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Sample records for acid regenerating plants

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Enrichment of By-Product Materials from Steel Pickling Acid Regeneration Plants (TRP 9942)

    SciTech Connect

    Lu Swan, Delta Ferrites LLC

    2009-09-30

    A new process for manufacturing an enriched, iron-based product (strontium hexaferrite) in existing steel pickling acid regeneration facilities was evaluated. Process enhancements and equipment additions were made to an existing acid regeneration plant to develop and demonstrate (via pilot scale testing and partial-capacity production trials) the viability of a patented method to produce strontium-based compounds that, when mixed with steel pickling acid and roasted, would result in a strontium hexaferrite powder precursor which could then be subjected to further heat treatment in an atmosphere that promotes rapid, relatively low-temperature formation of discrete strontium hexaferrite magnetic domains yielding an enriched iron-based product, strontium hexaferrite, that can be used in manufacturing hard ferrite magnets.

  3. Teflon lined process pumps save over $25,000/yr in acid regeneration plant

    SciTech Connect

    Ross, L.; Gaines, A.

    1982-03-01

    Armco's Eastern Steel Division Works in Ashland, KY includes an acid regeneration plant that uses the spray/roaster process to recover hydrochloric acid and high purity iron oxides from spent pickling liquor. Two centrifugal pumps, one operating and one on standby, were used to pump the corrosive and erosive mixture at 175-200/sup 0/F to the spray nozzles in the roaster. The impeller, casing and other wetted parts were of an acid resistant exotic metal, but the pumps had a service life of only 2 to 3 months. The impellers had to be replaced after about six weeks because of wear that reduced the discharge pressure and impaired the performance of the spray nozzles. Maintaining the pumps and replacing them several times a year was extremely expensive, since each pump cost about $6000. A 3 X 1 1/2 X 8 1/2'' centrifugal pump specifically designed for severe corrosive service was installed on a trial basis in February 1980. The process pump is built to AVS standards and features a 3/16'' thick fluoropolymer liner molded in place to the ductile iron case, and a fully open faced ductile iron impeller encapsulated with fluoropolymer. The pumps have been available for a number of years with liners and impeller coverings of Du Pont's Teflon-FEP fluorocarbon, and the acid regenerating plant has been using them in various corrosive applications since the startup in 1972. The acid regeneration plant is very pleased with the trouble-free performance of the Teflon-FEP lined pumps. They are reliable, essentially maintenance free, and maintain the discharge pressures required for efficient operation of the spray nozzles.

  4. High-performance effluent-free pickling plants with fluid bed hydrochloric acid regeneration

    SciTech Connect

    Rituper, R.

    1995-11-01

    There is perpetual need to increase the performance of production facilities in the steel industry. Cost and product quality advantages, increased productivity and environmental acceptable processing of steel are the most important considerations in today`s highly competitive market. The newly developed Keramchemie strip pickle line, the Vario process, consists of a high-velocity pickling cell comprising a shallow, horizontal channel section that results in a turbulent flow behavior in the pickling section. Optimization of the pickling process is achieved by automatic setting of the pickling parameters such as acid flow and pressure via process control. Spent pickle liquor is completely regenerated in a recovery system using the fluidized bed process. The pickle liquor recycled between the pickling tanks and regeneration unit, results in a nearly zero consumption apart from small evaporation losses. The rinse water is completely reused. This makes an effluent-free operation of the pickling plant possible. No environmental pollution is caused by the pickling process. Some effluent-free strip pickling plants are already in operation in Europe with HCl consumption of less than 0.2 kg/tonne of pickled material.

  5. Plant Thioredoxin CDSP32 Regenerates 1-Cys Methionine Sulfoxide Reductase B Activity through the Direct Reduction of Sulfenic Acid*

    PubMed Central

    Tarrago, Lionel; Laugier, Edith; Zaffagnini, Mirko; Marchand, Christophe H.; Le Maréchal, Pierre; Lemaire, Stéphane D.; Rey, Pascal

    2010-01-01

    Thioredoxins (Trxs) are ubiquitous enzymes catalyzing the reduction of disulfide bonds, thanks to a CXXC active site. Among their substrates, 2-Cys methionine sulfoxide reductases B (2-Cys MSRBs) reduce the R diastereoisomer of methionine sulfoxide (MetSO) and possess two redox-active Cys as follows: a catalytic Cys reducing MetSO and a resolving one, involved in disulfide bridge formation. The other MSRB type, 1-Cys MSRBs, possesses only the catalytic Cys, and their regeneration mechanisms by Trxs remain unclear. The plant plastidial Trx CDSP32 is able to provide 1-Cys MSRB with electrons. CDSP32 includes two Trx modules with one potential active site 219CGPC222 and three extra Cys. Here, we investigated the redox properties of recombinant Arabidopsis CDSP32 and delineated the biochemical mechanisms of MSRB regeneration by CDSP32. Free thiol titration and 4-acetamido-4′-maleimidyldistilbene-2,2′-disulfonic acid alkylation assays indicated that the Trx possesses only two redox-active Cys, very likely the Cys219 and Cys222. Protein electrophoresis analyses coupled to mass spectrometry revealed that CDSP32 forms a heterodimeric complex with MSRB1 via reduction of the sulfenic acid formed on MSRB1 catalytic Cys after MetSO reduction. MSR activity assays using variable CDSP32 amounts revealed that MSRB1 reduction proceeds with a 1:1 stoichiometry, and redox titrations indicated that CDSP32 and MSRB1 possess midpoints potentials of −337 and −328 mV at pH 7.9, respectively, indicating that regeneration of MSRB1 activity by the Trx through sulfenic acid reduction is thermodynamically feasible in physiological conditions. PMID:20236937

  6. Regeneration of Stevia Plant Through Callus Culture

    PubMed Central

    Patel, R. M.; Shah, R. R.

    2009-01-01

    Stevia rebaudiana Bertoni that conventionally propagated by seed or by cuttings or clump division which has a limitation of quality and quantity seed material. In present study, callus culture technique was tried to achieve rapid plant multiplication for quality seed material. Callus induction and multiplication medium was standardized from nodal as well as leaf sagments. It is possible to maintain callus on Murashige and Skoog medium supplemented with 6-benzyl amino purine and naphthalene acetic acid. Maximum callus induction was obtained on Murashige and Skoog medium incorporated with 6-benzyl amino purine (2.0-3.0 mg/l) and naphthalene acetic acid (2.0 mg/l) treatments. However, Murashige and Skoog medium containing 2.0 mg/l 6-benzyl amino purine+2.0 mg/l naphthalene acetic acid was found to be the best for callus induction. Higher regeneration frequency was noticed with Murashige and Skoog medium supplemented with 2.0 mg/l 6-benzyl amino purine+0.2 mg/l naphthalene acetic acid. Regenerated plants were rooted better on ¼ Murashige and Skoog strength supplemented with 0.1 mg/l indole-3-butyric acid. The rooted plantlets were hardened successfully in tera care medium with 63 per cent survival rate. The developed protocol can be utilized for mass production of true to type planting material on large scale independent of season, i.e. external environmental conditions. PMID:20177455

  7. How-To-Do-It: Plant Regeneration.

    ERIC Educational Resources Information Center

    Pietraface, William J.

    1988-01-01

    Describes a procedure for the growth of tobacco plants in flasks. Demonstrates plant tissue culture manipulation, totipotency, and plant regeneration in approximately 12 weeks. Discusses methods, materials, and expected results. (CW)

  8. Plant regeneration: cellular origins and molecular mechanisms.

    PubMed

    Ikeuchi, Momoko; Ogawa, Yoichi; Iwase, Akira; Sugimoto, Keiko

    2016-05-01

    Compared with animals, plants generally possess a high degree of developmental plasticity and display various types of tissue or organ regeneration. This regenerative capacity can be enhanced by exogenously supplied plant hormones in vitro, wherein the balance between auxin and cytokinin determines the developmental fate of regenerating organs. Accumulating evidence suggests that some forms of plant regeneration involve reprogramming of differentiated somatic cells, whereas others are induced through the activation of relatively undifferentiated cells in somatic tissues. We summarize the current understanding of how plants control various types of regeneration and discuss how developmental and environmental constraints influence these regulatory mechanisms. PMID:27143753

  9. In vitro plant regeneration of Aster scaber via somatic embryogenesis.

    PubMed

    Boo, Kyung Hwan; Cao, Dang Viet; Pamplona, Reniel S; Lee, Doseung; Riu, Key-Zung; Lee, Dong-Sun

    2015-01-01

    We established an in vitro plant regeneration system via somatic embryogenesis of Aster scaber, an important source of various biologically active phytochemicals. We examined the callus induction and embryogenic capacities of three explants, including leaves, petioles, and roots, on 25 different media containing different combinations of α-naphthalene acetic acid (NAA) and 6-benzyladenine (BA). The optimum concentrations of NAA and BA for the production of embryogenic calli were 5.0 μM and 0.05 μM, respectively. Media containing higher concentrations of auxin and cytokinin (such as 25 μM NAA and 25 μM BA) were suitable for shoot regeneration, especially for leaf-derived calli, which are the most readily available calli and are highly competent. For root induction from regenerated shoots, supplemental auxin and/or cytokinin did not improve rooting, but instead caused unwanted callus induction or retarded growth of regenerated plants. Therefore, plant growth regulator-free medium was preferable for root induction. Normal plants were successfully obtained from calli under the optimized conditions described above. This is the first report of the complete process of in vitro plant regeneration of A. scaber via somatic embryogenesis. PMID:25640866

  10. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C. Judson; Poole, Loree J.

    1995-01-01

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine.

  11. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C.J.; Poole, L.J.

    1995-05-02

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine. 10 figs.

  12. EYTHYLENE INFLUENCES GREEN PLANT REGENERATION FROM BARLEY CALLUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant hormone ethylene is involved in numerous plant processes including in vitro growth and regeneration. Manipulating ethylene in vitro may be useful for increasing plant regeneration from cultured cells. As part of ongoing efforts to improve plant regeneration from barley (Hordeum vulgare L...

  13. Hyaluronic Acid in Inflammation and Tissue Regeneration.

    PubMed

    Litwiniuk, Malgorzata; Krejner, Alicja; Speyrer, Marcus S; Gauto, Anibal R; Grzela, Tomasz

    2016-03-01

    Hyaluronic acid (HA), the main component of extracellular matrix, is considered one of the key players in the tissue regeneration process. It has been proven to modulate via specific HA receptors, inflammation, cellular migration, and angiogenesis, which are the main phases of wound healing. Studies have revealed that most HA properties depend on its molecular size. High molecular weight HA displays anti-inflammatory and immunosuppressive properties, whereas low molecular weight HA is a potent proinflammatory molecule. In this review, the authors summarize the role of HA polymers of different molecular weight in tissue regeneration and provide a short overview of main cellular receptors involved in HA signaling. In addition, the role of HA in 2 major steps of wound healing is examined: inflammation and the angiogenesis process. Finally, the antioxidative properties of HA are discussed and its possible clinical implication presented. PMID:26978861

  14. Plant fatty acid hydroxylases

    DOEpatents

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

    2001-01-01

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

  15. Utilization of spent coking plant acid

    SciTech Connect

    Vasil'eva, I.V.; Vasilenko, N.Y.; Mostovaya, V.G.; Tret'yak, N.K.

    1983-01-01

    A feasibility study is described for using spent regenerated sulfuric acid from a coking plant, containing 540-640 g/l H/sub 2/SO/sub 4/, to pickle metals. Results were compared with the performance of a solution of technical sulfuric acid in pickling high-carbon and low-alloy steels. It was found economically feasible to use the spent regenerated acid as the basic pickling solution. The degree of protection of the metal against corrosion is 85%, which can be increased to 98-99% if inhibitors are added to the acid. Only one-fifth as much inhibitor is needed with the regenerated acid as with the technical sulfuric acid.

  16. Competence and regulatory interactions during regeneration in plants

    PubMed Central

    Pulianmackal, Ajai J.; Kareem, Abdul V. K.; Durgaprasad, Kavya; Trivedi, Zankhana B.; Prasad, Kalika

    2014-01-01

    The ability to regenerate is widely exploited by multitudes of organisms ranging from unicellular bacteria to multicellular plants for their propagation and repair. But the levels of competence for regeneration vary from species to species. While variety of living cells of a plant display regeneration ability, only a few set of cells maintain their stemness in mammals. This highly pliable nature of plant cells in-terms of regeneration can be attributed to their high developmental plasticity. De novo organ initiation can be relatively easily achieved in plants by proper hormonal regulations. Elevated levels of plant hormone auxin induces the formation of proliferating mass of pluripotent cells called callus, which predominantly express lateral root meristem markers and hence is having an identity similar to lateral root primordia. Organ formation can be induced from the callus by modulating the ratio of hormones. An alternative for de novo organogenesis is by the forced expression of plant specific transcription factors. The mechanisms by which plant cells attain competence for regeneration on hormonal treatment or forced expression remain largely elusive. Recent studies have provided some insight into how the epigenetic modifications in plants affect this competence. In this review we discuss the present understanding of regenerative biology in plants and scrutinize the future prospectives of this topic. While discussing about the regeneration in the sporophyte of angiosperms which is well studied, here we outline the regenerative biology of the gametophytic phase and discuss about various strategies of regeneration that have evolved in the domain of life so that a common consensus on the entire process of regeneration can be made. PMID:24782880

  17. Approaches for regeneration of amine-carboxylic acid extracts

    SciTech Connect

    Dai, Y.; King, C.J.

    1995-07-01

    Extraction processes based on reversible chemical complexation can be useful for separation of polar organics from dilute solution. Tertiary amines are effective extractants for the recovery of carboxylic acids from aqueous solution. The regeneration of aminecarboxylic acid extracts is an important step which strongly influences the economic viability of the separation process. Several regeneration methods are critically reviewed, and the factors that affect swing regeneration processes, including temperature-swing, diluent composition-swing and pH-swing with a volatile base are discussed. Interest in this area comes from interest in treatment of waste streams, particularly in petrochemical and fermentation manufacture.

  18. Somatic Embryogenesis and Plant Regeneration of Brachiaria brizantha.

    PubMed

    Cabral, Glaucia B; Carneiro, Vera T C; Dusi, Diva M A; Martinelli, Adriana P

    2016-01-01

    The genus Brachiaria (Trin.) Griseb. belongs to the family Poaceae, order Poales, class Monocotyledonae. In Brachiaria brizantha (Hochst. ex A. Rich.) Stapf., embryogenic callus can be induced from seeds from apomictic plants, which results in high frequency somatic embryo development and plant regeneration. We report here a detailed protocol for callus induction from apomictic seed; followed by in vitro morphogenesis (somatic embryo and bud differentiation), plant regeneration, and acclimatization in the greenhouse. Important details regarding the positioning of seeds for callus induction and precautions to avoid endophytic contamination and the occurrence of albino plants are presented. PMID:26619875

  19. In Vitro Regeneration of Endangered Medicinal Plant Heliotropium kotschyi (Ramram).

    PubMed

    Sadeq, Manal Ahmed; Pathak, Malabika Roy; Salih, Ahmed Ali; Abido, Mohammed; Abahussain, Asma

    2016-01-01

    Heliotropium kotschyi (Ramram) is an important endangered medicinal plant distributed in the Kingdom of Bahrain. Plant tissue culture technique is applied for ex situ conservation study. Nodal stem segments are cultured in modified MS media supplemented with various combination and concentration of plant growth regulators (PGRs). Plants are regenerated via shoot organogenesis from the nodal meristems. Plants are regenerated in three different steps: initial shoot development, shoot multiplication, and rooting. After 4 weeks of culture, 100 % explants respond to shoot initiation on the medium containing 8.88 μM BAP and 5.71 μM IAA. The highest frequency of shoot regeneration is observed in the same media after second subculture of shoots. The highest rooting frequency is observed in the presence of 2.85 μM IAA. After root development, the plantlets are transferred to pots filled with soil and 60 % of plants survived after 45 days. This plant regeneration protocol is of great value for rapid desert plant propagation program. PMID:27108312

  20. Plant regeneration from immature inflorescence derived callus cultures of salt tolerant kallar grass (Leptochloa fusca L.).

    PubMed

    Praveena, M; Giri, C C

    2012-10-01

    Efficient plant regeneration has been achieved from immature inflorescence derived callus cultures of salt tolerant grass Leptochloa fusca (L.). Young inflorescence explants displayed wide-ranging responses for callus induction and plant regeneration when subjected to different cold treatment durations and without cold treatment exposure (control) prior to its inoculation to MS medium supplemented with different concentrations/combinations of plant growth regulators (PGRs). The PGRs included auxins: 2, 4-dichlorophenoxy acetic acid (2, 4-D), picloram (Pic), 3, 6-dichloro-2-methoxy benzoic acid (dicamba) and cytokinins: Kinetin (KN), N6-benzyl adenine (BA). These treatments promoted different callus induction frequencies as well as various callus types such as type 1, type 2 and type 3. Induction of type 2 callus (white and compact) with potential for regeneration was obtained from cold treated (3 days at 10 °C) immature inflorescence cultured on MS medium containing 2.0 mg/l dicamba and 0.25 mg/l BA. The study demonstrated that 2.0 mg/l dicamba and 0.25 mg/l BA induced callus promoted improved frequency compared to zilch shoot regeneration response with other combinations involving 2, 4-D, picloram, KN and BA. Full strength MS supplemented with 2.0 mg/l NAA and 0.5 mg/l BA was found to be optimal for plant regeneration. The regeneration frequencies ranged from 13.8 ± 1.366 to 55.5 ± 2.766 with highest number of shoots (19.1 ± 0.560) per 50-60 mg of callus as explants after 28 days of inoculation. Plant regeneration was also obtained on the dicamba callus induction medium itself within 21 days inoculation of immature inflorescence explants. Half strength MS medium both semisolid and liquid devoid of plant growth regulators promoted highest frequency (92.8 ± 4.099 and 100 ± 0.00) of rooting in regenerated shoots. Plants with well developed roots were successfully transferred to pots and grown to maturity with normal flowering and

  1. Retinoic Acid Stimulates Regeneration of Mammalian Auditory Hair Cells

    NASA Astrophysics Data System (ADS)

    Lefebvre, Philippe P.; Malgrange, Brigitte; Staecker, Hinrich; Moonen, Gustave; van de Water, Thomas R.

    1993-04-01

    Sensorineural hearing loss resulting from the loss of auditory hair cells is thought to be irreversible in mammals. This study provides evidence that retinoic acid can stimulate the regeneration in vitro of mammalian auditory hair cells in ototoxic-poisoned organ of Corti explants in the rat. In contrast, treatment with retinoic acid does not stimulate the formation of extra hair cells in control cultures of Corti's organ. Retinoic acid-stimulated hair cell regeneration can be blocked by cytosine arabinoside, which suggests that a period of mitosis is required for the regeneration of auditory hair cells in this system. These results provide hope for a recovery of hearing function in mammals after auditory hair cell damage.

  2. Regeneration of fertile green plants from oat isolated microspore culture.

    PubMed

    Sidhu, Parminder K; Davies, Philip A

    2009-04-01

    Regeneration of fertile green plants from isolated oat microspores is reported for the first time. Factors critical for microspore growth and regeneration include cold pre-treatment, pH of culture medium and the use of conditioned culture medium. It was found that cold pre-treatment at 4 degrees C in the dark for a minimum of 6 weeks was necessary to consistently achieve microspore growth into multicellular structures (MCS). Longer pre-treatments of up to 9 weeks were tested and found to be positively correlated with the number of MCS produced. Microspore culture medium with pH 8.0 produced significantly more MCS larger than eight cells in size than media with pH 5.8. The use of medium conditioned by actively growing barley microspores significantly increased the numbers of MCS larger than eight cells in size compared to non-conditioned media. Plants were regenerated only from cultures using conditioned medium. A total of 2 green plants and 15 albinos were regenerated. Of the green plants, one had the haploid chromosome complement (n = 3x = 21) and the other had the parental hexaploid chromosome complement (2n = 6x = 42) which may be due to spontaneous chromosome doubling. The hexaploid plant set seed naturally and the haploid plant set seed after its chromosome complement was doubled with colchicine. PMID:19247663

  3. Mitragyna speciosa: hairy root culture for triterpenoid production and high yield of mitragynine by regenerated plants.

    PubMed

    Phongprueksapattana, Siriwan; Putalun, Waraporn; Keawpradub, Niwat; Wungsintaweekul, Juraithip

    2008-01-01

    Hairy root cultures of Mitragyna speciosa were established by infection of Agrobacterium rhizogenes ATCC 15834 and maintained in McCown woody plant medium (WPM) supplemented with 0.5 mg/1 naphthaleneacetic acid. The hairy roots were identified for the rooting genes loci of rolA and rolB by polymerase chain reaction. For studying the secondary metabolite production, the n-hexane extract of the hairy roots was prepared and the compounds were isolated by silica gel column chromatography, affording triterpenoids (ursolic acid and oleanolic acid) and phytosterols (beta-sitosterol and stigmasterol). The shoots from the hairy root cultures were regenerated and differentiated to the plantlets. For micropropagation, shoot multiplication was successfully induced from the axillary buds of the regenerated plantlets in WPM supplemented with 0.1 mg/l thidiazuron. The mitragynine contents of 5-month-old regenerated plants and in vitro plantlets (germinated from seeds) were determined using the TLC-densitometric method. The regenerated plants contained (14.25 +/- 0.25) mg/g dry wt mitragynine, whereas the in vitro plantlets contained (4.45 +/- 0.09) mg/g dry wt. PMID:19040109

  4. Vegetative Regeneration Capacities of Five Ornamental Plant Invaders After Shredding

    NASA Astrophysics Data System (ADS)

    Monty, Arnaud; Eugène, Marie; Mahy, Grégory

    2015-02-01

    Vegetation management often involves shredding to dispose of cut plant material or to destroy the vegetation itself. In the case of invasive plants, this can represent an environmental risk if the shredded material exhibits vegetative regeneration capacities. We tested the effect of shredding on aboveground and below-ground vegetative material of five ornamental widespread invaders in Western Europe that are likely to be managed by cutting and shredding techniques: Buddleja davidii (butterfly bush, Scrophulariaceae), Fallopia japonica (Japanese knotweed, Polygonaceae), Spiraea × billardii Hérincq (Billard's bridewort, Rosaceae), Solidago gigantea (giant goldenrod, Asteraceae), and Rhus typhina L. (staghorn sumac, Anacardiaceae). We looked at signs of vegetative regeneration and biomass production, and analyzed the data with respect to the season of plant cutting (spring vs summer), the type of plant material (aboveground vs below-ground), and the shredding treatment (shredded vs control). All species were capable of vegetative regeneration, especially the below-ground material. We found differences among species, but the regeneration potential was generally still present after shredding despite a reduction of growth rates. Although it should not be excluded in all cases (e.g., destruction of giant goldenrod and staghorn sumac aboveground material), the use of a shredder to destroy woody alien plant material cannot be considered as a general management option without significant environmental risk.

  5. Plant fatty acid hydroxylase

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    2000-01-01

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

  6. Externally imposed electric field enhances plant root tip regeneration.

    PubMed

    Kral, Nicolas; Hanna Ougolnikova, Alexandra; Sena, Giovanni

    2016-06-01

    In plants, shoot and root regeneration can be induced in the distinctive conditions of tissue culture (in vitro) but is also observed in intact individuals (in planta) recovering from tissue damage. Roots, for example, can regenerate their fully excised meristems in planta, even in mutants with impaired apical stem cell niches. Unfortunately, to date a comprehensive understanding of regeneration in plants is still missing. Here, we provide evidence that an imposed electric field can perturb apical root regeneration in Arabidopsis. Crucially, we explored both spatial and temporal competences of the stump to respond to electrical stimulation, by varying respectively the position of the cut and the time interval between excision and stimulation. Our data indicate that a brief pulse of an electric field parallel to the root is sufficient to increase by up to two-fold the probability of its regeneration, and to perturb the local distribution of the hormone auxin, as well as cell division regulation. Remarkably, the orientation of the root towards the anode or the cathode is shown to play a role. PMID:27606066

  7. Externally imposed electric field enhances plant root tip regeneration

    PubMed Central

    Kral, Nicolas; Hanna Ougolnikova, Alexandra

    2016-01-01

    Abstract In plants, shoot and root regeneration can be induced in the distinctive conditions of tissue culture (in vitro) but is also observed in intact individuals (in planta) recovering from tissue damage. Roots, for example, can regenerate their fully excised meristems in planta, even in mutants with impaired apical stem cell niches. Unfortunately, to date a comprehensive understanding of regeneration in plants is still missing. Here, we provide evidence that an imposed electric field can perturb apical root regeneration in Arabidopsis. Crucially, we explored both spatial and temporal competences of the stump to respond to electrical stimulation, by varying respectively the position of the cut and the time interval between excision and stimulation. Our data indicate that a brief pulse of an electric field parallel to the root is sufficient to increase by up to two‐fold the probability of its regeneration, and to perturb the local distribution of the hormone auxin, as well as cell division regulation. Remarkably, the orientation of the root towards the anode or the cathode is shown to play a role. PMID:27606066

  8. Phenotypic variation in plants regenerated from protoplasts: the potato system

    SciTech Connect

    Bidney, D.L.; Shepard, J.F.

    1981-12-01

    Regeneration of whole plants from isolated protoplasts (plant cells devoid of cell walls) provides a novel capability that is potentially useful for crop improvement efforts. Such a regeneration capacity has been developed for the commercial potato cultivar 'russet Burbank,' currently the most popular cultivar in production. Due to fertility problems of this cultivar, the improvement of 'russet Burbank' by classical breeding procedures has been limited. Examination of a large population of protoplast-derived clones has revealed that variation for a number of traits can be observed. Variation observed under laboratory conditions and in field trials includes changes in plant morphology and tuber-setting characteristics, as well as alterations in response to environmental and pathogen stress. A brief description of the cloning process and the potential for application of cloning technology in crop plant improvement will be presented. (Refs. 41).

  9. Regeneration of ascorbic acid in human placenta

    SciTech Connect

    Rose, R.C.; Bode, A.M. )

    1990-02-26

    The free radical scavenging function of ascorbic acid (AA) results in the formation of the oxidized form of the vitamin, dehydro-L-ascorbic acid (DHAA). The enzymatic reduction of DHAA may be an important means of recycling and conserving ascorbic acid in various tissues. The role of the human placenta in the enzymatic reduction of the potentially toxic oxidized form was examined in tissue homogenized in 50 mM MOPs buffer. Assay of DHAA, AA, DKG (diketogulonic acid) were made by HPLC and liquid scintillation counting. Activity of the placental factor in reducing DHAA was dependent on the presence of both NADPH and GSH. Activity was reduced 81% by incubation with 2% trypsin and was unaffected by BSA, glycerol, EtOH, or Na-AZIDE. Inhibition was observed with 10 mM EDTA and 0.2M KCI but not with 1 mM EDTA or 0.1 M KCI or less. Studies are underway to further purify and characterize the enzyme(s) responsible for the observed activity.

  10. Retinoic acid regulation by CYP26 in vertebrate lens regeneration

    PubMed Central

    Thomas, Alvin G; Henry, Jonathan J

    2014-01-01

    Xenopus laevis is among the few species that are capable of fully regenerating a lost lens de novo. This occurs upon removal of the lens, when secreted factors from the retina are permitted to reach the cornea epithelium and trigger it to form a new lens. Although many studies have investigated the retinal factors that initiate lens regeneration, relatively little is known about what factors support this process and make the cornea competent to form a lens. We presently investigate the role of Retinoic acid (RA) signaling in lens regeneration in Xenopus. RA is a highly important morphogen during vertebrate development, including the development of various eye tissues, and has been previously implicated in several regenerative processes as well. For instance, Wolffian lens regeneration in the newt requires active RA signaling. In contrast, we provide evidence here that lens regeneration in Xenopus actually depends on the attenuation of RA signaling, which is regulated by the RA-degrading enzyme CYP26. Using RTPCR we examined the expression of RA synthesis and metabolism related genes within ocular tissues. We found expression of aldh1a1, aldh1a2, and aldh1a3, as well as cyp26a1 and cyp26b1 in both normal and regenerating corneal tissue. On the other hand, cyp26c1 does not appear to be expressed in either control or regenerating corneas, but it is expressed in the lens. Additionally in the lens, we found expression of aldh1a1 and aldh1a2, but not aldh1a3. Using an inhibitor of CYP26, and separately using exogenous retinoids, as well as RA signaling inhibitors, we demonstrate that CYP26 activity is necessary for lens regeneration to occur. We also find using phosphorylated Histone H3 labeling that CYP26 antagonism reduces cell proliferation in the cornea, and using qPCR we find that exogenous retinoids alter the expression of putative corneal stem cell markers. Furthermore, the Xenopus cornea is composed of an outer layer and inner basal epithelium, as well as a

  11. Plant regeneration through callus organogenesis and true-to-type conformity of plants by RAPD analysis in Desmodium gangeticum (Linn.) DC.

    PubMed

    Cheruvathur, Meena K; Abraham, Jyothi; Thomas, T Dennis

    2013-03-01

    An efficient plant regeneration protocol was established for an endangered ethnomedicinal plant Desmodium gangeticum (Linn.) DC. Morphogenic calli were produced from 96 % of the cultures comprising the immature leaf explants on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (4.0 mg l(-1)) in combination with 6-benzylaminopurine (BA; 0.8 mg l(-1)). For callus regeneration, various concentrations of BA (1.0-5.0 mg l(-1)) or thidiazuron (TDZ; 1.0-5.0 mg l(-1)) alone or in combination with indole-3-acetic acid (IAA; 0.2-1.0 mg l(-1)) were used. Highest response of shoot regeneration was observed on MS medium fortified with TDZ (4.0 mg l(-1)) and IAA (0.5 mg l(-1)) combination. Here, 100 % cultures responded with an average number of 22.3 shoots per gram calli. Inclusion of indole-3-butyric acid in half MS medium favored rooting of recovered shoots. Out of 45 rooted plants transferred to soil, 40 survived. Total DNA was extracted from the leaves of the acclimatized plants of D. gangeticum. Analysis of random amplified polymorphic DNA using 13 arbitrary decanucleotide primers showed the genetic homogeneity in all the ten plants regenerated from callus with parental plant, suggesting that shoot regeneration from callus could be used for the true-to-type multiplication of this plant. PMID:23340869

  12. Regeneration of viable oil palm plants from protoplasts by optimizing media components, growth regulators and cultivation procedures.

    PubMed

    Masani, Mat Yunus Abdul; Noll, Gundula; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk

    2013-09-01

    Oil palm protoplasts are suitable as a starting material for the production of oil palm plants with new traits using approaches such as somatic hybridization, but attempts to regenerate viable plants from protoplasts have failed thus far. Here we demonstrate, for the first time, the regeneration of viable plants from protoplasts isolated from cell suspension cultures. We achieved a protoplast yield of 1.14×10(6) per gram fresh weight with a viability of 82% by incubating the callus in a digestion solution comprising 2% cellulase, 1% pectinase, 0.5% cellulase onuzuka R10, 0.1% pectolyase Y23, 3% KCl, 0.5% CaCl2 and 3.6% mannitol. The regeneration of protoplasts into viable plants required media optimization, the inclusion of plant growth regulators and the correct culture technique. Microcalli derived from protoplasts were obtained by establishing agarose bead cultures using Y3A medium supplemented with 10μM naphthalene acetic acid, 2μM 2,4-dichlorophenoxyacetic acid, 2μM indole-3-butyric acid, 2μM gibberellic acid and 2μM 2-γ-dimethylallylaminopurine. Small plantlets were regenerated from microcalli by somatic embryogenesis after successive subculturing steps in medium with limiting amounts of growth regulators supplemented with 200mg/l ascorbic acid. PMID:23849119

  13. Planting machine system for forest regeneration

    SciTech Connect

    Fridley, R.B.; Johnson, N.K.

    1985-01-01

    An experimental machine was developed to evaluate the effectiveness of components for intermittent planting of tree seedlings. Components tested included (a) a linkage to allow finite duration contact of the planking head with the ground, (b) pneumatics to convey seedlings to a front-opening, pivot-gate dibble, (c) plunger packers to move soil along the shear plane for compaction, and (d) seedlings with their roots encapsulated in a biomass medium to contain the roots in proper orientation and also provide a uniform size and shape for high-speed automatic handling. The experimental machine was demonstrated at a ground speed of 3.5 km/h at a 3 m intrarow spacing. 12 references.

  14. Slicing across Kingdoms: Regeneration in Plants and Animals

    PubMed Central

    Birnbaum, Kenneth D.; Alvarado, Alejandro Sánchez

    2009-01-01

    Multicellular organisms possessing relatively long life spans are subjected to diverse, constant, and often intense intrinsic and extrinsic challenges to their survival. Animal and plant tissues wear out as part of normal physiological functions and can be lost to predators, disease, and injury. Both kingdoms survive this wide variety of insults by strategies that include the maintenance of adult stem cells or the induction of stem cell potential in differentiated cells. Repatterning mechanisms often deploy embryonic genes, but the question remains in both plants and animals whether regeneration invokes embryogenesis, generic patterning mechanisms, or unique circuitry comprised of well-established patterning genes. PMID:18295584

  15. Efficient in vitro regeneration of fertile plants from corm explants of Hypoxis hemerocallidea landrace Gaza -- the "African Potato".

    PubMed

    Ndong, Yves Assoumou; Wadouachi, Anne; Sangwan-Norreel, Brigitte S; Sangwan, Rajbir S

    2006-04-01

    We present efficient protocols for the regeneration of fertile plants from corm explants of Hypoxis hemerocallidea Fisch. and C. A. Mey. landrace Gaza, either by direct multiple shoot formation or via shoot organogenesis from corm-derived calluses. The regeneration efficiency depended on plant growth regulator concentrations and combinations. Multiple direct shoot formation with high frequency (100% with 5-8 shoots/explant) was obtained on a basal medium (BM) supplemented with 3 mg/l kinetin (BM1). However, efficient indirect regeneration occurred when corm explants were first plated on callus induction medium (BM2) with high kinetin (3 mg/l) and naphthalene acetic acid (NAA 1 mg/l), and then transferred to shoot inducing medium (BM3) containing BA (1.5 mg/l) and NAA (0.5 mg/l). Shoot regeneration frequency was 100% and 30-35 shoots per explant were obtained. The regenerated shoots were rooted on a root inducing medium (BM4) containing NAA (0.1 mg/l). Rooted plantlets were transferred to the greenhouse. The regenerants were morphologically normal and fertile. Flow cytometric analyses and chloroplast counts of guard cells suggested that the regenerants were diploid. Efficient cloning protocols described here, have the potential not only to substantially reduce the pressure on natural populations but also for wider biotechnological applications of Hypoxis hemerocallidea-an endangered medicinal plant. PMID:16222532

  16. Protocols to determine pollination requirements and optimal pollinators for plant genetic resource regeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guidelines have been established for the maintenance of plant genetic resource collections, including seed regeneration. When carefully conducted, regeneration is a key tool in germplasm conservation, helping reduce the negative effects of genetic erosion. However, inadequate knowledge of basic p...

  17. Shoot Organogenesis and Plant Regeneration from Leaf Explants of Lysionotus serratus D. Don

    PubMed Central

    Deng, Min; Zhao, Wei; Song, Yigang; Li, Quanjian; Huang, Qingjun

    2013-01-01

    The gesneriaceous perennial plant, Lysionotus serratus, has been used in traditional Chinese medicine. It also has a great development potential as an ornamental plant with its attractive foliage and beautiful flowers. An efficient propagation and regeneration system via direct shoot organogenesis from leaf explant was established in this study. High active cytokinin (6-benzyladenine (BA) or thidiazuron (TDZ)) was effective for direct organogenesis of initial induction. Murashige and Skoog (MS) growth media containing 0.5 mg L−1 BA alone or with combination of 0.1 mg L−1  α-Naphthaleneacetic acid (NAA) were the most effective for shoot proliferation. High BA concentration (1.0 mg L−1) in the media caused high percentage of vitrified shoots though they introduced high shoot proliferation rate. Histological observation indicated that adventitious shoot regeneration on the medium containing 0.5 mg L−1 BA alone occurred directly from leaf epidermal cells without callus formation. Regenerated shoots rooted well on medium containing half-strength MS medium with 0.5 mg L−1 indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA), and the plantlets successfully acclimatized and grew vigorously in the greenhouse with a 94.2% and 92.1% survival rate. PMID:23983626

  18. Plants for water recycling, oxygen regeneration and food production.

    PubMed

    Bubenheim, D L

    1991-10-01

    During long-duration space missions that require recycling and regeneration of life support materials the major human wastes to be converted to usable forms are CO2, hygiene water, urine and feces. A Controlled Ecological Life Support System (CELSS) relies on the air revitalization, water purification and food production capabilities of higher plants to rejuvenate human wastes and replenish the life support materials. The key processes in such a system are photosynthesis, whereby green plants utilize light energy to produce food and oxygen while removing CO2 from the atmosphere, and transpiration, the evaporation of water from the plant. CELSS research has emphasized the food production capacity and efforts to minimize the area/volume of higher plants required to satisfy all human life support needs. Plants are a dynamic system capable of being manipulated to favour the supply of individual products as desired. The size and energy required for a CELSS that provides virtually all human needs are determined by the food production capacity. Growing conditions maximizing food production do not maximize transpiration of water; conditions favoring transpiration and scaling to recycle only water significantly reduces the area, volume, and energy inputs per person. Likewise, system size can be adjusted to satisfy the air regeneration needs. Requirements of a waste management system supplying inputs to maintain maximum plant productivity are clear. The ability of plants to play an active role in waste processing and the consequence in terms of degraded plant performance are not well characterized. Plant-based life support systems represent the only potential for self sufficiency and food production in an extra-terrestrial habitat. PMID:11537696

  19. Plants for water recycling, oxygen regeneration and food production

    NASA Technical Reports Server (NTRS)

    Bubenheim, D. L.

    1991-01-01

    During long-duration space missions that require recycling and regeneration of life support materials the major human wastes to be converted to usable forms are CO2, hygiene water, urine and feces. A Controlled Ecological Life Support System (CELSS) relies on the air revitalization, water purification and food production capabilities of higher plants to rejuvenate human wastes and replenish the life support materials. The key processes in such a system are photosynthesis, whereby green plants utilize light energy to produce food and oxygen while removing CO2 from the atmosphere, and transpiration, the evaporation of water from the plant. CELSS research has emphasized the food production capacity and efforts to minimize the area/volume of higher plants required to satisfy all human life support needs. Plants are a dynamic system capable of being manipulated to favour the supply of individual products as desired. The size and energy required for a CELSS that provides virtually all human needs are determined by the food production capacity. Growing conditions maximizing food production do not maximize transpiration of water; conditions favoring transpiration and scaling to recycle only water significantly reduces the area, volume, and energy inputs per person. Likewise, system size can be adjusted to satisfy the air regeneration needs. Requirements of a waste management system supplying inputs to maintain maximum plant productivity are clear. The ability of plants to play an active role in waste processing and the consequence in terms of degraded plant performance are not well characterized. Plant-based life support systems represent the only potential for self sufficiency and food production in an extra-terrestrial habitat.

  20. Regeneration niche differentiates functional strategies of desert woody plant species

    PubMed Central

    Briggs, John M.

    2010-01-01

    Plant communities vary dramatically in the number and relative abundance of species that exhibit facilitative interactions, which contributes substantially to variation in community structure and dynamics. Predicting species’ responses to neighbors based on readily measurable functional traits would provide important insight into the factors that structure plant communities. We measured a suite of functional traits on seedlings of 20 species and mature plants of 54 species of shrubs from three arid biogeographic regions. We hypothesized that species with different regeneration niches—those that require nurse plants for establishment (beneficiaries) versus those that do not (colonizers)—are functionally different. Indeed, seedlings of beneficiary species had lower relative growth rates, larger seeds and final biomass, allocated biomass toward roots and height at a cost to leaf mass fraction, and constructed costly, dense leaf and root tissues relative to colonizers. Likewise at maturity, beneficiaries had larger overall size and denser leaves coupled with greater water use efficiency than colonizers. In contrast to current hypotheses that suggest beneficiaries are less “stress-tolerant” than colonizers, beneficiaries exhibited conservative functional strategies suited to persistently dry, low light conditions beneath canopies, whereas colonizers exhibited opportunistic strategies that may be advantageous in fluctuating, open microenvironments. In addition, the signature of the regeneration niche at maturity indicates that facilitation expands the range of functional diversity within plant communities at all ontogenetic stages. This study demonstrates the utility of specific functional traits for predicting species’ regeneration niches in hot deserts, and provides a framework for studying facilitation in other severe environments. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1741-y) contains supplementary

  1. Thermal Regeneration of Sulfuric Acid Hydrates after Irradiation

    NASA Technical Reports Server (NTRS)

    Loeffler, Mark J.; Hudson, Reggie L.

    2012-01-01

    In an attempt to more completely understand the surface chemistry of the jovian icy satellites, we have investigated the effect of heating on two irradiated crystalline sulfuric acid hydrates, H2SO4 4H2O and H2SO4 H2O. At temperatures relevant to Europa and the warmer jovian satellites, post-irradiation heating recrystallized the amorphized samples and increased the intensities of the remaining hydrate's infrared absorptions. This thermal regeneration of the original hydrates was nearly 100% efficient, indicating that over geological times, thermally-induced phase transitions enhanced by temperature fluctuations will reform a large fraction of crystalline hydrated sulfuric acid that is destroyed by radiation processing. The work described is the first demonstration of the competition between radiation-induced amorphization and thermally-induced recrystallization in icy ionic solids relevant to the outer Solar System.

  2. Positive interactions between herbivores and plant diversity shape forest regeneration

    PubMed Central

    Cook-Patton, Susan C.; LaForgia, Marina; Parker, John D.

    2014-01-01

    The effects of herbivores and diversity on plant communities have been studied separately but rarely in combination. We conducted two concurrent experiments over 3 years to examine how tree seedling diversity, density and herbivory affected forest regeneration. One experiment factorially manipulated plant diversity (one versus 15 species) and the presence/absence of deer (Odocoileus virginianus). We found that mixtures outperformed monocultures only in the presence of deer. Selective browsing on competitive dominants and associational protection from less palatable species appear responsible for this herbivore-driven diversity effect. The other experiment manipulated monospecific plant density and found little evidence for negative density dependence. Combined, these experiments suggest that the higher performance in mixture was owing to the acquisition of positive interspecific interactions rather than the loss of negative intraspecific interactions. Overall, we emphasize that realistic predictions about the consequences of changing biodiversity will require a deeper understanding of the interaction between plant diversity and higher trophic levels. If we had manipulated only plant diversity, we would have missed an important positive interaction across trophic levels: diverse seedling communities better resist herbivores, and herbivores help to maintain seedling diversity. PMID:24718763

  3. Phenotypic and karyotypic status of Beta vulgaris plants regenerated from direct organogenesis in petiole culture.

    PubMed

    Detrez, C; Sangwan, R S; Sangwan-Norreel, B S

    1989-04-01

    A method for high frequency in vitro regeneration from petiole explants was tested on nine breeding lines of Beta vulgaris L. from the haploid, diploid and tetraploid levels. Regenerants could be obtained without a callus step, from excised petioles derived either from axillary buds sprouted in vitro or from field grown plants, by plating the explants on MS medium supplemented with TIBA (2,3,5-triiodobenzoïc acid) and BAP (6-Benzylaminopurine). The multiple shoots obtained were then rooted in vitro and transferred to soil. In some cases, these adventitious shoots were also used as a petiole explant source for further petiole culture cycles, and the phenotypic characteristics and ploidy status of the regenerants were investigated after one or three petiole culture cycles. Conventional shoot apex culture was used as an in vitro control. Phenotypic variations such as differences in morphology and changes in in vitro growth behaviour, were noticed. Chloroplast and chromosome counts indicated that the alterations in morphogenetic pathway could not be explained by the occurrence of gross cytogenetic abnormalities such as aneuploidy or myxoploidy. Our results suggest that the altered morphology is caused by the presence of the exogenous antiauxin (TIBA) during the in vitro phase. Following transfer to the greenhouse, none of these variations persisted and cytogenetic analyses revealed karyotypic stability in all the plants studied, even after three petiole culture cycles. An assessment of the in vitro petiole culture method as a true-to-type multiplication method for Beta vulgaris is made. PMID:24232710

  4. Retinoic acid in alveolar development, maintenance and regeneration.

    PubMed Central

    Maden, Malcolm; Hind, Matthew

    2004-01-01

    Recent data suggest that exogenous retinoic acid (RA), the biologically active derivative of vitamin A, can induce alveolar regeneration in a rat model of experimental emphysema. Here, we describe a mouse model of disrupted alveolar development using dexamethasone administered postnatally. We show that the effects of dexamethasone are concentration dependent, dose dependent, long lasting and result in a severe loss of alveolar surface area. When RA is administered to these animals as adults, lung architecture and the surface area per unit of body weight are completely restored to normal. This remarkable effect may be because RA is required during normal alveolar development and administering RA re-awakens gene cascades used during development. We provide evidence that RA is required during alveologenesis in the mouse by showing that the levels of the retinoid binding proteins, the RA receptors and two RA synthesizing enzymes peak postnatally. Furthermore, an inhibitor of RA synthesis, disulphiram, disrupts alveologenesis. We also show that RA is required throughout life for the maintenance of lung alveoli because when rats are deprived of dietary retinol they lose alveoli and show the features of emphysema. Alveolar regeneration with RA may therefore be an important novel therapeutic approach to the treatment of respiratory diseases characterized by a reduced gas-exchanging surface area such as bronchopulmonary dysplasia and emphysema for which there are currently no treatments. PMID:15293808

  5. Plant regeneration from organogenic callus and assessment of clonal fidelity in Elephantopus scaber Linn., an ethnomedicinal herb.

    PubMed

    Abraham, Jyothi; Thomas, T Dennis

    2015-04-01

    An efficient callus induction and plant regeneration system has been standardized for an ethnomedicinal plant, Elephantopus scaber Linn. Two explants i. e. seeds and leaf segments were used for callus induction. Murashige and Skoog (MS) medium supplemented with 5.0 μM 2, 4-dichlorophenoxy acetic acid (2, 4-D) and 0.5 μM kinetin (Kn) gave the optimum frequency (89 %) of callus induction from seed explant. The results showed that the highest response in terms of percent callus regenerating (91 %) and number of shoots (56) per culture was recorded on MS medium supplemented with 6.0 μM N6-benzylaminopurine (BA) and 1.5 μM α naphthalene acetic acid (NAA). The best rooting of regenerated shoots was obtained on half strength MS medium supplemented with 6.0 μM indole-3- butyric acid (IBA). On this medium, 100 % of the shoots produced roots with a mean number of 3.2 roots per shoot. The positive role of vesicular arbuscular mycorrhizae (VAM) along with potting mix has been well established in the present study. Of the various potting mix employed for plant acclimatization, the highest response of 100 % plant survival was noticed when autoclaved garden soil, sand (2:1) and VAM was utilized as potting mix. Inter-simple sequence repeats (ISSR) were used to establish the clonal fidelity of regenerated plantlets and the banding profiles from callus derived plants were monomorphic and similar to those of mother plant, thus ascertaining the true-to-type nature of these plants. PMID:25964719

  6. Microbiota and bile acid profiles in retinoic acid-primed mice that exhibit accelerated liver regeneration

    PubMed Central

    Liu, Hui-Xin; Hu, Ying; Wan, Yu-Jui Yvonne

    2016-01-01

    Background & Aims All-trans Retinoic acid (RA) regulates hepatic lipid and bile acid homeostasis. Similar to bile acid (BA), RA accelerates partial hepatectomy (PHx)-induced liver regeneration. Because there is a bidirectional regulatory relationship between gut microbiota and BA synthesis, we examined the effect of RA in altering the gut microbial population and BA composition and established their relationship with hepatic biological processes during the active phases of liver regeneration. Methods C57BL/6 mice were treated with RA orally followed by 2/3 PHx. The roles of RA in shifting gut microbiota and BA profiles as well as hepatocyte metabolism and proliferation were studied. Results RA-primed mice exhibited accelerated hepatocyte proliferation revealed by higher numbers of Ki67-positive cells compared to untreated mice. Firmicutes and Bacteroidetes phyla dominated the gut microbial community (>85%) in both control and RA-primed mice after PHx. RA reduced the ratio of Firmicutes to Bacteroidetes, which was associated with a lean phenotype. Consistently, RA-primed mice lacked transient lipid accumulation normally found in regenerating livers. In addition, RA altered BA homeostasis and shifted BA profiles by increasing the ratio of hydrophilic to hydrophobic BAs in regenerating livers. Accordingly, metabolic regulators fibroblast growth factor 21, Sirtuin1, and their downstream targets AMPK and ERK1/2 were more robustly activated in RA-primed than unprimed regenerating livers. Conclusions Priming mice with RA resulted in a lean microbiota composition and hydrophilic BA profiles, which were associated with facilitated metabolism and enhanced cell proliferation. PMID:26701854

  7. Plant regeneration via somatic embryogenesis and shoot organogenesis from immature cotyledons of Camellia nitidissima Chi.

    PubMed

    Lü, Jinfeng; Chen, Rong; Zhang, Muhan; da Silva, Jaime A Teixeira; Ma, Guohua

    2013-09-01

    Camellia nitidissima Chi (Theaceae) is a world-famous economic and ornamental plant with golden-yellow flowers. It has been classified as one of the rarest and most endangered plants in China. Our objective was to induce somatic embryogenesis, shoot organogenesis and plant regeneration for C. nitidissima. Three types of callus (whitish, reddish and yellowish) were induced from immature cotyledons on improved woody plant medium (WPM) with different plant growth regulators (PGRs). Among the callus, whitish callus was induced by 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and reddish and yellowish callus were induced by strongly active cytokinins, thidiazuron (TDZ) or 6-benzylaminopurine (BAP), singly or combined with weakly active auxin, α-naphthaleneacetic acid (NAA). The embryogenic callus could differentiate into somatic embryos, nodular embryogenic structures (large embryo-like structures) or adventitious shoots depending on the PGR used in WPM. BAP was best for adventitious buds and zeatin was best for somatic embryogenesis while kinetin (Kt) was best for the formation of nodular embryogenic structures. The three regeneration pathways often occurred in the same embryogenic callus clumps. Most shoots (80.0%) developed roots in WPM supplemented with 24.6 μM IBA and 0.3 μM NAA while 47.5% of somatic embryos could germinate directly and develop into plantlets on induction medium supplemented with 0.9 μM BAP and 0.1 μM NAA. The nodular embryogenic structures could be sub-cultured and cyclically developed in one of two differentiation pathways: shoot organogenesis or somatic embryogenesis. Plantlets derived from shoot buds rooted and somatic embryos germinated when transplanted into soil in a greenhouse; 66.7% of plantlets from shoot culture and 78.6% of plantlets from somatic embryos survived after 8 weeks' acclimatization. PMID:23790533

  8. Plant regeneration and ploidy variation in culture derived plants of Asclepias curassavica L.

    PubMed

    Pramanik, T K; Datta, S K

    1986-06-01

    Clonal propagation of medicinal milkweed, Asclepias curassavica L. (Asclepiadaceae) was achieved by culturing excised nodes on MS medium (Murashige and Skoog, 1962) supplemented with different hormone combinations. Both BAP and Kn were found equally effective for shoot initiation. IAA and NAA were found suitable for root induction. Combinations of Kn and NAA induced both roots and shoots after 30 days of culture. Chromosomal variation was observed in the roots of in vitro regenerated plants. Regenerants with higher chromosome number (33; 2n=22) obtained on MS medium in response to 9.2 μM Kn+10.7 μM NAA showed vigorous growth and higher propagation rates in culture than the plants possessing less than the diploid chromosome number (2n-2=20, 2n-4=18). Such variations are more likely due to genetic fitness of different aneuploids grown on a particular nutrient medium. PMID:24248138

  9. In vitro plant regeneration and genetic transformation of Dichanthium annulatum.

    PubMed

    Kumar, Jitendra; Shukla, Sharad M; Bhat, Vishnu; Gupta, Sanjay; Gupta, M G

    2005-11-01

    Optimization of in vitro plant regeneration and genetic transformation of apomictic species such as Dichanthium annulatum would enable transfer of desirable genes. Seven genotypes of this grass species were screened through mature seed explant for embryogenic callus induction, callus growth and quality (color and texture), and shoot induction. Genotype IG-1999, which produced highly embryogenic, rapidly growing good-quality callus capable of regenerating at a high frequency, was selected for transformation experiments. Using a binary vector (pCAMBIA1305), frequency of GUS expression was compared between two methods of transformation. Bombardment of embryogenic calli with gold particles coated with pCAMBIA1305 at a distance of 11 cm, pressure of 4 bars, and vacuum of 27 Hg passing through 100 muM mesh produced maximum GUS expression (23%). Agrobacterium infection was maximum at an optical density of 2.0 when cocultured under vacuum for 15 min and cocultivated for 3 days at 28 degrees C in constant dark on MS medium of pH 5.8 with 3 mg/l 2,4-D, and 400 muM acetosyringone. Among two binary vectors used for Agrobacterium-mediated transformation, pCAMBIA1301 showed higher frequency of GUS expression while pCAMBIA1305 recorded more of the GUS spots per callus. Supplementation of acetosyringone in the cocultivation medium was found indispensable for Agrobacterium-mediated transformation. Injuring the calli through gold particle bombardment before their cocultivation with Agrobacterium improved the transformation efficiency. Several transgenic plants were developed using the PIG method, while stable GUS-expressing calli were multiplied during selection on MS medium containing 250 mg/l cefotaxime and 50 mg/l hygromycin, incubated in constant dark. A highly significant difference was observed between two methods of transformation for both frequency of GUS expression and GUS spots per callus. PIG-mediated transformation resulted in higher GUS expression compared to the

  10. Pollination and seed dispersal are the most threatened processes of plant regeneration.

    PubMed

    Neuschulz, Eike Lena; Mueller, Thomas; Schleuning, Matthias; Böhning-Gaese, Katrin

    2016-01-01

    Plant regeneration is essential for maintaining forest biodiversity and ecosystem functioning, which are globally threatened by human disturbance. Here we present the first integrative meta-analysis on how forest disturbance affects multiple ecological processes of plant regeneration including pollination, seed dispersal, seed predation, recruitment and herbivory. We analysed 408 pairwise comparisons of these processes between near-natural and disturbed forests. Human impacts overall reduced plant regeneration. Importantly, only processes early in the regeneration cycle that often depend on plant-animal interactions, i.e. pollination and seed dispersal, were negatively affected. Later processes, i.e. seed predation, recruitment and herbivory, showed overall no significant response to human disturbance. Conserving pollination and seed dispersal, including the animals that provide these services to plants, should become a priority in forest conservation efforts globally. PMID:27435026

  11. Pollination and seed dispersal are the most threatened processes of plant regeneration

    PubMed Central

    Neuschulz, Eike Lena; Mueller, Thomas; Schleuning, Matthias; Böhning-Gaese, Katrin

    2016-01-01

    Plant regeneration is essential for maintaining forest biodiversity and ecosystem functioning, which are globally threatened by human disturbance. Here we present the first integrative meta-analysis on how forest disturbance affects multiple ecological processes of plant regeneration including pollination, seed dispersal, seed predation, recruitment and herbivory. We analysed 408 pairwise comparisons of these processes between near-natural and disturbed forests. Human impacts overall reduced plant regeneration. Importantly, only processes early in the regeneration cycle that often depend on plant-animal interactions, i.e. pollination and seed dispersal, were negatively affected. Later processes, i.e. seed predation, recruitment and herbivory, showed overall no significant response to human disturbance. Conserving pollination and seed dispersal, including the animals that provide these services to plants, should become a priority in forest conservation efforts globally. PMID:27435026

  12. Visualization of retinoic acid signaling in transgenic axolotls during limb development and regeneration

    PubMed Central

    Monaghan, James R.; Maden, Malcolm

    2012-01-01

    Retinoic acid (RA) plays a necessary role in limb development and regeneration, but the precise mechanism by which it acts during these processes is unclear. The role of RA in limb regeneration was first highlighted by the remarkable effect that it has on respecifying the proximodistal axis of the regenerating limb so that serially repeated limbs are produced. To facilitate the study of RA signaling during development and then during regeneration of the same structure we have turned to the axolotl, the master of vertebrate regeneration, and generated transgenic animals that fluorescently report RA signaling in vivo. Characterization of these animals identified an anterior segment of the developing embryo where RA signaling occurs revealing conserved features of the early vertebrate embryo. During limb development RA signaling was present in the developing forelimb bud mesenchyme, but was not detected during hindlimb development. During limb regeneration, RA signaling was surprisingly almost exclusively observed in the apical epithelium suggesting a different role of RA during limb regeneration. After the addition of supplemental RA to regenerating limbs that leads to pattern duplications, the fibroblast stem cells of the blastema responded showing that they are capable of transcriptionally responding to RA. These findings are significant because it means that RA signaling may play a multifunctional role during forelimb development and regeneration and that the fibroblast stem cells that regulate proximodistal limb patterning during regeneration are targets of RA signaling. PMID:22627291

  13. [Induction of polyploid in hairy roots of Nicotiana tabacum and its plant regeneration].

