Padmakshan, Dharshana; Helmich, Kate E; Free, Heather C A; Lee, Seonghee; Smith, Bronwen G; Lu, Fachuang; Sedbrook, John C; Sibout, Richard; Grabber, John H; Runge, Troy M; Mysore, Kirankumar S; Harris, Philip J; Bartley, Laura E; Ralph, John

    2016-10-01

    Angiosperms represent most of the terrestrial plants and are the primary research focus for the conversion of biomass to liquid fuels and coproducts. Lignin limits our access to fibers and represents a large fraction of the chemical energy stored in plant cell walls. Recently, the incorporation of monolignol ferulates into lignin polymers was accomplished via the engineering of an exotic transferase into commercially relevant poplar. We report that various angiosperm species might have convergently evolved to natively produce lignins that incorporate monolignol ferulate conjugates. We show that this activity may be accomplished by a BAHD feruloyl-coenzyme A monolignol transferase, OsFMT1 (AT5), in rice and its orthologs in other monocots.

  7. Monolignol ferulate conjugates are naturally incorporated into plant lignins

    Science.gov (United States)

    Karlen, Steven D.; Zhang, Chengcheng; Peck, Matthew L.; Smith, Rebecca A.; Padmakshan, Dharshana; Helmich, Kate E.; Free, Heather C. A.; Lee, Seonghee; Smith, Bronwen G.; Lu, Fachuang; Sedbrook, John C.; Sibout, Richard; Grabber, John H.; Runge, Troy M.; Mysore, Kirankumar S.; Harris, Philip J.; Bartley, Laura E.; Ralph, John

    2016-01-01

    Angiosperms represent most of the terrestrial plants and are the primary research focus for the conversion of biomass to liquid fuels and coproducts. Lignin limits our access to fibers and represents a large fraction of the chemical energy stored in plant cell walls. Recently, the incorporation of monolignol ferulates into lignin polymers was accomplished via the engineering of an exotic transferase into commercially relevant poplar. We report that various angiosperm species might have convergently evolved to natively produce lignins that incorporate monolignol ferulate conjugates. We show that this activity may be accomplished by a BAHD feruloyl–coenzyme A monolignol transferase, OsFMT1 (AT5), in rice and its orthologs in other monocots. PMID:27757415

  8. Antibacterial Properties of Hemp and Other Natural Fibre Plants: A Review

    Directory of Open Access Journals (Sweden)

    Belas Ahmed Khan

    2014-03-01

    Full Text Available Intervention against pathogenic bacteria using natural plant material has a long history. Plant materials also have been widely used as fillers and/or reinforcers in polymer composites. Some natural fibre plants, such as hemp, are regarded to possess antibacterial activity against a wide range of pathogenic bacteria. Innovative applications can be explored if they are incorporated in polymer composites. This review aims to compile the relevant investigations on antibacterial activity of hemp and other fibre plants such as jute, flax, kenaf, sisal, and bamboo. The antibacterial character might be contributed from cannabinoids, alkaloids, other bioactive compounds, or phenolic compounds of lignin. This review is intended to encourage utilization of hemp and other natural fibre plants in value-added diversified products. Some potential applications are also discussed.

  9. The study of distribution characteristics of vascular and naturalized plants in Dokdo, South Korea

    Directory of Open Access Journals (Sweden)

    Su-Young Jung

    2014-06-01

    Full Text Available This study was performed to investigate the distribution of vascular plants and the characteristics of naturalized plants in Dokdo Island, South Korea. The survey was conducted a total of 5 times from June 2012 to September 2013. The number of plants confirmed in this study was 60 taxa in total: 29 families, 49 genera, 55 species, 2 subspecies and 3 varieties. To classify them by regional groups, 53 taxa were confirmed in the Dongdo and 38 taxa were confirmed in the Seodo. Among them, the distribution of Stellaria neglecta Weihe and Puccinellia nipponica Ohwi was first discovered in this study. The naturalized plants distributed in Dokdo was 7 taxa: Chenopodium album L., Sonchus asper (L. Hill, Sonchus oleraceus L., Ipomoea purpurea Roth, Brassica juncea (L. Czern., etc. Overall, concerns over the naturalized plants in Dokdo are high regardless of the scale of their distribution and the appearance frequency.

  10. Plant MicroRNAs-Novel Players in Natural Medicine?

    Science.gov (United States)

    Lukasik, Anna; Zielenkiewicz, Piotr

    2016-12-22

    MicroRNAs (miRNAs) represent a class of small non-coding RNAs that act as efficient gene expression regulators and thus play many important roles in living organisms. Due to their involvement in several known human pathological and pathogenic states, miRNA molecules have become an important issue in medicine and gained the attention of scientists from the pharmaceutical industry. In recent few years, a growing number of studies have provided evidence that miRNAs may be transferred from one species to another and regulate gene expression in the recipients' cells. The most intriguing results revealed that stable miRNAs derived from food plants may enter the mammals' circulatory system and, after reaching the target, inhibit the production of specific mammalian protein. Part of the scientific community has perceived this as an attractive hypothesis that may provide a foundation for novel therapeutic approaches. In turn, others are convinced about the "false positive" effect of performed experiments from which the mentioned results were achieved. In this article, we review the recent literature that provides evidence (from both fronts) of dietary, plant miRNA uptake and functionality in various consumers. Additionally, we discuss possible miRNA transport mechanisms from plant food sources to human cells.

  11. Preparation of Antioxidant Enzymatic Hydrolysates from Honeybee-Collected Pollen Using Plant Enzymes

    Directory of Open Access Journals (Sweden)

    Margarita D. Marinova

    2010-01-01

    Full Text Available Enzymatic hydrolysates of honeybee-collected pollen were prepared using food-grade proteinase and aminopeptidases entirely of plant origin. Bromelain from pineapple stem was applied (8 mAU/g substrate in the first hydrolysis stage. Aminopeptidase (0.05 U/g substrate and proline iminopeptidase (0.03 U/g substrate from cabbage leaves (Brassica oleracea var. capitata, and aminopeptidase (0.2 U/g substrate from chick-pea cotyledons (Cicer arietinum L. were involved in the additional hydrolysis of the peptide mixtures. The degree of hydrolysis (DH, total phenolic contents, and protein contents of these hydrolysates were as follows: DH (about 20–28%, total phenolics (15.3–27.2 μg/mg sample powder, and proteins (162.7–242.8 μg/mg sample powder, respectively. The hydrolysates possessed high antiradical scavenging activity determined with DPPH (42–46% inhibition. The prepared hydrolysates of bee-collected flower pollen may be regarded as effective natural and functional dietary food supplements due to their remarkable content of polyphenol substances and significant radical-scavenging capacity with special regard to their nutritional-physiological implications.

  12. Conceptual process synthesis for recovery of natural products from plants

    DEFF Research Database (Denmark)

    Malwade, Chandrakant R.; Qu, Haiyan; Rong, Ben-Guang;

    2013-01-01

    A systematic method of conceptual process synthesis for recovery of natural products from their biological sources is presented. This methodology divides the task into two major subtasks namely, isolation of target compound from a chemically complex solid matrix of biological source (crude extract......) and purification of target compound(s) from the crude extract. Process analytical technology (PAT) is used in each step to understand the nature of material systems and separation characteristics of each separation method. In the present work, this methodology is applied to generate process flow sheet for recovery...

  13. High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

    OpenAIRE

    2011-01-01

    Background The description of new hydrolytic enzymes is an important step in the development of techniques which use lignocellulosic materials as a starting point for fuel production. Sugarcane bagasse, which is subjected to pre-treatment, hydrolysis and fermentation for the production of ethanol in several test refineries, is the most promising source of raw material for the production of second generation renewable fuels in Brazil. One problem when screening hydrolytic activities is that th...

  14. High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

    OpenAIRE

    2011-01-01

    Background: The description of new hydrolytic enzymes is an important step in the development of techniques which use lignocellulosic materials as a starting point for fuel production. Sugarcane bagasse, which is subjected to pre-treatment, hydrolysis and fermentation for the production of ethanol in several test refineries, is the most promising source of raw material for the production of second generation renewable fuels in Brazil. One problem when screening hydrolytic activities is that t...

  15. High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

    OpenAIRE

    2011-01-01

    Abstract Background The description of new hydrolytic enzymes is an important step in the development of techniques which use lignocellulosic materials as a starting point for fuel production. Sugarcane bagasse, which is subjected to pre-treatment, hydrolysis and fermentation for the production of ethanol in several test refineries, is the most promising source of raw material for the production of second generation renewable fuels in Brazil. One problem when screening hydrolytic activities i...

  16. Economic and Environmental Assessment of Natural Gas Plants with Carbon Capture and Storage (NGCC-CCS)

    Science.gov (United States)

    The CO2 intensity of electricity produced by state-of-the-art natural gas combined-cycle turbines (NGCC) isapproximately one-third that of the U.S. fleet of existing coal plants. Compared to new nuclear plants and coal plantswith integrated carbon capture, NGCC has a lower invest...

  17. Plant management in natural areas: balancing chemical, mechanical, and cultural control methods

    Science.gov (United States)

    Steven Manning; James. Miller

    2011-01-01

    After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

  18. Multiple RNA processing defects and impaired chloroplast function in plants deficient in the organellar protein-only RNase P enzyme.

    Directory of Open Access Journals (Sweden)

    Wenbin Zhou

    Full Text Available Transfer RNA (tRNA precursors undergo endoribonucleolytic processing of their 5' and 3' ends. 5' cleavage of the precursor transcript is performed by ribonuclease P (RNase P. While in most organisms RNase P is a ribonucleoprotein that harbors a catalytically active RNA component, human mitochondria and the chloroplasts (plastids and mitochondria of seed plants possess protein-only RNase P enzymes (PRORPs. The plant organellar PRORP (PRORP1 has been characterized to some extent in vitro and by transient gene silencing, but the molecular, phenotypic and physiological consequences of its down-regulation in stable transgenic plants have not been assessed. Here we have addressed the function of the dually targeted organellar PRORP enzyme in vivo by generating stably transformed Arabidopsis plants in which expression of the PRORP1 gene was suppressed by RNA interference (RNAi. PRORP1 knock-down lines show defects in photosynthesis, while mitochondrial respiration is not appreciably affected. In both plastids and mitochondria, the effects of PRORP1 knock-down on the processing of individual tRNA species are highly variable. The drastic reduction in the levels of mature plastid tRNA-Phe(GAA and tRNA-Arg(ACG suggests that these two tRNA species limit plastid gene expression in the PRORP1 mutants and, hence, are causally responsible for the mutant phenotype.

  19. Several genes encoding enzymes with the same activity are necessary for aerobic fungal degradation of cellulose in nature

    DEFF Research Database (Denmark)

    Busk, Peter Kamp; Lange, Mette; Pilgaard, Bo

    2014-01-01

    are hallmarks of cellulose-degrading fungi except brown rot fungi. Furthermore, a high number of AA9, endocellulase and β-glucosidase genes were identified, not in what are known to be the strongest, specialized lignocellulose degraders but in saprophytic fungi that can use a wide variety of substrates whereas...... only few of these genes were found in fungi that have a limited number of natural, lignocellulotic substrates. This correlation suggests that enzymes with different properties are necessary for degradation of cellulose in different complex substrates. Interestingly, clustering of the fungi based......The cellulose-degrading fungal enzymes are glycoside hydrolases of the GH families and lytic polysaccharide monooxygenases. The entanglement of glycoside hydrolase families and functions makes it difficult to predict the enzymatic activity of glycoside hydrolases based on their sequence...

  20. Radon emissions from natural gas power plants at The Pennsylvania State University.

    Science.gov (United States)

    Stidworthy, Alison G; Davis, Kenneth J; Leavey, Jeff

    2016-11-01

    Burning natural gas in power plants may emit radon ((222)Rn) into the atmosphere. On the University Park campus of The Pennsylvania State University, atmospheric radon enhancements were measured and modeled in the vicinity of their two power plants. The three-part study first involved measuring ambient outdoor radon concentrations from August 2014 through January 2015 at four sites upwind and downwind of the power plants at distances ranging from 80 m to 310 m. For each plant, one site served as a background site, while three other sites measured radon concentration enhancements downwind. Second, the radon content of natural gas flowing into the power plant was measured, and third, a plume dispersion model was used to predict the radon concentrations downwind of the power plants. These predictions are compared to the measured downwind enhancements in radon to determine whether the observed radon concentration enhancements could be attributed to the power plants' emissions. Atmospheric radon concentrations were consistently low as compared to the EPA action level of 148 Bq m(-3), averaging 34.5 ± 2.7 Bq m(-3) around the East Campus Steam Plant (ECSP) and 31.6 ± 2.7 Bq m(-3) around the West Campus Steam Plant (WCSP). Significant concentrations of radon, ranging from 516 to 1,240 Bq m(-3), were detected in the natural gas. The measured enhancements downwind of the ECSP averaged 6.2 Bq m(-3) compared to modeled enhancements of 0.08 Bq m(-3). Measured enhancements around the WCSP averaged -0.2 Bq m(-3) compared to the modeled enhancements of 0.05 Bq m(-3), which were not significant compared to observational error. The comparison of the measured to modeled downwind radon enhancements shows no correlation over time. The measurements of radon levels in the vicinity of the power plants appear to be unaffected by the emissions from the power plants. Radon measurements at sites surrounding power plants that utilize natural gas did not indicate that the radon concentrations

  1. ATP Binding Turns Plant Cryptochrome Into an Efficient Natural Photoswitch

    Science.gov (United States)

    Müller, Pavel; Bouly, Jean-Pierre; Hitomi, Kenichi; Balland, Véronique; Getzoff, Elizabeth D.; Ritz, Thorsten; Brettel, Klaus

    2014-06-01

    Cryptochromes are flavoproteins that drive diverse developmental light-responses in plants and participate in the circadian clock in animals. Plant cryptochromes have found application as photoswitches in optogenetics. We have studied effects of pH and ATP on the functionally relevant photoreduction of the oxidized FAD cofactor to the semi-reduced FADH. radical in isolated Arabidopsis cryptochrome 1 by transient absorption spectroscopy on nanosecond to millisecond timescales. In the absence of ATP, the yield of light-induced radicals strongly decreased with increasing pH from 6.5 to 8.5. With ATP present, these yields were significantly higher and virtually pH-independent up to pH 9. Analysis of our data in light of the crystallographic structure suggests that ATP-binding shifts the pKa of aspartic acid D396, the putative proton donor to FAD.-, from ~7.4 to >9, and favours a reaction pathway yielding long-lived aspartate D396-. Its negative charge could trigger conformational changes necessary for signal transduction.

  2. Degradation of pheromone and plant volatile components by a same odorant-degrading enzyme in the cotton leafworm, Spodoptera littoralis.

    Directory of Open Access Journals (Sweden)

    Nicolas Durand

    Full Text Available BACKGROUND: Odorant-Degrading Enzymes (ODEs are supposed to be involved in the signal inactivation step within the olfactory sensilla of insects by quickly removing odorant molecules from the vicinity of the olfactory receptors. Only three ODEs have been both identified at the molecular level and functionally characterized: two were specialized in the degradation of pheromone compounds and the last one was shown to degrade a plant odorant. METHODOLOGY: Previous work has shown that the antennae of the cotton leafworm Spodoptera littoralis, a worldwide pest of agricultural crops, express numerous candidate ODEs. We focused on an esterase overexpressed in males antennae, namely SlCXE7. We studied its expression patterns and tested its catalytic properties towards three odorants, i.e. the two female sex pheromone components and a green leaf volatile emitted by host plants. CONCLUSION: SlCXE7 expression was concomitant during development with male responsiveness to odorants and during adult scotophase with the period of male most active sexual behaviour. Furthermore, SlCXE7 transcription could be induced by male exposure to the main pheromone component, suggesting a role of Pheromone-Degrading Enzyme. Interestingly, recombinant SlCXE7 was able to efficiently hydrolyze the pheromone compounds but also the plant volatile, with a higher affinity for the pheromone than for the plant compound. In male antennae, SlCXE7 expression was associated with both long and short sensilla, tuned to sex pheromones or plant odours, respectively. Our results thus suggested that a same ODE could have a dual function depending of it sensillar localisation. Within the pheromone-sensitive sensilla, SlCXE7 may play a role in pheromone signal termination and in reduction of odorant background noise, whereas it could be involved in plant odorant inactivation within the short sensilla.

  3. The Action of Antidiabetic Plants of the Canadian James Bay Cree Traditional Pharmacopeia on Key Enzymes of Hepatic Glucose Homeostasis

    Directory of Open Access Journals (Sweden)

    Abir Nachar

    2013-01-01

    Full Text Available We determined the capacity of putative antidiabetic plants used by the Eastern James Bay Cree (Canada to modulate key enzymes of gluconeogenesis and glycogen synthesis and key regulating kinases. Glucose-6-phosphatase (G6Pase and glycogen synthase (GS activities were assessed in cultured hepatocytes treated with crude extracts of seventeen plant species. Phosphorylation of AMP-dependent protein kinase (AMPK, Akt, and Glycogen synthase kinase-3 (GSK-3 were probed by Western blot. Seven of the seventeen plant extracts significantly decreased G6Pase activity, Abies balsamea and Picea glauca, exerting an effect similar to insulin. This action involved both Akt and AMPK phosphorylation. On the other hand, several plant extracts activated GS, Larix laricina and A. balsamea, far exceeding the action of insulin. We also found a significant correlation between GS stimulation and GSK-3 phosphorylation induced by plant extract treatments. In summary, three Cree plants stand out for marked effects on hepatic glucose homeostasis. P. glauca affects glucose production whereas L. laricina rather acts on glucose storage. However, A. balsamea has the most promising profile, simultaneously and powerfully reducing G6Pase and stimulating GS. Our studies thus confirm that the reduction of hepatic glucose production likely contributes to the therapeutic potential of several antidiabetic Cree traditional medicines.

  4. Naturally occurring soil salinity does not reduce N-transforming enzymes or organisms

    Science.gov (United States)

    Soil salinity can negatively affect plant production and important biogeochemical cycles which are mainly carried out by soil microbes. The objective of this study was to contribute new information on soil biological N transformations by examining the impact primary salinity reduction has on a) the ...

  5. Cellular Ubc2/Rad6 E2 ubiquitin-conjugating enzyme facilitates tombusvirus replication in yeast and plants

    Energy Technology Data Exchange (ETDEWEB)

    Imura, Yoshiyuki, E-mail: imura@brs.nihon-u.ac.jp; Molho, Melissa; Chuang, Chingkai; Nagy, Peter D., E-mail: pdnagy2@uky.edu

    2015-10-15

    Mono- and multi-ubiquitination alters the functions and subcellular localization of many cellular and viral proteins. Viruses can co-opt or actively manipulate the ubiquitin network to support viral processes or suppress innate immunity. Using yeast (Saccharomyces cerevisiae) model host, we show that the yeast Rad6p (radiation sensitive 6) E2 ubiquitin-conjugating enzyme and its plant ortholog, AtUbc2, interact with two tombusviral replication proteins and these E2 ubiquitin-conjugating enzymes could be co-purified with the tombusvirus replicase. We demonstrate that TBSV RNA replication and the mono- and bi-ubiquitination level of p33 is decreased in rad6Δ yeast. However, plasmid-based expression of AtUbc2p could complement both defects in rad6Δ yeast. Knockdown of UBC2 expression in plants also decreases tombusvirus accumulation and reduces symptom severity, suggesting that Ubc2p is critical for virus replication in plants. We provide evidence that Rad6p is involved in promoting the subversion of Vps23p and Vps4p ESCRT proteins for viral replicase complex assembly. - Highlights: • Tombusvirus p33 replication protein interacts with cellular RAD6/Ubc2 E2 enzymes. • Deletion of RAD6 reduces tombusvirus replication in yeast. • Silencing of UBC2 in plants inhibits tombusvirus replication. • Mono- and bi-ubiquitination of p33 replication protein in yeast and in vitro. • Rad6p promotes the recruitment of cellular ESCRT proteins into the tombusvirus replicase.

  6. Productivity as related to diversity and age in planted versus natural forests

    Science.gov (United States)

    Qinfeng Guo; Hai Ren

    2014-01-01

    Little is known about the performance of plantations relative to natural forests of the same climate zone and age. China has more plantations than any other country as a consequence of massive afforestation efforts.We use data from China to comparatively examine tree biomass and productivity of planted and natural stands in relation to climate zone, latitude, elevation...

  7. Biosynthesis of natural products in plants by fungal endophytes with an emphasis on swainsonine

    Science.gov (United States)

    Plant natural products are frequently used as chemotaxonomic markers which are indicative of select members of a family, genus, and/or species. However, the erratic occurrence of some natural products raises questions about their biosynthetic origin and significance as chemotaxonomic markers. Rece...

  8. Soil Properties and Plant Biomass Production in Natural Rangeland Management Systems

    Directory of Open Access Journals (Sweden)

    Romeu de Souza Werner

    Full Text Available ABSTRACT Improper management of rangelands can cause land degradation and reduce the economic efficiency of livestock activity. The aim of this study was to evaluate soil properties and quantify plant biomass production in four natural rangeland management systems in the Santa Catarina Plateau (Planalto Catarinense of Brazil. The treatments, which included mowed natural rangeland (NR, burned natural rangeland (BR, natural rangeland improved through the introduction of plant species after harrowing (IH, and natural rangeland improved through the introduction of plant species after chisel plowing (IC, were evaluated in a Nitossolo Bruno (Nitisol. In the improved treatments, soil acidity was corrected, phosphate fertilizer was applied, and intercropped annual ryegrass (Lolium multiflorum, velvet grass (Holcus lanatus, and white clover (Trifolium repens were sown. Management systems with harrowed or chisel plowed soil showed improved soil physical properties; however, the effect decreased over time and values approached those of burned and mowed natural rangelands. Natural rangeland systems in the establishment phase had little influence on soil organic C. The mowed natural rangeland and improved natural rangeland exhibited greater production of grazing material, while burning the field decreased production and increased the proportion of weeds. Improvement of the natural rangelands increased leguminous biomass for pasture.

  9. Natural and planted flora of the log mountain surface - mined demonstration area, Bell County, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, R.L. [Berea College, KY (United States); Wade, G.L. [USDA Forest Service, Burlington, VT (United States); Straw, R.A. [Univ. of Tennessee Plateau Experiment Station, Crossville, TN (United States)

    1996-12-31

    A descriptive study of the naturally invading and planted flora was conducted during 1984-1985 on a 14- and 21-year-old contour surface mine the 14.2 ha Log Mountain Demonstration Area (LMDA), in Bell County, Kentucky. Six habitats are designated from areas created from coal mining; the 1963 bench, 1970 bench, bench highwalls, mine outslopes, mine seeps, and coal haul-telephone microwave tower road. Twenty-four of 25 woody and herbaceous species (11 indigenous, 13 non-indigenous) have persisted from plantings by personnel of the Northeastern Forest Experiment Station, USDA Forest Service. We recommend 11 native and exotic woody and herbaceous species for planting on coal surface-mined areas. An annotated list of vascular plants comprises 360 taxa (286 indigenous, 74 non-indigenous) in 224 genera from 82 families. Taxa consist of 1 Lycopodiophyta, 1 Equisetophyta, 8 Polypodiophyta, 7 Pinophyta, and 343 Magnoliophyta. The most species-rich families are the Asteraceae (64), Poaceae (39), Fabaceae (20), Cyperaceae (16), Rosaceae (13), and Lamiaceae (11). A total of 155 Bell County distribution records were documented. Three threatened Kentucky species (Gentiana decora, Liparis loeselii, Silene ovata) were present in refugial habitats created by surface mining. The high species richness has resulted from native and naturalized invading species from the environs, native and exotic planted species, and species from the remnant seed bank. Forest vegetation is a complex mosaic of natural and semi-natural plant communities on the unplanted and planted areas of LMDA.

  10. A metabolic pathway assembled by enzyme selection may support herbivory of leaf-cutter ants on plant starch.

    Science.gov (United States)

    Bacci, Maurício; Bueno, Odair Correa; Rodrigues, André; Pagnocca, Fernando Carlos; Somera, Alexandre Favarin; Silva, Aline

    2013-05-01

    Mutualistic associations shape the evolution in different organism groups. The association between the leaf-cutter ant Atta sexdens and the basidiomycete fungus Leucoagaricus gongylophorus has enabled them to degrade starch from plant material generating glucose, which is a major food source for both mutualists. Starch degradation is promoted by enzymes contained in the fecal fluid that ants deposit on the fungus culture in cut leaves inside the nests. To understand the dynamics of starch degradation in ant nests, we purified and characterized starch degrading enzymes from the ant fecal fluid and from laboratory cultures of L. gongylophorus and found that the ants intestine positively selects fungal α-amylase and a maltase likely produced by the ants, as a negative selection is imposed to fungal maltase and ant α-amylases. Selected enzymes are more resistant to catabolic repression by glucose and proposed to structure a metabolic pathway in which the fungal α-amylase initiates starch catalysis to generate byproducts which are sequentially degraded by the maltase to produce glucose. The pathway is responsible for effective degradation of starch and proposed to represent a major evolutionary innovation enabling efficient starch assimilation from plant material by leaf-cutters.

  11. Biosynthesis and molecular actions of specialized 1,4-naphthoquinone natural products produced by horticultural plants

    Science.gov (United States)

    Widhalm, Joshua R; Rhodes, David

    2016-01-01

    The 1,4-naphthoquinones (1,4-NQs) are a diverse group of natural products found in every kingdom of life. Plants, including many horticultural species, collectively synthesize hundreds of specialized 1,4-NQs with ecological roles in plant–plant (allelopathy), plant–insect and plant–microbe interactions. Numerous horticultural plants producing 1,4-NQs have also served as sources of traditional medicines for hundreds of years. As a result, horticultural species have been at the forefront of many basic studies conducted to understand the metabolism and function of specialized plant 1,4-NQs. Several 1,4-NQ natural products derived from horticultural plants have also emerged as promising scaffolds for developing new drugs. In this review, the current understanding of the core metabolic pathways leading to plant 1,4-NQs is provided with additional emphasis on downstream natural products originating from horticultural species. An overview on the biochemical mechanisms of action, both from an ecological and pharmacological perspective, of 1,4-NQs derived from horticultural plants is also provided. In addition, future directions for improving basic knowledge about plant 1,4-NQ metabolism are discussed. PMID:27688890

  12. Plant Pb Contents in Elevation Zones of the Changbai Mountain National Nature Reserve, China

    Institute of Scientific and Technical Information of China (English)

    BAI Jun-Hong; CUI Bao-Shan; DENG Wei; WANG Qing-Gai; DING Qiu-Yi

    2007-01-01

    Typical plants and soils of four elevation zones,mountain tundra(Zone A),Betula ermanii forest(Zone B),mountain dark coniferous forest(Zone C),and mountain coniferous and broad-leaf forest(Zone D),along the vertical gradient of the northern mountain slope of the Changbai Mountain National Nature Reserve,Jilin Province,China,were sampled to study the relationship between plant and soil Pb,and to compare the Pb levels in typical plant types within the same elevation zone.The Pb contents in the soil and plant samples were measured by using a flame atomic absorption spectrophotometer.The results showed that the average plant Pb contents of the four plant elevation zones were lower than the average worldwide level.except for Zone B,Compared with the average level in China or the average worldwide level,the soil Pb levels of the four plant zones were higher,with Zones D and B having the lowest and highest averages,respectively.Plant Pb levels fluctuated from the upper to the lower zones,in a pattern of low-high-low-high,which was the same as that of the soils in the four zones.Furthermore.plant Pb was closely related to soll Pb.Depending on the plant species and plant parts,large differences were found in the Pb levels of typical plants within each zone.In Zone A,Vaccinium uliginosum and Rhododendron redowskianum had higher Pb levels than the other plants.In Zone C,the Pb levels in the branches of both plant species were higher than those in the leaves,which was contrary to Zone D.In Zone B,the Pb levels in the plant parts varied greatly with plant species.

  13. Screening of natural antioxidants from traditional Chinese medicinal plants associated with treatment of rheumatic disease.

    Science.gov (United States)

    Gan, Ren-You; Kuang, Lei; Xu, Xiang-Rong; Zhang, Yuan; Xia, En-Qin; Song, Feng-Lin; Li, Hua-Bin

    2010-08-30

    In order to find new sources of natural antioxidants, the antioxidant capacities of 50 medicinal plants associated with treatment of rheumatic diseases were systemically evaluated using the ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, and their total phenolic contents were measured by the Folin-Ciocalteu method. Their antioxidant activities of some of these plants were analyzed for the first time. The FRAP and TEAC assay results suggested that the antioxidant compounds in these plants possessed free radicals scavenging activity and oxidant reducing power. A positive linear correlation between antioxidant capacities and total phenolic contents implied that phenolic compounds in these plants could be the main components contributing to the observed activities. The results showed that Geranium wilfordii, Loranthus parasiticus, Polygonum aviculare, Pyrrosia sheaeri, Sinomenium acutum and Tripterygium wilfordii possessed the highest antioxidant capacities and total phenolic content among 50 plants tested, and could be rich potential sources of natural antioxidants.

  14. Screening of Natural Antioxidants from Traditional Chinese Medicinal Plants Associated with Treatment of Rheumatic Disease

    Directory of Open Access Journals (Sweden)

    Hua-Bin Li

    2010-08-01

    Full Text Available In order to find new sources of natural antioxidants, the antioxidant capacities of 50 medicinal plants associated with treatment of rheumatic diseases were systemically evaluated using the ferric-reducing antioxidant power (FRAP and Trolox equivalent antioxidant capacity (TEAC assays, and their total phenolic contents were measured by the Folin–Ciocalteu method. Their antioxidant activities of some of these plants were analyzed for the first time. The FRAP and TEAC assay results suggested that the antioxidant compounds in these plants possessed free radicals scavenging activity and oxidant reducing power. A positive linear correlation between antioxidant capacities and total phenolic contents implied that phenolic compounds in these plants could be the main components contributing to the observed activities. The results showed that Geranium wilfordii, Loranthus parasiticus, Polygonum aviculare, Pyrrosia sheaeri, Sinomenium acutum and Tripterygium wilfordii possessed the highest antioxidant capacities and total phenolic content among 50 plants tested, and could be rich potential sources of natural antioxidants.

  15. Natural leaf senescence: probed by chlorophyll fluorescence, CO2 photosynthetic rate and antioxidant enzyme activities during grain filling in different rice cultivars.

    Science.gov (United States)

    Panda, Debabrata; Sarkar, Ramani Kumar

    2013-01-01

    Natural leaf senescence was investigated in four rainfed lowland rice cultivars, FR 13A (tolerant to submergence), Sabita and Sarala (adapted to medium depth, 0-50 cm stagnant flooding) and Dengi (conventional farmers' cultivar). Changes in the levels of pigment content, CO2 photosynthetic rate, photosystem II photochemistry and anti-oxidant enzyme activities of flag leaves during grain-filling stage were investigated. Chlorophyll content, photochemical efficiency of photosystem II and CO2 photosynthetic rate decreased significantly with the progress of grain-filling. Likely, the activities of antioxidant enzymes namely, superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase decreased with progress of grain-filling. A substantial difference was observed among the four cultivars for the sustainability index (SI) of different photosynthetic parameters and antioxidant enzyme activities; SIs of those parameters, in general, were lower in low yielding cultivar FR 13A compared to the other three cultivars. Among the four cultivars Sabita gave maximum grain yield. Yet, SI of Pn was greater in Sarala and Dengi compared to the Sabita. SIs of electron transport (ETo/CS), maximal photochemical efficiency (Fv/Fm), area above Fo and Fm, catalase and ascorbate peroxidase were also greater in Sarala and Dengi. The data showed that among the different Chl a fluorescence parameters, PI could be used with greater accuracy to distinguish slow and fast senescence rice cultivars during grain-filling period. It was concluded that maintaining the vitality of rice plants during grain-filling gave guarantee to synthesize carbohydrate, however greater yield could be realized provided superior yield attributing parameters are present.

  16. Enzyme-linked immunosorbent assay for the detection and identification of plant pathogenic bacteria (in particular for Erwinia amylovora and Clavibacter michiganensis subsp. sepedonicus).

    Science.gov (United States)

    Kokoskova, Blanka; Janse, Jaap D

    2009-01-01

    Enzyme-linked immunosorbent assay (ELISA) is the most commonly used serological diagnostic technique. A number of different ELISA formats can be used for the detection of bacterial plant pathogens and in particular Erwinia amylovora and Clavibacter michiganensis subsp. sepedonicus.

  17. Cell organelles from crassulacean acid metabolism (CAM) plants : II. Compartmentation of enzymes of the crassulacean acid metabolism.

    Science.gov (United States)

    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.