    PubMed

    Hou, Lili; Shi, Heping; Yu, Wu; Tsang, Po Keung Eric; Chow, Cheuk Fai Stephen

    2014-04-01

    By genetic transformation with Agrobacterum rhizogenes and artificial chromosome doubling techniques, we studied the induction of hairy roots and their polyploidization, and subsequent plant regeneration and nicotine determination to enhance the content of nicotine in Nicotiana tabacum. The results show that hairy roots could be induced from the basal surface of leaf explants of N. tabacum 8 days after inoculation with Agrobacterium rhizogenes ATCC15834. The percentage of the rooting leaf explants was 100% 15 days after inoculation. The hairy roots could grow rapidly and autonomously on solid or liquid phytohormones-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and paper electrophoresis of opines from N. tabacum hairy roots. The highest rate of polyploidy induction, more than 64.71%, was obtained after treatment of hairy roots with 0.1% colchicine for 36 h. The optimum medium for plant regeneration from polyploid hairy roots was MS+2.0 mg/L 6-BA +0.2 mg/L NAA. Compared with the control diploid plants, the hairy roots-regenerated plants had weak apical dominance, more axillary buds and more narrow leaves; whereas the polyploid hairy root-regenerated plants had thicker stems, shorter internodes and the colour, width and thickness of leaves were significantly higher than that of the control. Observation of the number of chromosomes in their root tip cells reveals that the obtained polyploid regenerated plants were tetraploidy, with 96 (4n = 96) chromosomes. Pot-grown experiments showed compared to the control, the flowering was delayed by 21 days in diploid hairy roots-regenerated plants and polyploid hairy root-regenerated plants. GC-MS detection shows that the content of nicotine in polyploid plants was about 6.90 and 4.57 times the control and the diploid hairy roots-regenerated plants, respectively. PMID:25195248

  14. [Protoplasts isolation, purification and plant regeneration of Pinellia cordata].

    PubMed

    Yang, Xian; Ma, Dan-Dan; Jiang, Fu-Sheng; Chen, Ni-Pi; Ding, Bin; Jin, Li-Xia; Qian, Chao-Dong; Ding, Zhi-Shan

    2014-11-01

    The main factors which affected the isolation, purification and cultivation of Pinellia cordata protoplasts from leaves were studied. The results indicated that the optimum enzyme solution for P. cordata leaves was 13% CPW + 1.0% Cellulose +0.1% Pectolase, at pH 6.0, temperature (25-28 degrees C ) for 4 h. The sucrose density gradient centrifugation was adopted to purificate the protoplasts collected, when 25% sucrose was used as mediator, centrifugating at 500 rpm for 10 min. When the protoplasts were shallow liquid and liquid-solid double layer cultured on the medium of MS + 0.5 mg x L(-1) 6-BA + 0.25 mg x L(-1) NAA + 13% mannitol at the density of 2.5 x 104 protoplasts/mL, or fed and nursed cultured at the density of 100-500 protoplasts/mL, cell division could be observed for 3 days; granular calli appeared for 30 days. Calli was proliferated on the medium of MS + 0.5 mg x L(-1) 6-BA + 0.25 mg x L(-1) NAA solidified by 0.55% agar, and differentiated and regenerated after 5-6 months. Plant generation of P. cordata is successfully established. PMID:25775795

  15. Chloroplast ultra structure, photosynthesis and enzyme activities in regenerated plants of Stevia rebaudiana (Bert.) Bertoni as influenced by copper sulphate in the medium.

    PubMed

    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. PMID:25241590

  16. Regeneration by somatic embryogenesis of triploid plants from endosperm of walnut, Juglans regia L. cv Manregian.

    PubMed

    Tulecke, W; McGranahan, G; Ahmadi, H

    1988-08-01

    Plants were regenerated by somatic embryogenesis from endosperm tissue of open-pollinated seeds of Juglans regia L. cv Manregian. These plants were obtained by growing endosperm tissue on media similar to those used for plant regeneration from walnut cotyledons (Tulecke and McGranahan 1985). The plants appear morphologically uniform and have a triploid chromosome number of 3n=48. Nine plants have been grown to a young sapling stage in soil. This embryogenic line from endosperm has been maintained in culture for two years by the process of repetitive somatic embryogenesis. PMID:24241869

  17. Localization of QTLs for in vitro plant regeneration in tomato

    PubMed Central

    2011-01-01

    Background Low regeneration ability limits biotechnological breeding approaches. The influence of genotype in the regeneration response is high in both tomato and other important crops. Despite the various studies that have been carried out on regeneration genetics, little is known about the key genes involved in this process. The aim of this study was to localize the genetic factors affecting regeneration in tomato. Results We developed two mapping populations (F2 and BC1) derived from a previously selected tomato cultivar (cv. Anl27) with low regeneration ability and a high regeneration accession of the wild species Solanum pennellii (PE-47). The phenotypic assay indicated dominance for bud induction and additive effects for both the percentage of explants with shoots and the number of regenerated shoots per explant. Two linkage maps were developed and six QTLs were identified on five chromosomes (1, 3, 4, 7 and 8) in the BC1 population by means of the Interval Mapping and restricted Multiple QTL Mapping methods. These QTLs came from S. pennellii, with the exception of the minor QTL located on chromosome 8, which was provided by cv. Anl27. The main QTLs correspond to those detected on chromosomes 1 and 7. In the F2 population, a QTL on chromosome 7 was identified on a similar region as that detected in the BC1 population. Marker segregation distortion was observed in this population in those areas where the QTLs of BC1 were detected. Furthermore, we located two tomato candidate genes using a marker linked to the high regeneration gene: Rg-2 (a putative allele of Rg-1) and LESK1, which encodes a serine/threonine kinase and was proposed as a marker for regeneration competence. As a result, we located a putative allele of Rg-2 in the QTL detected on chromosome 3 that we named Rg-3. LESK1, which is also situated on chromosome 3, is outside Rg-3. In a preliminary exploration of the detected QTL peaks, we found several genes that may be related to regeneration

  18. Nuclear receptor-dependent bile acid signaling is required for normal liver regeneration.

    PubMed

    Huang, Wendong; Ma, Ke; Zhang, Jun; Qatanani, Mohammed; Cuvillier, James; Liu, Jun; Dong, Bingning; Huang, Xiongfei; Moore, David D

    2006-04-14

    Liver mass depends on one or more unidentified humoral signals that drive regeneration when liver functional capacity is diminished. Bile acids are important liver products, and their levels are tightly regulated. Here, we identify a role for nuclear receptor-dependent bile acid signaling in normal liver regeneration. Elevated bile acid levels accelerate regeneration, and decreased levels inhibit liver regrowth, as does the absence of the primary nuclear bile acid receptor FXR. We propose that FXR activation by increased bile acid flux is a signal of decreased functional capacity of the liver. FXR, and possibly other nuclear receptors, may promote homeostasis not only by regulating expression of appropriate metabolic target genes but also by driving homeotrophic liver growth. PMID:16614213

  19. Very-long-chain fatty acids restrict regeneration capacity by confining pericycle competence for callus formation in Arabidopsis.

    PubMed

    Shang, Baoshuan; Xu, Chongyi; Zhang, Xixi; Cao, Huifen; Xin, Wei; Hu, Yuxin

    2016-05-01

    The already differentiated organs in plants have a remarkable capacity to regenerate new individuals under culture conditions. Plant in vitro regeneration practically starts with the induction of a pluripotent cell mass, the callus, from detached organs on auxin-rich callus-inducing medium (CIM), which is generally required for subsequent regeneration of new bodies. Recent studies show that CIM-induced callus formation occurs from the pericycle or pericycle-like cells through a root developmental pathway, whereas the signals involved in governing callus-forming capacity of pericycle cells remain unknown. Here we report that very-long-chain fatty acids (VLCFAs) play a critical role in confining the pericycle competence for callus formation and thus the regeneration capacity of Arabidopsis By genetic screening, we identified the callus formation-related 1 (cfr1) mutant, which bypasses the inhibition of callus-forming capacity in roots by solitary-root (slr/iaa14). We show that CFR1 encodes 3-ketoacyl-CoA synthase 1 (KCS1), which catalyzes a rate-limiting step of VLCFA biosynthesis. Our biochemical and genetic analyses demonstrate that VLCFAs restrict the pericycle competence for callus formation, at least in part, by regulating the transcription of Aberrant Lateral Root Formation 4 (ALF4). Moreover, we provide evidence that VLCFAs act as cell layer signals to mediate the pericycle competence for callus formation. Taken together, our results identify VLCFAs or their derivatives as the confining signals for mediating the pericycle competence for callus formation and thus the regeneration capacity of plant organs. PMID:27092001

  20. Retinoic acid receptor beta2 promotes functional regeneration of sensory axons in the spinal cord.

    PubMed

    Wong, Liang-Fong; Yip, Ping K; Battaglia, Anna; Grist, John; Corcoran, Jonathan; Maden, Malcolm; Azzouz, Mimoun; Kingsman, Susan M; Kingsman, Alan J; Mazarakis, Nicholas D; McMahon, Stephen B

    2006-02-01

    The embryonic CNS readily undergoes regeneration, unlike the adult CNS, which has limited axonal repair after injury. Here we tested the hypothesis that retinoic acid receptor beta2 (RARbeta2), critical in development for neuronal growth, may enable adult neurons to grow in an inhibitory environment. Overexpression of RARbeta2 in adult rat dorsal root ganglion cultures increased intracellular levels of cyclic AMP and stimulated neurite outgrowth. Stable RARbeta2 expression in DRG neurons in vitro and in vivo enabled their axons to regenerate across the inhibitory dorsal root entry zone and project into the gray matter of the spinal cord. The regenerated neurons enhanced second-order neuronal activity in the spinal cord, and RARbeta2-treated rats showed highly significant improvement in sensorimotor tasks. These findings show that RARbeta2 induces axonal regeneration programs within injured neurons and may thus offer new therapeutic opportunities for CNS regeneration. PMID:16388307

  1. Somatic embryogenesis pathway for plant regeneration in Qinjiao (Gentiana macrophylla Pall.).

    PubMed

    Chen, Li Yu; Xu, Zi Qin

    2007-08-01

    Qinjiao (Gentiana macrophylla Pall.) is a perennial herbage native to northwestern China. It has been taken as a kind of Chinese herbs for more than one thousand years. The major secondary metabolite named as gentiopicroside accounts for 8% of the dry weight of roots. It has been used for medical purpose in the treatment with rheumatism, osteoarthritis, inflammatory or ulceration. Conventionally, Qinjiao is propagated by seeds, but the seeds should be planted in one year after harvesting and the germination rate is extremely low. These confine its spread by seeds after year-round storage. Therefore, plant regeneration from somatic cells will be an ideal way for its propagation. Plant regeneration from somatic cell can be divided into two ways: somatic embryogenesis and organogenesis. Similar to zygotic embryo, somatic embryo has a bipolar structure with both shoot and root poles. Somatic embryogenesis also goes through the same key stages as globular-, heart-, torpedo- and cotyledon-stages Somatic embryogenesis was first observed in carrot callus cells more than 45 years ago. Since then, plant regeneration via somatic embryogenesis has been studied in many important species. Though the plant regeneration of Qinjiao has been previously studied, there is no investigation of somatic embryogenesis reported in this plant. Therefore, the aim of our experiment is to confirm the somatic embryogenesis pathway of plant regeneration in Qinjiao. PMID:17966465

  2. Gynogenic plant regeneration from unpollinated flower explants of Eragrostis tef (Zuccagni) Trotter.

    PubMed

    Gugsa, Likyelesh; Sarial, Ashok K; Lörz, Horst; Kumlehn, Jochen

    2006-12-01

    Tef [Eragrostis tef (Zucc.) Trotter] is the most important cereal in Ethiopia. In its wild relative E. mexicana, regeneration of six green plants resulted from culture of 121 non-pollinated immature pistils. In the allotetraploid crop species tef, however, only callus and root formation was obtained by this method. By contrast, immature spikelets and panicle segments of E. tef proved amenable to gynogenic plant regeneration. Upon step-wise optimization of the protocol, efficient plant formation was achieved in all three cultivars tested. In cv. DZ-01-196, culture of 1305 immature spikelets resulted in formation of 159 green plants. Flow cytometric analysis revealed (di)haploid, triploid, tetraploid and octoploid regenerants, from which the vast majority was tetraploid. Tef-breeding programs will likely benefit substantially from efficient generation of true-breeding plants. PMID:16832620

  3. Farnesoid X receptor, the bile acid sensing nuclear receptor, in liver regeneration

    PubMed Central

    Li, Guodong; L. Guo, Grace

    2015-01-01

    The liver is unique in regenerative potential, which could recover the lost mass and function after injury from ischemia and resection. The underlying molecular mechanisms of liver regeneration have been extensively studied in the past using the partial hepatectomy (PH) model in rodents, where 2/3 PH is carried out by removing two lobes. The whole process of liver regeneration is complicated, orchestrated event involving a network of connected interactions, which still remain fully elusive. Bile acids (BAs) are ligands of farnesoid X receptor (FXR), a nuclear receptor of ligand-activated transcription factor. FXR has been shown to be highly involved in liver regeneration. BAs and FXR not only interact with each other but also regulate various downstream targets independently during liver regeneration. Moreover, recent findings suggest that tissue-specific FXR also contributes to liver regeneration significantly. These novel findings suggest that FXR has much broader role than regulating BA, cholesterol, lipid and glucose metabolism. Therefore, these researches highlight FXR as an important pharmaceutical target for potential use of FXR ligands to regulate liver regeneration in clinic. This review focuses on the roles of BAs and FXR in liver regeneration and the current underlying molecular mechanisms which contribute to liver regeneration. PMID:26579433

  4. High frequency shoots regeneration for mass multiplication of Phyllanthus fraternus Webster--an important antiviral and hepatoprotective plant.

    PubMed

    Upadhyay, Richa; Tiwari, Kavindra Nath; Singh, Karuna

    2013-04-01

    An efficient, rapid, and highly reproducible regeneration protocol was successfully developed for Phyllanthus fraternus from the field-derived mature nodal segments. The explants induced multiple shoots on cytokinin containing medium. The highest frequency (99 %) and maximum number of shoots (19.75) were induced on Murashige and Skoog's (MS) medium supplemented with 2.22 μM 6-benzylaminopurine after 3-4 weeks of culture initiation. The elongated shoots were rooted on MS medium supplemented with indol-3-butyric acid (IBA) or α-naphthalene acetic acid. Pulse treatment of microshoots promoted significant increase in the percentage of rooting and number of root regeneration per shoot. The highest rooting (100 %) and maximum number of roots (8.75) per shoot was obtained when shoots were dipped in IBA solution (0.98 mM) for 5 min and further subcultured on MS basal medium. Plantlets were successfully acclimatized and established in soil. Regenerated plants were grown normally in the field without showing any morphological variations. This cost-effective protocol will help the mass multiplication of P. fraternus for commercial propagation and high biomass production of this valuable medicinal plant. PMID:23446983

  5. Light Inhibition of Shoot Regeneration Is Regulated by Endogenous Abscisic Acid Level in Calli Derived from Immature Barley Embryos.

    PubMed

    Rikiishi, Kazuhide; Matsuura, Takakazu; Ikeda, Yoko; Maekawa, Masahiko

    2015-01-01

    Shoot regeneration in calli derived from immature barley embryos is regulated by light conditions during the callus-induction period. Barley cultivars Kanto Nijo-5 (KN5) and K-3 (K3) showed lower efficiency of shoot regeneration in a 16-h photoperiod during callus-induction than those in continuous darkness, whereas shoot regeneration was enhanced in cultures under a 16-h photoperiod in Golden Promise (GP) and Lenins (LN). These cultivars were classified as photo-inhibition type (KN5 and K3) or photo-induction type (GP and LN) according to their response to light. Contents of endogenous plant hormones were determined in calli cultured under a 16-h photoperiod and continuous darkness. In photo-inhibition type, higher accumulation of abscisic acid (ABA) was detected in calli cultured under a 16-h photoperiod, whereas calli showed lower levels of endogenous ABA in continuous darkness. However, cultivars of photo-induction type showed lower levels of ABA in calli cultured under both light conditions, similarly to photo-inhibition type in continuous darkness. Exogenous ABA inhibited the callus growth and shoot regeneration independent of light conditions in all cultivars. In photo-inhibition type, lower levels of endogenous ABA induced by ABA biosynthesis inhibitor, fluridone, reduced the photo-inhibition of shoot regeneration. Expression of ABA biosynthesis gene, HvNCED1, in calli was regulated by the light conditions. Higher expression was observed in calli cultured under a 16-h photoperiod. These results indicate that ABA biosynthesis could be activated through the higher expression of HvNCED1 in a 16-h photoperiod and that the higher accumulations of ABA inhibit shoot regeneration in the photo-inhibition type cultivars. PMID:26670930

  6. Light Inhibition of Shoot Regeneration Is Regulated by Endogenous Abscisic Acid Level in Calli Derived from Immature Barley Embryos

    PubMed Central

    Rikiishi, Kazuhide; Matsuura, Takakazu; Ikeda, Yoko; Maekawa, Masahiko

    2015-01-01

    Shoot regeneration in calli derived from immature barley embryos is regulated by light conditions during the callus-induction period. Barley cultivars Kanto Nijo-5 (KN5) and K-3 (K3) showed lower efficiency of shoot regeneration in a 16-h photoperiod during callus-induction than those in continuous darkness, whereas shoot regeneration was enhanced in cultures under a 16-h photoperiod in Golden Promise (GP) and Lenins (LN). These cultivars were classified as photo-inhibition type (KN5 and K3) or photo-induction type (GP and LN) according to their response to light. Contents of endogenous plant hormones were determined in calli cultured under a 16-h photoperiod and continuous darkness. In photo-inhibition type, higher accumulation of abscisic acid (ABA) was detected in calli cultured under a 16-h photoperiod, whereas calli showed lower levels of endogenous ABA in continuous darkness. However, cultivars of photo-induction type showed lower levels of ABA in calli cultured under both light conditions, similarly to photo-inhibition type in continuous darkness. Exogenous ABA inhibited the callus growth and shoot regeneration independent of light conditions in all cultivars. In photo-inhibition type, lower levels of endogenous ABA induced by ABA biosynthesis inhibitor, fluridone, reduced the photo-inhibition of shoot regeneration. Expression of ABA biosynthesis gene, HvNCED1, in calli was regulated by the light conditions. Higher expression was observed in calli cultured under a 16-h photoperiod. These results indicate that ABA biosynthesis could be activated through the higher expression of HvNCED1 in a 16-h photoperiod and that the higher accumulations of ABA inhibit shoot regeneration in the photo-inhibition type cultivars. PMID:26670930

  7. Closed cycle ion exchange method for regenerating acids, bases and salts

    DOEpatents

    Dreyfuss, Robert M.

    1976-01-01

    A method for conducting a chemical reaction in acidic, basic, or neutral solution as required and then regenerating the acid, base, or salt by means of ion exchange in a closed cycle reaction sequence which comprises contacting the spent acid, base, or salt with an ion exchanger, preferably a synthetic organic ion-exchange resin, so selected that the counter ions thereof are ions also produced as a by-product in the closed reaction cycle, and then regenerating the spent ion exchanger by contact with the by-product counter ions. The method is particularly applicable to closed cycle processes for the thermochemical production of hydrogen.

  8. Red spruce germination and growth in soil-mediated regeneration microcosms under acid precipitation

    SciTech Connect

    Ho, M.

    1992-01-01

    In the past three decades, atmospheric pollution has caused substantial problems for the environment as well as for many biological processes. The objective of this study focuses on red spruce (Picea ruben Sarg.) regeneration potential and chemical change within the soil-water-plant continuum following simulated acid rain treatments. Inceptisols from three forests at 1735, 1920, and 2015 m at Mt. Mitchell, North Carolina had lower pH, bulk density, and higher organic matter, and base cations as altitude increased. Red spruce seeds were collected from two nearby standing trees at the 1735 m site. A strip-split-split plot experiment was constructed using soils from the two lower elevations, which support natural red spruce stands. Besides a control (pH 5.6, NO[sub 3]:SO[sub 4] ratio 0.10), eight treatments corresponding to two pHs (3.5 and 4.2) with four NO[sub 3]:SO[sub 4] ratios (0.20, 0.33, 0.40, and 0.67) each were used. Seedling emergence and growth, chemistry of soil. Soil leachate, and plant tissue were analyzed to test soil differences and treatment effects of acidity, nitrate, and sulfate. Temporal patterns of germination respond more to soil than to rain chemistry, but significant interactions were found. Besides higher survival, faster germinating seedlings in the 1735 m soil also produced more complex root system and more biomass. Lower root-to-shoot ratios at more acidic treatments suggest a negative effect of acidity on root growth. Canonical discriminant analysis revealed that factors controlling overall soil chemistry were dominated by soil origin, then by rain pH.

  9. Studies on plant regeneration and somaclonal variation in Saintpaulia ionantha Wendl. (African violet).

    PubMed

    Daud, Norhayati; Taha, Rosna Mat; Hasbullah, Nor Azlina

    2008-05-01

    Efficient plant regeneration of Saintpaulia ionantha (African violet) has been obtained in the present study. MS medium supplemented with 1.0 mg L(-1) IAA and 2.0 mg L(-1) Zeatin resulted in 100% shoot regeneration and induced the highest number of shoots (average 15.0 +/- 0.8 shoots per explant) after being cultured for 8 weeks. The above hormone combination was optimum for shoot regeneration. Most of Saintpaulia ionantha plantlets derived from tissue culture system could be hardened and transferred to the greenhouse conditions with 84.0 +/- 1.6% success rate. However, regenerated plantlets of Saintpaulia ionantha (even after 12-months-old) failed to flower. Morphological characters of regenerated plantlets of Saintpaulia ionantha were observed and compared with in vivo (intact) plants. Regenerated plantlets showed some differences in morphological characters, such as height and leaf size, texture and colour, but the plantlets showed no variation in leaf arrangement and leaf margin. However, the morphological characters of the regenerated plantlets were found to be unstable. PMID:18819532

  10. TRANEXAMIC ACID ACTION ON LIVER REGENERATION AFTER PARTIAL HEPATECTOMY: EXPERIMENTAL MODEL IN RATS

    PubMed Central

    SOBRAL, Felipe Antonio; DAGA, Henrique; RASERA, Henrique Nogueira; PINHEIRO, Matheus da Rocha; CELLA, Igor Furlan; MORAIS, Igor Henrique; MARQUES, Luciana de Oliveira; COLLAÇO, Luiz Martins

    2016-01-01

    ABSTRACT Background: Different lesions may affect the liver resulting in harmful stimuli. Some therapeutic procedures to treat those injuries depend on liver regeneration to increase functional capacity of this organ. Aim: Evaluate the effects of tranexamic acid on liver regeneration after partial hepatectomy in rats. Method: 40 rats (Rattus norvegicus albinus, Rodentia mammalia) of Wistar-UP lineage were randomly divided into two groups named control (CT) and tranexamic acid (ATX), with 20 rats in each. Both groups were subdivided, according to liver regeneration time of 32 h or seven days after the rats had been operated. The organ regeneration was evaluated through weight and histology, stained with HE and PCNA. Results: The average animal weight of ATX and CT 7 days groups before surgery were 411.2 g and 432.7 g, and 371.3 g and 392.9 g after the regeneration time, respectively. The average number of mitotic cells stained with HE for the ATX and CT 7 days groups were 33.7 and 32.6 mitosis, and 14.5 and 14.9 for the ATX and CT 32 h groups, respectively. When stained with proliferating cell nuclear antigen, the numbers of mitotic cells counted were 849.7 for the ATX 7 days, 301.8 for the CT 7 days groups, 814.2 for the ATX 32 hand 848.1 for the CT 32 h groups. Conclusion: Tranexamic acid was effective in liver regeneration, but in longer period after partial hepatectomy.

  11. Bile acid promotes liver regeneration via farnesoid X receptor signaling pathways in rats.

    PubMed

    Ding, Long; Yang, Yu; Qu, Yikun; Yang, Ting; Wang, Kaifeng; Liu, Weixin; Xia, Weibin

    2015-06-01

    Bile acids, which are synthesized from cholesterol in the hepatocytes of the liver, are amphipathic molecules with a steroid backbone. Studies have shown that bile acid exhibits important effects on liver regeneration. However, the mechanism underlying these effects remains unclear. The aim of the present study was to investigate the effect of bile acid and the farnesoid X receptor (FXR) on hepatic regeneration and lipid metabolism. Rats were fed with 0.2% bile acid or glucose for 7 days and then subjected to a 50 or 70% hepatectomy. Hepatic regeneration rate, serum and liver levels of bile acid, and expression of FXR and Caveolin‑1, were detected at 24, 48 or 72 h following hepatectomy. The expression of proliferating cell nuclear antigen (PCNA) in the liver was measured using immunohistochemistry at the end of the study. Hepatocytes isolated from rats were treated with bile acid, glucose, FXR agonist and FXR antagonist, separately or in combination. Lipid metabolism, the expression of members of the FXR signaling pathway and energy metabolism‑related factors were measured using ELISA kits or western blotting. Bile acid significantly increased the hepatic regeneration rate and the expression of FXR, Caveolin‑1 and PCNA. Levels of total cholesterol and high density lipoprotein were increased in bile acid‑ or FXR agonist‑treated hepatocytes in vitro. Levels of triglyceride, low density lipoprotein and free fatty acid were decreased. In addition, bile acid and FXR agonists increased the expression of bile salt export pump and small heterodimer partner, and downregulated the expression of apical sodium‑dependent bile acid transporter, Na+/taurocholate cotransporting polypeptide and cholesterol 7α‑hydroxylase. These results suggested that physiological concentrations of bile acid may promote liver regeneration via FXR signaling pathways, and may be associated with energy metabolism. PMID:25634785

  12. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

    SciTech Connect

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  13. AMMONIA ABSORPTION/AMMONIUM BISULFATE REGENERATION PILOT PLANT FOR FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The report gives results of a pilot-plant study of the ammonia absorption/ammonium bisulfate regeneration process for removing SO2 from the stack gas of coal-fired power plants. Data were developed on the effects of such operating variable in the absorption of SO2 by ammoniacal l...

  14. Somatic embryogenesis and plant regeneration of cassava (Manihot esculenta Crantz) landraces from Cameroon.

    PubMed

    Mongomake, Kone; Doungous, Oumar; Khatabi, Behnam; Fondong, Vincent N

    2015-01-01

    A procedure to regenerate cassava (Manihot esculenta Crantz) cultivars from Cameroon via somatic embryogenesis (SE) was developed. Shoot apical meristems and immature leaf lobes were used as explants on Murashige and Skoog (MS) basal medium containing 33 or 50 µM of the auxins Picloram (Pic), 2,4-Dichlorophenoxyacetic acid (2,4-D), Dicamba (Dic), and α-Naphthalene acetic acid. Cultivar performance was assessed using SE and number of somatic embryos produced. Overall, the frequency of primary somatic embryogenesis (PSE) and the mean number of somatic embryos produced varied considerably with genotype, type of auxin and concentration tested. For example, cultivar (cv.) Ngan Mbada showed the best performance on MS medium supplemented with 50 µM Pic with a SE frequency of 40 % and an average number of somatic embryos of 90. The second best performance was recorded in cv. Local Red on MS medium supplemented with 33 µM 2,4-D, where the SE frequency was 40 % and an average number of somatic embryos of 60.5. Cultivar Ekona Red recorded the best performance on medium supplemented with 50 µM Pic showing a SE frequency of 47 % and an average number of somatic embryos of 45. We further examined secondary and cyclic somatic embryogenesis (SSE, CSE) and both were also observed to vary with genotype, however, both exhibited significantly higher frequencies of SE compared with PSE. SE started to decline at the fourth cycle of embryogenesis. Examination of organogenesis showed that shoot bud induction from green cotyledons varied across cultivars and benzylaminopurine was shown to outperform Thidiazuron in the ability to induce organogenesis. Furthermore, the frequencies of bud induction were identical under light and dark conditions. Finally, regenerated plants grew easily in the greenhouse with 90-100 % survival rate and did not display detectable variation in morphology. PMID:26361578

  15. Regeneration of Acid Orange 7 Exhausted Granular Activated Carbon Using Pulsed Discharge Plasmas

    NASA Astrophysics Data System (ADS)

    Wang, Huijuan; Guo, He; Liu, Yongjie; Yi, Chengwu

    2015-10-01

    In this paper, a pulsed discharge plasma (PDP) system with a multi-needle-to-plate electrodes geometry was set up to investigate the regeneration of acid orange 7 (AO7) exhausted granular activated carbon (GAC). Regeneration of GAC was studied under different conditions of peak pulse discharge voltage and water pH, as well as the modification effect of GAC by the pulse discharge process, to figure out the regeneration efficiency and the change of the GAC structure by the PDP treatment. The obtained results showed that there was an appropriate peak pulse voltage and an optimal initial pH value of the solution for GAC regeneration. Analyses of scanning electron microscope (SEM), Boehm titration, Brunauer-Emmett-Teller (BET), Horvath-Kawazoe (HK), and X-ray Diffraction (XRD) showed that there were more mesopore and macropore in the regenerated GAC and the structure turned smoother with the increase of discharge voltage; the amount of acidic functional groups on the GAC surface increased while the amount of basic functional groups decreased after the regeneration process. From the result of the XRD analysis, there were no new substances produced on the GAC after PDP treatment. supported by National Natural Science Foundation of China (No. 21207052), China Postdoctoral Science Foundation (No. 20110491353) and Jiangsu Planned Projects for Postdoctoral Research Funds, China (No. 1102116C)

  16. Regeneration of flax ( Linum usitatissimum L.) plants from anther culture and somatic tissue with increased resistance to Fusarium oxysporum.

    PubMed

    Rutkowska-Krause, I; Mankowska, G; Lukaszewicz, M; Szopa, J

    2003-09-01

    The aim of this study was to establish a protocol for the efficient production of flax plants of microspore origin. The results were compared to those obtained for plants regenerated from somatic explants from hypocotyls, cotyledons, leaves, stems and roots. All the plants obtained during the experiments were regenerated from callus that was grown for periods from a few weeks to a few months before the regeneration was achieved. Anther cultures were less effective in plant regeneration than somatic cell cultures. However, regenerants derived from anther cells showed valuable breeding features, including increased resistance to fungal wilt. The age of the donor plants and the season they grew in had a noticeable effect on their anther callusing and subsequent plant regeneration. Low temperature had a negative effect and dark pre-treatment a positive effect on callusing and plant regeneration. Different media were most effective for callus induction, shoot induction and rooting. For callus induction two carbon sources (2.5% sucrose and 2.5% glucose) were most effective; for shoots, only sucrose at lower concentration (2%) was effective. Rooting was most efficient in 1% sucrose and reduced (50%) mineral concentration in the medium. It was found that the length of in vitro cultivation significantly increases the ploidy and affects such features as regenerant morphological characteristics, petal colour, and resistance to Fusarium oxysporum-induced fungal wilt. The established plant regeneration system provides a basis for the creation of transgenic flax. PMID:12827441

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

    DOEpatents

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

    2001-01-01

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

  18. Injectable oxidized hyaluronic acid/adipic acid dihydrazide hydrogel for nucleus pulposus regeneration.

    PubMed

    Su, Wen-Yu; Chen, Yu-Chun; Lin, Feng-Huei

    2010-08-01

    Injectable hydrogel allows irregular surgical defects to be completely filled, lessens the risk of implant migration, and minimizes surgical defects due to the solution-gel state transformation. Here, we first propose a method for preparing oxidized hyaluronic acid/adipic acid dihydrazide (oxi-HA/ADH) injectable hydrogel by chemical cross-linking under physiological conditions. Fourier transform infrared spectrometry and trinitrobenzene sulfonate assay were used to confirm the oxidation of hyaluronic acid. Rheological properties were measured to evaluate the working ability of the hydrogel for further clinical application. The oxi-HA/ADH in situ forming hydrogel can transform from liquid form into a gel-like matrix within 3-8 min, depending on the operational temperature. Furthermore, hydrogel degradation and cell assessment is also a concern for clinical application. Injectable oxi-HA/ADH8 hydrogel can maintain its gel-like state for at least 5 weeks with a degradation percentage of 40%. Importantly, oxi-HA/ADH8 hydrogel can assist in nucleus pulposus cell synthesis of type II collagen and aggrecan mRNA gene expression according to the results of real-time PCR analysis, and shows good biocompatibility based on cell viability and cytotoxicity assays. Based on the results of the current study, oxi-HA/ADH hydrogel may possess several advantages for future application in nucleus pulposus regeneration. PMID:20193782

  19. [Induction of polyploid hairy roots and its plant regeneration in Pogostemon cablin].

    PubMed

    Shi, Heping; Yu, Wu; Zhang, Guopeng; Tsang, Pokeung Eric; Chow, Cheuk Fai Stephen

    2014-08-01

    Abstract: In order to enhance the content of secondary metabolites patchouli alcohol in Pogostemon cablin, we induced polyploid hairy roots and their plant regeneration, and determined the content of patchouli alcohol through artificial chromosome doubling with colchicine. The highest rate of polyploidy induction was more than 40% when hairy roots were treated with 0.05% colchicine for 36 h. The obtained polyploid hairy roots formed adventitious shoots when cultured in an MS medium with 6-BA 0.2 mg/L and NAA 0.1 mg/L for 60 d. Compared with the control diploid plants, the polyploid hairy root-regenerated plants of P. cablin had more developed root systems, thicker stems, shorter internodes and longer, wider and thicker leaves. Observation of the chromosome number in their root tip cells reveals that the obtained polyploid regenerated plants were tetraploidy, with 128 (4n = 128) chromosomes. The leaves contained around twice as many stomatal guard cells and chloroplasts as the controls, but the stomatal density declined with increasing ploidy. The stomatal density in diploid plants was around 1.67 times of that in polyploid plants. GC-MS analysis shows that the content of patchouli alcholol in the hairy root-derived polyploid plants was about 4.25 mg/g dry weight, which was 2.3 times of that in diploid plants. The present study demonstrates that polyploidization of hairy roots can stimulate the content of patchouli alcholol in medicinal plant of P. cablin. PMID:25507476

  20. [Induction of polyploid hairy roots and its plant regeneration in Pogostemon cablin].

    PubMed

    Shi, Heping; Yu, Wu; Zhang, Guopeng; Tsang, Pokeung Eric; Chow, Cheuk Fai Stephen

    2014-08-01

    Abstract: In order to enhance the content of secondary metabolites patchouli alcohol in Pogostemon cablin, we induced polyploid hairy roots and their plant regeneration, and determined the content of patchouli alcohol through artificial chromosome doubling with colchicine. The highest rate of polyploidy induction was more than 40% when hairy roots were treated with 0.05% colchicine for 36 h. The obtained polyploid hairy roots formed adventitious shoots when cultured in an MS medium with 6-BA 0.2 mg/L and NAA 0.1 mg/L for 60 d. Compared with the control diploid plants, the polyploid hairy root-regenerated plants of P. cablin had more developed root systems, thicker stems, shorter internodes and longer, wider and thicker leaves. Observation of the chromosome number in their root tip cells reveals that the obtained polyploid regenerated plants were tetraploidy, with 128 (4n = 128) chromosomes. The leaves contained around twice as many stomatal guard cells and chloroplasts as the controls, but the stomatal density declined with increasing ploidy. The stomatal density in diploid plants was around 1.67 times of that in polyploid plants. GC-MS analysis shows that the content of patchouli alcholol in the hairy root-derived polyploid plants was about 4.25 mg/g dry weight, which was 2.3 times of that in diploid plants. The present study demonstrates that polyploidization of hairy roots can stimulate the content of patchouli alcholol in medicinal plant of P. cablin. PMID:25423753

  1. Retinoic acid signaling spatially restricts osteoblasts and controls ray-interray organization during zebrafish fin regeneration.

    PubMed

    Blum, Nicola; Begemann, Gerrit

    2015-09-01

    The zebrafish caudal fin consists of repeated units of bony rays separated by soft interray tissue, an organization that must be faithfully re-established during fin regeneration. How and why regenerating rays respect ray-interray boundaries, thus extending only the existing bone, has remained unresolved. Here, we demonstrate that a retinoic acid (RA)-degrading niche is established by Cyp26a1 in the proximal basal epidermal layer that orchestrates ray-interray organization by spatially restricting osteoblasts. Disruption of this niche causes preosteoblasts to ignore ray-interray boundaries and to invade neighboring interrays where they form ectopic bone. Concomitantly, non-osteoblastic blastema cells and regenerating blood vessels spread into the interrays, resulting in overall disruption of ray-interray organization and irreversible inhibition of fin regeneration. The cyp26a1-expressing niche plays another important role during subsequent regenerative outgrowth, where it facilitates the Shha-promoted proliferation of osteoblasts. Finally, we show that the previously observed distal shift of ray bifurcations in regenerating fins upon RA treatment or amputation close to the bifurcation can be explained by inappropriate preosteoblast alignment and does not necessarily require putative changes in proximodistal information. Our findings uncover a mechanism regulating preosteoblast alignment and maintenance of ray-interray boundaries during fin regeneration. PMID:26253402

  2. Plant regeneration through somatic embryogenesis from callus induced on immature embryos of Alstroemeria spp. L.

    PubMed

    Van Schaik, C E; Posthuma, A; De Jeu, M J; Jacobsen, E

    1996-01-01

    The plant regeneration ability of callus obtained from zygotic embryos of the monocot Alstroemeria spp. was studied. The best explants for somatic embryogenesis were immature zygotic embryos in half-ovules when the endosperm was still soft and white. For 2 genotypes embryogenic callus was induced on callus induction medium with a success rate of 54%. The best callus induction period was 10 weeks. The morphology of embryogenic callus was nodular. Somatic embryos were formed after transfer of the callus to regeneration medium. These somatic embryos revealed later on the typical features of zygotic Alstroemeria embryos. The total duration of the plant regeneration protocol, from inoculation till rooted plantlets ready for transfer to the greenhouse, was 28 weeks. PMID:24178361

  3. High efficiency plant regeneration from petiole explants of Carica papaya L. through organogenesis.

    PubMed

    Hossain, M; Rahman, S M; Islam, R; Joarder, O I

    1993-12-01

    Callus cultures were obrained from petiole explants of Carica papaya on MS medium containing 0.5-10.5 μM α-naphthaleneacetic acid (NAA) in combination with 0.5-5 μM benzyladenine (BA). Hard-green calli were transferred to MS medium containing 100 mgl(-1) casein hydrolysate (CH) with specific BA-NAA formulation, where they developed adventitious buds within 2 weeks of culture. Maximum number of adventitious buds were obtained in 2 μM BA and 0.1 μM NAA. Shoot regeneration occurred from these adventitious buds by the end of the 4th week. Regenerated shoots were elongated in hormone-free medium and rooted in half-strength MS fortified with 3 UM NAA and 0.5 μM gibberellic acid (GA3). The regenerants were transferred to soil after acclimatization. PMID:24196296

  4. Effect of exogenous indole-3-acetic acid and naphthalene acetic acid on regeneration of damask rose cuttings in three growing media.

    PubMed

    Khan, Rahmat Ullah; Khan, Muhammad Sohail; Rashid, Abdur; Farooq, Arshad

    2007-10-15

    An experiment was conducted to evaluate the performance of various levels of indole-3-acetic acid (IAA) and naphthalene acetic acid (NAA) treatments i.e., 0, 25, 50, 75, 100 mg L(-1) on the regeneration of damask rose (Rosa damascena Mill.) cuttings in different growing media at the research farm of Arid Zone Research Institute D.I. Khan during 2004. The data revealed significant effect of different levels of growth regulators and growing media on the rose establishment parameters viz., plant height, plant spread, number of primary shoots, secondary shoots and survival percentage. Maximum plant height (134.2 cm), plant spread (46.3 cm), primary shoots (6.3), secondary shoots (25) and survival percentage (94.72%) were recorded when the rose cuttings were applied with NAA at the rate of 50 mg L(-1). Among the plant growth regulators, Naphthalene Acetic Acid (NAA) was found to be superior to indole-3-acetic acid (IAA) for its stronger effect regarding all parameters. The optimum level of Naphthalene Acetic Acid (NAA) was found in the range of 50 and 75 mg L(-1), while no such conclusion could be drawn for indole-3-acetic acid (IAA) as all growth parameters were linearly increased up to the highest concentrations of IAA i.e., 100 mg L(-1). Regarding growing media, the leaf mould appeared the best in terms of its positive effect on establishment of rose cuttings by giving the maximum plant height (125.1 cm), plant spread (37 cm), primary shoots (5.2), secondary shoots (19.48) and survival percentage (85.67%), followed by soil + leaf mould, while soil media was least effective. PMID:19093472

  5. Physicochemical Properties and Applications of Poly(lactic-co-glycolic acid) for Use in Bone Regeneration

    PubMed Central

    Félix Lanao, Rosa P.; Jonker, Anika M.; Wolke, Joop G.C.; Jansen, John A.; van Hest, Jan C.M.

    2013-01-01

    Poly(lactic-co-glycolic acid) (PLGA) is the most often used synthetic polymer within the field of bone regeneration owing to its biocompatibility and biodegradability. As a consequence, a large number of medical devices comprising PLGA have been approved for clinical use in humans by the American Food and Drug Administration. As compared with the homopolymers of lactic acid poly(lactic acid) and poly(glycolic acid), the co-polymer PLGA is much more versatile with regard to the control over degradation rate. As a material for bone regeneration, the use of PLGA has been extensively studied for application and is included as either scaffolds, coatings, fibers, or micro- and nanospheres to meet various clinical requirements. PMID:23350707

  6. Callus induction and plant regeneration from mature zygotic embryos of a tetraploid Alstroemeria (A. pelegrina × A. psittacina).

    PubMed

    Hutchinson, M J; Tsujita, J M; Saxena, P K

    1994-12-01

    A simple procedure was developed to induce callus growth and whole plant regeneration for a tetraploid cultivar of Alstroemeria. The callus, induced from mature zygotic embryos cultured on a medium supplemented with 20 μM kinetin with 10 or 20 μM NAA, could be maintained for one year without any loss of regeneration potential. Maximum frequency of regeneration (40%) was obtained with calli maintained on the medium containing 20 μM kinetin and 20 μM NAA. Whole plant regeneration occurred via somatic embryogenesis in the absence of growth regulators and the plantlets grew to maturity and flowered in the greenhouse conditions. PMID:24192891

  7. Role of Bile Acids in Liver Injury and Regeneration following Acetaminophen Overdose

    PubMed Central

    Bhushan, Bharat; Borude, Prachi; Edwards, Genea; Walesky, Chad; Cleveland, Joshua; Li, Feng; Ma, Xiaochao; Apte, Udayan

    2014-01-01

    Bile acids play a critical role in liver injury and regeneration, but their role in acetaminophen (APAP)–induced liver injury is not known. We tested the effect of bile acid modulation on APAP hepatotoxicity using C57BL/6 mice, which were fed a normal diet, a 2% cholestyramine (CSA)–containing diet for bile acid depletion, or a 0.2% cholic acid (CA)–containing diet for 1 week before treatment with 400 mg/kg APAP. CSA-mediated bile acid depletion resulted in significantly higher liver injury and delayed regeneration after APAP treatment. In contrast, 0.2% CA supplementation in the diet resulted in a moderate delay in progression of liver injury and significantly higher liver regeneration after APAP treatment. Either CSA-mediated bile acid depletion or CA supplementation did not affect hepatic CYP2E1 levels or glutathione depletion after APAP treatment. CSA-fed mice exhibited significantly higher activation of c-Jun N-terminal protein kinases and a significant decrease in intestinal fibroblast growth factor 15 mRNA after APAP treatment. In contrast, mice fed a 0.2% CA diet had significantly lower c-Jun N-terminal protein kinase activation and 12-fold higher fibroblast growth factor 15 mRNA in the intestines. Liver regeneration after APAP treatment was significantly faster in CA diet–fed mice after APAP administration secondary to rapid cyclin D1 induction. Taken together, these data indicate that bile acids play a critical role in both initiation and recovery of APAP-induced liver injury. PMID:24007882

  8. Role of bile acids in liver injury and regeneration following acetaminophen overdose.

    PubMed

    Bhushan, Bharat; Borude, Prachi; Edwards, Genea; Walesky, Chad; Cleveland, Joshua; Li, Feng; Ma, Xiaochao; Apte, Udayan

    2013-11-01

    Bile acids play a critical role in liver injury and regeneration, but their role in acetaminophen (APAP)-induced liver injury is not known. We tested the effect of bile acid modulation on APAP hepatotoxicity using C57BL/6 mice, which were fed a normal diet, a 2% cholestyramine (CSA)-containing diet for bile acid depletion, or a 0.2% cholic acid (CA)-containing diet for 1 week before treatment with 400 mg/kg APAP. CSA-mediated bile acid depletion resulted in significantly higher liver injury and delayed regeneration after APAP treatment. In contrast, 0.2% CA supplementation in the diet resulted in a moderate delay in progression of liver injury and significantly higher liver regeneration after APAP treatment. Either CSA-mediated bile acid depletion or CA supplementation did not affect hepatic CYP2E1 levels or glutathione depletion after APAP treatment. CSA-fed mice exhibited significantly higher activation of c-Jun N-terminal protein kinases and a significant decrease in intestinal fibroblast growth factor 15 mRNA after APAP treatment. In contrast, mice fed a 0.2% CA diet had significantly lower c-Jun N-terminal protein kinase activation and 12-fold higher fibroblast growth factor 15 mRNA in the intestines. Liver regeneration after APAP treatment was significantly faster in CA diet-fed mice after APAP administration secondary to rapid cyclin D1 induction. Taken together, these data indicate that bile acids play a critical role in both initiation and recovery of APAP-induced liver injury. PMID:24007882

  9. In Vitro Callus Induction and Plant Regeneration from Stem Explants of Ceropegia noorjahaniae, a Critically Endangered Medicinal Herb.

    PubMed

    Chavan, Jaykumar J; Ahire, Mahendra L

    2016-01-01

    An efficient protocol has been developed for in vitro regeneration of a large number of plantlets of Ceropegia noorjahaniae Ansari via indirect organogenesis from stem explants excised from in vitro-germinated seedlings. The callus was efficiently induced from the stem explants using Murashige and Skoog (MS) medium supplemented with auxins and their combinations. The highest number of shoots (16.0 ± 0.2) and shoot length (5.5 ± 0.1 cm) was achieved when the callus was subcultured to MS medium supplemented with 6-benzylaminopurine, BAP (2.0 mg/l) and indole-3-acetic acid, IAA (0.2 mg/l). The in vitro-developed shoots were rooted well in half-strength MS medium supplemented with 1.0 mg/l of indole-3-butyric acid (IBA) and 0.3 mg/l of α-naphthalene acetic acid (NAA). The plantlets were successfully hardened with 82 % survival rate. This is the first report on the regeneration of plants through indirect shoot organogenesis from stem derived calli of C. noorjahaniae. PMID:27108329

  10. High frequency plant regeneration from mature seed of elite, recalcitrant Malaysian indica rice ( Oryza sativa L.) CV. MR 219.

    PubMed

    Sivakumar, P; Law, Y S; Ho, C-L; Harikrishna, Jennifer Ann

    2010-09-01

    An efficient in vitro plant regeneration system was established for elite, recalcitrant Malaysian indica rice, Oryza sativa L. CV. MR 219 using mature seeds as explant on Murashige and Skoog and Chu N6 media containing 2,4-dichlorophenoxy acetic acid and kinetin either alone or in different combinations. L-proline, casein hydrolysate and L-glutamine were added to callus induction media for enhancement of embryogenic callus induction. The highest frequency of friable callus induction (84%) was observed in N6 medium containing 2.5 mg l(-1) 2,4-dichlorophenoxy acetic acid, 0.2 mg l(-1) kinetin, 2.5 mg l(-1) L-proline, 300 mg l(-1) casein hydrolysate, 20 mg l(-1) L-glutamine and 30 g l(-1) sucrose under culture in continuous lighting conditions. The maximum regeneration frequency (71%) was observed, when 30-day-old N6 friable calli were cultured on MS medium supplemented with 3 mg l(-1) 6-benzyl aminopurine, 1 mg l(-1) naphthalene acetic acid, 2.5 mg l(-1) L-proline, 300 mg l(-1) casein hydrolysate and 3% maltose. Developed shoots were rooted in half strength MS medium supplemented with 2% sucrose and were successfully transplanted to soil with 95% survival. This protocol may be used for other recalcitrant indica rice genotypes and to transfer desirable genes in to Malaysian indica rice cultivar MR219 for crop improvement. PMID:20724277

  11. Regeneration of an aqueous solution from an acid gas absorption process by matrix stripping

    DOEpatents

    Rochelle, Gary T.; Oyenekan, Babatunde A.

    2011-03-08

    Carbon dioxide and other acid gases are removed from gaseous streams using aqueous absorption and stripping processes. By replacing the conventional stripper used to regenerate the aqueous solvent and capture the acid gas with a matrix stripping configuration, less energy is consumed. The matrix stripping configuration uses two or more reboiled strippers at different pressures. The rich feed from the absorption equipment is split among the strippers, and partially regenerated solvent from the highest pressure stripper flows to the middle of sequentially lower pressure strippers in a "matrix" pattern. By selecting certain parameters of the matrix stripping configuration such that the total energy required by the strippers to achieve a desired percentage of acid gas removal from the gaseous stream is minimized, further energy savings can be realized.