  18. Plant natural products: from traditional compounds to new emerging drugs in cancer therapy.

    Science.gov (United States)

    Ouyang, L; Luo, Y; Tian, M; Zhang, S-Y; Lu, R; Wang, J-H; Kasimu, R; Li, X

    2014-12-01

    Natural products are chemical compounds or substances produced naturally by living organisms. With the development of modern technology, more and more plant extracts have been found to be useful to medical practice. Both micromolecules and macromolecules have been reported to have the ability to inhibit tumour progression, a novel weapon to fight cancer by targeting its 10 characteristic hallmarks. In this review, we focus on summarizing plant natural compounds and their derivatives with anti-tumour properties, into categories, according to their potential therapeutic strategies against different types of human cancer. Taken together, we present a well-grounded review of these properties, hoping to shed new light on discovery of novel anti-tumour therapeutic drugs from known plant natural sources.

  19. Enzyme mediated synthesis of polypyrrole in the presence of chondroitin sulfate and redox mediators of natural origin

    Energy Technology Data Exchange (ETDEWEB)

    Grijalva-Bustamante, G.A. [Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Evans-Villegas, A.G. [Departamento de Ciencias Químico Biológicas, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Castillo-Castro, T. del, E-mail: terecat@polimeros.uson.mx [Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Castillo-Ortega, M.M. [Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Cruz-Silva, R. [Research Center for Exotic Nanocarbons, Shinshu University, 4-17-1 Wakasato, 380-8553, Nagano (Japan); Huerta, F. [Departamento Ingeniería Textil y Papelera, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell, 1, E-03801 Alcoy (Spain); Morallón, E. [Departamento Química Física e Instituto Universitario de Materiales, Universidad de Alicante, Ap. 99, E-03080 Alicante (Spain)

    2016-06-01

    Polypyrrole (PPy) was synthesized by enzyme mediated oxidation of pyrrole using naturally occurring compounds as redox mediators. The catalytic mechanism is an enzymatic cascade reaction in which hydrogen peroxide is the oxidizer and soybean peroxidase, in the presence of acetosyringone, syringaldehyde or vanillin, acts as a natural catalysts. The effect of the initial reaction composition on the polymerization yield and electrical conductivity of PPy was analyzed. Morphology of the PPy particles was studied by scanning electron microscopy and transmission electron microscopy whereas the chemical structure was studied by X-ray photoelectron and Fourier transformed infrared spectroscopic techniques. The redox mediators increased the polymerization yield without a significant modification of the electronic structure of PPy. The highest conductivity of PPy was reached when chondroitin sulfate was used simultaneously as dopant and template during pyrrole polymerization. Electroactive properties of PPy obtained from natural precursors were successfully used in the amperometric quantification of uric acid concentrations. PPy increases the amperometric sensitivity of carbon nanotube screen-printed electrodes toward uric acid detection. - Highlights: • A new method of pyrrole polymerization using naturally occurring redox mediators and doping agents was studied. • The catalytic efficiency of different redox mediators toward pyrrole oxidation was evaluated. • Two different naturally occurring polymers were studied as bifunctional steric stabilizer/doping agents. • Polypyrrole improves the amperometric response of carbon nanotube screen printed electrodes toward uric acid sensing.

  20. Effects of fluoride on germination, early growth and antioxidant enzyme activities of legume plant species Prosopis juliflora.

    Science.gov (United States)

    Saini, Poonam; Khan, Suphiya; Baunthiyal, Mamta; Sharma, Vinay

    2013-03-01

    Prosopis juliflora (Mimosoideae) is a fast growing and drought resistant tree of semi-arid region of India where fluoride (F) toxicity is a common problem. In the present investigations this species was fluoride tested to check their capacity as bioindicator plant and its efficiency to accumulate. To achieve this aim, P. juliflora seedlings grown in hydroponic culture containing different concentrations of F were analyzed for germination percentage together with some biochemical parameters viz, antioxidant enzyme activities, total chlorophyll and accumulation of F in different plant parts. After 15 days of treatment, root growth (r = -0.928, p < 0.01), shoot growth (r = -0.976, p < 0.01), vigor index (r = -0.984, p < 0.01) were in decreasing trend with increasing concentration of NaF. Both catalase (3.2 folds) and peroxidase (2.7 folds) enzymes activity increased with increase in F concentration. Plant accumulated larger portion of the F in the roots (1024.63 microg g(-1) d.wt.) followed by shoot (492.30 microg g(-1) d.wt.). As P. juliflora did not show any morphological changes (marginal and tip chlorosis of leaf portions, necrosis and together these features are referred to as leaf "tip-burn") therefore, this species may be used as suitable bioindicator species for potentially F affected areas. Further, higher accumulation of F in roots indicates that P. juliflora is a suitable species for the removal of F in phytoremediation purposes.

  1. The exploration of plant species in nature reserve of Mount Mutis East Nusa Tenggara Province

    Directory of Open Access Journals (Sweden)

    Solikin Solikin

    2016-04-01

    Full Text Available This research was aimed to explore and inventory the plant diversity, especially medicinal plants in Nature Reserve of Mount Mutis. Data were collected in Fatumnasi Village, Fatumnasi District of South Central Timor Regency in Octo-ber 2011 through plant exploration and interview the local people. Plants inventory was conducted along the tracks during exploration. Herbs vegetation analysis was conducted among the tree stands of Eucalyptus urophylla. In addi-tion, orchid vegetation analysis was only conducted to orchids that have been found attaching to Eucalyptus urophylla trees. Results showed that there were about 52 family, 78 genera and 84 species of plants in the observed area. Tree species was dominated by 'ampupu' (Eucalyptus urophylla, while orchid species was dominated by Eria retusa. Herbaceous plant communities were dominated by Centella asiatica, Cyperus sp. and Cynodon dactylon. There were about eight plant species of medicinal plants and one food plant species found in the forestthat have been known by local people. Keywords: exploration, inventory, Mount Mutis, nature reserve

  2. Phytohormonal basis for the plant growth promoting action of naturally occurring biostimulators.

    Science.gov (United States)

    Kurepin, Leonid V; Zaman, Mohammad; Pharis, Richard P

    2014-07-01

    There is increasing interest in the use of naturally occurring 'biostimulators' for enhancing the growth of agricultural and horticultural crops. Bacteria, fungi and protozoa, as well as marine algae-based seaweed extracts, can produce or contain biostimulators. The activity of biostimulators to promote plant growth is often attributed to their ability to directly or indirectly provide mineral nutrients (mostly N, but also P, S and other macro- and micro-nutrients) to plants. Alternatively, biostimulators are postulated to increase the plant's ability to assimilate these mineral nutrients, often in return for photo-assimilates (as occurs with certain bacteria and fungi associations). Although optimal growth of plants depends on the availability of adequate mineral nutritients, that growth (and also development, including reproduction) is also regulated by plant hormones (phytohormones), including gibberellins, auxins and cytokinins. This review describes and discusses the evidence that the presence or application of biostimulators also increases plant growth directly via phytohormone action and also influences the plant's ability to control its own hormone biosynthesis and homeostasis. Finally, it discusses the need for a better understanding of the role(s) that are played by the naturally occurring biostimulators associated with the plant in the crop field. It is suggested that better understanding will allow for optimal crop yield returns, since disruptions of phytohormone homeostasis in plant organs and tissues can yield either beneficial or sub-optimal outcomes.

  3. Natural Antioxidants, Lipid Profile, Lipid Peroxidation, Antioxidant Enzymes of Different Vegetable Oils

    Directory of Open Access Journals (Sweden)

    Eqbal M.A. Dauqan

    2011-08-01

    Full Text Available Antioxidant plays a very important role in the body defense system against Reactive Oxygen Species (ROS. The free radicals also play an important role in combustion, atmospheric chemistry, biochemistry and biotechnology including human physiology. Fats and oils are energy sources that are composed mostly of triacylglycerols. Lipid ptofile are risk indicators of coronary heart disease. Various types of lipoproteins exist, but the two most abundant are Low-density Lipoprotein (LDL and High-density Lipoprotein (HDL. Lipid peroxidation is the introduction of a functional group containing two catenated oxygyen atomsinto unsturated fatty acids in a free radical reaction. Life in oxygen has led to the evolution of biochemical adaptations that exploit the reactivity of Active Oxygen Species (AOS. Antioxidant enzymes are an important protective mechanism ROS. This paper highlight the functions of antioxidants in the blood and selected organs associated with health.

  4. Relating Nanoscale Accessibility within Plant Cell Walls to Improved Enzyme Hydrolysis Yields in Corn Stover Subjected to Diverse Pretreatments.

    Science.gov (United States)

    Crowe, Jacob D; Zarger, Rachael A; Hodge, David B

    2017-10-04

    Simultaneous chemical modification and physical reorganization of plant cell walls via alkaline hydrogen peroxide or liquid hot water pretreatment can alter cell wall structural properties impacting nanoscale porosity. Nanoscale porosity was characterized using solute exclusion to assess accessible pore volumes, water retention value as a proxy for accessible water-cell walls surface area, and solute-induced cell wall swelling to measure cell wall rigidity. Key findings concluded that delignification by alkaline hydrogen peroxide pretreatment decreased cell wall rigidity and that the subsequent cell wall swelling resulted increased nanoscale porosity and improved enzyme binding and hydrolysis compared to limited swelling and increased accessible surface areas observed in liquid hot water pretreated biomass. The volume accessible to a 90 Å dextran probe within the cell wall was found to be correlated to both enzyme binding and glucose hydrolysis yields, indicating cell wall porosity is a key contributor to effective hydrolysis yields.

  5. Indigenous West African plants as novel sources of polysaccharide degrading enzymes: application in the reduction of the viscosity of cereal porridges

    NARCIS (Netherlands)

    Dicko, M.H.; Hilhorst, M.H.; Traore, A.S.

    2005-01-01

    Ethnobotanical and biochemical surveys revealed that some local plants from West Africa are novel sources of polysaccharide degrading enzymes such as amylases and glucanases. The study shows that these enzymes could be used for various biotechnological applications. In a crude extract of Curculigo p

  6. Indigenous West African plants as novel sources of polysaccharide degrading enzymes: application in the reduction of the viscosity of cereal porridges

    NARCIS (Netherlands)

    Dicko, M.H.; Hilhorst, M.H.; Traore, A.S.

    2005-01-01

    Ethnobotanical and biochemical surveys revealed that some local plants from West Africa are novel sources of polysaccharide degrading enzymes such as amylases and glucanases. The study shows that these enzymes could be used for various biotechnological applications. In a crude extract of Curculigo

  7. Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

    Directory of Open Access Journals (Sweden)

    Lorenzo Vergani

    2017-07-01

    Full Text Available The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs, together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed

  8. Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation.

    Science.gov (United States)

    Vergani, Lorenzo; Mapelli, Francesca; Marasco, Ramona; Crotti, Elena; Fusi, Marco; Di Guardo, Antonio; Armiraglio, Stefano; Daffonchio, Daniele; Borin, Sara

    2017-01-01

    The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates

  9. Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

    KAUST Repository

    Vergani, Lorenzo

    2017-07-25

    The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates

  10. Two-flow simulation of the natural light field within a canopy of submerged aquatic plants

    Science.gov (United States)

    Ackleson, S. G.; Klemas, V.

    1986-01-01

    A two-flow model is developed to simulate a light field composed of both collimated and diffuse irradiance within natural waters containing a canopy of bottom-adhering plants. To account for the effects of submerging a canopy, the transmittance and reflectance terms associated with each plant structure (leaves, stems, fruiting bodies, etc.) are expressed as functions of the ratio of the refractive index of the plant material to the refractive index of the surrounding media and the internal transmittance of the plant stucture. Algebraic solutions to the model are shown to yield plausible physical explanations for unanticipated variations in volume reflectance spectra. The effect of bottom reflectance on the near-bottom light field is also investigated. These indicate that within light-limited submerged aquatic plant canopies, substrate reflectance may play an important role in determining the amount of light available to the plants and, therefore, canopy productivity.

  11. Plants as Natural Dyes for Jonegoroan Batik Processing in Jono Cultural Tourism Village, Bojonegoro, East Java

    Directory of Open Access Journals (Sweden)

    Nurizza Fauziyah

    2015-05-01

    Full Text Available Batik Jonegoroan is one of the potential tourism product in Jono Village, Bojonegoro. Batik was processed by traditional procedure using natural dyes from plants. In order to preserve the traditional batik which was colored by natural dyes from plant, the preservation of such plant were important. As far, there are no scientific data related to the species usage in Batik production. The aims of the research were identifying plant which were used as natural dyes in Batik processing. Data were collected ​​through observation, and  semi-structured interviews to batik craftsmen. Results of interviews were analyzed descriptively. The importance of plant was analyzed using Relative Frequency of Citation (RFC index. Based on the results, there are 12 plant species used as batik dye. It is consisted of Teak, Mahogany, Ketapang, Tamarind, Mangosteen, Mango, Suji, Pandan, Indigofera, Guava, Banana and Onion. Teak (Tectonagrandis L. and Mahogany (Swietenia mahogany L. have the highest value of RFC, 1.00. Both species were the most frequently cited species as sources of natural dyes. Extraction of Teak leaves produce red hearts and extraction of mahogany tree bark produces red-brown dye. Both of the color is the most important color in batik motifs. Keywords: batik Jonegoroan, Jono Cultural Tourism Village, perception, quality, RFC

  12. Diversity and strain specificity of plant cell wall degrading enzymes revealed by the draft genome of Ruminococcus flavefaciens FD-1.

    Directory of Open Access Journals (Sweden)

    Margret E Berg Miller

    Full Text Available BACKGROUND: Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels. METHODOLOGY/PRINCIPAL FINDINGS: The R. flavefaciens FD-1 genome was sequenced to 29x-coverage, based on pulsed-field gel electrophoresis estimates (4.4 Mb, and assembled into 119 contigs providing 4,576,399 bp of unique sequence. As much as 87.1% of the genome encodes ORFs, tRNA, rRNAs, or repeats. The GC content was calculated at 45%. A total of 4,339 ORFs was detected with an average gene length of 918 bp. The cellulosome model for R. flavefaciens was further refined by sequence analysis, with at least 225 dockerin-containing ORFs, including previously characterized cohesin-containing scaffoldin molecules. These dockerin-containing ORFs encode a variety of catalytic modules including glycoside hydrolases (GHs, polysaccharide lyases, and carbohydrate esterases. Additionally, 56 ORFs encode proteins that contain carbohydrate-binding modules (CBMs. Functional microarray analysis of the genome revealed that 56 of the cellulosome-associated ORFs were up-regulated, 14 were down-regulated, 135 were unaffected, when R. flavefaciens FD-1 was grown on cellulose versus cellobiose. Three multi-modular xylanases (ORF01222, ORF03896, and ORF01315 exhibited the highest levels of up-regulation. CONCLUSIONS/SIGNIFICANCE: The genomic evidence indicates that R. flavefaciens FD-1 has the largest known number of fiber-degrading enzymes likely to be arranged in a cellulosome architecture. Functional

  13. Natural radionuclides in soil profiles surrounding the largest coal-fired power plant in Serbia

    Directory of Open Access Journals (Sweden)

    Tanić Milan N.

    2016-01-01

    Full Text Available This study evaluates the influence of the largest Serbian coal-fired power plant on radionuclide concentrations in soil profiles up to 50 cm in depth. Thirty soil profiles were sampled from the plant surroundings (up to 10 km distance and analyzed using standard methods for soil physicochemical properties and gamma ray spectrometry for specific activities of natural radionuclides (40K, 226Ra and 232Th. Spatial and vertical distribution of radionuclides was determined and analyzed to show the relations between the specific activities in the soil and soil properties and the most influential factors of natural radionuclide variability were identified. The radiological indices for surface soil were calculated and radiological risk assessment was performed. The measured specific activities were similar to values of background levels for Serbia. The sampling depth did not show any significant influence on specific activities of natural radionuclides. The strongest predictor of specific activities of the investigated radionuclides was soil granulometry. All parameters of radiological risk assessment were below the recommended values and adopted limits. It appears that the coal-fired power plant does not have a significant impact on the spatial and vertical distribution of natural radionuclides in the area of interest, but technologically enhanced natural radioactivity as a consequence of the plant operations was identified within the first 1.5 km from the power plant. [Projekat Ministarstva nauke Republike Srbije br. III43009 i br. III41005

  14. The role and source of 5'-deoxyadenosyl radical in a carbon skeleton rearrangement catalyzed by a plant enzyme.

    Science.gov (United States)

    Ollagnier, S; Kervio, E; Rétey, J

    1998-10-23

    The last step in the biosynthesis of tropane alkaloids is the carbon skeleton rearrangement of littorine to hyoscyamine. The reaction is catalyzed by a cell-free extract prepared from cultured hairy roots of Datura stramonium. Adenosylmethionine stimulated the rearrangement 10-20-fold and showed saturation kinetics with an apparent Km of 25 microM. It is proposed that S-adenosylmethionine is the source of a 5'-deoxyadenosyl radical which initiates the rearrangement in a similar manner as it does in analogous rearrangements catalyzed by coenzyme B12-dependent enzymes. Possible roles of S-adenosylmethionine as a radical source in higher plants are discussed.

  15. Highlighting the Need for Systems-Level Experimental Characterization of Plant Metabolic Enzymes.

    Science.gov (United States)

    Engqvist, Martin K M

    2016-01-01

    The biology of living organisms is determined by the action and interaction of a large number of individual gene products, each with specific functions. Discovering and annotating the function of gene products is key to our understanding of these organisms. Controlled experiments and bioinformatic predictions both contribute to functional gene annotation. For most species it is difficult to gain an overview of what portion of gene annotations are based on experiments and what portion represent predictions. Here, I survey the current state of experimental knowledge of enzymes and metabolism in Arabidopsis thaliana as well as eleven economically important crops and forestry trees - with a particular focus on reactions involving organic acids in central metabolism. I illustrate the limited availability of experimental data for functional annotation of enzymes in most of these species. Many enzymes involved in metabolism of citrate, malate, fumarate, lactate, and glycolate in crops and forestry trees have not been characterized. Furthermore, enzymes involved in key biosynthetic pathways which shape important traits in crops and forestry trees have not been characterized. I argue for the development of novel high-throughput platforms with which limited functional characterization of gene products can be performed quickly and relatively cheaply. I refer to this approach as systems-level experimental characterization. The data collected from such platforms would form a layer intermediate between bioinformatic gene function predictions and in-depth experimental studies of these functions. Such a data layer would greatly aid in the pursuit of understanding a multiplicity of biological processes in living organisms.

  16. Biochemical characterization, homology modeling and docking studies of ornithine delta-aminotransferase--an important enzyme in proline biosynthesis of plants.

    Science.gov (United States)

    Sekhar, P Nataraj; Amrutha, R Naga; Sangam, Shubhada; Verma, D P S; Kishor, P B Kavi

    2007-11-01

    Ornithine delta-aminotransferase (OAT) is an important enzyme in proline biosynthetic pathway and is implicated in salt tolerance in higher plants. OAT transaminates ornithine to pyrroline 5-carboxylate, which is further catalyzed to proline by pyrroline 5-carboxylate reductase. The Vigna aconitifolia OAT cDNA, encoding a polypeptide of 48.1 kDa, was expressed in Escherichia coli and the enzyme was partially characterized following its purification using (NH(4))(2)SO(4) precipitation and gel filtration techniques. Optimal activity of the enzyme was observed at a temperature of 25 degrees C and pH 8.0. The enzyme appeared to be a monomer and exhibited high activity at 4mM ornithine. Proline did not show any apparent effect but isoleucine, valine and serine inhibited the activity when added into the assay mixture along with ornithine. Omission of pyridoxal 5'-phosphate from the reaction mixture reduced the activity of this enzyme by 60%. To further evaluate these biochemical observations, homology modeling of the OAT was performed based on the crystal structure of the ornithine delta-aminotransferase from humans (PDB code 1OAT) by using the software MODELLER6v2. With the aid of the molecular mechanics and dynamics methods, the final model was obtained and assessed subsequently by PROCHECK and VERIFY-3D graph. With this model, a flexible docking study with the substrate and inhibitors was performed and the results indicated that Gly106 and Lys256 in OAT are the important determinant residues in binding as they have strong hydrogen bonding contacts with the substrate and inhibitors. These observations are in conformity with the results obtained from experimental investigations.

  17. Mercury uptake and phytotoxicity in terrestrial plants grown naturally in the Gumuskoy (Kutahya) mining area, Turkey.

    Science.gov (United States)

    Sasmaz, Merve; Akgül, Bunyamin; Yıldırım, Derya; Sasmaz, Ahmet

    2016-01-01

    This study investigated mercury (Hg) uptake and transport from the soil to different plant parts by documenting the distribution and accumulation of Hg in the roots and shoots of 12 terrestrial plant species, all of which grow naturally in surface soils of the Gumuskoy Pb-Ag mining area. Plant samples and their associated soils were collected and analyzed for Hg content by ICP-MS. Mean Hg values in the soils, roots, and shoots of all plants were 6.914, 460, and 206 µg kg(-1), respectively and lower than 1. The mean enrichment factors for the roots (ECR) and shoots (ECS) of these plants were 0.06 and 0.09, respectively and lower than 1. These results show that the roots of the studied plants prevented Hg from reaching the aerial parts of the plants. The mean translocation factor (TLF) was 1.29 and higher than 1. The mean TLF values indicated that all 12 plant species had the ability to transfer Hg from the roots to the shoots but that transfer was more efficient in plants with higher ECR and ECS. Therefore, these plants could be useful for the biomonitoring of environmental pollution and for rehabilitating areas contaminated by Hg.

  18. Strength in numbers? Effects of multiple natural enemy species on plant performance.

    Science.gov (United States)

    Stephens, Andrea E A; Srivastava, Diane S; Myers, Judith H

    2013-06-01

    While plants are invariably attacked by numerous insects and pathogens, the consequences of multiple enemies for plant performance are poorly understood. In particular, a predictive framework is lacking for when to expect enemies to have independent versus non-independent effects on their host plant. This is problematic for weed biological control programmes where multiple enemies are frequently released with the possibility of antagonistic interactions that may reduce control. Here, we conduct an analysis of 74 unique plant-enemy-enemy combinations from 51 studies to determine the frequency of non-independent effects of natural enemies on host plant performance, and test a number of a priori predictions for determinants of independent and antagonistic effects of multiple enemies. For three-quarters of plant response measurements, enemies had independent effects on plant performance. In most of the remainder, multiple enemies led to less reduction in performance than that predicted from each enemy alone. Antagonistic effects occurred when enemies attacked the same plant part concurrently or attacked plant reproductive structures. These two predictors explained why antagonistic effects were particularly prevalent for weeds, plants in the family Asteraceae and enemies in the order Diptera. Our results suggest that a few simple rules about avoiding particular combinations of multiple enemies could improve biological control success.

  19. Natural selection on coding and noncoding DNA sequences is associated with virulence genes in a plant pathogenic fungus.

    Science.gov (United States)

    Rech, Gabriel E; Sanz-Martín, José M; Anisimova, Maria; Sukno, Serenella A; Thon, Michael R

    2014-09-04

    Natural selection leaves imprints on DNA, offering the opportunity to identify functionally important regions of the genome. Identifying the genomic regions affected by natural selection within pathogens can aid in the pursuit of effective strategies to control diseases. In this study, we analyzed genome-wide patterns of selection acting on different classes of sequences in a worldwide sample of eight strains of the model plant-pathogenic fungus Colletotrichum graminicola. We found evidence of selective sweeps, balancing selection, and positive selection affecting both protein-coding and noncoding DNA of pathogenicity-related sequences. Genes encoding putative effector proteins and secondary metabolite biosynthetic enzymes show evidence of positive selection acting on the coding sequence, consistent with an Arms Race model of evolution. The 5' untranslated regions (UTRs) of genes coding for effector proteins and genes upregulated during infection show an excess of high-frequency polymorphisms likely the consequence of balancing selection and consistent with the Red Queen hypothesis of evolution acting on these putative regulatory sequences. Based on the findings of this work, we propose that even though adaptive substitutions on coding sequences are important for proteins that interact directly with the host, polymorphisms in the regulatory sequences may confer flexibility of gene expression in the virulence processes of this important plant pathogen. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  20. Inhibition of human cytochrome P450 enzymes by the natural hepatotoxin safrole.

    Science.gov (United States)

    Ueng, Yune-Fang; Hsieh, Chih-Hang; Don, Ming-Jaw

    2005-05-01

    The hepatotoxin, safrole is a methylenedioxy phenyl compound, found in sassafras oil and certain other essential oils. Recombinant cytochrome P450 (CYP, P450) and human liver microsomes were studied to investigate the selective inhibitory effects of safrole on human P450 enzymes and the mechanisms of action. Using Escherichia coli-expressed human P450, our results demonstrated that safrole was a non-selective inhibitor of CYP1A2, CYP2A6, CYP2D6, CYP2E1, and CYP3A4 in the IC(50) order CYP2E1 Safrole strongly inhibited CYP1A2, CYP2A6, and CYP2E1 activities with IC(50) values less than 20 microM. Safrole caused competitive, non-competitive, and non-competitive inhibition of CYP1A2, CYP2A6 and CYP2E1 activities, respectively. The inhibitor constants were in the order CYP1A2 safrole strongly inhibited 7-ethoxyresorufin O-deethylation, coumarin hydroxylation, and chlorzoxazone hydroxylation activities. These results revealed that safrole was a potent inhibitor of human CYP1A2, CYP2A6, and CYP2E1. With relatively less potency, CYP2D6 and CYP3A4 were also inhibited.

  1. The copper tolerance strategies and the role of antioxidative enzymes in three plant species grown on copper mine.

    Science.gov (United States)

    Boojar, Massod Mashhadi Akbar; Goodarzi, Faranak

    2007-05-01

    This study was undertaken to identify the strategies and the status of antioxidant enzyme activities involved in three plant species tolerance against Cu-toxicity in copper mine. The following methods were used for evaluations in three wild type species; Datura stramonium, Malva sylvestris and Chenopodium ambrosioides. The level of chlorophyll and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) by spectrometry, malondialdehyde (MDA) and dityrosine by HPLC and the levels of Cu in tissues and soils by atomic absorption spectrometry (AAS). Analysis showed that total and available copper were at toxic levels for plants growing on contaminated soil (zone 1). However, there were not any visual and conspicuous symptoms of Cu toxicity in plant species. Among three species, excess copper was transferred only into the D. stramonium and C. ambrosioides tissues. The C. ambrosioides accumulated Cu in roots and then in leaves, in which the leaves chloroplasts stored Cu around two times of vacuoles. In D. stramonium most of Cu was accumulated in leaves in which the storage rate in vacuoles and chloroplasts were 42% and 8%, respectively. In zone 1, the chlorophyll levels increased significantly in leaves of C. ambrosioides with respect to the same plant growing on uncontaminated soil (zone 2). There was insignificant decrease in chlorophyll content of D. stramonium leaves, collected from zone 1 with respect to zone 2. The D. stramonium and C. ambrosioides in zone 1, both revealed significant increase in their tissues antioxidant enzyme activities in comparison with the same samples of zone 2. There was significant elevation in oxidative damage biomarkers; MDA and dityrosine, when the aerial parts of D. stramonium in zone 1 were compared with the same parts of zone 2. We concluded that there were different tolerance strategies in studied plant species that protected them against copper toxicity. In M. sylvestris, exclusion of Cu from

  2. Carbohydrate-active enzymes in pythium and their role in plant cell wall and storage polysaccharide degradation.

    Directory of Open Access Journals (Sweden)

    Marcelo M Zerillo

    Full Text Available Carbohydrate-active enzymes (CAZymes are involved in the metabolism of glycoconjugates, oligosaccharides, and polysaccharides and, in the case of plant pathogens, in the degradation of the host cell wall and storage compounds. We performed an in silico analysis of CAZymes predicted from the genomes of seven Pythium species (Py. aphanidermatum, Py. arrhenomanes, Py. irregulare, Py. iwayamai, Py. ultimum var. ultimum, Py. ultimum var. sporangiiferum and Py. vexans using the "CAZymes Analysis Toolkit" and "Database for Automated Carbohydrate-active Enzyme Annotation" and compared them to previously published oomycete genomes. Growth of Pythium spp. was assessed in a minimal medium containing selected carbon sources that are usually present in plants. The in silico analyses, coupled with our in vitro growth assays, suggest that most of the predicted CAZymes are involved in the metabolism of the oomycete cell wall with starch and sucrose serving as the main carbohydrate sources for growth of these plant pathogens. The genomes of Pythium spp. also encode pectinases and cellulases that facilitate degradation of the plant cell wall and are important in hyphal penetration; however, the species examined in this study lack the requisite genes for the complete saccharification of these carbohydrates for use as a carbon source. Genes encoding for xylan, xyloglucan, (galacto(glucomannan and cutin degradation were absent or infrequent in Pythium spp.. Comparative analyses of predicted CAZymes in oomycetes indicated distinct evolutionary histories. Furthermore, CAZyme gene families among Pythium spp. were not uniformly distributed in the genomes, suggesting independent gene loss events, reflective of the polyphyletic relationships among some of the species.

  3. Effect of Cadmium Stress on the Growth, Antioxidative Enzymes and Lipid Peroxidation in Two Kenaf (Hibiscus cannabinus L.) Plant Seedlings

    Institute of Scientific and Technical Information of China (English)

    LI Feng-tao; QI Jian-min; ZHANG Gao-yang; LIN Li-hui; FANG Ping-ping; TAO Ai-fen; XU Jian-tang

    2013-01-01

    The effects of cadmium stress on the growth, antioxidative enzymes and lipid peroxidation in two kenaf plants, Fuhong 991 and ZM412, were analysed under control (0.5-strength Hoagland’s nutrient solution) or five levels of cadmium stress (0.5-strength Hoagland’s nutrient solution containing different concentrations of Cd2+). The leaves and roots of control and cadmium-stressed plants were harvested after 3 wk. At the same Cd concentration, the Cd tolerance index of Fuhong 991 was higher than that of ZM412, indicating that Fuhong 991 may be more tolerant to Cd than ZM412. The superoxide dismutase (SOD), catalase activity (CAT) and peroxidase (POD) activities fluctuated in the leaves of the Cd-stressed plants compared to the control, whereas the glutathione reductase activity (GR) was much larger than the control for Fuhong 991, ensuring that sufficient quantities of GSH were available to respond to the cadmium stress. In comparison to the control, the dynamic tendency of the SOD, CAT and POD activities in roots of the Cd-stressed plants all increased and then declined, but the POD activity of Fuhong 991 remained nearly unchanged at all of the stress levels. The increase in the enzyme activities demonstrated that Fuhong 991 was more tolerant to cadmium than ZM 412. The lipid peroxidation was enhanced only in the leaves of Cd-stressed ZM 412. These findings indicated that antioxidative activities may play important roles in Cd-stressed Fuhong 991 and ZM 412 and that the leaf and root cell membranes of Fuhong 991 have a greater stability than those of ZM 412. For pollution monitoring purposes, the GR activity in the roots and leaves may serve as a biomarker of Cd for Fuhong 991, whereas lipid peroxidation may serve as biomarker for ZM 412.

  4. Screening of Natural Antioxidants from Traditional Chinese Medicinal Plants Associated with Treatment of Rheumatic Disease

    OpenAIRE

    Hua-Bin Li; Feng-Lin Song; En-Qin Xia; Yuan Zhang; Xiang-Rong Xu; Lei Kuang; Ren-You Gan

    2010-01-01

    In order to find new sources of natural antioxidants, the antioxidant capacities of 50 medicinal plants associated with treatment of rheumatic diseases were systemically evaluated using the ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, and their total phenolic contents were measured by the Folin–Ciocalteu method. Their antioxidant activities of some of these plants were analyzed for the first time. The FRAP and TEAC assay results suggested ...

  5. Circadian clock component, LHY, tells a plant when to respond photosynthetically to light in nature.

    Science.gov (United States)

    Joo, Youngsung; Fragoso, Variluska; Yon, Felipe; Baldwin, Ian T; Kim, Sang-Gyu

    2017-08-01

    The circadian clock is known to increase plant growth and fitness, and is thought to prepare plants for photosynthesis at dawn and dusk; whether this happens in nature was unknown. We transformed the native tobacco, Nicotiana attenuata to silence two core clock components, NaLHY (irLHY) and NaTOC1 (irTOC1). We characterized growth and light- and dark-adapted photosynthetic rates (Ac ) throughout a 24 h day in empty vector-transformed (EV), irLHY, and irTOC1 plants in the field, and in NaPhyA- and NaPhyB1-silenced plants in the glasshouse. The growth rates of irLHY plants were lower than those of EV plants in the field. While irLHY plants reduced Ac earlier at dusk, no differences between irLHY and EV plants were observed at dawn in the field. irLHY, but not EV plants, responded to light in the night by rapidly increasing Ac . Under controlled conditions, EV plants rapidly increased Ac in the day compared to dark-adapted plants at night; irLHY plants lost these time-dependent responses. The role of NaLHY in gating photosynthesis is independent of the light-dependent reactions and red light perceived by NaPhyA, but not NaPhyB1. In summary, the circadian clock allows plants not to respond photosynthetically to light at night by anticipating and gating red light-mediated in native tobacco. © 2017 Institute of Botany, Chinese Academy of Sciences.

  6. Multiple strategies to prevent oxidative stress in Arabidopsis plants lacking the malate valve enzyme NADP-malate dehydrogenase.

    Science.gov (United States)

    Hebbelmann, Inga; Selinski, Jennifer; Wehmeyer, Corinna; Goss, Tatjana; Voss, Ingo; Mulo, Paula; Kangasjärvi, Saijaliisa; Aro, Eva-Mari; Oelze, Marie-Luise; Dietz, Karl-Josef; Nunes-Nesi, Adriano; Do, Phuc T; Fernie, Alisdair R; Talla, Sai K; Raghavendra, Agepati S; Linke, Vera; Scheibe, Renate

    2012-02-01

    The nuclear-encoded chloroplast NADP-dependent malate dehydrogenase (NADP-MDH) is a key enzyme controlling the malate valve, to allow the indirect export of reducing equivalents. Arabidopsis thaliana (L.) Heynh. T-DNA insertion mutants of NADP-MDH were used to assess the role of the light-activated NADP-MDH in a typical C(3) plant. Surprisingly, even when exposed to high-light conditions in short days, nadp-mdh knockout mutants were phenotypically indistinguishable from the wild type. The photosynthetic performance and typical antioxidative systems, such as the Beck-Halliwell-Asada pathway, were barely affected in the mutants in response to high-light treatment. The reactive oxygen species levels remained low, indicating the apparent absence of oxidative stress, in the mutants. Further analysis revealed a novel combination of compensatory mechanisms in order to maintain redox homeostasis in the nadp-mdh plants under high-light conditions, particularly an increase in the NTRC/2-Cys peroxiredoxin (Prx) system in chloroplasts. There were indications of adjustments in extra-chloroplastic components of photorespiration and proline levels, which all could dissipate excess reducing equivalents, sustain photosynthesis, and prevent photoinhibition in nadp-mdh knockout plants. Such metabolic flexibility suggests that the malate valve acts in concert with other NADPH-consuming reactions to maintain a balanced redox state during photosynthesis under high-light stress in wild-type plants.

  7. Leucoagaricus gongylophorus produces diverse enzymes for the degradation of recalcitrant plant polymers in leaf-cutter ant fungus gardens.

    Science.gov (United States)

    Aylward, Frank O; Burnum-Johnson, Kristin E; Tringe, Susannah G; Teiling, Clotilde; Tremmel, Daniel M; Moeller, Joseph A; Scott, Jarrod J; Barry, Kerrie W; Piehowski, Paul D; Nicora, Carrie D; Malfatti, Stephanie A; Monroe, Matthew E; Purvine, Samuel O; Goodwin, Lynne A; Smith, Richard D; Weinstock, George M; Gerardo, Nicole M; Suen, Garret; Lipton, Mary S; Currie, Cameron R

    2013-06-01

    Plants represent a large reservoir of organic carbon comprised primarily of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous fungus that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and, using genomic and metaproteomic tools, we investigate its role in lignocellulose degradation in the gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in ant gardens and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that likely play an important role in lignocellulose degradation. Our study provides a detailed analysis of plant biomass degradation in leaf-cutter ant fungus gardens and insight into the enzymes underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.

  8. Online Intelligent Controllers for an Enzyme Recovery Plant: Design Methodology and Performance

    Directory of Open Access Journals (Sweden)

    M. S. Leite

    2010-01-01

    Full Text Available This paper focuses on the development of intelligent controllers for use in a process of enzyme recovery from pineapple rind. The proteolytic enzyme bromelain (EC 3.4.22.4 is precipitated with alcohol at low temperature in a fed-batch jacketed tank. Temperature control is crucial to avoid irreversible protein denaturation. Fuzzy or neural controllers offer a way of implementing solutions that cover dynamic and nonlinear processes. The design methodology and a comparative study on the performance of fuzzy-PI, neurofuzzy, and neural network intelligent controllers are presented. To tune the fuzzy PI Mamdani controller, various universes of discourse, rule bases, and membership function support sets were tested. A neurofuzzy inference system (ANFIS, based on Takagi-Sugeno rules, and a model predictive controller, based on neural modeling, were developed and tested as well. Using a Fieldbus network architecture, a coolant variable speed pump was driven by the controllers. The experimental results show the effectiveness of fuzzy controllers in comparison to the neural predictive control. The fuzzy PI controller exhibited a reduced error parameter (ITAE, lower power consumption, and better recovery of enzyme activity.

  9. Life Cycle Assessment of Producing Electricity in Thailand: A Case Study of Natural Gas Power Plant

    Directory of Open Access Journals (Sweden)

    Usapein Parnuwat

    2017-01-01

    Full Text Available Environmental impacts from natural gas power plant in Thailand was investigated in this study. The objective was to identify the hotspot of environmental impact from electricity production and the allocation of emissions from power plant was studied. All stressors to environment were collected for annual natural gas power plant operation. The allocation of environmental load between electricity and steam was done by WRI/WBCSD method. Based on the annual power plant operation, the highest of environmental impact was fuel combustion, followed by natural gas extraction, and chemical reagent. After allocation, the result found that 1 kWh of electricity generated 0.425 kgCO2eq and 1 ton of steam generated 225 kgCO2eq. When compared based on 1GJ of energy product, the result showed that the environmental impact of electricity is higher than steam product. To improve the environmental performance, it should be focused on the fuel combustion, for example, increasing the efficiency of gas turbine, and using low sulphur content of natural gas. This result can be used as guideline for stakeholder who engage with the environmental impact from power plant; furthermore, it can be useful for policy maker to understand the allocation method between electricity and steam products.

  10. The fungal cultivar of leaf-cutter ants produces specific enzymes in response to different plant substrates

    Energy Technology Data Exchange (ETDEWEB)

    Khadempour, Lily [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Zoology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA; Burnum-Johnson, Kristin E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Baker, Erin S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Nicora, Carrie D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Webb-Robertson, Bobbie-Jo M. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; White, Richard A. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Monroe, Matthew E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Huang, Eric L. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Smith, Richard D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Currie, Cameron R. [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA

    2016-10-26

    Herbivores use symbiotic microbes to help gain access to energy and nutrients from plant material. Leaf-cutter ants are a paradigmatic example, having tremendous impact on their ecosystems as dominant generalist herbivores through cultivation of a fungus, Leucoagaricus gongylophorous. Here we examine how this mutualism could facilitate the flexible substrate incorporation of the ants by providing leaf-cutter ant subcolonies four substrate types: leaves, flowers, oats, and a mixture of all three. Through metaproteomic analysis of the fungus gardens, we were able to identify and quantify 1766 different fungal proteins, including 161 biomass-degrading enzymes. This analysis revealed that fungal protein profiles were significantly different between subcolonies fed different substrates with the highest abundance of cellulolytic enzymes observed in the leaf and flower treatments. When the fungus garden is provided with leaves and flowers, which contain the majority of their energy in recalcitrant material, it increases its production of proteins that break down cellulose: endoglucanases, exoglucanase and β-glucosidase. Further, the complete metaproteomes for the leaves and flowers treatments were very similar, the mixed treatment closely resembled the treatment with oats alone. This suggests that when provided a mixture of substrates, the fungus garden preferentially produces enzymes necessary for breakdown of simpler, more digestible substrates. This flexible, substrate-specific response of the fungal cultivar allows the leaf-cutter ants to derive energy from a wide range of substrates, which may contribute to their ability to be dominant generalist herbivores.

  11. Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants.

    Science.gov (United States)

    Aylward, Frank O; Khadempour, Lily; Tremmel, Daniel M; McDonald, Bradon R; Nicora, Carrie D; Wu, Si; Moore, Ronald J; Orton, Daniel J; Monroe, Matthew E; Piehowski, Paul D; Purvine, Samuel O; Smith, Richard D; Lipton, Mary S; Burnum-Johnson, Kristin E; Currie, Cameron R

    2015-01-01

    Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

  12. Naturally occurring phenanthrene degrading bacteria associated with seeds of various plant species.

    Science.gov (United States)

    Fernet, Jennifer L; Lawrence, John R; Germida, James J

    2016-01-01

    Seeds of 11 of 19 plant species tested yielded naturally occurring phenanthrene degrading bacteria when placed on phenanthrene impression plates. Seed associated phenanthrene degrading bacteria were mostly detected on caragana, Canada thistle, creeping red fescue, western wheatgrass, and tall wheat grass. Based on 16S rRNA analysis the most common bacteria isolated from these seeds were strains belonging to the genera Enterobacteria, Erwinia, Burkholderia, Pantoea, Pseudomonas, and Sphingomonas. These plants may provide an excellent source of pre-adapted bacterial-plant associations highly suitable for use in remediation of contaminated soil environments.

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

    Directory of Open Access Journals (Sweden)

    Paz eAranega Bou

    2014-10-01

    Full Text Available 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 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 SA and 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-induced resistance (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.

  14. Combining proteomics and transcriptome sequencing to identify active plant-cell-wall-degrading enzymes in a leaf beetle

    Directory of Open Access Journals (Sweden)

    Kirsch Roy

    2012-11-01

    Full Text Available Abstract Background The primary plant cell wall is a complex mixture of polysaccharides and proteins encasing living plant cells. Among these polysaccharides, cellulose is the most abundant and useful biopolymer present on earth. These polysaccharides also represent a rich source of energy for organisms which have evolved the ability to degrade them. A growing body of evidence suggests that phytophagous beetles, mainly species from the superfamilies Chrysomeloidea and Curculionoidea, possess endogenous genes encoding complex and diverse families of so-called plant cell wall degrading enzymes (PCWDEs. The presence of these genes in phytophagous beetles may have been a key element in their success as herbivores. Here, we combined a proteomics approach and transcriptome sequencing to identify PCWDEs present in larval gut contents of the mustard leaf beetle, Phaedon cochleariae. Results Using a two-dimensional proteomics approach, we recovered 11 protein bands, isolated using activity assays targeting cellulose-, pectin- and xylan-degrading enzymes. After mass spectrometry analyses, a total of 13 proteins putatively responsible for degrading plant cell wall polysaccharides were identified; these proteins belong to three glycoside hydrolase (GH families: GH11 (xylanases, GH28 (polygalacturonases or pectinases, and GH45 (β-1,4-glucanases or cellulases. Additionally, highly stable and proteolysis-resistant host plant-derived proteins from various pathogenesis-related protein (PRs families as well as polygalacturonase-inhibiting proteins (PGIPs were also identified from the gut contents proteome. In parallel, transcriptome sequencing revealed the presence of at least 19 putative PCWDE transcripts encoded by the P. cochleariae genome. All of these were specifically expressed in the insect gut rather than the rest of the body, and in adults as well as larvae. The discrepancy observed in the number of putative PCWDEs between transcriptome and proteome

  15. Adenanthin, a new inhibitor of thiol-dependent antioxidant enzymes, impairs the effector functions of human natural killer cells.

    Science.gov (United States)

    Siernicka, Marta; Winiarska, Magdalena; Bajor, Malgorzata; Firczuk, Malgorzata; Muchowicz, Angelika; Bobrowicz, Malgorzata; Fauriat, Cyril; Golab, Jakub; Olive, Daniel; Zagozdzon, Radoslaw

    2015-09-01

    Natural killer (NK) cells are considered critical components of the innate and adaptive immune responses. Deficiencies in NK cell activity are common, such as those that occur in cancer patients, and they can be responsible for dysfunctional immune surveillance. Persistent oxidative stress is intrinsic to many malignant tumours, and numerous studies have focused on the effects of reactive oxygen species on the anti-tumour activity of NK cells. Indeed, investigations in animal models have suggested that one of the most important thiol-dependent antioxidant enzymes, peroxiredoxin 1 (PRDX1), is essential for NK cell function. In this work, our analysis of the transcriptomic expression pattern of antioxidant enzymes in human NK cells has identified PRDX1 as the most prominently induced transcript out of the 18 transcripts evaluated in activated NK cells. The change in PRDX1 expression was followed by increased expression of two other enzymes from the PRDX-related antioxidant chain: thioredoxin and thioredoxin reductase. To study the role of thiol-dependent antioxidants in more detail, we applied a novel compound, adenanthin, to induce an abrupt dysfunction of the PRDX-related antioxidant chain in NK cells. In human primary NK cells, we observed profound alterations in spontaneous and antibody-dependent NK cell cytotoxicity against cancer cells, impaired degranulation, and a decreased expression of activation markers under these conditions. Collectively, our study pinpoints the unique role for the antioxidant activity of the PRDX-related enzymatic chain in human NK cell functions. Further understanding this phenomenon will prospectively lead to fine-tuning of the novel NK-targeted therapeutic approaches to human disease. © 2015 John Wiley & Sons Ltd.

  16. Determination of the starch-phosphorylating enzyme activity in plant extracts

    DEFF Research Database (Denmark)

    Ritte, G.; Steup, M.; Kossmann, J.;

    2003-01-01

    For quantification of alpha-glucan, water dikinase(GWD) activity in crude extracts of plant tissues a radio-labeling assay was established that uses soluble starch and P-33-labeled ATP as phosphate acceptor and donor, respectively. A constant rate of starch labeling was observed only if the ATP...... incorporation of phosphate whereas extracts from potato (Solanum tuberosum L.) tuber expressing a GWD antisense construct exhibited less activity than the wild-type control. To our knowledge this is the first time that a quantification of the starch-phosphorylating activity has been achieved in plant crude...

  17. Induction of Defense-Related Enzymes in Banana Plants: Effect of Live and Dead Pathogenic Strain of Fusarium oxysporum f. sp. cubense

    OpenAIRE

    2013-01-01

    The aim of the present study was to scrutinize the response of banana (Grand Naine variety) plants when interacting with dead or live pathogen, Fusarium oxysporum f.sp. cubense, a causative agent of Panama disease. Response of plants was evaluated in terms of induction of defense-related marker enzyme activity, namely, peroxidase (POX), polyphenol oxidase (PPO), β-1,3 glucanase, chitinase, and phenolics. Plant's interaction with live pathogen resulted in early induction of defense to restrain...

  18. Fungal Enzymes and Yeasts for Conversion of Plant Biomass to Bioenergy and High-Value Products

    DEFF Research Database (Denmark)

    Lange, Lene

    2017-01-01

    in the conversion of plant biomass to value-added products. These products provide a basis for substituting fossil-derived fuels, chemicals, and materials, as well as unlocking the biomass potential of the agricultural harvest to yield more food and feed. This article focuses on the mycological basis for the fungal...

  19. Aldo-keto reductase enzymes detoxify glyphosate and improve herbicide resistance in plants.

    Science.gov (United States)

    Vemanna, Ramu S; Vennapusa, Amaranatha Reddy; Easwaran, Murugesh; Chandrashekar, Babitha K; Rao, Hanumantha; Ghanti, Kirankumar; Sudhakar, Chinta; Mysore, Kirankumar S; Makarla, Udayakumar

    2017-07-01

    In recent years, concerns about the use of glyphosate-resistant crops have increased because of glyphosate residual levels in plants and development of herbicide-resistant weeds. In spite of identifying glyphosate-detoxifying genes from microorganisms, the plant mechanism to detoxify glyphosate has not been studied. We characterized an aldo-keto reductase gene from Pseudomonas (PsAKR1) and rice (OsAKR1) and showed, by docking studies, both PsAKR1 and OsAKR1 can efficiently bind to glyphosate. Silencing AKR1 homologues in rice and Nicotiana benthamiana or mutation of AKR1 in yeast and Arabidopsis showed increased sensitivity to glyphosate. External application of AKR proteins rescued glyphosate-mediated cucumber seedling growth inhibition. Regeneration of tobacco transgenic lines expressing PsAKR1 or OsAKRI on glyphosate suggests that AKR can be used as selectable marker to develop transgenic crops. PsAKR1- or OsAKRI-expressing tobacco and rice transgenic plants showed improved tolerance to glyphosate with reduced accumulation of shikimic acid without affecting the normal photosynthetic rates. These results suggested that AKR1 when overexpressed detoxifies glyphosate in planta. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  20. Redox enzymes in the plant plasma membrane and their possible roles

    DEFF Research Database (Denmark)

    Berczi, A.; Møller, I.M.

    2000-01-01

    Purified plasma membrane (PM) vesicles from higher plants contain redox proteins with low-molecular-mass prosthetic groups such as flavins (both FMN and FAD), hemes, metals (Cu, Fe and Mn), thiol groups and possibly naphthoquinone (vitamin K-1), all of which are likely to participate in redox...

  1. Plant-like phosphofructokinase from Plasmodium falciparum belongs to a novel class of ATP-dependent enzymes.

    Science.gov (United States)

    Mony, Binny M; Mehta, Monika; Jarori, Gotam K; Sharma, Shobhona

    2009-11-01

    Malaria parasite-infected erythrocytes exhibit enhanced glucose utilisation and 6-phospho-1-fructokinase (PFK) is a key enzyme in glycolysis. Here we present the characterisation of PFK from the human malaria parasite Plasmodium falciparum. Of the two putative PFK genes on chromosome 9 (PfPFK9) and 11 (PfPFK11), only the PfPFK9 gene appeared to possess all the catalytic features appropriate for PFK activity. The deduced PfPFK proteins contain domains homologous to the plant-like pyrophosphate (PPi)-dependent PFK beta and alpha subunits, which are quite different from the human erythrocyte PFK protein. The PfPFK9 gene beta and alpha regions were cloned and expressed as His(6)- and GST-tagged proteins in Escherichia coli. Complementation of PFK-deficient E. coli and activity analysis of purified recombinant proteins confirmed that PfPFK9beta possessed catalytic activity. Monoclonal antibodies against the recombinant beta protein confirmed that the PfPFK9 protein has beta and alpha domains fused into a 200 kDa protein, as opposed to the independent subunits found in plants. Despite an overall structural similarity to plant PPi-PFKs, the recombinant protein and the parasite extract exhibited only ATP-dependent enzyme activity, and none with PPi. Unlike host PFK, the Plasmodium PFK was insensitive to fructose-2,6-bisphosphate (F-2,6-bP), phosphoenolpyruvate (PEP) and citrate. A comparison of the deduced PFK proteins from several protozoan PFK genome databases implicates a unique class of ATP-dependent PFK present amongst the apicomplexan protozoans.

  2. Enhanced transformation of TNT by Arabidopsis plants expressing an old yellow enzyme

    National Research Council Canada - National Science Library

    Zhu, Bo; Peng, Ri-He; Fu, Xiao-Yan; Jin, Xiao-Fen; Zhao, Wei; Xu, Jing; Han, Hong-Juan; Gao, Jian-Jie; Xu, Zhi-Sheng; Bian, Lin; Yao, Quan-Hong

    2012-01-01

    2,4,6-Trinitrotoluene (TNT) is released in nature from manufacturing or demilitarization facilities, as well as after the firing or detonation of munitions or leakage from explosive remnants of war...

  3. What are plants doing and when? Using plant phenology to facilitate sustainable natural resources management

    Science.gov (United States)

    Chong, Geneva W.; Allen, Leslie A.

    2012-01-01

    Climate change models for the northern Rocky Mountains predict changes in temperature and water availability that in turn will alter vegetation. Changes include timing of plant life-history events, or phenology, such as green-up, flowering and senescence, and shifts in species composition. Moreover, climate changes may favor different species, such as nonnative, annual grasses over native species. Changes in vegetation could make forage for ungulates, sage-grouse, and livestock available earlier in the growing season, but shifts in species composition and phenology may also result in earlier senescence (die-off or dormancy) and reduced overall forage production.

  4. The cost of carbon capture and storage for natural gas combined cycle power plants.

    Science.gov (United States)

    Rubin, Edward S; Zhai, Haibo

    2012-03-20

    This paper examines the cost of CO(2) capture and storage (CCS) for natural gas combined cycle (NGCC) power plants. Existing studies employ a broad range of assumptions and lack a consistent costing method. This study takes a more systematic approach to analyze plants with an amine-based postcombustion CCS system with 90% CO(2) capture. We employ sensitivity analyses together with a probabilistic analysis to quantify costs for plants with and without CCS under uncertainty or variability in key parameters. Results for new baseload plants indicate a likely increase in levelized cost of electricity (LCOE) of $20-32/MWh (constant 2007$) or $22-40/MWh in current dollars. A risk premium for plants with CCS increases these ranges to $23-39/MWh and $25-46/MWh, respectively. Based on current cost estimates, our analysis further shows that a policy to encourage CCS at new NGCC plants via an emission tax or carbon price requires (at 95% confidence) a price of at least $125/t CO(2) to ensure NGCC-CCS is cheaper than a plant without CCS. Higher costs are found for nonbaseload plants and CCS retrofits.

  5. Application of carbohydrate arrays coupled with mass spectrometry to detect activity of plant-polysaccharide degradative enzymes from the fungus Aspergillus niger

    Science.gov (United States)

    van Munster, Jolanda M.; Thomas, Baptiste; Riese, Michel; Davis, Adrienne L.; Gray, Christopher J.; Archer, David B.; Flitsch, Sabine L.

    2017-01-01

    Renewables-based biotechnology depends on enzymes to degrade plant lignocellulose to simple sugars that are converted to fuels or high-value products. Identification and characterization of such lignocellulose degradative enzymes could be fast-tracked by availability of an enzyme activity measurement method that is fast, label-free, uses minimal resources and allows direct identification of generated products. We developed such a method by applying carbohydrate arrays coupled with MALDI-ToF mass spectrometry to identify reaction products of carbohydrate active enzymes (CAZymes) of the filamentous fungus Aspergillus niger. We describe the production and characterization of plant polysaccharide-derived oligosaccharides and their attachment to hydrophobic self-assembling monolayers on a gold target. We verify effectiveness of this array for detecting exo- and endo-acting glycoside hydrolase activity using commercial enzymes, and demonstrate how this platform is suitable for detection of enzyme activity in relevant biological samples, the culture filtrate of A. niger grown on wheat straw. In conclusion, this versatile method is broadly applicable in screening and characterisation of activity of CAZymes, such as fungal enzymes for plant lignocellulose degradation with relevance to biotechnological applications as biofuel production, the food and animal feed industry. PMID:28220903

  6. Use of natural and artificial light in horticulture - interaction of plant and technology

    NARCIS (Netherlands)

    Hemming, S.

    2011-01-01

    In intensive horticultural cultivation natural light levels often limit crop production during several periods. For an optimum plant production and product quality light intensity, spectrum and photoperiod have to be adapted to the needs of the crops at every moment. Light has to be optimised

  7. Use of natural and artificial light in horticulture - interaction of plant and technology

    NARCIS (Netherlands)

    Hemming, S.

    2011-01-01

    In intensive horticultural cultivation natural light levels often limit crop production during several periods. For an optimum plant production and product quality light intensity, spectrum and photoperiod have to be adapted to the needs of the crops at every moment. Light has to be optimised togeth

  8. Relationship between humanity and plant natural resources – in the context of food and agriculture

    Science.gov (United States)

    Agriculture, the domestication, culture, and management of plants and animals, has led to profound social changes in human evolution and development; it can be considered as the basis for civilization. Roughly 12,000 years ago agriculture appeared independently in several parts of the world. A natur...

  9. Out of Nature: Why Drugs from Plants Matter to the Future of Humanity

    Directory of Open Access Journals (Sweden)

    Kris Gremillion

    2013-06-01

    Full Text Available Review of Out of Nature: Why Drugs from Plants Matter to the Future of Humanity. Kara Rogers. 2012. The University of Arizona Press, Tucson. Pp. 216. $19.95 (paper. ISBN 978-0-8165-2969-8.

  10. Discovery and resupply of pharmacologically active plant-derived natural products: A review.

    Science.gov (United States)

    Atanasov, Atanas G; Waltenberger, Birgit; Pferschy-Wenzig, Eva-Maria; Linder, Thomas; Wawrosch, Christoph; Uhrin, Pavel; Temml, Veronika; Wang, Limei; Schwaiger, Stefan; Heiss, Elke H; Rollinger, Judith M; Schuster, Daniela; Breuss, Johannes M; Bochkov, Valery; Mihovilovic, Marko D; Kopp, Brigitte; Bauer, Rudolf; Dirsch, Verena M; Stuppner, Hermann

    2015-12-01

    Medicinal plants have historically proven their value as a source of molecules with therapeutic potential, and nowadays still represent an important pool for the identification of novel drug leads. In the past decades, pharmaceutical industry focused mainly on libraries of synthetic compounds as drug discovery source. They are comparably easy to produce and resupply, and demonstrate good compatibility with established high throughput screening (HTS) platforms. However, at the same time there has been a declining trend in the number of new drugs reaching the market, raising renewed scientific interest in drug discovery from natural sources, despite of its known challenges. In this survey, a brief outline of historical development is provided together with a comprehensive overview of used approaches and recent developments relevant to plant-derived natural product drug discovery. Associated challenges and major strengths of natural product-based drug discovery are critically discussed. A snapshot of the advanced plant-derived natural products that are currently in actively recruiting clinical trials is also presented. Importantly, the transition of a natural compound from a "screening hit" through a "drug lead" to a "marketed drug" is associated with increasingly challenging demands for compound amount, which often cannot be met by re-isolation from the respective plant sources. In this regard, existing alternatives for resupply are also discussed, including different biotechnology approaches and total organic synthesis. While the intrinsic complexity of natural product-based drug discovery necessitates highly integrated interdisciplinary approaches, the reviewed scientific developments, recent technological advances, and research trends clearly indicate that natural products will be among the most important sources of new drugs also in the future.

  11. AepA of Pectobacterium is not involved in the regulation of extracellular plant cell wall degrading enzymes production.

    Science.gov (United States)

    Kõiv, Viia; Andresen, Liis; Mäe, Andres

    2010-06-01

    Plant cell wall degrading enzymes (PCWDE) are the major virulence determinants in phytopathogenic Pectobacterium, and their production is controlled by many regulatory factors. In this study, we focus on the role of the AepA protein, which was previously described to be a global regulator of PCWDE production in Pectobacterium carotovorum (Murata et al. in Mol Plant Microbe Interact 4:239-246, 1991). Our results show that neither inactivation nor overexpression of aepA affects PCWDE production in either Pectobacterium atrosepticum SCRI1043 or Pectobacterium carotovorum subsp. carotovorum SCC3193. The previously published observation based on the overexpression of aepA could be explained by the presence of the adjacent regulatory rsmB gene in the constructs used. Our database searches indicated that AepA belongs to the YtcJ subfamily of amidohydrolases. YtcJ-like amidohydrolases are present in bacteria, archaea, plants and some fungi. Although AepA has 28% identity with the formamide deformylase NfdA in Arthrobacter pascens F164, AepA was unable to catalyze the degradation of NdfA-specific N-substituted formamides. We conclude that AepA is a putative aminohydrolase not involved in regulation of PCWDE production.

  12. Parasitic plant in natural Boswellia papyrifera stands at Humera, Northern Ethiopia

    Institute of Scientific and Technical Information of China (English)

    Abraham Yirgu; Alemu Gezahgne; Habtemariam Kassa; Minilik Tsega

    2014-01-01

    In Boswellia papyrifera (Del.) Hochst natural stands, we stud-ied the association of parasitic plants with B. papyrifera trees from which frankincense was tapped and marketed for domestic and export markets. Data on the rate of infection of parasitic plants on B. papyrifera was collected in three transects located at separate locations around Baha kar, northern Ethiopia. Each transect had ten circular sample plots of 400 m2 and separated by 100 m. Species composition, DBH, height, crown di-ameter, number of main, secondary and tertiary branches and number of parasitic plants on individual trees were recorded. Sixteen tree species were recorded in the combined sample plots. The parasitic plant associ-ated with B. papyrifera was identified as Tapinanthus globiferus. This parasite infected 38% of Boswellia trees in sample plots. The infection rate of the parasitic plant varied from 1 to 33 per Boswellia tree. The infection of T. globiferus on B. papyrifera was predominantly limited to tertiary small branchlets arising from secondary branches;parasitic plants were absent on thick main and secondary branches. In all plots, infection of T. globiferus was exclusively limited to Boswellia trees. The influence of T. globiferus parasitism on growth of Boswellia trees and its influence on yield of incense production needs further investigation. Management of natural stands for frankincense production should include measures to reduce infection by T. globiferus.

  13. A survey of phytotoxic microbial and plant metabolites as potential natural products for pest management.

    Science.gov (United States)

    Schrader, Kevin K; Andolfi, Anna; Cantrell, Charles L; Cimmino, Alessio; Duke, Stephen O; Osbrink, Weste; Wedge, David E; Evidente, Antonio

    2010-09-01

    Phytotoxic microbial metabolites produced by certain phytopathogenic fungi and bacteria, and a group of phytotoxic plant metabolites including Amaryllidacea alkaloids and some derivatives of these compounds were evaluated for algicide, bactericide, insecticide, fungicide, and herbicide activities in order to discover natural compounds for potential use in the management and control of several important agricultural and household structural pests. Among the various compounds evaluated: i) ophiobolin A was found to be the most promising for potential use as a selective algicide; ii) ungeremine was discovered to be bactericidal against certain species of fish pathogenic bacteria; iii) cycasin caused significant mortality in termites; iv) cavoxin, ophiobolin A, and sphaeropsidin A were most active towards species of plant pathogenic fungi; and v) lycorine and some of its analogues (1-O-acetyllycorine and lycorine chlorohydrate) were highly phytotoxic in the herbicide bioassay. Our results further demonstrated that plants and microbes can provide a diverse and natural source of compounds with potential use as pesticides.

  14. The RNA silencing enzyme RNA polymerase v is required for plant immunity.

    Directory of Open Access Journals (Sweden)

    Ana López

    2011-12-01

    Full Text Available RNA-directed DNA methylation (RdDM is an epigenetic control mechanism driven by small interfering RNAs (siRNAs that influence gene function. In plants, little is known of the involvement of the RdDM pathway in regulating traits related to immune responses. In a genetic screen designed to reveal factors regulating immunity in Arabidopsis thaliana, we identified NRPD2 as the OVEREXPRESSOR OF CATIONIC PEROXIDASE 1 (OCP1. NRPD2 encodes the second largest subunit of the plant-specific RNA Polymerases IV and V (Pol IV and Pol V, which are crucial for the RdDM pathway. The ocp1 and nrpd2 mutants showed increases in disease susceptibility when confronted with the necrotrophic fungal pathogens Botrytis cinerea and Plectosphaerella cucumerina. Studies were extended to other mutants affected in different steps of the RdDM pathway, such as nrpd1, nrpe1, ago4, drd1, rdr2, and drm1drm2 mutants. Our results indicate that all the mutants studied, with the exception of nrpd1, phenocopy the nrpd2 mutants; and they suggest that, while Pol V complex is required for plant immunity, Pol IV appears dispensable. Moreover, Pol V defective mutants, but not Pol IV mutants, show enhanced disease resistance towards the bacterial pathogen Pseudomonas syringae DC3000. Interestingly, salicylic acid (SA-mediated defenses effective against PsDC3000 are enhanced in Pol V defective mutants, whereas jasmonic acid (JA-mediated defenses that protect against fungi are reduced. Chromatin immunoprecipitation analysis revealed that, through differential histone modifications, SA-related defense genes are poised for enhanced activation in Pol V defective mutants and provide clues for understanding the regulation of gene priming during defense. Our results highlight the importance of epigenetic control as an additional layer of complexity in the regulation of plant immunity and point towards multiple components of the RdDM pathway being involved in plant immunity based on genetic evidence

  15. Plant Size as Determinant of Species Richness of Herbivores, Natural Enemies and Pollinators across 21 Brassicaceae Species.

    Directory of Open Access Journals (Sweden)

    Hella Schlinkert

    Full Text Available Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto- and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground, the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness. We found a lower R2 for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their

  16. Plant Size as Determinant of Species Richness of Herbivores, Natural Enemies and Pollinators across 21 Brassicaceae Species.