  12. Regeneration of different plant functional types in a Masson pine forest following pine wilt disease.

    PubMed

    Hu, Guang; Xu, Xuehong; Wang, Yuling; Lu, Gao; Feeley, Kenneth J; Yu, Mingjian

    2012-01-01

    Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation. PMID:22563499

  13. Regeneration of Different Plant Functional Types in a Masson Pine Forest Following Pine Wilt Disease

    PubMed Central

    Hu, Guang; Xu, Xuehong; Wang, Yuling; Lu, Gao; Feeley, Kenneth J.; Yu, Mingjian

    2012-01-01

    Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation. PMID:22563499

  14. Effect of retinoic acid on transglutaminase and ornithine decarboxylase activities during liver regeneration.

    PubMed

    Ohtake, Yosuke; Maruko, Akiko; Ohishi, Nao; Kawaguchi, Masasumi; Satoh, Tetsuharu; Ohkubo, Yasuhito

    2008-04-01

    Liver regeneration is regulated by several factors, including growth factors, cytokines, and post-translational modifications of several proteins. It is suggested that transglutaminase 2 (TG2) and ornithine decarboxylase (ODC) are involved in liver regeneration. To investigate the role of TG2 and ODC activities in regenerating liver, we used retinoic acid (RA), an inducer of TG2 and a suppressor of ODC. Regenerating rat liver was prepared by 70% partial hepatectomy (PH). Rats were sacrificed at 1, 2, 3, 4, and 6 days after surgery. RA was intraperitoneally injected immediately after PH. TG2 and ODC activities and products (epsilon-(gamma-glutamyl) lysine isopeptide (Gln-Lys) and polyamines, respectively) were examined at the indicated times. In RA-treated rat, DNA synthesis and ODC activity declined and the peak shifted to 2 days after PH, whereas TG2 activity increased at 1 day after PH. At that time, protein-polyamine, especially the protein-spermidine (SPD) bond, transiently decreased, whereas the formation of the Gln-Lys bond increased after PH. These results suggested that in regenerating liver, enhanced the formation of Gln-Lys bonds catalyzed by TG2 led to reduced DNA synthesis, whereas when ODC produced newly synthesized SPD, the inhibition of Gln-Lys bond production by the preferential formation of protein-SPD bonds led to an increase in DNA synthesis. PMID:18008394

  15. Bile Acid Flux Is Necessary for Normal Liver Regeneration

    PubMed Central

    Naugler, Willscott E.

    2014-01-01

    Background & Aims Many signals governing liver regeneration (LR) following 2/3 partial hepatectomy (PH) are recognized, but the primary signal(s) remains unknown. The aim of the study was to confirm that the remnant liver after PH lacks capacity to secrete the BA pool returning via the enterohepatic ciruculation (EHC), which may in turn stimulate LR. Methods After standard PH, BA flux was documented and BA signaling (Fgf15) and synthesis (Cyp7a) determined by qPCR. Rat biliary fistula (BF) and Asbt knockout mouse models interrupted the EHC prior to PH, and standard assays for LR employed along with complete RNA sequencing. CCl4 intoxication after BF tested the hypothesis in an alternate injury model. Results BA rise in systemic blood immediately following PH, confirming that the remnant liver cannot handle the BA returning via portal circulation. When the BA pool is drained prior to PH in the rat BF model, LR is markedly attenuated, a phenomenon reversed with duodenal BA replacement. Hepatocyte proliferation is similarly attenuated after PH in the Asbt knockout mouse as well as after CCl44 intoxication in rats with BF. Complete RNA sequencing in the rat PH model shows that early c-jun and AP-1 gene expression pathways are down regulated in the absence of BA, coincident with attenuated LR. Conclusions Absent BA return to the liver after PH or CCl4 injury markedly attenuates LR, though hepatocyte proliferation still occurs, inferring that BA flux and signaling are not the sole signals governing LR. Transcriptional networks involving c-jun and AP-1 are involved in the BA-specific effects on hepatocyte proliferation. PMID:24841254

  16. In vitro regeneration ability of diploid and autotetraploid plants of Cichorium intybus L.

    PubMed

    Ravandi, E Ghotbi; Rezanejad, F; Dehghan, E

    2014-01-01

    Polyploidy has played a significant role in the evolutionary history of plants and is a valuable tool for obtaining useful characteristics. Because of the novelty of polyploids, comparison of their in vitro culture response with diploids would be notable. In this study, leaf explants from diploid, autotetraploid and mixoploid plants of Cichorium intybus L. were cultured in vitro on the similar media and under same conditions. The ploidy level of the obtained calluses and regenerants were determined by flow cytometry analysis. The callogenic response of leaf explants cultured on the callus induction medium did not depend on the ploidy level of their parental plants. According to the flow cytometry analysis, the increased ploidy levels (4x) and (8x) were observed in the callus cultures with diploid and tetraploid origin, respectively. A considerable difference was observed between the ploidy level of mixoploid plants and their calluses, indicating the dominance of diploid cells in the callus tissue. The results showed that polyploidy led to the loss of organogenic potential as the tetraploid origin calluses failed to regenerate, while the diploid origin calluses successfully regenerated to whole plants. PMID:25016827

  17. [Transformation of sainfoin by Agrobacterium rhizogenes LBA9402 Bin19 and regeneration of transgenic plants].

    PubMed

    Xu, Z Q; Ma, H J; Hao, J G; Jia, J F

    2000-03-01

    Hypocotyl segments of Onobrychis viciaefolia were transformed by Agrobacterium rhizogenes LBA9402 which harboured pBin19 and pRi1855. Seedling age and preculture time of hypocotyl segments influenced the transformation frequency. Paper electrophoresis revealed that 70% of single hairy root cultures could synthesize agropine. Calli were induced from hairy root segments on MS medium containing 0-9.05 mumol/L 2,4-D and 0-2.22 mumol/L 6-BA at first, then they were transferred onto MS0 medium without kanamycin for regeneration. Constitution and concentration of phytohormones in callus induction media affected subsequent regeneration of calluses on MS0 medium remarkably. Regeneration frequency and shoot number per callus declined when 2,4-D concentration in callus induction media increased from 4.52 to 9.05 mumol/L, while they ascended when 6-BA in callus induction media increased from 0 to 2.22 mumol/L. On MS medium supplemented with 4.52 mumol/L 2,4-D and 2.22 mumol/L 6-BA, only 14.2% hairy root segments could produce calluses, but the regeneration frequency reached 58.1% and the shoot number per callus was 37.2. In 32 analysed plants regenerated from 8 kanamycin resistant hairy root lines, 25 were nptII positive and showed different copy numbers. PMID:12548853

  18. Regeneration of lactic and succinic acid-laden basic sorbents by leaching with a volatile base in an organic solvent

    SciTech Connect

    Husson, S.M.; King, C.J. |

    1998-08-01

    Leaching with an organic solution of a volatile base was explored as a method of regenerating tertiary amine and pyridyl sorbents. Experimental data are presented that show that regeneration efficiency correlated with the nonaqueous basicity of the regenerant as measured by the Gutmann donicity scale. Essentially complete regeneration of lactic acid-laden Dowex MWA-1 was achieved when 8--10 mol of trimethylamine were present for every mole of adsorbed acid; adequate (>70%) regeneration was obtained at a 2:1 molar ratio. The resulting trimethylamine-lactic acid complex can be thermally decomposed fully when trimethylamine is employed in an organic solvent instead of in water. A likely cause of the incomplete thermal decomposition of trimethylammonium lactate in previous, water-based systems is the aqueous environment in which the decomposition was performed.

  19. EFFECTS OF ACID PRECIPITATION ON PLANT DISEASES

    EPA Science Inventory

    Most plant diseases consist of delicate interactions between higher plants and microorganisms. Acidic precipitation represents an environmental stress that has been shown to affect expected development of some diseases and similar phenomena under experimental conditions. From the...

  20. The phosphoproteome in regenerating protoplasts from Physcomitrella patens protonemata shows changes paralleling postembryonic development in higher plants

    PubMed Central

    He, Yikun

    2014-01-01

    The moss Physcomitrella patens is an ideal model plant to study plant developmental processes. To better understand the mechanism of protoplast regeneration, a phosphoproteome analysis was performed. Protoplasts were prepared from protonemata. By 4 d of protoplast regeneration, the first cell divisions had ensued. Through a highly selective titanium dioxide (TiO2)-based phosphopeptide enrichment method and mass spectrometric technology, more than 300 phosphoproteins were identified as protoplast regeneration responsive. Of these, 108 phosphoproteins were present on day 4 but not in fresh protoplasts or those cultured for 2 d. These proteins are catalogued here. They were involved in cell-wall metabolism, transcription, signal transduction, cell growth/division, and cell structure. These protein functions are related to cell morphogenesis, organogenesis, and development adjustment. This study presents a comprehensive analysis of phosphoproteome involved in protoplast regeneration and indicates that the mechanism of plant protoplast regeneration is similar to that of postembryonic development. PMID:24700621

  1. C/sub 4/ photosynthesis in Euphorbia degeneri and E. remyi: a comparison of photosynthetic carbon metabolism in leaves, callus cultures and regenerated plants

    SciTech Connect

    Ruzin, S.E.

    1984-04-01

    Based on analysis of /sup 14/CO/sub 2/ fixation kinetics and assays of enzymes related to C/sub 4/ metabolism (NAD-ME, NADP-ME, NAD-MDH, NADP-MDH, AST, ALT), leaves and regenerated plants of Euphorbia degeneri exhibit a modified NADP-ME-type photosynthesis. Apparently, both aspartate and malate are used for transport of CO/sub 2/ to bundle sheath cells. Callus grown on either non-shoot-forming or shoot-forming media fixes CO/sub 2/ into RPP-cycle intermediates and sucrose, as well as malate and aspartate. /sup 14/CO/sub 2/ pulse/chase kinetics show no significant loss of label from C/sub 4/ acids throughout a one minute chase. Analysis of PEPCase revealed the presence of 2 isoenzymes in both leaf and regenerated plant tissues (K/sub m/ (PEP) = 0.080 and 0.550) but only one isoenzyme in callus (K/sub m/ = 0.100). It appears that C/sub 4/ photosynthesis does not occur in callus derived from this C/sub 4/ dicot but is regenerated concomitant with shoot regeneration, and ..beta..-carboxylation of PEP in callus, mediated by the low K/sub m/ isoenzyme of PEPCase, produces C/sub 4/ acids that are not involved in the CO/sub 2/ shuttle mechanism characteristic of C/sub 4/ photosynthesis. 161 references, 19 figures, 12 tables.

  2. Plant regeneration from cell suspension-derived protoplasts of Saintpaulia ionantha Wendl.

    PubMed

    Hoshino, Y; Nakano, M; Mii, M

    1995-03-01

    Friable calli were induced on leaf segments of Saintpaulia ionantha Wendl. on B5 medium containing 1 mg l(-1) 2,4-D and 2 g l(-1) casein hydrolysate. Cell suspension cultures were readily established from these friable calli and protoplasts could be isolated from the cells with yields of 1-3×10(7)/g f. wt.. By culturing in 0.1 % gellan gum-solidified B5 medium supplemented with 1 mg l(-1) 2,4-D and 0.1 M each of sucrose and mannitol at a density of 1×10(5)/ml, the protoplasts divided within 6 days and formed macro-colonies after 2 months of culture. Shoot regeneration from protoplast-derived calli was obtained by sequential treatment of the calli with plant growth regulators: initially with 1 mg l(-1) each of NAA and BA for 2 months followed by 0.01 mg l(-1) NAA and 5 mg l(-1) BA for 4 months. Regenerated plants were established after rooting of the shoots on half-strength MS medium, and successfully transferred to the greenhouse. The regenerated plants grew into flowering stage and showed the same phenotype as the parent plant. PMID:24185329

  3. Exergy analysis of internal regeneration in supercritical cycles of ORC power plant

    NASA Astrophysics Data System (ADS)

    Borsukiewicz-Gozdur, Aleksandra

    2012-09-01

    In the paper presented is an idea of organic Rankine cycle (ORC) operating with supercritical parameters and so called dry fluids. Discussed is one of the methods of improving the effectiveness of operation of supercritical cycle by application of internal regeneration of heat through the use of additional heat exchanger. The main objective of internal regenerator is to recover heat from the vapour leaving the turbine and its transfer to the liquid phase of working fluid after the circulation pump. In effect of application of the regenerative heat exchanger it is possible to obtain improved effectiveness of operation of the power plant, however, only in the case when the ORC plant is supplied from the so called sealed heat source. In the present paper presented is the discussion of heat sources and on the base of the case study of two heat sources, namely the rate of heat of thermal oil from the boiler and the rate of heat of hot air from the cooler of the clinkier from the cement production line having the same initial temperature of 260 oC, presented is the influence of the heat source on the justification of application of internal regeneration. In the paper presented are the calculations for the supercritical ORC power plant with R365mfc as a working fluid, accomplished has been exergy changes and exergy efficiency analysis with the view to select the most appropriate parameters of operation of the power plant for given parameters of the heat source.

  4. In vitro regeneration and Agrobacterium tumefaciens-mediated genetic transformation in asakura-sanshoo (Zanthoxylum piperitum (L.) DC. F. inerme Makino) an important medicinal plant

    PubMed Central

    Zeng, Xiaofang; Zhao, Degang

    2015-01-01

    Context: Asakura-sanshoo (Zanthoxylum piperitum [L.] DC. f. inerme Makino) is an important medicinal plant in East Asia. Transgenic technique could be applied to improve plant traits and analyze gene function. However, there is no report on regeneration and genetic transformation in Asakura-sanshoo. Aims: To establish a regeneration and Agrobacterium tumefaciens-mediated genetic transformation system in Asakura-sanshoo, which could be used for cultivar improvement and gene function analysis. Settings and Design: The various combinations of indole-3-butyric acid (IBA), 6-benzylaminopurine (BA) and naphthalene acetic acid (NAA) were explored for the optimal plant regeneration from petiole and stem of Asakura-sanshoo. The half-strength woody plant medium (WPM) with different concentrations of NAA and IBA was used to induce root. For genetic transformation, A. tumefaciens strain EHA-105 harboring the plasmid pBin-Ex-H-ipt which carries the isopentenyl transferase (ipt) gene, β-glucuronidase (GUS) gene and kanamycin resistance gene neomycin phosphotransferase II (NPTII) were used. The transformation efficiency was detected by the kanamycin resistant frequency. Materials and Methods: Petioles and stems were obtained from the in vitro cultured Asakura-sanshoo. The petiole and stem segments were precultured for 3 days, and then inflected using the bacterium at the concentration of OD600 0.5–0.8 for 10 min, followed by 3 days co-cultivation. Selection of the transgenic plants was carried out after 7 days the regeneration using gradient kanamycin at 30 mg/L and 50 mg/L, respectively. Successful transformed plants were confirmed by GUS histochemical assays, polymerase chain reaction (PCR), reverse transcription-PCR (RT-PCR), and Southern blotting analysis. Results: The highest shoots regeneration was obtained on WPM supplement with 0.5 mg/L BA and 0.2 mg/L NAA. The optimal rooting medium was half strength macro-element WPM. The kanamycin resistant frequency of petiole and

  5. Alpha-lipoic acid loaded in chitosan conduit enhances sciatic nerve regeneration in rat

    PubMed Central

    Azizi, Saeed; Heshmatian, Behnam; Amini, Keyvan; Raisi, Abbas; Azimzadeh, Mohammad

    2015-01-01

    Objective(s): To investigate the effect of topical administration of alpha-lipoic acid into chitosan conduit on peripheral nerve regeneration using a rat sciatic nerve transection model. Materials and Methods: Forty five Wistar rats were divided into three experimental groups randomly. A 10-mm gap of sciatic nerve was bridged with a chitosan conduit following surgical preparation and anesthesia. In treatment group, the conduit was filled with 30 µl alpha-lipoic acid (10 mg/kg/bw).It was filled with 30 µl phosphate buffered saline solution in control group. In Sham group sciatic nerve was just exposed. Results: The recovery of nerve function was faster in treatment group than in control, at 4 and 8 weeks after surgery (P-value<0.05). Conduction velocity was better in treatment group than in control group at 4 and 12 weeks (P-value<0.05). Recovery index was higher in treatment group than the control group, 8 weeks after surgery (P-value <0.05). Greater nerve fiber diameter, axon diameter, and myelin sheath thickness were observed in treatment group compared to control group at 8 and 12 weeks after surgery (P-value<0.05). The immunoreactivity of regenerated axons and myelin sheath in treatment group were far more similar to sham group. Conclusion: Alpha-lipoic acid when loaded in a chitosan conduit could improve transected sciatic nerve regeneration in rat. PMID:25945234

  6. Regeneration of transgenic cassava plants (Manihot esculenta Crantz) from microbombarded embryogenic suspension cultures.

    PubMed

    Schöpke, C; Taylor, N; Cárcamo, R; Konan, N K; Marmey, P; Henshaw, G G; Beachy, R N; Fauquet, C

    1996-06-01

    A protocol was established for the introduction of DNA into embryogenic suspension-derived tissues of cassava via microparticle bombardment, for the selection of genetically transformed cells, and for the regeneration of fully transgenic plants from these cells. The plasmid DNA used for bombardment contained a gene encoding neomycin phosphotransferase (nptII) and a gene encoding beta-glucuronidase (uidA). Selection of bombarded tissue with paromomycin resulted in the establishment of putative transgenic embryogenic calli. In most of these calli, beta-glucuronidase was detected histochemically. Molecular analysis of paromomycin-resistant embryogenic calli and of plants regenerated from these calli, confirmed the stable integration of bombarded DNA into the cassava genome. PMID:9630980

  7. Fertile plant regeneration from cryopreserved calli of Oryza rufipogon Griff. and assessment of variation in the progeny of regenerated plants.

    PubMed

    Zeliang, P K; Pattanayak, A; Iangrai, B; Khongwir, E A; Sarma, B K

    2010-12-01

    A protocol was developed for preservation of calli of Oryza rufipogon Griff. in liquid nitrogen (-196°C). Optimal conditions for cryoprotection, pre-freezing and post-thaw recovery of calli were identified. Cryoprotectant treatment at low temperature, pre-freezing in isopropanol bath for 1 h at -70°C, rapid thawing and proper removal of cryoprotectant were critical for post-thaw survival. Genetic fidelity of the R1 plants obtained from cryopreserved, cryoprotectant-treated and untreated calli was assessed by phenotypic and molecular characterization. Comparison of phenotypic characters with seed-derived control plants showed no significant variation in the agronomic characters, but seed physical characters showed significant reduction in all the in vitro generated plants. Molecular data generated using 26 rice simple sequence repeat markers showed 4.78-7.25% change from control. Results suggested that both callus induction and cryopreservation induced heritable variations in O. rufipogon. In addition, a combination of phenotypic and molecular characterization using an appropriate marker provided better insight into genetic fidelity of recovered plants. PMID:20960202

  8. Citric acid-based hydroxyapatite composite scaffolds enhance calvarial regeneration.

    PubMed

    Sun, Dawei; Chen, Yuhui; Tran, Richard T; Xu, Song; Xie, Denghui; Jia, Chunhong; Wang, Yuchen; Guo, Ying; Zhang, Zhongmin; Guo, Jinshan; Yang, Jian; Jin, Dadi; Bai, Xiaochun

    2014-01-01

    Citric acid-based polymer/hydroxyapatite composites (CABP-HAs) are a novel class of biomimetic composites that have recently attracted significant attention in tissue engineering. The objective of this study was to compare the efficacy of using two different CABP-HAs, poly (1,8-octanediol citrate)-click-HA (POC-Click-HA) and crosslinked urethane-doped polyester-HA (CUPE-HA) as an alternative to autologous tissue grafts in the repair of skeletal defects. CABP-HA disc-shaped scaffolds (65 wt.-% HA with 70% porosity) were used as bare implants without the addition of growth factors or cells to renovate 4 mm diameter rat calvarial defects (n = 72, n = 18 per group). Defects were either left empty (negative control group), or treated with CUPE-HA scaffolds, POC-Click-HA scaffolds, or autologous bone grafts (AB group). Radiological and histological data showed a significant enhancement of osteogenesis in defects treated with CUPE-HA scaffolds when compared to POC-Click-HA scaffolds. Both, POC-Click-HA and CUPE-HA scaffolds, resulted in enhanced bone mineral density, trabecular thickness, and angiogenesis when compared to the control groups at 1, 3, and 6 months post-trauma. These results show the potential of CABP-HA bare implants as biocompatible, osteogenic, and off-shelf-available options in the repair of orthopedic defects. PMID:25372769

  9. Regeneration of plantlets from the callus of stem segments of adult plants of Ficus religiosa L.

    PubMed

    Jaiswal, V S; Narayan, P

    1985-10-01

    Stem segments of adult plants of Ficus religiosa L. cultured on MS medium containing 1.0 mg/l 2,4-D produced callus. Shoots were regenerated when the induced calli were transferred to medium supplemented with 0.05 to 2.0 mg/l BAP. Callus derived shoots produced roots and developed into plantlets when transferred to medium supplemented with 1.0 mg/l NAA. PMID:24253982

  10. Salicylic Acid-Based Polymers for Guided Bone Regeneration Using Bone Morphogenetic Protein-2

    PubMed Central

    Subramanian, Sangeeta; Mitchell, Ashley; Yu, Weiling; Snyder, Sabrina; Uhrich, Kathryn

    2015-01-01

    Bone morphogenetic protein-2 (BMP-2) is used clinically to promote spinal fusion, treat complex tibia fractures, and to promote bone formation in craniomaxillofacial surgery. Excessive bone formation at sites where BMP-2 has been applied is an established complication and one that could be corrected by guided tissue regeneration methods. In this study, anti-inflammatory polymers containing salicylic acid [salicylic acid-based poly(anhydride-ester), SAPAE] were electrospun with polycaprolactone (PCL) to create thin flexible matrices for use as guided bone regeneration membranes. SAPAE polymers hydrolyze to release salicylic acid, which is a nonsteroidal anti-inflammatory drug. PCL was used to enhance the mechanical integrity of the matrices. Two different SAPAE-containing membranes were produced and compared: fast-degrading (FD-SAPAE) and slow-degrading (SD-SAPAE) membranes that release salicylic acid at a faster and slower rate, respectively. Rat femur defects were treated with BMP-2 and wrapped with FD-SAPAE, SD-SAPAE, or PCL membrane or were left unwrapped. The effects of different membranes on bone formation within and outside of the femur defects were measured by histomorphometry and microcomputed tomography. Bone formation within the defect was not affected by membrane wrapping at BMP-2 doses of 12 μg or more. In contrast, the FD-SAPAE membrane significantly reduced bone formation outside the defect compared with all other treatments. The rapid release of salicylic acid from the FD-SAPAE membrane suggests that localized salicylic acid treatment during the first few days of BMP-2 treatment can limit ectopic bone formation. The data support development of SAPAE polymer membranes for guided bone regeneration applications as well as barriers to excessive bone formation. PMID:25813520

  11. Dynamic of Plant Composition and Regeneration following Windthrow in a Temperate Beech Forest

    PubMed Central

    Mollaei Darabi, Sakineh; Kooch, Yahya; Hosseini, Seyed Mohsen

    2014-01-01

    The effects of soil pedoturbation (i.e., pit and mound microtopography, PM) on development of herbaceous plant species and woody species regeneration were examined in a temperate beech forest (Fagus orientalis Lipsky) in northern Iran. We recorded the vegetation in 20 pairs of disturbed and adjacent undisturbed plots and established a chronosequence of PM ages to study the effect of time since microsite formation on cover percent of herbaceous plants and woody regeneration status. According to our findings, Carex acutiformis L., Sambucus ebulus L., Brachypodium pinnatum L., and Cyclamen coum L. are found only in the PM microsites, whereas the Equisetum ramosissimum L. is recorded only under closed canopy. The coverage percent of Rubus caesius L. increased in PM microsites compared to closed canopy intensively. In addition, Albizia julibrissin Durazz. is detected in PM microsite, whereas the Acer cappadocicum B. and Prunus persica L. species were recorded only under closed canopy. We found significant differences in understory species diversity between different ages of PM, and disturbed and adjacent undisturbed plots. Our study supports that the PM complex will create a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species. PMID:27379260

  12. Dynamic of Plant Composition and Regeneration following Windthrow in a Temperate Beech Forest.

    PubMed

    Mollaei Darabi, Sakineh; Kooch, Yahya; Hosseini, Seyed Mohsen

    2014-01-01

    The effects of soil pedoturbation (i.e., pit and mound microtopography, PM) on development of herbaceous plant species and woody species regeneration were examined in a temperate beech forest (Fagus orientalis Lipsky) in northern Iran. We recorded the vegetation in 20 pairs of disturbed and adjacent undisturbed plots and established a chronosequence of PM ages to study the effect of time since microsite formation on cover percent of herbaceous plants and woody regeneration status. According to our findings, Carex acutiformis L., Sambucus ebulus L., Brachypodium pinnatum L., and Cyclamen coum L. are found only in the PM microsites, whereas the Equisetum ramosissimum L. is recorded only under closed canopy. The coverage percent of Rubus caesius L. increased in PM microsites compared to closed canopy intensively. In addition, Albizia julibrissin Durazz. is detected in PM microsite, whereas the Acer cappadocicum B. and Prunus persica L. species were recorded only under closed canopy. We found significant differences in understory species diversity between different ages of PM, and disturbed and adjacent undisturbed plots. Our study supports that the PM complex will create a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species. PMID:27379260

  13. An Efficient In Vitro Plantlet Regeneration from Shoot Tip Cultures of Curculigo latifolia, a Medicinal Plant

    PubMed Central

    Babaei, Nahid; Psyquay Abdullah, Nur Ashikin; Saleh, Ghizan; Lee Abdullah, Thohirah

    2014-01-01

    A procedure was developed for in vitro propagation of Curculigo latifolia through shoot tip culture. Direct regeneration and indirect scalp induction of Curculigo latifolia were obtained from shoot tip grown on MS medium supplemented with different concentrations and combinations of thidiazuron and indole-3-butyric acid. Maximum response for direct regeneration in terms of percentage of explants producing shoot, shoot number, and shoot length was obtained on MS medium supplemented with combination of thidiazuron (0.5 mg L−1) and indole-3-butyric acid (0.25 mg L−1) after both 10 and 14 weeks of cultures. Indole-3-butyric acid in combination with thidiazuron exhibited a synergistic effect on shoot regeneration. The shoot tips were able to induce maximum scalp from basal end of explants on the medium with 2 mg L−1 thidiazuron. Cultures showed that shoot number, shoot length, and scalp size increased significantly after 14 weeks of culture. Transferring of the shoots onto the MS medium devoid of growth regulators resulted in the highest percentage of root induction and longer roots, while medium supplemented with 0.25 mg L−1 IBA produced more numbers of roots. PMID:24723799

  14. An efficient in vitro plantlet regeneration from shoot tip cultures of Curculigo latifolia, a medicinal plant.

    PubMed

    Babaei, Nahid; Abdullah, Nur Ashikin Psyquay; Saleh, Ghizan; Abdullah, Thohirah Lee

    2014-01-01

    A procedure was developed for in vitro propagation of Curculigo latifolia through shoot tip culture. Direct regeneration and indirect scalp induction of Curculigo latifolia were obtained from shoot tip grown on MS medium supplemented with different concentrations and combinations of thidiazuron and indole-3-butyric acid. Maximum response for direct regeneration in terms of percentage of explants producing shoot, shoot number, and shoot length was obtained on MS medium supplemented with combination of thidiazuron (0.5 mg L(-1)) and indole-3-butyric acid (0.25 mg L(-1)) after both 10 and 14 weeks of cultures. Indole-3-butyric acid in combination with thidiazuron exhibited a synergistic effect on shoot regeneration. The shoot tips were able to induce maximum scalp from basal end of explants on the medium with 2 mg L(-1) thidiazuron. Cultures showed that shoot number, shoot length, and scalp size increased significantly after 14 weeks of culture. Transferring of the shoots onto the MS medium devoid of growth regulators resulted in the highest percentage of root induction and longer roots, while medium supplemented with 0.25 mg L(-1) IBA produced more numbers of roots. PMID:24723799

  15. Sialic Acids in the Brain: Gangliosides and Polysialic Acid in Nervous System Development, Stability, Disease, and Regeneration

    PubMed Central

    Gerardy-Schahn, Rita; Hildebrandt, Herbert

    2014-01-01

    Every cell in nature carries a rich surface coat of glycans, its glycocalyx, which constitutes the cell's interface with its environment. In eukaryotes, the glycocalyx is composed of glycolipids, glycoproteins, and proteoglycans, the compositions of which vary among different tissues and cell types. Many of the linear and branched glycans on cell surface glycoproteins and glycolipids of vertebrates are terminated with sialic acids, nine-carbon sugars with a carboxylic acid, a glycerol side-chain, and an N-acyl group that, along with their display at the outmost end of cell surface glycans, provide for varied molecular interactions. Among their functions, sialic acids regulate cell-cell interactions, modulate the activities of their glycoprotein and glycolipid scaffolds as well as other cell surface molecules, and are receptors for pathogens and toxins. In the brain, two families of sialoglycans are of particular interest: gangliosides and polysialic acid. Gangliosides, sialylated glycosphingolipids, are the most abundant sialoglycans of nerve cells. Mouse genetic studies and human disorders of ganglioside metabolism implicate gangliosides in axon-myelin interactions, axon stability, axon regeneration, and the modulation of nerve cell excitability. Polysialic acid is a unique homopolymer that reaches >90 sialic acid residues attached to select glycoproteins, especially the neural cell adhesion molecule in the brain. Molecular, cellular, and genetic studies implicate polysialic acid in the control of cell-cell and cell-matrix interactions, intermolecular interactions at cell surfaces, and interactions with other molecules in the cellular environment. Polysialic acid is essential for appropriate brain development, and polymorphisms in the human genes responsible for polysialic acid biosynthesis are associated with psychiatric disorders including schizophrenia, autism, and bipolar disorder. Polysialic acid also appears to play a role in adult brain plasticity

  16. Transformation of pecan and regeneration of transgenic plants.

    PubMed

    McGranahan, G H; Leslie, C A; Dandekar, A M; Uratsu, S L; Yates, I E

    1993-09-01

    A gene transfer system developed for walnut (Juglans regia L.) was successfully applied to pecan (Carya illinoensis [Wang] K. Koch). Repetitively embryogenic somatic embryos derived from open-pollinated seed of 'Elliott', 'Wichita', and 'Schley' were co-cultivated with Agrobacterium strain EHA 101/pCGN 7001, which contains marker genes for beta-glucuronidase activity and resistance to kanamycin. Several modifications of the standard walnut transformation techniques were tested, including a lower concentration of kanamycin and a modified induction medium, but these treatments had no measurable effect on efficiency of transformation. Nineteen of the 764 viable inoculated embryos produced transgenic subclones; 13 of these were from the line 'Elliott'6, 3 from 'Schley'5/3, and 3 from 'Wichita'9. Transgenic embryos of 'Wichita'9 germinated most readily and three subclones were successfully micropropagated. Three transgenic plants of one of these subclones were obtained by grafting the tissue cultured shoots to seedling pecan rootstock in the greenhouse. Gene insertion, initially detected by GUS activity, was confirmed by detection of integrated T-DNA sequences using Southern analysis. PMID:24201878

  17. Impaired reductive regeneration of ascorbic acid in the Goto-Kakizaki diabetic rat.

    PubMed Central

    Kashiba, M; Oka, J; Ichikawa, R; Kageyama, A; Inayama, T; Kageyama, H; Ishikawa, T; Nishikimi, M; Inoue, M; Inoue, S

    2000-01-01

    Ascorbic acid (AA) is a naturally occurring major antioxidant that is essential for the scavenging of toxic free radicals in both plasma and tissues. AA levels in plasma and tissues have been reported to be significantly lower than normal in diabetic animals and humans, and might contribute to the complications found at the late stages of diabetes. In this study, plasma and hepatic AA levels and AA regeneration were studied in the Goto-Kakizaki diabetic rat (GK rat) to elucidate the mechanism of decreasing plasma and hepatic AA levels in diabetes. AA concentrations in the plasma and liver were significantly lower in GK than in control rats. AA levels in primary cultured hepatocytes derived from GK rats were lower than those derived from control Wistar rats with or without dehydroascorbic acid (DHA) in the medium. Among various enzyme activities that reduce DHA to AA, the NADPH-dependent regeneration of AA in the liver was significantly suppressed in GK rats. Northern blot analysis revealed that only the expression of 3-alpha-hydroxysteroid dehydrogenase (AKR) was significantly suppressed in these rats. These results suggest that decreased AA-regenerating activity, probably through decreased expression of AKR, contributes to the decreased AA levels and increased oxidative stress in GK rats. PMID:11023815

  18. Carbon dioxide absorber and regeneration assemblies useful for power plant flue gas

    DOEpatents

    Vimalchand, Pannalal; Liu, Guohai; Peng, Wan Wang

    2012-11-06

    Disclosed are apparatus and method to treat large amounts of flue gas from a pulverized coal combustion power plant. The flue gas is contacted with solid sorbents to selectively absorb CO.sub.2, which is then released as a nearly pure CO.sub.2 gas stream upon regeneration at higher temperature. The method is capable of handling the necessary sorbent circulation rates of tens of millions of lbs/hr to separate CO.sub.2 from a power plant's flue gas stream. Because pressurizing large amounts of flue gas is cost prohibitive, the method of this invention minimizes the overall pressure drop in the absorption section to less than 25 inches of water column. The internal circulation of sorbent within the absorber assembly in the proposed method not only minimizes temperature increases in the absorber to less than 25.degree. F., but also increases the CO.sub.2 concentration in the sorbent to near saturation levels. Saturating the sorbent with CO.sub.2 in the absorber section minimizes the heat energy needed for sorbent regeneration. The commercial embodiments of the proposed method can be optimized for sorbents with slower or faster absorption kinetics, low or high heat release rates, low or high saturation capacities and slower or faster regeneration kinetics.

  19. Regeneration of the intestinal mucosa in Eimeria and E. Coli challenged broilers supplemented with amino acids.

    PubMed

    Gottardo, E T; Prokoski, K; Horn, D; Viott, A D; Santos, T C; Fernandes, J I M

    2016-05-01

    The aim of this study was to evaluate the regeneration of the intestinal mucosa in Eimeria and E. coli challenged broilers supplemented with glutamine, arginine, and threonine. Six hundred male broilers at one d of age from the Cobb strain were utilized. The design was completely randomized using a 2×3 factorial design (unchallenged and challenged and 3 diets). A commercial diet was used as a control and 2 other diets were formulated with glutamine (1.5 and 3% Aminogut®), arginine (1 and 2% L-Arginine), and threonine (1 and 2% L-threonine). The animals that consumed diets supplemented with amino acids presented better (P<0.05) feed conversion in the period from one to 42 d of age. The ability of cell proliferation and the villus:crypt ratio in response to enteric challenge were greater (P<0.05) for broilers that received diets supplemented with amino acids. High levels of amino acids in the experimental feeds reflected in greater protein levels in poultry house litter, and they did not interfere with ammonia production. The supplementation of diets with trophic amino acids can positively contribute to the regeneration and proliferation of the intestinal mucosa in broilers and to the maintenance of zootechnical performance when submitted to enteric challenges. PMID:26846258

  20. Phenylbutyrate exerts adverse effects on liver regeneration and amino acid concentrations in partially hepatectomized rats.

    PubMed

    Holecek, Milan; Vodenicarovova, Melita

    2016-06-01

    Phenylbutyrate is recommended in urea cycle disorders and liver injury to enhance nitrogen disposal by the urine. However, hypothetically there may be adverse responses to the use of phenylbutyrate in the treatment of liver disease because of its role as a histone deacetylase inhibitor and its stimulatory effect on branched-chain alpha-keto acid dehydrogenase, the rate-limiting enzyme in the catabolism of branched-chain amino acids (BCAA; valine, leucine and isoleucine). We report the effects of phenylbutyrate on liver regeneration and amino acid levels in plasma of partially hepatectomized (PH) rats. Phenylbutyrate or saline was administered at 12-h intervals to PH or laparotomized rats. Phenylbutyrate delayed the onset of liver regeneration compared to the saline-treated controls, as indicated by lower hepatic DNA specific activities 18 and 24( ) h post-PH, decreased hepatic fractional protein synthesis rates 24 h post-PH and lowered the increases in liver weights and hepatic protein and DNA contents 48 h after PH. Hepatic DNA fragmentation (a hallmark of apoptosis) was higher in the phenylbutyrate-treated animals than in controls. Phenylbutyrate decreased the glutamine and BCAA concentrations and the ratio of the BCAA to aromatic amino acids (phenylalanine and tyrosine) in the blood plasma in both hepatectomized and laparotomized animals. In conclusion, the delayed onset of liver regeneration and the decrease in BCAA/AAA ratio in blood suggest that phenylbutyrate administration may be disastrous in subjects with acute hepatic injury and BCAA supplementation is needed when phenylbutyrate is used therapeutically. PMID:27381898

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

    PubMed Central

    Gallie, Daniel R.

    2013-01-01

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

  2. Loss of CMD2-mediated resistance to cassava mosaic disease in plants regenerated through somatic embryogenesis.

    PubMed

    Beyene, Getu; Chauhan, Raj Deepika; Wagaba, Henry; Moll, Theodore; Alicai, Titus; Miano, Douglas; Carrington, James C; Taylor, Nigel J

    2016-09-01

    Cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) are the two most important viral diseases affecting cassava production in Africa. Three sources of resistance are employed to combat CMD: polygenic recessive resistance, termed CMD1, the dominant monogenic type, named CMD2, and the recently characterized CMD3. The farmer-preferred cultivar TME 204 carries inherent resistance to CMD mediated by CMD2, but is highly susceptible to CBSD. Selected plants of TME 204 produced for RNA interference (RNAi)-mediated resistance to CBSD were regenerated via somatic embryogenesis and tested in confined field trials in East Africa. Although micropropagated, wild-type TME 204 plants exhibited the expected levels of resistance, all plants regenerated via somatic embryogenesis were found to be highly susceptible to CMD. Glasshouse studies using infectious clones of East African cassava mosaic virus conclusively demonstrated that the process of somatic embryogenesis used to regenerate cassava caused the resulting plants to become susceptible to CMD. This phenomenon could be replicated in the two additional CMD2-type varieties TME 3 and TME 7, but the CMD1-type cultivar TMS 30572 and the CMD3-type cultivar TMS 98/0505 maintained resistance to CMD after passage through somatic embryogenesis. Data are presented to define the specific tissue culture step at which the loss of CMD resistance occurs and to show that the loss of CMD2-mediated resistance is maintained across vegetative generations. These findings reveal new aspects of the widely used technique of somatic embryogenesis, and the stability of field-level resistance in CMD2-type cultivars presently grown by farmers in East Africa, where CMD pressure is high. PMID:26662210

  3. Sustained, localized salicylic acid delivery enhances diabetic bone regeneration via prolonged mitigation of inflammation.

    PubMed

    Yu, Weiling; Bien-Aime, Stephan; Mattos, Marcelo; Alsadun, Sarah; Wada, Keisuke; Rogado, Sarah; Fiorellini, Joseph; Graves, Dana; Uhrich, Kathryn

    2016-10-01

    Diabetes is a metabolic disorder caused by insulin resistance and/or deficiency and impairs bone quality and bone healing due to altered gene expression, reduced vascularization, and prolonged inflammation. No effective treatments for diabetic bone healing are currently available, and most existing treatments do not directly address the diabetic complications that impair bone healing. We recently demonstrated that sustained and localized delivery of salicylic acid (SA) via an SA-based polymer provides a low-cost approach to enhance diabetic bone regeneration. Herein, we report mechanistic studies that delve into the biological action and local pharmacokinetics of SA-releasing polymers shown to enhance diabetic bone regeneration. The results suggest that low SA concentrations were locally maintained at the bone defect site for more than 1 month. As a result of the sustained SA release, a significantly reduced inflammation was observed in diabetic animals, which in turn, yielded reduced osteoclast density and activity, as well as increased osteoblastogenesis. Based upon these results, localized and sustained SA delivery from the SA-based polymer effectively improved bone regeneration in diabetic animals by affecting both osteoclasts and osteoblasts, thereby providing a positive basis for clinical treatments. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2595-2603, 2016. PMID:27194511

  4. Periodontal healing following guided tissue regeneration with citric acid and fibronectin application.

    PubMed

    Caffesse, R G; Nasjleti, C E; Anderson, G B; Lopatin, D E; Smith, B A; Morrison, E C

    1991-01-01

    This study was undertaken to determine the effects of guided tissue regeneration (GTR) with and without citric acid conditioning and autologous fibronectin application. The study subjects were four female beagle dogs with spontaneous periodontitis. The dogs were given thorough root debridement and 4 weeks later, mucoperiosteal flaps were raised on both sides of the mandible involving the 2nd, 3rd, and 4th premolar and 1st molar teeth. After debridement, notches were placed on the roots at the level of supporting bone. Citric acid (pH 1) was topically applied for 3 minutes on the exposed root surfaces of one side (experimental). The roots were irrigated with normal saline solution. Both the root surfaces and the inner surface of the flap were then bathed in autologous fibronectin in saline. Following this, Gore-Tex periodontal material was adapted to the roots of each tooth and sutured. The contralateral side, serving as control, was treated by surgery and application of Gore-Tex periodontal material only. All membranes were removed 1 month after surgery, and the dogs sacrificed at 3 months. Both mesio-distal and bucco-lingual microscopic histological sections were evaluated by descriptive histology, and linear measurements and surface area determination of the furcal tissues were made. Periodontal healing following the use of GTR procedure resulted in an increase in connective tissue and alveolar bone regeneration. Adjunctive critic acid plus autologous fibronectin produced slightly better results, but these differences were not statistically significant for this sample. PMID:2002428

  5. Plant regeneration methods for rapid generation of a large scale Ds transposant population in rice.

    PubMed

    Xuan, Yuan Hu; Huang, Jin; Yi, Gihwan; Park, Dong-Soo; Park, Soo Kwon; Eun, Moo Young; Yun, Doh Won; Lee, Gang-Seob; Kim, Tae Ho; Han, Chang-deok

    2013-01-01

    To mutagenize rice genomes, a two-element system is utilized. This system comprises an immobile Ac element driven by the CaMV 35S promoter, and a gene trap Ds carrying a partial intron with alternative splice acceptors fused to the GUS coding region. Rapid, large-scale generation of a Ds transposant population was achieved using a plant regeneration procedure involving the tissue culture of seed-derived calli carrying Ac and Ds elements. During tissue cultures, Ds mobility accompanies changes in methylation patterns of a terminal region of Ds, where over 70% of plants contained independent Ds insertions. In the transposon population, around 12% of plants expressed GUS at the early seedling stage. A flanking-sequence-tag (FST) database has been established by cloning over 19,968 Ds insertion sites and the Ds map shows relatively uniform distribution across the rice chromosomes. PMID:23918423

  6. Efficient in vitro plant regeneration through leaf base derived callus cultures of abiotic stress sensitive popular Asian Indica rice cultivar IR 64 (Oryza sativa L.).

    PubMed

    Mohana Priya, A; Karutha Pandian, S; Ramesh, M

    2011-12-01

    A simple and efficient protocol has been developed for high frequency plant regeneration through callus cultures derived from leaf bases of abiotic stress sensitive Asian indica rice variety IR 64. Leaf base segments (4-5 mm diameter) were obtained from 6-day-old dark grown seedlings germinated on halfstrength Murashige and Skoog medium and cultured on MS medium supplemented with different concentrations of 2,4-Dichlorophenoxyacetic acid (2.2-18 μM) and Kinetin (0.2-1.7 μM). Among the various combinations, 13.5 μM 2,4-D and 1.3 μM Kn resulted in high callus induction frequency (87.5%) with a maximum fresh weight of 0.22 g per segment. The regeneration frequency was 75.5% with multiple shoots within 3 weeks of transfer on MS medium supplemented with 13.3 μM 6-benzylamino purine and 8 μM Naphthaleneacetic acid. The shoots readily rooted on half-strength MS medium without any hormonal supplements. In vitro regenerated plantlets with multiple shoots and roots were transferred to sterile soil and vermiculite mix and maintained in shade house for 30 days. Complete plantlets were then transferred to nursery and acclimatized to the external environment until seed set. RAPD profile reveals monomorphism and thus confirming the genetic stability of the regenerated plants. This method has the potential for both direct as well as indirect method of transformation for the production of genetically modified plants. PMID:22119872

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

    PubMed

    Mathew, Sindhu; Zakaria, Zainul Akmar

    2015-01-01

    Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food. PMID:25467926

  8. Effects of high-frequency understorey fires on woody plant regeneration in southeastern Amazonian forests.

    PubMed

    Balch, Jennifer K; Massad, Tara J; Brando, Paulo M; Nepstad, Daniel C; Curran, Lisa M

    2013-06-01

    Anthropogenic understorey fires affect large areas of tropical forest, yet their effects on woody plant regeneration post-fire remain poorly understood. We examined the effects of repeated experimental fires on woody stem (less than 1 cm at base) mortality, recruitment, species diversity, community similarity and regeneration mode (seed versus sprout) in Mato Grosso, Brazil. From 2004 to 2010, forest plots (50 ha) were burned twice (B2) or five times (B5), and compared with an unburned control (B0). Stem density recovered within a year after the first burn (initial density: 12.4-13.2 stems m(-2)), but after 6 years, increased mortality and decreased regeneration--primarily of seedlings--led to a 63 per cent and 85 per cent reduction in stem density in B2 and B5, respectively. Seedlings and sprouts across plots in 2010 displayed remarkable community similarity owing to shared abundant species. Although the dominant surviving species were similar across plots, a major increase in sprouting occurred--almost three- and fourfold greater in B2 and B5 than in B0. In B5, 29 species disappeared and were replaced by 11 new species often present along fragmented forest edges. By 2010, the annual burn regime created substantial divergence between the seedling community and the initial adult tree community (greater than or equal to 20 cm dbh). Increased droughts and continued anthropogenic ignitions associated with frontier land uses may promote high-frequency fire regimes that may substantially alter regeneration and therefore successional processes. PMID:23610167

  9. Genetic stability and phytochemical analysis of the in vitro regenerated plants of Dendrobium nobile Lindl., an endangered medicinal orchid

    PubMed Central

    Bhattacharyya, Paromik; Kumaria, Suman; Diengdoh, Reemavareen; Tandon, Pramod

    2014-01-01

    An efficient genetically stable regeneration protocol with increased phytochemical production has been established for Dendrobium nobile, a highly prized orchid for its economic and medicinal importance. Protocorm like bodies (PLBs) were induced from the pseudostem segments using thidiazuron (TDZ; 1.5 mg/l), by-passing the conventional auxin–cytokinin complement approach for plant regeneration. Although, PLB induction was observed at higher concentrations of TDZ, plantlet regeneration from those PLBs was affected adversely. The best rooting (5.41 roots/shoot) was achieved in MS medium with 1.5 mg/l TDZ and 0.25% activated charcoal. Plantlets were successfully transferred to a greenhouse with a survival rate of 84.3%, exhibiting normal development. Genetic stability of the regenerated plants was investigated using randomly amplified polymorphic DNA (RAPD) and start codon targeted (SCoT) polymorphism markers which detected 97% of genetic fidelity among the regenerants. The PIC values of RAPD and SCoT primers were recorded to be 0.92 and 0.76 and their Rp values ranged between 3.66 and 10, and 4 and 12 respectively. The amplification products of the regenerated plants showed similar banding patterns to that of the mother plant thus demonstrating the homogeneity of the micropropagated plants. A comparative phytochemical analysis among the mother and the micropropagated plants showed a higher yield of secondary metabolites. The regeneration protocol developed in this study provides a basis for ex-situ germplasm conservation and also harnesses the various secondary metabolite compounds of medicinal importance present in D. nobile. PMID:25606433

  10. Genetic stability and phytochemical analysis of the in vitro regenerated plants of Dendrobium nobile Lindl., an endangered medicinal orchid.

    PubMed

    Bhattacharyya, Paromik; Kumaria, Suman; Diengdoh, Reemavareen; Tandon, Pramod

    2014-12-01

    An efficient genetically stable regeneration protocol with increased phytochemical production has been established for Dendrobium nobile, a highly prized orchid for its economic and medicinal importance. Protocorm like bodies (PLBs) were induced from the pseudostem segments using thidiazuron (TDZ; 1.5 mg/l), by-passing the conventional auxin-cytokinin complement approach for plant regeneration. Although, PLB induction was observed at higher concentrations of TDZ, plantlet regeneration from those PLBs was affected adversely. The best rooting (5.41 roots/shoot) was achieved in MS medium with 1.5 mg/l TDZ and 0.25% activated charcoal. Plantlets were successfully transferred to a greenhouse with a survival rate of 84.3%, exhibiting normal development. Genetic stability of the regenerated plants was investigated using randomly amplified polymorphic DNA (RAPD) and start codon targeted (SCoT) polymorphism markers which detected 97% of genetic fidelity among the regenerants. The PIC values of RAPD and SCoT primers were recorded to be 0.92 and 0.76 and their Rp values ranged between 3.66 and 10, and 4 and 12 respectively. The amplification products of the regenerated plants showed similar banding patterns to that of the mother plant thus demonstrating the homogeneity of the micropropagated plants. A comparative phytochemical analysis among the mother and the micropropagated plants showed a higher yield of secondary metabolites. The regeneration protocol developed in this study provides a basis for ex-situ germplasm conservation and also harnesses the various secondary metabolite compounds of medicinal importance present in D. nobile. PMID:25606433

  11. First Report of Plant Regeneration via Somatic Embryogenesis from Shoot Apex-derived Callus of Hedychium muluense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants were successfully regenerated via somatic embryogenesis from shoot apex-derived callus of Hedychium muluense R.M. Smith, an important monocotyledonous ornamental ginger plant. Callus was induced on a modified Murashige and Skoog (MS) medium supplemented with 9.05 µM 2-4, D and 4.6µM kinetin. ...

  12. Hydrochloric acid method of beneficiating magnesite using a pilot plant

    SciTech Connect

    Sertin, V.A.; Galkin, Y.M.; Gemusova, I.B.; Glezer, E.B.; Khaltyurin, V.A.; Kislitsyn, V.I.; Rodde, T.V.; Simonov, K.V.; Vetlugina, N.A.; Yurlova, L.N.; Zakutinskii, V.L.

    1985-07-01

    One feature of the HCl treatment of magnesite is the possibility of using the main mass of HCl in a closed cycle. Regeneration of the HCl takes place during the thermal hydrolysis of the purified solution of magnesium chloride. In accordance with the plan drawn up by the Eastern Institute of Refractories and the Ukranian Institute of Chemistry, a pilot plant has been built at the Magnesite Combine; this has been mastered and is used for the hydrochloric acid treatment of magnesite; the annual productivity of the equipment is 400 tons. Some features of the process of dissolution of natural and caustic magnesite in HCL and the sintering of the beneficiated product have been considered elsewhere. This paper pays particular attention to the apparatus-process character and considers in more detail the hydrolysis of magnesium chloride.

  13. Retinoic acid reduces solvent-induced neuropathy and promotes neural regeneration in mice.

    PubMed

    Palencia, Guadalupe; Hernández-Pedro, Norma; Saavedra-Perez, David; Peña-Curiel, Omar; Ortiz-Plata, Alma; Ordoñez, Graciela; Flores-Estrada, Diana; Sotelo, Julio; Arrieta, Oscar

    2014-08-01

    In humans, exposure to organic solvents (OS) is frequent in work activities or as a recreational inhalant, inducing severe neuropathy (secondary to demyelization of peripheral nerves). We have previously shown that all-trans retinoic acid (ATRA) increases local content of neural growth factor (NGF), improving peripheral neuropathy of diverse origins. In this study, we evaluated the effect of ATRA on OS-induced peripheral neuropathy in experimental mice. Two simultaneous experiments were performed. The first one aimed to evaluate ATRA for the prevention of damage induced by OS, the second to test ATRA as an OS-induced neuropathy treatment. Nociceptive threshold latency and NGF concentration in serum and in peripheral nerves were determined. Morphological changes and evidence of sciatic nerve regeneration were evaluated. Mice exposed to OS developed neuropathy and axonal degeneration. ATRA diminished the effects of OS inhalation on sensorial changes and nerve morphology. Treatment with ATRA reversed sensorial and nerve morphological changes of OS-induced neuropathy, and this was associated with increased contents of NGF. Similar to previous experiences on diabetic and toxic neuropathy, ATRA reduced and partially reversed the peripheral neuropathy caused by OS exposure. These favorable effects apparently are due to local production of NGF induced by neural regeneration in response to the administration of retinoic acid. PMID:24647975

  14. Improved regeneration potential of fibroblasts using ascorbic acid-blended nanofibrous scaffolds.

    PubMed

    Sridhar, Sreepathy; Venugopal, Jayarama Reddy; Ramakrishna, Seeram

    2015-11-01

    Two-dimensional scaffolds, three-dimensional scaffolds, and dermal substitutes are extensively used for biomedical applications in skin tissue regeneration. Not much explored synthetic polymers, like poly(l-lactic acid)-co-poly-(ε-caprolactone) (PLACL), natural polymers, like silk fibroin (SF), and active inducing agents, such as ascorbic acid (AA) and tetracycline hydrochloride (TCH), represent a favorable matrix for fabricating dermal substitutes to engineer artificial skin for wound repair. The profligate nature of residing skin cells near the wound site is a paramount to survival and also regulating stem cells and other cellular networks and mechanical forces. PLACL/SF/TCH/AA nanofibrous scaffolds were fabricated by electrospinning and characterized for fiber morphology, membrane porosity, wettability, and significant subchains using Fourier transform infrared spectroscopy for culturing human-derived dermal fibroblasts. The PLACL, PLACL/SF, PLACL/SF/TCH, and PLACL/SF/TCH/AA scaffolds obtained diameters between 250 and 340 nm. The secretion of collagen by the laboratory-grown fibroblasts over the AA-blended scaffolds was found to be significantly higher compared with that of other scaffolds. The obtained results positively prove that introduction of naturally secreting compounds (AA) by the cells into the nanofibrous scaffolds will favor cell's microenvironment and eventually leads to complete tissue regeneration. PMID:25903719

  15. Uptake and utilization of dissolved free amino acids by the brittlestar Microphiopholis gracillima (Say, 1852) (Echinodermata: Ophiuroidea) during disc regeneration

    SciTech Connect

    Clements, L.A.J.