    Science.gov (United States)

    Schlinkert, Hella; Westphal, Catrin; Clough, Yann; László, Zoltán; Ludwig, Martin; Tscharntke, Teja

    2015-01-01

    Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto- and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground), the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness). We found a lower R2 for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their natural enemies

  17. Granivory of invasive, naturalized, and native plants in communities differentially susceptible to invasion.

    Science.gov (United States)

    Connolly, B M; Pearson, D E; Mack, R N

    2014-07-01

    Seed predation is an important biotic filter that can influence abundance and spatial distributions of native species through differential effects on recruitment. This filter may also influence the relative abundance of nonnative plants within habitats and the communities' susceptibility to invasion via differences in granivore identity, abundance, and food preference. We evaluated the effect of postdispersal seed predators on the establishment of invasive, naturalized, and native species within and between adjacent forest and steppe communities of eastern Washington, USA that differ in severity of plant invasion. Seed removal from trays placed within guild-specific exclosures revealed that small mammals were the dominant seed predators in both forest and steppe. Seeds of invasive species (Bromus tectorum, Cirsium arvense) were removed significantly less than the seeds of native (Pseudoroegneria spicata, Balsamorhiza sagittata) and naturalized (Secale cereale, Centaurea cyanus) species. Seed predation limited seedling emergence and establishment in both communities in the absence of competition in a pattern reflecting natural plant abundance: S. cereale was most suppressed, B. tectorum was least suppressed, and P. spicata was suppressed at an intermediate level. Furthermore, seed predation reduced the residual seed bank for all species. Seed mass correlated with seed removal rates in the forest and their subsequent effects on plant recruitment; larger seeds were removed at higher rates than smaller seeds. Our vegetation surveys indicate higher densities and canopy cover of nonnative species occur in the steppe compared with the forest understory, suggesting the steppe may be more susceptible to invasion. Seed predation alone, however, did not result in significant differences in establishment for any species between these communities, presumably due to similar total small-mammal abundance between communities. Consequently, preferential seed predation by small

  18. Extraction and characterization of latex and natural rubber from rubber-bearing plants.

    Science.gov (United States)

    Buranov, Anvar U; Elmuradov, Burkhon J

    2010-01-27

    Consecutive extraction of latex and natural rubber from the roots of rubber-bearing plants such as Taraxacum kok-saghyz (TKS), Scorzonera tau-saghyz (STS), and Scorzonera Uzbekistanica (SU) were carried out. Latex extraction was carried via two methods: Blender method and Flow method. The results of latex extraction were compared. Cultivated rubber-bearing plants contained slightly higher latex contents compared to those from wild fields. Several creaming agents for latex extraction were compared. About 50% of total natural rubber was extracted as latex. The results of the comparative studies indicated that optimum latex extraction can be achieved with Flow method. The purity of latex extracted by Blender method ( approximately 75%) was significantly lower than that extracted by Flow method (99.5%). When the latex particles were stabilized with casein, the latex was concentrated significantly. Through concentrating latex by flotation, the latex concentration of 35% was obtained. Bagasse contained mostly solid natural rubber. The remaining natural rubber in the bagasse (left after the latex extraction) was extracted using sequential solvent extraction first with acetone and then with several nonpolar solvents. Solid natural rubber was analyzed for gel content and characterized by size exclusion chromatography (SEC) for molecular weight determinations. SEC of solid natural rubber has shown that the molecular weight is about 1.8E6 and they contain less gel compared to TSR20 (Grade 20 Technically Specified Rubber), a commercial natural rubber from Hevea brasiliensis.

  19. Increasing CO[sub 2] and plant-plant interactions - effects on natural vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, H.B.; Polley, H.W.; Mayeux, H.S. (USDA ARS, Temple, TX (USA). Grassland Soil and Water Research Lab.)

    1993-01-01

    Plant species and functional groups of species show marked differences in photosynthesis and growth in relation to rising atmospheric CO[sub 2] concentrations through the range of the 30% increase of the recent past and the 100% increase since the last glaciation. A large shift was found in the compositional mix of 26 species of C3's and 17 species of C4's grown from a native soil seed bank in a competitive mode along a CO[sub 2] gradient that approximated the CO[sub 2] increase of the past 150 years and before. The biomass of C3's increased from near zero to 50% of the total while that of the C4's was reduced 25% as CO[sub 2] levels approached current ambient. The proposition that acclimation to rising CO[sub 2] will largely negate the fertilization effect of higher CO[sub 2] levels on C3's is not supported. No signs of photosynthetic acclimation were evident for Avena sativa. Prosopis glandulosa and Schizachvrium scoparium plants grown in subambient CO[sub 2]. The effects of changing CO[sub 2] levels on vegetation since the last glaciation are thought to have been at least as great, if not greater, than those which should be expected for a doubling of current CO[sub 2] levels. Atmospheric CO[sub 2] concentrations below 200 ppm are thought to have been instrumental in the rise of the C4 grasslands of North America and other extensive C4 grasslands and savannas of the world. Dramatic invasion of these areas by woody C3 species are accompanying the historical increase in atmospheric CO[sub 2] concentration now in progress. 63 refs., 6 figs., 2 tabs.

  20. Volatile compounds of healthy and insect-damaged Hippophae rhamnoides sinensis in natural and planted forests.

    Science.gov (United States)

    Zong, Shixiang; Luo, Youqing; Zhou, Jiao; Liu, Shujing

    2012-01-01

    Volatile compounds of healthy and insect-damaged stems of Hippophae rhamnoides sinensis were analysed using dynamic headspace and thermal-desorption cold-trap injector gas chromatography/mass spectroscopy (TCT-GC/MS). Sixteen compounds, belonging to alkanes, alcohols, aldehydes, esters, ketones, and ethers, were identified in the stems of healthy H. rhamnoides sinensis; the compounds in H. rhamnoides sinensis occurring naturally or cultivated in plantations were similar, but the relative contents were significantly different. In plants damaged by Holcocerus hippophaecolus, the nature and content of the volatile compounds were greatly changed. Butanedione and butyl glyoxylate were newly generated after damage by the pest, and the relative levels of pentanal, heptanal, eucalyptol, terpineol, and camphor were sharply increased in both naturally occurring and plantation-grown plants. n-Decane, trans-2-nonen-1-ol, and n-hexadecane levels increased in plants cultivated in the plantation and decreased in natural forests, whereas the levels of other types were reduced. Thus, both the nature and the content of volatile compounds of H. rhamnoides sinensis are affected by H. hippophaecolus damage, providing a theoretical basis to identify the mechanism of pest destruction.

  1. Single-walled carbon nanotube release affects the microbial enzyme-catalyzed oxidation processes of organic pollutants and lignin model compounds in nature.

    Science.gov (United States)

    Chen, Ming; Qin, Xiaosheng; Zeng, Guangming

    2016-11-01

    The question how microbial enzyme-catalyzed oxidation processes of organic pollutants and lignin model compounds (LMCs) are affected by the release of single-walled carbon nanotube (SWCNT) into the environment remains to be addressed at the molecular level. We have, therefore concentrated the effects of SWCNT on some important properties associated with enzyme activity and function during microbial oxidation of polycyclic aromatic hydrocarbons (benzo(a)pyrene, acenaphthene and anthracene), LMCs (2,6-dimethoxyphenol, guaiacol and veratryl alcohol) and β-hexachlorocyclohexane, including the behaviour of water molecules, hydrogen bonds (HBs) and hydrophobic interactions (HYs) between ligand and the enzyme, and conformational dynamics in N- and C-terminus. Our study revealed that SWCNT significantly affected the behaviour of water molecules within 5 Å of both these substrates and their respective enzymes during oxidation (p microbial enzyme-catalyzed processes of organic pollutants and LMCs in nature.

  2. Flora robotica -- An Architectural System Combining Living Natural Plants and Distributed Robots

    DEFF Research Database (Denmark)

    Hamann, Heiko; Divband Soorati, Mohammad; Heinrich, Mary Katherine

    2017-01-01

    Key to our project flora robotica is the idea of creating a bio-hybrid system of tightly coupled natural plants and distributed robots to grow architectural artifacts and spaces. Our motivation with this ground research project is to lay a principled foundation towards the design and implementation...... of living architectural systems that provide functionalities beyond those of orthodox building practice, such as self-repair, material accumulation and self-organization. Plants and robots work together to create a living organism that is inhabited by human beings. User-defined design objectives help...... to steer the directional growth of the plants, but also the system's interactions with its inhabitants determine locations where growth is prohibited or desired (e.g., partitions, windows, occupiable space). We report our plant species selection process and aspects of living architecture. A leitmotif...

  3. Determining light requirements of groundcover plants from subtropical natural forest using hemispherical photography

    Science.gov (United States)

    Zhang, Yi; Zhong, Yonglin; Xu, Mingfeng; Su, Zhiyao

    2017-01-01

    In order to determine light requirements of indigenous groundcover plants for potential use in urban landscaping, we conducted a plant census in Yinpingshan Nature Reserve, Dongguan, China, and measured canopy structure and understory light regimes using hemispherical photography. We found that canopy openness, transmitted direct solar radiation, and transmitted diffuse solar radiation exhibited highly significant spatial heterogeneity. Species composition and diversity of groundcover plants were highly dependent on canopy structure and understory light condition. Greater diversity and more stems of groundcover plants were associated with greater canopy openness and understory radiation in most cases. Highly significant differences in species composition were detected along canopy openness, transmitted direct solar radiation, and transmitted diffuse solar radiation gradients, respectively. We also detected indicator species for specific understory light regimes, which will provide useful information when applying such species in urban greening under various light environments.

  4. The Root Growth-Regulating Brevicompanine Natural Products Modulate the Plant Circadian Clock.

    Science.gov (United States)

    de Montaigu, Amaury; Oeljeklaus, Julian; Krahn, Jan H; Suliman, Mohamed N S; Halder, Vivek; de Ansorena, Elisa; Nickel, Sabrina; Schlicht, Markus; Plíhal, Ondřej; Kubiasová, Karolina; Radová, Lenka; Kracher, Barbara; Tóth, Réka; Kaschani, Farnusch; Coupland, George; Kombrink, Erich; Kaiser, Markus

    2017-06-16

    Plant growth regulating properties of brevicompanines (Brvs), natural products of the fungus Penicillium brevicompactum, have been known for several years, but further investigations into the molecular mechanism of their bioactivity have not been performed. Following chemical synthesis of brevicompanine derivatives, we studied their activity in the model plant Arabidopsis by a combination of plant growth assays, transcriptional profiling, and numerous additional bioassays. These studies demonstrated that brevicompanines cause transcriptional misregulation of core components of the circadian clock, whereas other biological read-outs were not affected. Brevicompanines thus represent promising chemical tools for investigating the regulation of the plant circadian clock. In addition, our study also illustrates the potential of an unbiased -omics-based characterization of bioactive compounds for identifying the often cryptic modes of action of small molecules.

  5. Reminiscences of research on the chemistry and biology of natural sterols in insects, plants and humans.

    Science.gov (United States)

    Ikekawa, Nobuo; Fujimoto, Yoshinori; Ishiguro, Masaji

    2013-01-01

    Natural sterols often occur as a heterogeneous mixture of homologs, which had disturbed the progress of steroid research. Development and application of GC methodology overcame this difficulty and enabled us to obtain detailed sterol profiles. Together, fine synthesis of stereo-defined isomers and homologs of steroids having oxygenated side chains allowed us to compare them with natural samples as well as to investigate structure-activity relationship. Advance of HPLC technology also facilitated the determination of the stereochemical structure of naturally occurring steroidal compounds, which were obtained only in minute amounts. This review highlights three topics out of our steroid research that have been performed mainly at Tokyo Institute of Technology around 1970-1990. These are sterol metabolism in insects focusing on the mechanism of the conversion of plant sterols to cholesterol and ecdysone biosynthesis, the synthesis and biochemical research of active forms of vitamin D3 derivatives, and the synthesis and microanalysis of plant hormone brassinosteroids.

  6. Plant essential oils potency as natural antibiotic in Indonesian medicinal herb of “jamu”

    Science.gov (United States)

    Soetjipto, H.; Martono, Y.

    2017-02-01

    The main purposes of this study are to compile antibacterial activity data of essential oils from Indonesian’s plants in order which can be used as a natural antibiotic in “jamu” to increase potential Indonesian medicinal herb. By using Agar Diffusing method, Bioautography and Gas Chromatography Mass Spectrum, respectively, antibacterial activity and chemical compounds of 12 plants essential oils were studied in the Natural Product Chemistry Laboratory, Department of Chemistry, Faculty of Science and Mathematics, Satya Wacana Christian University, Salatiga since 2007 until 2015. The results of this studies showed that all of the essential oils have a medium to a strong antibacterial activity which are in the range of 30 – 2,500 μg and 80-5,000 μg. Further on, the essential oils analyzed by GCMS showed that each essential oils have different dominant compounds. These data can be used as basic doses in the usage of essential oils as natural antibiotics.

  7. Trait differences between naturalized and invasive plant species independent of residence time and phylogeny.

    Science.gov (United States)

    Gallagher, R V; Randall, R P; Leishman, M R

    2015-04-01

    The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species' native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the inclusion

  8. The relationship between microsomal enzyme induction and liver tumour formation : a study on the effects of xenobiotic and naturally occurring microsomal enzyme inducers on livers of male CF-1 mice

    NARCIS (Netherlands)

    Tennekes, H.A.

    1979-01-01

    The effects of naturally occurring microsomal enzyme inducers on important hepatocellular pathways for the metabolism of foreign compounds (xenobiotics) and also upon the incidence of liver tumours in CF-1 mice treated or not with 10 mg dieldrin.kg -1diet were inves

  9. The relationship between microsomal enzyme induction and liver tumour formation : a study on the effects of xenobiotic and naturally occurring microsomal enzyme inducers on livers of male CF-1 mice

    NARCIS (Netherlands)

    Tennekes, H.A.

    1979-01-01

    The effects of naturally occurring microsomal enzyme inducers on important hepatocellular pathways for the metabolism of foreign compounds (xenobiotics) and also upon the incidence of liver tumours in CF-1 mice treated or not with 10 mg dieldrin.kg

  10. Antioxidant and antitopoisomerase activities in plant extracts of some Colombian flora from La Marcada Natural Regional Park.

    Science.gov (United States)

    Niño, Jaime; Correa, Yaned Milena; Cardona, Germán David; Mosquera, Oscar Marino

    2011-09-01

    Many plants have been used to treat some diseases and infections since time immemorial, and this potential has been exploited by the pharmaceutical industry in the search of new analgesic, anticarcinogenic and antimicrobial agents, among other active agents. In order to contribute with bioprospection studies on the Colombian flora, 35 extracts from 13 plant species belonging to seven families (Apocynaceae, Cactaceae, Costaceae, Eremolepidaceae, Passifloraceae, Solanaceae and Urticaceae) were collected from La Marcada Natural Regional Park (LMNRP), Colombia. Dichloromethane, n-hexane and aqueous-methanol crude extracts were prepared and evaluated for their activity against Saccharomyces cerevisiae RS322N, R52Y and RS321 strains in the yeast mutant assay and their antioxidant capacity through the DPPH test. The dichloromethane extract from Myriocarpa stipitata (Urticaceae) showed moderate inhibitory activity against the three S. cerevisiae strains tested. The capacity of the dichloromethane extract from M. stipitata to inhibit the enzyme topoisomerase I and to cause DNA damage was inferred from these results. In the DPPH assay, the n-hexane crude extract from Costus sp. (Costaceae) showed good antioxidant activity (48%); in addition, the crude dichloromethane and aqueous-methanol extracts from Rhipsalis micrantha (Cactaceae) showed moderate antioxidant activity with percentage of 29 and 21%, respectively.

  11. Engineering microbial cell factories for the production of plant natural products: from design principles to industrial-scale production.

    Science.gov (United States)

    Liu, Xiaonan; Ding, Wentao; Jiang, Huifeng

    2017-07-19

    Plant natural products (PNPs) are widely used as pharmaceuticals, nutraceuticals, seasonings, pigments, etc., with a huge commercial value on the global market. However, most of these PNPs are still being extracted from plants. A resource-conserving and environment-friendly synthesis route for PNPs that utilizes microbial cell factories has attracted increasing attention since the 1940s. However, at the present only a handful of PNPs are being produced by microbial cell factories at an industrial scale, and there are still many challenges in their large-scale application. One of the challenges is that most biosynthetic pathways of PNPs are still unknown, which largely limits the number of candidate PNPs for heterologous microbial production. Another challenge is that the metabolic fluxes toward the target products in microbial hosts are often hindered by poor precursor supply, low catalytic activity of enzymes and obstructed product transport. Consequently, despite intensive studies on the metabolic engineering of microbial hosts, the fermentation costs of most heterologously produced PNPs are still too high for industrial-scale production. In this paper, we review several aspects of PNP production in microbial cell factories, including important design principles and recent progress in pathway mining and metabolic engineering. In addition, implemented cases of industrial-scale production of PNPs in microbial cell factories are also highlighted.

  12. Occupational exposure to natural radiation in zirconium refractory plants in Japan.

    Science.gov (United States)

    Iwaoka, Kazuki; Tabe, Hiroyuki; Suzuki, Toshikazu; Yonehara, Hidenori

    2013-02-01

    The authors measured the ambient dose rate and activity concentration of natural radionuclides in raw materials, products, and aerosols on worksites, as well as the (222)Rn and (220)Rn concentrations in an unshaped refractory, a shaped refractory, and an electrocast refractory plant processing zirconium ore in Japan. Estimations were made of the effective doses to plant workers. The activity concentration of the (238)U series in raw materials and products in the refractory plants was higher than the critical values (10 Bq g(-1) for (40)K and 1 Bq g(-1) for all other radionuclides of natural origin) specified in the International Atomic Energy Agency Safety Guide. The ambient dose rate in the raw material warehouse of the electrocast refractory plant was 0.75 μSv h(-1), which was the highest among all the worksites at all the refractory plants studied. The activity concentrations of aerosols in the product-output site of the unshaped refractory plant was 0.0015 Bq m for U and 0.00078 Bq m(-3) for (232)Th, which were the highest of all the worksites for all refractory plants. The indoor (222)Rn and (220)Rn concentrations in all worksites of all the refractory plants were almost the same levels as those in everyday indoor places in Japan. The maximum value of the effective dose to workers was 430 μSv y(-1), which was lower than the intervention exemption level (1,000 μSv y(-1)) specified in ICRP Publication 82.

  13. Oxidative Stress and Role of Natural Plant Derived Antioxidants in Animal Reproduction

    Institute of Scientific and Technical Information of China (English)

    ZHONG Rong-zhen; ZHOU Dao-wei

    2013-01-01

    The experimental knowledge on the role of oxidative stress, and beneifcial and detrimental effects of plant derived antioxidants in male and female animal reproduction are reviewed in this article. Free radical-induced oxidative stress in animal reproduction causes great loss to livestock industry. Antioxidant therapy has been implicated to be effective in preventing diseases resulted from oxidative stress. Considering the advantages of lower side effects of natural antioxidants than those of synthetic antioxidants, plants or their extracts have been extensively utilized in animals. Although many advances have been gained on application of plant derived antioxidants in alleviating oxidative stress, debatable issues still exist. Because many opposite effects were observed even using plant extracts containing similar bioactive substances in the same animal species. Therefore, plant derived antioxidants, like free radicals, are“double-edged swords”in animal reproduction, representing that they may exhibit beneifcial or detrimental effects in animal reproduction, including spermatogenesis, semen functions, estrous cycles, ovulation, ovary functions, endometrium, embryo development, and pregnancy. Besides dose-dependent manner as an explanation of plant extracts’ dual function, future studies are needed to investigate the mechanism of double-edged actions of plant derived antioxidants in different animal reproduction systems.

  14. Enzymes from fungal and plant origin required for chemical diversification of insecticidal loline alkaloids in grass-Epichloë symbiota.

    Science.gov (United States)

    Pan, Juan; Bhardwaj, Minakshi; Nagabhyru, Padmaja; Grossman, Robert B; Schardl, Christopher L

    2014-01-01

    The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline), -NHCH3 (loline), -N(CH3)2 (N-methylloline), -N(CH3)Ac (N-acetylloline), -NHAc (N-acetylnorloline), and -N(CH3)CHO (N-formylloline). Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. Through isotopic labeling, we determined that N-acetylnorloline is the first fully cyclized loline alkaloid, implying that deacetylation, methylation, and acetylation steps are all involved in loline alkaloid diversification. Two genes of the loline alkaloid biosynthesis (LOL) gene cluster, lolN and lolM, were predicted to encode an N-acetamidase (deacetylase) and a methyltransferase, respectively. A knockout strain lacking both lolN and lolM stopped the biosynthesis at N-acetylnorloline, and complementation with the two wild-type genes restored production of N-formylloline and N-acetylloline. These results indicated that lolN and lolM are required in the steps from N-acetylnorloline to other lolines. The function of LolM as an N-methyltransferase was confirmed by its heterologous expression in yeast resulting in conversion of norloline to loline, and of loline to N-methylloline. One of the more abundant lolines, N-acetylloline, was observed in some but not all plants with symbiotic Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense) plants produced N-acetylloline, suggesting that a plant acetyltransferase catalyzes N-acetylloline formation. We conclude that although most loline alkaloid biosynthesis reactions are catalyzed by fungal enzymes, both fungal and plant enzymes are responsible for the

  15. Suppression of RNAi by dsRNA-degrading RNaseIII enzymes of viruses in animals and plants.

    Directory of Open Access Journals (Sweden)

    Isabel Weinheimer

    2015-03-01

    Full Text Available Certain RNA and DNA viruses that infect plants, insects, fish or poikilothermic animals encode Class 1 RNaseIII endoribonuclease-like proteins. dsRNA-specific endoribonuclease activity of the RNaseIII of rock bream iridovirus infecting fish and Sweet potato chlorotic stunt crinivirus (SPCSV infecting plants has been shown. Suppression of the host antiviral RNA interference (RNAi pathway has been documented with the RNaseIII of SPCSV and Heliothis virescens ascovirus infecting insects. Suppression of RNAi by the viral RNaseIIIs in non-host organisms of different kingdoms is not known. Here we expressed PPR3, the RNaseIII of Pike-perch iridovirus, in the non-hosts Nicotiana benthamiana (plant and Caenorhabditis elegans (nematode and found that it cleaves double-stranded small interfering RNA (ds-siRNA molecules that are pivotal in the host RNA interference (RNAi pathway and thereby suppresses RNAi in non-host tissues. In N. benthamiana, PPR3 enhanced accumulation of Tobacco rattle tobravirus RNA1 replicon lacking the 16K RNAi suppressor. Furthermore, PPR3 suppressed single-stranded RNA (ssRNA--mediated RNAi and rescued replication of Flock House virus RNA1 replicon lacking the B2 RNAi suppressor in C. elegans. Suppression of RNAi was debilitated with the catalytically compromised mutant PPR3-Ala. However, the RNaseIII (CSR3 produced by SPCSV, which cleaves ds-siRNA and counteracts antiviral RNAi in plants, failed to suppress ssRNA-mediated RNAi in C. elegans. In leaves of N. benthamiana, PPR3 suppressed RNAi induced by ssRNA and dsRNA and reversed silencing; CSR3, however, suppressed only RNAi induced by ssRNA and was unable to reverse silencing. Neither PPR3 nor CSR3 suppressed antisense-mediated RNAi in Drosophila melanogaster. These results show that the RNaseIII enzymes of RNA and DNA viruses suppress RNAi, which requires catalytic activities of RNaseIII. In contrast to other viral silencing suppression proteins, the RNaseIII enzymes are

  16. Enzymes from fungal and plant origin required for chemical diversification of insecticidal loline alkaloids in grass-Epichloe symbiota.

    Directory of Open Access Journals (Sweden)

    Juan Pan

    Full Text Available The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline, -NHCH3 (loline, -N(CH32 (N-methylloline, -N(CH3Ac (N-acetylloline, -NHAc (N-acetylnorloline, and -N(CH3CHO (N-formylloline. Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. Through isotopic labeling, we determined that N-acetylnorloline is the first fully cyclized loline alkaloid, implying that deacetylation, methylation, and acetylation steps are all involved in loline alkaloid diversification. Two genes of the loline alkaloid biosynthesis (LOL gene cluster, lolN and lolM, were predicted to encode an N-acetamidase (deacetylase and a methyltransferase, respectively. A knockout strain lacking both lolN and lolM stopped the biosynthesis at N-acetylnorloline, and complementation with the two wild-type genes restored production of N-formylloline and N-acetylloline. These results indicated that lolN and lolM are required in the steps from N-acetylnorloline to other lolines. The function of LolM as an N-methyltransferase was confirmed by its heterologous expression in yeast resulting in conversion of norloline to loline, and of loline to N-methylloline. One of the more abundant lolines, N-acetylloline, was observed in some but not all plants with symbiotic Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense plants produced N-acetylloline, suggesting that a plant acetyltransferase catalyzes N-acetylloline formation. We conclude that although most loline alkaloid biosynthesis reactions are catalyzed by fungal enzymes, both fungal and plant enzymes are responsible for

  17. Bilirubin oxidase-like proteins from Podospora anserina: promising thermostable enzymes for application in transformation of plant biomass.

    Science.gov (United States)

    Xie, Ning; Ruprich-Robert, Gwenaël; Silar, Philippe; Chapeland-Leclerc, Florence

    2015-03-01

    Plant biomass degradation by fungi is a critical step for production of biofuels, and laccases are common ligninolytic enzymes envisioned for ligninolysis. Bilirubin oxidases (BODs)-like are related to laccases, but their roles during lignocellulose degradation have not yet been fully investigated. The two BODs of the ascomycete fungus Podospora anserina were characterized by targeted gene deletions. Enzymatic assay revealed that the bod1(Δ) and bod2(Δ) mutants lost partly a thermostable laccase activity. A triple mutant inactivated for bod1, bod2 and mco, a previously investigated multicopper oxidase gene distantly related to laccases, had no thermostable laccase activity. The pattern of fruiting body production in the bod1(Δ) bod2(Δ) double mutant was changed. The bod1(Δ) and bod2(Δ) mutants were reduced in their ability to grow on ligneous and cellulosic materials. Furthermore, bod1(Δ) and bod2(Δ) mutants were defective towards resistance to phenolic substrates and H2 O2 , which may also impact lignocellulose breakdown. Double and triple mutants were more affected than single mutants, evidencing redundancy of function among BODs and mco. Overall, the data show that bod1, bod2 and mco code for non-canonical thermostable laccases that participate in the degradation of lignocellulose. Thanks to their thermal stability, these enzymes may be more promising candidate for biotechnological application than canonical laccases.

  18. PILOT PLANT STUDY ON NATURAL WATER COAGULANTS AS COAGULAN AIDS FOR WATER SUPPLY

    Directory of Open Access Journals (Sweden)

    B BINA

    2001-06-01

    Full Text Available Introduction: Natural plant coagulants have an important role to play in provision of portable water to rural communities in the developing world. The plant material that their coagulation properties have been confirmed in previous lab scale studies and can be found widely in Iran was selected as coagulant aids. Pilot plant study was done to evaluate the efficiency of natural material such as Starch/Gum Tragacanth, Fenugreek and Yeast as coagulant aids in conjunction with comercial alum. Methods: The pilot was placed in Isfahan Water Treatment Plant (IWTP and efficiency of these materials in removal of turbidity from raw water enters the IWTP was evaluated. The results indicated while these materials were used as coagulant aids in concentration of 1-5 mg/l conjunction with alum are able to reduced the turbidity and final residuals turbidity meets the standards limits. Results: The coagulation efficiency of these material were found to be effected by certain physico-chemical factors, namely, concentration of suspended solids, divalent cation metal and time of agitation. The relative importance of these variable was evaluated. The results of COD test proved that the natural coagulant aids in the optimum doses produce no any significant organic residual. Discussion: Economical considerations showed that using of these material as coagulant aids can cause reduction in alum consumption and in some cases are more econmical than synthetic polyelectrolyte.

  19. Natural genetic and induced plant resistance, as a control strategy to plant-parasitic nematodes alternative to pesticides.

    Science.gov (United States)

    Molinari, Sergio

    2011-03-01

    Plant-parasitic nematodes are pests of a wide range of economically important crops, causing severe losses to agriculture. Natural genetic resistance of plants is expected to be a valid solution of the many problems nematodes cause all over the world. Progress in resistance applications is particularly important for the less-developed countries of tropical and subtropical regions, since use of resistant cultivars may be the only possible and economically feasible control strategy in those farming systems. Resistance is being considered of particular importance also in modern high-input production systems of developed countries, as the customary reliance on chemical nematicides has been restricted or has come to an end. This review briefly describes the genetic bases of resistance to nematodes in plants and focuses on the chances and problems of its exploitation as a key element in an integrated management program. Much space is dedicated to the major problem of resistance durability, in that the intensive use of resistant cultivars is likely to increasingly induce the selection of virulent populations able to "break" the resistance. Protocols of pest-host suitability are described, as bioassays are being used to evaluate local nematode populations in their potential to be selected on resistant germplasm and endanger resistant crops. The recent progress in using robust and durable resistances against nematodes as an efficient method for growers in vegetable cropping systems is reported, as well as the possible use of chemicals that do not show any unfavorable impact on environment, to induce in plants resistance against plant-parasitic nematodes.

  20. Plant-derived natural products as sources of anti-quorum sensing compounds.

    Science.gov (United States)

    Koh, Chong-Lek; Sam, Choon-Kook; Yin, Wai-Fong; Tan, Li Ying; Krishnan, Thiba; Chong, Yee Meng; Chan, Kok-Gan

    2013-05-13

    Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms.

  1. Plant-Derived Natural Products as Sources of Anti-Quorum Sensing Compounds

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2013-05-01

    Full Text Available Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms.

  2. Host plants and natural enemies of Bemisia tabaci (Hemiptera: Aleyrodidae)in China

    Institute of Scientific and Technical Information of China (English)

    Shao-Jian Li; Xia Xue; Muhammad Z.Ahmed; Shun-Xiang Ren; Yu-Zhou Du; Jian-Hui Wu; Andrew G.S.Cuthbertson; Bao-Li Qiu

    2011-01-01

    The sweetpotato whitefly,Bemisia tabaci,has been a destructive pest in China for over the past two decades.It is an extremely polyphagous insect,being recorded feeding on hundreds of host plants around the world.Potential host plants and natural enemies of B.tabaci in the south,southeast,middle,north and northwest of China were investigated during the last decade.In total 361 plant species from 89 families were recorded in our surveys.Plants in the families Compositae,Cruciferae,Cucurbitaceae,Solanaceae and Leguminosae were the preferred host species for B.tabaci,which therefore suffered much damage from this devastating pest due to their high populations.In total,56 species of parasitoids,54 species of arthropod predators and seven species of entomopathogenic fungi were recorded in our surveys.Aphelinid parasitoids from Encarsia and Eretmocerus genera,lady beetles and lacewings in Coleoptera and Neuroptera were found to be the dominant arthropod predators of B.tabaci in China.The varieties of host plant,their distribution and the dominant species of natural enemies of B.tabaci in different regions of China are discussed.

  3. The localization within plant cells of enzymes involved in arginine biosynthesis.

    Science.gov (United States)

    Shargool, P D; Steeves, T; Weaver, M; Russell, M

    1978-04-01

    Studies were carried out to determine the distribution of the following: (1) carbamoyl phosphate synthetase (EC 2.7.2.9), (2) ornithine carbamoyltransferase (EC 2.1.3.3), (3) argininosuccinate synthetase (EC 6.3.4.5), and (4) argininosuccinate lyase (EC 4.3.2.1) in soybean cells grown in suspension culture. Protoplasts were produced from the soybean cells by treatment with cellulase (EC 3.2.1.4) and pectinase (EC 3.2.1.15); the protoplasts were then ruptured by osmotic shock with distilled water. This treatment was followed by differential centrifugation and sucrose density gradient centrifugation to isolate various organelle fractions including mitochondria and plastids. Examination of these fractions using specific enzyme assays showed that carbamoylphosphate synthetase and ornithine carbamoyltransferase were localized in a fraction found to be composed primarily of plastids. Argininosuccinate synthetase and argininosuccinate lyase appeared to be associated with either the cytosol or a membrane fraction in close association with the cytosol such as the endoplasmic reticulum or protoplast membrane.

  4. Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

    Directory of Open Access Journals (Sweden)

    Nur Shafika Mohd Sairazi

    2015-01-01

    Full Text Available 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.

  5. Genetic evidence for natural product mediated plant–plant allelopathy in rice

    Science.gov (United States)

    Xu, Meimei; Galhano, Rita; Wiemann, Philipp; Bueno, Emilio; Tiernan, Mollie; Wu, William; Chung, Ill-Min; Gershenzon, Jonathan; Tudzynski, Bettina; Sesma, Ane; Peters, Reuben J.

    2011-01-01

    Summary A role for specific natural products in directly mediating antagonistic plant–plant interactions –that is, allelopathy –has been controversial. If proven, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (Oryza sativa).However, while substantiated by the presence of phytotoxic compounds at potentially relevant levels, demonstrating a direct role for specific natural products in allelopathy has been difficult due to the chemical complexity of root and plant litter exudates. This complexity can be bypassed via selective genetic manipulation to ablate production of putative allelopathic compounds, but such an approach previously has not been applied.The rice diterpenoid momilactones provide an example of natural products for which correlative biochemical evidence has been obtained for a role in allelopathy. Here, we apply reverse genetics, using knock-outs of the relevant diterpene synthases (OsCPS4 and OsKSL4), to demonstrate that rice momilactones are involved in allelopathy, including suppressing growth of the widespread rice paddy weed, barnyard grass (Echinochloa crus-galli).Thus, our results not only provide novel genetic evidence for natural product mediated allelopathy, but also furnish a molecular target for breeding and metabolic engineering of this important crop plant. PMID:22150231

  6. Natural Circulation in Water Cooled Nuclear Power Plants Phenomena, models, and methodology for system reliability assessments

    Energy Technology Data Exchange (ETDEWEB)

    Jose Reyes

    2005-02-14

    In recent years it has been recognized that the application of passive safety systems (i.e., those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. In 1991 the IAEA Conference on ''The Safety of Nuclear Power: Strategy for the Future'' noted that for new plants the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate''.