    1988-01-01

    Dissolved organic material (DOM) may be especially important to marine organisms unable to feed due to lack of a digestive system, injury or autotomy. Disc autotomy by the brittlestar Microphiopholis gracillima includes loss of the gut and gonads, and precludes ingestion of particulate food by the animal until gut regeneration is complete. The influence of DOM on the rate of disc regeneration by autotomized M. gracillima was tested by incubating animals in artificial seawater containing different concentrations of amino acids. Rates of uptake of amino acids and excretion of amino acids, ammonia and urea by intact and regenerating M. gracillima individuals were quantified using high performance liquid chromatography. Uptake and catabolism of leucine and glycine were examined using radioisotopic techniques. Both intact and regenerating M. gracillima increased their uptake of {sup 14}C-glycine with starvation, but rates of uptake were higher for intact animals. Catabolism of leucine and glycine, as evidenced by release of labeled CO{sub 2}, was highest among intact animals indicating that the amino acids were being used as energy sources during starvation. However, regenerating animals catabolized less than 2% of the labeled glycine acquired from seawater.

  16. Biotechnological applications in in vitro plant regeneration studies of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

    PubMed

    Kumar, Pankaj; Srivastava, Dinesh Kumar

    2016-04-01

    Biotechnology holds promise for genetic improvement of important vegetable crops. Broccoli (Brassica oleracea L. var. italica) is an important vegetable crop of the family Brassicaceae. However, various biotic and abiotic stresses cause enormous crop yield losses during commercial cultivation of broccoli. Establishment of a reliable, reproducible and efficient in vitro plant regeneration system with cell and tissue culture is a vital prerequisite for biotechnological application of crop improvement programme. An in vitro plant regeneration technique refers to culturing, cell division, cell multiplication, de-differentiation and differentiation of cells, protoplasts, tissues and organs on defined liquid/solid medium under aseptic and controlled environment. Recent progress in the field of plant tissue culture has made this area one of the most dynamic and promising in experimental biology. There are many published reports on in vitro plant regeneration studies in broccoli including direct organogenesis, indirect organogenesis and somatic embryogenesis. This review summarizes those plant regeneration studies in broccoli that could be helpful in drawing the attention of the researchers and scientists to work on it to produce healthy, biotic and abiotic stress resistant plant material and to carry out genetic transformation studies for the production of transgenic plants. PMID:26721234

  17. Process of regenerating spent HF-HNO sub 3 pickle acid containing (ZrF sub 6 )-2

    SciTech Connect

    Walker, R.G.

    1992-01-21

    This patent describes a process for regenerating spent HF-HNO{sub 3} pickle acid containing (ZrF{sub 6}){sup {minus}2}. It comprises NaNO{sub 3} to a spent HF-HNO{sub 3} pickle acid containing (ZrF{sub 6}){sup {minus}2} to precipitate Na{sub 2}ZrF{sub 6}; and separating the HF-HNO{sub 3} pickle acid from the Na{sub 2}ZrF{sub 6} precipitate.

  18. Exploratory design study on reactor configurations for carbon dioxide capture from conventional power plants employing regenerable solid sorbents

    SciTech Connect

    Yang, W.C.; Hoffman, J.

    2009-01-15

    Preliminary commercial designs were carried out for a fluidized bed as a CO{sub 2} adsorber and a moving bed as a CO{sub 2} regenerator. Reverse engineering methodology was employed on the basis of a commercial 500 MW supercritical PC power plant whereby the boundaries required for a particular reactor design and configuration could be set. Employing the proposed moving bed for regenerator is, however, not promising because of poor heat transfer, evolution of CO{sub 2} during regeneration, and high pressure drop when small particles are used. If regeneration kinetics is as slow as reported in tens of minutes, the bed height can be quite high and the reactor can be quite costly. In its place, a so-called assisted self-fluidization bed with embedded heat transfer surface was proposed. Theoretically, there is no reason why the fluidized bed cannot be successfully designed and operated both as an adsorber and a regenerator under proper adsorption and regeneration kinetics. Recent publications, where fluidized beds, circulating fluidized beds, or a combination of them were employed both as an adsorber and a regenerator, were cited. Staging may not be necessary employing the fluidized bed technology because of the capability to control reaction temperature at the optimum operating temperature through embedded heat transfer surface in the fluidized beds. Even if the staging is necessary, the implementation of staging in fluidized beds at ambient pressure and moderate temperature is relatively easy and with minimum cost penalty. Example designs are presented.

  19. Plant regeneration of Korean wild ginseng (Panax ginseng Meyer) mutant lines induced by γ-irradiation (60Co) of adventitious roots

    PubMed Central

    Zhang, Jun-Ying; Sun, Hyeon-Jin; Song, In-Ja; Bae, Tae-Woong; Kang, Hong-Gyu; Ko, Suk-Min; Kwon, Yong-Ik; Kim, Il-Woung; Lee, Jaechun; Park, Shin-Young; Lim, Pyung-Ok; Kim, Yong Hwan; Lee, Hyo-Yeon

    2014-01-01

    An efficient in vitro protocol has been established for somatic embryogenesis and plantlet conversion of Korean wild ginseng (Panax ginseng Meyer). Wild-type and mutant adventitious roots derived from the ginseng produced calluses on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid and 0.3 mg/L kinetin; 53.3% of the explants formed callus. Embryogenic callus proliferation and somatic embryo induction occurred on MS medium containing 0.5 mg/L 2,4-dichlorophenoxyacetic acid. The induced somatic embryos further developed to maturity on MS medium with 5 mg/L gibberellic acid, and 85% of them germinated. The germinated embryos were developed to shoots and elongated on MS medium with 5 mg/L gibberellic acid. The shoots developed into plants with well-developed taproots on one-third strength Schenk and Hildebrandt basal medium supplemented with 0.25 mg/L 1-naphthaleneacetic acid. When the plants were transferred to soil, about 30% of the regenerated plants developed into normal plants. PMID:25378998

  20. Effect of histone deacetylase inhibitors trichostatin A and valproic acid on hair cell regeneration in zebrafish lateral line neuromasts

    PubMed Central

    He, Yingzi; Cai, Chengfu; Tang, Dongmei; Sun, Shan; Li, Huawei

    2014-01-01

    In humans, auditory hair cells are not replaced when injured. Thus, cochlear hair cell loss causes progressive and permanent hearing loss. Conversely, non-mammalian vertebrates are capable of regenerating lost sensory hair cells. The zebrafish lateral line has numerous qualities that make it well-suited for studying hair cell development and regeneration. Histone deacetylase (HDAC) activity has been shown to have an important role in regenerative processes in vertebrates, but its function in hair cell regeneration in vivo is not fully understood. Here, we have examined the role of HDAC activity in hair cell regeneration in the zebrafish lateral line. We eliminated lateral line hair cells of 5-day post-fertilization larvae using neomycin and then treated the larvae with HDAC inhibitors. To assess hair cell regeneration, we used 5-bromo-2-deoxyuridine (BrdU) incorporation in zebrafish larvae to label mitotic cells after hair cell loss. We found that pharmacological inhibition of HDACs using trichostatin A (TSA) or valproic acid (VPA) increased histone acetylation in the regenerated neuromasts following neomycin-induced damage. We also showed that treatment with TSA or VPA decreased the number of supporting cells and regenerated hair cells in response to hair cell damage. Additionally, BrdU immunostaining and western blot analysis showed that TSA or VPA treatment caused a significant decrease in the percentage of S-phase cells and induced p21Cip1 and p27Kip1 expression, both of which are likely to explain the decrease in the amount of newly regenerated hair cells in treated embryos. Finally, we showed that HDAC inhibitors induced no observable cell death in neuromasts as measured by cleaved caspase-3 immunohistochemistry and western blot analysis. Taken together, our results demonstrate that HDAC activity has an important role in the regeneration of hair cells in the lateral line. PMID:25431550

  1. Plant regeneration and cellular behaviour studies in Celosia cristata grown in vivo and in vitro.

    PubMed

    Taha, Rosna Mat; Wafa, Sharifah Nurashikin

    2012-01-01

    Tissue culture studies of Celosia cristata were established from various explants and the effects of various hormones on morphogenesis of this species were examined. It was found that complete plant regeneration occurred at highest percentage on MS medium supplemented with 2.0 mg/L NAA and 1.5 mg/L BAP, with the best response showed by shoot explants. In vitro flowering was observed on MS basal medium after six weeks. The occurrence of somaclonal variation and changes in cellular behavior from in vivo and in vitro grown plants were investigated through cytological studies and image analysis. It was observed that Mitotic Index (MI), mean chromosome numbers, and mean nuclear to cell area ratio of in vitro root meristem cells were slightly higher compared to in vivo values. However, in vitro plants produced lower mean cell areas but higher nuclear areas when compared to in vivo plants. Thus, no occurrence of somaclonal variation was detected, and this was supported by morphological features of the in vitro plants. PMID:22593677

  2. Plant Regeneration and Cellular Behaviour Studies in Celosia cristata Grown In Vivo and In Vitro

    PubMed Central

    Taha, Rosna Mat; Wafa, Sharifah Nurashikin

    2012-01-01

    Tissue culture studies of Celosia cristata were established from various explants and the effects of various hormones on morphogenesis of this species were examined. It was found that complete plant regeneration occurred at highest percentage on MS medium supplemented with 2.0 mg/L NAA and 1.5 mg/L BAP, with the best response showed by shoot explants. In vitro flowering was observed on MS basal medium after six weeks. The occurrence of somaclonal variation and changes in cellular behavior from in vivo and in vitro grown plants were investigated through cytological studies and image analysis. It was observed that Mitotic Index (MI), mean chromosome numbers, and mean nuclear to cell area ratio of in vitro root meristem cells were slightly higher compared to in vivo values. However, in vitro plants produced lower mean cell areas but higher nuclear areas when compared to in vivo plants. Thus, no occurrence of somaclonal variation was detected, and this was supported by morphological features of the in vitro plants. PMID:22593677

  3. Seedling–herbivore interactions: insights into plant defence and regeneration patterns

    PubMed Central

    Barton, Kasey E.; Hanley, Mick E.

    2013-01-01

    Background Herbivores have the power to shape plant evolutionary trajectories, influence the structure and function of vegetation, devastate entire crops, or halt the spread of invasive weeds, and as a consequence, research into plant–herbivore interactions is pivotal to our understanding of plant ecology and evolution. However, the causes and consequences of seedling herbivory have received remarkably little attention, despite the fact that plants tend to be most susceptible to herbivory during establishment, and this damage can alter community composition and structure. Scope In this Viewpoint article we review why herbivory during early plant ontogeny is important and in so doing introduce an Annals of Botany Special Issue that draws together the latest work on the topic. In a synthesis of the existing literature and a collection of new studies, we examine several linked issues. These include the development and expression of seedling defences and patterns of selection by herbivores, and how seedling selection affects plant establishment and community structure. We then examine how disruption of the seedling–herbivore interaction might affect normal patterns of plant community establishment and discuss how an understanding of patterns of seedling herbivory can aid our attempts to restore semi-natural vegetation. We finish by outlining a number of areas where more research is required. These include a need for a deeper consideration of how endogenous and exogenous factors determine investment in seedling defence, particularly for the very youngest plants, and a better understanding of the phylogenetic and biogeographical patterns of seedling defence. There is also much still be to be done on the mechanisms of seedling selection by herbivores, particularly with respect to the possible involvement of volatile cues. These inter-related issues together inform our understanding of how seedling herbivory affects plant regeneration at a time when anthropogenic

  4. Plant regeneration from cultured cell-derived protoplasts of Pelargonium aridum, P. x hortorum and P. peltatum.

    PubMed

    Yarrow, S A; Cocking, E C; Power, J B

    1987-04-01

    Cultured protoplasts from cell suspensions of Pelargonium aridum, P.x hortorum and P. peltatum divided and formed callus. On agar-solidified regenerative medium, such protoplast-derived calli (p-calli) underwent plant regeneration at frequencies approaching 100% for P. aridum and 10% for P.x hortorum. Under similar conditions shoot primordia arose in 5% of P. peltatum p-calli, but these never developed into normal shoots. However, following a liquid-shake culture regime, whole plants were induced in 20% of P. peltatum p-calli. This approach also improved regeneration of P.x hortorum to 60%. PMID:24248487

  5. Activated carbon cleanup of the acid gas feed to Claus sulfur plants

    SciTech Connect

    Harruff, L.G.; Bushkuhl, S.J.

    1996-12-31

    This paper presents the details of a recently developed novel process using activated carbon to remove hydrocarbon contaminants from the acid gas feed to Claus sulfur recovery units. Heavy hydrocarbons, particularly benzene, toluene and xylene (BTX) have been linked to coke formation and catalyst deactivation in Claus converters. This deactivation results in reduced sulfur recovery and increased sulfur emissions from these plants. This effect is especially evident in split flow Claus plants which bypass some of the acid gas feed stream around the initial combustion step because of a low hydrogen sulfide concentration. This new clean-up process was proven to be capable of removing 95% of the BTX and other C{sub 6}{sup +} hydrocarbons from acid gas over a wide range of actual plant conditions. Following the adsorption step, the activated carbon was easily regenerated using low pressure steam. A post regeneration drying step using plant fuel gas also proved beneficial. This technology was extensively pilot tested in Saudi Aramco`s facilities in Saudi Arabia. Full scale commercial units are planned for two plants in the near future with the first coming on-line in 1997. The process described here represents the first application of activated carbon in this service, and a patent has been applied for. The paper will discuss the pilot plant results and the issues involved in scale-up to commercial size.

  6. Role of amidation in bile acid effect on DNA synthesis by regenerating mouse liver.

    PubMed

    Barbero, E R; Herrera, M C; Monte, M J; Serrano, M A; Marin, J J

    1995-06-01

    Effect of bile acids on DNA synthesis by the regenerating liver was investigated in mice in vivo after partial hepatectomy (PH). Radioactivity incorporation into DNA after [14C]thymidine intraperitoneal administration peaked at 48 h after PH. At this time a significant taurocholate-induced dose-dependent reduction in DNA synthesis without changes in total liver radioactivity content was found (half-maximal effect at approximately 0.1 mumol/g body wt). Effect of taurocholate (0.5 mumol/g body wt) was mimicked by chocolate, ursodeoxycholate, deoxycholate, dehydrocholate, tauroursodeoxycholate, taurochenodeoxycholate, and taurodeoxycholate. In contrast, chenodeoxycholate, glycocholate, glycochenodeoxycholate, glycoursodeoxycholate, glycodeoxycholate, 5 beta-cholestane, bromosulfophthalein, and free taurine lacked this effect. No relationship between hydrophobic-hydrophilic balance and inhibitory effect was observed. Analysis by high-performance liquid chromatography indicated that inhibition of thymidine incorporation into DNA was not accompanied by an accumulation of phosphorylated DNA precursors in the liver but rather by a parallel increase in nucleotide catabolism. Bile acid-induced modifications in DNA synthesis were observed in vivo even in the absence of changes in toxicity tests, which suggests that the inhibitory effect shared by most unconjugated and tauroconjugated bile acids but not by glycoconjugated bile acids should be accounted for by mechanisms other than nonselective liver cell injury. PMID:7611405

  7. Effect of acid hydrolysis on regenerated kenaf core membrane produced using aqueous alkaline-urea systems.

    PubMed

    Padzil, Farah Nadia Mohammad; Zakaria, Sarani; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Kaco, Hatika; Gan, Sinyee; Ng, Peivun

    2015-06-25

    Bleached kenaf core pulps (BKC) were hydrolyzed in H2SO4 (0.5M) at different time (0min to 90min) at room temperature. After the hydrolysis process, the viscosity average molecular weight (Mŋ) for BKC sample has reduced from 14.5×10(4) to 2.55×10(4). The hydrolyzed BKC was then dissolved in NaOH:urea:water and in LiOH:urea:water mixed solvent at the ratio of 7:12:81 and 4.6:15:80.4, respectively. The increased in hydrolysis time has decreased Mŋ of cellulose leading to easy dissolution process. Higher porosity and transparency with lower crystallinity index (CrI) of regenerated membrane produced can be achieved as the Mŋ reduced. The properties of membrane were observed through FESEM, UV-vis spectrophotometer and XRD. This study has proven that acid hydrolysis has reduced the Mŋ of cellulose, thus, enhanced the properties of regenerated membrane produced with assisted by alkaline/urea system. PMID:25839807

  8. Once and again: retinoic acid signaling in the developing and regenerating olfactory pathway.

    PubMed

    Rawson, N E; LaMantia, A-S

    2006-06-01

    Retinoic acid (RA), a member of the steroid/thyroid superfamily of signaling molecules, is an essential regulator of morphogenesis, differentiation, and regeneration in the mammalian olfactory pathway. RA-mediated teratogenesis dramatically alters olfactory pathway development, presumably by disrupting retinoid-mediated inductive signaling that influences initial olfactory epithelium (OE) and bulb (OB) morphogenesis. Subsequently, RA modulates the genesis, growth, or stability of subsets of OE cells and OB interneurons. RA receptors, cofactors, and synthetic enzymes are expressed in the OE, OB, and anterior subventricular zone (SVZ), the site of neural precursors that generate new OB interneurons throughout adulthood. Their expression apparently accommodates RA signaling in OE cells, OB interneurons, and slowly dividing SVZ neural precursors. Deficiency of vitamin A, the dietary metabolic RA precursor, leads to cytological changes in the OE, as well as olfactory sensory deficits. Vitamin A therapy in animals with olfactory system damage can accelerate functional recovery. RA-related pathology as well as its potential therapeutic activity may reflect endogenous retinoid regulation of neuronal differentiation, stability, or regeneration in the olfactory pathway from embryogenesis through adulthood. These influences may be in register with retinoid effects on immune responses, metabolism, and modulation of food intake. PMID:16688760

  9. Effects of high-frequency understorey fires on woody plant regeneration in southeastern Amazonian forests

    PubMed Central

    Balch, Jennifer K.; Massad, Tara J.; Brando, Paulo M.; Nepstad, Daniel C.; Curran, Lisa M.

    2013-01-01

    Anthropogenic understorey fires affect large areas of tropical forest, yet their effects on woody plant regeneration post-fire remain poorly understood. We examined the effects of repeated experimental fires on woody stem (less than 1 cm at base) mortality, recruitment, species diversity, community similarity and regeneration mode (seed versus sprout) in Mato Grosso, Brazil. From 2004 to 2010, forest plots (50 ha) were burned twice (B2) or five times (B5), and compared with an unburned control (B0). Stem density recovered within a year after the first burn (initial density: 12.4–13.2 stems m−2), but after 6 years, increased mortality and decreased regeneration—primarily of seedlings—led to a 63 per cent and 85 per cent reduction in stem density in B2 and B5, respectively. Seedlings and sprouts across plots in 2010 displayed remarkable community similarity owing to shared abundant species. Although the dominant surviving species were similar across plots, a major increase in sprouting occurred—almost three- and fourfold greater in B2 and B5 than in B0. In B5, 29 species disappeared and were replaced by 11 new species often present along fragmented forest edges. By 2010, the annual burn regime created substantial divergence between the seedling community and the initial adult tree community (greater than or equal to 20 cm dbh). Increased droughts and continued anthropogenic ignitions associated with frontier land uses may promote high-frequency fire regimes that may substantially alter regeneration and therefore successional processes. PMID:23610167

  10. Tandem dissolution of UO3 in amide-based acidic ionic liquid and in situ electrodeposition of UO2 with regeneration of the ionic liquid: a closed cycle.

    PubMed

    Wanigasekara, Eranda; Freiderich, John W; Sun, Xiao-Guang; Meisner, Roberta A; Luo, Huimin; Delmau, Lætitia H; Dai, Sheng; Moyer, Bruce A

    2016-06-21

    A closed cycle is demonstrated for the tandem dissolution and electroreduction of UO3 to UO2 with regeneration of the acidic ionic liquid. The dissolution is achieved by use of the acidic ionic liquid [DMAH][NTf2] in [EMIM][NTf2] serving as the diluent. A sequential dissolution, electroreduction, and regeneration cycle is presented. PMID:27255672

  11. Area Expansivity Moduli of Regenerating Plant Protoplast Cell Walls Exposed to Shear Flows

    NASA Astrophysics Data System (ADS)

    Fujimura, Yuu; Iino, Masaaki; Watanabe, Ugai

    2005-05-01

    To control the elasticity of the plant cell wall, protoplasts isolated from cultured Catharanthus roseus cells were regenerated in shear flows of 115 s-1 (high shear) and 19.2 s-1 (low shear, as a control). The surface area expansivity modulus and the surface breaking strength of these regenerating protoplasts were measured by a micropipette aspiration technique. Cell wall synthesis was also measured using a cell wall-specific fluorescent dye. High shear exposure for 3 h doubled both the surface area modulus and breaking strength observed under low shear, significantly decreased cell wall synthesis, and roughly quadrupled the moduli of the cell wall. Based on the cell wall synthesis data, we estimated the three-dimensional modulus of the cell wall to be 4.1± 1.2 GPa for the high shear, and 0.35± 0.2 GPa for the low shear condition, using the surface area expansivity modulus divided by the cell wall thickness, which is identical with the Young’s modulus divided by 2(1-σ), where σ is Poisson's ratio. We concluded that high shear exposure considerably strengthens the newly synthesized cell wall.

  12. Development of plant regeneration and transformation protocols for the desiccation-sensitive weeping lovegrass Eragrostis curvula.

    PubMed

    Ncanana, Sandile; Brandt, Wolf; Lindsey, George; Farrant, Jill

    2005-08-01

    A tissue culture protocol, suitable for transformation, was established for the pasture grass Eragrostis curvula. Callus was generated in the dark from leaf and seed tissues on a medium comprising MS salts supplemented with 2 mg/l 2,4-D, 0.01 mg/l BAP and 2% sucrose. Plant regeneration occurred via organogenesis on the same medium with 6% and 3% sucrose for shoot and root formation, respectively. Optimal regeneration (50 plantlets per callus) occurred when light of 45 micromol/m2 per s was used. The yeast Saccharomyces cerevisiae Hsp12 gene was cloned into the Sac1 of the pCAMBIAUbeeQ vector and callus was transformed by biolistic bombardment. Best transformation (30%) occurred when the target tissue was bombarded twice at a distance of 70 mm using a bombardment pressure of 9,100 kPa. Although successful transformation and transcription of the Hsp12 gene occurred, no Hsp12 protein was found present in tissue extracts of transformed grass. PMID:15776238

  13. Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants.

    PubMed

    Chen, M H; Wang, P J; Maeda, E

    1987-10-01

    The regeneration potential of shoot tip, stem, leaf, cotyledon and root explants of two papaya cultivars (Carica papaya cv. 'Solo' and cv. 'Sunrise') were studed. Callus induction of these two cultivars of papaya showed that the shoot tips and stems are most suitable for forming callus, while leaves, cotyledons and roots are comparatively difficult to induce callus. Callus induction also varied with the varities. Somatic embryogenesis was obtained from 3-month-old root cultures. A medium containing half strength of MS inorganic salts, 160 mg/l adenine sulfate, 1.0 mg/1 NAA, 0.5 mg/1 kinetin and 1.0 mg/1 GA3 was optimal for embryogenesis. The callus maintained high regenerative capacity after two years of culture on this medium. Plants derived from somatic embryos were obtained under green-house conditions. PMID:24248842

  14. 2-Hydroxy Acids in Plant Metabolism

    PubMed Central

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

    2015-01-01

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

  15. Agrobacterium-mediated genetic transformation and plant regeneration of the hardwood tree species Fraxinus profunda.

    PubMed

    Stevens, Micah E; Pijut, Paula M

    2014-06-01

    This transformation and regeneration protocol provides an integral framework for the genetic improvement of Fraxinus profunda (pumpkin ash) for future development of plants resistant to the emerald ash borer. Using mature hypocotyls as the initial explants, an Agrobacterium tumefaciens-mediated genetic transformation system was successfully developed for pumpkin ash (Fraxinus profunda). This transformation protocol is an invaluable tool to combat the highly aggressive, non-native emerald ash borer (EAB), which has the potential to eliminate native Fraxinus spp. from the natural landscape. Hypocotyls were successfully transformed with Agrobacterium strain EHA105 harboring the pq35GR vector, containing an enhanced green fluorescent protein (EGFP) as well as a fusion gene between neomycin phosphotransferase (nptII) and gusA. Hypocotyls were cultured for 7 days on Murashige and Skoog (MS) medium with 22.2 μM 6-benzyladenine (BA), 4.5 μM thidiazuron (TDZ), 50 mg L(-1) adenine hemisulfate (AS), and 10 % coconut water (CW) prior to transformation. Hypocotyls were transformed using 90 s sonication plus 10 min vacuum infiltration after Agrobacterium was exposed to 100 μM acetosyringone for 1 h. Adventitious shoots were regenerated on MS medium with 22.2 μM BA, 4.5 μM TDZ, 50 mg L(-1) AS, 10 % CW, 400 mg L(-1) timentin, and 20 mg L(-1) kanamycin. Timentin at 400 and 20 mg L(-1) kanamycin were most effective at controlling Agrobacterium growth and selecting for transformed cells, respectively. The presence of nptII, GUS (β-glucuronidase), and EGFP in transformed plants was confirmed using polymerase chain reaction (PCR), while the expression of EGFP was also confirmed through fluorescent microscopy and reverse transcription-PCR. This transformation protocol provides an integral foundation for future genetic modifications of F. profunda to provide resistance to EAB. PMID:24493252

  16. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

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

    2005-08-30

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

  17. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

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

    2011-08-23

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

  18. Protoplast isolation and plant regeneration of guava (Psidium guajava L.) using experiments in mixture-amount design

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A protocol was established for plant regeneration from leaf protoplasts of guava (Psidium guajava L.) using mixture-amount (concentration) experiments. A protoplast yield of 3.7 × 106 (viability > 90 percent) was obtained when 1 g leaf strips were digested in a solution of approximately 0.75 M osmot...

  19. A high throughput transformation system allows the regeneration of marker-free plum plants (Prunus domestica L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high-throughput transformation system previously developed in our laboratory was used for the regeneration of transgenic plum plants without the use of antibiotic selection. The system was first tested with two experimental constructs, pGA482GGi and pCAMBIAgfp94(35S), that contain selective marke...

  20. Salicylic Acid Improved In Viro Meristem Regeneration and Salt Tolerance in Two Hibiscus Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salicylic acid (SA) has been reported to induce abiotic stress, including salt tolerance in plants. The objective of this study was to determine whether application of various exogenous SA concentrations to in vitro grown meristem shoots could induce salt tolerance in two Hibiscus species. The effec...

  1. Direct embryogenesis and green plant regeneration from isolated microspores of hexaploid triticale (x Triticosecale Wittmack) cv. Bogo.

    PubMed

    Oleszczuk, S; Sowa, S; Zimny, J

    2004-07-01

    The use of doubled haploids improves the efficiency of cultivar development in many crops and can be helpful in genetic and molecular studies. The major problem with this approach is the low efficiency of green plant regeneration. We describe here an efficient method for inducing embryos and regenerating green plants directly from isolated microspores of hexaploid triticale (x Triticosecale Wittmack) cv. Bogo. The absence of growth regulators in the induction medium was the most effective condition for the formation of embryo-like structures. The highest induction rates were observed at microspore densities of 1.5x10(5) microspores and 2x10(5) microspores per milliliter. Such cultures produced an average of 54.9 green plants per single donor spike. The frequency of albino plants ranged from 9.3% to 22.9%. Among the green progeny tested, 30.8% were spontaneously doubled haploids. PMID:15108018

  2. Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost

    PubMed Central

    Yashina, Svetlana; Gubin, Stanislav; Maksimovich, Stanislav; Yashina, Alexandra; Gakhova, Edith; Gilichinsky, David

    2012-01-01

    Whole, fertile plants of Silene stenophylla Ledeb. (Caryophyllaceae) have been uniquely regenerated from maternal, immature fruit tissue of Late Pleistocene age using in vitro tissue culture and clonal micropropagation. The fruits were excavated in northeastern Siberia from fossil squirrel burrows buried at a depth of 38 m in undisturbed and never thawed Late Pleistocene permafrost sediments with a temperature of −7 °C. Accelerator mass spectrometry (AMS) radiocarbon dating showed fruits to be 31,800 ± 300 y old. The total γ-radiation dose accumulated by the fruits during this time was calculated as 0.07 kGy; this is the maximal reported dose after which tissues remain viable and seeds still germinate. Regenerated plants were brought to flowering and fruiting and they set viable seeds. At present, plants of S. stenophylla are the most ancient, viable, multicellular, living organisms. Morphophysiological studies comparing regenerated and extant plants obtained from modern seeds of the same species in the same region revealed that they were distinct phenotypes of S. stenophylla. The first generation cultivated from seeds obtained from regenerated plants progressed through all developmental stages and had the same morphological features as parent plants. The investigation showed high cryoresistance of plant placental tissue in permafrost. This natural cryopreservation of plant tissue over many thousands of years demonstrates a role for permafrost as a depository for an ancient gene pool, i.e., preexisting life, which hypothetically has long since vanished from the earth's surface, a potential source of ancient germplasm, and a laboratory for the study of rates of microevolution. PMID:22355102

  3. Molecular Mechanisms of Ursodeoxycholic Acid Toxicity & Side Effects: Ursodeoxycholic Acid Freezes Regeneration & Induces Hibernation Mode

    PubMed Central

    Kotb, Magd A.

    2012-01-01

    Ursodeoxycholic acid (UDCA) is a steroid bile acid approved for primary biliary cirrhosis (PBC). UDCA is reported to have “hepato-protective properties”. Yet, UDCA has “unanticipated” toxicity, pronounced by more than double number of deaths, and eligibility for liver transplantation compared to the control group in 28 mg/kg/day in primary sclerosing cholangitis, necessitating trial halt in North America. UDCA is associated with increase in hepatocellular carcinoma in PBC especially when it fails to achieve biochemical response (10 and 15 years incidence of 9% and 20% respectively). “Unanticipated” UDCA toxicity includes hepatitis, pruritus, cholangitis, ascites, vanishing bile duct syndrome, liver cell failure, death, severe watery diarrhea, pneumonia, dysuria, immune-suppression, mutagenic effects and withdrawal syndrome upon sudden halt. UDCA inhibits DNA repair, co-enzyme A, cyclic AMP, p53, phagocytosis, and inhibits induction of nitric oxide synthatase. It is genotoxic, exerts aneugenic activity, and arrests apoptosis even after cellular phosphatidylserine externalization. UDCA toxicity is related to its interference with drug detoxification, being hydrophilic and anti-apoptotic, has a long half-life, has transcriptional mutational abilities, down-regulates cellular functions, has a very narrow difference between the recommended (13 mg/kg/day) and toxic dose (28 mg/kg/day), and it typically transforms into lithocholic acid that induces DNA strand breakage, it is uniquely co-mutagenic, and promotes cell transformation. UDCA beyond PBC is unjustified. PMID:22942741

  4. Development of Efficient Plant Regeneration and Transformation System for Impatiens Using Agrobacterium tumefaciens and Multiple Bud Cultures as Explants

    PubMed Central

    2010-01-01

    Background Impatiens (Impatiens walleriana) is a top selling floriculture crop. The potential for genetic transformation of Impatiens to introduce novel flower colors or virus resistance has been limited by its general recalcitrance to tissue culture and transformation manipulations. We have established a regeneration and transformation system for Impatiens that provides new alternatives to genetic improvement of this crop. Results In a first step towards the development of transgenic INSV-resistant Impatiens, we developed an efficient plant regeneration system using hypocotyl segments containing cotyledonary nodes as explants. With this regeneration system, 80% of explants produced an average of 32.3 elongated shoots per initial explant plated, with up to 167 elongated shoots produced per explant. Rooting efficiency was high, and 100% of shoots produced roots within 12 days under optimal conditions, allowing plant regeneration within approximately 8 weeks. Using this regeneration system, we developed an efficient Agrobacterium-mediated Impatiens transformation method using in vitro multiple bud cultures as explants and a binary plasmid (pHB2892) bearing gfp and nptII genes. Transgenic Impatiens plants, with a frequency up to 58.9%, were obtained within 12 to 16 weeks from inoculation to transfer of transgenic plants to soil. Transgenic plants were confirmed by Southern blot, phenotypic assays and T1 segregation analysis. Transgene expression was observed in leaves, stems, roots, flowers, and fruit. The transgenic plants were fertile and phenotypically normal. Conclusion We report the development of a simple and efficient Agrobacterium-mediated transformation system for Impatiens. To the best of our knowledge, there have been no reports of Agrobacterium-mediated transformation of Impatiens with experimental evidence of stable integration of T-DNA and of Agrobacterium-mediated transformation method for plants using in vitro maintained multiple bud cultures as

  5. The Effects of Weak Combined Magnetic Field on Cell Wall Regeneration and Frequency of Plant Protoplasts Fusion

    NASA Astrophysics Data System (ADS)

    Nedukha, Olena

    The major purpose of these experiments was to investigate plant protoplast fusion frequency and regeneration of a cell wall by protoplasts at weak combined magnetic field (CMF) with the frequency resonance to the cyclotron frequency of Mg2+, Ca2+ and K+ ions. The protoplasts were isolated from Nicotiana lumbaginifolia and N. silvestris leaf mesophyll and from callus tissues (Nicotiana tabacum and Glycine max). The special extra apparatus with ferromagnetic shield was used for estimate of CMF with the frequency resonance to the cyclotron frequency of Mg2+, Ca2+ and K+ ions. The fusion of protoplasts is realized by using of parent protoplasts isolated from one plant species, as well as from various plant species. Control samples were situated near the apparatus with CMF. The laser confocal microscopy was used for study of cell wall regeneration by single and fused protoplasts. The cytochemical methods with DAPI and calcofluor dye were also applied as the detectors for protoplast fusion and regeneration of cell wall. We have been established that CMF with frequency adjusted to the cyclotron frequency Mg2+ ions have shown the most positive influence on regeneration of cell wall by protoplasts. CMF adjusted to the cyclotron frequency of K+ ions very weakly affected on the frequency of protoplast fusion. Largest frequency of protoplasts fusion is noted in the CMF adjusted to the cyclotron frequency of Ca2+ in comparison with the control samples.

  6. Salicylic acid-based poly(anhydride-ester) nerve guidance conduits: Impact of localized drug release on nerve regeneration.

    PubMed

    Lee, Yong S; Griffin, Jeremy; Masand, Shirley N; Shreiber, David I; Uhrich, Kathryn E

    2016-04-01

    Nerve guidance conduits (NGCs) can serve as physical scaffolds aligning and supporting regenerating cells while preventing scar tissue formation that often interferes with the regeneration process. Numerous studies have focused on functionalizing NGCs with neurotrophic factors, for example, to support nerve regeneration over longer gaps, but few directly incorporate therapeutic agents. Herein, we fabricated NGCs from a polyanhydride comprised of salicylic acid (SA), a nonsteroidal anti-inflammatory drug, then performed in vitro and in vivo assays. In vitro studies included cytotoxicity, anti-inflammatory response, and NGC porosity measurements. To prepare for implantation, type I collagen hydrogels were used as NGC luminal fillers to further enhance the axonal regeneration process. For the in vivo studies, SA-NGCs were implanted in femoral nerves of mice for 16 weeks and evaluated for functional recovery. The SA-based NGCs functioned as both a drug delivery vehicle capable of reducing inflammation and scar tissue formation because of SA release as well as a tissue scaffold that promotes peripheral nerve regeneration and functional recovery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 975-982, 2016. PMID:26691691

  7. The response of forest plant regeneration to temperature variation along a latitudinal gradient

    PubMed Central

    De Frenne, Pieter; Graae, Bente J.; Brunet, Jörg; Shevtsova, Anna; De Schrijver, An; Chabrerie, Olivier; Cousins, Sara A. O.; Decocq, Guillaume; Diekmann, Martin; Hermy, Martin; Heinken, Thilo; Kolb, Annette; Nilsson, Christer; Stanton, Sharon; Verheyen, Kris

    2012-01-01

    Background and Aims The response of forest herb regeneration from seed to temperature variations across latitudes was experimentally assessed in order to forecast the likely response of understorey community dynamics to climate warming. Methods Seeds of two characteristic forest plants (Anemone nemorosa and Milium effusum) were collected in natural populations along a latitudinal gradient from northern France to northern Sweden and exposed to three temperature regimes in growth chambers (first experiment). To test the importance of local adaptation, reciprocal transplants were also made of adult individuals that originated from the same populations in three common gardens located in southern, central and northern sites along the same gradient, and the resulting seeds were germinated (second experiment). Seedling establishment was quantified by measuring the timing and percentage of seedling emergence, and seedling biomass in both experiments. Key Results Spring warming increased emergence rates and seedling growth in the early-flowering forb A. nemorosa. Seedlings of the summer-flowering grass M. effusum originating from northern populations responded more strongly in terms of biomass growth to temperature than southern populations. The above-ground biomass of the seedlings of both species decreased with increasing latitude of origin, irrespective of whether seeds were collected from natural populations or from the common gardens. The emergence percentage decreased with increasing home-away distance in seeds from the transplant experiment, suggesting that the maternal plants were locally adapted. Conclusions Decreasing seedling emergence and growth were found from the centre to the northern edge of the distribution range for both species. Stronger responses to temperature variation in seedling growth of the grass M. effusum in the north may offer a way to cope with environmental change. The results further suggest that climate warming might differentially affect

  8. The regeneration of epidermal cells of Saintpaulia leaves as a new plant-tissue system for cellular radiation biology.

    PubMed

    Engels, F M; van der Laan, F M; Leenhouts, H P; Chadwick, K H

    1980-09-01

    Investigation of the nucleus of epidermal cells of the petioles of Saintpaulia leaves by cytofluorimetry revealed that all cells are in a non-cycling pre DNA synthesis phase. Cultivation of dissected leaves results in a synchronous regeneration process of a defined number of cells. Five days after onset of cultivation the cells reach the first mitosis. The nuclear development during the regeneration process is described. Irradiation of the leaves results in a directly visible inhibition of this regenerating capability which is used to quantify cell survival in a tissue. The data show that the radiation response has a similar shape to that of the survival of single cells in culture. This response can be observed before the first mitosis of the cells and its application as a new plant tissue system for cellular radiation research is discussed. PMID:7012060

  9. Doubled haploid production from Spanish onion (Allium cepa L.) germplasm: embryogenesis induction, plant regeneration and chromosome doubling

    PubMed Central

    Fayos, Oreto; Vallés, María P.; Garcés-Claver, Ana; Mallor, Cristina; Castillo, Ana M.

    2015-01-01

    The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2–3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09%) and Fuentes de Ebro the lowest (0.53%). These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%), whereas the lowest percentage was observed with glass tubes in the two protocols (20–23%). Different amiprofos-methyl (APM) treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 μM APM in liquid medium. However, the application of 25 μM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the four regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their gynogenesis

  10. [Plants regeneration from genetically transformed root and callus cultures of periwinkle Vinca minor L. and foxglove purple Digitalis purpurea L].

    PubMed

    Leshina, L G; Bulko, O V

    2014-01-01

    Plants regenerated from hairy roots and calluses of foxglove purple and periwinkle have been obtained. It was found that organogenesis in hairy root culture occurs spontaneously on hormone-free medium but with different efficiencies. The frequency of direct shoot formation from root cultures was up to 60% in Digitalis and 3.7% in Vinca. Addition of 1 mg/l BA, 0.1 mg/l NAA and 5% sucrose to B5 medium increased regenerative capacity of Vinca roots up to 19.1%. Regenerated plants showed morphological features typically seen in Ri-transgenic plants. They include growth and plagiotropism of the root system, increased shoot formation, changed leaf morphology and short internodes. PMID:25318175

  11. Tandem dissolution of UO 3 in amide-based acidic ionic liquid and in situ electrodeposition of UO 2 with regeneration of the ionic liquid: a closed cycle

    DOE PAGESBeta

    Wanigasekara, Eranda; Freiderich, John W.; Sun, Xiao-Guang; Meisner, Roberta A.; Luo, Huimin; Delmau, Lætitia H.; Dai, Sheng; Moyer, Bruce A.

    2016-05-19

    A closed cycle is demonstrated for the tandem dissolution and electroreduction of UO3 to UO2 with regeneration of the acidic ionic liquid. The dissolution is achieved by use of the acidic ionic liquid N,N-dimethylacetimidium bis(trifluoromethanesulfonimide) in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonimide) serving as the diluent. Bulk electrolysis performed at 1.0 V vs. Ag reference yields a dark brown-black uranium deposit (UO2) on the cathode. Anodic oxidation of water in the presence of dimethylacetamide regenerates the acidic ionic liquid. We have demonstrated the individual steps in the cycle together with a sequential dissolution, electroreduction, and regeneration cycle.

  12. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

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

    2001-01-01

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

  13. Effect of a peat humic acid on morphogenesis in leaf explants of Pyrus communis and Cydonia oblonga . Metabolomic analysis at an early stage of regeneration.

    PubMed

    Marino, Grazia; Righi, Valeria; Simoni, Andrea; Schenetti, Luisa; Mucci, Adele; Tugnoli, Vitaliano; Muzzi, Enrico; Francioso, Ornella

    2013-05-29

    Plant regeneration is a critical step in most in vitro breeding techniques. This paper studies the effects of a low-molecular-weight humic acid (HA) on morphogenesis from pear and quince leaf explants. Variable HA amounts [0 (control), 1, 5, 10, and 20 mg C L(-1)] were added to the regeneration media. A dose-response effect was observed in pear for root and shoot production; it was improved at HA 1 mg C L(-1) and considerably reduced at the highest amounts. HA was, instead, ineffective in quince. The (1)H HR-MAS NMR analyses of calli in the induction phase showed more evident metabolite (asparagine, alanine, and γ-aminobutyric acid) signals in quince than in pear. The assignment of overlapped signals in both genotypes was supported by the 2D NMR analyses. Spectroscopic characterization suggested also an enhancement of asparagine contents in morphogenic calli of pear with respect to the control and higher HA amount treatments. PMID:23627499

  14. Silica supported palladium nanoparticles for the decarboxylation of high-acid feedstocks: Design, deactivation and regeneration

    NASA Astrophysics Data System (ADS)

    Ping, Eric Wayne

    2011-12-01

    The major goals of this thesis were to (1) design and synthesize a supported catalyst with well-defined monodisperse palladium nanoparticles evenly distributed throughout an inorganic oxide substrate with tunable porosity characteristics, (2) demonstrate the catalytic activity of this material in the decarboxylation of long chain fatty acids and their derivatives to make diesel-length hydrocarbons, (3) elucidate the deactivation mechanism of supported palladium catalysts under decarboxylation conditions via post mortem catalyst characterization and develop a regeneration methodology thereupon, and (4) apply this catalytic system to a real low-value biofeedstock. Initial catalyst designs were based on the SBA-15 silica support, but in an effort to maximize loading and minimize mass transfer limitations, silica MCF was synthesized as catalyst support. Functionalization with various silane ligands yielded a surface that facilitated even distribution of palladium precursor salts throughout the catalyst particle, and, after reduction, monodisperse palladium nanoparticles approximately 2 nm in diameter. Complete characterization was performed on this Pd-MCF catalyst. The Pd-MCF catalyst showed high one-time activity in the decarboxylation of fatty acids to hydrocarbons in dodecane at 300°C. Hydrogen was found to be an unnecessary reactant in the absence of unsaturations, but was required in their presence---full hydrogenation of the double bonds occurs before any decarboxylation can take place. The Pd-MCF also exhibited good activity for alkyl esters and glycerol, providing a nice hypothetical description of a stepwise reaction pathway for catalytic decarboxylation of acids and their derivatives. As expected, the Pd-MCF catalyst experienced severe deactivation after only one use. Substantial effort was put into elucidating the nature of this deactivation via post mortem catalyst characterization. H2 chemisorption confirmed a loss of active surface area, but TEM and

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

    DOEpatents

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

    1995-07-04

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

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

    DOEpatents

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

    1995-01-01

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

  17. An efficient in vitro shoot regeneration from leaf petiolar explants and ex vitro rooting of Bixa orellana L.- A dye yielding plant.

    PubMed

    Mohammed, Arifullah; Chiruvella, Kishore K; Namsa, Nima D; Ghanta, Rama Gopal

    2015-07-01

    Bixa orellana L. (Bixaceae) is a multipurpose tree grown for the production of commercially important dyes. In the present study, an efficient, reproducible protocol was developed for direct plant regeneration from in vitro derived petiole explants of Bixa orellana L. Murashige and Skoog medium (MS) supplemented with 2-isopentenyl adenine (9.8 μM) and naphthalene acetic acid (10.7 μM) was found to be optimum for production of high frequency of shoot organogenesis. Subculturing of the shoots onto the fresh MS medium containing similar concentrations of 2-iP (9.8 μM) and NAA (10.7 μM) produced elongated shoots. Elongated shoots when placed onto MS medium supplemented with 1.7 μM indole-3-acetic acid and 14.7 μM 2-iP produced optimal rooting. Rooted plantlets were acclimatized and transplanted to the field successfully. Histological investigation revealed the origin of shoot primordia, from sub-epidermal cells of petiole explants. The regeneration protocol developed in this study can be useful for mass in vitro propagation and effective genetic transformation of commercially important edible dye yielding tree species. PMID:26261406

  18. Creation of highly aligned electrospun poly-L-lactic acid fibers for nerve regeneration applications

    NASA Astrophysics Data System (ADS)

    Wang, Han Bing; Mullins, Michael E.; Cregg, Jared M.; Hurtado, Andres; Oudega, Martin; Trombley, Matthew T.; Gilbert, Ryan J.

    2009-02-01

    Aligned, electrospun polymer fibers have shown considerable promise in directing regenerating axons in vitro and in vivo. However, in several studies, final electrospinning parameters are presented for producing aligned fiber scaffolds, and alignment where minimal fiber crossing occurs is not achieved. Highly aligned species are necessary for neural tissue engineering applications to ensure that axonal extension occurs through a regenerating environment efficiently. Axonal outgrowth on fibers that deviate from the natural axis of growth may delay axonal extension from one end of a scaffold to the other. Therefore, producing aligned fiber scaffolds with little fiber crossing is essential. In this study, the contributions of four electrospinning parameters (collection disk rotation speed, needle size, needle tip shape and syringe pump flow rate) were investigated thoroughly with the goal of finding parameters to obtain highly aligned electrospun fibers made from poly-L-lactic acid (PLLA). Using an 8 wt% PLLA solution in chloroform, a collection disk rotation speed of 1000 revolutions per minute (rpm), a 22 gauge, sharp-tip needle and a syringe pump rate of 2 ml h-1 produced highly aligned fiber (1.2-1.6 µm in diameter) scaffolds verified using a fast Fourier transform and a fiber alignment quantification technique. Additionally, the application of an insulating sheath around the needle tip improved the rate of fiber deposition (electrospinning efficiency). Optimized scaffolds were then evaluated in vitro using embryonic stage nine (E9) chick dorsal root ganglia (DRGs) and rat Schwann cells (SCs). To demonstrate the importance of creating highly aligned scaffolds to direct neurite outgrowth, scaffolds were created that contained crossing fibers. Neurites on these scaffolds were directed down the axis of the aligned fibers, but neurites also grew along the crossed fibers. At times, these crossed fibers even stopped further axonal extension. Highly aligned PLLA fibers

  19. AtTCTP2, an Arabidopsis thaliana homolog of Translationally Controlled Tumor Protein, enhances in vitro plant regeneration.

    PubMed

    Toscano-Morales, Roberto; Xoconostle-Cázares, Beatriz; Cabrera-Ponce, José L; Hinojosa-Moya, Jesús; Ruiz-Salas, Jorge L; Galván-Gordillo, Santiago V; Guevara-González, Ramón G; Ruiz-Medrano, Roberto

    2015-01-01

    The Translationally Controlled Tumor Protein (TCTP) is a central regulator of cell proliferation and differentiation in animals, and probably also in plants. Arabidopsis harbors two TCTP genes, AtTCTP1 (At3g16640), which is an important mitotic regulator, and AtTCTP2 (At3g05540), which is considered a pseudogene. Nevertheless, we have obtained evidence suggesting that this gene is functional. Indeed, a T-DNA insertion mutant, SALK_045146, displays a lethal phenotype during early rosette stage. Also, both the AtTCTP2 promoter and structural gene are functional, and heterozygous plants show delayed development. AtTCTP1 cannot compensate for the loss of AtTCTP2, since the accumulation levels of the AtTCTP1 transcript are even higher in heterozygous plants than in wild-type plants. Leaf explants transformed with Agrobacterium rhizogenes harboring AtTCTP2, but not AtTCTP1, led to whole plant regeneration with a high frequency. Insertion of a sequence present in AtTCTP1 but absent in AtTCTP2 demonstrates that it suppresses the capacity for plant regeneration; also, this phenomenon is enhanced by the presence of TCTP (AtTCTP1 or 2) in the nuclei of root cells. This confirms that AtTCTP2 is not a pseudogene and suggests the involvement of certain TCTP isoforms in vegetative reproduction in some plant species. PMID:26191065

  20. AtTCTP2, an Arabidopsis thaliana homolog of Translationally Controlled Tumor Protein, enhances in vitro plant regeneration

    PubMed Central

    Toscano-Morales, Roberto; Xoconostle-Cázares, Beatriz; Cabrera-Ponce, José L.; Hinojosa-Moya, Jesús; Ruiz-Salas, Jorge L.; Galván-Gordillo, Santiago V.; Guevara-González, Ramón G.; Ruiz-Medrano, Roberto

    2015-01-01

    The Translationally Controlled Tumor Protein (TCTP) is a central regulator of cell proliferation and differentiation in animals, and probably also in plants. Arabidopsis harbors two TCTP genes, AtTCTP1 (At3g16640), which is an important mitotic regulator, and AtTCTP2 (At3g05540), which is considered a pseudogene. Nevertheless, we have obtained evidence suggesting that this gene is functional. Indeed, a T-DNA insertion mutant, SALK_045146, displays a lethal phenotype during early rosette stage. Also, both the AtTCTP2 promoter and structural gene are functional, and heterozygous plants show delayed development. AtTCTP1 cannot compensate for the loss of AtTCTP2, since the accumulation levels of the AtTCTP1 transcript are even higher in heterozygous plants than in wild-type plants. Leaf explants transformed with Agrobacterium rhizogenes harboring AtTCTP2, but not AtTCTP1, led to whole plant regeneration with a high frequency. Insertion of a sequence present in AtTCTP1 but absent in AtTCTP2 demonstrates that it suppresses the capacity for plant regeneration; also, this phenomenon is enhanced by the presence of TCTP (AtTCTP1 or 2) in the nuclei of root cells. This confirms that AtTCTP2 is not a pseudogene and suggests the involvement of certain TCTP isoforms in vegetative reproduction in some plant species. PMID:26191065

  1. Novel regenerable sorbent for mercury capture from flue gases of coal-fired power plant

    SciTech Connect

    Yan Liu; David J.A. Kelly; Hongqun Yang; Christopher C.H. Lin; Steve M. Kuznicki; Zhenghe Xu

    2008-08-15

    A natural chabazite-based silver nanocomposite (AgMC) was synthesized to capture mercury from flue gases of coal-fired power plants. Silver nanoparticles were engineered on zeolite through ion-exchange of sodium ions with silver ions, followed by thermal annealing. Mercury sorption test using AgMC was performed at various temperatures by exposing it to either pulse injection of mercury or continuous mercury flow. A complete capture of mercury by AgMC was achieved up to a capture temperature of 250{sup o}C. Nano silver particles were shown to be the main active component for mercury capture by amalgamation mechanism. Compared with activated carbon-based sorbents, the sorbent prepared in this study showed a much higher mercury capture capacity and upper temperature limit for mercury capture. More importantly, the mercury captured by the spent AgMC could be easily released for safe disposal and the sorbent regenerated by simple heating at 400{sup o}C. Mercury capture tests performed in real flue gas environment showed a much higher level of mercury capture by AgMC than by other potential mercury sorbents tested. In our mercury capture tests, the AgMC exposed to real flue gases showed an increased mercury capture efficiency than the fresh AgMC. 38 refs., 6 figs.

  2. Structural and functional organisation of regenerated plant protoplasts exposed to microgravity on Biokosmos 9

    NASA Astrophysics Data System (ADS)

    Klimchuk, D. A.; Kordyum, E. L.; Danevich, L. A.; Tarnavskaya, E. B.; Tairbekov, M. G.; Iversen, T.-H.; Baggerud, C.; Rasmussen, O.

    Preparatory experiments for the IML-1 mission using plant protoplasts, were flown on a 14-day flight on Biokosmos 9 in September 1989. Thirty-six hours before launch of the biosatellite, protoplasts were isolated from hypocotyl cells of rapeseed (Brassica napus) and suspension cultures of carrot (Daucus carota). Ultrastructural and fluorescence analysis of cell aggregates from these protoplasts, cultured under microgravity conditions, have been performed. In the flight samples as well as in the ground controls, a portion of the total number of protoplasts regenerated cell walls. The processes of cell differentiation and proliferation under micro-g did not differ significantly from those under normal gravity conditions. However, in micro-g differences were observed in the ultrastructure of some organelles such as plastids and mitochondria. There was also an increase in the frequency of the occurrence of folds formed by the plasmalemma together with an increase in the degree of complexity of these folds. In cell cultures developed under micro-g conditions, the calcium content tends to decrease, compared to the ground control. Different aspects of using isolated protoplasts for clarifying the mechanisms of biological effects of microgravity are discussed.