  7. Air pollution and infant mortality: a natural experiment from power plant desulfurization.

    Science.gov (United States)

    Luechinger, Simon

    2014-09-01

    The paper estimates the effect of SO2 pollution on infant mortality in Germany, 1985-2003. To avoid endogeneity problems, I exploit the natural experiment created by the mandated desulfurization at power plants and power plants' location and prevailing wind directions, which together determine treatment intensity for counties. Estimates translate into an elasticity of 0.07-0.13 and the observed reduction in pollution implies an annual gain of 826-1460 infant lives. There is no evidence for disproportionate effects on neonatal mortality, but for an increase in the number of infants with comparatively low birth weight and length. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. [Proteolytic enzymes and trypsin inhibitors of higher plants under stress conditions].

    Science.gov (United States)

    Domash, V I; Sharpio, T P; Zabreĭko, S A; Sosnovskaia, T F

    2008-01-01

    The response of the components of a protease-inhibitor system of legume and cereal crops to stress factors was studied. It was found that salinization, heavy metal ions, and phytopathogenic flora inhibit the activity of neutral, acidic, and alkaline proteases at early stages of seed germination, the degree of the inhibition of the endoprotease activity being dependent on the index of tolerance of legume and cereal crops. It was shown that, in response to unfavorable conditions, accumulation of trypsin inhibitors occurs, which is accompanied by the appearance of new protein components, as indicated by electrophoresis. The results confirm the presumption that serine protease inhibitors are involved in the response of plants to stress factors.

  9. Herbaceous plant species invading natural areas tend to have stronger adaptive root foraging than other naturalized species.

    Science.gov (United States)

    Keser, Lidewij H; Visser, Eric J W; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

    2015-01-01

    Although plastic root-foraging responses are thought to be adaptive, as they may optimize nutrient capture of plants, this has rarely been tested. We investigated whether nutrient-foraging responses are adaptive, and whether they pre-adapt alien species to become natural-area invaders. We grew 12 pairs of congeneric species (i.e., 24 species) native to Europe in heterogeneous and homogeneous nutrient environments, and compared their foraging responses and performance. One species in each pair is a USA natural-area invader, and the other one is not. Within species, individuals with strong foraging responses, measured as plasticity in root diameter and specific root length, had a higher biomass. Among species, the ones with strong foraging responses, measured as plasticity in root length and root biomass, had a higher biomass. Our results therefore suggest that root foraging is an adaptive trait. Invasive species showed significantly stronger root-foraging responses than non-invasive species when measured as root diameter. Biomass accumulation was decreased in the heterogeneous vs. the homogeneous environment. In aboveground, but not belowground and total biomass, this decrease was smaller in invasive than in non-invasive species. Our results show that strong plastic root-foraging responses are adaptive, and suggest that it might aid in pre-adapting species to becoming natural-area invaders.

  10. Patch size and isolation predict plant species density in a naturally fragmented forest.

    Science.gov (United States)

    Munguía-Rosas, Miguel A; Montiel, Salvador

    2014-01-01

    Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the number of species be accurately predicted by habitat size and isolation. Therefore, species density could be better predicted by patch size and isolation in an ecosystem that has been fragmented for a very long time. We tested whether patch area, isolation and other spatial variables explain variation among forest patches in plant species density in an ecosystem where the forest has been naturally fragmented for long periods of time on a geological scale. Our main predictions were that plant species density will be positively correlated with patch size, and negatively correlated with isolation (distance to the nearest patch, connectivity, and distance to the continuous forest). We surveyed the vascular flora (except lianas and epiphytes) of 19 forest patches using five belt transects (50×4 m each) per patch (area sampled per patch = 0.1 ha). As predicted, plant species density was positively associated (logarithmically) with patch size and negatively associated (linearly) with patch isolation (distance to the nearest patch). Other spatial variables such as patch elevation and perimeter, did not explain among-patch variability in plant species density. The power of patch area and isolation as predictors of plant species density was moderate (together they explain 43% of the variation), however, a larger sample size may improve the explanatory power of these variables. Patch size and isolation may be suitable predictors of long-term plant species density in terrestrial ecosystems that are naturally and anthropogenically fragmented.

  11. Patch size and isolation predict plant species density in a naturally fragmented forest.

    Directory of Open Access Journals (Sweden)

    Miguel A Munguía-Rosas

    Full Text Available Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the number of species be accurately predicted by habitat size and isolation. Therefore, species density could be better predicted by patch size and isolation in an ecosystem that has been fragmented for a very long time. We tested whether patch area, isolation and other spatial variables explain variation among forest patches in plant species density in an ecosystem where the forest has been naturally fragmented for long periods of time on a geological scale. Our main predictions were that plant species density will be positively correlated with patch size, and negatively correlated with isolation (distance to the nearest patch, connectivity, and distance to the continuous forest. We surveyed the vascular flora (except lianas and epiphytes of 19 forest patches using five belt transects (50×4 m each per patch (area sampled per patch = 0.1 ha. As predicted, plant species density was positively associated (logarithmically with patch size and negatively associated (linearly with patch isolation (distance to the nearest patch. Other spatial variables such as patch elevation and perimeter, did not explain among-patch variability in plant species density. The power of patch area and isolation as predictors of plant species density was moderate (together they explain 43% of the variation, however, a larger sample size may improve the explanatory power of these variables. Patch size and isolation may be suitable predictors of long-term plant species density in terrestrial ecosystems that are naturally and anthropogenically fragmented.

  12. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Wintermans, Paul C A; Bakker, Peter A H M; Pieterse, Corné M J

    2016-04-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium. Here, we performed a genome-wide association (GWA) study on natural genetic variation in Arabidopsis for the ability to profit from rhizobacteria-mediated plant growth-promotion. To this end, 302 Arabidopsis accessions were tested for root architecture characteristics and shoot fresh weight in response to exposure to WCS417r. Although virtually all Arabidopsis accessions tested responded positively to WCS417r, there was a large variation between accessions in the increase in shoot fresh weight, the extra number of lateral roots formed, and the effect on primary root length. Correlation analyses revealed that the bacterially-mediated increase in shoot fresh weight is related to alterations in root architecture. GWA mapping for WCS417r-stimulated changes in root and shoot growth characteristics revealed 10 genetic loci highly associated with the responsiveness of Arabidopsis to the plant growth-promoting activity of WCS417r. Several of the underlying candidate genes have been implicated in important plant growth-related processes. These results demonstrate that plants possess natural genetic variation for the capacity to profit from the plant growth-promoting function of a beneficial rhizobacterium in their rhizosphere. This knowledge is a promising starting point for sustainable breeding strategies for future crops that are better able to maximize profitable functions from their root microbiome.

  13. THE EFFECT OF PLANT SPECIES ON SOME ENZYME ACTIVITIES OF THE SOIL OF A. Ü. Z. F. KENAN EVREN RESEARCH AND EXPERIMENTAL FARM

    Directory of Open Access Journals (Sweden)

    Sevinç ARCAK

    1999-01-01

    Full Text Available The objective of our study was to determine soil urease and ß-Glucosidase enzyme activities in soil samples taken from three different depths (0-5 cm, 5-15 cm and 15-30 cm and under different type of vegetation (apple, pine, clover, wheat and followed land. Highest activities, both urease and ß- Glucosidase were determined in soil samples representing parcels planted with clover. Enzyme activity showed increase in parcels which have high level of organic matter and total nitrogen. Urease enzyme activity was found higher than ß -Glucosidase activity in all samples. As the soil deepens, significant increase was monitored in urease activity (P

  14. Simple and robust determination of the activity signature of key carbohydrate metabolism enzymes for physiological phenotyping in model and crop plants

    DEFF Research Database (Denmark)

    Jammer, Alexandra; Gasperl, Anna; Luschin-Ebengreuth, Nora;

    2015-01-01

    The analysis of physiological parameters is important to understand the link between plant phenotypes and their genetic bases, and therefore is needed as an important element in the analysis of model and crop plants. The activities of enzymes involved in primary carbohydrate metabolism have been...... shown to be strongly associated with growth performance, crop yield, and quality, as well as stress responses. A simple, fast, and cost-effective method to determine activities for 13 key enzymes involved in carbohydrate metabolism has been established, mainly based on coupled spectrophotometric kinetic...

  15. Response of growth and antioxidant enzymes in Azolla plants (Azolla pinnata and Azolla filiculoides) exposed to UV-B.

    Science.gov (United States)

    Masood, Amjad; Zeeshan, M; Abraham, G

    2008-06-01

    Effect of ultravilolet-B (0.4 Wm(-2)) irradiation on growth, flavonoid content, lipid peroxidation, proline accumulation and activities of superoxide dismutase and peroxidase was comparatively analysed in Azolla pinnata and Azolla filiculoides. Growth measured as increment in dry weight reduced considerably due to all UV-B treatments. However, the reduction was found to be severe in A. filiculoides as compared to A. pinnata. The level of UV-absorbing compound flavonoids increased significantly in A. pinnata plants whereas only a slight increase in the flavonoid content was observed in A. filiculoides. UV-B exposure led to enhanced production of malondialdehyde (MDA) and electrolyte leakage in A. filiculoides than A. pinnata. Proline accumulation also showed a similar trend. Marked differences in the activity of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD) was noticed in both the plants exposed to UV-B. Our comparative studies indicate A. pinnata to be better tolerant to UV-B as compared with A. filiculoides which appears to be sensitive.

  16. Relative influence of plant quality and natural enemies on the seasonal dynamics of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton.

    Science.gov (United States)

    Asiimwe, Peter; Naranjo, Steven E; Ellsworth, Peter C

    2013-06-01

    The abundance and distribution of insect herbivores is determined by, among other things, plant quality and natural enemies. These two factors vary temporally and spatially, subsequently affecting seasonal population dynamics. The relative influence of plant quality and natural enemies on the seasonal dynamics of Bemisia tabaci (Gennadius) was investigated in a 3-yr field study in cotton. Plant quality was manipulated through varying irrigation regimes: irrigations done at 20, 40, and 60% soil water depletions; and natural enemy densities were manipulated using broad spectrum insecticide applications that reduced their densities compared with unsprayed controls. In each year, densities of B. tabaci eggs, large nymphs and adults were consistently higher when natural enemy densities were reduced compared with when they were left unaltered, regardless of irrigation regime. In contrast, effects of plant quality on densities of all whitefly stages were weak and inconsistent. In addition, natural enemy densities and predator:prey ratios also were not generally affected by plant quality. Interactions between natural enemies and plant quality on whitefly dynamics were rare. In general, whitefly densities were elevated two-thirds of the time and increased two- to sixfold when natural enemy densities were reduced compared with plant quality effects which influenced whitefly densities about one-third of the time and were expressed inconsistently over the years. This indicates that natural enemies exert a comparatively greater influence on seasonal dynamics of B. tabaci in cotton than plant quality, as manipulated by differential irrigation.

  17. Synergistic effect of chickpea plants and Mesorhizobium as a natural system for chromium phytoremediation.

    Science.gov (United States)

    Velez, Pilar A; Talano, Melina A; Paisio, Cintia E; Agostini, Elizabeth; González, Paola S

    2017-09-01

    The presence of chromium in soils not only affects the physiological processes of plants but also the microbial rhizosphere composition and metabolic activities of microorganisms. Hence, the inoculation of plants with Cr(VI)-tolerant rhizospheric microorganisms as an alternative to reduce Cr phytotoxicity was studied. In this work, chickpea germination was reduced by Cr(VI) concentrations of 150 and 250 mg/L (6 and 33%, respectively); however lower Cr(VI) concentrations negatively affected the biomass. On the other hand, its symbiont, Mesorhizobium ciceri, was able to grow and remove different Cr(VI) concentrations (5-20 mg/L). The inoculation of chickpea plants with this strain exposed to Cr(VI) showed a significantly enhanced plant growth. In addition, inoculated plants accumulated higher Cr concentration in roots than those noninoculated. It is important to note that Cr was not translocated to shoots independently of inoculation. These results suggest that Mesorhizobium's capability to remove Cr(VI) could be exploited for bioremediation. Moreover, chickpea plants would represent a natural system for phytoremediation or phytostabilization of Cr in situ that could be improved with M. ciceri inoculation. This strategy would be considered as a phytoremediation tool with great economic and ecological relevance.

  18. Recent advances in natural products from plants for treatment of liver diseases.

    Science.gov (United States)

    Zhang, Aihua; Sun, Hui; Wang, Xijun

    2013-05-01

    Liver disease is any condition that may cause liver inflammation or tissue damage and affects liver function. Natural products that are found in vegetables, fruits, plant extracts, herbs, insects, and animals, have been traditionally used for treating liver diseases. They are chemical compounds that usually have biological activities for use in drug discovery and design. Many natural products have been clinically available as potent hepatoprotective agents against commonly occurring liver diseases. This review summarizes the current progress in the basic, clinical, and translational research on natural products in treatment of various liver diseases. Furthermore, we will focus on the discovery and biological evaluation of the natural products, which shows potential as a new therapeutic agent of liver diseases.

  19. Bioinformatics Evaluation of Plant Chlorophyllase, the Key Enzyme in Chlorophyll Degradation

    Directory of Open Access Journals (Sweden)

    Ebrahim Sharafi

    2017-06-01

    Full Text Available Background and Objective: Chlorophyllase catalyzes the hydrolysis of chlorophylls to chlorophyllide and phytol. Recently, several applications including removal of chlorophylls from vegetable oils, use in laundry detergents and production of chlorophyllides have been described for chlorophyllase. However, there is little information about the biochemical characteristics of chlorophyllases.Material and Methods: 35 chlorophyllase protein sequences were obtained from the National Centre for Biotechnology Information database. All of the sequences were analyzed using bioinformatics tools for their conserved domain, phylogenetic relationships and biochemical characteristics.Results and Conclusion: The overall domain architecture of chlorophyllases consisted of the esterases/lipases superfamily domain over their full length and the alpha/beta hydrolase family domain over the middle part of their sequences. Plant chlorophyllases could be classified into 4 clades. Molecular weight and pI of the chlorophyllases ranged 32.65-37.77 kDa and 4.80-8.97, respectively. The most stable chlorophyllase is probably obtained from Malus domestica. Chlorophyllases form Solanum pennellii, Triticum aestivum, Triticum urartu, Arabidopsis lyrata, Pachira macrocarpa, Prunus mume and Malus domestica were predicted to be soluble upon overexpression in Escherichia coli, Beta vulgaris and Chenopodium album chlorophyllases were predicted to form no disulfide bond. Chlorophyllases from Jatropha curcas, Amborella trichopod, Setaria italica, Piper betle, Triticum urartu and Arabidopsis thaliana were predicted to be in non-N-glycosylated form.Conflict of interest: The authors declare no conflict of interest.

  20. Study on the Current Situation and Protection Countermeasures of Wild Plant Resources in Xishuangbanna National Nature Reserve

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the current situation and protection countermeasures of wild plant resources in Xishuangbanna National Nature Reserve. [Method] The current situation of wild plant resources in Xishuangbanna National Nature Reserve was researched by means of route survey, sample plot survey and literature survey, and then the main impact factors of wild plant resources were analyzed by using participatory rural appraisal and problem tree analysis, finally protection countermeasures were put ...

  1. Validation of a plant dynamics code for 4S - Test analysis of natural circulation behavior

    Energy Technology Data Exchange (ETDEWEB)

    Sebe, F.; Horie, H.; Matsumiya, H. [Toshiba Corporation, 8 Shinsugita-Cho, Isogo-Ku, Yokohama, 235-8523 (Japan); Fanning, T. H. [Argonne National Laboratory, 9700 S Cass Ave, Argonne, IL 60439 (United States)

    2012-07-01

    A plant transient dynamics code for a sodium-cooled fast reactor was developed by Toshiba. The code is used to evaluate the safety performance of Super-Safe, Small, and Simple reactor (4S) for Anticipated Operational Occurrences (AOOs), Design Basis Accident (DBA) and Beyond DBA (BDBA). The code is currently undergoing verification and validation (V and V). As one of the validation, test analysis of the Shutdown Heat Removal Test (SHRT)-17 performed in the Experimental Breeder Reactor (EBR)-II was conducted. The SHRT-17 is protected loss of flow test. The purpose of this validation is to confirm capability of the code to simulate natural circulation behavior of the plant. As a result, good agreements are shown between the analytical results and the measured data which were available from instrumented subassembly. The detailed validation result of the natural circulation behavior is described in this paper. (authors)

  2. Development of an equine coronavirus-specific enzyme-linked immunosorbent assay to determine serologic responses in naturally infected horses.

    Science.gov (United States)

    Kooijman, Lotte J; Mapes, Samantha M; Pusterla, Nicola

    2016-07-01

    Equine coronavirus (EqCoV) infection has been documented in most reports through quantitative qPCR analysis of feces and viral genome sequencing. Although qPCR is used to detect antigen during the acute disease phase, there is no equine-specific antibody test available to study EqCoV seroprevalence in various horse populations. We developed an enzyme-linked immunosorbent assay (ELISA) targeting antibodies to the spike (S) protein of EqCoV and validated its use, using acute and convalescent sera from 83 adult horses involved in 6 outbreaks. The EqCoV S protein-based ELISA was able to reliably detect antibodies to EqCoV in naturally infected horses. The greatest seroconversion rate was observed in horses with clinical signs compatible with EqCoV infection and EqCoV qPCR detection in feces. The EqCoV S protein-based ELISA could be used effectively for seroepidemiologic studies in order to better characterize the overall infection rate of EqCoV in various horse populations.

  3. Wall extensibility: its nature, measurement and relationship to plant cell growth

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    Expansive growth of plant cells is controlled principally by processes that loosen the wall and enable it to expand irreversibly. The central role of wall relaxation for cell expansion is reviewed. The most common methods for assessing the extension properties of plant cell walls ( wall extensibility') are described, categorized and assessed critically. What emerges are three fundamentally different approaches which test growing cells for their ability (a) to enlarge at different values of turgor, (b) to induce wall relaxation, and (c) to deform elastically or plastically in response to an applied tensile force. Analogous methods with isolated walls are similarly reviewed. The results of these different assays are related to the nature of plant cell growth and pertinent biophysical theory. I argue that the extensibilities' measured by these assays are fundamentally different from one another and that some are more pertinent to growth than others.

  4. Process synthesis for natural products from plants based on PAT methodology

    DEFF Research Database (Denmark)

    2017-01-01

    generates different process flowsheet alternatives consisting of multiple separation techniques. Decision making is supported by heuristics as well as basic process information already available from previous studies. In addition, process analytical technology (PAT) framework, a part of Quality by Design...... (QbD) approach, has been included at various steps to obtain molecular level information of process streams and thereby, support the rational decision making. The formulated methodology has been used to isolate and purify artemisinin, an antimalarial drug, from dried leaves of the plant Artemisia...... and other consumer products. Therefore, process technology towards industrial scale production of such high value chemicals from plants has significant importance. In this chapter, a process synthesis methodology for recovery of natural products from plants at conceptual level is discussed. The methodology...

  5. Air Pollution and Infant Mortality: A Natural Experiment from Power Plant Desulfurization

    OpenAIRE

    Lüchinger, Simon

    2010-01-01

    The paper estimates the effect of SO2 pollution on infant mortality in Germany, 1985-2003. To avoid simultaneity problems, I exploit the natural experiment created by the mandated desulfurization at power plants, with wind directions dividing counties into treatment and control groups. Instrumental variable estimates are larger than conventional estimates and translate into an elasticity of 0.08-0.13. The observed reduction in pollution implies an annual gain of 895-1528 infant lives. Estimat...

  6. 天然植物染发剂%The Natural Plant Hair-dying

    Institute of Scientific and Technical Information of China (English)

    穆伟伟; 李志洲

    2015-01-01

    Starting from the structure and composition of hair, the mechanism of hair dye was summarized and the hair dye was classified again. Meanwhile, the chemical composition of hair dyes and natural plant hair dye were compared, the emphasis was on the great advantages of natural plant hair dye and development prospects. The present development of natural plant hair dye and application technology of breakthrough and innovation was focused on. In addition, the sensitization of hair dye was analyzed and a considerable solution was put forward. Finally, the development of natural plant hair dye was put on the technical field of great expectations and support.%从头发的结构和组成出发,总结染发剂的作用机理并对染发剂进行再次分类;同时将化学合成类染发剂与天然植物类染发剂进行比较,着重突出了天然植物染发剂的巨大优势及发展前景;重点阐述了天然植物染发剂的发展现状及其应用技术上的突破和革新,另外对于染发剂的致敏性进行分析,并提出了可观的解决方案和思路。最后,对天然植物染发剂在技术领域上的发展寄予厚望和支持。

  7. Control of Cowpea Weevil, Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae), Using Natural Plant Products

    OpenAIRE

    Bamphitlhi Tiroesele; Kesegofetse Thomas; Seipati Seketeme

    2014-01-01

    A laboratory study was conducted to investigate the effects of natural products on the reproduction and damage of Callosobruchus maculatus, the cowpea weevil, on cowpea seeds at Botswana College of Agriculture in Gaborone, Botswana. The cowpea variety Blackeye was used in the study. Fifty grams of each plant product (garlic, peppermint and chilies) was added to 500 g of the cowpea seeds. Findings of this experiment revealed that chilies and garlic had negative effects on cowpea weevils for al...

  8. Genetic variation in plant volatile emission does not result in differential attraction of natural enemies in the field.

    Science.gov (United States)

    Wason, Elizabeth L; Hunter, Mark D

    2014-02-01

    Volatile organic chemical (VOC) emission by plants may serve as an adaptive plant defense by attracting the natural enemies of herbivores. For plant VOC emission to evolve as an adaptive defense, plants must show genetic variability for the trait. To date, such variability has been investigated primarily in agricultural systems, yet relatively little is known about genetic variation in VOCs emitted by natural populations of native plants. Here, we investigate intraspecific variation in constitutive and herbivore-induced plant VOC emission using the native common milkweed plant (Asclepias syriaca) and its monarch caterpillar herbivore (Danaus plexippus) in complementary field and common garden greenhouse experiments. In addition, we used a common garden field experiment to gauge natural enemy attraction to milkweed VOCs induced by monarch damage. We found evidence of genetic variation in the total constitutive and induced concentrations of VOCs and the composition of VOC blends emitted by milkweed plants. However, all milkweed genotypes responded similarly to induction by monarchs in terms of their relative change in VOC concentration and blend. Natural enemies attacked decoy caterpillars more frequently on damaged than on undamaged milkweed, and natural enemy visitation was associated with higher total VOC concentrations and with VOC blend. Thus, we present evidence that induced VOCs emitted by milkweed may function as a defense against herbivores. However, plant genotypes were equally attractive to natural enemies. Although milkweed genotypes diverge phenotypically in their VOC concentrations and blends, they converge into similar phenotypes with regard to magnitude of induction and enemy attraction.

  9. Evolved Control of Natural Plants: Crossing the Reality Gap for User-Defined Steering of Growth and Motion

    DEFF Research Database (Denmark)

    Hofstadler, Daniel Nicolas; Wahby, Mostafa; Heinrich, Mary Katherine

    2017-01-01

    Mixing societies of natural and artificial systems can provide interesting and potentially fruitful research targets. Here we mix robotic setups and natural plants in order to steer the motion behavior of plants while growing. The robotic setup uses a camera to observe the plant and uses a pair...... of light sources to trigger phototropic response, steering the plant to user-defined targets. An evolutionary robotic approach is used to design a controller for the setup. Initially, preliminary experiments are performed with a simple predetermined controller and a growing bean plant. The plant behavior...... in response to the simple controller is captured by image processing, and a model of the plant tip dynamics is developed. The model is used in simulation to evolve a robot controller that steers the plant tip such that it follows a number of randomly generated target points. Finally, we test the simulation...

  10. Natural radionuclides in waste water discharged from coal-fired power plants in Serbia.

    Science.gov (United States)

    Janković, Marija M; Todorović, Dragana J; Sarap, Nataša B; Krneta Nikolić, Jelena D; Rajačić, Milica M; Pantelić, Gordana K

    2016-12-01

    Investigation of the natural radioactivity levels in water around power plants, as well as in plants, coal, ash, slag and soil, and to assess the associated radiation hazard is becoming an emerging and interesting topic. This paper is focused on the results of the radioactivity analysis in waste water samples from five coal-fired power plants in Serbia (Nikola Tesla A, Nikola Tesla B, Kolubara, Morava and Kostolac), which were analyzed in the period 2003-2015. River water samples taken upstream and downstream from the power plants, drain water and overflow water were analyzed. In the water samples gamma spectrometry analysis was performed as well as determination of gross alpha and beta activity. Natural radionuclide (40)K was detected by gamma spectrometry, while the concentrations of other radionuclides, (226)Ra, (235)U and (238)U, usually were below the minimum detection activity (MDA). (232)Th and artificial radionuclide (137)Cs were not detected in these samples. Gross alpha and beta activities were determined by the α/β low level proportional counter Thermo Eberline FHT 770 T. In the analyzed samples, gross alpha activity ranged from MDA to 0.47 Bq L(-)(1), while the gross beta activity ranged from MDA to 1.55 Bq L(-)(1).

  11. Bacterial and plant HAD enzymes catalyse a missing phosphatase step in thiamin diphosphate biosynthesis.

    Science.gov (United States)

    Hasnain, Ghulam; Roje, Sanja; Sa, Na; Zallot, Rémi; Ziemak, Michael J; de Crécy-Lagard, Valérie; Gregory, Jesse F; Hanson, Andrew D

    2016-01-15

    The penultimate step of thiamin diphosphate (ThDP) synthesis in plants and many bacteria is dephosphorylation of thiamin monophosphate (ThMP). Non-specific phosphatases have been thought to mediate this step and no genes encoding specific ThMP phosphatases (ThMPases) are known. Comparative genomic analysis uncovered bacterial haloacid dehalogenase (HAD) phosphatase family genes (from subfamilies IA and IB) that cluster on the chromosome with, or are fused to, thiamin synthesis genes and are thus candidates for the missing phosphatase (ThMPase). Three typical candidates (from Anaerotruncus colihominis, Dorea longicatena and Syntrophomonas wolfei) were shown to have efficient in vivo ThMPase activity by expressing them in an Escherichia coli strain engineered to require an active ThMPase for growth. In vitro assays confirmed that these candidates all preferred ThMP to any of 45 other phosphate ester substrates tested. An Arabidopsis thaliana ThMPase homologue (At4g29530) of unknown function whose expression pattern and compartmentation fit with a role in ThDP synthesis was shown to have in vivo ThMPase activity in E. coli and to prefer ThMP to any other substrate tested. However, insertional inactivation of the At4g29530 gene did not affect growth or the levels of thiamin or its phosphates, indicating that Arabidopsis has at least one other ThMPase gene. The Zea mays orthologue of At4g29530 (GRMZM2G035134) was also shown to have ThMPase activity. These data identify HAD genes specifying the elusive ThMPase activity, indicate that ThMPases are substrate-specific rather than general phosphatases and suggest that different evolutionary lineages have recruited ThMPases independently from different branches of the HAD family.

  12. Comparison of detergent and protease enzyme combinations for the detection of scrapie-associated fibrils from the central nervous system of sheep naturally affected with scrapie.

    Science.gov (United States)

    Stack, M J; Aldrich, A M; Davis, L A

    1997-02-01

    Standardized samples of tissue from the central nervous system of four sheep naturally affected with scrapie and from four healthy control sheep were subjected to a centrifugal extraction technique used to obtain scrapie-associated fibrils; the latter were then demonstrated by negative-contrast transmission electron microscopy. This regime was used to evaluate the fibril yield obtained from the 25 possible combinations of five different detergents and five different proteolytic enzymes. N-lauroylsarcosine detergent was found to be the most efficient detergent for all five enzymes, followed by sulphabetaine 3-14. Sodium dodecyl sulphate detergent was successful only in combination with a subtilisin Carlsberg enzyme. Octylglucoside and nonidet P40 detergents did not produce fibrils with any of the enzymes. Proteinase K was the least efficient of the five enzymes when used in combination with N-lauroylsarcosine; subtilisin Carlsberg, clostripain, pronase and trypsin enzymes all gave higher fibril yields. A combination of N-lauroylsarcosine detergent and subtilisin Carlsberg proteolytic enzyme gave the highest fibril yield.

  13. Effects of Different Levels of Water Stress on Leaf Water Potential, Stomatal Resistance, Protein and Chlorophyll Content and Certain Anti-oxidative Enzymes in Tomato Plants

    Institute of Scientific and Technical Information of China (English)

    Hatem Zgallai; Kathy Steppe; Raoul Lemeur

    2006-01-01

    A greenhouse experiment was performed in order to investigate the effects of different levels of water stress on leaf water potential (ψw), stomatal resistance (rs), protein content and chlorophyll (Chi) content of tomato plants (Lycopersicon esculentum Mill. cv. Nikita). Water stress was induced by adding polyethylene glycol (PEG 6 000) to the nutrient solution to reduce the osmotic potential (ψs). We investigated the behavior of anti-oxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD), during the development of water stress. Moderate and severe water stress (i.e.ψs= -0.51 and -1.22 MPa, respectively) caused a decrease in ψw for all treated (water-stressed) plants compared with control plants, with the reduction being more pronounced for severely stressed plants. In addition, rs was significantly affected by the induced water stress and a decrease in leaf soluble proteins and Chi content was observed. Whereas CAT activity remained constant, SOD activity was increased in water-stressed plants compared with unstressed plants. These results indicate the possible role of SOD as an anti-oxidant protector system for plants under water stress conditions. Moreover, it suggests the possibility of using this enzyme as an additional screening criterion for detecting water stress in plants.

  14. Continuous plant cell perfusion culture: bioreactor characterization and secreted enzyme production.

    Science.gov (United States)

    Su, Wei Wen; Arias, Renee

    2003-01-01

    Culture perfusion is widely practiced in mammalian cell processes to enhance secreted antibody production. Here, we report the development of an efficient continuous perfusion process for the cultivation of plant cell suspensions. The key to this process is a perfusion bioreactor that incorporates an annular settling zone into a stirred-tank bioreactor to achieve continuous cell/medium separation via gravitational sedimentation. From washout experiments, we found that under typical operating conditions (e.g., 200 rpm and 0.3 vvm) the liquid phase in the entire perfusion bioreactor was homogeneous despite the presence of the cylindrical baffle. Using secreted acid phosphatase (APase) produced in Anchusa officinalis cell culture as a model we have studied the perfusion cultures under complete or partial cell retention. The perfusion culture was operated under phosphate limitation to stimulate APase production. Successful operation of the perfusion process over four weeks has been achieved in this work. When A. officinalis cells were grown in the perfusion reactor and perfused at up to 0.4 vvd with complete cell retention, a cell dry weight exceeding 20 g/l could be achieved while secreted APase productivity leveled off at approximately 300 units/l/d. The culture became extremely dense with the maximum packed cell volume (PCV) surpassing 70%. In comparison, the maximum cell dry weight and overall secreted APase productivity in a typical batch culture were 10-12 g/l and 100-150 units/l/d, respectively. Operation of the perfusion culture under extremely high PCV for a prolonged period, however, led to declined oxygen uptake and reduced viability. Subsequently, cell removal via a bleed stream at up to 0.11 vvd was tested and shown to stabilize the culture at a PCV below 60%. With culture bleeding, both specific oxygen uptake rate and viability were shown to increase. This also led to a higher cell dry weight exceeding 25 g/l, and further improvement of secreted APase

  15. Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel; McDonald, Bradon R.; Nicora, Carrie D.; Wu, Si; Moore, Ronald J.; Orton, Daniel J.; Monroe, Matthew E.; Piehowski, Paul D.; Purvine, Samuel O.; Smith, Richard D.; Lipton, Mary S.; Burnum-Johnson, Kristin E.; Currie, Cameron R.

    2015-08-28

    Leaf-cutter ants are prolific and conspicuous Neotropical herbivores that derive energy from specialized fungus gardens they cultivate using foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain lignocellulases that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as it is foraged by the ants. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous lignocellulases likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three-quarters of all lignocellulases identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 23 lignocellulases enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

  16. Overproduction of C4 photosynthetic enzymes in transgenic rice plants: an approach to introduce the C4-like photosynthetic pathway into rice.

    Science.gov (United States)

    Taniguchi, Yojiro; Ohkawa, Hiroshi; Masumoto, Chisato; Fukuda, Takuya; Tamai, Tesshu; Lee, Kwanghong; Sudoh, Sizue; Tsuchida, Hiroko; Sasaki, Haruto; Fukayama, Hiroshi; Miyao, Mitsue

    2008-01-01

    Four enzymes, namely, the maize C(4)-specific phosphoenolpyruvate carboxylase (PEPC), the maize C(4)-specific pyruvate, orthophosphate dikinase (PPDK), the sorghum NADP-malate dehydrogenase (MDH), and the rice C(3)-specific NADP-malic enzyme (ME), were overproduced in the mesophyll cells of rice plants independently or in combination. Overproduction individually of PPDK, MDH or ME did not affect the rate of photosynthetic CO(2) assimilation, while in the case of PEPC it was slightly reduced. The reduction in CO(2) assimilation in PEPC overproduction lines remained unaffected by overproduction of PPDK, ME or a combination of both, however it was significantly restored by the combined overproduction of PPDK, ME, and MDH to reach levels comparable to or slightly higher than that of non-transgenic rice. The extent of the restoration of CO(2) assimilation, however, was more marked at higher CO(2) concentrations, an indication that overproduction of the four enzymes in combination did not act to concentrate CO(2) inside the chloroplast. Transgenic rice plants overproducing the four enzymes showed slight stunting. Comparison of transformants overproducing different combinations of enzymes indicated that overproduction of PEPC together with ME was responsible for stunting, and that overproduction of MDH had some mitigating effects. Possible mechanisms underlying these phenotypic effects, as well as possibilities and limitations of introducing the C(4)-like photosynthetic pathway into C(3) plants, are discussed.

  17. Inhibition of key enzymes linked to obesity by preparations from Mediterranean dietary plants: effects on α-amylase and pancreatic lipase activities.

    Science.gov (United States)

    2013-12-01

    One of the most important strategy in the treatment of obesity includes the development of nutrient digestion and absorption inhibitors. Inhibition of digestive enzymes is one of the most widely studied mechanisms used to determine the potential efficacy of natural products as hypolipidemic and hypoglycaemic agents. In vitro studies here reported were performed to evaluate the inhibitory activity of five species(as hydroalcoholic extracts) of edible plants from Calabria region (Italy) on amylase and lipase by monitoring the hydrolysis of p-NPC and the hydrolysis of glycoside bonds indigestible carbohydrate foods. The formulation obtained from Clematis vitalba L. exhibited the strongest inhibitory effect on pancreatic lipase (IC50=0.99 mg/ml) and on α-amylase(IC50=31.52 μg/ml). In order to explore metabolome production HPTLC analysis of the extracts was performed, revealing the predominance of (±)-catechin, caffeic acid and chlorogenic acid in C. vital ba formulation at concentration of 23.18±3.14,13.63±0.65 and 18.88±0.76 mg/g, respectively. GC/MS analysis was used to identify fatty acids and terpene composition.

  18. Coupled high-throughput functional screening and next generation sequencing for identification of plant polymer decomposing enzymes in metagenomic libraries.

    Science.gov (United States)

    Nyyssönen, Mari; Tran, Huu M; Karaoz, Ulas; Weihe, Claudia; Hadi, Masood Z; Martiny, Jennifer B H; Martiny, Adam C; Brodie, Eoin L

    2013-01-01

    Recent advances in sequencing technologies generate new predictions and hypotheses about the functional roles of environmental microorganisms. Yet, until we can test these predictions at a scale that matches our ability to generate them, most of them will remain as hypotheses. Function-based mining of metagenomic libraries can provide direct linkages between genes, metabolic traits and microbial taxa and thus bridge this gap between sequence data generation and functional predictions. Here we developed high-throughput screening assays for function-based characterization of activities involved in plant polymer decomposition from environmental metagenomic libraries. The multiplexed assays use fluorogenic and chromogenic substrates, combine automated liquid handling and use a genetically modified expression host to enable simultaneous screening of 12,160 clones for 14 activities in a total of 170,240 reactions. Using this platform we identified 374 (0.26%) cellulose, hemicellulose, chitin, starch, phosphate and protein hydrolyzing clones from fosmid libraries prepared from decomposing leaf litter. Sequencing on the Illumina MiSeq platform, followed by assembly and gene prediction of a subset of 95 fosmid clones, identified a broad range of bacterial phyla, including Actinobacteria, Bacteroidetes, multiple Proteobacteria sub-phyla in addition to some Fungi. Carbohydrate-active enzyme genes from 20 different glycoside hydrolase (GH) families were detected. Using tetranucleotide frequency (TNF) binning of fosmid sequences, multiple enzyme activities from distinct fosmids were linked, demonstrating how biochemically-confirmed functional traits in environmental metagenomes may be attributed to groups of specific organisms. Overall, our results demonstrate how functional screening of metagenomic libraries can be used to connect microbial functionality to community composition and, as a result, complement large-scale metagenomic sequencing efforts.

  19. Coupled high-throughput functional screening and next generation sequencing for identification of plant polymer decomposing enzymes in metagenomic libraries

    Directory of Open Access Journals (Sweden)

    Mari eNyyssönen

    2013-09-01

    Full Text Available Recent advances in sequencing technologies generate new predictions and hypotheses about the functional roles of environmental microorganisms. Yet, until we can test these predictions at a scale that matches our ability to generate them, most of them will remain as hypotheses. Function-based mining of metagenomic libraries can provide direct linkages between genes, metabolic traits and microbial taxa and thus bridge this gap between sequence data generation and functional predictions. Here we developed high-throughput screening assays for function-based characterization of activities involved in plant polymer decomposition from environmental metagenomic libraries. The multiplexed assays use fluorogenic and chromogenic substrates, combine automated liquid handling and use a genetically modified expression host to enable simultaneous screening of 12,160 clones for 14 activities in a total of 170,240 reactions. Using this platform we identified 374 (0.26 % cellulose, hemicellulose, chitin, starch, phosphate and protein hydrolyzing clones from fosmid libraries prepared from decomposing leaf litter. Sequencing on the Illumina MiSeq platform, followed by assembly and gene prediction of a subset of 95 fosmid clones, identified a broad range of bacterial phyla, including Actinobacteria, Bacteroidetes, multiple Proteobacteria sub-phyla in addition to some Fungi. Carbohydrate-active enzyme genes from 20 different glycoside hydrolase families were detected. Using tetranucleotide frequency binning of fosmid sequences, multiple enzyme activities from distinct fosmids were linked, demonstrating how biochemically-confirmed functional traits in environmental metagenomes may be attributed to groups of specific organisms. Overall, our results demonstrate how functional screening of metagenomic libraries can be used to connect microbial functionality to community composition and, as a result, complement large-scale metagenomic sequencing efforts.

  20. Mercury localization and speciation in plants grown hydroponically or in a natural environment.

    Science.gov (United States)

    Carrasco-Gil, Sandra; Siebner, Hagar; Leduc, Danika L; Webb, Samuel M; Millán, Rocío; Andrews, Joy C; Hernández, Luis E

    2013-04-01

    Better understanding of mercury (Hg) accumulation, distribution, and speciation in plants is required to evaluate potential risks for the environment and to optimize phytostabilization strategies for Hg-contaminated soils. The behavior of Hg in alfalfa (Medicago sativa) plants grown under controlled conditions in a hydroponic system (30 μM HgCl2) was compared with that of naturally occurring Horehound (Marrubium vulgare) plants collected from a mining soil polluted with Hg (Almadenejos, Spain) to characterize common mechanisms of tolerance. Synchrotron X-ray Fluorescence microprobe (μ-SXRF) showed that Hg accumulated at the root apex of alfalfa and was distributed through the vascular system to the leaves. Transmission electron microscopy (TEM) implied association of Hg with cell walls, accompanied by their structural changes, in alfalfa roots. Extended X-ray absorption fine structure (EXAFS) determined that Hg was principally bound to biothiols and/or proteins in M. sativa roots, stems, and leaves. However, the major fraction of Hg detected in M. vulgare plants consisted of mineral species, possibly associated with soil components. Interestingly, the fraction of Hg bound to biothiols/proteins (i.e., metabolically processed Hg) in leaves of both plants (alfalfa and M. vulgare) was similar, in spite of the big difference in Hg accumulation in roots, suggesting that some tolerance mechanisms might be shared.

  1. Beyond the ecological: biological invasions alter natural selection on a native plant species.

    Science.gov (United States)

    Lau, Jennifer A

    2008-04-01

    Biological invasions can have strong ecological effects on native communities by altering ecosystem functions, species interactions, and community composition. Even though these ecological effects frequently impact the population dynamics and fitness of native species, the evolutionary consequences of biological invasions have received relatively little attention. Here, I show that invasions impose novel selective pressures on a native plant species. By experimentally manipulating community composition, I found that the exotic plant Medicago polymorpha and the exotic herbivore Hypera brunneipennis alter the strength and, in some instances, the direction of natural selection on the competitive ability and anti-herbivore defenses of the native plant Lotus wrangelianus. Furthermore, the community composition of exotics influenced which traits were favored. For example, high densities of the exotic herbivore Hypera selected for increased resistance to herbivores in the native Lotus; however, when Medicago also was present, selection on this defense was eliminated. In contrast, selection on tolerance, another plant defense trait, was highest when both Hypera and Medicago were present at high densities. Thus, multiple exotic species may interact to influence the evolutionary trajectories of native plant populations, and patterns of selection may change as additional exotic species invade the community.

  2. Adaptive transgenerational plasticity in plants: case studies, mechanisms, and implications for natural populations

    Directory of Open Access Journals (Sweden)

    Jacob J. Herman

    2011-12-01

    Full Text Available Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights.

  3. Species diversity of plant communities from territories with natural origin radionuclides contamination

    Energy Technology Data Exchange (ETDEWEB)

    Kaneva, A.V.; Belykh, E.S.; Maystrenko, T.A.; Grusdev, B.I.; Zainullin, V.G.; Vakhrusheva, O.M. [Institute of Biology, Komi Scientific Center, Ural Division of RAS, Syktyvkar, 167982 (Russian Federation); Oughton, D. [Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Aas (Norway)

    2014-07-01

    Since plants dominate every landscape, the impact of any environmental stressor on plants can directly affect the structure and function of an ecosystem, resulting in decreased primary productivity and degradation of wildlife habitat. The investigation goal of the present research was to study how vascular plant species' composition at a former radium mining site could be related to i) soil contamination with heavy metals and uranium and thorium decay chain radionuclides and ii) soil agrochemical properties. Between the 1930's and 1950's, the commercial extraction of radium, storage of the uranium mill tailings and radium production wastes, together with deactivation of the site with a mixture of sand and gravel completely destroyed plant communities in the vicinity of Vodny settlement (Komi Republic, Russia). The plant cover recovery started more than 60 years ago, and resulted in overgrowing with common grassland plant species. Three meadow sites were investigated, one with low contamination (on the territory of former radium production plant), one with high contamination (waste storage cell) and a reference sites out of the radiochemical plant zone of influence, but with similar natural conditions. Geo-botanical descriptions revealed 134 vascular plant species from 34 families in the meadow communities studied. The greatest richness was seen for Poaceae, Asteraceae, Rosaceae and Fabaceae families; others had 1-5 species. The highest richness in diversity was seen at reference sites with 95 vascular plant species. 87 species were registered on low contaminated sites and 75 species on high contaminated. Perennial herbs were the dominant life form on all the studied meadow communities. Arboreal species expansion in vegetation was noted at both experimental and reference sites. Shannon index calculations indicated a significant (p<0.05) decrease in species diversity on sample areas of the highly contaminated radioactive waste storage cell. Mean values

  4. Plant Water Stress Affects Interactions Between an Invasive and a Naturalized Aphid Species on Cereal Crops.

    Science.gov (United States)

    Foote, N E; Davis, T S; Crowder, D W; Bosque-Pérez, N A; Eigenbrode, S D

    2017-06-01

    In cereal cropping systems of the Pacific Northwestern United States (PNW), climate change is projected to increase the frequency of drought during summer months, which could increase water stress for crop plants. Yet, it remains uncertain how interactions between herbivore species are affected by drought stress. Here, interactions between two cereal aphids present in PNW cereal systems, Metopolophium festucae (Theobald) subsp. cerealium (a newly invasive species) and Rhopalosiphum padi L. (a naturalized species), were tested relative to wheat water stress. When aphids were confined in leaf cages on wheat, asymmetrical facilitation occurred; per capita fecundity of R. padi was increased by 46% when M. festucae cerealium was also present, compared to when only R. padi was present. Imposed water stress did not influence this interaction. When aphids were confined on whole wheat plants, asymmetrical competition occurred; cocolonization inhibited M. festucae cerealium population growth but did not affect R. padi population growth. Under conditions of plant water stress, however, the inhibitory effect of R. padi on M. festucae cerealium was not observed. We conclude that beneficial effects of cocolonization on R. padi are due to a localized plant response to M. festucae cerealium feeding, and that cocolonization of plants is likely to suppress M. festucae cerealium populations under ample water conditions, but not when plants are water stressed. This suggests that plant responses to water stress alter the outcome of competition between herbivore species, with implications for the structure of pest communities on wheat during periods of drought. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  5. Production of plant cell wall degrading enzymes by monoculture and co-culture of Aspergillus niger and Aspergillus terreus under SSF of banana peels.

    Science.gov (United States)

    Rehman, Shazia; Aslam, Hina; Ahmad, Aqeel; Khan, Shakeel Ahmed; Sohail, Muhammad

    2014-01-01

    Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE), in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase) using a novel substrate, Banana Peels (BP) for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes.

  6. Production of plant cell wall degrading enzymes by monoculture and co-culture of Aspergillus niger and Aspergillus terreus under SSF of banana peels

    Directory of Open Access Journals (Sweden)

    Shazia Rehman

    2014-12-01

    Full Text Available Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE, in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase using a novel substrate, Banana Peels (BP for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes.

  7. Comparing the plant diversity between artificial forest and nature growth forest in a giant panda habitat.

    Science.gov (United States)

    Kang, Dongwei; Wang, Xiaorong; Li, Shuang; Li, Junqing

    2017-06-15

    Artificial restoration is an important way to restore forests, but little is known about its effect on the habitat restoration of the giant panda. In the present study, we investigated the characteristics of artificial forest in the Wanglang Nature Reserve to determine whether through succession it has formed a suitable habitat for the giant panda. We compared artificial forest characteristics with those of natural habitat used by the giant panda. We found that the dominant tree species in artificial forest differed from those in the natural habitat. The artificial forest had lower plant species richness and diversity in the tree and shrub layers than did the latter, and its community structure was characterized by smaller tree and bamboo sizes, and fewer and lower bamboo clumps, but more trees and larger shrub sizes. The typical community collocation of artificial forest was a "Picea asperata + no-bamboo" model, which differs starkly from the giant panda's natural habitat. After several years of restoration, the artificial forest has failed to become a suitable habitat for the giant panda. Therefore, a simple way of planting individual trees cannot restore giant panda habitat; instead, habitat restoration should be based on the habitat requirements of the giant panda.

  8. Zebrafish bioassay-guided natural product discovery: isolation of angiogenesis inhibitors from East African medicinal plants.

    Directory of Open Access Journals (Sweden)

    Alexander D Crawford

    Full Text Available Natural products represent a significant reservoir of unexplored chemical diversity for early-stage drug discovery. The identification of lead compounds of natural origin would benefit from therapeutically relevant bioassays capable of facilitating the isolation of bioactive molecules from multi-constituent extracts. Towards this end, we developed an in vivo bioassay-guided isolation approach for natural product discovery that combines bioactivity screening in zebrafish embryos with rapid fractionation by analytical thin-layer chromatography (TLC and initial structural elucidation by high-resolution electrospray mass spectrometry (HRESIMS. Bioactivity screening of East African medicinal plant extracts using fli-1:EGFP transgenic zebrafish embryos identified Oxygonum sinuatum and Plectranthus barbatus as inhibiting vascular development. Zebrafish bioassay-guided fractionation identified the active components of these plants as emodin, an inhibitor of the protein kinase CK2, and coleon A lactone, a rare abietane diterpenoid with no previously described bioactivity. Both emodin and coleon A lactone inhibited mammalian endothelial cell proliferation, migration, and tube formation in vitro, as well as angiogenesis in the chick chorioallantoic membrane (CAM assay. These results suggest that the combination of zebrafish bioassays with analytical chromatography methods is an effective strategy for the rapid identification of bioactive natural products.

  9. Biological and genetic factors regulating natural competence in a bacterial plant pathogen.

    Science.gov (United States)

    Kung, Stephanie H; Almeida, Rodrigo P P

    2014-01-01

    For naturally competent bacteria, spatially structured growth can provide an environment for enhanced horizontal gene transfer through transformation and recombination. DNA is often present in the extracellular environment, such as in the extracellular matrix of biofilms, and the lysis of a single cell can result in high local DNA concentrations. Xylella fastidiosa is a naturally competent plant pathogen that typically lives in a surface-attached state, yet previous work characterizing the competence of this organism was conducted with planktonic cells in liquid environments. Here, we show that transformation and recombination efficiencies are two to three orders of magnitude higher for cells grown on solid compared with liquid media, with maximum recombination efficiencies of about 10(-3). Cells were highly competent throughout their exponential growth phase, with no significant change in recombination efficiencies until population growth rates began to slow. Mutations in type IV pili, competency-related, and cell-cell signalling genes significantly impacted the ability of X. fastidiosa to acquire and incorporate DNA. Because X. fastidiosa is highly competent when growing in a surface-attached state, as it does within its insect vectors and host plants, recombination of naturally transformed DNA could be a significant route by which horizontal gene transfer occurs in natural environments.

  10. Zebrafish Bioassay-Guided Natural Product Discovery: Isolation of Angiogenesis Inhibitors from East African Medicinal Plants

    Science.gov (United States)

    Crawford, Alexander D.; Liekens, Sandra; Kamuhabwa, Appolinary R.; Maes, Jan; Munck, Sebastian; Busson, Roger; Rozenski, Jef; Esguerra, Camila V.; de Witte, Peter A. M.

    2011-01-01

    Natural products represent a significant reservoir of unexplored chemical diversity for early-stage drug discovery. The identification of lead compounds of natural origin would benefit from therapeutically relevant bioassays capable of facilitating the isolation of bioactive molecules from multi-constituent extracts. Towards this end, we developed an in vivo bioassay-guided isolation approach for natural product discovery that combines bioactivity screening in zebrafish embryos with rapid fractionation by analytical thin-layer chromatography (TLC) and initial structural elucidation by high-resolution electrospray mass spectrometry (HRESIMS). Bioactivity screening of East African medicinal plant extracts using fli-1:EGFP transgenic zebrafish embryos identified Oxygonum sinuatum and Plectranthus barbatus as inhibiting vascular development. Zebrafish bioassay-guided fractionation identified the active components of these plants as emodin, an inhibitor of the protein kinase CK2, and coleon A lactone, a rare abietane diterpenoid with no previously described bioactivity. Both emodin and coleon A lactone inhibited mammalian endothelial cell proliferation, migration, and tube formation in vitro, as well as angiogenesis in the chick chorioallantoic membrane (CAM) assay. These results suggest that the combination of zebrafish bioassays with analytical chromatography methods is an effective strategy for the rapid identification of bioactive natural products. PMID:21379387

  11. Chloroplast ultra structure, photosynthesis and enzyme activities in regenerated plants of Stevia rebaudiana (Bert.) Bertoni as influenced by copper sulphate in the medium.

    Science.gov (United States)

    Jain, Pourvi; Kachhwaha, Sumita; Kothari, S L

    2014-09-01

    Stevia rebaudiana (Bert.) Bertoni is an important medicinal plant used as noncaloric commercial sweetener. Plants regenerated with higher levels of copper sulphate in the medium exhibited enhanced activity of peroxidase and polyphenoloxidase (PPO) enzymes. Transmission electron microscopy (TEM) revealed increase in size and number of electron dense inclusions in the chloroplasts of plants regenerated at optimised level of copper sulphate (0.5 microM) in the medium. There was decrease in chlorogenic acid (CGA) content. Chl-a-fluorescence transient pattern (OJIP) showed that the photosynthesis process was more efficient at 0.5 microM CuSO4 in the medium.

  12. Naturally occurring radioactive material (NORM) from a former phosphoric acid processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Beddow, H. [Geoscience Building, School of Human and Environmental Sciences, Whiteknights, PO Box 227, University of Reading, Reading, Berkshire RG6 6AB (United Kingdom)]. E-mail: h.l.beddow@reading.ac.uk; Black, S. [Geoscience Building, School of Human and Environmental Sciences, Whiteknights, PO Box 227, University of Reading, Reading, Berkshire RG6 6AB (United Kingdom); Read, D. [Enterpris Ltd., Whiteknights, University of Reading, Reading, Berkshire RG6 6AB (United Kingdom); Department of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE (United Kingdom)

    2006-07-01

    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 {sup 238}U and its decay chain products, and significant fractionation along the series occurs. Compared to the feedstock ore, elevated concentrations ({<=}8.8 Bq/g) of {sup 238}U were found to be retained in installations where the process stream was rich in fluorides and phosphates. In addition, enriched levels ({<=}11 Bq/g) of {sup 226}Ra 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.

  13. Relations between urban bird and plant communities and human well-being and connection to nature.

    Science.gov (United States)

    Luck, Gary W; Davidson, Penny; Boxall, Dianne; Smallbone, Lisa

    2011-08-01

    By 2050, 70% of the world's population will live in urban areas. In many cases urbanization reduces the richness and abundance of native species. Living in highly modified environments with fewer opportunities to interact directly with a diversity of native species may adversely affect residents' personal well-being and emotional connection to nature. We assessed the personal well-being, neighborhood well-being (a measure of a person's satisfaction with their neighborhood), and level of connection to nature of over 1000 residents in 36 residential neighborhoods in southeastern Australia. We modeled these response variables as a function of natural features of each neighborhood (e.g., species richness and abundance of birds, density of plants, and amount of vegetation cover) and demographic characteristics of surveyed residents. Vegetation cover had the strongest positive relations with personal well-being, whereas residents' level of connection to nature was weakly related to variation in species richness and abundance of birds and density of plants. Demographic characteristics such as age and level of activity explained the greatest proportion of variance in well-being and connection to nature. Nevertheless, when controlling for variation in demographic characteristics (examples were provided above), neighborhood well-being was positively related to a range of natural features, including species richness and abundance of birds, and vegetation cover. Demographic characteristics and how well-being was quantified strongly influenced our results, and we suggest demography and metrics of well-being must be considered when attempting to determine relations between the urban environment and human well-being. © 2011 Society for Conservation Biology.

  14. Effect of iron stress on Withania somnifera L.: antioxidant enzyme response and nutrient elemental uptake of in vitro grown plants.

    Science.gov (United States)

    Rout, Jyoti Ranjan; Behera, Sadhana; Keshari, Nitin; Ram, Shidharth Sankar; Bhar, Subhajit; Chakraborty, Anindita; Sudarshan, Mathummal; Sahoo, Santi Lata

    2015-03-01

    In the present study the response of antioxidant enzyme activities and the level of expression of their corresponding genes on bioaccumulation of iron (Fe) were investigated. In vitro germinated Withania somnifera L. were grown in Murashige and Skoog's liquid medium with increasing concentrations (0, 25, 50, 100 and 200 µM) of FeSO4 for 7 and 14 days. Root and leaf tissues analyzed for catalase (CAT, EC 1.11.1.6), superoxide dismutase (SOD, EC 1.15.1.1) and guaiacol peroxidase (GPX, EC 1.11.1.7), have shown an increase in content with respect to exposure time. Isoforms of CAT, SOD and GPX were separated using non-denaturing polyacrylamide gel electrophoresis and observed that the isoenzymes were greatly affected by higher concentrations of Fe. Reverse transcriptase polymerase chain reaction analysis performed by taking three pairs of genes of CAT (RsCat, Catalase1, Cat1) and SOD (SodCp, TaSOD1.2, MnSOD) to find out the differential expression of antioxidant genes under Fe excess. RsCat from CAT and MnSOD from SOD have exhibited high levels of gene expression under Fe stress, which was consistent with the changes of the activity assayed in solution after 7 days of treatment. Analysis by proton induced X-ray emission exhibited an increasing uptake of Fe in plants by suppressing and expressing of other nutrient elements. The results of the present study suggest that higher concentration of Fe causes disturbance in nutrient balance and induces oxidative stress in plant.

  15. The effect of natural and planted forest stands on soil fertility in the Hyrcanian region, Iran

    Directory of Open Access Journals (Sweden)

    RAZIYEH RAFEIE JAHED

    2014-10-01

    Full Text Available Rafeie Jahed R, Hosseini SM, Kooch Y. 2014. The effect of natural and planted forest stands on soil fertility in the Hyrcanian region, Iran. Biodiversitas 15: 206-214. In the present work, we studied the effect of natural and planted forest stands on soil fertility in the Hyrcanian region of northern Iran. Natural forest stands (including Acer velutinum Bioss., Zelkova carpinifolia (Pall, Parrotia persica (DC. C.A.Mey, Quercus castaneifolia C.A. Mey., Carpinus betulus L, Mixed planted stand (including Acer velutinum, Ulmus carpinifolia G. Suckow Quercus castaneifolia C.A. Mey, Carpinus betulus L., Tilia begonifolia Scop. Subsp. caucasia (Rupr. Loria; maple (Acer velutinum Bioss plantation, pine (Pinus taeda L. plantation and also clear-cut region (control were considered in this research. Soil samples were collected at two different depths, i.e., 0-15 and 15-30 cm, and characterized with respect to organic carbon (C, total nitrogen (N, available nutrient elements (P, K, Ca and Mg; pH and soil texture. The results showed that the highest amount of total N was found in mixed plantation. The highest amount of available P was detected in maple plantation and pine plantation had the highest available K and organic C than other treatments. The highest and the lowest available Ca and Mg were found in natural forest and control area, respectively. In addition, it was observed that nutrients accumulate in upper layers of the soil. Hardwood stands have been more successful than the conifers stands, so this should be considered in the sustainable management of forests.

  16. The use of plant cell wall-degrading enzymes from newly isolated Penicillium ochrochloron Biourge for viscosity reduction in ethanol production with fresh sweet potato tubers as feedstock.

    Science.gov (United States)

    Huang, Yuhong; Jin, Yanling; Shen, Weiliang; Fang, Yang; Zhang, Guohua; Zhao, Hai

    2014-01-01

    Penicillium ochrochloron Biourge, which was isolated from rotten sweet potato, can produce plant cell wall-degrading enzymes (PCWDEs) with high viscosity reducing capability for ethanol production using fresh sweet potato tubers as feedstock. The enzyme preparation was characterized by a broad enzyme spectrum including 13 kinds of enzymes with the activity to hydrolyze cellulose, hemicellulose, pectin, starch, and protein. The maximum viscosity-reducing capability was observed when the enzyme preparation was obtained after 5 days of fermentation using 20 g/L corncob as a sole carbon source, 4.5 g/L NH4 NO3 as a sole nitrogen source, and an initial medium pH of 6.5. The sweet potato mash treated with the enzyme preparation exhibited much higher fermentation efficiency (92.58%) compared with commercial cellulase (88.06%) and control (83.5%). The enzyme production was then scaled up to 0.5, 5, and 100 L, and the viscosity-reducing rates were found to be 85%, 90%, and 91%, respectively. Thus, P. ochrochloron Biourge displays potential viscosity-reducing capability for ethanol production.

  17. Plant-derived natural medicines for the management of depression: an overview of mechanisms of action.

    Science.gov (United States)

    Farahani, Marzieh Sarbandi; Bahramsoltani, Roodabeh; Farzaei, Mohammad Hosein; Abdollahi, Mohammad; Rahimi, Roja

    2015-01-01

    Depression is a serious widespread psychiatric disorder that affects approximately 17% of people all over the world. Exploring the neurological mechanisms of the antidepressant activity of plant-derived agents could have a crucial role in developing natural drugs for the management of depression. The aim of the present study is to review the neurological mechanisms of action of antidepressant plants and their constituents. For this purpose, electronic databases, including PubMed, Science Direct, Scopus, and Cochrane Library, were searched from 1966 to October 2013. The results showed that several molecular mechanisms could be proposed for the antidepressant activity of medicinal plants and their constituents. Hypericum species could normalize brain serotonin level. Liquiritin and isoliquiritin from Glycyrrhiza uralensis rhizome act via the noradrenergic system. Rosmarinus officinalis and curcumin from Curcuma longa interact with D1 and D2 receptors as well as elevate the brain dopamine level. Sida tiagii and Aloysia gratissima involve γ-aminobutyric acid and N-methyl-D-aspartate receptors, respectively. Fuzi polysaccharide-1 from Aconitum carmichaeli could affect brain-derived neurotrophic factor signaling pathways. Psoralidin from Psoralea corylifolia seed modulate the hypothalamic-pituitary-adrenal axis. The total glycosides of Paeonia lactiflora demonstrate an inhibitory effect on both subtypes of monoamine oxidase. 3,6'-Di-o-sinapoyl-sucrose and tenuifoliside A from Polygala tenuifolia exhibit cytoprotective effects on neuronal cells. Further preclinical and clinical trials evaluating their safety, bioefficacy, and bioavailability are suggested to prove the valuable role of natural drugs in the management of depressive disorders.

  18. Δ9-Tetrahydrocannabinolic acid synthase: The application of a plant secondary metabolite enzyme in biocatalytic chemical synthesis.

    Science.gov (United States)

    Lange, Kerstin; Schmid, Andreas; Julsing, Mattijs K

    2016-09-10

    Δ(9)-Tetrahydrocannabinolic acid synthase (THCAS) from the secondary metabolism of Cannabis sativa L. catalyzes the oxidative formation of an intramolecular CC bond in cannabigerolic acid (CBGA) to synthesize Δ(9)-tetrahydrocannabinolic acid (THCA), which is the direct precursor of Δ(9)-tetrahydrocannabinol (Δ(9)-THC). Aiming on a biotechnological production of cannabinoids, we investigated the potential of the heterologously produced plant oxidase in a cell-free system on preparative scale. THCAS was characterized in an aqueous/organic two-liquid phase setup in order to solubilize the hydrophobic substrate and to allow in situ product removal. Compared to the single phase aqueous setup the specific activity decreased by a factor of approximately 2 pointing to a substrate limitation of CBGA in the two-liquid phase system. However, the specific activity remained stable for at least 3h illustrating the benefit of the two-liquid phase setup. In a repeated-batch setup, THCAS showed only a minor loss of specific activity in the third batch pointing to a high intrinsic stability and high solvent tolerance of the enzyme. Maximal space-time-yields of 0.121gL(-1)h(-1) were reached proving the two-liquid phase concept suitable for biotechnological production of cannabinoids.

  19. Autodisplay of Human Hyaluronidase Hyal-1 on Escherichia coli and Identification of Plant-Derived Enzyme Inhibitors

    Directory of Open Access Journals (Sweden)

    Zoya Orlando

    2015-08-01

    Full Text Available Hyaluronan (HA is the main component of the extracellular matrix (ECM. Depending on its chain size, it is generally accepted to exert diverse effects. High molecular weight HA is anti-angiogenic, immunosuppressive and anti-inflammatory, while lower fragments are angiogenic and inflammatory. Human hyaluronidase Hyal-1 (Hyal-1 is one of the main enzymes in the metabolism of HA. This makes Hyal-1 an interesting target. Not only for functional and mechanistic studies, but also for drug development. In this work, Hyal-1 was expressed on the surface of E. coli, by applying Autodisplay, to overcome formation of inactive “inclusion bodies”. With the cells displaying Hyal-1 an activity assay was performed using “stains-all” dye. Subsequently, the inhibitory effects of four saponins and 14 plant extracts on the activity of surface displayed Hyal-1 were evaluated. The determined IC50 values were 177 µM for glycyrrhizic acid, 108 µM for gypsophila saponin 2, 371 µM for SA1657 and 296 µM for SA1641. Malvae sylvestris flos, Equiseti herba and Ononidis radix extracts showed IC50 values between 1.4 and 1.7 mg/mL. In summary, Autodisplay enabled the expression of functional human target protein Hyal-1 in E. coli and facilitated an accelerated testing of potential inhibitors.

  20. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions.

    Science.gov (United States)

    Lebedev, V G; Faskhiev, V N; Kovalenko, N P; Shestibratov, K A; Miroshnikov, A I

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014-2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity.

  1. PLANT COMMUNITIES WITH ARNICA MONTANA IN NATURAL HABITATS FROM THE CENTRAL REGION OF ROMANIAN EASTERN CARPATHIANS

    Directory of Open Access Journals (Sweden)

    Constantin MARDARI

    2015-12-01

    Full Text Available Arnica montana is a species of European Union interest, whose harvest from the wild and exploitation should be made under certain management measures. In Romania it is a vulnerable species due to excessive collection. It is a species with European areal occuring in pastures, meadows, forest glades, shrubs communities of mountain to the subalpine regions and, isolated, up to the alpine belt. Most of the plant communities with Arnica montana are semi-natural, with a floristic composition in which there are numerous rare or threatened species also supporting the need of their conservation. Our study was focused on a numerical classification (hierarchical, using Flexible ß algorithm and Bray-Curtis dissimilarity based on 48 plots, of the plant communities with Arnica montana from the central region of Romanian Eastern Carpathians and on the investigation of the effect of some environmental variables (Ellenberg indicator values, altitude, heat load index on their floristic composition (100 m2 scale. Vegetation – environment relationship was assessed via detrended correspondence analysis and canonical correspondence analysis with Monte Carlo test. Six plant communities with Arnica montana were identified (communities of Festuca rubra with Agrostis capillaris, Festuca nigrescens, Vaccinium myrtillus, Nardus stricta, Vaccinium gaultherioides and Juniperus sibirica with a floristic composition mainly shaped by altitude, temperature and soil nitrogen content. Details related to location and sites characteristics, diagnostic species, floristic composition, presence of other rare or threatened species and Arnica montana abundance were presented for all these plant communities.