  3. Plant regeneration after long-term callus culture in clones of Asparagus officinalis L.

    PubMed

    Pontaroli, A C; Camadro, E L

    2005-12-01

    Callus growth and plant regeneration from long-term callus cultures were studied in two elite clones of Asparagus officinalis cv. Argenteuil, to establish a suitable protocol for a prospective in vitro selection program. Callus initiation and growth was evaluated on MS medium with 3% sucrose, 0.9% agar, 1 mg x l(-1) kinetin, and three levels of 2,4-D. The highest callus relative growth was obtained on medium with 1.5 mg x l(-1) 2,4-D and 1 mg x l(-1) kinetin. Shoot primordia (SP) induction from > 18-months-old calluses was evaluated on several media; the highest percentage of SP induction (89%) and average number of SP per callus (8.6) were obtained with clone "265" on MS medium with 5 mg x l(-1) 2iP, 1 mg x l(-1) IAA, 3% sucrose and 0.9% agar. The highest percentage of root induction (100%) was achieved with clone '265' on MS medium with 0.1 mg x l(-1) kinetin, 0.1 mg x l(-1) NAA, 1.32 mg x l(-1) ancymidol, 7% glucose and 0.8% agar. Important medium x genotype interactions were detected, pointing to the need of adjusting this and other in vitro protocols for specific asparagus genotypes. PMID:16524253

  4. High Uniformity of plants regenerated from cytogenetically variable embryogenic suspension cultures of poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch).

    PubMed

    Geier, T; Beck, A; Preil, W

    1992-04-01

    Shoot tip explants, callus and embryogenic cell suspensions of Euphorbia pulcherrima have been examined for quantitative variation in nuclear DNA content by means of cytophotometry. Increasing instability was found in calli and cell suspensions from Erlenmeyer flask and bioreactor culture. Nuclear DNA content ranged from 2C up to 32 C. Plants regenerated from embryogenic cell suspensions, however, were highly uniform with regard to phenotype and ploidy level indicating strongly impaired embryogenic potential of polyploid, aneuploid or other genetically altered cells. PMID:24213549

  5. Adsorptive removal of methylene blue by CuO-acid modified sepiolite as effective adsorbent and its regeneration with high-temperature gas stream.

    PubMed

    Su, Chengyuan; Wang, Liang; Chen, Menglin; Huang, Zhi; Lin, Xiangfeng

    2016-01-01

    In this study, the dynamic adsorption of methylene blue dye onto CuO-acid modified sepiolite was investigated. Meanwhile, the equilibrium and kinetic data of the adsorption process were studied to understand the adsorption mechanism. Furthermore, a high-temperature gas stream was applied to regenerate the adsorbent. The results showed that the Langmuir isotherm model was applied to describe the adsorption process. The positive value of enthalpy change indicated that the adsorption process was endothermic in nature. In the dynamic adsorption process, the best adsorption performance was achieved when the ratio of column height to diameter was 2.56 and the treatment capacity was 6 BV/h. The optimal scenario for regeneration experiments was the regeneration temperature of 550-650 °C, the space velocity of 100 min(-1) and the regeneration time of 10 min. The effective adsorption of CuO-acid modified sepiolite was kept for 12 cycles of adsorption and regeneration. PMID:27533859

  6. In vitro callus induction and plantlet regeneration of Achyranthes aspera L., a high value medicinal plant

    PubMed Central

    Sen, Monokesh Kumer; Nasrin, Shamima; Rahman, Shahedur; Jamal, Abu Hena Mostofa

    2014-01-01

    Objective To study callus induction from different explants (internode, leaf, root) and in vitro plantlets propagation from medicinally important plant Achyranthes aspera L. Methods Sterilized explants were prepared by using 0.1% HgCl2 and 0.5% Bavistin and callus was obtained when cultured onto Murashige Skoog's (MS) medium by using different concentrations and combination of 2,4-D, NAA, BAP, IAA, IBA with 3% sucrose and 0.8% agar. Induced callus was immediately transferred to MS medium containing at different concentrations of phytohormones for shootlets and rootlets induction respectively. Results Sterilization treatment of 0.1% HgCl2 for 2-3 min and Bavistin 0.5% for 10-12 min showed the highest percentage of asepsis and survival rate. Maximum induction of callus was obtained from a combination of 2.0 mg/L 2,4-D and 0.5 mg/L NAA from leaf. Highest shootlets number (4.83±0.17) and length (3.8±0.16) cm were observed on full strength MS medium when fortified with BAP 4.0 mg/L and KIN 0.5 mg/L. Concerted efforts of BAP 2.0 mg/L and NAA 0.5 mg/L on full strength MS medium showed highest leaf number (6.77±0.94). In vitro raised shoots were allowed to root on different strengths of MS medium fortified with IAA and IBA at different concentrations. Experimentally, 3.0 mg/L IBA was enabled to induce maximum rootlets number (10.0±9.82) on full strength MS medium. Afterwards, regenerated shoots with well developed roots were successfully subjected to hardening process and were acclimatized. The survived plantlets showed 66.67% survival frequency without any morphological abnormality. Conclusions The results demonstrated that different explants were good source of callus induction, morphology analysis as well as indirect plantlets regeneration. PMID:24144129

  7. Salicylic acid-derived poly(anhydride-ester) electrospun fibers designed for regenerating the peripheral nervous system

    PubMed Central

    Griffin, Jeremy; Delgado-Rivera, Roberto; Meiners, Sally; Uhrich, Kathryn E.

    2011-01-01

    Continuous biomaterial advances and the regenerating potential of the adult human peripheral nervous system offer great promise for restoring full function to innervated tissue following traumatic injury via synthetic nerve guidance conduits. To most effectively facilitate nerve regeneration, a tissue engineering scaffold within a conduit must be similar to the linear microenvironment of the healthy nerve. To mimic the native nerve structure, aligned poly(lactic-co-glycolic acid)/bioactive polyanhydride fibrous substrates were fabricated through optimized electrospinning parameters with diameters of 600 ± 200 nm. Scanning electron microscopy images show fibers with a high degree of alignment. Schwann cells and dissociated rat dorsal root ganglia demonstrated elongated and healthy proliferation in a direction parallel to orientated electrospun fibers with significantly longer Schwann cell process length and neurite outgrowth when compared to randomly orientated fibers. Results suggest that an aligned polyanhydride fiber mat holds tremendous promise as a supplement scaffold for the interior of a degradable polymer nerve guidance conduit. Bioactive salicylic acid based polyanhydride fibers are not limited to nerve regeneration and offer exciting promise for a wide variety of biomedical applications. PMID:21442724

  8. Bone regeneration using hyaluronic acid-based hydrogel with bone morphogenic protein-2 and human mesenchymal stem cells.

    PubMed

    Kim, Jungju; Kim, In Sook; Cho, Tae Hyung; Lee, Kyu Back; Hwang, Soon Jung; Tae, Giyoong; Noh, Insup; Lee, Sang Hoon; Park, Yongdoo; Sun, Kyung

    2007-04-01

    Acrylated hyaluronic acid (HA) was used as a scaffold for bone morphogenic protein-2 (BMP-2) and human mesenchymal stem cells (hMSCs) for rat calvarial defect regeneration. HA was acrylated by two-step reactions: (1) introduction of an amine group using adipic acid dihydrazide (ADH); (2) acrylation by N-acryloxysuccinimide. Tetrathiolated poly(ethylene) glycol (PEG-SH(4)) was used as a cross-linker by a Michael-type addition reaction and the hydrogel was formed within 10min under physiological conditions. This hydrogel is degraded completely by 100U/ml hyaluronidase in vitro. hMSCs and/or BMP-2 was added during gelation. Cellular viability in vitro was increased up to 55% in the hydrogels with BMP-2 compared with the control. For in vivo calvarial defect regeneration, five different samples (i.e., control, hydrogel, hydrogel with BMP-2, hydrogel with MSCs, and hydrogel with BMP-2 and MSCs) were implanted for 4 weeks. The histological results demonstrated that the hydrogels with BMP-2 and MSCs had the highest expression of osteocalcin and mature bone formation with vascular markers, such as CD31 and vascular endothelial growth factors, compared with the other samples. This study demonstrated that HA base hydrogel can be used for cell and growth factor carriers for tissue regeneration. PMID:17208295

  9. Apparatus and method for the thermal regeneration of matter in water treatment plants

    SciTech Connect

    Marquardt, K.

    1980-12-02

    Apparatus and methods are disclosed that provide a quasicontinuous thermal regeneration system for ion exchange resins and adsorption media (matter) as used, for example, in desalinization processes, comprising an operating (desalinization) vessel, means for transferring measured amounts of matter therefrom to successive regeneration and cooling means and recycle back to the operating vessel. Heat exchange means are provided to transfer residual heat from the cooling step to the regeneration step, transport water is recycled in the process with minimal losses, and optional water softening and decarbonizing pre-treatment and chemical post-treatment steps may be included, the latter to remove dirt and heavy metals from the regenerated matter prior to recycle to the operating vessel.

  10. [Induction and in vitro culture of hairy roots of Dianthus caryophyllus and its plant regeneration].

    PubMed

    Shi, Heping; Zhu, Yuanfeng; Wang, Bei; Sun, Jiangbing; Huang, Shengqin

    2014-11-01

    To use Agrobacterium rhizogenes-induced hairy roots to create new germplasm of Dianthus caryophyllus, we transformed D. caryophyllus with A. rhizogenes by leaf disc for plant regeneration from hairy roots. The white hairy roots could be induced from the basal surface of leaf explants of D. caryophyllus 12 days after inoculation with A. rhizogenes ATCC15834. The percentage of the rooting leaf explants was about 90% 21 days after inoculation. The hairy roots could grow rapidly and autonomously in liquid or solid phytohormone-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and silica gel thin-layer chromatography of opines from D. caryophyllus hairy roots. Hairy roots could form light green callus after cultured on MS+6-BA 1.0-3.0 mg/L + NAA 0.1-0.2 mg/L for 15 days. The optimum medium for adventitious shoots formation was MS + 6-BA 2.0 mg/L + NAA 0.02 mg/L, where the rate of adventitious shoot induction was 100% after cultured for 6 weeks. The mean number of adventitious shoot per callus was 30-40. The adventitious shoots can form roots when cultured on phytohormone-free 1/2 MS or 1/2 MS +0.5 mg/L NAA for 10 days. When the rooted plantlets transplanted in the substrate mixed with perlite sand and peat (volume ratio of 1:2), the survival rate was above 95%. PMID:25985525

  11. Effects of invasive alien kahili ginger (Hedychium gardnerianum) on native plant species regeneration in a Hawaiian rainforest

    USGS Publications Warehouse

    Minden, V.; Jacobi, J.D.; Porembski, S.; Boehmer, H.J.

    2010-01-01

    Questions: Does the invasive alien Hedychium gardnerianum (1) replace native understory species, (2) suppress natural regeneration of native plant species, (3) increase the invasiveness of other non-native plants and (4) are native forests are able to recover after removal of H. gardnerianum. Location: A mature rainforest in Hawai'i Volcanoes National Park on the island of Hawai'i (about 1200 m. a.s.l.; precipitation approximately 2770mm yr-1). Study sites included natural plots without effects of alien plants, ginger plots with a H. gardnerianum-domimted herb layer and cleared plots treated with herbicide to remove alien plants. Methods: Counting mature trees, saplings and seedlings of native and alien plant species. Using nonparametric H-tests to compare impact of H. gardnerianum on the structure of different sites. Results: Results confirmed the hypothesis that H. gardnerianum has negative effects on natural forest dynamics. Lower numbers of native tree seedlings and saplings were found on ginger-dominated plots. Furthermore, H. gardnerianum did not show negative effects on the invasive alien tree species Psidium cattleianum. Conclusions: This study reveals that where dominance of H. gardnerianum persists, regeneration of the forest by native species will be inhibited. Furthermore, these areas might experience invasion by P. cattleianum, resulting in displacement of native canopy species in the future, leading to a change in forest structure and loss of other species dependent on natural rainforest, such as endemic birds. However, if H. gardnerianum is removed the native Hawaiian forest is likely to regenerate and regain its natural structure. ?? 2009 International Association for Vegetation Science.

  12. Hyaluronic acid production and hyaluronidase activity in the newt iris during lens regeneration

    SciTech Connect

    Kulyk, W.M.; Zalik, S.E.; Dimitrov, E.

    1987-09-01

    The process of lens regeneration in newts involves the dedifferentiation of pigmented iris epithelial cells and their subsequent conversion into lens fibers. In vivo this cell-type conversion is restricted to the dorsal region of the iris. We have examined the patterns of hyaluronate accumulation and endogenous hyaluronidase activity in the newt iris during the course of lens regeneration in vivo. Accumulation of newly synthesized hyaluronate was estimated from the uptake of (/sup 3/H)glucosamine into cetylpyridinium chloride-precipitable material that was sensitive to Streptomyces hyaluronidase. Endogenous hyaluronidase activity was determined from the quantity of reducing N-acetylhexosamine released upon incubation of iris tissue extract with exogenous hyaluronate substrate. We found that incorporation of label into hyaluronate was consistently higher in the regeneration-activated irises of lentectomized eyes than in control irises from sham-operated eyes. Hyaluronate labeling was higher in the dorsal (lens-forming) region of the iris than in ventral (non-lens-forming) iris tissue during the regeneration process. Label accumulation into hyaluronate was maximum between 10 and 15 days after lentectomy, the period of most pronounced dedifferentiation in the dorsal iris epithelium. Both normal and regenerating irises demonstrated a high level of endogenous hyaluronidase activity with a pH optimum of 3.5-4.0. Hyaluronidase activity was 1.7 to 2 times higher in dorsal iris tissue than in ventral irises both prior to lentectomy and throughout the regeneration process. We suggest that enhanced hyaluronate accumulation may facilitate the dedifferentiation of iris epithelial cells in the dorsal iris and prevent precocious withdrawal from the cell cycle. The high level of hyaluronidase activity in the dorsal iris may promote the turnover and remodeling of extracellular matrix components required for cell-type conversion.

  13. Hyaluronic acid based hydrogel system for soft tissue regeneration and drug delivery

    NASA Astrophysics Data System (ADS)

    Jha, Amit Kumar

    We have developed hyaluronic acid (HA)-based, biomimetic hydrogel matrices that are hierarchically structured, mechanically robust and biologically active. Specifically, HA-based hydrogel particles (HGPs) with controlled sizes, defined porosity, and improved stability were synthesized using different inverse emulsion systems and crosslinking chemistries. The resultant particles either contained residual functional groups or were rendered reactive by subsequent chemical modifications. HA-based doubly crosslinked networks (DXNs) were synthesized via covalent crosslinking of HA HGPs with soluble HA macromers carrying mutually reactive functional groups. These hybrid matrices are hierarchical in nature, consisting of densely crosslinked HGPs integrated in a loosely connected secondary matrix. Their mechanical properties and degradation kinetics can be readily tuned by varying the particle size, functional group density, intra- and interparticle crosslinking. To improve the biological functions of HA HGPs, perlecan domain I (PlnDI), a basement membrane proteoglycan that has strong affinity for various heparin binding growth factors (HBGFs), was successfully conjugated to the particles through the core protein via a flexible poly(ethylene glycol) (PEG) linker. The immobilized PlnDI maintains its ability to bind bone morphogenetic proteins (BMP-2) and modulates its in vitro release. A similar, sustained release of BMP-2 was achieved by encapsulating BMP-2-loaded HGPs within a photocrosslinked HA matrix. When encapsulated in HA DXNs, primary bovine chondrocytes were able to maintain their phenotype, proliferate readily and produce abundant glycosaminoglycan. Finally, cell-adhesive HA DXNs were fabricated by encapsulating gelatin-decorated HA HGPs in a secondary HA matrix. Human MSCs were shown to adhere to the composite matrix through the focal adhesion sites clustered on particle surface. The cell-adhesive composite matrices supported hMSC proliferation and migration into

  14. Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration.

    PubMed

    Talal, Ahmed; McKay, I J; Tanner, K E; Hughes, Francis J

    2013-09-01

    The technique of guided tissue regeneration (GTR) has evolved over recent years in an attempt to achieve periodontal tissue regeneration by the use of a barrier membrane. However, there are significant limitations in the currently available membranes and overall outcomes may be limited. A degradable composite material was investigated as a potential GTR membrane material. Polylactic acid (PLA) and nanohydroxyapatite (nHA) composite was analysed, its bioactive potential and suitability as a carrier system for growth factors were assessed. The effect of nHA concentrations and the addition of platelet derived growth factor (PDGF) on osteoblast proliferation and differentiation was investigated. The bioactivity was dependent on the nHA concentration in the films, with more apatite deposited on films containing higher nHA content. Osteoblasts proliferated well on samples containing low nHA content and differentiated on films with higher nHA content. The composite films were able to deliver PDGF and cell proliferation increased on samples that were pre-absorbed with the growth factor. nHA-PLA composite films are able to deliver active PDGF. In addition the bioactivity and cell differentiation was higher on films containing more nHA. The use of a nHA-PLA composite material containing a high concentration of nHA may be a useful material for GTR membrane as it will not only act as a barrier, but may also be able to enhance bone regeneration by delivery of biologically active molecules. PMID:23832451

  15. Effects of gamma-irradiation on biosynthesis of different types of ribonucleic acids in normal and regenerating rat liver.

    PubMed Central

    Markov, G G; Dessev, G N; Russev, G C; Tsanev, R G

    1975-01-01

    1. The effect of gamma-irradiation (4000rd) on the synthesis of ribosomal (pre-rRNA) and heterogeneous nuclear RNA (pre-mRNA) in normal and in regenerating rat liver was studied by using 40 min labelling with [6(-14)C]orotic acid. 2. Partial hepatectomy caused a sharp transient increase in the specific radioactivity of the endogenous low-molecular-weight RNA precursors in the livers of both normal and irradiated rats. Irradiation of intact animals did not affect the pool. 3. Irradiation enhanced the synthesis of pre-rRNA for at least 12h. The synthesis of pre-mRNA was also enhanced, but only in the first 3h after irradiation. 4. Partial hepatectomy strongly stimulated the synthesis of both pre-rRNA and pre-mRNA. 5. The synthesis of pre-rRNA was enhanced also in regenerating liver of animals irradiated before or after the operation. The conclusion can be drawn that the early increase in the synthesis of ribosomal RNA is a non-specific cellular response to different injuring factors. 6. The only case where irradiation caused an early inhibition of RNA synthesis was that of pre-mRNA in regenerating liver. This supports the hypothesis that ionizing radiation does not suppress the transcription per se but affects the mechanisms of activation of new genes (cellular programming). PMID:1147904

  16. Improved zeolite regeneration processes for preparing saturated branched-chain fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ferrierite zeolite solid is an excellent catalyst for the skeletal isomerization of unsaturated linear-chain fatty acids (i.e., oleic acid) to unsaturated branched-chain fatty acids (i.e., iso-oleic acid) follow by hydrogenation to give saturated branched-chain fatty acids (i.e., isostearic acid). ...

  17. Nanostructured polyurethane-poly-lactic-co-glycolic acid scaffolds increase bladder tissue regeneration: an in vivo study

    PubMed Central

    Yao, Chang; Hedrick, Matt; Pareek, Gyan; Renzulli, Joseph; Haleblian, George; Webster, Thomas J

    2013-01-01

    Although showing much promise for numerous tissue engineering applications, polyurethane and poly-lactic-co-glycolic acid (PLGA) have suffered from a lack of cytocompatibility, sometimes leading to poor tissue integration. Nanotechnology (or the use of materials with surface features or constituent dimensions less than 100 nm in at least one direction) has started to transform currently implanted materials (such as polyurethane and PLGA) to promote tissue regeneration. This is because nanostructured surface features can be used to change medical device surface energy to alter initial protein adsorption events important for promoting tissue-forming cell functions. Thus, due to their altered surface energetics, the objective of the present in vivo study was to create nanoscale surface features on a new polyurethane and PLGA composite scaffold (by soaking the polyurethane side and PLGA side in HNO3 and NaOH, respectively) and determine bladder tissue regeneration using a minipig model. The novel nanostructured scaffolds were further functionalized with IKVAV and YIGSR peptides to improve cellular responses. Results provided the first evidence of increased in vivo bladder tissue regeneration when using a composite of nanostructured polyurethane and PLGA compared with control ileal segments. Due to additional surgery, extended potentially problematic healing times, metabolic complications, donor site morbidity, and sometimes limited availability, ileal segment repair of a bladder defect is not optimal and, thus, a synthetic analog is highly desirable. In summary, this study indicates significant promise for the use of nanostructured polyurethane and PLGA composites to increase bladder tissue repair for a wide range of regenerative medicine applications, such as regenerating bladder tissue after removal of cancerous tissue, disease, or other trauma. PMID:24039415

  18. Nanostructured polyurethane-poly-lactic-co-glycolic acid scaffolds increase bladder tissue regeneration: an in vivo study.

    PubMed

    Yao, Chang; Hedrick, Matt; Pareek, Gyan; Renzulli, Joseph; Haleblian, George; Webster, Thomas J

    2013-01-01

    Although showing much promise for numerous tissue engineering applications, polyurethane and poly-lactic-co-glycolic acid (PLGA) have suffered from a lack of cytocompatibility, sometimes leading to poor tissue integration. Nanotechnology (or the use of materials with surface features or constituent dimensions less than 100 nm in at least one direction) has started to transform currently implanted materials (such as polyurethane and PLGA) to promote tissue regeneration. This is because nanostructured surface features can be used to change medical device surface energy to alter initial protein adsorption events important for promoting tissue-forming cell functions. Thus, due to their altered surface energetics, the objective of the present in vivo study was to create nanoscale surface features on a new polyurethane and PLGA composite scaffold (by soaking the polyurethane side and PLGA side in HNO₃ and NaOH, respectively) and determine bladder tissue regeneration using a minipig model. The novel nanostructured scaffolds were further functionalized with IKVAV and YIGSR peptides to improve cellular responses. Results provided the first evidence of increased in vivo bladder tissue regeneration when using a composite of nanostructured polyurethane and PLGA compared with control ileal segments. Due to additional surgery, extended potentially problematic healing times, metabolic complications, donor site morbidity, and sometimes limited availability, ileal segment repair of a bladder defect is not optimal and, thus, a synthetic analog is highly desirable. In summary, this study indicates significant promise for the use of nanostructured polyurethane and PLGA composites to increase bladder tissue repair for a wide range of regenerative medicine applications, such as regenerating bladder tissue after removal of cancerous tissue, disease, or other trauma. PMID:24039415

  19. Osteoblast de- and redifferentiation are controlled by a dynamic response to retinoic acid during zebrafish fin regeneration.

    PubMed

    Blum, Nicola; Begemann, Gerrit

    2015-09-01

    Zebrafish restore amputated fins by forming tissue-specific blastema cells that coordinately regenerate the lost structures. Fin amputation triggers the synthesis of several diffusible signaling factors that are required for regeneration, raising the question of how cell lineage-specific programs are protected from regenerative crosstalk between neighboring fin tissues. During fin regeneration, osteoblasts revert from a non-cycling, mature state to a cycling, preosteoblastic state to establish a pool of progenitors within the blastema. After several rounds of proliferation, preosteoblasts redifferentiate to produce new bone. Blastema formation and proliferation are driven by the continued synthesis of retinoic acid (RA). Here, we find that osteoblast dedifferentiation and redifferentiation are inhibited by RA signaling, and we uncover how the bone regenerative program is achieved against a background of massive RA synthesis. Stump osteoblasts manage to contribute to the blastema by upregulating expression of the RA-degrading enzyme cyp26b1. Redifferentiation is controlled by a presumptive gradient of RA, in which high RA levels towards the distal tip of the blastema suppress redifferentiation. We show that this might be achieved through a mechanism involving repression of Bmp signaling and promotion of Wnt/β-catenin signaling. In turn, cyp26b1(+) fibroblast-derived blastema cells in the more proximal regenerate serve as a sink to reduce RA levels, thereby allowing differentiation of neighboring preosteoblasts. Our findings reveal a mechanism explaining how the osteoblast regenerative program is protected from adverse crosstalk with neighboring fibroblasts that advances our understanding of the regulation of bone repair by RA. PMID:26253409

  20. ELECTROCHEMICAL CHROMIC ACID REGENERATION PROCESS: FITTING OF MEMBRANE TRANSPORT PROPERTIES. (R827125)

    EPA Science Inventory

    Abstract

    A mathematical model was developed to predict changes in contaminant concentrations with time, and to estimate contaminant fluxes due to migration, diffusion, and convection in a laboratory-scale batch electrolysis cell for the regeneration of contaminated har...

  1. Reverse reaction of malic enzyme for HCO3- fixation into pyruvic acid to synthesize L-malic acid with enzymatic coenzyme regeneration.

    PubMed

    Ohno, Yoko; Nakamori, Toshihiko; Zheng, Haitao; Suye, Shin-ichiro

    2008-05-01

    Malic enzyme [L-malate: NAD(P)(+) oxidoreductase (EC 1.1.1.39)] catalyzes the oxidative decarboxylation of L-malic acid to produce pyruvic acid using the oxidized form of NAD(P) (NAD(P)(+)). We used a reverse reaction of the malic enzyme of Pseudomonas diminuta IFO 13182 for HCO(3)(-) fixation into pyruvic acid to produce L-malic acid with coenzyme (NADH) generation. Glucose-6-phosphate dehydrogenase (EC1.1.1.49) of Leuconostoc mesenteroides was suitable for coenzyme regeneration. Optimum conditions for the carboxylation of pyruvic acid were examined, including pyruvic acid, NAD(+), and both malic enzyme and glucose-6-phosphate dehydrogenase concentrations. Under optimal conditions, the ratio of HCO(3)(-) and pyruvic acid to malic acid was about 38% after 24 h of incubation at 30 degrees C, and the concentration of the accumulated L-malic acid in the reaction mixture was 38 mM. The malic enzyme reverse reaction was also carried out by the conjugated redox enzyme reaction with water-soluble polymer-bound NAD(+). PMID:18460807

  2. Optimized growth and plant regeneration for callus of Lilium longiflorum cv. Nellie White

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rates of growth and regeneration were compared for compact callus, friable callus, and suspension cells of Lilium longiflorum cv. Nellie White to determine the optimal culture conditions. The fresh weight was higher for compact callus induced from bulb scales cultured on Murashige and Skoog’s m...

  3. Guided bone regeneration by poly(lactic-co-glycolic acid) grafted hyaluronic acid bi-layer films for periodontal barrier applications.

    PubMed

    Park, Jung Kyu; Yeom, Junseok; Oh, Eun Ju; Reddy, Mallikarjuna; Kim, Jong Young; Cho, Dong-Woo; Lim, Hyun Pil; Kim, Nam Sook; Park, Sang Won; Shin, Hong-In; Yang, Dong Jun; Park, Kwang Bum; Hahn, Sei Kwang

    2009-11-01

    A novel protocol for the synthesis of biocompatible and degradation controlled poly(lactic-co-glycolic acid) grafted hyaluronic acid (HA-PLGA) was successfully developed for periodontal barrier applications. HA was chemically modified with adipic acid dihydrazide (ADH) in the mixed solvent of water and ethanol, which resulted in a high degree of HA modification up to 85 mol.%. The stability of HA-ADH to enzymatic degradation by hyaluronidase increased with ADH content in HA-ADH. When the ADH content in HA-ADH was higher than 80 mol.%, HA-ADH became soluble in dimethyl sulfoxide and could be grafted to the activated PLGA with N,N'-dicyclohexyl carbodiimide and N-hydroxysuccinimide. The resulting HA-PLGA was used for the preparation of biphasic periodontal barrier membranes in chloroform. According to in vitro hydrolytic degradation tests in phosphate buffered saline, HA-PLGA/PLGA blend film with a weight ratio of 1/2 degraded relatively slowly compared to PLGA film and HA coated PLGA film. Four different samples of a control, OSSIX(TM) membrane, PLGA film, and HA-PLGA/PLGA film were assessed as periodontal barrier membranes for the calvarial critical size bone defects in SD rats. Histological and histomorphometric analyses revealed that HA-PLGA/PLGA film resulted in the most effective bone regeneration compared to other samples with a regenerated bone area of 63.1% covering the bone defect area. PMID:19477304

  4. In vitro regeneration in Sarcostemma acidum (Roxb.) -an important medicinal plant of semi-arid ecosystem of Rajasthan, India.

    PubMed

    Rathore, Mahender S; Shekhawat, Narpat S

    2013-04-01

    An efficient regeneration protocol for Sarcostemma acidum - an important medicinal plant has been established. Callus initiated from nodal explant on MS medium with 2.0 mg L(-1) of NAA + additives. Callus initiated was subcultured on MS medium containing various concentrations of NAA or 2,4-D. Out of these combinations, MS medium +1.0 mg L(-1) of NAA + additives was found to be effective for the multiplication of callus. Subculture was done after an interval of 20-22 days. For differentiation of callus BAP or Kinetin alone was found to be less effective. Maximum frequency of shoot regeneration recorded on MS medium +1.0 mg L(-1) of BAP + 0.5 mg L(-1) of Kinetin and 0.1 mg L(-1) of NAA + additives. The in vitro differentiated shoots were excised and inoculated on 1/4 strength MS medium +2.0 mg L(-1) of IBA + 0.02 % activated charcoal for in vitro rooting. Maximum response (90 %) was recorded on this medium. In vitro differentiated shoots were inoculated on autoclaved soilrite® after treatment with root inducing auxins. Ex vitro rooting in this plant species has been reported for the first time. Eighty five percent of the shoots rooted under ex vitro conditions. Both in vitro and ex vitro rooted plantlets were hardened in a green house. PMID:24431495

  5. The influence of vapor superheating on the level of heat regeneration in a subcritical ORC coupled with gas power plant

    NASA Astrophysics Data System (ADS)

    Wiśniewski, Sławomir; Borsukiewicz-Gozdur, Aleksandra

    2010-09-01

    The authors presented problems related to utilization of exhaust gases of the gas turbine unit for production of electricity in an Organic Rankine Cycle (ORC) power plant. The study shows that the thermal coupling of ORC cycle with a gas turbine unit improves the efficiency of the system. The undertaken analysis concerned four the so called "dry" organic fluids: benzene, cyclohexane, decane and toluene. The paper also presents the way how to improve thermal efficiency of Clausius-Rankine cycle in ORC power plant. This method depends on applying heat regeneration in ORC cycle, which involves pre-heating the organic fluid via vapour leaving the ORC turbine. As calculations showed this solution allows to considerably raise the thermal efficiency of Clausius-Rankine cycle.

  6. Evaluation of combustion processes for destruction of liquid organic wastes in a sulfuric-acid regeneration furnace

    SciTech Connect

    Ouchida, P.

    1985-11-01

    The test mechanism, efforts, and results associated with incineration of liquid organic wastes in a sulfuric-acid regeneration furnace are described in the report. Industrial wastes representing those to be ultimately processed, if the system is acceptable, were not available or could not be clearly characterized as to chemical nature. A synthetic, or surrogate, mix was therefore burned with the alkylation acid to allow an analysis of potential emissions to be made. The tests conducted were broken down into three categories based on furnace operating conditions: base line (spent alkylation acid, only, being fed into the furnace under typical operating conditions); normal (spent alkylation acid spiked with the synthetic mix fed into the furnace under typical operating conditions) and; low O/sub 2/ (spent alkylation acid spiked with the synthetic mix fed into the furnace operating at nonstandard, or failure mode, conditions of low O/sub 2/ and low temperature). These test conditions helped established an operating envelope within which efficient combustion could be assured.

  7. In vitro plant regeneration from immature cotyledon explants of macadamia (Macadamia tetraphylla L. Johnson).

    PubMed

    Mulwa, Richard M S; Bhalla, Prem L

    2006-12-01

    The macadamia tree, an Australian native, is highly valued for its nuts. Macadamia improvement programs so far have relied on conventional breeding and selection. The production of improved cultivars required to meet future demands could be accelerated by the application of modern biotechnological techniques, but this requires an efficient and reproducible regeneration system that has not yet been established for macadamia. We report here shoot regeneration from immature cotyledon explants of macadamia. Adventitious buds were induced on the cotyledon explants from fruits collected at 140 and 190 days after full bloom (DAFB) on MS medium supplemented with either 10 or 15 microM TDZ. The addition of 2% coconut milk (CM) to 10 microM TDZ containing media resulted in enhanced adventitious bud induction from 190 DAFB explants. Further shoot development from the induced buds was depressed in media containing TDZ + CM; the addition of 0.001 microM IAA to this combination doubled shoot development, from 1.9-3.9 shoots per explant. The transfer of bud clumps to media supplemented with 8.8 microM BA alone or in combination with either 0.14 microM GA(3) or 0.001 microM IAA significantly increased shoot production from the previously induced explants by 1.5-2 times of that observed in TDZ + CM medium. Histological examinations revealed that shoot regeneration was primarily by organogenesis originating from cells on or just below the cut surfaces of explants. PMID:16858554

  8. Conceptual design of a coal-fired MHD retrofit plant. Topical report, Seed Regeneration System Study 2

    SciTech Connect

    Not Available

    1992-11-01

    Westinghouse Advanced Energy Systems (WAES), through Contract No. DE-AC22-87PC79668 funded by US DOE/PETC, is conducting a conceptual design study to evaluate a coal-fired magnetohydrodynamic (MHD) retrofit of a utility plant of sufficient size to demonstrate the technical and future economic viability of an MHD system operating within an electric utility environment. The objective of this topical report is to document continuing seed regeneration system application studies and the definition of will system integration requirements for the Scholz MHD retrofit plant design. MHD power plants require the addition of a seeding material in the form of potassium to enhance the ionization of the high temperature combustion gas in the MHD channel. This process has an added environmental advantage compared to other types of coal-fired power plants in that the potassium combines with the naturally occurring sulfur in the coal to form a potassium sulfate flyash (K{sub 2}SO{sub 4}) which can be removed from the process by appropriate particulate control equipment. Up to 100% of the Sulfur in the coal can be removed by this process thereby providing environmentally clean power plant operation that is better than required by present and anticipated future New Source Performance Standards (NSPS).

  9. Gum tragacanth/poly(l-lactic acid) nanofibrous scaffolds for application in regeneration of peripheral nerve damage.

    PubMed

    Ranjbar-Mohammadi, Marziyeh; Prabhakaran, Molamma P; Bahrami, S Hajir; Ramakrishna, Seeram

    2016-04-20

    Nanofibrous nerve guides have gained huge interest in supporting the peripheral nerve regeneration due to their abilities to simulate the topography, mechanical, biological and extracellular matrix morphology of native tissue. Gum tragacanth (GT) is a biocompatible mixture of polysaccharides that has been used in biomedical applications. During this study, we fabricated aligned and random nanofibers from poly(l-lactic acid) and gum tragacanth (PLLA/GT) in various ratios (100:0, 75:25, and 50:50) by electrospinning. Scanning electron microscope demonstrated smooth and uniform nanofibers with diameters in the range of 733±65nm and 226±73nm for align PLLA and random PLLA/GT 50:50 nanofibers, respectively. FTIR analysis, contact angle, in vitro biodegradation and tensile measurements were carried out to evaluate the chemical and mechanical properties of the different scaffolds. PLLA/GT 75:25 exhibited the most balanced properties compared to other scaffolds and was used for in vitro culture of nerve cells (PC12) to assess the potential of using these scaffolds as a substrate for nerve regeneration. The cells were found to attach and proliferate on aligned PLLA/GT 75:25 scaffolds, expressing bi-polar neurite extensions and the orientation of nerve cells was along the direction of the fiber alignment. Results of 8 days of in vitro culture of PC12 cells on aligned PLLA/GT 75:25 nanofibers, showed 20% increase in cell proliferation compared to PLLA/GT 75:25 random nanofibers. PLLA/GT 75:25 aligned nanofibers acted as a favorable cue to support neurite outgrowth and nerve cell elongation compared with PLLA nanofibers. Our results showed that aligned PLLA/GT 75:25 nanofibers are promising substrates for application as bioengineered grafts for nerve tissue regeneration. PMID:26876833

  10. Hydroxyapatite-calcium sulfate-hyaluronic acid composite encapsulated with collagenase as bone substitute for alveolar bone regeneration.

    PubMed

    Subramaniam, Sadhasivam; Fang, Yen-Hsin; Sivasubramanian, Savitha; Lin, Feng-Huei; Lin, Chun-pin

    2016-01-01

    Periodontitis is a very severe inflammatory condition of the periodontium that progressively damages the soft tissue and destroys the alveolar bone that supports the teeth. The bone loss is naturally irreversible because of limited reparability of the teeth. Advancement in tissue engineering provides an effective regeneration of osseous defects with suitable dental implants or tissue-engineered constructs. This study reports a hydroxyapatite, calcium sulfate hemihydrate and hyaluronic acid laden collagenase (HAP/CS/HA-Col) as a bone substitute for the alveolar bone regeneration. The composite material was mechanically tested and the biocompatibility was evaluated by WST-1 assay. The in vivo bone formation was assessed in rat with alveolar bone defects and the bone augmentation by the HAP/CS/HA-Col composite was confirmed by micro-CT images and histological examination. The mechanical strength of 6.69 MPa with excellent biocompatibility was obtained for the HAP/CS/HA-Col composite. The collagenase release profile had facilitated the acceleration of bone remodeling process and it was confirmed by the findings of micro-CT and H&E staining. The bone defects implanted with HAP/CS/HA composite containing 2 mg/mL type I collagenase have shown improved new bone formation with matured bone morphology in comparison with the HAP/CS/HA composite that lacks the collagenase and the porous hydroxyapatite (p-HAP) granules. The said findings demonstrated that the collagenase inclusion in HAP/CS/HA composite is a feasible approach for the alveolar bone regeneration and the same design can also be applied to other defective tissues. PMID:26454048

  11. Mesoporous bioactive glass surface modified poly(lactic-co-glycolic acid) electrospun fibrous scaffold for bone regeneration.

    PubMed

    Chen, Shijie; Jian, Zhiyuan; Huang, Linsheng; Xu, Wei; Liu, Shaohua; Song, Dajiang; Wan, Zongmiao; Vaughn, Amanda; Zhan, Ruisen; Zhang, Chaoyue; Wu, Song; Hu, Minghua; Li, Jinsong

    2015-01-01

    A mesoporous bioactive glass (MBG) surface modified with poly(lactic-co-glycolic acid) (PLGA) electrospun fibrous scaffold for bone regeneration was prepared by dip-coating a PLGA electrospun fibrous scaffold into MBG precursor solution. Different surface structures and properties were acquired by different coating times. Surface morphology, chemical composition, microstructure, pore size distribution, and hydrophilicity of the PLGA-MBG scaffold were characterized. Results of scanning electron microscopy indicated that MBG surface coating made the scaffold rougher with the increase of MBG content. Scaffolds after MBG modification possessed mesoporous architecture on the surface. The measurements of the water contact angles suggested that the incorporation of MBG into the PLGA scaffold improved the surface hydrophilicity. An energy dispersive spectrometer evidenced that calcium-deficient carbonated hydroxyapatite formed on the PLGA-MBG scaffolds after a 7-day immersion in simulated body fluid. In vitro studies showed that the incorporation of MBG favored cell proliferation and osteogenic differentiation of human mesenchymal stem cells on the PLGA scaffolds. Moreover, the MBG surface-modified PLGA (PLGA-MBG) scaffolds were shown to be capable of providing the improved adsorption/release behaviors of bone morphogenetic protein-2 (BMP-2). It is very significant that PLGA-MBG scaffolds could be effective for BMP-2 delivery and bone regeneration. PMID:26082632

  12. Electrolytic regeneration of acid cupric chloride printed circuit board etchant. Final report, August 1, 1995--October 31, 1996

    SciTech Connect

    Oxley, J.E.; Smialek, R.J.

    1997-04-18

    The overall objective of this ERIP program was to make substantial progress in further developing a process for electrolytic regeneration of acid cupric chloride etchant - a process which was initially demonstrated in in-house studies and EPA Phase I and Phase II SBIRs. Specific objectives of the work were: (1) to define optimum system operating conditions by conducting a systematic study of process parameters, (2) to develop or find a superior electrolyic cell separator material, (3) to determine an optimum activation procedure for the flow-through carbon/graphite felt electrodes which are so critical to process performance, (4) to demonstrate - on the pre-prototype scale - electrolytic compensation for oxygen ingress - which causes etchant solution growth, and (5) to begin engineering design work on a prototype-scale regeneration unit. Parametric studies looked at the effect that key plating parameters have on copper deposit quality. Parameters tested included (a) velocity past the plating cathodes, (b) copper concentration in the catholyte solution from which the copper is being plated, (c) plating current density, and (d) catholyte cupric ion concentration. The most significant effects were obtained for velocity changes. The work showed that catholyte velocities above 0.5 ft/sec were needed to get adequate plating at 77.5 mA/cm{sup 2} and higher currents, and that even higher flow was better.

  13. Mesoporous bioactive glass surface modified poly(lactic-co-glycolic acid) electrospun fibrous scaffold for bone regeneration

    PubMed Central

    Chen, Shijie; Jian, Zhiyuan; Huang, Linsheng; Xu, Wei; Liu, Shaohua; Song, Dajiang; Wan, Zongmiao; Vaughn, Amanda; Zhan, Ruisen; Zhang, Chaoyue; Wu, Song; Hu, Minghua; Li, Jinsong

    2015-01-01

    A mesoporous bioactive glass (MBG) surface modified with poly(lactic-co-glycolic acid) (PLGA) electrospun fibrous scaffold for bone regeneration was prepared by dip-coating a PLGA electrospun fibrous scaffold into MBG precursor solution. Different surface structures and properties were acquired by different coating times. Surface morphology, chemical composition, microstructure, pore size distribution, and hydrophilicity of the PLGA-MBG scaffold were characterized. Results of scanning electron microscopy indicated that MBG surface coating made the scaffold rougher with the increase of MBG content. Scaffolds after MBG modification possessed mesoporous architecture on the surface. The measurements of the water contact angles suggested that the incorporation of MBG into the PLGA scaffold improved the surface hydrophilicity. An energy dispersive spectrometer evidenced that calcium-deficient carbonated hydroxyapatite formed on the PLGA-MBG scaffolds after a 7-day immersion in simulated body fluid. In vitro studies showed that the incorporation of MBG favored cell proliferation and osteogenic differentiation of human mesenchymal stem cells on the PLGA scaffolds. Moreover, the MBG surface-modified PLGA (PLGA-MBG) scaffolds were shown to be capable of providing the improved adsorption/release behaviors of bone morphogenetic protein-2 (BMP-2). It is very significant that PLGA-MBG scaffolds could be effective for BMP-2 delivery and bone regeneration. PMID:26082632

  14. Reduction in bile acid pool causes delayed liver regeneration accompanied by down-regulated expression of FXR and c-Jun mRNA in rats.

    PubMed

    Dong, Xiushan; Zhao, Haoliang; Ma, Xiaoming; Wang, Shiming

    2010-02-01

    The present study attempted to examine the effects of bile acid pool size on liver regeneration after hepatectomy. The rats were fed on 0.2% cholic acid (CA) or 2% cholestyramine for 7 days to induce a change in the bile acid size, and then a partial hepatectomy (PH) was performed. Rats fed on the normal diet served as the controls. Measurements were made on the rate of liver regeneration, the labeling indices of PCNA, the plasma total bile acids (TBA), and the mRNA expression of cholesterol 7alpha-hydroxylase (CYP7A1), farnesoid X receptor (FXR), and transcription factor c-Jun or c-fos. As compared with the normal and CA groups, the rate of liver regeneration was decreased on the day 3, and 7 after PH; the peak of the labeling indices of PCNA was delayed and the labeling indices were significantly reduced on the day 1; the TBA were also decreased on the day 1; the expression of FXR decreased but that of CYP7A1 increased at any given time; at the 1st, and 3rd h, the expression of c-Jun was declined in the cholestyramine group. The reduction in the bile acid pool size was found to delay the liver regeneration, which may be caused by the down-regulation of FXR and c-Jun expression. PMID:20155456

  15. In vitro regeneration and optimization of factors affecting Agrobacterium mediated transformation in Artemisia Pallens, an important medicinal plant.

    PubMed

    Alok, Anshu; Shukla, Vishnu; Pala, Zarna; Kumar, Jitesh; Kudale, Subhash; Desai, Neetin

    2016-04-01

    Artemisia pallens is an important medicinal plant. In-vitro regeneration and multiplication of A. pallens have been established using attached cotyledons. Different growth regulators were considered for regeneration of multiple shoots. An average of 36 shoots per explants were obtained by culturing attached cotyledons on Murashige and Skoog's medium containing 2 mg/L BAP and 0.1 mg/L NAA, after 45 days. The shoots were rooted best on half Murashige and Skoog's medium with respect to media containing 1 mg/L IBA or 1 mg/L NAA. Different parameters such as type of bacterial strains, OD600 of bacterial culture, co-cultivation duration, concentration of acetosyringone and explants type were optimized for transient expression of the reporter gene. Agrobacterium tumefaciens harbouring pCambia1301 plasmid carrying β-glucuronidase as a reporter gene and hygromycin phosphotransferase as plant selectable marker genes were used for genetic transformation of A. pallens. Hygromycin lethality test showed concentration of 15 mg/L were sufficient to inhibit the growth of attached cotyledons and multiple shoot buds of nontransgenics in selection media. Up to 83 % transient transformation was found when attached cotyledons were co-cultivated with Agrobacterium strain AGL1 for 2 days at 22 °C on shoot induction medium. The bacterial growth was eliminated by addition of cefotaxime (200 mg/L) in selection media. T0 transgenic plants were confirmed by GUS histochemical assay and further by polymerase chain reaction (PCR) using uidA and hpt gene specific primers. The study is useful in establishing technological improvement in A. pallens by genetic engineering. PMID:27436917

  16. Implications of microbiota and bile acid in liver injury and regeneration.

    PubMed

    Liu, Hui-Xin; Keane, Ryan; Sheng, Lili; Wan, Yu-Jui Yvonne

    2015-12-01

    Studies examining the mechanisms by which the liver incurs injury and then regenerates usually focus on factors and pathways directly within the liver, neglecting the signaling derived from the gut-liver axis. The intestinal content is rich in microorganisms as well as metabolites generated from both the host and colonizing bacteria. Through the gut-liver axis, this complex "soup" exerts an immense impact on liver integrity and function. This review article summarizes data published in the past 30 years demonstrating the signaling derived from the gut-liver axis in relation to liver injury and regeneration. Due to the intricate networks of implicated pathways as well as scarcity of available mechanistic data, it seems that nutrigenomic, metabolomics, and microbiota profiling approaches are warranted to provide a better understanding regarding the interplay and impact between nutrition, bacteria, and host response in influencing liver function and healing. Therefore elucidating the possible molecular mechanisms that link microbiota alteration to host physiological response and vice versa. PMID:26256437

  17. Role of TDZ in the quick regeneration of multiple shoots from nodal explant of Vitex trifolia L.--an important medicinal plant.

    PubMed

    Ahmed, Md Rafique; Anis, Mohammad

    2012-11-01

    The effect of thidiazuron (TDZ) has been investigated in shoot multiplication for a simple, efficient, rapid, and commercially applicable regeneration protocol of an important medicinal plant, Vitex trifolia. Multiple shoots were induced in nodal explants obtained from a mature tree on Murashige and Skoog (MS) medium supplemented with TDZ in various concentrations (0.5, 1.0, 2.5, 5.0, 7.5, or 10.0 μM). Prolonged exposure of the culture to TDZ had an adverse affect. To avoid this, the cultures were transferred to TDZ-free MS medium or MS medium fortified with various concentrations of 6-benzyladenine (BA) alone or in combination with α-naphthalene acetic acid (NAA) to enhance multiplication, proliferation, and elongation of induced shoots. Optimum shoot multiplication and elongation was achieved when TDZ-exposed explants were repeatedly subcultured on MS media containing a combination of 1.0 μM BA and 0.5 μM NAA. The highest shoot regeneration frequency (90 %) and maximum number (22.3 ± 0.2) of shoots per explant with shoot length of (5.2 ± 0.2 cm) was recorded on MS medium fortified with 5.0 μM TDZ. In vitro rooting of isolated shoots was achieved best in half-strength MS medium containing 0.5 μM NAA. Properly rooted plantlets were successfully hardened off and acclimatized in thermocol cups containing sterile Soilrite. These plantlets were then transferred to pots containing different potting substrate; percentage survival of the plantlets was highest in vermiculite/garden soil mixture (1:1) and successfully transfer to greenhouse under sunlight. PMID:23065400

  18. Insights into ascorbate regeneration in plants: investigating the redox and structural properties of dehydroascorbate reductases from Populus trichocarpa.

    PubMed

    Lallement, Pierre-Alexandre; Roret, Thomas; Tsan, Pascale; Gualberto, José M; Girardet, Jean-Michel; Didierjean, Claude; Rouhier, Nicolas; Hecker, Arnaud

    2016-03-15

    Dehydroascorbate reductases (DHARs), enzymes belonging to the GST superfamily, catalyse the GSH-dependent reduction of dehydroascorbate into ascorbate in plants. By maintaining a reduced ascorbate pool, they notably participate to H2O2 detoxification catalysed by ascorbate peroxidases (APXs). Despite this central role, the catalytic mechanism used by DHARs is still not well understood and there is no supportive 3D structure. In this context, we have performed a thorough biochemical and structural analysis of the three poplar DHARs and coupled this to the analysis of their transcript expression patterns and subcellular localizations. The transcripts for these genes are mainly detected in reproductive and green organs and the corresponding proteins are expressed in plastids, in the cytosol and in the nucleus, but not in mitochondria and peroxisomes where ascorbate regeneration is obviously necessary. Comparing the kinetic properties and the sensitivity to GSSG-mediated oxidation of DHAR2 and DHAR3A, exhibiting 1 or 3 cysteinyl residues respectively, we observed that the presence of additional cysteines in DHAR3A modifies the regeneration mechanism of the catalytic cysteine by forming different redox states. Finally, from the 3D structure of DHAR3A solved by NMR, we were able to map the residues important for the binding of both substrates (GSH and DHA), showing that DHAR active site is very selective for DHA recognition and providing further insights into the catalytic mechanism and the roles of the additional cysteines found in some DHARs. PMID:26699905

  19. Hyaluronic acid hydrogels with IKVAV peptides for tissue repair and axonal regeneration in an injured rat brain

    NASA Astrophysics Data System (ADS)

    Wei, Y. T.; Tian, W. M.; Yu, X.; Cui, F. Z.; Hou, S. P.; Xu, Q. Y.; Lee, In-Seop

    2007-09-01

    A biocompatible hydrogel of hyaluronic acid with the neurite-promoting peptide sequence of IKVAV was synthesized. The characterization of the hydrogel shows an open porous structure and a large surface area available for cell interaction. Its ability to promote tissue repair and axonal regeneration in the lesioned rat cerebrum is also evaluated. After implantation, the polymer hydrogel repaired the tissue defect and formed a permissive interface with the host tissue. Axonal growth occurred within the microstructure of the network. Within 6 weeks the polymer implant was invaded by host-derived tissue, glial cells, blood vessels and axons. Such a hydrogel matrix showed the properties of neuron conduction. It has the potential to repair tissue defects in the central nervous system by promoting the formation of a tissue matrix and axonal growth by replacing the lost tissue.

  20. Regeneration of Three-Way Automobile Catalysts using Biodegradable Metal Chelating Agent – S, S-Ethylenediamine Disuccinic Acid (S, S-EDDS)

    EPA Science Inventory

    Regeneration of the activity of three-way catalytic converters (TWCs) was tested for the first time using a biodegradable metal chelating agent (S, S. Ethylenediamine disuccinic acid (S, S-EDDS). The efficiency of this novel environmentally friendly solvent in removing various c...

  1. Regeneration of spent three-way catalysts with nano-structured platinum group metals by gas and acid treatments.

    PubMed

    Kim, Sang Chai; Nahm, Seung Won; Wang, Geun Shim; Seo, Seong Gyu; Lee, Jae Wook

    2008-10-01

    The influence of physicochemical treatments on the catalytic activity of the spent nano-structured three way catalysts (TWCs) was examined to evaluate the possibility of using spent TWCs for removing VOCs. Thermal gases and acid aqueous solutions were used to regenerate the spent nano-structured TWCs. The characterization of the spent catalyst and its modified forms was carried out by using XRD, TEM, ICP, and N2 adsorption-desorption isotherms. The catalytic activity tests revealed that the spent nano-structured TWCs have a great potential for removing toxic compounds. The activities of catalysts were also found to be highly dependent on the treatment conditions. The acid aqueous treatments were very useful for improving the catalytic activity because they removed various contaminants such as fuel additives, lubricant oil additives, and metallic compounds. However, the thermal gas treated TWCs were less active than the parent TWCs. Furthermore, the activities of the catalysts treated with acids were closely connected with the remaining Pt/Al ratios. PMID:19198464

  2. In situ forming hydrogels composed of oxidized high molecular weight hyaluronic acid and gelatin for nucleus pulposus regeneration.

    PubMed

    Chen, Yu-Chun; Su, Wen-Yu; Yang, Shu-Hua; Gefen, Amit; Lin, Feng-Huei

    2013-02-01

    Encapsulation of nucleus pulposus (NP) cells within in situ forming hydrogels is a novel biological treatment for early stage intervertebral disc degeneration. The procedure aims to prolong the life of the degenerating discs and to regenerate damaged tissue. In this study we developed an injectable oxidized hyaluronic acid-gelatin-adipic acid dihydrazide (oxi-HAG-ADH) hydrogel. High molecular weight (1900 kDa) hyaluronic acid was crosslinked with various concentrations of gelatin to synthesize the hydrogels and their viscoelastic properties were analyzed. Interactions between the hydrogels, NP cells, and the extracellular matrix (ECM) were also evaluated, as were the effects of the hydrogels on NP cell gene expression. The hydrogels possess several clinical advantages, including sterilizability, low viscosity for injection, and ease of use. The viscoelastic properties of the hydrogels were similar to native tissue, as reflected in the complex shear modulus (∼11-14 kPa for hydrogels, 11.3 kPa for native NP). Cultured NP cells not only attached to the hydrogels but also survived, proliferated, and maintained their round morphology. Importantly, we found that hydrogels increased NP cell expression of several crucial ECM-related genes, such as COL2A1, AGN, SOX-9, and HIF-1A. PMID:23041783

  3. In vitro bioactivity assessment of composite membrane containing antimicrobial lauric acid for guided bone regeneration in dental application

    NASA Astrophysics Data System (ADS)

    Suleiman, Muhammad Jabir; Kalitheertha, Jamuna Thevi; Sabri, Siti Noorzidah

    2015-07-01

    The manuscript reflect research work in fabrication of a triple layered composite membrane and to perform an in vitro bioactivity evaluation on composite membrane containing antimicrobial lauric acid. Poly(lactic-co-glycolic acid) (PLGA) matrix was incorporated with various amounts of nanoapatite (NAp) and lauric acid (LA) to form a triple-layered composite membrane. This membrane was prepared using a single step fabrication technique comprising of solvent casting, thermally induced phase separation and solvent leaching processes. Apatite mineralization was detected on the composite membranes within 30 days of exposure to simulated body fluid (SBF) and showed increased apatite formation at 30-60wt% of NAp content in the PLGA matrix on layer 3 (L3), that has the highest amount of NAp compared with layer 1 (L1) and layer 2 (L2) of the membrane. However, apatite mineralization was not detected on pure PLGA membrane. In addition, incorporation of LA on L1 and L2 has no influence on apatite mineral formation as none detected on these surfaces. The presence of NAp determines the formation of apatite crystals on the composite membrane. These membranes with triple layered design and bioactive properties showed potential use for guided bone regeneration purposes in dental application.

  4. Aminomethylphosphonic acid accumulation in plant species treated with glyphosate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. Greenhouse studies were conducted to determine the glyphosate I50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected legum...

  5. COLLABORATIVE EFFORT TO MODEL PLANT RESPONSE TO ACIDIC RAIN

    EPA Science Inventory

    Radish plants were exposed three times per week to simulated acidic rain at pH values of 2.6 to 5.4 over the course of four weeks in trials performed at Argonne, IL; Ithaca & Upton, NY; Corvallis, OR; Oak Ridge, TN; and Toronto, Canada. niform genotype, soil media and planting te...

  6. Increasing the Oleic Acid in Soybean Oil with Plant Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing the oleic acid content along with decrease in linolenic acid can improve the oxidative stability of soybean oil. Genetic changes in soybean using standard plant breeding practices has resulted in a publicly released a mid-oleic breeding line, N98-4445A, with oil that averages 57% oleic ac...

  7. Electrolytic recovery of copper and regeneration of nitric acid from a copper strip solution

    SciTech Connect

    Stewart, T.L.; Hartley, J.N.

    1985-01-01

    The fabrication of nuclear fuels involves stripping of a copper jacket with nitric acid. The waste acid, which contains 3.0 to 4.5 N nitric acid and 100 to 180 g/L copper, is currently discharged, neutralized, and disposed of in solar evaporation ponds. Alternative waste disposal and treatment methods including electrowinning are being investigated. Laboratory-scale electrowinning tests have been conducted in an air-sparged cell at current densities from 0.027 to 0.22 A/cm/sup 2/. The efficiency of copper recovery was improved by adding sulfamic acid or by cooling the electrolyte. Copper current efficiency ranged from 55% to 95%; energy consumption ranged from 1.8 to 6.6 kWh/kg Cu. Results of the laboratory-scale electrowinning tests are summarized. A brief economic comparison of an alternative waste disposal and acid recycle technique is presented.

  8. Screening of a broad range of rice (Oryza sativa L.) germplasm for in vitro rapid plant regeneration and development of an early prediction system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice has emerged as a model monocot for studies in agriculture and biotechnology, due to its relatively small genome and ready access to plant material. Tissue culture is one of the tools required for genetic transformation, for some breeding programs, and selection of high frequency regenerator ty...

  9. Agrobacterium tumefaciens-mediated transgenic plant and somaclone production through direct and indirect regeneration from leaves in Stevia rebaudiana with their glycoside profile.

    PubMed

    Khan, Shamshad Ahmad; Ur Rahman, Laiq; Shanker, Karuna; Singh, Manju

    2014-05-01

    Agrobacterium tumefaciens (EHA-105 harboring pCAMBIA 1304)-mediated transgenic plant production via direct regeneration from leaf and elite somaclones generation through indirect regeneration in Stevia rebaudiana is reported. Optimum direct regeneration frequency along with highest transformation frequency was found on MS + 1 mg/l BAP + 1 mg/l NAA, while indirect regeneration from callus was obtained on MS + 1 mg/l BAP + 2 mg/l NAA. Successful transfer of GUS-positive (GUS assay and PCR-based confirmation) transgenic as well as four somaclones up to glasshouse acclimatization has been achieved. Inter-simple sequence repeat (ISSR) profiling of transgenic and somaclonal plants showed a total of 113 bands, out of which 49 were monomorphic (43.36 %) and 64 were polymorphic (56.64 %). Transgenic plant was found to be closer to mother plant, while on the basis of steviol, stevioside, and rebaudioside A profile, somaclone S2 was found to be the best and showed maximum variability in ISSR profiling. PMID:24154495

  10. High Efficiency Somatic Embrogenesis and Plant Regeneration in Suspension Cultures of an Ornamental Ginger Hybrid (Hedychium muluense x cv ‘Starburst’)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants were successfully regenerated via somatic embryogenesis from shoot apex-derived callus of an ornamental ginger hybrid, Hedychium muluense x cv ‘Starburst’. H. muluense is a dwarf species and ‘Starburst’ is a hybrid cultivar with white and very fragrant flowers in a circular, wheel-like arrang...

  11. Transfer of resistance traits from carrot into tobacco by asymmetric somatic hybridization: Regeneration of fertile plants

    PubMed Central

    Dudits, Denes; Maroy, Eszter; Praznovszky, Tunde; Olah, Zoltan; Gyorgyey, Janos; Cella, Rino

    1987-01-01

    Transfer of methotrexate and 5-methyltryptophan resistance from carrot (Daucus carota) to tobacco (Nicotiana tabacum) was achieved by fusion between leaf mesophyll protoplasts of tobacco and irradiated cell culture protoplasts of carrot. Some of the regenerated somatic hybrids exhibited normal tobacco morphology with coexpression and independent segregation of the transferred resistance markers. Chromosomal instability resulted in aneuploid somatic hybrids with significantly lower chromosome number than predicted by simple addition of parental chromosome number. The methotrexate resistance phenotype was correlated with the expression of carrot-specific dihydrofolate reductase as judged by isozyme and immunological characteristics of the enzyme. The genomic construct of these somatic hybrids made the transmission of the resistance character into the next sexual generation possible. Images PMID:16593902

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

    NASA Astrophysics Data System (ADS)

    Sun, H. J.; Zhang, G.

    2011-12-01

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

  13. 9-Cis Retinoic Acid Promotes Lymphangiogenesis and Enhances Lymphatic Vessel Regeneration: Therapeutic Implications of 9-Cis Retinoic Acid for Secondary Lymphedema

    PubMed Central

    Choi, Inho; Lee, Sunju; Chung, Hee Kyoung; Lee, Yong Suk; Kim, Kyu Eui; Choi, Dongwon; Park, Eun Kyung; Yang, Dongyun; Ecoiffier, Tatiana; Monahan, John; Chen, Wen; Aguilar, Berenice; Lee, Ha Neul; Yoo, Jaehyuk; Koh, Chester J.; Chen, Lu; Wong, Alex K.; Hong, Young-Kwon

    2012-01-01

    Background The lymphatic system plays a key role in tissue fluid homeostasis and lymphatic dysfunction due to genetic defects or lymphatic vessel obstruction can cause lymphedema, disfiguring tissue swellings often associated with fibrosis and recurrent infections without available cures to date. In this study, retinoic acids (RAs) were determined to be a potent therapeutic agent that is immediately applicable to reduce secondary lymphedema. Methods and Results We report that RAs promote proliferation, migration and tube formation of cultured lymphatic endothelial cells (LECs) by activating FGF-receptor signaling. Moreover, RAs control the expression of cell-cycle checkpoint regulators such as p27Kip1, p57Kip2 and the aurora kinases through both an Akt-mediated non-genomic action and a transcription-dependent genomic action that is mediated by Prox1, a master regulator of lymphatic development. Moreover, 9-cisRA was found to activate in vivo lymphangiogenesis in animals based on mouse trachea, matrigel plug and cornea pocket assays. Finally, we demonstrate that 9-cisRA can provide a strong therapeutic efficacy in ameliorating the experimental mouse tail lymphedema by enhancing lymphatic vessel regeneration. Conclusions These in vitro and animal studies demonstrate that 9-cisRA potently activates lymphangiogenesis and promotes lymphatic regeneration in an experimental lymphedema model, presenting it as a promising novel therapeutic agent to treat human lymphedema patients. PMID:22275501

  14. Molecular Evolution of Plant AAP and LHT Amino Acid Transporters.

    PubMed

    Tegeder, Mechthild; Ward, John M

    2012-01-01

    Nitrogen is an essential mineral nutrient and it is often transported within living organisms in its reduced form, as amino acids. Transport of amino acids across cellular membranes requires proteins, and here we report the phylogenetic analysis across taxa of two amino acid transporter families, the amino acid permeases (AAPs) and the lysine-histidine-like transporters (LHTs). We found that the two transporter families form two distinct groups in plants supporting the concept that both are essential. AAP transporters seem to be restricted to land plants. They were found in Selaginella moellendorffii and Physcomitrella patens but not in Chlorophyte, Charophyte, or Rhodophyte algae. AAPs were strongly represented in vascular plants, consistent with their major function in phloem (vascular tissue) loading of amino acids for sink nitrogen supply. LHTs on the other hand appeared prior to land plants. LHTs were not found in chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean alga Klebsormidium flaccidum encodes KfLHT13 and phylogenetic analysis indicates that it is basal to land plant LHTs. This is consistent with the hypothesis that characean algae are ancestral to land plants. LHTs were also found in both S. moellendorffii and P. patens as well as in monocots and eudicots. To date, AAPs and LHTs have mainly been characterized in Arabidopsis (eudicots) and these studies provide clues to the functions of the newly identified homologs. PMID:22645574

  15. Molecular Evolution of Plant AAP and LHT Amino Acid Transporters

    PubMed Central

    Tegeder, Mechthild; Ward, John M.

    2012-01-01

    Nitrogen is an essential mineral nutrient and it is often transported within living organisms in its reduced form, as amino acids. Transport of amino acids across cellular membranes requires proteins, and here we report the phylogenetic analysis across taxa of two amino acid transporter families, the amino acid permeases (AAPs) and the lysine–histidine-like transporters (LHTs). We found that the two transporter families form two distinct groups in plants supporting the concept that both are essential. AAP transporters seem to be restricted to land plants. They were found in Selaginella moellendorffii and Physcomitrella patens but not in Chlorophyte, Charophyte, or Rhodophyte algae. AAPs were strongly represented in vascular plants, consistent with their major function in phloem (vascular tissue) loading of amino acids for sink nitrogen supply. LHTs on the other hand appeared prior to land plants. LHTs were not found in chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean alga Klebsormidium flaccidum encodes KfLHT13 and phylogenetic analysis indicates that it is basal to land plant LHTs. This is consistent with the hypothesis that characean algae are ancestral to land plants. LHTs were also found in both S. moellendorffii and P. patens as well as in monocots and eudicots. To date, AAPs and LHTs have mainly been characterized in Arabidopsis (eudicots) and these studies provide clues to the functions of the newly identified homologs. PMID:22645574

  16. Factors influencing plant regeneration from seedling explants of Hairy nightshade (Solanum sarrachoides)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A good model plant to investigate plant – pathogen interactions would be easy to grow, have a short life cycle, be a natural host of many pathogens, and be easy to manipulate genetically. Hairy nightshade (Solanum sarrachoides) is a ubiquitous, fast growing weed that produces copious amounts of see...

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

    SciTech Connect

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

    1989-01-01

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

  18. The Biosynthesis of δ-Aminolevulinic Acid in Higher Plants

    PubMed Central

    Beale, Samuel I.; Castelfranco, Paul A.

    1974-01-01

    δ-Aminolevulinic acid dehydrase activity in cucumber (Cucumis sativus L. var. Alpha green) cotyledons did not change as the tissue was allowed to green for 24 hours. δ-Aminolevulinic acid accumulated in greening cucumber cotyledons, and barley (Hordeum sativum L. var. Numar) and bean (Phaseolus vulgaris L. var. Red Kidney) leaves incubated in the presence of levulinic acid, a specific competitive inhibitor of δ-aminolevulinic acid dehydrase. The rate of δ-aminolevulinic acid accumulation in levulinic acid-treated cucumber cotyledons paralleled the rate of chlorophyll accumulation in the controls, and the quantity of δ-aminolevulinic acid accumulated compensated for the decrease in chlorophyll accumulation. When levulinic acid-treated cucumber cotyledons were returned to darkness, δ-aminolevulinic acid accumulation ceased. δ-Aminolevulinic acid accumulation showed an absolute requirement for oxygen and was inhibited drastically by cyanide and azide, and to a lesser extent by arsenite and malonate. 2,4-Dinitrophenol, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea, sodium fluoroacetate, and hydroxylamine hydrochloride showed no effect under the conditions tested. Freezing and thawing of the tissue completely prevented the accumulation of δ-aminolevulinic acid. The findings of this investigation are consistent with the hypothesis that δ-aminolevulinic acid is a chlorophyll precursor in higher plants, and that chlorophyll biosynthesis is regulated at the level of the formation of δ-aminolevulinic acid. PMID:16658693

  19. ACID/HEAVY METAL TOLERANT PLANTS

    EPA Science Inventory

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

  20. PLANT FATTY ACID (ETHANOL) AMIDE HYDROLASES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid amide hydrolase (FAAH) plays a central role in modulating endogenous N-acylethanolamine (NAE) levels in vertebrates, and, in part, constitutes an “endocannabinoid” signaling pathway that regulates diverse physiological and behavioral processes in animals. Recently, an Arabidopsis FAAH hom...

  1. Regeneration of self-compatible Pimpinella plants benefits from the addition of fly pollinators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Summary: The North Central Regional Plant Introduction Station (NCRPIS), located in Ames, Iowa maintains a large collection of diverse germplasm including 2276 accessions of Umbelliferae representing 43 genera. Although many Umbelliferae are insect pollinated, several species have a significant lev...

  2. Mechanically working fully-automatic plant for the regeneration of used aluminum cap screws for bottles

    NASA Astrophysics Data System (ADS)

    Schach, V.; Schach, H.

    1983-10-01

    A mechanical separation process for used aluminum cap screws for bottles is described. A prototype separation plant was developed and constructed. Test results indicate low energy consumption, no water pollution, and no emission of noxious vapors.

  3. Succession Influences Wild Bees in a Temperate Forest Landscape: The Value of Early Successional Stages in Naturally Regenerated and Planted Forests

    PubMed Central

    Taki, Hisatomo; Okochi, Isamu; Okabe, Kimiko; Inoue, Takenari; Goto, Hideaki; Matsumura, Takeshi; Makino, Shun'ichi

    2013-01-01

    In many temperate terrestrial forest ecosystems, both natural human disturbances drive the reestablishment of forests. Succession in plant communities, in addition to reforestation following the creation of open sites through harvesting or natural disturbances, can affect forest faunal assemblages. Wild bees perform an important ecosystem function in human-altered and natural or seminatural ecosystems, as they are essential pollinators for both crops and wild flowering plants. To maintain high abundance and species richness for pollination services, it is important to conserve and create seminatural and natural land cover with optimal successional stages for wild bees. We examined the effects of forest succession on wild bees. In particular, we evaluated the importance of early successional stages for bees, which has been suspected but not previously demonstrated. A range of successional stages, between 1 and 178 years old, were examined in naturally regenerated and planted forests. In total 4465 wild bee individuals, representing 113 species, were captured. Results for total bees, solitary bees, and cleptoparasitic bees in both naturally regenerated and planted conifer forests indicated a higher abundance and species richness in the early successional stages. However, higher abundance and species richness of social bees in naturally regenerated forest were observed as the successional stages progressed, whereas the abundance of social bees in conifer planted forest showed a concave-shaped relationship when plotted. The results suggest that early successional stages of both naturally regenerated and conifer planted forest maintain a high abundance and species richness of solitary bees and their cleptoparasitic bees, although social bees respond differently in the early successional stages. This may imply that, in some cases, active forest stand management policies, such as the clear-cutting of planted forests for timber production, would create early successional

  4. Biosynthesis of Jasmonic Acid by Several Plant Species 1

    PubMed Central

    Vick, Brady A.; Zimmerman, Don C.

    1984-01-01

    Six plant species metabolized 18O-labeled 12-oxo-cis,cis-10,15-phytodienoic acid (12-oxo-PDA) to short chain cyclic fatty acids. The plant species were corn (Zea mays L.), eggplant (Solanum melongena L.), flax (Linum usitatissimum L.), oat (Avena sativa L.), sunflower (Helianthus annuus L.), and wheat (Triticum aestivum L.). Among the products was jasmonic acid, a natural plant constituent with growth-regulating properties. The pathway is the same as the one recently reported by us for jasmonic acid synthesis in Vicia faba L. pericarp. First, the ring double bond of 12-oxo-PDA is saturated; then β-oxidation enzymes remove six carbons from the carboxyl side chain of the ring. Substrate specificity studies indicated that neither the stereochemistry of the side chain at carbon 13 of 12-oxo-PDA nor the presence of the double bond at carbon 15 was crucial for either enzyme step. The presence of enzymes which convert 12-oxo-PDA to jasmonic acid in several plant species indicates that this may be a general metabolic pathway in plants. PMID:16663643

  5. Microbial Products Trigger Amino Acid Exudation from Plant Roots1

    PubMed Central

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

    2004-01-01

    Plants naturally cycle amino acids across root cell plasma membranes, and any net efflux is termed exudation. The dominant ecological view is that microorganisms and roots passively compete for amino acids in the soil solution, yet the innate capacity of roots to recover amino acids present in ecologically relevant concentrations is unknown. We find that, in the absence of culturable microorganisms, the influx rates of 16 amino acids (each supplied at 2.5 μm) exceed efflux rates by 5% to 545% in roots of alfalfa (Medicago sativa), Medicago truncatula, maize (Zea mays), and wheat (Triticum aestivum). Several microbial products, which are produced by common soil microorganisms such as Pseudomonas bacteria and Fusarium fungi, significantly enhanced the net efflux (i.e. exudation) of amino acids from roots of these four plant species. In alfalfa, treating roots with 200 μm phenazine, 2,4-diacetylphloroglucinol, or zearalenone increased total net efflux of 16 amino acids 200% to 2,600% in 3 h. Data from 15N tests suggest that 2,4-diacetylphloroglucinol blocks amino acid uptake, whereas zearalenone enhances efflux. Thus, amino acid exudation under normal conditions is a phenomenon that probably reflects both active manipulation and passive uptake by microorganisms, as well as diffusion and adsorption to soil, all of which help overcome the innate capacity of plant roots to reabsorb amino acids. The importance of identifying potential enhancers of root exudation lies in understanding that such compounds may represent regulatory linkages between the larger soil food web and the internal carbon metabolism of the plant. PMID:15347793

  6. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters

    SciTech Connect

    Poole, L.J.; King, C.J.

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration

  7. Insect Pollination in the Regeneration of Germplasm at the Western Regional Plant Introduction Station

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollination research at the USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington, has identified the best and most cost effective fly pollinators for field cage pollination of Allium and Lesquerella accessions. The bottle fly, Calliphora vicina, was superior to house fly, Musca...

  8. Uranium from phosphoric acid: IMC`s Uncle Sam Plant

    SciTech Connect

    1994-02-01

    This article discusses uranium recovery from phosphoric acid, proven to be a viable technology by several U.S. producers since 1978. This technology has accounted for 12.8% of U.S. uranium production during this time: a total of almost 40 Mlb equivalent U3O8. Of the several producers, only the Uncle Sam plant of IMC-Agrico has operated continuously during the period, and that plant is the longest-lived uranium production facility operating in the United States. The basis for the process is reviewed, including geological aspects, mining and recovery of phosphorite, phosphoric acid production, and uranium recovery. Licensing of such facilities is also discussed.

  9. Collaborative effort to model plant response to acidic rain

    SciTech Connect

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

    1988-06-01

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

  10. Plant-mediated stereoselective biotransformation of phenylglyoxylic acid esters.

    PubMed

    Maczka, Wanda Krystyna; Grabarczyk, Małgorzata; Wińska, Katarzyna; Anioł, Mirosław

    2014-01-01

    Enantioselective reduction of the carbonyl group of three phenylglyoxylic acid esters (methyl, ethyl, and n-propyl esters, 2-4) was conducted using blended plant materials (roots of carrot, beetroot, celeriac and parsley; apple). All used biocatalysts transformed these esters to the corresponding mandelic acid esters with high yield, preferably into the respective R-enantiomer. Butanedione addition improved the enantioselectivity of the reaction. PMID:25265851

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

    DOEpatents

    Somerville, C.; Loo, F. van de

    1997-09-16

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

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

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    1997-01-01

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

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

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    2002-01-01

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

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

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    1998-01-01

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

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

    DOEpatents

    Somerville, C.; Loo, F. van de

    1998-09-01

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

  16. Somatic embryogenesis and plant regeneration in tissue cultures of radish (Raphanus sativus L.).

    PubMed

    Jeong, W J; Min, S R; Liu, J R

    1995-07-01

    Hypocotyl segments of 2- to 3-week-old radish (Raphanus sativus L. cv. F1 Handsome Fall) seedlings produced yellowish compact calli when cultured on Murashige and Skoog's (MS) medium supplemented with 1 mgl(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). Upon transfer onto medium containing 6-benzyladenine and α-naphthaleneacetic acid, up to 5.3% of the calli gave rise to a few somatic embryos. When subcultured for 3 to 6 months, 7% of the yellowish, compact calli produced white, compact calli which formed numerous embryos. These calli maintained their embryogenic capacity for over 18 months. When cultured on medium containing 0.1 to 3 mgl(-1) 2,4-D, up to 90% of longitudinally sliced somatic embryo halves produced calli with numerous secondary embryos. Embryos were transferred onto medium containing 0.1 mgl(-1) 2,4-D and 1 mgl(-1) abscisic acid where they developed into the cotyledonary stage. Upon transfer onto half-strength MS basal medium, approximately 90% of the embryos developed into plantlets. These plantlets were successfully transplanted in potting soil and after cold treatment they were grown to maturity in a phytotron. PMID:24194314

  17. Triple-layered PLGA/nanoapatite/lauric acid graded composite membrane for periodontal guided bone regeneration.

    PubMed

    Jamuna-Thevi, Kalitheertha; Saarani, Nur Najiha; Abdul Kadir, Mohamed Rafiq; Hermawan, Hendra

    2014-10-01

    This paper discusses the successful fabrication of a novel triple-layered poly(lactic-co-glycolic acid) (PLGA)-based composite membrane using only a single step that combines the techniques of solvent casting and thermally induced phase separation/solvent leaching. The resulting graded membrane consists of a small pore size layer-1 containing 10 wt% non-stoichiometric nanoapatite (NAp)+1-3 wt% lauric acid (LA) for fibroblastic cell and bacterial inhibition, an intermediate layer-2 with 20-50 wt% NAp+1 wt% LA, and a large pore size layer-3 containing 30-100 wt% NAp without LA to allow bone cell growth. The synergic effects of 10-30 wt% NAp and 1 wt% LA in the membrane demonstrated higher tensile strength (0.61 MPa) and a more elastic behavior (16.1% elongation at break) in 3 wt% LA added membrane compared with the pure PLGA (0.49 MPa, 9.1%). The addition of LA resulted in a remarkable plasticizing effect on PLGA at 3 wt% due to weak intermolecular interactions in PLGA. The pure and composite PLGA membranes had good cell viability toward human skin fibroblast, regardless of LA and NAp contents. PMID:25175212

  18. Investigation of emulsified, acid and acid-alkali catalyzed mesoporous bioactive glass microspheres for bone regeneration and drug delivery.

    PubMed

    Miao, Guohou; Chen, Xiaofeng; Dong, Hua; Fang, Liming; Mao, Cong; Li, Yuli; Li, Zhengmao; Hu, Qing

    2013-10-01

    Acid-catalyzed mesoporous bioactive glass microspheres (MBGMs-A) and acid-alkali co-catalyzed mesoporous bioactive glass microspheres (MBGMs-B) were successfully synthesized via combination of sol-gel and water-in-oil (W/O) micro-emulsion methods. The structural, morphological and textural properties of mesoporous bioactive glass microspheres (MBGMs) were characterized by various techniques. Results show that both MBGMs-A and MBGMs-B exhibit regularly spherical shape but with different internal porous structures, i.e., a dense microstructure for MBGMs-A and internally porous structure for MBGMs-B. (29)Si NMR data reveal that MGBMs have low polymerization degree of silica network. The in vitro bioactivity tests indicate that the apatite formation rate of MBGMs-B was faster than that of MBGMs-A after soaking in simulated body fluid (SBF) solution. Furthermore, the two kinds of MBGMs have similar storage capacity of alendronate (AL), and the release behaviors of AL could be controlled due to their unique porous structure. In conclusion, the microspheres are shown to be promising candidates as bone-related drug carriers and filling materials of composite scaffold for bone repair. PMID:23910338

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

    PubMed Central

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

    2014-01-01

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

  20. Plant regeneration from seeds responds to phylogenetic relatedness and local adaptation in Mediterranean Romulea (Iridaceae) species.

    PubMed

    Carta, Angelino; Hanson, Sarah; Müller, Jonas V

    2016-06-01

    Seed germination is the most important transitional event between early stages in the life cycle of spermatophytes and understanding it is crucial to understand plant adaptation and evolution. However, so far seed germination of phylogenetically closely related species has been poorly investigated. To test the hypothises that phylogenetically related plant species have similar seed ecophysiological traits thereby reflecting certain habitat conditions as a result of local adaptation, we studied seed dormancy and germination in seven Mediterranean species in the genus Romulea (Iridaceae). Both the across-species model and the model accounting for shared evolutionary history showed that cool temperatures (≤ 15°C) were the main factor that promoted seed germination. The absence of embryo growth before radicle emergence is consistent with a prompt germination response at cool temperatures. The range of temperature conditions for germination became wider after a period of warm stratification, denoting a weak primary dormancy. Altogether these results indicate that the studied species exhibit a Mediterranean germination syndrome, but with species-specific germination requirements clustered in a way that follows the phylogenetic relatedness among those species. In addition, species with heavier seeds from humid habitats showed a wider range of conditions for germination at dispersal time than species from dry habitats possessing lighter seeds. We conclude that while phylogenetically related species showed very similar germination requirements, there are subtle ecologically meaningful differences, confirming the onset of adaptation to local ecological factors mediated by species relatedness. PMID:27516872

  1. Cryopreservation of Passiflora pohlii nodal segments and assessment of genetic stability of regenerated plants.

    PubMed

    Merhy, T S M; Vianna, M G; Garcia, R O; Pacheco, G; Mansur, E

    2014-01-01

    Passiflora pohlii is a wild species native to Brazil, with a potential agronomic interest due to its tolerance to soil-borne pathogens that cause damage to the passion fruit culture, and could be used in breeding. Because this species occurs in impacted regions, the goal of this study was the development of in vitro conservation strategies, using nodal segments from axenic plants. Encapsulation-vitrification and vitrification techniques were tested for cryopreservation of nodal segments. The highest recovery (65%) was obtained with the vitrification technique using treatment with the PVS3 vitrification solution from 30 to 120 min. Post-rewarming recovery was achieved on MSM medium supplemented with 30.8 μM BAP with incubation in the dark for 30 days before transfer in the presence of light. No differences were detected between control and cryopreserved materials as assayed by RAPD and ISSR. PMID:24997838

  2. Plant regeneration from encapsulated embryoids and an embryogenic mass of pistachio, Pistacia vera L.

    PubMed

    Onay, A; Jeffree, C E; Yeoman, M M

    1996-05-01

    Pieces of an embryogenic mass (EMS) induced in culture from immature fruits of pistachio, Pistacia vera L., were encapsulated into calcium alginate beads. Somatic embryos were also encapsulated individually into calcium alginate beads to produce synthetic seeds. The viability of the encapsulated EMS and somatic embryos was investigated immediately following encapsulation, and after storage for 60 days at 4°C. The encapsulated-stored EMS fragments recovered their original proliferative capacity after two months storage following two sub-cultures, but non-encapsulated-stored EMS failed to recover. The conversion frequency of synthetic seeds to seedling plants was 14% after storage for 60 days at 4°C, from which it may be concluded that encapsulation is a practical procedure for short-term storage of embryogenic pistachio tissue, and may be applicable to the preservation of desirable elite genotypes. PMID:24178619

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

    NASA Astrophysics Data System (ADS)

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

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

  4. Efficient in vitro direct shoot organogenesis and regeneration of fertile plants from embryo explants of Bambara groundnut ( Vigna subterranea L. Verdc.).

    PubMed

    Lacroix, B; Assoumou, Y; Sangwan, R S

    2003-08-01

    An efficient protocol has been developed for direct shoot organogenesis from embryo axes derived from mature seeds of two different landraces of Bambara groundnut. Multiple shoots were initiated on several media containing different concentrations and combinations of benzylaminopurine (BAP) or thidiazuron (TDZ). Efficient regeneration occurred when the embryo axes were first plated for 6 days on a medium containing high concentrations of BAP (1 mg/l) and alpha-naphthaleneacetic acid (NAA, 1 mg/l) and then cut transversely and transferred onto a medium containing 1.5 mg/l BAP. Shoot regeneration frequency was 100% and from five to eight shoots per explant were obtained. The importance of using embryo explants and cytokinins in the culture media, with respect to controlling the development of a highly organogenic system, was demonstrated. Histological studies revealed that proliferating buds originated directly from the superficial layers of the explants without an intermediate callus phase. The regenerated shoots were rooted on a medium containing 1 mg/l NAA and then transferred to the greenhouse. Flow cytometric analyses and chloroplast counts of guard cells suggested that the regenerants were diploid. All were morphologically normal and fertile. The short duration, high efficiency and low frequency of somaclonal variation of this system make it well suited for wider biotechnological applications of Bambara groundnut-a neglected and under-utilized crop. PMID:12910367

  5. Regeneration inducers in limb regeneration.

    PubMed

    Satoh, Akira; Mitogawa, Kazumasa; Makanae, Aki

    2015-08-01

    Limb regeneration ability, which can be observed in amphibians, has been investigated as a representative phenomenon of organ regeneration. Recently, an alternative experimental system called the accessory limb model was developed to investigate early regulation of amphibian limb regeneration. The accessory limb model contributed to identification of limb regeneration inducers in urodele amphibians. Furthermore, the accessory limb model may be applied to other species to explore universality of regeneration mechanisms. This review aims to connect the insights recently gained to emboss universality of regeneration mechanisms among species. The defined molecules (BMP7 (or2) + FGF2 + FGF8) can transform skin wound healing to organ (limb) regeneration responses. The same molecules can initiate regeneration responses in some species. PMID:26100345

  6. Probing interactions between plant virus movement proteins and nucleic acids.

    PubMed

    Tzfira, Tzvi; Citovsky, Vitaly

    2008-01-01

    Most plant viruses move between plant cells with the help of their movement proteins (MPs). MPs are multifunctional proteins, and one of their functions is almost invariably binding to nucleic acids. Presumably, the MP-nucleic acid interaction is directly involved in formation of nucleoprotein complexes that function as intermediates in the cell-to-cell transport of many plant viruses. Thus, when studying a viral MP, it is important to determine whether or not it binds nucleic acids, and to characterize the hallmark parameters of such binding, i.e., preference for single- or double-stranded nucleic acids and binding cooperativity and sequence specificity. Here, we present two major experimental approaches, native gel mobility shift assay and ultra violet (UV) light cross-linking, for detection and characterization of MP binding to DNA and RNA molecules. We also describe protocols for purification of recombinant viral MPs over-expressed in bacteria and production of different DNA and RNA probes for these binding assays. PMID:18370264

  7. Extensive cell migration, axon regeneration and improved function with polysialic acid-modified Schwann cells after spinal cord injury

    PubMed Central

    Ghosh, Mousumi; Tuesta, Luis M.; Puentes, Rocio; Patel, Samik; Melendez, Kiara; Maarouf, Abderrahman El; Rutishauser, Urs; Pearse, Damien Daniel

    2015-01-01

    Schwann cells (SC) implantation after spinal cord injury (SCI) promotes axonal regeneration, remyelination repair and functional recovery. Reparative efficacy, however, may be limited due to the inability of SCs to migrate outward from the lesion-implant site. Altering SC cell surface properties by over-expressing polysialic acid (PSA) has been shown to promote SC migration. In the current study, a SCI contusion was used to evaluate the migration, supraspinal axon growth support and functional recovery associated with polysialyltransferase (PST)-over-expressing SCs (PST-GFP SCs) or controls (GFP SCs). Compared to GFP SCs, which remained confined to the injection site at the injury center, PST-GFP SCs migrated across the lesion:host cord interface for distances of up to 4.4 mm within adjacent host tissue. In addition, with PST-GFP SCs, there was extensive serotonergic and corticospinal axon in-growth within the implants that was limited in the GFP SC controls. The enhanced migration of PST-GFP SCs was accompanied by significant growth of these axons caudal to lesion. Animals receiving PST-GFP SCs exhibited improved functional outcome, both in the open-field and on the gridwalk test, over modest improvements provided by GFP SC controls. The current study for the first time demonstrates that a lack of migration by SC may hinder their reparative benefits and that cell surface overexpression of PSA enhances the ability of implanted SCs to associate with and support the growth of corticospinal axons. These results provide further promise that PSA modified SCs will be a potent reparative approach for SCI. PMID:22460918

  8. Extensive cell migration, axon regeneration, and improved function with polysialic acid-modified Schwann cells after spinal cord injury.

    PubMed

    Ghosh, Mousumi; Tuesta, Luis M; Puentes, Rocio; Patel, Samik; Melendez, Kiara; El Maarouf, Abderrahman; Rutishauser, Urs; Pearse, Damien Daniel

    2012-05-01

    Schwann cell (SC) implantation after spinal cord injury (SCI) promotes axonal regeneration, remyelination repair, and functional recovery. Reparative efficacy, however, may be limited because of the inability of SCs to migrate outward from the lesion-implant site. Altering SC cell surface properties by overexpressing polysialic acid (PSA) has been shown to promote SC migration. In this study, a SCI contusion model was used to evaluate the migration, supraspinal axon growth support, and functional recovery associated with polysialyltransferase (PST)-overexpressing SCs [PST-green fluorescent protein (GFP) SCs] or controls (GFP SCs). Compared with GFP SCs, which remained confined to the injection site at the injury center, PST-GFP SCs migrated across the lesion:host cord interface for distances of up to 4.4 mm within adjacent host tissue. In addition, with PST-GFP SCs, there was extensive serotonergic and corticospinal axon in-growth within the implants that was limited in the GFP SC controls. The enhanced migration of PST-GFP SCs was accompanied by significant growth of these axons caudal to lesion. Animals receiving PST-GFP SCs exhibited improved functional outcome, both in the open-field and on the gridwalk test, beyond the modest improvements provided by GFP SC controls. This study for the first time demonstrates that a lack of migration by SCs may hinder their reparative benefits and that cell surface overexpression of PSA enhances the ability of implanted SCs to associate with and support the growth of corticospinal axons. These results provide further promise that PSA-modified SCs will be a potent reparative approach for SCI. © 2012 Wiley Periodicals, Inc. PMID:22460918

  9. In vitro and in vivo bioactivity assessment of a polylactic acid/hydroxyapatite composite for bone regeneration

    PubMed Central

    Danoux, Charlène B; Barbieri, Davide; Yuan, Huipin; de Bruijn, Joost D; van Blitterswijk, Clemens A; Habibovic, Pamela

    2014-01-01

    Synthetic bone graft substitutes based on composites consisting of a polymer and a calcium-phosphate (CaP) ceramic are developed with the aim to satisfy both mechanical and bioactivity requirements for successful bone regeneration. In the present study, we have employed extrusion to produce a composite consisting of 50 wt.% poly(D,L-lactic acid) (PLA) and 50 wt.% nano-sized hydroxyapatite (HA) powder, achieving homogeneous distribution of the ceramic within the polymeric phase. In vitro, in both a simulated physiological saline (SPS) and a simulated body fluid (SBF), a greater weight loss was observed for PLA/HA than for PLA particles upon 12-week immersion. Furthermore, in SPS, a continuous release of calcium and phosphate from the composite was measured, whereas in SBF, decrease of the amount of the two ions in the solution was observed both for PLA and PLA/HA accompanied with the formation of a CaP layer on the surface. In vitro characterization of the composite bioactivity was performed by culturing human mesenchymal stromal cells (hMSCs) and assessing proliferation and osteogenic differentiation, with PLA as a control. Both PLA/HA composite and PLA control were shown to support hMSCs proliferation over a period of two weeks. In addition, the composite significantly enhanced alkaline phosphatase (ALP) activity of hMSCs in osteogenic medium as compared with the polymer control. A novel implant design was employed to develop implants from dense, extruded materials, suitable for testing osteoinductivity in vivo. In a preliminary study in dogs, PLA/HA composite implants induced heterotopic bone formation upon 12-week intramuscular implantation in all animals, in contrast to PLA control, which was not osteoinductive. Unlike in vitro, a more pronounced degradation of PLA was observed in vivo as compared with PLA/HA composite. PMID:24441389

  10. In vitro and in vivo bioactivity assessment of a polylactic acid/hydroxyapatite composite for bone regeneration.

    PubMed

    Danoux, Charlène B; Barbieri, Davide; Yuan, Huipin; de Bruijn, Joost D; van Blitterswijk, Clemens A; Habibovic, Pamela

    2014-01-01

    Synthetic bone graft substitutes based on composites consisting of a polymer and a calcium-phosphate (CaP) ceramic are developed with the aim to satisfy both mechanical and bioactivity requirements for successful bone regeneration. In the present study, we have employed extrusion to produce a composite consisting of 50 wt.% poly(D,L-lactic acid) (PLA) and 50 wt.% nano-sized hydroxyapatite (HA) powder, achieving homogeneous distribution of the ceramic within the polymeric phase. In vitro, in both a simulated physiological saline (SPS) and a simulated body fluid (SBF), a greater weight loss was observed for PLA/HA than for PLA particles upon 12-week immersion. Furthermore, in SPS, a continuous release of calcium and phosphate from the composite was measured, whereas in SBF, decrease of the amount of the two ions in the solution was observed both for PLA and PLA/HA accompanied with the formation of a CaP layer on the surface. In vitro characterization of the composite bioactivity was performed by culturing human mesenchymal stromal cells (hMSCs) and assessing proliferation and osteogenic differentiation, with PLA as a control. Both PLA/HA composite and PLA control were shown to support hMSCs proliferation over a period of two weeks. In addition, the composite significantly enhanced alkaline phosphatase (ALP) activity of hMSCs in osteogenic medium as compared with the polymer control. A novel implant design was employed to develop implants from dense, extruded materials, suitable for testing osteoinductivity in vivo. In a preliminary study in dogs, PLA/HA composite implants induced heterotopic bone formation upon 12-week intramuscular implantation in all animals, in contrast to PLA control, which was not osteoinductive. Unlike in vitro, a more pronounced degradation of PLA was observed in vivo as compared with PLA/HA composite. PMID:24441389

  11. Extraction of Nucleic Acids from Lyophilized Plant Material

    PubMed Central

    Guinn, Gene

    1966-01-01

    Four methods for extracting nucleic acids from lyophilized cotton (Gossypium hirsutum L. cv. Stoneville 62) leaves and roots were compared. They were based on the use of: (I) HC104; (II) KOH; (III) a mixture of 90% phenol, Tris (hydroxymethyl) aminomethane buffer, and sodium lauryl sulfate; and (IV) NaCl. (I) extracted large amounts of RNA but little DNA and extracted much carbohydrate and protein contaminants. (II) gave a good yield of both RNA and DNA but extracted such large amounts of contaminating material that purification of RNA on an anion exchange column was necessary. (III) extracted only part of the RNA and practically no DNA, but extracted contaminating materials. (IV) resulted in high yields of both RNA and DNA when modified to omit preliminary acid extraction of impurities. The use of cold trichloroacetic acid instead of ethanol, to precipitate NaCl-extracted nucleic acids, separated the nucleic acids from most of the carbohydrate and acid-soluble phosphate contaminants and resulted in good agreement among results by ultraviolet absorbance, pentose tests, and phosphate analysis. This method also resulted in lower protein contents and better ultraviolet absorption spectra than the other methods tested. Nucleic acids were extracted from leaves of 14 other species of plants, in addition to cotton, by this modified NaCl procedure. PMID:16656306

  12. Abscisic acid signaling through cyclic ADP-ribose in plants

    SciTech Connect

    Wu, Yan; Kuzma, J.; Marechal, E.

    1997-12-19

    Abscisic acid (ABA) is the primary hormone that mediates plant responses to stresses such as cold, drought, and salinity. Single-cell microinjection experiments in tomato were used to identify possible intermediates involved in ABA signal transduction. Cyclic ADP-ribose (cADPR) was identified as a signaling molecule in the ABA response and was shown to exert its effects by way of calcium. Bioassay experiments showed that the amounts of cADPR in Arabidopsis thaliana plants increased in response to ABA treatment and before ABA-induced gene expression.

  13. Fabrication and characterization of cross-linkable hydrogel particles based on hyaluronic acid: potential application in vocal fold regeneration.

    PubMed

    Sahiner, Nurettin; Jha, Amit K; Nguyen, David; Jia, Xinqiao

    2008-01-01

    There is a critical need to engineer hyaluronic acid (HA)-based hydrogels with prolonged in vivo residence time, temporal release of therapeutics and matching viscoelasticity for use in vocal fold tissue engineering. We have previously demonstrated the synthesis and characterization of HA-based soft hydrogel particles (HGP) and particle cross-linked networks as injectable materials to treat vocal fold scarring. In this paper, we report a more versatile technique for preparing cross-linkable HA HGP with reduced sizes. HA HGP were synthesized via chemical cross-linking with divinyl sulfone using a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane reverse micelle system in the presence of 1-heptanol. These HGP were rendered cross-linkable by introducing aldehyde groups via sodium periodate oxidation (oxHGP). The presence of aldehyde groups was confirmed by multi-photon confocal microscope upon fluorescence staining using cascade blue hydrazide. The aldehyde groups were used as reactive handles for covalent cross-linking with HA that has been previously modified with adipic acid dihydrazide (HADH). The resulting doubly cross-linked networks (DXN) are highly pliable and do not break until approx. 200-300% strain. The measured elastic modulus of the DXN is around 500 Pa, while the dynamic viscosity decreases linearly with frequency in log- log scale. The mechanical characteristics of DXN are similar to that of vocal fold lamina propria. In vitro cell-proliferation assays showed that the cross-linkable HA HGP did not adversely affect the proliferation of the cultured fibroblasts as assessed by MTT assay. A low-molecular-weight model drug, rhodamine 6G (R6G), was loaded into oxHGP, and its release was monitored using UV-Vis spectroscopy. R6G-loaded oxHGP maintained their ability to form DXN when mixed with the HAADH solution. Approximately 84% of entrapped R6G was liberated from oxHGP at a rate of 0.24%/min in the first 6 h. When encapsulated in the DXN, R6G was

  14. Effects of climate warming on plant autotoxicity in forest evolution: a case simulation analysis for Picea schrenkiana regeneration.

    PubMed

    Ruan, Xiao; Pan, Cun-De; Liu, Run; Li, Zhao-Hui; Li, Shu-Ling; Jiang, De-An; Zhang, Jing-Chi; Wang, Geoff; Zhao, Yin-Xian; Wang, Qiang

    2016-08-01

    In order to explore how plant autotoxicity changes with climate warming, the autotoxicity of P. schrenkiana needles' water extract, organic extract fractions, and key allelochemical DHAP was systemically investigated at the temperature rising 2 and 4°C based on the data-monitored soil temperature during the last decade in the stage of Schrenk spruce regeneration (seed germination and seedling growth). The results showed that the criterion day and night temperatures were 12°C and 4°C for seed germination, and 14°C and 6°C for seedling growth, respectively. In the presence of water extract, the temperature rise of 2°C significantly inhibited the germination vigor and rate of P. Schrenkiana seed, and a temperature rise of 4°C significantly increased the inhibition to the seedling growth (P < 0.05). Among the three organic fractions, the low-polar fraction showed to be more phytotoxic than the other two fractions, causing significant inhibitory effects on the seed germination and growth even at low concentration of 0.1 mg/mL, and the inhibition effect was enhanced as temperature increased. The temperature rise significantly enhanced the promotion effect of DHAP, while the inhibition effect of temperature rise became less important with increasing concentration of DHAP. This investigation revealed that autotoxicity of P. schrenkiana was affected by the climate warming. As expected, it provided an insight into the mechanism and effectiveness of allelopathy in bridging the causal relationship between forest evolution and climate warming. PMID:27547360

  15. Induction of 12-oxo-phytodienoic acid in wounded plants and elicited plant cell cultures.

    PubMed Central

    Parchmann, S; Gundlach, H; Mueller, M J

    1997-01-01

    Jasmonic acid (JA) is rapidly biosynthesized from alpha-linolenic acid in plants upon contact with pathogens or wounding, and triggers gene activation, leading to the synthesis of defensive secondary metabolites and proteins. Despite the recent finding that its precursor, 12-oxo-phytodienoic acid (PDA), is a more powerful inducer of gene activation, interest has focused so far almost exclusively on JA. A validated negative chemical ionization-gas chromatography-mass spectrometry method has been developed that allows the simultaneous quantification of endogenous 12-oxo-PDA and JA in plant tissues. In six out of eight plant species tested maximal levels of 12-oxo-PDA exceeded peak levels of JA by approximately 3- to 5-fold after elicitation with a yeast cell wall preparation or when plants were wounded. These experiments support the hypothesis that 12-oxo-PDA acts as the predominant jasmonate signal in most plants, whereas JA remains an active metabolite of its precursor. Furthermore, JA but not 12-oxo-PDA was shown to be secreted into the medium from cultured plant cells, suggesting that JA may also act as an intercellular signal. PMID:9390438

  16. Expanding the docosahexaenoic acid food web for sustainable production: engineering lower plant pathways into higher plants

    PubMed Central

    Petrie, James R.; Singh, Surinder P.

    2011-01-01

    Background Algae are becoming an increasingly important component of land plant metabolic engineering projects. Land plants and algae have similar enough genetics to allow relatively straightforward gene transfer and they also share enough metabolic similarities that algal enzymes often function in a plant cell environment. Understanding metabolic systems in algae can provide insights into homologous systems in land plants. As examples, algal models are currently being used by several groups to better understand starch and lipid metabolism and catabolism, fields which have relevance in land plants. Importantly, land plants and algae also have enough metabolic divergence that algal genes can often provide new metabolic traits to plants. Furthermore, many algal genomes have now been sequenced, with many more in progress, and this easy access to genome-wide information has revealed that algal genomes are often relatively simple when compared with plants. Scope One example of the importance of algal, and in particular microalgal, resources to land plant research is the metabolic engineering of long-chain polyunsaturated fatty acids into oilseed crops which typically uses microalgal genes to extend existing natural plant biosynthetic pathways. This review describes both recent progress and remaining challenges in this field. PMID:22476481

  17. Amino acid-sensing ion channels in plants

    SciTech Connect

    Spalding, Edgar P.

    2014-08-12

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

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

    SciTech Connect

    Jerry D. Cohen

    2009-11-01

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

  19. Toxicity and tolerance of aluminum in plants: tailoring plants to suit to acid soils.

    PubMed

    Sade, Hemalatha; Meriga, Balaji; Surapu, Varalakshmi; Gadi, Jogeswar; Sunita, M S L; Suravajhala, Prashanth; Kavi Kishor, P B

    2016-04-01

    Aluminum (Al) stress is one of the serious limiting factors in plant productivity in acidic soils, which constitute about 50 % of the world's potentially arable lands and causes anywhere between 25 and 80 % of yield losses depending upon the species. The mechanism of Al toxicity and tolerance has been examined in plants, which is vital for crop improvement and enhanced food production in the future. Two mechanisms that facilitate Al tolerance in plants are Al exclusion from the roots and the ability to tolerate Al in the symplast or both. Although efforts have been made to unravel Al-resistant factors, many aspects remain unclear. Certain gene families such as MATE, ALMT, ASR, and ABC transporters have been implicated in some plants for resistance to Al which would enhance the opportunities for creating crop plants suitable to grow in acidic soils. Though QTLs have been identified related to Al-tolerance, no crop plant that is tolerant to Al has been evolved so far using breeding or molecular approaches. The remarkable changes that plants experience at the physiological, biochemical and molecular level under Al stress, the vast array of genes involved in Al toxicity-tolerance, the underlying signaling events and the holistic image of the molecular regulation, and the possibility of creating transgenics for Al tolerance are discussed in this review. PMID:26796895

  20. Phosphoenolpyruvate Carboxykinase in Plants Exhibiting Crassulacean Acid Metabolism 1

    PubMed Central

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

    1973-01-01

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

  1. Fatty Acid and Lipid Transport in Plant Cells.

    PubMed

    Li, Nannan; Xu, Changcheng; Li-Beisson, Yonghua; Philippar, Katrin

    2016-02-01

    Fatty acids (FAs) and lipids are essential - not only as membrane constituents but also for growth and development. In plants and algae, FAs are synthesized in plastids and to a large extent transported to the endoplasmic reticulum for modification and lipid assembly. Subsequently, lipophilic compounds are distributed within the cell, and thus are transported across most membrane systems. Membrane-intrinsic transporters and proteins for cellular FA/lipid transfer therefore represent key components for delivery and dissemination. In addition to highlighting their role in lipid homeostasis and plant performance, different transport mechanisms for land plants and green algae - in the model systems Arabidopsis thaliana, Chlamydomonas reinhardtii - are compared, thereby providing a current perspective on protein-mediated FA and lipid trafficking in photosynthetic cells. PMID:26616197

  2. Exposure of two upland plant species to acidic fogs.

    PubMed

    Ashenden, T W; Rafarel, C R; Bell, S A

    1991-01-01

    A system is described for exposing large numbers of plants to acidic fogs. The system allows low volumes of treatment solutions to be provided at particle sizes chiefly in the 5-30 microm range (equivalent to fog/cloud droplets). Plants of Poa alpina L. and Epilobium brunnescens were propagated from material collected in Snowdonia, North Wales and exposed to fog treatments at pH values of 2.5, 3.5, 4.5 and 5.6. There were 3 x 4 h exposures per week which provided a total of 6 mm deposition. Supplementary watering was with pH 4.5 simulated acid rain (24 mm per week). After 21 weeks, there was increased lowering and a greater dry weight for plants of E. brunnescens exposed to the pH 2.5 fog in comparison with other treatments. Also, the plants used assimilated material to form shoots rather than roots. A similar increase in dry weight accumulation in the pH 2.5 treatment was found in P. alpina after 63 weeks but this was not associated with changes in assimilate partitioning. PMID:15092062

  3. Protect nuclear plant fasteners from boric acid corrosion

    SciTech Connect

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

    1992-03-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. Higher Plant Cytochrome b5 Polypeptides Modulate Fatty Acid Desaturation

    PubMed Central

    Kumar, Rajesh; Tran, Lam-Son Phan; Neelakandan, Anjanasree K.; Nguyen, Henry T.

    2012-01-01

    Background Synthesis of polyunsaturated fatty acids (PUFAs) in the endoplasmic reticulum of plants typically involves the fatty acid desaturases FAD2 and FAD3, which use cytochrome b5 (Cb5) as an electron donor. Higher plants are reported to have multiple isoforms of Cb5, in contrast to a single Cb5 in mammals and yeast. Despite the wealth of information available on the roles of FAD2 and FAD3 in PUFA synthesis, information regarding the contributions of various Cb5 isoforms in desaturase-mediated reactions is limited. Results The present functional characterization of Cb5 polypeptides revealed that all Arabidopsis Cb5 isoforms are not similarly efficient in ω-6 desaturation, as evidenced by significant variation in their product outcomes in yeast-based functional assays. On the other hand, characterization of Cb5 polypeptides of soybean (Glycine max) suggested that similar ω-6 desaturation efficiencies were shared by various isoforms. With regard to ω-3 desaturation, certain Cb5 genes of both Arabidopsis and soybean were shown to facilitate the accumulation of more desaturation products than others when co-expressed with their native FAD3. Additionally, similar trends of differential desaturation product accumulation were also observed with most Cb5 genes of both soybean and Arabidopsis even if co-expressed with non-native FAD3. Conclusions The present study reports the first description of the differential nature of the Cb5 genes of higher plants in fatty acid desaturation and further suggests that ω-3/ω-6 desaturation product outcome is determined by the nature of both the Cb5 isoform and the fatty acid desaturases. PMID:22384013

  6. Establishment of an efficient and rapid method of multiple shoot regeneration and a comparative phenolics profile in in vitro and greenhouse-grown plants of Psophocarpus tetragonolobus (L.) DC.