  2. Naturally occurring radioactive materials (NORMs) generated from lignite-fired power plants in Kosovo.

    Science.gov (United States)

    Hasani, F; Shala, F; Xhixha, G; Xhixha, M K; Hodolli, G; Kadiri, S; Bylyku, E; Cfarku, F

    2014-12-01

    The energy production in Kosovo depends primarily on lignite-fired power plants. During coal combustion, huge amounts of fly ash and bottom ash are generated, which may result in enriched natural radionuclides; therefore, these radionuclides need to be investigated to identify the possible processes that may lead to the radiological exposure of workers and the local population. Lignite samples and NORMs of fly ash and bottom ash generated in lignite-fired power plants in Kosovo are analyzed using a gamma-ray spectrometry method for the activity concentration of natural radionuclides. The average activity concentrations of (40)K, (226)Ra and (232)Th in lignite are found to be 36 ± 8 Bq kg(-1), 9 ± 1 Bq kg(-1) and 9 ± 3 Bq kg(-1), respectively. Indications on the occurrence and geochemical behavior of uranium in the lignite matrix are suggested. The activity concentrations of natural radionuclides in fly ash and bottom ash samples are found to be concentrated from 3 to 5 times that of the feeding lignite. The external gamma-ray absorbed dose rate and the activity concentration index are calculated to assess the radiological hazard arising from ash disposal and recycling in the cement industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Naturally occurring arsenic in the groundwater at the Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.

    1990-12-01

    This report describes an investigation concerning the presence of arsenic in concentrations exceeding 0.4 mg/L in the groundwater under the Department of Energy's Kansas City Plant (KCP). The study consisted of four distinct phases: a thorough review of the technical literature, a historical survey of arsenic use at the facility, a laboratory study of existing techniques for determining arsenic speciation, and a field program including water, soil, and sediment sampling. The historical survey and literature review demonstrated that plant activities had not released significant quantities of arsenic to the environment but that similar occurrences of arsenic in alluvial groundwater are widespread in the midwestern United States. Laboratory studies showed that a chromatographic separation technique was necessary to accurately determine arsenic speciation for the KCP groundwater samples. Field studies revealed that naturally occurring reducing conditions prevalent in the subsurface are responsible for dissolving arsenic previously sorbed by iron oxides. Indeed, the data demonstrated that the bulk arsenic concentration of site subsoils and sediments is {approximately}7 mg/kg, whereas the arsenic content of iron oxide subsamples is as high as 84 mg/kg. Literature showed that similar concentrations of arsenic in sediments occur naturally and are capable of producing the levels of arsenic found in groundwater monitoring wells at the KCP. The study concludes, therefore, that the arsenic present in the KCP groundwater is the result of natural phenomena. 44 refs., 8 figs., 14 tabs.

  4. Dye-sensitized solar cells with natural dyes extracted from plant seeds

    Science.gov (United States)

    El-Ghamri, Hatem S.; El-Agez, Taher M.; Taya, Sofyan A.; Abdel-Latif, Monzir S.; Batniji, Amal Y.

    2014-12-01

    The application of natural dyes extracted from plant seeds in the fabrication of dye-sensitized solar cells (DSSCs) has been explored. Ten dyes were extracted from different plant seeds and used as sensitizers for DSSCs. The dyes were characterized using UV-Vis spectrophotometry. DSSCs were prepared using TiO2 and ZnO nanostructured mesoporous films. The highest conversion efficiency of 0.875 % was obtained with an allium cepa (onion) extract-sensitized TiO2 solar cell. The process of TiO2-film sintering was studied and it was found that the sintering procedure significantly affects the response of the cell. The short circuit current of the DSSC was found to be considerably enhanced when the TiO2 semiconducting layer was sintered gradually.

  5. Exploring Cancer Therapeutics with Natural Products from African Medicinal Plants, Part II: Alkaloids, Terpenoids and Flavonoids.

    Science.gov (United States)

    Nwodo, Justina N; Ibezim, Akachukwu; Simoben, Conrad V; Ntie-Kang, Fidele

    2016-01-01

    Cancer stands as second most common cause of disease-related deaths in humans. Resistance of cancer to chemotherapy remains challenging to both scientists and physicians. Medicinal plants are known to contribute significantly to a large population of Africa, which is to a very large extent linked to folkloric claims which is part of their livelihood. In this review paper, the potential of naturally occurring anti-cancer agents from African flora has been explored, with suggested modes of action, where such data is available. Literature search revealed plant-derived compounds from African flora showing anti-cancer and/or cytotoxic activities, which have been tested in vitro and in vivo. This corresponds to 400 compounds (from mildly active to very active) covering various compound classes. However, in this part II, we only discussed the three major compound classes which are: flavonoids, alkaloids and terpenoids.

  6. Lytic Polysaccharide Monooxygenases - Studies of Fungal Secretomes and Enzyme Properties

    DEFF Research Database (Denmark)

    Nekiunaite, Laura

    Efficient degradation of plant biomass by enzymes is an important step towards a more environmentally friendly and sustainable bioeconomy. However, the complexity and recalcitrant nature of the substrates limit enzyme performance on plant biomass and current enzyme cocktails are not efficient...... conversion as they produce a wide diversity of degrading enzymes. In the first part of this PhD thesis, the secretomes of the well-known fungus Aspergillus nidulans grown on cereal and legume starches were analyzed. Secretomics is a powerful tool to unravel secretion patterns of fungi and their response...

  7. Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification.

    Science.gov (United States)

    Longoni, Paolo; Leelavathi, Sadhu; Doria, Enrico; Reddy, Vanga Siva; Cella, Rino

    2015-01-01

    Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2 increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

  8. Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification

    Directory of Open Access Journals (Sweden)

    Paolo Longoni

    2015-01-01

    Full Text Available Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2 increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

  9. Plants Responses to Nutrients Follow the Saturation Kinetic Typical of Enzyme Systems: Biological, Economical and Environmental Implications

    Directory of Open Access Journals (Sweden)

    R. P. Lana

    2008-01-01

    Full Text Available Agricultural efficiency has been associated with high plant productivity. However, it is dependent on fertilizers, which are nonrenewable resources. Crop production response to fertilizers is hyperbolic, following the Michaelis-Menten model and the law of diminishing return. Data of crop production (barley, bean, corn, cotton, soybean and wheat as a function of nitrogen, phosphorus, and potassium fertilization were analyzed by Lineweaver-Burk data transformation (L-B, that allows to calculate the amount of a specific nutrient needed to reach half (ks or other percentages of the theoretical maximum response (kmax and the efficiency of fertilizer use (kg of grain/kg of fertilizer. The efficiency of fertilizer use presented exponential decay by increasing fertilization: 55 to 3; 63 to 5; and 47 to 1 kg of corn/kg of fertilizer, by increasing nitrogen, P2O5 and potassium from 40 to 200; 40 to 200; and 60 to 300 kg ha-1, respectively. The L-B can be an alternative to the linear-plateau and polynomial regression methods of recommendation of plant fertilization, in which the fertilizers recommendation should be based on their efficiency of use, avoiding losses of nutrients, environmental pollution, waste of nonrenewable natural resources, and reducing productive costs.

  10. Snake Venom PLA2s Inhibitors Isolated from Brazilian Plants: Synthetic and Natural Molecules

    Directory of Open Access Journals (Sweden)

    B. M. A. Carvalho

    2013-01-01

    Full Text Available Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2 (PLA2s are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2 inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.

  11. Snake venom PLA2s inhibitors isolated from Brazilian plants: synthetic and natural molecules.

    Science.gov (United States)

    Carvalho, B M A; Santos, J D L; Xavier, B M; Almeida, J R; Resende, L M; Martins, W; Marcussi, S; Marangoni, S; Stábeli, R G; Calderon, L A; Soares, A M; Da Silva, S L; Marchi-Salvador, D P

    2013-01-01

    Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2 (PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2 inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.

  12. The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants.

    Science.gov (United States)

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-12-01

    The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11-12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides as well as (40)K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides

  13. Nutrient presses and pulses differentially impact plants, herbivores, detritivores and their natural enemies.

    Science.gov (United States)

    Murphy, Shannon M; Wimp, Gina M; Lewis, Danny; Denno, Robert F

    2012-01-01

    Anthropogenic nutrient inputs into native ecosystems cause fluctuations in resources that normally limit plant growth, which has important consequences for associated food webs. Such inputs from agricultural and urban habitats into nearby natural systems are increasing globally and can be highly variable, spanning the range from sporadic to continuous. Despite the global increase in anthropogenically-derived nutrient inputs into native ecosystems, the consequences of variation in subsidy duration on native plants and their associated food webs are poorly known. Specifically, while some studies have examined the effects of nutrient subsidies on native ecosystems for a single year (a nutrient pulse), repeated introductions of nutrients across multiple years (a nutrient press) better reflect the persistent nature of anthropogenic nutrient enrichment. We therefore contrasted the effects of a one-year nutrient pulse with a four-year nutrient press on arthropod consumers in two salt marshes. Salt marshes represent an ideal system to address the differential impacts of nutrient pulses and presses on ecosystem and community dynamics because human development and other anthropogenic activities lead to recurrent introductions of nutrients into these natural systems. We found that plant biomass and %N as well as arthropod density fell after the nutrient pulse ended but remained elevated throughout the nutrient press. Notably, higher trophic levels responded more strongly than lower trophic levels to fertilization, and the predator/prey ratio increased each year of the nutrient press, demonstrating that food web responses to anthropogenic nutrient enrichment can take years to fully manifest themselves. Vegetation at the two marshes also exhibited an apparent tradeoff between increasing %N and biomass in response to fertilization. Our research emphasizes the need for long-term, spatially diverse studies of nutrient enrichment in order to understand how variation in the duration

  14. Modelling of plant-soil carbon, nitrogen and phosphorus cycling in semi-natural terrestrial ecosystems

    Science.gov (United States)

    Davies, Jessica; Quinton, John; Rowe, Ed; Tipping, Ed

    2013-04-01

    In recent centuries pools and fluxes of C, N and P in natural and semi-natural UK ecosystems have been transformed by atmospheric pollution leading to: acidification; eutrophication of surface waters; loss of biodiversity; and increased greenhouse gas emissions. In addition, climate change now threatens to perturb these systems further. Understanding in this field is vital in determining the consequences of artificial nutrient enrichment and land use and climate change, and mitigating against their effects. The N14CP model has been recently developed to assess the temporal responses of soil C, N and P pools to nutrient enrichment in semi-natural ecosystems, and explore the connections between these nutrients. It is a dynamic, mechanistic model, driven by: climate; CO2, N (fixation and pollutant deposition), and P (weathering and atmospheric deposition) inputs; and plant cover type. It explicitly links C, N, and P in both plants and soils, using plant element stoichiometry as the primary constraint. Net primary production, and plant/soil element pools, are calculated over time, and output fluxes of dissolved organic and inorganic, and gaseous, forms of C, N, and P produced. Radiocarbon data are used to constrain Soil Organic Matter (SOM) turnover. The SOM is represented as three pools, undergoing first-order decomposition reactions with turn-over rates ranging from 2 to 1000 years. The N14CP modelling methodology is discussed and its calibration and verification using observations from 200 northern European sites presented. Whilst the primary period of interest with respect to nutrient enrichment is from the industrial revolution onwards, plant-soil C, N and P are simulated at these sites for a period spanning from the start of the Holocene (to provide a spin-up period) to the present day. Clearly, during this time span land cover and usage will have changed at these sites, and histories of these changes are used as an input to the model. The influence of these land

  15. Ferns and flowering plants of Klaserie Private Nature Reserve, eastern Transvaal: an annotated checklist

    Directory of Open Access Journals (Sweden)

    N. Zambatis

    1994-12-01

    Full Text Available An annotated checklist of the plant taxa of the Klaserie Private Nature Reserve, eastern Transvaal Lowveld, is presented. Of the 618 infrageneric taxa recorded, six are pteridophytes and the remainder angiosperms. Of these, 161 are monocotyledons and 451 dicotyledons. Five of the latter are currently listed in the Red Data List of the Transvaal, two of which are first records for the Transvaal Lowveld. The vegetation of the reserve shows strong affinities with the Savanna Biome, and to a lesser degree, with the Grassland Biome.

  16. Naturally occurring bioactive Cyclobutane-containing (CBC) alkaloids in fungi, fungal endophytes, and plants.

    Science.gov (United States)

    Dembitsky, Valery M

    2014-10-15

    This article focuses on the occurrence and biological activities of cyclobutane-containing (CBC) alkaloids obtained from fungi, fungal endophytes, and plants. Naturally occurring CBC alkaloids are of particular interest because many of these compounds display important biological activities and possess antitumour, antibacterial, antimicrobial, antifungal, and immunosuppressive properties. Therefore, these compounds are of great interest in the fields of medicine, pharmacology, medicinal chemistry, and the pharmaceutical industry. Fermentation and production of CBC alkaloids by fungi and/or fungal endophytes is also discussed. This review presents the structures and describes the activities of 98 CBC alkaloids.

  17. Ferns and flowering plants of Klaserie Private Nature Reserve, eastern Transvaal: an annotated checklist

    Directory of Open Access Journals (Sweden)

    N. Zambatis

    1994-12-01

    Full Text Available An annotated checklist of the plant taxa of the Klaserie Private Nature Reserve, eastern Transvaal Lowveld, is presented. Of the 618 infrageneric taxa recorded, six are pteridophytes and the remainder angiosperms. Of these, 161 are monocotyledons and 451 dicotyledons. Five of the latter are currently listed in the Red Data List of the Transvaal, two of which are first records for the Transvaal Lowveld. The vegetation of the reserve shows strong affinities with the Savanna Biome, and to a lesser degree, with the Grassland Biome.

  18. Screening for antimicrobial activity of crude drug extracts and pure natural products from Mexican medicinal plants.

    Science.gov (United States)

    Rojas, A; Hernandez, L; Pereda-Miranda, R; Mata, R

    1992-01-01

    Preliminary antimicrobial screening against Candida albicans and selected Gram-positive and Gram-negative bacteria of methanol extracts prepared from eight Mexican medicinal plants, noted for their antiseptic properties, was conducted. The significant activity exhibited for extracts of Ratibida latipalearis, Teloxys graveolens, Dodonaea viscosa, Hyptis albida, H. pectinata, H. Suaveolens and H. verticillata tends to support their traditional use as anti-infective agents. Only the extract of Hintonia latiflora was inactive. The antimicrobial activities of 44 pure natural compounds and two derivatives were determined. Of these, only 23 compounds were effective in inhibiting the growth of the tested organisms (MIC less than or equal to 100 micrograms/ml).

  19. Rational proteomics II: electrostatic nature of cofactor preference in the short-chain oxidoreductase (SCOR) enzyme family.

    Science.gov (United States)

    Pletnev, Vladimir Z; Weeks, Charles M; Duax, William L

    2004-11-01

    The dominant role of long-range electrostatic interatomic interactions in nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NAD/NADP) cofactor recognition has been shown for enzymes of the short-chain oxidoreductase (SCOR) family. An estimation of cofactor preference based only on the contribution of the electrostatic energy term to the total energy of enzyme-cofactor interaction has been tested for approximately 40 known three-dimensional (3D) crystal complexes and approximately 330 SCOR enzymes, with cofactor preference predicted by the presence of Asp or Arg recognition residues at specific 3D positions in the beta2alpha3 loop (Duax et al., Proteins 2003;53:931-943). The results obtained were found to be consistent with approximately 90% reliable cofactor assignments for those subsets. The procedure was then applied to approximately 170 SCOR enzymes with completely uncertain NAD/NADP dependence, due to the lack of Asp and Arg marker residues. The proposed 3D electrostatic approach for cofactor assignment ("3D_DeltaE(el)") has been implemented in an automatic screening procedure, and together with the use of marker residues proposed earlier (Duax et al., Proteins 2003;53:931-943), increases the level of reliable predictions for the putative SCORs from approximately 70% to approximately 90%. It is expected to be applicable for any NAD/NADP-dependent enzyme subset having at least 25-30% sequence identity, with at least one enzyme of known 3D crystal structure.

  20. THE EFFECT OF PLANT SPECIES ON SOME ENZYME ACTIVITIES OF THE SOIL OF A. Ü. Z. F. KENAN EVREN RESEARCH AND EXPERIMENTAL FARM

    OpenAIRE

    Sevinç ARCAK; Ayten KARACA; O. Can TURGAY; HAKTANIR, Koray

    1999-01-01

    The objective of our study was to determine soil urease and ß-Glucosidase enzyme activities in soil samples taken from three different depths (0-5 cm, 5-15 cm and 15-30 cm) and under different type of vegetation (apple, pine, clover, wheat and followed land). Highest activities, both urease and ß- Glucosidase were determined in soil samples representing parcels planted with clover. Enzyme activity showed increase in parcels which have high level of organic matter and total nitrogen. Urease e...

  1. A native plant growth promoting bacterium, Bacillus sp. B55, rescues growth performance of an ethylene-insensitive plant genotype in nature.

    Science.gov (United States)

    Meldau, Dorothea G; Long, Hoang H; Baldwin, Ian T

    2012-01-01

    Many plants have intimate relationships with soil microbes, which improve the plant's growth and fitness through a variety of mechanisms. Bacillus sp. isolates are natural root-associated bacteria, isolated from Nicotiana attenuata plant roots growing in native soils. A particular isolate B55, was found to have dramatic plant growth promotion (PGP) effects on wild type (WT) and transgenic plants impaired in ethylene (ET) perception (35S-etr1), the genotype from which this bacterium was first isolated. B55 not only improves N. attenuata growth under in vitro, glasshouse, and field conditions, but it also "rescues" many of the deleterious phenotypes associated with ET insensitivity. Most notably, B55 dramatically increases the growth and survival of 35S-etr1 plants under field conditions. To our knowledge, this is the first demonstration of a PGP effect in a native plant-microbe association under natural conditions. Our study demonstrates that this facultative mutualistic plant-microbe interaction should be viewed as part of the plant's extended phenotype. Possible modalities of recruitment and mechanisms of PGP are discussed.

  2. Enzyme and biochemical producing fungi

    DEFF Research Database (Denmark)

    Lübeck, Peter Stephensen; Lübeck, Mette; Nilsson, Lena

    2010-01-01

    We are developing a biorefinery concept for biological production of chemicals, drugs, feed and fuels using plant biomass as raw material in well-defined cell-factories. Among the important goals is the discovery of new biocatalysts for production of enzymes, biochemicals and fuels and already our...... screening of a large collection of fungal strains isolated from natural habitats have resulted in identification of strains with high production of hydrolytic enzymes and excretion of organic acids. Our research focuses on creating a fungal platform based on synthetic biology for developing new cell...

  3. Plants vs. cancer: a review on natural phytochemicals in preventing and treating cancers and their druggability.

    Science.gov (United States)

    Wang, Hu; Khor, Tin Oo; Shu, Limin; Su, Zheng-Yuan; Fuentes, Francisco; Lee, Jong-Hun; Kong, Ah-Ng Tony

    2012-12-01

    Cancer remains to be one of the leading causes of death in the United States and around the world. The advent of modern drug-targeted therapies has undeniably improved cancer patients' cares. However, advanced metastasized cancer remains untreatable. Hence, continued searching for a safer and more effective chemoprevention and treatment is clearly needed for the improvement of the efficiency and to lower the treatment cost for cancer care. Cancer chemoprevention with natural phytochemical compounds is an emerging strategy to prevent, impede, delay, or cure cancer. This review summarizes the latest research in cancer chemoprevention and treatment using the bioactive components from natural plants. Relevant molecular mechanisms involved in the pharmacological effects of these phytochemicals are discussed. Pharmaceutical developmental challenges and opportunities in bringing the phytochemicals into the market are also explored. The authors wish to expand this research area not only for their scientific soundness, but also for their potential druggability.

  4. Occupational exposure to natural radioactivity in a zircon sand milling plant

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, Luisa [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: lballest@upvnet.upv.es; Zarza, Isidoro [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: iszarpe@upvnet.upv.es; Ortiz, Josefina [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: jortiz@iqn.upv.es; Serradell, Vicente [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: vserradell@iqn.upv.es

    2008-10-15

    Raw zirconium sand is one of the substances (naturally occurring radioactive material, NORM) which is widely used in the ceramic industry. This sand contains varying concentrations of natural radionuclides: mostly U-238 but also Th-232 and U-235, together with their daughters, and therefore may need to be regulated by Directive 96/29/EURATOM. This paper describes the method used to perform the radiological study on a zircon sand milling plant and presents the results obtained. Internal and external doses were evaluated using radioactivity readings from sand, airborne dust, intermediate materials and end products. The results on total effective dose show the need for this type of industry to be carefully controlled, since values near to 1 mSv were obtained.

  5. Current Status of Natural Products from Plants as Anti-herpes Simplex Virus 1 Agents

    Institute of Scientific and Technical Information of China (English)

    Yang-fei XIANG; Ying PEI; Yi-fei WANG

    2008-01-01

    Nucleoside analogues have been the mainstay of clinical treatment of herpes simplex virus 1 (HSV-1) infections since their development. However, the emergence of drug resistant strains has underlined the urgency of the discovery of novel anti-HSV-1 drugs. Natural products, which provided many novel drug leads, are known to be an important source of anti-HSV-1 agents. Herein, we present an overview of natural products with anti-HSV-1 activities isolated from a variety of plants reported in recent years. Several different compounds, mainly belonging to the three groups of polysaccharides, polyphenols and terpenes, showed antiviral effects against HSV-1, indicating their potential to be promising anti-HSV-1 agents.

  6. Role of Medicinal Plants and Natural Products on Osteoporotic Fracture Healing

    Directory of Open Access Journals (Sweden)

    Mohd Azri Abd Jalil

    2012-01-01

    Full Text Available Popularly known as “the silent disease” since early symptoms are usually absent, osteoporosis causes progressive bone loss, which renders the bones susceptible to fractures. Bone fracture healing is a complex process consisting of four overlapping phases—hematoma formation, inflammation, repair, and remodeling. The traditional use of natural products in bone fractures means that phytochemicals can be developed as potential therapy for reducing fracture healing period. Located closely near the equator, Malaysia has one of the world’s largest rainforests, which are homes to exotic herbs and medicinal plants. Eurycoma longifolia (Tongkat Ali, Labisia pumila (Kacip Fatimah, and Piper sarmentosum (Kaduk are some examples of the popular ethnic herbs, which have been used in the Malay traditional medicine. This paper focuses on the use of natural products for treating fracture as a result of osteoporosis and expediting its healing.

  7. Natural products inhibitors of the angiotensin converting enzyme (ACE: a review between 1980 - 2000 Produtos naturais inibidores da enzima conversora de angiotensina (ECA: uma revisão entre 1980 - 2000

    Directory of Open Access Journals (Sweden)

    José M. Barbosa-Filho

    2006-09-01

    Full Text Available Inhibition of Angiotensin Converting Enzyme (ACE is a modern therapeutic target in the treatment of hypertension. Within the enzyme cascade of the renin-angiotensin system, ACE removes histidyl-leucine from angiotensin I to form the physiologically active octapeptide angiotensin II, one of the most potent known vasoconstrictors. Therefore, a rationale for treating hypertension would be to administer drugs or natural compounds which selectively inhibit ACE. The present work constitutes a review of the literature of plants and chemically defined molecules from natural sources with in vitro anti-hypertensive potential based on the inhibition of ACE. The review refers to 321 plants, the parts utilized, type of extract and whether they are active or not. It includes also the names of 158 compounds isolated from higher plants, marine sponges and algae, fungi and snake venom. Some aspects of recent research with natural products directed to produce anti-hypertensive drugs are discussed. In this review, 148 references were cited.A inibição da Enzima Conversora da Angiotensina (ECA é um alvo terapêutico moderno e eficaz no tratamento da hipertensão arterial. Na cascata enzimática que envolve o sistema renina-angiotensina, a ECA promove a remoção dos aminoácidos histidil-leucina da angiotensina I para formar o octapeptídio angiotensina II, a qual é fisiologicamente ativa em diversos sistemas, e considerado como um dos mais potentes vasoconstrictores endógenos conhecido. Portanto, uma racionalidade no tratamento da hipertensão seria administrar drogas ou compostos de origem natural que inibam seletivamente a ECA. O presente estudo constitui uma revisão da literatura sobre plantas e moléculas de origem natural com potencial anti-hipertensivo, baseado na inibição in vitro da ECA. A revisão referencia 321 plantas, partes usadas, tipo de extrato e se é ativo ou não. Inclui ainda o nome de 158 compostos isolados de plantas superiores

  8. When there is no escape: the effects of natural enemies on native, invasive, and noninvasive plants.

    Science.gov (United States)

    Parker, Ingrid M; Gilbert, Gregory S

    2007-05-01

    An important question in the study of biological invasions is the degree to which successful invasion can be explained by release from control by natural enemies. Natural enemies dominate explanations of two alternate phenomena: that most introduced plants fail to establish viable populations (biotic resistance hypothesis) and that some introduced plants become noxious invaders (natural enemies hypothesis). We used a suite of 18 phylogenetically related native and nonnative clovers (Trifolium and Medicago) and the foliar pathogens and invertebrate herbivores that attack them to answer two questions. Do native species suffer greater attack by natural enemies relative to introduced species at the same site? Are some introduced species excluded from native plant communities because they are susceptible to local natural enemies? We address these questions using three lines of evidence: (1) the frequency of attack and composition of fungal pathogens and herbivores for each clover species in four years of common garden experiments, as well as susceptibility to inoculation with a common pathogen; (2) the degree of leaf damage suffered by each species in common garden experiments; and (3) fitness effects estimated using correlative approaches and pathogen removal experiments. Introduced species showed no evidence of escape from pathogens, being equivalent to native species as a group in terms of infection levels, susceptibility, disease prevalence, disease severity (with more severe damage on introduced species in one year), the influence of disease on mortality, and the effect of fungicide treatment on mortality and biomass. In contrast, invertebrate herbivores caused more damage on native species in two years, although the influence of herbivore attack on mortality did not differ between native and introduced species. Within introduced species, the predictions of the biotic resistance hypothesis were not supported: the most invasive species showed greater infection

  9. Developmental plasticity and reduced susceptibility to natural enemies following host plant defoliation in a specialized herbivore.

    Science.gov (United States)

    Hood, Glen R; Ott, James R

    2010-03-01

    Host-specific phytophagous insects that are short lived and reliant on ephemeral plant tissues provide an excellent system in which to investigate the consequences of disruption in the timing of resource availability on consumer populations and their subsequent interactions with higher tropic levels. The specialist herbivore, Belonocnema treatae (Hymenoptera: Cynipidae) induces galls on only newly flushed leaves of live oak, Quercus fusiformis. In central Texas (USA) episodic defoliation of the host creates variation in the timing of resource availability and results in heterogeneous populations of B. treatae that initiate development at different times. We manipulated the timing of leaf flush in live oak via artificial defoliation to test the hypothesis that a 6- to 8-week delay in the availability of resources alters the timing of this gall former's life cycle events, performance and survivorship on its host, and susceptibility to natural enemies. B. treatae exhibits plasticity in development time, as the interval from egg to emergence was significantly reduced when gallers oviposited into the delayed leaf flush. As a consequence, the phenologies of gall maturation and adult emergence remain synchronized in spite of variation in the timing of resource availability. Per capita gall production and gall-former performance are not significantly affected by the timing of resource availability. The timing of resource availability and natural enemies interact, however, to produce strong effects on survivorship: when exposed to natural enemies, B. treatae developing in galls initiated by delayed oviposition exhibited an order-of-magnitude increase in survivorship. Developmental plasticity allows this gall former to circumvent disruptions in resource availability, maintain synchrony of life cycle events, and results in reduced vulnerability to natural enemies following defoliation of the host plant.

  10. Relationship of soybean aphid (Hemiptera: Aphididae) to soybean plant nutrients, landscape structure, and natural enemies.

    Science.gov (United States)

    Noma, Takuji; Gratton, Claudio; Colunga-Garcia, Manuel; Brewer, Michael J; Mueller, Emily E; Wyckhuys, Kris A G; Heimpel, George E; O'Neal, Matthew E

    2010-02-01

    In the north central United States, populations of the exotic soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are highly variable across space, complicating effective aphid management. In this study we examined relationships of plant nutrients, landscape structure, and natural enemies with soybean aphid abundance across Iowa, Michigan, Minnesota, and Wisconsin, representing the range of conditions where soybean aphid outbreaks have occurred since its introduction. We sampled soybean aphid and its natural enemies, quantified vegetation land cover and measured soybean nutrients (potassium [K] and nitrogen [N]) in 26 soybean sites in 2005 and 2006. Multiple regression models found that aphid abundance was negatively associated with leaf K content in 2005, whereas it was negatively associated with habitat diversity (Simpson's index) and positively associated with leaf N content in 2006. These variables accounted for 25 and 27% of aphid variability in 2005 and 2006, respectively, suggesting that other sources of variability are also important. In addition, K content of soybean plants decreased with increasing prevalence of corn-soybean cropland in 2005, suggesting that landscapes that have a high intensification of agriculture (as indexed by increasing corn and soybean) are more likely to have higher aphid numbers. Soybean aphid natural enemies, 26 species of predators and parasitoids, was positively related to aphid abundance; however, enemy-to-aphid abundance ratios were inversely related to aphid density, suggesting that soybean aphids are able to escape control by resident natural enemies. Overall, soybean aphid abundance was most associated with soybean leaf chemistry and landscape heterogeneity. Agronomic options that can ameliorate K deficiency and maintaining heterogeneity in the landscape may reduce aphid risk.

  11. Quality-related enzymes in plant-based products: effects of novel food-processing technologies part 3: ultrasonic processing.

    Science.gov (United States)

    Terefe, Netsanet Shiferaw; Buckow, Roman; Versteeg, Cornelis

    2015-01-01

    High-power ultrasound is a versatile technology which can potentially be used in many food processing applications including food preservation. This is part 2 of a series of review articles dealing with the effectiveness of nonthermal food processing technologies in food preservation focusing on their effect on enzymes. Typically, ultrasound treatment alone does not efficiently cause microbial or enzyme inactivation sufficient for food preservation. However, combined with mild heat with or without elevated pressure (P ≤ 500 kPa), ultrasound can effectively inactivate enzymes and microorganisms. Synergistic effects between ultrasound and mild heat have been reported for the inactivation of both enzymes and microorganisms. The application of ultrasound has been shown to enhance the rate of inactivation of quality degrading enzymes including pectin methylesterase (PME), polygalacturonase (PG), peroxidase (POD), polyphenol oxidase (PPO), and lipoxygenase (LOX) at mild temperature by up to 400 times. Moreover, ultrasound enables the inactivation of relatively heat-resistant enzymes such as tomato PG1 and thermostable orange PME at mild temperature conditions. The extent to which ultrasound enhances the inactivation rate depends on the type of enzyme, the medium in which the enzyme is suspended, and the processing condition including frequency, ultrasonic intensity, temperature, and pressure. The physical and chemical effects of cavitation are considered to be responsible for the ultrasound-induced inactivation of enzymes, although the dominant mechanism depends on the structure of the enzyme.

  12. Quality-related enzymes in plant-based products: effects of novel food processing technologies part 2: pulsed electric field processing.

    Science.gov (United States)

    Terefe, Netsanet Shiferaw; Buckow, Roman; Versteeg, Cornelis

    2015-01-01

    Pulsed electric field (PEF) processing is an effective technique for the preservation of pumpable food products as it inactivates vegetative microbial cells at ambient to moderate temperature without significantly affecting the nutritional and sensorial quality of the product. However, conflicting views are expressed about the effect of PEF on enzymes. In this review, which is part 2 of a series of reviews dealing with the effectiveness of novel food preservation technologies for controlling enzymes, the scientific literature over the last decade on the effect of PEF on plant enzymes is critically reviewed to shed more light on the issue. The existing evidence indicates that PEF can result in substantial inactivation of most enzymes, although a much more intense process is required compared to microbial inactivation. Depending on the processing condition and the origin of the enzyme, up to 97% inactivation of pectin methylesterase, polyphenol oxidase, and peroxidase as well as no inactivation have been reported following PEF treatment. Both electrochemical effects and Ohmic heating appear to contribute to the observed inactivation, although the relative contribution depends on a number of factors including the origin of the enzyme, the design of the PEF treatment chamber, the processing condition, and the composition of the medium.

  13. Robust Control of PEP Formation Rate in the Carbon Fixation Pathway of C4 Plants by a Bi-functional Enzyme

    Directory of Open Access Journals (Sweden)

    Hart Yuval

    2011-10-01

    Full Text Available Abstract Background C4 plants such as corn and sugarcane assimilate atmospheric CO2 into biomass by means of the C4 carbon fixation pathway. We asked how PEP formation rate, a key step in the carbon fixation pathway, might work at a precise rate, regulated by light, despite fluctuations in substrate and enzyme levels constituting and regulating this process. Results We present a putative mechanism for robustness in C4 carbon fixation, involving a key enzyme in the pathway, pyruvate orthophosphate dikinase (PPDK, which is regulated by a bifunctional enzyme, Regulatory Protein (RP. The robust mechanism is based on avidity of the bifunctional enzyme RP to its multimeric substrate PPDK, and on a product-inhibition feedback loop that couples the system output to the activity of the bifunctional regulator. The model provides an explanation for several unusual biochemical characteristics of the system and predicts that the system's output, phosphoenolpyruvate (PEP formation rate, is insensitive to fluctuations in enzyme levels (PPDK and RP, substrate levels (ATP and pyruvate and the catalytic rate of PPDK, while remaining sensitive to the system's input (light levels. Conclusions The presented PPDK mechanism is a new way to achieve robustness using product inhibition as a feedback loop on a bifunctional regulatory enzyme. This mechanism exhibits robustness to protein and metabolite levels as well as to catalytic rate changes. At the same time, the output of the system remains tuned to input levels.

  14. Sustainable management and supply of natural and recycled aggregates in a medium-size integrated plant.

    Science.gov (United States)

    Faleschini, Flora; Zanini, Mariano Angelo; Pellegrino, Carlo; Pasinato, Stefano

    2016-03-01

    The consumption of natural aggregates in civil engineering applications can cause severe environmental impacts on a regional scale, depleting the stock of bulk resources within a territory. Several methods can improve the environmental sustainability of the whole aggregates' supply process, including natural and recycled aggregates' productive chains, for instance promoting the use of recycled aggregates (RA). However, when quarrying and recycling activities are considered as stand-alone processes, also the RA supply chain may not be as sustainable as expected, due to the high environmental loads associated to transportation, if high distances from the production to the use sites are involved. This work gives some insights on the environmental impact assessment of the aggregates' industry in the Italian context, through a comparative assessment of the environmental loads of natural and recycled aggregates' productive chains. An integrated plant for the extraction of virgin aggregates and recycling of construction and demolition waste (C&DW) was analyzed as significant case study, with the aim to identify the influence of sustainable solutions on the overall emissions of the facility. A Life Cycle Assessment (LCA) approach was used, using site-specific data and paying particular attention on transportation-related impacts, land use, avoided landfill and non-renewable resources preservation. From this work it was possible to evaluate the influence of transportation and PV energy use on the overall environmental emissions of natural and recycled aggregates' productive chains.

  15. A comparative study on plant diversity in alder (Alnus subcordata stands of natural and plantation areas

    Directory of Open Access Journals (Sweden)

    SEYED ALIAKBAR REZAEI TALESHI

    2014-11-01

    Full Text Available Diversity index is the useful criteria for evaluating sustainability of forest ecosystems. Current study carried out in Alder (Alnus subcordata C.A. Meyer stands that located in north forests of Iran. The aim of the study is express the plant diversity indices and positive role of the trees both natural and plantation forms. Data of Alder trees and associated species were recorded in sample plots which lay down in study area randomly. The abundance, density, percentage of frequency of each species was calculated by standard methods. The results of analysis revealed that, 47 species (21 trees and shrubs species and 26 herbaceous species were abundant in 80 sample plots both in natural and plantations Alder stands. Whilst the results showed that the number of species in natural area (44 species was more than plantation stands (37 species. Comparison of species distribution in different physiographical situation showed that some species such as Alnus subcordata, Parrotia persica, Rubus hyrcanus and Prunus sp. recorded in spread rang of physiographic variables as elevation, slopes and aspects. The biodiversity criteria as Shannon H’ and Simpsons D and 1/D indexes showed that they were more in natural stands than plantation areas.

  16. Effects of Occupational Exposure with Mixture of Aromatic Organic Solvents on Liver Enzymes in Workers of an Automobile Plant

    Directory of Open Access Journals (Sweden)

    MS Attarchi

    2009-10-01

    Full Text Available Introduction & Objective: Organic solvents have a broad range of application in industry. Hepatotoxicity of different organic halogenated solvents like carbon tetrachloride has been verified in numerous studies however, studies investigating the association between the occupational exposure with aromatic organic solvents like benzene, toluene & xylene and hepatic toxicity are limited. The goal of this study was to review the long term effects of exposure with mixture of aromatic organic solvents, in higher amounts of permissible level, on hepatic system. Materials & methods: This is a cross sectional study which was conducted in an automobile plant. Workers employed in the painting saloon were considered as cases and workers in assembly as controls. A questionnaire, containing demographic data like age and years of employment, was completed for each of 349 workers. After considering exclusion criteria, liver enzyme level (AST, ALT & ALP of 163 case workers was compared with 186 controls. Concentration of mixture of organic solvents in painting saloon was twice and a half as much of the permissible level. The collected data was analyzed by the SPSS software, using T score, K2 and Linear Regression. Results: The Mean level of ALP in case group was significantly higher than the control group (P<0.001. For AST and ALT the mean was higher in the case group but this difference was not statistically significant. Increase in ALP level had a significant association with BMI (P<0.001 and smoking (P=0.007 yet, no significant relation was seen with age and years of employment. Conclusion: Our study suggested that exposure with mixture of aromatic organic solvents, in higher amounts of permissible level, can cause mild functional liver damage (cholestatic type. So, it is recommended to use liver function tests, especially ALP, for screening of workers exposed to mixture of aromatic organic solvents, for preliminary detection of hepatic dysfunction.

  17. The effect of the Falcon 460 EC fungicide on soil microbial communities, enzyme activities and plant growth.

    Science.gov (United States)

    Baćmaga, Małgorzata; Wyszkowska, Jadwiga; Kucharski, Jan

    2016-10-01

    Fungicides are considered to be effective crop protection chemicals in modern agriculture. However, they can also exert toxic effects on non-target organisms, including soil-dwelling microbes. Therefore, the environmental fate of fungicides has to be closely monitored. The aim of this study was to evaluate the influence of the Falcon 460 EC fungicide on microbial diversity, enzyme activity and resistance, and plant growth. Samples of sandy loam with pHKCl 7.0 were collected for laboratory analyses on experimental days 30, 60 and 90. Falcon 460 EC was applied to soil in the following doses: control (soil without the fungicide), dose recommended by the manufacturer, 30-fold higher than the recommended dose, 150-fold higher than the recommended dose and 300-fold higher than the recommended dose. The observed differences in the values of the colony development index and the eco-physiological index indicate that the mixture of spiroxamine, tebuconazole and triadimenol modified the biological diversity of the analyzed groups of soil microorganisms. Bacteria of the genus Bacillus and fungi of the genera Penicillium and Rhizopus were isolated from fungicide-contaminated soil. The tested fungicide inhibited the activity of dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase. The greatest changes were induced by the highest fungicide dose 300-fold higher than the recommended dose. Dehydrogenases were most resistant to soil contamination. The Phytotoxkit test revealed that the analyzed fungicide inhibits seed germination capacity and root elongation. The results of this study indicate that excessive doses of the Falcon 460 EC fungicide 30-fold higher than the recommended dose to 300-fold higher than the recommended dose) can induce changes in the biological activity of soil. The analyzed microbiological and biochemical parameters are reliable indicators of the fungicide's toxic effects on soil quality.

  18. Mechanisms of nitric oxide crosstalk with reactive oxygen species scavenging enzymes during abiotic stress tolerance in plants.

    Science.gov (United States)

    Arora, Dhara; Jain, Prachi; Singh, Neha; Kaur, Harmeet; Bhatla, Satish C

    2016-01-01

    Nitric oxide (NO) acts in a concentration and redox-dependent manner to counteract oxidative stress either by directly acting as an antioxidant through scavenging reactive oxygen species (ROS), such as superoxide anions (O(2)(-)*), to form peroxynitrite (ONOO(-)) or by acting as a signaling molecule, thereby altering gene expression. NO can interact with different metal centres in proteins, such as heme-iron, zinc-sulfur clusters, iron-sulfur clusters, and copper, resulting in the formation of a stable metal-nitrosyl complex or production of varied biochemical signals, which ultimately leads to modification of protein structure/function. The thiols (ferrous iron-thiol complex and nitrosothiols) are also involved in the metabolism and mobilization of NO. Thiols bind to NO and transport it to the site of action whereas nitrosothiols release NO after intercellular diffusion and uptake into the target cells. S-nitrosoglutathione (GSNO) also has the ability to transnitrosylate proteins. It is an NO˙ reservoir and a long-distance signaling molecule. Tyrosine nitration of proteins has been suggested as a biomarker of nitrosative stress as it can lead to either activation or inhibition of target proteins. The exact molecular mechanism(s) by which exogenous and endogenously generated NO (or reactive nitrogen species) modulate the induction of various genes affecting redox homeostasis, are being extensively investigated currently by various research groups. Present review provides an in-depth analysis of the mechanisms by which NO interacts with and modulates the activity of various ROS scavenging enzymes, particularly accompanying ROS generation in plants in response to varied abiotic stress.

  19. Natural transformation in plant breeding - a biotechnological platform for quality improvement of ornamental, agricultural and medicinal plants

    DEFF Research Database (Denmark)

    Lütken, Henrik Vlk; Hegelund, Josefine Nymark; Himmelboe, Martin;

    2015-01-01

    Compactness is a desirable trait in ornamental plant breeding because it is preferred by producers, distributors and consumers. Presently, in ornamental plant production growth of many potted plants is regulated by application of chemical growth retardants, several of which are harmful to both......, decreased plant height, short internodes, reduced apical dominance and changes in flower characteristics. Several of these traits improve ornamental plant quality and may also benefit characteristics useful in agricultural field crops. In addition, a number of regenerated plants derived from hairy roots...

  20. INDUCTION OF ENZYME COCKTAILS BY LOW COST CARBON SOURCES FOR PRODUCTION OF MONOSACCHARIDE-RICH SYRUPS FROM PLANT MATERIALS

    Directory of Open Access Journals (Sweden)

    Caroline T. Gilleran

    2010-05-01

    Full Text Available The production of cellulases, hemicellulases, and starch-degrading enzymes by the thermophilic aerobic fungus Talaromyces emersonii under liquid state culture on various food wastes was investigated. A comprehensive enzyme screening was conducted, which resulted in the identification of spent tea leaves as a potential substrate for hydrolytic enzyme production. The potent, polysaccharide-degrading enzyme-rich cocktail produced when tea leaves were utilised as sole carbon source was analysed at a protein and mRNA level and shown to exhibit high level production of key cellulose and hemicellulose degrading enzymes. As presented in this paper, the crude enzyme preparation produced after 120 h growth of Talaromyces emersonii on used tea leaves is capable of hydrolysing other lignocellulosic materials into their component monosaccharides, generating high value sugar syrups with a host of industrial applications including conversion to fuels and chemicals.

  1. Measures against the adverse impact of natural wind on air-cooled condensers in power plant

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant.It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers.Based on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed.The physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD simulation.The back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled condensers.The results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind.

  2. Performance Evaluation of Refrigeration Units in Natural Gas Liquid Extraction Plant

    Directory of Open Access Journals (Sweden)

    Awajiogak Anthony Ujile

    2014-01-01

    Full Text Available This paper has applied thermodynamics principles to evaluate the reliability of 390 m3/hr natural gas processing plant. The thermodynamics equations were utilized in the evaluation, characterization, and numerical simulation of key process parameters in natural gas liquid extraction plant. The results obtained show the comparison of the coefficient of performance, compression ratio, isentropic work, actual work, electrical power requirements, cooling water consumption in intercoolers, compressor power output, compressor capacity, and isentropic, volumetric, and mechanical efficiency of the two-stage refrigeration unit with a flash gas economizer and these were compared with the designed specifications. The second law of thermodynamics was applied in analyzing the refrigeration unit and the result shows that exergetic losses or lost work due to irreversibility falls within operating limit that is less than 1.0%. Similarly, the performance of expansion turbine (expander parameters was monitored and the results indicate a considerable decrease in turbine efficiencies as the inlet gas pressure increases resulting in an increased power output of the turbine leading to a higher liquefaction rate.

  3. Comparison of Iran Power Plants Air Pollutants Before and After Shifting to Natural Gas

    Directory of Open Access Journals (Sweden)

    M Ghiasseddin

    2004-07-01

    Full Text Available In a three years period, 24 fossil fueled thermal power plants located in different parts of the country were extensively examined for discharge of pollutants into the environment and their potential effects on surrounding. During this investigation emission to air, discharge to receiving waters and land as well as electromagnetic fields were measured using relevant standard methods. This paper will focus on air pollution emissions and recent reinvestigation that was done after shifting the fuel from residual oil to natural gas. In our first studies that most of the plants were consuming residual oil, high level of SO2 emission in some areas was the main cause of losses to vegetations and fruit gardens. It was concluded that a serious problem threats the environment and health of people living near these areas. Based on the results some mitigation plans were recommended to the authorities, and after some times they started to shift to natural gas consumption. Our recent investigation that was after this action, showed a good improvement of air pollution reduction. This was almost 100% for SO2 and from 32 to 73% for NOx.

  4. Increasing the capacity of the NEAG natural gas processing plants; Kapazitaetssteigerung der Erdgasaufbereitungsanlagen der NEAG

    Energy Technology Data Exchange (ETDEWEB)

    Rest, W.; Weiss, A. [Mobil Erdgas-Erdoel GmbH, Celle (Germany)

    1998-12-31

    The fact that new deposits of sour natural gas were found in the concessions at Scholen/Wesergebirgsvorland and that a sour gas pipeline was built from the BEB-operated field in South-Oldenburg increased the sour gas volume handled by the North German Natural Gas Processing Company (NEAG) so much, that capacities had to be stepped up. This paper describes the measures taken to increase capacities. Various interesting process engineering methods employed to remove bottlenecks in the parts of the plant are described in detail. These refer to the modification of the baffle plates in the high-pressure absorber of the Purisolwashers NEAG I, as well as in the expansion tank and the purified gas waher of the NEAG III washing plant as well as comprehensive modifications of the MODOP-flue gas scrubber NEAG III (orig.) [Deutsch] Neue Sauergasfunde in den Konzessionen Scholen/Wiehengebirgsvorland sowie der Bau der Sauergasverbindungsleitung aus dem von BEB operierten Feldesbereich Sued-Oldenburg haben die der Norddeutschen Erdgas-Aufbereitungsgesellschaft (NEAG) in Voigtei angebotenen Sauergasmengen soweit erhoeht, dass eine Kapazitaetserhoehung notwendig wurde. Im Rahmen des Vortrages werden die Massnahmen zur Kapazitaetssteigerung vorgestellt. Einige verfahrenstechnisch besonders interessante Loesungen zur Beseitigung von Engpaessen in Anlagenteilen werden detailliert beschrieben. Es handelt sich hierbei um die Modifikation der Einbauten im Hochdruckabsorber der Purisolwaesche NEAG I, im Entspannungsbehaelter und Reingaswaescher der Waesche NEAG III sowie umfangreiche Aenderungen im Bereich der MODOP-Abgasreinigungsanlage NEAG III. (orig.)

  5. Characteristic of Tuber spp. localities in natural stands with emphasis on plant species composition

    Directory of Open Access Journals (Sweden)

    Dorota Hilszczanska

    2014-12-01

    Full Text Available Fungi belonging to the genus Tuber establish ectomycorrhizal symbioses with shrubs, trees and some herbaceous plants. Some Tuber species, for example, T. melanosporum, T. magnatum, T. aestivum are economically important because they produce edible fruiting bodies with a distinctive taste and flavor. Our concept of truffle ecophysiology is dominated by the symbiosis with deciduous hosts, such as: Quercus spp., Fagus sylvatica, Castanea sativa, Corylus spp., Carpinus betulus, Ostrya carpinifolia, Betula verrucosa, and Tilia spp., whereas the real range of hosts in nature seems to be much wider. Moreover, interactions between Tuber mycelium and plant community could be more complex than just forming the ectomycorrhizal symbiosis. Here we show our inventory of plants and soils at six truffle’ sites in the southern part of Poland (Nida Basin and Przedbórz Upland. The aim of this study was to widen our understanding of ecological factors affecting Tuber spp., in the context of pioneering stage of research on truffles in Poland. We hope our findings will have a practical application and will help to choose suitable soils for truffle orchards.

  6. Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

    2010-07-01

    Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

  7. NATURE OF WAVE PROCESSES AND THEIR INTERACTION WITH Tidal power PLANTS

    Directory of Open Access Journals (Sweden)

    Alekseeva Ol'ga Aleksandrovna

    2012-07-01

    Full Text Available The author examines the nature of wave processes and their impact on the operation of tidal power plants. The article also has an overview of both operating and prospective tidal power plants in Russia and worldwide. Patterns of tidal fluctuations and the intensity of their driving forces are also considered in the article. The author discloses the origin of tides in terms of elementary physics and hydraulics. The author covers various aspects of formation of different types of inequality of tides caused by alterations in the mutual positions of the Sun and the Moon in relation to the Earth, variable declination of tide-generating luminaries (the Sun and the Moon in relation to the plane of the Earth equator, and variable distance between the luminaries and the Earth. The author analyzes wave-related phenomena, including refraction, diffraction and interference, their origin and influence onto the properties of waves. The author also covers the origin of advancing and standing waves, or waves of mixed origin, and the impact of the wind onto the characteristics of wave fluctuations. The author provides suggestions regarding potential methods of their control that can affect the essential concept of construction of tidal power plants.

  8. Great gas plants : these five natural gas processing facilities demonstrate decades of top-flight technology

    Energy Technology Data Exchange (ETDEWEB)

    Byfield, M.

    2010-07-15

    The natural gas purification and pipeline sector is a major economic driver in Canada. Gas processing facilities are growing in number, and several large gas projects are being planned for future construction in the western provinces. This article outlined 5 gas plants in order to illustrate the sector's history and breadth in Canada. The Shell Jumping Pound gas complex was constructed in 1951 after a sulfur-rich gas discovery near Calgary in 1944. The Empress Straddle plant was built in 1971 in southeastern Alberta and is one of the largest single industrial consumers of electrical power in the province. The Fort Nelson gas processing plant is North America's largest sour gas processing facility. The Shell Caroline complex was built 1993. The Sable offshore energy project is located on the coast of Nova Scotia to handle gas produced from the Thebaud wells. A consortium is now considering the development of new gas fields in the Sable area. 5 figs.

  9. Presence of Naturally Occurring Radioactive Materials in sludge samples from several Spanish water treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, M.; Penalver, A.; Aguilar, C. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Consorci d' Aigues de Tarragona (CAT), Ctra. Nacional 340 Km. 1094, Ap. correus n.7, 43895 L' Ampolla, Tarragona (Spain); Borrull, F., E-mail: francesc.borrull@urv.cat [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Consorci d' Aigues de Tarragona (CAT), Ctra. Nacional 340 Km. 1094, Ap. correus n.7, 43895 L' Ampolla, Tarragona (Spain)

    2010-09-15

    Sludge samples from eleven potable water treatment plants (PWTP), three waste water treatment plants (WWTP) and an industrial water treatment plant (IWTP), located in different areas of Spain, mainly in Catalonia, were analyzed for their radiological content in order to determine whether they could be considered as industries affected by naturally occurring radioactive material (NORM). In general, samples from the PWTPs showed higher activity values for the alpha and gamma emitting isotopes than the WWTPs and the IWTP. For example, samples from the area located in the north of Catalonia show values of {sup 234}U, {sup 235}U and {sup 238}U in the range of 84.4-792.1 Bq/kg, 3.3-26.8 Bq/kg and 63.8-585.9 Bq/kg, respectively. In general, for PWTP, the values obtained for the gamma emitter and alpha emitter isotopes showed that both the geology and the industrial activities correlate with the values measured. The magnitude of these results demonstrates the need to measure the radionuclide content of these samples before reaching a decision about their final disposal.

  10. Distribution, host plants and natural enemies of sugar beet root aphid (Pemphigus fuscicornis In Slovakia

    Directory of Open Access Journals (Sweden)

    Tóth Peter

    2006-01-01

    Full Text Available During 2003-2004, field surveys were realized to observe the distribution of sugar beet aphid, Pemphigus fuscicornis (K o c h (Sternorrhyncha Pemphigidae in southwestern Slovakia. The research was carried out at 60 different localities with altitudes 112-220 m a. s. l. Sugar beet root aphid was recorded at 30 localities. The aphid was recorded in Slovakia for the first time, but its occurrence was predicted and symptoms and harmfulness overlooked by now. The presence of P. fuscicornis was investigated on roots of various plants from Chenopodiaceae. The most important host plants were various species of lambsquarters (above all Chenopodium album. Furthermore sugar beet (Beta vulgaris provar. altissima, red beet (B. vulgaris provar. conditiva and oraches (Atriplex spp act as host plants. Infestation of sugar beet by P. fuscicornis never exceeded 5% at single locality in Slovakia. Dry and warm weather create presumptions for strong harmfulness. In Slovakia, Chenopodium album is a very important indicator of sugar beet aphid presence allowing evaluation of control requirements. During the study, the larvae of Thaumatomyia glabra (Diptera: Chloropidae were detected as important natural enemies of sugar beet aphid. The species occurred at each location evaluated.

  11. Determination of natural colorants in plant extracts by high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    RENETA GEVRENOVA

    2010-07-01

    Full Text Available The determination of the colouring compounds apigenin (1, lawsone (2, juglone (3 and indigotin (4 in plant extracts using HPLC–UV/Vis methods is reported. The methods were applied to the analysis of 1–4 in ethanolic and propylene glycolic extracts originating, respectively, from chamomile (Chamomilla recutita [L] Rauschert, Asteraceae, henna (Lawsonia inermis L., Lythraceae, walnut (Juglans regia L., Juglandaceae and natural indigo (Indigofera sp., Fabaceae. In the case of the indigo extracts, an optimized acid hydrolysis was applied. HPLC separations were performed on a Hypersil ODS RP18 column using linear gradient elution programs. The detection limits for 1–4 were 0.11, 0.6, 0.10, 0.089 μg mL-1, respectively. The procedure did not involve any sample “clean-up” methods. The amounts of the colouring compounds ranged from 0.006 (3 to 0.13 mg mL-1 (4 in the ethanolic extracts and from 0.22 (2 to 1.44 mg mL-1 (4 in propylene glycolic extracts. The proposed HPLC methods are advantageous in terms of sample preparation and the selective separation of the compounds. The plant dye extracts are commonly used in hair colouring formulations. The results indicate that the methods developed may serve for the quantitative control of dying plants and cosmetic products.

  12. Structural walkdown procedure for natural phenomena engineering analyses at the Oak Ridge Y-12 Plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-06-01

    This walkdown plan outlines the process to be followed and the pertinent structural information to be collected for the assessment of the adequacy of existing or future natural phenomena analyses for the Oak Ridge Y-12 Plant. This approach is being followed in order to develop input to assess that the critical facilities were constructed in accordance with the design drawings, that any major configuration changes to the principle structures are identified and that the location of major equipment loadings are defined. This structural walkdown plan is not intended to collect detailed information for the purpose of developing as-built structural drawings or to evaluate equipment or safety system/component interaction. Implementation of this plan is required for the walkdown phase of the Y-12 Plant natural phenomena analyses. The types of walkdowns to be performed in this procedure include: (1) A walkdown based on a sampling approach to collect detailed structural design information relative to member sizes, orientation, connection, and base details to support the conclusion that the structural configuration is consistent with the design drawings. (2) A walkdown to collect detailed information relative to equipment loadings on top and bottom of floors and roof. (3) A walkthrough inspection of all areas of the building to identify any areas of major configuration change from design drawings. Basic floor loading information such as size, location, and weight is to be obtained. Actual dead loads and live loads are to be determined. Floor load drawings will be developed to show the location, weights, etc., for major dead and live loads. One walkdown package will be generated for each of the following Y-12 Plant structures: Buildings 9212, 9980, 9996, 9723-25, 9828-1, 9828-2, 9828-3, 9767-10, 9812, 9815, 9818, 9999, 9423. The justification for these walkdowns is the potential for release of radioactive and/or other hazardous materials.

  13. Toxicity of 2,4-dinitrotoluene to terrestrial plants in natural soils.

    Science.gov (United States)

    Rocheleau, Sylvie; Kuperman, Roman G; Simini, Mike; Hawari, Jalal; Checkai, Ronald T; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I

    2010-07-15

    The presence of energetic materials (used as explosives and propellants) at contaminated sites is a growing international issue, particularly with respect to military base closures and demilitarization policies. Improved understanding of the ecotoxicological effects of these materials is needed in order to accurately assess the potential exposure risks and impacts on the environment and its ecosystems. We studied the toxicity of the nitroaromatic energetic material 2,4-dinitrotoluene (2,4-DNT) on alfalfa (Medicago sativa L.), barnyard grass (Echinochloa crusgalli L. Beauv.), and perennial ryegrass (Lolium perenne L.) using four natural soils varying in properties (organic matter, clay content, and pH) that were hypothesized to affect chemical bioavailability and toxicity. Amended soils were subjected to natural light conditions, and wetting and drying cycles in a greenhouse for 13 weeks prior to toxicity testing to approximate field exposure conditions in terms of bioavailability, transformation, and degradation of 2,4-DNT. Definitive toxicity tests were performed according to standard protocols. The median effective concentration (EC(50)) values for shoot dry mass ranged from 8 to 229 mg kg(-1), depending on the plant species and soil type. Data indicated that 2,4-DNT was most toxic in the Sassafras (SSL) and Teller (TSL) sandy loam soils, with EC(50) values for shoot dry mass ranging between 8 to 44 mg kg(-1), and least toxic in the Webster clay loam soil, with EC(50) values for shoot dry mass ranging between 40 to 229 mg kg(-1). The toxicity of 2,4-DNT for each of the plant species was significantly (p < or = 0.05) and inversely correlated with the soil organic matter content. Toxicity benchmark values determined in the present studies for 2,4-DNT weathered-and-aged in SSL or TSL soils will contribute to development of an Ecological Soil Screening Level for terrestrial plants that can be used for ecological risk assessment at contaminated sites.

  14. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots

    Science.gov (United States)

    Powell, C. L.; Goltz, M. N.; Agrawal, A.

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~ 1.9 mg L- 1, and initial aqueous [CAH] ~ 150 μg L- 1; cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12 ± 0.01 and 0.59 ± 0.07 d- 1, respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

  15. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots.

    Science.gov (United States)

    Powell, C L; Goltz, M N; Agrawal, A

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~1.9mgL(-1), and initial aqueous [CAH] ~150μgL(-1); cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12±0.01 and 0.59±0.07d(-1), respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

  16. Food Enzymes

    Science.gov (United States)

    McBroom, Rachel; Oliver-Hoyo, Maria T.

    2007-01-01

    Many students view biology and chemistry as two unrelated, separate sciences; how these courses are generally taught in high schools may do little to change that impression. The study of enzymes provide a great opportunity for both biology and chemistry teachers to share with students the interdisciplinary nature of science. This article describes…

  17. Food Enzymes

    Science.gov (United States)

    McBroom, Rachel; Oliver-Hoyo, Maria T.

    2007-01-01

    Many students view biology and chemistry as two unrelated, separate sciences; how these courses are generally taught in high schools may do little to change that impression. The study of enzymes provide a great opportunity for both biology and chemistry teachers to share with students the interdisciplinary nature of science. This article describes…

  18. Natural attenuation potential of tricholoroethene in wetland plant roots: role of native ammonium-oxidizing microorganisms.

    Science.gov (United States)

    Qin, Ke; Struckhoff, Garrett C; Agrawal, Abinash; Shelley, Michael L; Dong, Hailiang

    2015-01-01

    Bench-scale microcosms with wetland plant roots were investigated to characterize the microbial contributions to contaminant degradation of trichloroethene (TCE) with ammonium. The batch system microcosms consisted of a known mass of wetland plant roots in aerobic growth media where the roots provided both an inoculum of root-associated ammonium-oxidizing microorganisms and a microbial habitat. Aqueous growth media, ammonium, and TCE were replaced weekly in batch microcosms while retaining roots and root-associated biomass. Molecular biology results indicated that ammonium-oxidizing bacteria (AOB) were enriched from wetland plant roots while analysis of contaminant and oxygen concentrations showed that those microorganisms can degrade TCE by aerobic cometabolism. Cometabolism of TCE, at 29 and 46 μg L(-1), was sustainable over the course of 9 weeks, with 20-30 mg L(-1) ammonium-N. However, at 69 μg L(-1) of TCE, ammonium oxidation and TCE cometabolism were completely deactivated in two weeks. This indicated that between 46 and 69 μg L(-1) TCE with 30 mg L(-1) ammonium-N there is a threshold [TCE] below which sustainable cometabolism can be maintained with ammonium as the primary substrate. However, cometabolism-induced microbial deactivation of ammonium oxidation and TCE degradation at 69 μg L(-1) TCE did not result in a lower abundance of the amoA gene in the microcosms, suggesting that the capacity to recover from TCE inhibition was still intact, given time and removal of stress. Our study indicates that microorganisms associated with wetland plant roots can assist in the natural attenuation of TCE in contaminated aquatic environments, such as urban or treatment wetlands, and wetlands impacted by industrial solvents.

  19. Natural compounds isolated from Brazilian plants are potent inhibitors of hepatitis C virus replication in vitro.

    Science.gov (United States)

    Jardim, A C G; Igloi, Z; Shimizu, J F; Santos, V A F F M; Felippe, L G; Mazzeu, B F; Amako, Y; Furlan, M; Harris, M; Rahal, P

    2015-03-01

    Compounds extracted from plants can provide an alternative approach to new therapies. They present characteristics such as high chemical diversity, lower cost of production and milder or inexistent side effects compared with conventional treatment. The Brazilian flora represents a vast, largely untapped, resource of potential antiviral compounds. In this study, we investigate the antiviral effects of a panel of natural compounds isolated from Brazilian plants species on hepatitis C virus (HCV) genome replication. To do this we used firefly luciferase-based HCV sub-genomic replicons of genotypes 2a (JFH-1), 1b and 3a and the compounds were assessed for their effects on both HCV replication and cellular toxicity. Initial screening of compounds was performed using the maximum non-toxic concentration and 4 compounds that exhibited a useful therapeutic index (favourable ratio of cytotoxicity to antiviral potency) were selected for extra analysis. The compounds APS (EC50=2.3μM), a natural alkaloid isolated from Maytrenus ilicifolia, and the lignans 3(∗)43 (EC50=4.0μM), 3(∗)20 (EC50=8.2μM) and 5(∗)362 (EC50=38.9μM) from Peperomia blanda dramatically inhibited HCV replication as judged by reductions in luciferase activity and HCV protein expression in both the subgenomic and infectious systems. We further show that these compounds are active against a daclatasvir resistance mutant subgenomic replicon. Consistent with inhibition of genome replication, production of infectious JFH-1 virus was significantly reduced by all 4 compounds. These data are the first description of Brazilian natural compounds possessing anti-HCV activity and further analyses are being performed in order to investigate the mode of action of those compounds.

  20. Antioxidant and antimicrobial effect of some natural plant extracts added to lamb patties during storage

    Directory of Open Access Journals (Sweden)

    Ibrahim, Hayam M.

    2011-06-01

    Full Text Available Natural plants are considered an important target to investigate in order to provide a new source of natural antioxidants and/or antimicrobial agents. The optimum concentrations of some natural plant (jojoba, jatropha, ginseng and ginger extracts were determined and added to lamb patties. Some chemical and microbial characteristics of the prepared patties during storage for 9 days at 4°C were evaluated. Both the addition of these extracts and storage time had a significant effect on the patties throughout the storage period. The effectiveness of the tested natural extracts can be listed in the following order of decreasing Thiobarbituric acid reactive substance (TBARS values: ginseng > jatropha > jojoba > ginger. Aerobic plate count, mould and yeast counts decreased significantly with addition of the extracts during the storage period. Also, the addition of the extracts was significantly effective in reducing histamine, tyramine and putrescine formation during the storage period. Compared to control patties, the addition of these natural extracts was effective as antioxidant and antimicrobial agents for improving the properties of lamb patties.

    Las plantas naturales están consideradas como un importante producto donde buscar y encontrar nuevas fuentes de antioxidantes naturales y/o agentes antimicrobianos. La concentración óptima de algunos extractos de plantas naturales (jojoba, jatropha, ginseng y jengibre fueron determinado y añadidas a pasteles de cordero. Algunas características químicas y microbiológicas de los pasteles preparados y almacenados durante 9 días a 4°C fueron evaluados. Tanto la adición de estos extractos como el tiempo de almacenamiento tuvieron un efecto significativo en los pasteles en el periodo de almacenamiento. La efectividad de los extractos naturales ensayados puede ser enumerada en el siguiente orden decreciente de valores de substancias reactivas con el ácido tiobarbitúrico (TBARS: ginseng