    PubMed

    Singh, Vinayak; Chauhan, Namita Singh; Singh, Mohit; Idris, Asif; Madanala, Raju; Pande, Veena; Mohanty, Chandra Sekhar

    2014-01-01

    An in vitro method of multiple shoot induction and plant regeneration in Psophocarpus tetragonolobus (L.) DC was developed. Cotyledons, hypocotyls, epicotyls, internodal and young seedling leaves were used as explants. MS media supplemented with various concentrations of either thidiazuron (TDZ) or N6-benzylaminopurine (BAP) along with NAA or IAA combinations were used to determine their influence on multiple shoot induction. MS media supplemented with TDZ induced direct shoot regeneration when epicotyls and internodal segments were used as explants. TDZ at 3 mg L(-1) induced highest rate (89.2 ± 3.28%) of regeneration with (13.4 ± 2.04) shoots per explant. MS media supplemented with BAP in combination with NAA or IAA induced callus mediated regeneration when cotyledons and hypocotyls were used as explants. BAP (2.5 mg L(-1)) and IAA (0.2 mg L(-1)) induced highest rate (100 ± 2.66%) of regeneration with (23.2 ± 2.66) shoots per explant. Mature plants produced from regenerated shoots were transferred successfully to the greenhouse. In a comparative study, the phenolics contents of various parts of greenhouse-grown plants with that of in vitro-raised plants showed significant variations. PMID:25482808

  7. UV-C-Induced alleviation of transcriptional gene silencing through plant-plant communication: Key roles of jasmonic acid and salicylic acid pathways.

    PubMed

    Xu, Wei; Wang, Ting; Xu, Shaoxin; Li, Fanghua; Deng, Chenguang; Wu, Lijun; Wu, Yuejin; Bian, Po

    2016-08-01

    Plant stress responses at the epigenetic level are expected to allow more permanent changes of gene expression and potentially long-term adaptation. While it has been reported that plants subjected to adverse environments initiate various stress responses in their neighboring plants, little is known regarding epigenetic responses to external stresses mediated by plant-plant communication. In this study, we show that DNA repetitive elements of Arabidopsis thaliana, whose expression is inhibited epigenetically by transcriptional gene silencing (TGS) mechanism, are activated by UV-C irradiation through airborne plant-plant and plant-plant-plant communications, accompanied by DNA demethylation at CHH sites. Moreover, the TGS is alleviated by direct treatments with exogenous methyl jasmonate (MeJA) and methyl salicylate (MeSA). Further, the plant-plant and plant-plant-plant communications are blocked by mutations in the biosynthesis or signaling of jasmonic acid (JA) or salicylic acid (SA), indicating that JA and SA pathways are involved in the interplant communication for epigenetic responses. For the plant-plant-plant communication, stress cues are relayed to the last set of receiver plants by promoting the production of JA and SA signals in relaying plants, which exhibit upregulated expression of genes for JA and SA biosynthesis and enhanced emanation of MeJA and MeSA. PMID:27131397

  8. Occurrence of pipecolic acid and pipecolic acid betaine (homostachydrine) in Citrus genus plants.

    PubMed

    Servillo, Luigi; Giovane, Alfonso; Balestrieri, Maria Luisa; Ferrari, Giovanna; Cautela, Domenico; Castaldo, Domenico

    2012-01-11

    The presence of pipecolic acid and pipecolic acid betaine, also known as homostachydrine, is herein reported for the first time in Citrus genus plants. Homostachydrine was found in fruits, seeds, and leaves of orange, lemon, and bergamot (Citrus bergamia Risso et Poit). As homostachydrine was not commercially available, as a comparative source, extracts of alfalfa leaves ( Medicago sativa L.) were used, in which homostachydrine is present at high concentration. Then, the results where confirmed by comparison with an authentic standard synthesized and purified starting from pipecolic acid. The synthesized standard was characterized by a ESI-MS/MS study using a 3D ion-trap mass spectrometer. When subjected to MS/MS fragmentation in positive ion mode, homostachydrine, unlike its lower homologue proline betaine (also known as stachydrine), showed a pattern of numerous ionic fragments that allowed unambiguous identification of the compound. For the quantitation in the plant sources, high sensitivity and specificity were achieved by monitoring the transition (158 → 72), which is absent in the fragmentation patterns of other major osmolytes commonly used as markers for studies of abiotic stress. As for the metabolic origin of homostachydrine, the occurrence in citrus plants of pipecolic acid leads to the hypothesis that it could act as a homostachydrine precursor through direct methylation. PMID:22208890

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

    PubMed Central

    Bybin, Viktor Alexandrovich; Stom, Daevard Iosifovich

    2015-01-01

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

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

    PubMed

    Bybin, Viktor Alexandrovich; Stom, Daevard Iosifovich

    2014-01-01

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

  11. An efficient in vitro shoot regeneration from immature inflorescence and ex vitro rooting of Arnebia hispidissima (Lehm). DC. - A red dye (Alkannin) yielding plant.

    PubMed

    Phulwaria, Mahendra; Shekhawat, N S

    2013-07-01

    Arnebia hispidissima, which belongs to the family Boraginaceae, is an important medicinal and dye yielding plant. The alkannin, a red dye, are root-specific secondary metabolites of A. hispidissima. Shoots were regenerated from callus derived from immature inflorescence explants obtained from field grown plants. MS medium containing 4.52 μM 2, 4-D and 3.33 μM BAP was found to be most effective for the proliferation of callus, induced on medium containing 4.52 μM 2, 4-D. Maximum number (43.1 ± 0.25) with average length (5.2 ± 0.23) of shoots regenerated when callus was transferred to MS medium supplemented with 1.11 μM BAP, 1.16 μM Kin and 0.57 μM IAA. About 75.5 % of in vitro regenerated shoots were rooted on half-strength MS medium supplemented with 9.84 μM of IBA and 200 mg l(-1) of activated charcoal. In comparison to in vitro, higher percent (90.2 %) of shoots were rooted under ex vitro conditions when treated with IBA (0.98 mM) for 5 min. Plantlets rooted in vitro as well as ex vitro were acclimatized successfully under the green house conditions. Ex vitro rooted plants exhibited higher survival percentage (75 %) as compared to in vitro rooted plantlets (60 %). Present study may be applicable in the large-scale root-specific red dye (alkannin) production via root induction under ex vitro condition. PMID:24431511

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

    PubMed

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

    2015-08-01

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

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

    PubMed Central

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

    2015-01-01

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

  14. Susceptibility of riparian wetland plants to perfluorooctanoic acid (PFOA) accumulation.

    PubMed

    Mudumbi, J B N; Ntwampe, S K O; Muganza, M; Okonkwo, J O

    2014-01-01

    As plants have been shown to accumulate organic compounds from contaminated sediments, there is a potential for long-lasting ecological impact as a result of contaminant accumulation in riparian areas of wetlands, particularly the accumulation of non-biodegradable contaminants such as perfluorooctanoic acid (PFOA). In this study, commonly found riparian wetland plants including reeds, i.e., Xanthium strumarium, Phragmites australis, Schoenoplectus corymbosus, Ruppia maritime; Populus canescens, Polygonum salicifolium, Cyperus congestus; Persicaria amphibian, Ficus carica, Artemisia schmidtiana, Eichhornia crassipes, were studied to determine their susceptibility to PFOA accumulation from PFOA contaminated riparian sediment with a known PFOA concentration, using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The bioconcentration factor (BCF) indicated that the plants affinity to PFOA accumulation was; E. crassipes, > P. sali-cifolium, > C. congestus, > P. x canescens, > P. amphibian, > F. carica, > A. schmidtiana, > X. strumarium,> P. australis, > R. maritime, > S. corymbosus. The concentration of PFOA in the plants and/or reeds was in the range 11.7 to 38 ng/g, with a BCF range of 0.05 to 0.37. The highest BCF was observed in sediment for which its core water had a high salinity, total organic carbon and a pH which was near neutral. As the studied plants had a higher affinity for PFOA, the resultant effect is that riparian plants such as E. crassipes, X. strumarium, and P. salicifolium, typified by a fibrous rooting system, which grow closer to the water edge, exacerbate the accumulation of PFOA in riparian wetlands. PMID:24933893

  15. Abscisic Acid and Abiotic Stress Tolerance in Crop Plants

    PubMed Central

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

    2016-01-01

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

  16. Influence of Removal of a Non-native Tree Species Mimosa caesalpiniifolia Benth. on the Regenerating Plant Communities in a Tropical Semideciduous Forest Under Restoration in Brazil.

    PubMed

    Podadera, Diego S; Engel, Vera L; Parrotta, John A; Machado, Deivid L; Sato, Luciane M; Durigan, Giselda

    2015-11-01

    Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species (Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified "taungya" agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in São Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ≥0.2 m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1 year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings. PMID:26105971

  17. Influence of Removal of a Non-native Tree Species Mimosa caesalpiniifolia Benth. on the Regenerating Plant Communities in a Tropical Semideciduous Forest Under Restoration in Brazil

    NASA Astrophysics Data System (ADS)

    Podadera, Diego S.; Engel, Vera L.; Parrotta, John A.; Machado, Deivid L.; Sato, Luciane M.; Durigan, Giselda

    2015-11-01

    Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species ( Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified "taungya" agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in São Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ≥0.2 m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1 year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings.

  18. Electrolytic regeneration of acid cupric chloride printed circuit board etchant. Quarterly report No. 4, April 30, 1996--July 30, 1996

    SciTech Connect

    Oxley, J.E.; Smialek, R.J.

    1996-08-30

    Tests on T&G Corp. proton selective membranes showed significant ion migration, so no membrane is yet on hand that will allow demonstration of oxygen ingress compensation with the pre-prototype scale regenerator. T&G is remaking a 14118 membrane, the membrane type that was used in successful bench scale testing several years ago. Modifications for pressurized operation of the pre-prototype scale plating cell were successful; the unit can withstand 8 psig pressure without leaking.

  19. Novel ebullated bed catalyst regeneration technology improves regenerated catalyst quality

    SciTech Connect

    Neuman, D.J.

    1995-09-01

    Regeneration of spent hydroprocessing catalysts has long been practiced by the refining industry. With increased pressures on refiners to reduce catalyst expenditures and waste generation, refiners are more frequently reusing spent hydroprocessing catalysts after ex-situ regeneration to restore catalytic activity. By reusing regenerated catalyst for at least two cycles, the refiner reduces catalyst waste by at least one-half. As environmental laws become more restrictive, spent hydroprocessing catalyst is more likely to be classified as hazardous waste. Disposal of spent catalyst, which was previously accomplished by landfilling, now requires more expensive reclamation techniques. TRICAT has introduced the TRICAT Regeneration Process (TRP), a novel ebullated bed regeneration plant, to improve the catalyst regeneration process. The ebullated bed design allows for better control of heat release during the regeneration process. As a result, the regeneration can be accomplished in a single-pass, with improved catalyst activity retention. Catalyst losses are also minimized due to reduced catalyst handling. Commercial results from the TRP have demonstrated successful scale-up of the technology from pilot scale. The plant has achieved complete recovery of the available catalyst activity with little or no losses in catalyst yield or extrudate length. The flexibility of the TRP to process a variety of catalysts is also discussed.

  20. 40 CFR 421.90 - Applicability: Description of the metallurgical acid plants subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  1. 40 CFR 421.90 - Applicability: Description of the metallurgical acid plants subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  2. 40 CFR 421.90 - Applicability: Description of the metallurgical acid plants subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  3. 40 CFR 421.90 - Applicability: Description of the metallurgical acid plants subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  4. Regeneration of carboxylic acid-laden basic sorbents by leaching with a volatile base in an organic solvent

    DOEpatents

    King, C. Judson; Husson, Scott M.

    1999-01-01

    Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with an organic solution of alkylamine thus forming an alkylamine/carboxylic acid complex which is decomposed with improved efficiency to the desired carboxylic acid and the alkylamine. Carbon dioxide addition can be used to improve the adsorption or the carboxylic acids by the solid phase sorbent.

  5. Nitric oxide and salicylic acid signaling in plant defense

    PubMed Central

    Klessig, Daniel F.; Durner, Jörg; Noad, Robert; Navarre, Duroy A.; Wendehenne, David; Kumar, Dhirendra; Zhou, Jun Ma; Shah, Jyoti; Zhang, Shuqun; Kachroo, Pradeep; Trifa, Youssef; Pontier, Dominique; Lam, Eric; Silva, Herman

    2000-01-01

    Salicylic acid (SA) plays a critical signaling role in the activation of plant defense responses after pathogen attack. We have identified several potential components of the SA signaling pathway, including (i) the H2O2-scavenging enzymes catalase and ascorbate peroxidase, (ii) a high affinity SA-binding protein (SABP2), (iii) a SA-inducible protein kinase (SIPK), (iv) NPR1, an ankyrin repeat-containing protein that exhibits limited homology to IκBα and is required for SA signaling, and (v) members of the TGA/OBF family of bZIP transcription factors. These bZIP factors physically interact with NPR1 and bind the SA-responsive element in promoters of several defense genes, such as the pathogenesis-related 1 gene (PR-1). Recent studies have demonstrated that nitric oxide (NO) is another signal that activates defense responses after pathogen attack. NO has been shown to play a critical role in the activation of innate immune and inflammatory responses in animals. Increases in NO synthase (NOS)-like activity occurred in resistant but not susceptible tobacco after infection with tobacco mosaic virus. Here we demonstrate that this increase in activity participates in PR-1 gene induction. Two signaling molecules, cGMP and cyclic ADP ribose (cADPR), which function downstream of NO in animals, also appear to mediate plant defense gene activation (e.g., PR-1). Additionally, NO may activate PR-1 expression via an NO-dependent, cADPR-independent pathway. Several targets of NO in animals, including guanylate cyclase, aconitase, and mitogen-activated protein kinases (e.g., SIPK), are also modulated by NO in plants. Thus, at least portions of NO signaling pathways appear to be shared between plants and animals. PMID:10922045

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

    SciTech Connect

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

    1993-04-01

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

  7. Somatic Embryogenesis and Plant Regeneration in Sapindus mukorossi Gaertn. from Leaf-Derived Callus Induced with 6-Benzylaminopurine.

    PubMed

    Singh, Reetika; Rai, Manoj Kumar; Kumari, Nishi

    2015-09-01

    A somatic embryogenesis system was developed for Sapindus mukorossi Gaertn. from leaf explants obtained from fresh flushes of a mature tree. Callus was induced from the midrib region of leaf explants on Murashige and Skoog (MS) medium containing different concentrations of 2,4-dichlorophenoxyacetic acid or 6-benzylaminopurine. Callus induction and somatic embryogenesis was significantly influenced by the size, physiological age, and orientation of leaf explants on the culture medium and plant growth regulators. Adaxial-side-up orientation of leaf explants significantly promoted embryogenesis in comparison with abaxial-side-up orientation. Maximum number of somatic embryos was induced on MS medium supplemented with 8.88 μM 6-benzylaminopurine. Scanning electron microscopy of embryogenic callus revealed somatic embryo origin and the development of globular-, heart-, and cotyledonary-stage somatic embryos. The frequency of maturation as well as germination of somatic embryos was higher on MS medium containing 8.88 μM 6-benzylaminopurine than on medium without 6-benzylaminopurine. Plantlets which developed from somatic embryos were acclimatized successfully with 90 % survival. PMID:26208689

  8. Controlled-release of tetracycline and lovastatin by poly(d,l-lactide-co-glycolide acid)-chitosan nanoparticles enhances periodontal regeneration in dogs

    PubMed Central

    Lee, Bor-Shiunn; Lee, Chien-Chen; Wang, Yi-Ping; Chen, Hsiao-Jan; Lai, Chern-Hsiung; Hsieh, Wan-Ling; Chen, Yi-Wen

    2016-01-01

    Chronic periodontitis is characterized by inflammation of periodontal tissues, leading to bone resorption and tooth loss. The goal of treatment is to regenerate periodontal tissues including bone and cementum lost as a consequence of disease. The local delivery of tetracycline was proven to be effective in controlling localized periodontal infection without apparent side effects. Previous studies suggested that lovastatin has a significant role in new bone formation; however, the local delivery of lovastatin might enhance its therapeutic effects. A number of local delivery devices have been developed recently, including poly(d,l-lactide-co-glycolide acid) (PLGA) nanoparticles. The aim of this study was to develop a local delivery device, PLGA-lovastatin-chitosan-tetracycline nanoparticles, which allows the sequential release of tetracycline and lovastatin to effectively control local infection and promote bone regeneration in periodontitis. The size and microstructure of nanoparticles were examined by transmission electron microscopy, Nanoparticle Size Analyzer, and Fourier transform infrared spectroscopy. The release of tetracycline and lovastatin was quantified using a UV-Vis spectrophotometer. Furthermore, the cytotoxic effect and alkaline phosphatase activity of the nanoparticles in osteoblast cell cultures as well as antibacterial activity against periodontal pathogens were investigated. Finally, the bone regeneration potential of PLGA nanoparticles in three-walled defects in beagle dogs was investigated. The results indicated that PLGA-lovastatin-chitosan-tetracycline nanoparticles showed good biocompatibility, antibacterial activity, and increased alkaline phosphatase activity. The volumetric analysis from micro-CT revealed significantly increased new bone formation in defects filled with nanoparticles in dogs. This novel local delivery device might be useful as an adjunctive treatment in periodontal regenerative therapy. PMID:26848264

  9. Controlled-release of tetracycline and lovastatin by poly(D,L-lactide-co-glycolide acid)-chitosan nanoparticles enhances periodontal regeneration in dogs.

    PubMed

    Lee, Bor-Shiunn; Lee, Chien-Chen; Wang, Yi-Ping; Chen, Hsiao-Jan; Lai, Chern-Hsiung; Hsieh, Wan-Ling; Chen, Yi-Wen

    2016-01-01

    Chronic periodontitis is characterized by inflammation of periodontal tissues, leading to bone resorption and tooth loss. The goal of treatment is to regenerate periodontal tissues including bone and cementum lost as a consequence of disease. The local delivery of tetracycline was proven to be effective in controlling localized periodontal infection without apparent side effects. Previous studies suggested that lovastatin has a significant role in new bone formation; however, the local delivery of lovastatin might enhance its therapeutic effects. A number of local delivery devices have been developed recently, including poly(D,L-lactide-co-glycolide acid) (PLGA) nanoparticles. The aim of this study was to develop a local delivery device, PLGA-lovastatin-chitosan-tetracycline nanoparticles, which allows the sequential release of tetracycline and lovastatin to effectively control local infection and promote bone regeneration in periodontitis. The size and microstructure of nanoparticles were examined by transmission electron microscopy, Nanoparticle Size Analyzer, and Fourier transform infrared spectroscopy. The release of tetracycline and lovastatin was quantified using a UV-Vis spectrophotometer. Furthermore, the cytotoxic effect and alkaline phosphatase activity of the nanoparticles in osteoblast cell cultures as well as antibacterial activity against periodontal pathogens were investigated. Finally, the bone regeneration potential of PLGA nanoparticles in three-walled defects in beagle dogs was investigated. The results indicated that PLGA-lovastatin-chitosan-tetracycline nanoparticles showed good biocompatibility, antibacterial activity, and increased alkaline phosphatase activity. The volumetric analysis from micro-CT revealed significantly increased new bone formation in defects filled with nanoparticles in dogs. This novel local delivery device might be useful as an adjunctive treatment in periodontal regenerative therapy. PMID:26848264

  10. Factors influencing in vitro shoot regeneration from leaf segments of Chrysanthemum.

    PubMed

    Naing, Aung Htay; Jeon, Su Min; Han, Jeung-Sul; Lim, Sun Hyung; Lim, Ki Byung; Kim, Chang Kil

    2014-06-01

    The objective of this research was to develop an efficient protocol for shoot regeneration from leaf segments of the Chrysanthemum cv. Vivid Scarlet by examining the effects of plant growth regulators, dark incubation period, gelling agents, and silver nitrate. The highest number of shoots per explant (12.3) was regenerated from leaf explants cultured on Murashige and Skoog (MS) medium supplemented with a combination of 1 mgL(-1) of 6-benzyladenine (BA) and 2 mgL(-1) of α-naphthaleneacetic acid (NAA) under light conditions without any initial dark period. Gelrite was the most effective gelling agent for shoot regeneration among those tested, whereas the presence of silver nitrate distinctly inhibited shoot regeneration. Superior plant growth and rooting was observed on a hormone-free MS medium solidified with Gelrite. Flow cytometry analysis revealed no ploidy variation between the regenerated plants and the mother plant grown under greenhouse conditions. The established protocol was applicable to shoot regeneration for four out of six cultivars tested. This research will facilitate the genetic transformation and micropropagation of Chrysanthemum cultivars. PMID:24961558

  11. Use of Drawing Lithography-Fabricated Polyglycolic Acid Microneedles for Transdermal Delivery of Itraconazole to a Human Basal Cell Carcinoma Model Regenerated on Mice

    NASA Astrophysics Data System (ADS)

    Zhang, Jennifer; Wang, Yan; Jin, Jane Y.; Degan, Simone; Hall, Russell P.; Boehm, Ryan D.; Jaipan, Panupong; Narayan, Roger J.

    2016-04-01

    Itraconazole is a triazole agent that is routinely used for treatment of nail infections and other fungal infections. Recent studies indicate that itraconazole can also inhibit the growth of basal cell carcinoma (BCC) through suppression of the Sonic Hedgehog (SHH) signaling pathway. In this study, polyglycolic acid microneedle arrays and stainless steel microneedle arrays were used for transdermal delivery of itraconazole to a human BCC model which was regenerated on mice. One-by-four arrays of 642- μm-long polyglycolic acid microneedles with sharp tips were prepared using injection molding and drawing lithography. Arrays of 85 stainless steel 800- μm-tall microneedles attached to syringes were obtained for comparison purposes. Skin grafts containing devitalized split-thickness human dermis that had been seeded with human keratinocytes transduced to express human SHH protein were sutured to the skin of immunodeficient mice. Mice with this human BCC model were treated daily for 2 weeks with itraconazole dissolved in 60% dimethylsulfoxane and 40% polyethylene glycol-400 solution; transdermal administration of the itraconazole solution was facilitated by either four 1 × 4 polyglycolic acid microneedle arrays or stainless steel microneedle arrays. The epidermal tissues treated with polyglycolic acid microneedles or stainless steel microneedles were markedly thinner than that of the control (untreated) graft tissue. These preliminary results indicate that microneedles may be used to facilitate transdermal delivery of itraconazole for localized treatment of BCC.

  12. Effects of rhBMP-2 on Sandblasted and Acid Etched Titanium Implant Surfaces on Bone Regeneration and Osseointegration: Spilt-Mouth Designed Pilot Study.

    PubMed

    Kim, Nam-Ho; Lee, So-Hyoun; Ryu, Jae-Jun; Choi, Kyung-Hee; Huh, Jung-Bo

    2015-01-01

    This study was conducted to evaluate effects of rhBMP-2 applied at different concentrations to sandblasted and acid etched (SLA) implants on osseointegration and bone regeneration in a bone defect of beagle dogs as pilot study using split-mouth design. Methods. For experimental groups, SLA implants were coated with different concentrations of rhBMP-2 (0.1, 0.5, and 1 mg/mL). After assessment of surface characteristics and rhBMP-2 releasing profile, the experimental groups and untreated control groups (n = 6 in each group, two animals in each group) were placed in split-mouth designed animal models with buccal open defect. At 8 weeks after implant placement, implant stability quotients (ISQ) values were recorded and vertical bone height (VBH, mm), bone-to-implant contact ratio (BIC, %), and bone volume (BV, %) in the upper 3 mm defect areas were measured. Results. The ISQ values were highest in the 1.0 group. Mean values of VBH (mm), BIC (%), and BV (%) were greater in the 0.5 mg/mL and 1.0 mg/mL groups than those in 0.1 and control groups in buccal defect areas. Conclusion. In the open defect area surrounding the SLA implant, coating with 0.5 and 1.0 mg/mL concentrations of rhBMP-2 was more effective, compared with untreated group, in promoting bone regeneration and osseointegration. PMID:26504807

  13. Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage.

    PubMed

    Mulopo, J; Zvimba, J N; Swanepoel, H; Bologo, L T; Maree, J

    2012-01-01

    Batch regeneration of barium carbonate (BaCO(3)) from barium sulphide (BaS) slurries by passing CO(2) gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO(3) recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO(2) flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO(3) were investigated. It was observed that the carbonation reaction rate for BaCO(3) regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO(2)) flow rate whereas the BaS slurry content within the range 5-10% slurry content did not significantly affect the carbonation rate. The CO(2) flow rate also had an impact on the BaCO(3) morphology. The BaCO(3) recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO(3). PMID:22233912

  14. Heparin-binding growth factor type 1 (acidic fibroblast growth factor): a potential biphasic autocrine and paracrine regulator of hepatocyte regeneration.

    PubMed Central

    Kan, M; Huang, J S; Mansson, P E; Yasumitsu, H; Carr, B; McKeehan, W L

    1989-01-01

    Heparin-binding growth factor type 1 (HBGF-1; sometimes termed acidic fibroblast growth factor) is potentially an important factor in liver regeneration. HBGF-1 alone (half-maximal effect at 60 pM) stimulated hepatocyte DNA synthesis and bound to a high-affinity receptor (Kd = 62 pM; 5000 per cell). Epidermal growth factor (EGF) neutralized or masked the mitogenic effect of HBGF-1 concurrent with appearance of low-affinity HBGF-1 binding sites. HBGF-1 reduced the inhibitory effect of transforming growth factor type beta (TGF-beta) on the EGF stimulus. Nanomolar levels of HBGF-1 decreased the EGF stimulus. An increase in hepatic HBGF-1 gene expression after partial hepatectomy precedes increases in expression of the EGF homolog, TGF-alpha, and nonparenchymal-cell-derived TGF-beta in the regenerating liver. Expression of HBGF-1 mRNA occurs in both hepatocytes and nonparenchymal cells and persists for 7 days in liver tissue after partial hepatectomy. HBGF-1 acting through a high-affinity receptor is a candidate for the early autocrine stimulus that drives hepatocyte DNA synthesis prior to or concurrent with the EGF/TGF-alpha stimulus. It may allow hepatocyte proliferation to proceed in the presence of low levels of TGF-beta. An EGF/TGF-alpha-dependent change in HBGF-1 receptor phenotype and increasing levels of nonparenchymal-cell-derived HBGF-1 and TGF-beta may serve to limit hepatocyte proliferation. Images PMID:2477840

  15. In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

    PubMed Central

    Wodewotzky, T.I.; Lima-Neto, J.F.; Pereira-Júnior, O.C.M.; Sudano, M.J.; Lima, S.A.F.; Bersano, P.R.O.; Yoshioka, S.A.; Landim-Alvarenga, F.C.

    2012-01-01

    Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium. PMID:22983182

  16. Poly(l-Lactic Acid)/Gelatin Fibrous Scaffold Loaded with Simvastatin/Beta-Cyclodextrin-Modified Hydroxyapatite Inclusion Complex for Bone Tissue Regeneration.

    PubMed

    Lee, Jung Bok; Kim, Ji Eun; Balikov, Daniel A; Bae, Min Soo; Heo, Dong Nyoung; Lee, Donghyun; Rim, Hyun Joon; Lee, Deok-Won; Sung, Hak-Joon; Kwon, Il Keun

    2016-07-01

    Recently, the application of nanostructured materials in the field of tissue engineering has garnered attention to mediate treatment and regeneration of bone defects. In this study, poly(l-lactic acid) (PLLA)/gelatin (PG) fibrous scaffolds are fabricated and β-cyclodextrin (βCD) grafted nano-hydroxyapatite (HAp) is coated onto the fibrous scaffold surface via an interaction between βCD and adamantane. Simvastatin (SIM), which is known to promote osteoblast viability and differentiation, is loaded into the remaining βCD. The specimen morphologies are characterized by scanning electron microscopy. The release profile of SIM from the drug loaded scaffold is also evaluated. In vitro proliferation and osteogenic differentiation of human adipose derived stem cells on SIM/HAp coated PG composite scaffolds is characterized by alkaline phosphatase (ALP) activity, mineralization (Alizarin Red S staining), and real time Polymerase chain reaction (PCR). The scaffolds are then implanted into rabbit calvarial defects and analyzed by microcomputed tomography for bone formation after four and eight weeks. These results demonstrate that SIM loaded PLLA/gelatin/HAp-(βCD) scaffolds promote significantly higher ALP activity, mineralization, osteogenic gene expression, and bone regeneration than control scaffolds. This suggests the potential application of this material toward bone tissue engineering. PMID:26996294

  17. Effect of preparation route on the degradation behavior and ion releasability of siloxane-poly(lactic acid)-vaterite hybrid nonwoven fabrics for guided bone regeneration.

    PubMed

    Wakita, Takashi; Nakamura, Jin; Ota, Yoshio; Obata, Akiko; Kasuga, Toshihiro; Ban, Seiji

    2011-01-01

    Two types of nonwoven fabric, consisting of siloxane-doped vaterite (SiV) and poly(lactic acid) (PLA), for guided bone regeneration (GBR) were prepared by an electrospinning. One of the fabrics, SiV-PLA(M), was derived from PLA mixed with the solution of SiV dispersed in chloroform. Another one, SiV-PLA(K), was derived from a composite prepared by kneading SiV and PLA while heating at 200°C. The SiV-PLA(K) fabric shows higher degradability in dilute NaOH aq. than the SiV-PLA(M) fabric. To improve the cellular compatibility of the fabric, the fibers were coated with hydroxyapatite (HA) by soaking in simulated body fluid. The HA-coated SiV-PLA(K) fabric showed the release of silicate ions; the amount was reduced by 1/5 to 1/8 compared with that of the HA-coated SiV-PLA(M) fabric, and the excessive release was controlled. The preparation route of kneading at 200°C led to formation of a fabric with degradation behavior and ion releasability effective for bone regeneration. PMID:21415554

  18. Effects of rhBMP-2 on Sandblasted and Acid Etched Titanium Implant Surfaces on Bone Regeneration and Osseointegration: Spilt-Mouth Designed Pilot Study

    PubMed Central

    Kim, Nam-Ho; Lee, So-Hyoun; Ryu, Jae-Jun; Choi, Kyung-Hee; Huh, Jung-Bo

    2015-01-01

    This study was conducted to evaluate effects of rhBMP-2 applied at different concentrations to sandblasted and acid etched (SLA) implants on osseointegration and bone regeneration in a bone defect of beagle dogs as pilot study using split-mouth design. Methods. For experimental groups, SLA implants were coated with different concentrations of rhBMP-2 (0.1, 0.5, and 1 mg/mL). After assessment of surface characteristics and rhBMP-2 releasing profile, the experimental groups and untreated control groups (n = 6 in each group, two animals in each group) were placed in split-mouth designed animal models with buccal open defect. At 8 weeks after implant placement, implant stability quotients (ISQ) values were recorded and vertical bone height (VBH, mm), bone-to-implant contact ratio (BIC, %), and bone volume (BV, %) in the upper 3 mm defect areas were measured. Results. The ISQ values were highest in the 1.0 group. Mean values of VBH (mm), BIC (%), and BV (%) were greater in the 0.5 mg/mL and 1.0 mg/mL groups than those in 0.1 and control groups in buccal defect areas. Conclusion. In the open defect area surrounding the SLA implant, coating with 0.5 and 1.0 mg/mL concentrations of rhBMP-2 was more effective, compared with untreated group, in promoting bone regeneration and osseointegration. PMID:26504807

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

    ERIC Educational Resources Information Center

    Friend, Douglas J. C.

    1990-01-01

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

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

    ERIC Educational Resources Information Center

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

    1976-01-01

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

  1. Carbon isotope ratios in crassulacean Acid metabolism plants: seasonal patterns from plants in natural stands.

    PubMed

    Szarek, S R

    1976-09-01

    A year round study of photosynthesis and carbon isotope fractionation was conducted with plants of Opuntia phaeacantha Engelm. and Yucca baccata Torr. occurring in natural stands at elevations of 525, 970, 1450 and 1900 m. Plant water potentials and the daytime pattern of (14)CO(2) photosynthesis were similar for all cacti along the elevational gradient, despite significant differences in temperature regime and soil water status. Carbon isotope ratios of total tissue and soluble extract fractions were relatively constant throughtout the entire year. Additionally, the sigma(13)C values were similar in all plants of the same species along the elevational gradient, i.e. -12.5 +/- 0.86 per thousand for O. phaeacantha and -15.7 +/- 0.95 per thousand for Y. baccata. The results of this study indicate Crassulacean acid metabolism predominates as the major carbon pathway of these plants, which do not facultatively utilize the reductive pentose phosphate cycle of photosynthesis as the primary carboxylation reaction. PMID:16659680

  2. WHOSE GENES ARE WE SEQUENCING? EVIDENCE FOR THE PRESENCE OF MULTIPLE GENOMES IN NATIVE AND REGENERATED HIGH PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant genome analysis has been traditionally based on an assumption that healthy plants are axenic organisms. With improved techniques for detecting microbial endophytes, evidence supporting the presence of microbial consortia associated with all major plant tissues is mounting. Herein, the isolat...

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

    SciTech Connect

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

    1991-01-01

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

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

    SciTech Connect

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

    1991-12-31

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

  5. Improved growth, productivity and quality of tomato (Solanum lycopersicum L.) plants through application of shikimic acid

    PubMed Central

    Al-Amri, Salem M.

    2013-01-01

    A field experiment was conducted to investigate the effect of seed presoaking of shikimic acid (30, 60 and 120 ppm) on growth parameters, fruit productivity and quality, transpiration rate, photosynthetic pigments and some mineral nutrition contents of tomato plants. Shikimic acid at all concentrations significantly increased fresh and dry weights, fruit number, average fresh and dry fruit yield, vitamin C, lycopene, carotenoid contents, total acidity and fruit total soluble sugars of tomato plants when compared to control plants. Seed pretreatment with shikimic acid at various doses induces a significant increase in total leaf conductivity, transpiration rate and photosynthetic pigments (Chl. a, chl. b and carotenoids) of tomato plants. Furthermore, shikimic acid at various doses applied significantly increased the concentration of nitrogen, phosphorus and potassium in tomato leaves as compared to control non-treated tomato plants. Among all doses of shikimic acid treatment, it was found that 60 ppm treatment caused a marked increase in growth, fruit productivity and quality and most studied parameters of tomato plants when compared to other treatments. On the other hand, no significant differences were observed in total photosynthetic pigments, concentrations of nitrogen and potassium in leaves of tomato plants treated with 30 ppm of shikimic acid and control plants. According to these results, it could be suggested that shikimic acid used for seed soaking could be used for increasing growth, fruit productivity and quality of tomato plants growing under field conditions. PMID:24235870

  6. Plantlet Regeneration of Tartary Buckwheat (Fagopyrum tataricum Gaertn.) in Vitro Tissue Cultures.

    PubMed

    Wang, Cheng-Long; Dong, Xue-Ni; Ding, Meng-Qi; Tang, Yi-Xiong; Zhu, Xue-Mei; Wu, Yan-Min; Zhou, Mei-Liang; Shao, Ji-Rong

    2016-01-01

    Tartary buckwheat is an ancient annual dicotyledonous herb, which is widely distributed around the world, specifically in the high altitude area of southwestern China and in the hill region of Himalayan. The plantlet regeneration of tartary buckwheat via somatic embryogenesis or multiple shoot induction was investigated in two different tartary buckwheats, Yuanzi and Xichang. The regeneration ability of Yuanzi was better than Xichang tartary buckwheat, and the hypocotyls were better than cotyledons as tartary buckwheat plantlet regeneration explants via somatic embryogenesis. The most suitable medium for callus induction was Murashige and Skoog basal medium added 2 mg/L 2, 4- dichlorophenoxyacetic acid and 1 mg/L Kinetin, which could reach up to 98.96% callus induction percentage. The plantlet regeneration percentage from callus of tartary buckwheat could reach up to 55.77%, which induced on 2.0 mg/L Benzyladenine and 1.0 mg/L KT in MS basal medium. In addition, maximum of multiple shoot induction percentage was 69.05%, which was observed in case of Yuanzi tartary buckwheat in MS basal medium with added 3.0 mg/L 6-BA and 1.0 mg/L Thidiazuron. Roots induction of regenerated plants were achieved on 1/2 MS basal medium with added 1mg/L Indole-3-Butytric acid, which has 75% survival after transferred regenerated plants to soil under field conditions. PMID:26972974

  7. Liver Regeneration

    PubMed Central

    Michalopoulos, George K.

    2009-01-01

    Liver regeneration after partial hepatectomy is a very complex and well-orchestrated phenomenon. It is carried out by the participation of all mature liver cell types. The process is associated with signaling cascades involving growth factors, cytokines, matrix remodeling, and several feedbacks of stimulation and inhibition of growth related signals. Liver manages to restore any lost mass and adjust its size to that of the organism, while at the same time providing full support for body homeostasis during the entire regenerative process. In situations when hepatocytes or biliary cells are blocked from regeneration, these cell types can function as facultative stem cells for each other. PMID:17559071

  8. Afforestation by natural regeneration or by tree planting: examples of opposite hydrological impacts evidenced by long-term field monitoring in the humid tropics

    NASA Astrophysics Data System (ADS)

    Lacombe, G.; Ribolzi, O.; de Rouw, A.; Pierret, A.; Latsachak, K.; Silvera, N.; Pham Dinh, R.; Orange, D.; Janeau, J.-L.; Soulileuth, B.; Robain, H.; Taccoen, A.; Sengphaathith, P.; Mouche, E.; Sengtaheuanghoung, O.; Tran Duc, T.; Valentin, C.

    2015-12-01

    The humid tropics are exposed to an unprecedented modernization of agriculture involving rapid and highly-mixed land-use changes with contrasted environmental impacts. Afforestation is often mentioned as an unambiguous solution for restoring ecosystem services and enhancing biodiversity. One consequence of afforestation is the alteration of streamflow variability controlling habitats, water resources and flood risks. We demonstrate that afforestation by tree planting or by natural forest regeneration can induce opposite hydrological changes. An observatory including long-term field measurements of fine-scale land-use mosaics and of hydro-meteorological variables has been operating in several headwater catchments in tropical Southeast Asia since 2001. The GR2M water balance model repeatedly calibrated over successive 1 year periods, and used in simulation mode with specific rainfall input, allowed the hydrological effect of land-use change to be isolated from that of rainfall variability in two of these catchments in Laos and Vietnam. Visual inspection of hydrographs, correlation analyses and trend detection tests allowed causality between land-use changes and changes in seasonal flows to be ascertained. In Laos, the combination of shifting cultivation system (alternation of rice and fallow) and the gradual increase of teak tree plantations replacing fallow, led to intricate flow patterns: pluri-annual flow cycles induced by the shifting system, on top of a gradual flow increase over years caused by the spread of the plantation. In Vietnam, the abandonment of continuously cropped areas mixed with patches of tree plantations led to the natural re-growth of forest communities followed by a gradual drop in streamflow. Soil infiltrability controlled by surface crusting is the predominant process explaining why two modes of afforestation (natural regeneration or planting) led to opposite changes in flow regime. Given that commercial tree plantations will continue to

  9. Comparison between two different methods of immobilizing NGF in poly(DL-lactic acid-co-glycolic acid) conduit for peripheral nerve regeneration by EDC/NHS/MES and genipin.

    PubMed

    Hsieh, Shu-Chih; Tang, Cheng-Ming; Huang, Wen-Tao; Hsieh, Ling-Ling; Lu, Chun-Mei; Chang, Chen-Jung; Hsu, Shan-hui

    2011-12-15

    For surface modification and nerve regeneration, chitosan, followed by nerve growth factor (NGF), was immobilized onto the interior surface of poly (lactic acit-co-glycolic) conduits, using EDC/NHS/MES system (EDCs) and genipin (GP). Four new conduits were, therefore, obtained and named by immobilizing order-EDCs/EDCs, GP/EDCs, EDCs/GP, and GP/GP groups. The immobilized methods used were evaluated and compared, respectively. The researchers found that the EDCs- and GP-cross-linked chitosan displayed higher hydrophilic than pure poly (DL-lactic acid-co-glycolic acid) (PLGA) in water contact angle experiment, which meant the cell compatibility was improved by the modification. Scanning electron microscopic observations revealed that the GP-cross-linking of chitosan greatly improved cell compatibility while cultured rat PC12 cells were flatter and more spindle-shaped than EDCs-cross-linked chitosan. The results concerning the GP-cross-linked chitosan revealed significant proliferation of the seeded cells relative to pure PLGA films, as determined by counting cells and MTT assay. The NGF was released from the modified conduits in two separate periods--an initial burst in 5 days and then slow release from day 10 to day 40. The GP/EDCs group had the highest NGF value among all groups after the 5th day. Finally, the controlled-release conduits were used to bridge a 10 mm rat sciatic nerve defect. Six weeks following implantation, morphological analysis revealed the highest numbers of myelinated axons in the midconduit and distal regenerated nerve in GP/EDCs group. Therefore, the results confirm that GP/EDCs groups with good cell compatibility and effective release of NGF can considerably improve peripheral nerve regeneration. PMID:21953828

  10. Cartilage Regeneration

    PubMed Central

    Tuan, Rocky S.; Chen, Antonia F.; Klatt, Brian A.

    2016-01-01

    Cartilage damaged by trauma has a limited capacity to regenerate. Current methods for treating small chondral defects include palliative treatment with arthroscopic debridement and lavage, reparative treatment with marrow stimulation techniques (e.g. microfracture), and restorative treatment, including osteochondral grafting and autologous chondrocyte implantation. Larger defects are treated by osteochondral allografting or total joint replacements. However, the future of treating cartilage defects lies in providing biologic solutions through cartilage regeneration. Laboratory and clinical studies have examined the treatment of larger lesions using tissue engineered cartilage. Regenerated cartilage can be derived from various cell types, including chondrocytes, mesenchymal stem cells, and pluripotent stem cells. Common scaffolding materials include proteins, carbohydrates, synthetic materials, and composite polymers. Scaffolds may be woven, spun into nanofibers, or configured as hydrogels. Chondrogenesis may be enhanced with the application of chondroinductive growth factors. Finally, bioreactors are being developed to enhance nutrient delivery and provide mechanical stimulation to tissue-engineered cartilage ex vivo. The multi-disciplinary approaches currently being developed to produce cartilage promise to bring the dream of cartilage regeneration in clinical use to reality. PMID:23637149

  11. EFFECT OF ACIDIC CONDITIONS ON CADMIUM UPTAKE BY THREE AQUATIC PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acidic runoff from mining and storage of mined materials creates an undesirable environmental impact on both flora and fauna. Presence of heavy metals such as Cadmium (CD) creates an additional negative factor in acidic environments. Accumulation of Cd in plant tissues of aquatic vascular plants i...

  12. 40 CFR 421.90 - Applicability: Description of the metallurgical acid plants subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability: Description of the metallurgical acid plants subcategory. 421.90 Section 421.90 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Metallurgical Acid Plants Subcategory § 421.90 Applicability: Description of the...

  13. The effect of hyaluronic acid (Cicatridine) on healing and regeneration of the uterine cervix and vagina and vulvar dystrophy therapy.

    PubMed

    Markowska, J; Madry, R; Markowska, A

    2011-01-01

    Procedures aimed at the treatment of precancerous lesions and ectopia on the uterine cervix are frequently linked to lesions of anatomical structures. The application of hyaluronic acid (Cicatridine vaginal ovules) promotes accelerated healing of the uterine cervix and acquisition of a normal shape in the uterine cervix canal. Local application of hyaluronic acid in the vagina following radiotherapy due to cancer in the uterine cervix or endometrium favourably affects the healing of post-irradiation lesions in the vagina and improves quality of life. Over 90% of patients responded positively to the application of hyaluronic acid in the form of a cream on dystrophic lesions in the vulva. Hyaluronic acid aids the healing process of post-procedural wounds in the uterine cervix, following radiotherapy applied due to cancer of the uterine cervix, endometrium and in vulvar dystrophy. PMID:21446328

  14. Energy-saving regeneration of hydrochloric acid pickling liquor: NICE3 steel project fact sheet (NICE3 2000 award winners)

    SciTech Connect

    2000-06-19

    This is a fact sheet written for the NICE3 [National Industrial Competititveness through Energy, Environment, and Economics] Program on a new process for reusing hydrochloric acid from steel pickling operations.

  15. Interactive Effects of Growth Regulators, Carbon Sources, pH on Plant Regeneration and Assessment of Genetic Fidelity Using Single Primer Amplification Reaction (SPARS) Techniques in Withania somnifera L.

    PubMed

    Fatima, Nigar; Ahmad, Naseem; Ahmad, Iqbal; Anis, Mohammad

    2015-09-01

    An improved and methodical in vitro shoot morphogenic approach through axillary bud multiplication was established in a drug yielding plant, Withania somnifera L. Effects of plant growth regulators [6-benzyladenine (BA), kinetin (Kin), 2-isopentenyladenine (2iP), and thidiazuron (TDZ)] either singly or in combination with α-napthalene acetic acid (NAA), indole-3-butyric acid (IBA), and indole-3-acetic acid (IAA) in Murashige and Skoog (MS) medium were tested. The highest regeneration frequency (90 %) with optimum number of shoots (32 ± 0.00)/explant were obtained on MS medium fortified with 2.5 μM 6-benzyladenine (BA) and 0.5 μM NAA and 30 g/l sucrose at pH 5.8. Among the tried TDZ concentrations, 0.5 μM resulted in maximum number of shoots (20.4 ± 0.40)/explant after 4 weeks of exposure. The proliferating shoot cultures established by repeated subculturing of the mother explants on the hormone-free medium produced the highest shoot number (29.4 ± 0.40) with shoot length (6.80 ± 0.12 cm)/explant at fourth subculture passage, which a decline in shoot proliferation was recorded. Different concentrations of NAA were tested for ex vitro rooting of microshoots. The maximum percentage of rooting 100 % with maximum roots (18.3 ± 0.1) was achieved in soilrite when basal portion of the microshoots were treated with 200 μM (NAA) for 15 min per shoot. The plantlets went through hardening phase in a growth chamber, prior to ex vitro transfer. The PCR-based single primer amplification reaction (SPAR) methods which include random amplified polymorphic DNA (RAPD) and direct amplification of minisatellite DNA (DAMD) markers has been used for assessment of genetic stability of micropropagated plantlets. No variation was observed in DNA fingerprinting patterns among the micropropagated and the donor plants illustrating their genetic uniformity. PMID:26152820

  16. Pretreatment by NaOH swelling and then HCl regeneration to enhance the acid hydrolysis of cellulose to glucose.

    PubMed

    Sun, Binzhe; Peng, Gege; Duan, Lian; Xu, Aihua; Li, Xiaoxia

    2015-11-01

    A simple pretreatment method, NaOH swelling at a low temperature and then HCl regeneration, was developed for depolymerization of cellulose to glucose. Cellulose was transformed into amorphous hydrogel during the treatment; and due to the easy diffusion of H(+) and Cl(-) ions into the cellulose hydrogel network as well as the strong ability of Cl(-) to disrupt the massive hydrogen bond, the hydrolysis rate was greatly enhanced. The method is effective for α-cellulose, microcrystalline cellulose, filter paper, ramie fiber and absorbent cotton. Even at a high α-cellulose concentration of 50g/L, 29.1% yield of glucose was still obtained within 10min at 160°C under microwave irradiation, where up to 16.2g/L of glucose solution was given. The influence of NaOH concentration, HCl concentration, hydrolysis temperature and time on the hydrolysis rate was investigated. The structure of cellulose hydrogel was also studied to confirm the reaction mechanism. PMID:26280097

  17. Influence of chondroitin sulfate and hyaluronic acid presence in nanofibers and its alignment on the bone marrow stromal cells: cartilage regeneration.

    PubMed

    Lee, Paul; Tran, Katelyn; Chang, Wei; Shelke, Namdev B; Kumbar, Sangamesh G; Yu, Xiaojun

    2014-08-01

    Cartilage degeneration is the major cause of disability and poses several challenges to repair and regenerate. Conventional surgical treatments often induce fibrous tissues and compromise its function. Alternative tissue engineering strategies utilized scaffolds, factors and cells alone or in combination with some degree of success. This study reports the use of nanostructured biomimetic scaffold system in regulating the rat bone marrow stem cells (rBMSCs) differentiation into chondrogenic lineage in vitro. The biometric scaffold is essentially a micro-porous polycaprolactone (PCL) spiral structure decorated with sparsely spaced bioactive PCL nanofibers. The bioactivity stems from the use of two major components of hyaline cartilage extracellular matrix (ECM) namely chondroitin sulfate (CS) and hyaluronic acid (HYA). The PCL spiral structure was surface functionalized with PCL nanofibers encapsulated with CS (20% (w/w)) and HYA (0.2% (w/w)). In order to retain and sustain the release of CS and HYA nanofibers were cross-linked using carbodiimide chemistry. This study also evaluated the effect of nanofiber alignment on rBMSCs differentiation and evaluated the production of characteristic hyaline cartilage proteins namely collagen type II and aggrecan in vitro up to 28 days. Rat bone marrow derived stem cells cultured on the aligned nanofibers expressed significantly elevated levels of collagen type II and aggrecan secretions (western blots) as compared to scaffolds decorated with random fibers and tissue culture polystyrene (TCPS). This fiber alignment dependent expression of collagen type II and aggrecan secretion were further confirmed through immunofluorescence staining. This biomimetic and bioactive scaffold may serve as a serve as an efficient scaffold system for cartilage regeneration. PMID:25016647

  18. In Vitro and in Vivo Studies of Novel Poly(D,L-lactic acid), Superhydrophilic Carbon Nanotubes, and Nanohydroxyapatite Scaffolds for Bone Regeneration.

    PubMed

    Siqueira, Idalia A W B; Corat, Marcus Alexandre F; Cavalcanti, Bruno das Neves; Ribeiro Neto, Wilson Alves; Martin, Airton Abrahao; Bretas, Rosario Elida Suman; Marciano, Fernanda Roberta; Lobo, Anderson Oliveira

    2015-05-13

    Poly(D,L-lactide acid, PDLLA) has been researched for scaffolds in bone regeneration. However, its hydrophobocity and smooth surface impedes its interaction with biological fluid and cell adhesion. To alter the surface characteristics, different surface modification techniques have been developed to facilitate biological application. The present study compared two different routes to produce PDLLA/superhydrophilic vertically aligned carbon nanotubes:nanohydroxyapatite (PDLLA/VACNT-O:nHAp) scaffolds. For this, we used electrodeposition and immersion in simulated body fluid (SBF). Characterization by goniometry, scanning electron microscopy, X-ray diffraction, and infrared spectroscopy confirmed the polymer modifications, the in vitro bioactivity, and biomineralization. Differential scanning calorimetry and thermal gravimetric analyses showed that the inclusion of VACNT-O:nHA probably acts as a nucleating agent increasing the crystallization rate in the neat PDLLA without structural alteration. Our results showed the formation of a dense nHAp layer on all scaffolds after 14 days of immersion in SBF solution; the most intense carbonated nHAp peaks observed in the PDLLA/VACNT-O:nHAp samples suggest higher calcium precipitation compared to the PDLLA control. Both cell viability and alkaline phosphatase assays showed favorable results, because no cytotoxic effects were present and all produced scaffolds were able to induce detectable mineralization. Bone defects were used to evaluate the bone regeneration; the confocal Raman and histological results confirmed high potential for bone applications. In vivo study showed that the PDLLA/VACNT-O:nHAp scaffolds mimicked the immature bone and induced bone remodeling. These findings indicate surface improvement and the applicability of this new nanobiomaterial for bone regenerative medicine. PMID:25899398

  19. Virulent Hessian fly larvae manipulate the free amino acid content of host wheat plants.

    PubMed

    Saltzmann, Kurt D; Giovanini, Marcelo P; Zheng, Cheng; Williams, Christie E

    2008-11-01

    Gall-forming insects induce host plants to form specialized structures (galls) that provide immature life stages of the insect access to host plant nutrients and protection from natural enemies. Feeding by larvae of the Hessian fly (Mayetiola destructor Say) causes susceptible host wheat plants to produce a gall-like nutritive tissue that supports larval growth and development. To determine if changes in host plant free amino acid levels are associated with virulent Biotype L Hessian fly larval feeding, we quantified free amino acid levels in crown tissues of susceptible Newton wheat plants 1, 4, and 7 days after Hessian fly egg hatch. Hessian fly-infested susceptible plants were more responsive than resistant plants or uninfested controls, showing higher concentrations of alanine, glutamic acid, glycine, phenylalanine, proline, and serine 4 days after egg hatch. This 4-day post-hatch time point corresponds to the maturation of nutritive tissue cells in susceptible plants and the onset of rapid larval growth. By 7 days after egg hatch, when virulent second instars are actively feeding on the contents of nutritive tissue cells, the aromatic amino acids phenylalanine and tyrosine were more abundant compared to uninfested controls, but the levels of other free amino acids were no longer elevated. Changes in free amino acid abundance described in this report were associated with increased levels of mRNA encoded by wheat genes involved in amino acid synthesis and transport. PMID:18841417

  20. Regenerable solid imine sorbents

    DOEpatents

    Gray, McMahan; Champagne, Kenneth J.; Fauth, Daniel; Beckman, Eric

    2013-09-10

    Two new classes of amine-based sorbents are disclosed. The first class comprises new polymer-immobilized tertiary amine sorbents; the second class new polymer-bound amine sorbents. Both classes are tailored to facilitate removal of acid anhydrides, especially carbon dioxide (CO.sub.2), from effluent gases. The amines adsorb acid anhydrides in a 1:1 molar ratio. Both classes of amine sorbents adsorb in the temperature range from about 20.degree. C. upwards to 90.degree. C. and can be regenerated by heating upwards to 100.degree. C.

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

    PubMed

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

    2016-01-01

    There is increasing recognition of the importance of niche optima in the shift of plant-plant interactions along environmental stress gradients. Here, we investigate whether deviation from niche optima would affect the outcome of plant-plant interactions along a soil acidity gradient (pH = 3.1, 4.1, 5.5 and 6.1) in a pot experiment. We used the acid-tolerant species Lespedeza formosa Koehne as the neighbouring plant and the acid-tolerant species Indigofera pseudotinctoria Mats. or acid-sensitive species Medicago sativa L. as the target plants. Biomass was used to determine the optimal pH and to calculate the relative interaction index (RII). We found that the relationships between RII and the deviation of soil pH from the target's optimal pH were linear for both target species. Both targets were increasingly promoted by the neighbour as pH values deviated from their optima; neighbours benefitted target plants by promoting soil symbiotic arbuscular mycorrhizal fungi, increasing soil organic matter or reducing soil exchangeable aluminium. Our results suggest that the shape of the curve describing the relationship between soil pH and facilitation/competition depends on the soil pH optima of the particular species. PMID:26740568

  2. In vitro regeneration and multiplication of Passiflora hybrid "Guglielmo Betto".

    PubMed

    Pipino, Luca; Braglia, Luca; Giovannini, Annalisa; Fascella, Giancarlo; Mercuri, Antonio

    2010-01-01

    With more than 450 species, Passiflora is the most important genus of the family Passifloraceae. It comprises many species grown for their edible fruits, for their high ornamental value, and further for the therapeutic properties. With their striking exotic flowers, they are of particular interest for the floriculture market. With the aim of evaluating the in vitro propagation of an Italian ornamental hybrid, axillary tendrils of Passiflora "Guglielmo Betto" M. Vecchia (P. incarnata L. x P. tucumanensis L.) were sterilized and placed in vitro. Direct shoot regeneration was achieved from young tendrils cultivated on MS medium containing, either 4.43 microM 6-benzylaminopurine (BAP) and 11.41 microM indoleacetic acid (IAA), or 49.20 microM 6-gamma-gamma-dimethylallylaminopurine (2iP) and 2.68 microM alpha-naphthalene acetic acid (NAA), respectively. In vitro shoot multiplication, rooting, and regenerated plant acclimatization protocols were established. PMID:20099099

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

    SciTech Connect

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

    2000-10-01

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

  4. Plants having modified response to ethylene

    DOEpatents

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

    1998-01-01

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

  5. Plants having modified response to ethylene

    DOEpatents

    Meyerowitz, E.M.; Chang, C.; Bleecker, A.B.

    1997-11-18

    The invention includes transformed plants having at least one cell transformed with a modified ETR nucleic acid. Such plants have a phenotype characterized by a decrease in the response of at least one transformed plant cell to ethylene as compared to a plant not containing the transformed plant cell. Tissue and/or temporal specificity for expression of the modified ETR nucleic acid is controlled by selecting appropriate expression regulation sequences to target the location and/or time of expression of the transformed nucleic acid. The plants are made by transforming at least one plant cell with an appropriate modified ETR nucleic acid, regenerating plants from one or more of the transformed plant cells and selecting at least one plant having the desired phenotype. 31 figs.

  6. Plants having modified response to ethylene

    DOEpatents

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

    1997-01-01

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

  7. Plants having modified response to ethylene

    DOEpatents

    Meyerowitz, E.M.; Chang, C.; Bleecker, A.B.

    1998-10-20

    The invention includes transformed plants having at least one cell transformed with a modified ETR nucleic acid. Such plants have a phenotype characterized by a decrease in the response of at least one transformed plant cell to ethylene as compared to a plant not containing the transformed plant cell. Tissue and/or temporal specificity for expression of the modified ETR nucleic acid is controlled by selecting appropriate expression regulation sequences to target the location and/or time of expression of the transformed nucleic acid. The plants are made by transforming at least one plant cell with an appropriate modified ETR nucleic acid, regenerating plants from one or more of the transformed plant cells and selecting at least one plant having the desired phenotype. 67 figs.

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

    PubMed

    Scalabrin, Elisa; Radaelli, Marta; Capodaglio, Gabriele

    2016-06-01

    The presence and relative concentration of phytohormones may be regarded as a good indicator of an organism's physiological state. The integration of the rolC gene from Agrobacterium rhizogenes and of the rat glucocorticoid receptor (gr) in Nicotiana langsdorffii Weinmann plants has shown to determine various physiological and metabolic effects. The analysis of wild and transgenic N. langsdorffii plants, exposed to different abiotic stresses (high temperature, water deficit, and high chromium concentrations) was conducted, in order to investigate the metabolic effects of the inserted genes in response to the applied stresses. The development of a new analytical procedure was necessary, in order to assure the simultaneous determination of analytes and to obtain an adequately low limit of quantification. For the first time, a sensitive HPLC-HRMS quantitative method for the simultaneous determination of salicylic acid, jasmonic acid and shikimic acid was developed and validated. The method was applied to 80 plant samples, permitting the evaluation of plant stress responses and highlighting some metabolic mechanisms. Salicylic, jasmonic and shikimic acids proved to be suitable for the comprehension of plant stress responses. Chemical and heat stresses showed to induce the highest changes in plant hormonal status, differently affecting plant response. The potential of each genetic modification toward the applied stresses was marked and particularly the resistance of the gr modified plants was evidenced. This work provides new information in the study of N. langsdorffii and transgenic organisms, which could be useful for the further application of these transgenes. PMID:26966898

  9. Plant uptake and soil retention of phthalic acid applied to Norfolk sandy loam

    SciTech Connect

    Dorney, J.R.; Weber, J.B.; Overcash, M.R.; Strek, H.J.

    1985-01-01

    Plant uptake and soil retention of /sup 14/C carboxyl-labeled phthalic acid were studied at application rates of 0.6, 6.0, 60.0, and 600.0 ppm (soil dry weight) to Norfolk sandy loam (Typic Paleudult, fine loamy, kaolinitic, thermic). Height and dry weight of corn (Zea mays L. Pioneer 3368A) (21 day), tall fescue (Festuca arundinacea Schreb. Kentucky 31) (45 day) immature soybean (Glycine max (L.) Merr. Altoona) (21 day) plant, mature soybean plant, and mature wheat (Triticum aestivum L. Butte) straw were not affected by phthalic acid applied to soil. In addition, soybean seed and wheat seed dry weight were unaffected. Immature wheat (40 day) height decreased at the 600 ppm rate. Plant uptake of phthalic acid ranged from 0 to 23 ppm and was significantly above background for all plants and plant materials except soybean pods. Fescue and immature plants exhibited the highest concentration of phthalic acid while mature wheat plants and wheat seeds exhibited the least. Most of the phthalic acid volatilized or was decomposed from the soil by the end of the study; an average of only 5.7% of the originally applied chemical was recovered in both soil or plants. An average of 0.02% of the originally applied phthalic acid leached out of the treated zone. Considering the low toxicity of phthalic acid and its relatively rapid disappearance from soil, it is unlikely to become a health hazard from contaminated plants. However, plant uptake of other toxic organics could potentially become a hazard on soils treated with sludge containing significant quantities of these substances.

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

    SciTech Connect

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

    1996-12-31

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

  11. In vitro regeneration of Eucalyptus camaldulensis.

    PubMed

    Girijashankar, V

    2012-01-01

    An efficient in vitro regeneration protocol enables mass multiplication, genetic modification and germplasm conservation of desired plants. In vitro plant regeneration was achieved from nodal segments of 18-months-old superior genotypes of Eucalyptus camaldulensis trees through direct organogenesis (DO) and direct somatic embryogenesis (DSE) pathways. Initial bud break (BB) stage occurred via DO while shoot multiplication phase followed both DO and DSE pathways. Interestingly, both BB and shoot multiplication stages were achieved on shoot induction and multiplication (SIM) media composed of Murashige and Skoog (MS) basal medium supplemented with 2 mg l(-1) benzyl aminopurine (BAP) and 0.1 mg l(-1) naphthalene acetic acid (NAA). Best shoot elongation response was observed on half strength MS fortified with 0.5 mg l(-1) BAP, while root induction and elongation was superior in 1/2 MS + 1 mg l(-1) Indole butyric acid (IBA). Full strength MS fortified with cytokinins (BAP) and weak auxin (NAA) in the ratio of 20:1 favored direct regeneration pathways. Further, half strength MS supported shoot and root development. The absence of intervening callus phase in this protocol can help in minimizing the chance occurrence of somaclones. When compared to other compositions tried, hardening in 100 % coco peat resulted in maximum survival (80 %) of the in vitro raised plantlets. For mass multiplication, fortnight subculturing of a single nodal explants for eight passages on SIM medium resulted in 60-148 shoot initials. Repeated subculturing in SIM medium induced the formation of direct somatic embryos which in turn improved the turnover capacity and enabled large scale clonal multiplication of elite and desirable trees of E. camaldulensis. Following this protocol, it takes a minimum time period of four-months between in vitro explant inoculation to hardening stage. In the present study, DO and DSE pathway of plant regeneration was reported occurring simultaneously in

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

    PubMed Central

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

    2015-01-01

    The exploration of plant behavior on a cellular scale in a minimal invasive manner is key to understanding plant adaptations to their environment. Plant hormones regulate multiple aspects of growth and development and mediate environmental responses to ensure a successful life cycle. To monitor the dynamics of plant hormone actions in intact tissue, we need qualitative and quantitative tools with high temporal and spatial resolution. Here, we describe a set of biological instruments (reporters) for the analysis of the distribution and signaling of various plant hormones. Furthermore, we provide examples of their utility for gaining novel insights into plant hormone action with a deeper focus on the drought hormone abscisic acid. PMID:26577078

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

    PubMed

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

    2015-12-01

    The exploration of plant behavior on a cellular scale in a minimal invasive manner is key to understanding plant adaptations to their environment. Plant hormones regulate multiple aspects of growth and development and mediate environmental responses to ensure a successful life cycle. To monitor the dynamics of plant hormone actions in intact tissue, we need qualitative and quantitative tools with high temporal and spatial resolution. Here, we describe a set of biological instruments (reporters) for the analysis of the distribution and signaling of various plant hormones. Furthermore, we provide examples of their utility for gaining novel insights into plant hormone action with a deeper focus on the drought hormone abscisic acid. PMID:26577078

  14. Selective reduction of biomass by hydriodic acid and its in situ regeneration from iodine by metal/hydrogen.

    PubMed

    Yang, Weiran; Grochowski, Matthew R; Sen, Ayusman

    2012-07-01

    HI returns: Hydroiodic acid is a highly selective reducing reagent for a wide variety of substrates. Its application is limited by the formation of iodine and the difficulty in reconverting that iodione back to HI in situ. We report the facile conversion of I(2) to HI by metal-catalyzed hydrogenation in the presence of water, and demonstrate the utility of this process in the conversion of fructose to 5-methyfurfural and glycerol to 2-iodopropane. PMID:22492614

  15. Using Genetic Markers to Directly Estimate Gene Flow and Reproductive Success Parameters in Plants on the Basis of Naturally Regenerated Seedlings

    PubMed Central

    Burczyk, J.; Adams, W. T.; Birkes, D. S.; Chybicki, I. J.

    2006-01-01

    Estimating seed and pollen gene flow in plants on the basis of samples of naturally regenerated seedlings can provide much needed information about “realized gene flow,” but seems to be one of the greatest challenges in plant population biology. Traditional parentage methods, because of their inability to discriminate between male and female parentage of seedlings, unless supported by uniparentally inherited markers, are not capable of precisely describing seed and pollen aspects of gene flow realized in seedlings. Here, we describe a maximum-likelihood method for modeling female and male parentage in a local plant population on the basis of genotypic data from naturally established seedlings and when the location and genotypes of all potential parents within the population are known. The method models female and male reproductive success of individuals as a function of factors likely to influence reproductive success (e.g., distance of seed dispersal, distance between mates, and relative fecundity–i.e., female and male selection gradients). The method is designed to account for levels of seed and pollen gene flow into the local population from unsampled adults; therefore, it is well suited to isolated, but also wide-spread natural populations, where extensive seed and pollen dispersal complicates traditional parentage analyses. Computer simulations were performed to evaluate the utility and robustness of the model and estimation procedure and to assess how the exclusion power of genetic markers (isozymes or microsatellites) affects the accuracy of the parameter estimation. In addition, the method was applied to genotypic data collected in Scots pine (isozymes) and oak (microsatellites) populations to obtain preliminary estimates of long-distance seed and pollen gene flow and the patterns of local seed and pollen dispersal in these species. PMID:16489237

  16. [Comparative study on selenium and amino acids content in leaves of planted and wild Scutellaria baicalensis].

    PubMed

    Sheng, Ji-Ping; Chen, Hai-Rong; Shen, Lin

    2009-01-01

    Scutellaria baicalensis is one of the most important Chinese herbs. It is widely used in Asian medicine to improve impaired brain function and to treat headaches, and used to treat prostate cancer. It is also known to be anti-inflammatory and antifungal, and also seems to have antiviral properties, including possible effectiveness against HIV. Scutellaria baicalensis tea and other products are in development. In the present study, the content of selenium (Se) in leaves of planted and wild Scutellaria baicalensis was determined by fluorescence photometer. The contents of 18 kinds of amino acids in the leaves of planted and wild Scutellaria baicalensis were determined with amino acids instruments. The results showed that the two kinds of leaves were rich in Se content, and the content of Se in planted Scutellaria baicalensis (0.051 microg x g(-1)) was not significantly different from that in wild one (0.051 microg x g(-1), alpha = 0.05). The amino acids, of which the total content was up to 14.62% and 10.25% separately, were rich in both planted and wild Scutellaria baicalensis. Among the 18 kinds of amino acids, aspartic acid, glutamic acid and leucine were comparatively high in leaves of planted and wild Scutellaria baicalensis. There are 8 kinds of amino acids essential to human body, which were higher in leaves of planted Scutellaria baicalensis than those of wild one. This study, for the first time, determined Se and amino acids content in Scutellaria baicalensis and concluded that the leaves of planted type have Se and amino acids content not lower or higher than that of wild type, and the planted type could be a good substitute of wild type in the development of Scutellaria baicalensis products. This study also provided useful data for explaining the multifunction of Scutellaria baicalensis and theological basis for developing its medical and edible value. PMID:19385241

  17. Hyperhydricity in in vitro eggplant regenerated plants: structural characteristics and involvement of BiP (Binding Protein).

    PubMed

    Picoli, E A.T.; Otoni, W C.; Figueira, M L.; Carolino, S M.B.; Almeida, R S.; Silva, E A.M.; Carvalho, C R.; Fontes, E P.B.

    2001-04-01

    The hyperhydricity in eggplant (Solanum melongena L.) plants was monitored by the induction of the ER-luminal resident protein BiP. Although tissue culture conditions may induce BiP synthesis, the accumulation of BiP in hyperhydric shoots was consistently higher than in non-hyperhydric shoots. The leaf and stem anatomy in non-hyperhydric and hyperhydric eggplant was investigated aiming to identify structural changes associated with this phenomenon. In non-hyperhydric organs there were smaller and more organized cells, besides a more differentiated vascular system when compared with its hyperhydric counterpart. Scanning electron microscopy of leaves showed that leaf surface and stomata differentiation were also affected in hyperhydric plants. PMID:11297782

  18. Fabrication of blended polycaprolactone/poly(lactic-co-glycolic acid)/β-tricalcium phosphate thin membrane using solid freeform fabrication technology for guided bone regeneration.

    PubMed

    Shim, Jin-Hyung; Huh, Jung-Bo; Park, Ju Young; Jeon, Young-Chan; Kang, Seong Soo; Kim, Jong Young; Rhie, Jong-Won; Cho, Dong-Woo

    2013-02-01

    This study developed a bioabsorbable-guided bone regeneration membrane made of blended polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and beta-tricalcium phosphate (β-TCP) using solid freeform fabrication (SFF) technology. The chemical and physical properties of the membrane were evaluated using field emission scanning electron microscopy, energy dispersive spectroscopy, and a tensile test. In vitro cell activity assays revealed that the adhesion, proliferation, and osteogenic differentiation of seeded adipose-derived stem cells (ADSCs) were significantly promoted by the PCL/PLGA/β-TCP membranes compared with PCL/PLGA membranes. When the PCL/PLGA and PCL/PLGA/β-TCP membranes were implanted on rabbit calvaria bone defects without ADSCs, microcomputed tomography and histological analyses confirmed that the SFF-based PCL/PLGA/β-TCP membranes greatly increased bone formation without the need for bone substitute materials. Moreover, tight integration, which helps to prevent exposure of the membrane, between both membranes and the soft tissues was clearly observed histologically. The SFF-based PCL/PLGA and PCL/PLGA/β-TCP membranes retained their mechanical stability for up to 8 weeks without significant collapse. Furthermore, PCL/PLGA/β-TCP underwent adequate degradation without a significant immune response at 8 weeks. PMID:22934667

  19. Cellular compatibility of a gamma-irradiated modified siloxane-poly(lactic acid)-calcium carbonate hybrid membrane for guided bone regeneration.

    PubMed

    Takeuchi, Naoshi; Machigashira, Miho; Yamashita, Daisuke; Shirakata, Yoshinori; Kasuga, Toshihiro; Noguchi, Kazuyuki; Ban, Seiji

    2011-01-01

    A bi-layered silicon-releasable membrane consisting of a siloxane-poly(lactic acid) (PLA)-vaterite hybrid material (Si-PVH) microfiber mesh and a PLA microfiber mesh has been developed by an electrospinning method for guided bone regeneration (GBR) application. The bi-layered membrane was modified to a three-laminar structure by sandwiching an additional PLA microfiber mesh between the Si-PVH and PLA microfiber meshes (Si-PVH/PLA membrane). In this study, the influence of gamma irradiation, used for sterilization, on biological properties of the Si-PVH/PLA membrane was evaluated with osteoblasts and fibroblasts. After gamma irradiation, while the average molecular weight of the Si-PVH/PLA membrane decreased, the Si-PVH/PLA membrane promoted cell proliferation and differentiation (alkaline phosphatase activity and calcification) of osteoblasts, compared with the poly(lactide-co-glycolide) membrane. These results suggest that the gamma-irradiated Si-PVH/PLA membrane is biocompatible with both fibroblasts and osteoblasts, and may have an application for GBR. PMID:21946495

  20. Single glass nanopore-based regenerable sensing platforms with a non-immobilized polyglutamic acid probe for selective detection of cupric ions.

    PubMed

    Chen, Lizhen; He, Haili; Xu, Xiaolong; Jin, Yongdong

    2015-08-19

    A single glass capillary nanopore-based sensing platform for rapid and selective detection of cupric ions is demonstrated by utilizing polyglutamic acid (PGA) as a non-immobilized probe. The detection is based on the significant decrease of ionic current through nanopore and the reversal of ion current rectification responses induced by the chelated cupric ions on the probes when in the presence of cupric ions. PGA shows high selectivity for detecting cupric ions rather than other metal ions. The sensitivity of the sensing platform can be improved about 1-2 orders of magnitude by employing asymmetric salt gradients during the measurements. And the PGA-based nanopore sensing platform shows excellent regenerability for Cu(2+) sensing applications. In addition, the method is found effective and reliable for the detection of cupric ions in real samples with small volume down to 20 μL. This nanopore-based sensing platform will find promising practical applications for the detection of cupric ions. PMID:26343431

  1. Production of L-malic acid with fixation of HCO3(-) by malic enzyme-catalyzed reaction based on regeneration of coenzyme on electrode modified by layer-by-layer self-assembly method.

    PubMed

    Zheng, Haitao; Ohno, Yoko; Nakamori, Toshihiko; Suye, Shin-Ichiro

    2009-01-01

    Malic enzyme prepared and purified from Brevundimonas diminuta IFO13182 catalyzed the decarboxylation reaction of malate to pyruvate and CO2 using NAD+ as the coenzyme, and the reverse reaction was used in the present study for L-malic acid production with fixation of HCO3(-) as a model compound for carbon source. The L-malic acid production was based on electrochemical regeneration of NADH on a carbon plate electrode modified by layer-by-layer adsorption of polymer-bound mediator (Alginic acid bound viologen derivative, Alg-V), polymer-bound coenzyme (Alginic acid bound NAD+, Alg-NAD+), and lipoamide dehydrogenase (LipDH). Electrochemical reduction of immobilized NAD+ catalyzed by LipDH in a multilayer film was achieved, and the L-malic acid production with HCO3(-) fixation system with layer-by-layer immobilization of Alg-V/LipDH/Alg-NAD+/malic enzyme multilayer film on the electrode gave an L-malic acid production of nearly 11.9 mmol and an HCO3(-) fixation rate of nearly 47.4% in a buffer containing only KHCO3 and pyruvic acid potassium salt, using a cation exchange membrane. The total turnover number of NADH within 48 h was about 19,000, which suggests that efficient NADH regeneration and fast electron transfer were achieved within the multilayer film, and that the modified electrode is a potential method for the fixation of HCO3(-) without addition of free coenzyme. PMID:19147103

  2. Development of tailored and self-mineralizing citric acid-crosslinked hydrogels for in situ bone regeneration.

    PubMed

    Sánchez-Ferrero, Aitor; Mata, Álvaro; Mateos-Timoneda, Miguel A; Rodríguez-Cabello, José C; Alonso, Matilde; Planell, Josep; Engel, Elisabeth

    2015-11-01

    Bone tissue engineering demands alternatives overcoming the limitations of traditional approaches in the context of a constantly aging global population. In the present study, elastin-like recombinamers hydrogels were produced by means of carbodiimide-catalyzed crosslinking with citric acid, a molecule suggested to be essential for bone nanostructure. By systematically studying the effect of the relative abundance of reactive species on gelation and hydrogel properties such as functional groups content, degradation and structure, we were able to understand and to control the crosslinking reaction to achieve hydrogels mimicking the fibrillary nature of the extracellular matrix. By studying the effect of polymer concentration on scaffold mechanical properties, we were able to produce hydrogels with a stiffness value of 36.13 ± 10.72 kPa, previously suggested to be osteoinductive. Microstructured and mechanically-tailored hydrogels supported the growth of human mesenchymal stem cells and led to higher osteopontin expression in comparison to their non-tailored counterparts. Additionally, tailored hydrogels were able to rapidly self-mineralize in biomimetic conditions, evidencing that citric acid was successfully used both as a crosslinker and a bioactive molecule providing polymers with calcium phosphate nucleation capacity. PMID:26264645

  3. Natural toxins that affect plant amino acid metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Regenerator seal

    NASA Technical Reports Server (NTRS)

    Davis, Leonard C. (Inventor); Pacala, Theodore (Inventor); Sippel, George R. (Inventor)

    1981-01-01

    A method for manufacturing a hot side regenerator cross arm seal assembly having a thermally stablilized wear coating with a substantially flat wear surface thereon to seal between low pressure and high pressure passages to and from the hot inboard side of a rotary regenerator matrix includes the steps of forming a flat cross arm substrate member of high nickel alloy steel; fixedly securing the side edges of the substrate member to a holding fixture with a concave surface thereacross to maintain the substrate member to a slightly bent configuration on the fixture surface between the opposite ends of the substrate member to produce prestress therein; applying coating layers on the substrate member including a wear coating of plasma sprayed nickel oxide/calcium flouride material to define a wear surface of slightly concave form across the restrained substrate member between the free ends thereon; and thereafter subjecting the substrate member and the coating thereon to a heat treatment of 1600.degree. F. for sixteen hours to produce heat stabilizing growth in the coating layers on the substrate member and to produce a thermally induced growth stress in the wear surface that substantially equalizes the prestress in the substrate whereby when the cross arm is removed from the fixture surface following the heat treatment step a wear face is formed on the cross arm assembly that will be substantially flat between the ends.

  5. Effect of cross-linking reagents for hyaluronic acid hydrogel dermal fillers on tissue augmentation and regeneration.

    PubMed

    Yeom, Junseok; Bhang, Suk Ho; Kim, Byung-Soo; Seo, Moo Seok; Hwang, Eui Jin; Cho, Il Hwan; Park, Jung Kyu; Hahn, Sei Kwang

    2010-02-17

    A novel, biocompatible, and nontoxic dermal filler using hyaluronic acid (HA) hydrogels was successfully developed for tissue augmentation applications. Instead of using highly reactive cross-linkers such as divinyl sulfone (DVS) for Hylaform, 1,4-butanediol diglycidyl ether (BDDE) for Restylane, and 1,2,7,8-diepoxyoctane (DEO) for Puragen, HA hydrogels were prepared by direct amide bond formation between the carboxyl groups of HA and hexamethylenediamine (HMDA) with an optimized carboxyl group modification for effective tissue augmentation. The HA-HMDA hydrogels could be prepared within 5 min by the addition of HMDA to HA solution activated with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and 1-hydroxybenzotriazole monohydrate (HOBt). Five kinds of samples, a normal control, a negative control, a positive control of Restylane, adipic acid dihydrazide grafted HA (HA-ADH) hydrogels, and HA-HMDA hydrogels, were subcutaneously injected to wrinkled model mice. According to the image analysis on dorsal skin augmentation, the HA-HMDA hydrogels exhibited the best tissue augmentation effect being stable longer than 3 months. Furthermore, histological analyses after hematoxylin-eosin (H&E) and Masson's trichrome staining revealed the excellent biocompatibility and safety of HA-HMDA hydrogels. The dermal thickness and the dermal collagen density in wrinkled mice after treatment with HA-HMDA hydrogels for 12 weeks were comparable to those of normal mice. Compared with HA-DVS hydrogels and Restylane, the excellent tissue augmentation by HA-HMDA hydrogels might be ascribed to the biocompatible residues of amine groups in the cross-linker of HMDA. The HA-HMDA hydrogels will be investigated further as a novel dermal filler for clinical applications. PMID:20078098

  6. Determination of free and total phenolic acids in plant-derived foods by HPLC with diode-array detection.

    PubMed

    Mattila, Pirjo; Kumpulainen, Jorma

    2002-06-19

    A high-performance liquid chromatographic (HPLC) method with diode-array detection (DAD) was used to identify and quantify free and total phenolic acids (m-hydroxybenzoic acid, p-hydroxybenzoic acid, protocatechuic acid, gallic acid, vanillic acid, syringic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, ferulic acid, sinapic acid, chlorogenic acid, and ellagic acid) in plant foods. Free phenolic acids were extracted with a mixture of methanol and 10% acetic acid. Bound phenolic acids were liberated using first alkaline and then acid hydrolysis followed by extraction with diethyl ether/ethyl acetate (1:1). All fractions were quantified separately by HPLC. After HPLC quantification, results of alkali and acid hydrolysates were calculated to represent total phenolic acids. Ellagic acid was quantified separately after long (20 h) acid hydrolysis. The methods developed were effective for the determination of phenolic acids in plant foods. DAD response was linear for all phenolic acids within the ranges evaluated, with correlation coefficients exceeding 0.999. Coefficients of variation for 4-8 sample replicates were consistently below 10%. Recovery tests of phenolic acids were performed for every hydrolysis condition using several samples. Recoveries were generally good (mean >90%) with the exceptions of gallic acid and, in some cases, caffeic acid samples. PMID:12059140

  7. Down-regulation of multiple CDK inhibitor ICK/KRP genes promotes cell proliferation, callus induction and plant regeneration in Arabidopsis

    PubMed Central

    Cheng, Yan; Liu, Han; Cao, Ling; Wang, Sheng; Li, Yongpeng; Zhang, Yuanyuan; Jiang, Wei; Zhou, Yongming; Wang, Hong

    2015-01-01

    The ICK/KRP cyclin-dependent kinase (CDK) inhibitors are important plant cell cycle regulators sharing only limited similarity with the metazoan CIP/KIP family of CDK inhibitors. Information is still limited regarding the specific functions of different ICK/KRP genes in planta. We have shown previously that down-regulation of multiple CDK inhibitor ICK/KRP genes up-regulates the E2F pathway and increases cell proliferation, and organ and seed sizes in Arabidopsis. In this study, we observed that the quintuple ick1/2/5/6/7 mutant had more cells in the cortical layer of the root apical meristem (RAM) than the wild type (Wt) while its RAM length was similar to that of the Wt, suggesting a faster cell cycle rate in the quintuple mutant. We further investigated the effects of down-regulating ICK genes on tissue culture responses. The cotyledon explants of ick1/2/5/6/7 could form callus efficiently in the absence of cytokinin and also required a lower concentration of 2,4-D for callus induction compared to the Wt plants, suggesting increased competence for callus induction in the mutant. In addition, the quintuple ick mutant showed enhanced abilities to regenerate shoots and roots, suggesting that increased competence to enter the cell cycle in the quintuple mutant might make it possible for more cells to become proliferative and be utilized to form shoots or roots. These findings indicate that CDK activity is a major factor underlying callus induction and increased cell proliferation can enhance in vitro organogenesis. PMID:26528298

  8. Closed end regeneration method

    DOEpatents

    Yang, Arthur Jing-Min; Zhang, Yuehua

    2006-06-27

    A nanoporous reactive adsorbent incorporates a relatively small number of relatively larger reactant, e.g. metal, enzyme, etc. particles (10) forming a discontinuous or continuous phase interspersed among and surrounded by a continuous phase of smaller adsorbent particles (12) and connected interstitial pores (14) therebetween. The reactive adsorbent can effectively remove inorganic or organic impurities in a liquid by causing the liquid to flow through the adsorbent. For example, silver ions may be adsorbed by the adsorbent particles (12) and reduced to metallic silver by reducing metal, such as irons, as the reactant particles (10). The column can be regenerated by backwashing with the liquid effluent containing, for example, acetic acid.

  9. Floral Induction of Vegetative Plants Supplied a Purified Fraction of Deoxyribonucleic Acid from Stems of Flowering Plants 1

    PubMed Central

    Wardell, William L.

    1977-01-01

    It has been found that floral induced stems of flowering tobacco (Nicotiana tabacum cv. Wis. 38) plants contain large amounts of rapidly renaturing DNA, whereas noninduced stems of vegetative plants contain only small amounts. In addition, it has been shown that the striking qualitative difference in DNA between stems of flowering and vegetative plants mimics the over-all quantitative difference in DNA content (on a fresh weight basis). Therefore, the extra DNA in stems of flowering plants seems, at least in part, to represent preferential synthesis of rapidly renaturing DNA. Rapidly renatured DNA (flowering plants) has been purified (cesium chloride gradients) from heated-cooled DNA solution and under noninductive conditions has been tested for floral activity. It has been found that when rapidly renatured DNA in buffer solution is supplied to axillary vegetative buds of vegetative plants and then the axillary buds are defoliated every 4th day for 12 days, the treated buds change into flower buds. On the other hand, control axillary buds supplied buffer solution alone remain vegetative. In stem segments from flowering plants, the concept, discussed in previous reports, that indole-3-acetic acid may modify in vitro bud expression by directly affecting DNA synthesis has been reviewed. On the basis of this report, the concept is elaborated by proposing here that indole-3-acetic acid may act partially in bud expression by directly suppressing synthesis of rapidly renaturing DNA. PMID:16660207

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  12. The Regulation of Essential Amino Acid Synthesis and Accumulation in Plants.

    PubMed

    Galili, Gad; Amir, Rachel; Fernie, Alisdair R

    2016-04-29

    Although amino acids are critical for all forms of life, only proteogenic amino acids that humans and animals cannot synthesize de novo and therefore must acquire in their diets are classified as essential. Nine amino acids-lysine, methionine, threonine, phenylalanine, tryptophan, valine, isoleucine, leucine, and histidine-fit this definition. Despite their nutritional importance, several of these amino acids are present in limiting quantities in many of the world's major crops. In recent years, a combination of reverse genetic and biochemical approaches has been used to define the genes encoding the enzymes responsible for synthesizing, degrading, and regulating these amino acids. In this review, we describe recent advances in our understanding of the metabolism of the essential amino acids, discuss approaches for enhancing their levels in plants, and appraise efforts toward their biofortification in crop plants. PMID:26735064

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Surface disinfection procedure and in vitro regeneration of grapevine (Vitis vinifera L.) axillary buds.

    PubMed

    Lazo-Javalera, M F; Troncoso-Rojas, R; Tiznado-Hernández, M E; Martínez-Tellez, M A; Vargas-Arispuro, I; Islas-Osuna, M A; Rivera-Domínguez, M

    2016-01-01

    Establishment of an efficient explants surface disinfection protocol is essential for in vitro cell and tissue culture as well as germplasm conservation, such as the case of Grapevine (Vitis spp.) culture. In this research, different procedures for disinfection and regeneration of field-grown grapevine cv. 'Flame seedless' axillary buds were evaluated. The buds were disinfected using either NaOCl or allyl, benzyl, phenyl and 2-phenylethyl isothiocyanates. Two different media for shooting and four media for rooting were tested. Shoot and root development per buds were registered. The best disinfection procedure with 90 % of tissue survival involved shaking for 60 min in a solution containing 20 % Clorox with 50 drops/L Triton(®) X-100. These tissues showed the potential to regenerate a complete plant. Plant regeneration was conducted using full strength Murashigue and Skoog (MS) medium supplemented with 8 µM benzyl aminopurine for shoot induction and multiplication, whereas rooting was obtained on half strength MS supplemented with 2 mg L(-1) of indole-3-butyric acid and 200 mg L(-1) of activated charcoal. In this work, it was designed the protocols for obtaining sterile field-grown grapevine buds and in vitro plant development. This methodology showed potential to produce vigorous and healthy plants in 5 weeks for clonal grapevine propagation. Regenerated plants were successfully established in soil. PMID:27119057

  15. Biocompatibility assessment of novel collagen-sericin scaffolds improved with hyaluronic Acid and chondroitin sulfate for cartilage regeneration.

    PubMed

    Dinescu, Sorina; Gălăţeanu, Bianca; Albu, Mădălina; Lungu, Adriana; Radu, Eugen; Hermenean, Anca; Costache, Marieta

    2013-01-01

    Cartilage tissue engineering (CTE) applications are focused towards the use of implantable biohybrids consisting of biodegradable scaffolds combined with in vitro cultured cells. Hyaluronic acid (HA) and chondroitin sulfate (CS) were identified as the most potent prochondrogenic factors used to design new biomaterials for CTE, while human adipose-derived stem cells (ASCs) were proved to display high chondrogenic potential. In this context, our aim was not only to build novel 3D porous scaffolds based on natural compounds but also to evaluate their in vitro biological performances. Therefore, for prospective CTE, collagen-sericin (Coll-SS) scaffolds improved with HA (5% or 10%) and CS (5% or 10%) were used as temporary physical supports for ASCs and were analyzed in terms of structural, thermal, morphological, and swelling properties and cytotoxic potential. To complete biocompatibility data, ASCs viability and proliferation potential were also assessed. Our studies revealed that Coll-SS hydrogels improved with 10% HA and 5% CS displayed the best biological performances in terms of cell viability, proliferation, morphology, and distribution. Thus, further work will address a novel 3D system including both HA 10% and CS 5% glycoproteins, which will probably be exposed to prochondrogenic conditions in order to assess its potential use in CTE applications. PMID:24308001

  16. Compositional and in Vitro Evaluation of Nonwoven Type I Collagen/Poly-dl-lactic Acid Scaffolds for Bone Regeneration

    PubMed Central

    Qiao, Xiangchen; Russell, Stephen J.; Yang, Xuebin; Tronci, Giuseppe; Wood, David J.

    2015-01-01

    Poly-dl-lactic acid (PDLLA) was blended with type I collagen to attempt to overcome the instantaneous gelation of electrospun collagen scaffolds in biological environments. Scaffolds based on blends of type I collagen and PDLLA were investigated for material stability in cell culture conditions (37 °C; 5% CO2) in which post-electrospinning glutaraldehyde crosslinking was also applied. The resulting wet-stable webs were cultured with bone marrow stromal cells (HBMSC) for five weeks. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), Fourier transform infra-red spectroscopy (FTIR) and biochemical assays were used to characterise the scaffolds and the consequent cell-scaffold constructs. To investigate any electrospinning-induced denaturation of collagen, identical PDLLA/collagen and PDLLA/gelatine blends were electrospun and their potential to promote osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios of 40/60, 60/40 and 80/20 resulted in satisfactory wet stabilities in a humid environment, although chemical crosslinking was essential to ensure long term material cell culture. Scaffolds of PDLLA/collagen at a 60:40 weight ratio provided the greatest stability over a five-week culture period. The PDLLA/collagen scaffolds promoted greater cell proliferation and osteogenic differentiation compared to HMBSCs seeded on the corresponding PDLLA/gelatine scaffolds, suggesting that any electrospinning-induced collagen denaturation did not affect material biofunctionality within 5 weeks in vitro. PMID:26251924

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

    SciTech Connect

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

    1998-07-01

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

  18. Method for protecting plant life from acidic atmospheric pollutants

    SciTech Connect

    Lengyel, A.D.

    1986-10-14

    A method is described for treating a stand of coniferous trees growing by natural processes and exposed to an atmosphere containing inorganic nitric acid or nitrate compounds to improve the resistance of the trees to damage by acid rain. The method consists of foliarly applying at least one sugar selected from the group consisting of monosaccharides and disaccharides to the coniferous trees naturally growing in the stand exposed to the atmosphere.

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

    SciTech Connect

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

    1990-01-01

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

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

    SciTech Connect

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

    1986-05-01

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

  1. Heart regeneration.

    PubMed

    Breckwoldt, Kaja; Weinberger, Florian; Eschenhagen, Thomas

    2016-07-01

    Regenerating an injured heart holds great promise for millions of patients suffering from heart diseases. Since the human heart has very limited regenerative capacity, this is a challenging task. Numerous strategies aiming to improve heart function have been developed. In this review we focus on approaches intending to replace damaged heart muscle by new cardiomyocytes. Different strategies for the production of cardiomyocytes from human embryonic stem cells or human induced pluripotent stem cells, by direct reprogramming and induction of cardiomyocyte proliferation are discussed regarding their therapeutic potential and respective advantages and disadvantages. Furthermore, different methods for the transplantation of pluripotent stem cell-derived cardiomyocytes are described and their clinical perspectives are discussed. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. PMID:26597703

  2. Variation of free phenolic acids in medicinal plants belonging to the Lamiaceae family.

    PubMed

    Zgórka, G; Głowniak, K

    2001-08-01

    Ten species belonging to the family Lamiaceae and representing the most popular medicinal plants used in Polish phytotherapy were examined for the content of free phenolic acids (PhAs). Two depsides, rosmarinic and chlorogenic acids, as well as eight simple PhAs, protocatechuic, gentisic, p-hydroxybenzoic, caffeic, vanillic, syringic, p-coumaric and ferulic acids, in different qualitative and quantitative proportions depending on the plant examined were determined by the rapid, selective and accurate method combining solid-phase extraction and high-performance liquid chromatography. PMID:11451645

  3. Branched-chain-amino-acid biosynthesis in plants: molecular cloning and characterization of the gene encoding acetohydroxy acid isomeroreductase (ketol-acid reductoisomerase) from Arabidopsis thaliana (thale cress).

    PubMed Central

    Dumas, R; Curien, G; DeRose, R T; Douce, R

    1993-01-01

    Towards the goal of gaining a better understanding of the molecular mechanisms controlling branched-chain-amino-acid biosynthesis in plants, we have isolated, sequenced and characterized a gene encoding acetohydroxy acid isomero-reductase (ketol-acid reductoisomerase) from Arabidopsis thaliana (thale cress). Comparison between the acetohydroxy acid isomeroreductase cDNA and the genomic sequence has allowed us to determine the exon structure of the coding region. The isolated acetohydroxy acid isomeroreductase gene is distributed over approx. 4.5 kbp and contains nine introns (79-347 bp). The transcriptional start site was found to be 52 bp upstream of the translational initiation site. Southern-blot analysis of A. thaliana genomic DNA shows that the acetohydroxy acid isomeroreductase is encoded by a single-copy gene. Images Figure 3 Figure 5 PMID:8379936

  4. The putative Cationic Amino Acid Transporter 9 is targeted to vesicles and may be involved in plant amino acid homeostasis

    PubMed Central

    Yang, Huaiyu; Stierhof, York-Dieter; Ludewig, Uwe

    2015-01-01

    Amino acids are major primary metabolites. Their uptake, translocation, compartmentation, and re-mobilization require a diverse set of cellular transporters. Here, the broadly expressed gene product of CATIONIC AMINO ACID TRANSPORTER 9 (CAT9) was identified as mainly localized to vesicular membranes that are involved in vacuolar trafficking, including those of the trans-Golgi network. In order to probe whether and how these compartments are involved in amino acid homeostasis, a loss-of-function cat9-1 mutant and ectopic over-expressor plants were isolated. Under restricted nitrogen supply in soil, cat9-1 showed a chlorotic phenotype, which was reversed in the over-expressors. The total soluble amino acid pools were affected in the mutants, but this was only significant under poor nitrogen supply. Upon nitrogen starvation, the soluble amino acid leaf pools were lower in the over-expressor, compared with cat9-1. Over-expression generally affected total soluble amino acid concentrations, slightly delayed development, and finally improved the survival upon severe nitrogen starvation. The results potentially identify a novel function of vesicular amino acid transport mediated by CAT9 in the cellular nitrogen-dependent amino acid homeostasis. PMID:25883600

  5. The putative Cationic Amino Acid Transporter 9 is targeted to vesicles and may be involved in plant amino acid homeostasis.

    PubMed

    Yang, Huaiyu; Stierhof, York-Dieter; Ludewig, Uwe

    2015-01-01

    Amino acids are major primary metabolites. Their uptake, translocation, compartmentation, and re-mobilization require a diverse set of cellular transporters. Here, the broadly expressed gene product of CATIONIC AMINO ACID TRANSPORTER 9 (CAT9) was identified as mainly localized to vesicular membranes that are involved in vacuolar trafficking, including those of the trans-Golgi network. In order to probe whether and how these compartments are involved in amino acid homeostasis, a loss-of-function cat9-1 mutant and ectopic over-expressor plants were isolated. Under restricted nitrogen supply in soil, cat9-1 showed a chlorotic phenotype, which was reversed in the over-expressors. The total soluble amino acid pools were affected in the mutants, but this was only significant under poor nitrogen supply. Upon nitrogen starvation, the soluble amino acid leaf pools were lower in the over-expressor, compared with cat9-1. Over-expression generally affected total soluble amino acid concentrations, slightly delayed development, and finally improved the survival upon severe nitrogen starvation. The results potentially identify a novel function of vesicular amino acid transport mediated by CAT9 in the cellular nitrogen-dependent amino acid homeostasis. PMID:25883600

  6. Nematodes Associated with Plants from Naturally Acidic Wetlands Soil

    PubMed Central

    Cox, Robert John; Smart, Grover C.

    1994-01-01

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

  7. New layers in understanding and predicting α-linolenic acid content in plants using amino acid characteristics of omega-3 fatty acid desaturase.

    PubMed

    Zinati, Zahra; Zamansani, Fatemeh; Hossein KayvanJoo, Amir; Ebrahimi, Mahdi; Ebrahimi, Mansour; Ebrahimie, Esmaeil; Mohammadi Dehcheshmeh, Manijeh

    2014-11-01

    α-linolenic acid (ALA) is the most frequent omega-3 in plants. The content of ALA is highly variable, ranging from 0 to 1% in rice and corn to >50% in perilla and flax. ALA production is strongly correlated with the enzymatic activity of omega-3 fatty acid desaturase. To unravel the underlying mechanisms of omega-3 diversity, 895 protein features of omega-3 fatty acid desaturase were compared between plants with high and low omega-3. Attribute weighting showed that this enzyme in plants with high omega-3 content has higher amounts of Lys, Lys-Phe, and Pro-Asn but lower Aliphatic index, Gly-His, and Pro-Leu. The Random Forest model with Accuracy criterion when run on the dataset pre-filtered with Info Gain algorithm was the best model in distinguishing high omega-3 content based on the frequency of Lys-Lys in the structure of fatty acid desaturase. Interestingly, the discriminant function algorithm could predict the level of omega-3 only based on the six important selected attributes (out of 895 protein attributes) of fatty acid desaturase with 75% accuracy. We developed "Plant omega3 predictor" to predict the content of α-linolenic acid based on structural features of omega-3 fatty acid desaturase. The software calculates the 6 key structural protein features from imported Fasta sequence of omega-3 fatty acid desaturase or utilizes the imported features and predicts the ALA content using discriminant function formula. This work unravels an underpinning mechanism of omega-3 diversity via discovery of the key protein attributes in the structure of omega-3 desaturase offering a new approach to obtain higher omega-3 content. PMID:25199845

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

    PubMed Central

    Raffaele, Sylvain; Leger, Amandine

    2009-01-01

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

  9. Effect of the structure of gallic acid and its derivatives on their interaction with plant ferritin.

    PubMed

    Wang, Qunqun; Zhou, Kai; Ning, Yong; Zhao, Guanghua

    2016-12-15

    Gallic acid and its derivatives co-exist with protein components in foodstuffs, but there is few report on their interaction with proteins. On the other hand, plant ferritin represents not only a novel class of iron supplement, but also a new nanocarrier for encapsulation of bioactive nutrients. However, plant ferritin is easy to be degraded by pepsin in the stomach, thereby limiting its application. Herein, we investigated the interaction of gallic acid and its derivatives with recombinant soybean seed H-2 ferritin (rH-2). We found that these phenolic acids interacted with rH-2 in a structure-dependent manner; namely, gallic acid (GA), methyl gallate (MEGA) and propyl gallate (PG) having three HO groups can bind to rH-2, while their analogues with two HO groups cannot. Consequently, such binding largely inhibited ferritin degradation by pepsin. These findings advance our understanding of the relationship between the structure and function of phenolic acids. PMID:27451180

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

    PubMed

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

    2015-10-01

    Field studies were conducted in the United States, Hungary, and New Zealand to evaluate the effectiveness of septa lures loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E)-4,8-dimethyl-1,3,7-nonatriene (nonatriene) alone and in combination with an acetic acid co-lure for both sexes of codling moth, Cydia pomonella (L.). Additional studies were conducted to evaluate these host plant volatiles and acetic acid in combination with the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone). Traps baited with pear ester/nonatriene + acetic acid placed within orchards treated either with codlemone dispensers or left untreated caught significantly more males, females, and total moths than similar traps baited with pear ester + acetic acid in some assays. Similarly, traps baited with codlemone/pear ester/nonatriene + acetic acid caught significantly greater numbers of moths than traps with codlemone/pear ester + acetic acid lures in some assays in orchards treated with combinational dispensers (dispensers loaded with codlemone/pear ester). These data suggest that monitoring of codling moth can be marginally improved in orchards under variable management plans using a binary host plant volatile lure in combination with codlemone and acetic acid. These results are likely to be most significant in orchards treated with combinational dispensers. Significant increases in the catch of female codling moths in traps with the binary host plant volatile blend plus acetic acid should be useful in developing more effective mass trapping strategies. PMID:26314018

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Effect of plant growth regulators on fatty acids composition in Jatropha curcas L. callus culture.

    PubMed

    Hernandez, Ludwi Rodríguez; Mendiola, Martha A Rodríguez; Castro, Carlos Arias; Gutiérrez-Miceli, Federico A

    2015-01-01

    The influence of Naphtaleneacetic acid (NAA) and 6-Benzylaminopurine (BAP) on callus formation, its morphology and fatty acids profile were examined from Jatropha curcas L. Embryo from seeds of J. curcas L. were sown in Murashige and skoog (MS) medium with NAA and BAP. All treatments induced callus formation, however callus morphology was different in most of the treatments. Higher callus biomass was presented with 1.0 NAA + 0.5 BAP mg/L. Plant growth regulators modifies the fatty acids profile in callus of J. curcas L. BAP was induced linoleic and linolenic acids. PMID:25757437

  13. Local and Systemic Biosynthesis of Salicylic Acid in Infected Cucumber Plants.

    PubMed Central

    Meuwly, P.; Molders, W.; Buchala, A.; Metraux, J. P.

    1995-01-01

    Radiolabeling studies showed that salicylic acid (SA), an essential component in the signal transduction pathway leading to systemic acquired resistance, is synthesized from phenylalanine (Phe) and benzoic acid in cucumber (Cucumis sativus L.) plants inoculated with pathogens. Leaf discs from plants inoculated with either tobacco necrosis virus or Pseudomonas lachrymans incorporated more [14C]Phe into [14C]SA than mock-inoculated controls. The identity of SA was confirmed by gas chromatography-mass spectrometry. No reduction in specific activity of [14C]SA was observed for either free or bound SA between control and infected plants after feeding [14C]Phe. A specific inhibitor of Phe ammonia-lyase, 2-aminoindan-2-phosphonic acid, completely inhibited the incorporation of [14C]Phe into [14C]SA, although plants treated with 2-aminoindan-2-phosphonic acid could still produce [14C]SA from [14C]benzoic acid. Biosynthesis of SA in tissue inoculated with tobacco necrosis virus followed a transient pattern with the highest induction occurring 72 h postinoculation. Uninfected tissues from an infected plant synthesized de novo more SA than did controls. This suggests the involvement of a systemic signal triggering SA synthesis in tissue distant from the site of infection that display systemic acquired resistance. PMID:12228656

  14. Genetic analysis of pathway regulation for enhancing branched-chain amino acid biosynthesis in plants.

    PubMed

    Chen, Hao; Saksa, Kristen; Zhao, Feiyi; Qiu, Joyce; Xiong, Liming

    2010-08-01

    The branched-chain amino acids (BCAAs) valine, leucine and isoleucine are essential amino acids that play critical roles in animal growth and development. Animals cannot synthesize these amino acids and must obtain them from their diet. Plants are the ultimate source of these essential nutrients, and they synthesize BCAAs through a conserved pathway that is inhibited by its end products. This feedback inhibition has prevented scientists from engineering plants that accumulate high levels of BCAAs by simply over-expressing the respective biosynthetic genes. To identify components critical for this feedback regulation, we performed a genetic screen for Arabidopsis mutants that exhibit enhanced resistance to BCAAs. Multiple dominant allelic mutations in the VALINE-TOLERANT 1 (VAT1) gene were identified that conferred plant resistance to valine inhibition. Map-based cloning revealed that VAT1 encodes a regulatory subunit of acetohydroxy acid synthase (AHAS), the first committed enzyme in the BCAA biosynthesis pathway. The VAT1 gene is highly expressed in young, rapidly growing tissues. When reconstituted with the catalytic subunit in vitro, the vat1 mutant-containing AHAS holoenzyme exhibits increased resistance to valine. Importantly, transgenic plants expressing the mutated vat1 gene exhibit valine tolerance and accumulate higher levels of BCAAs. Our studies not only uncovered regulatory characteristics of plant AHAS, but also identified a method to enhance BCAA accumulation in crop plants that will significantly enhance the nutritional value of food and feed. PMID:20497381

  15. Sulfate metabolism. I. Sulfate uptake and redistribution of acid rain sulfate by edible plants

    SciTech Connect

    Dallam, R.D.

    1987-03-23

    Sulfur is the major component of polluted air in industrialized societies. Atmospheric sulfur is converted to sulfuric acid through a series of chemical reactions which can eventually reenter many ecosystems. When edible plants are grown in soils containing varying amounts of sulfate, the roots take up and transport inorganic sulfate to the stems and leaves. The sulfate taken up by the roots and the amount transported to the stem and leaves was found to be a function of the concentration of sulfate in the soil. Inorganic sulfate taken up by a corn plant seedling can be rapidly converted to organic sulfate by the root system. Nine days after one of a pair of pea plants was inoculated with artificial acid rain sulfate (dilute H/sub 2//sup 35/SO/sub 4/) it was found that the sulfate was translocated not only in the inoculated plant, but also to the uninoculated pea plant in the same container. Also, when the leaves of a mature potato plant were inoculated with artificial acid rain sulfate it was found that the sulfate was translocated into the edible potatoes. Fractionation of the potatoes showed that most of the sulfate was water soluble of which 30% was inorganic sulfate and 70% was in the form of organic sulfur. One third of the non-water soluble translocated acid rain sulfate was equally divided between lipid and non-lipid organic sulfur of the potato. 9 references, 2 figures, 5 tables.

  16. Changes in fatty acid composition in plant tissues expressing a mammalian delta9 desaturase.

    PubMed

    Moon, H; Hazebroek, J; Hildebrand, D F

    2000-05-01

    Plant tissues expressing a mammalian stearoyl-CoA delta9 desaturase were reported to accumulate delta9 hexadecenoic acid (16:1), normally very minor in most plant tissues. The transgenic plants were thoroughly analyzed for alterations of individual lipids in different subcellular sites. Western blot analysis indicated that the animal desaturase was targeted to the microsomes. The delta9 16:1 was incorporated into both the sn-1 and sn-2 positions of all the major membrane lipids tested, indicating that the endoplasmic reticulum acyltransferases do not exclude unsaturated C16 fatty acids from the sn-2 position. In addition to increases in monounsaturated and decreases in saturated fatty acids, accumulation of 16:1 was accompanied by a reduction in 18:3 in all the lipids tested except phosphatidylglycerol, and increases in 18:2 in phospholipids. Total C16 fatty acid content in the galactolipids of the transgenics was significantly higher than that in the control, but those in the phospholipids were unchanged. In transgenics, delta11 18:1 was detected in the sn-1 position of the lipids tested except phosphatidylinositol and phosphatidylserine. Introduction of the animal desaturase, controlled by a seed-specific phaseolin promoter, into soybean somatic embryo resulted in a significant reduction in saturated fatty acids. Such effects were greater in cotyledons than hypocotyl-radicles. This study demonstrated that the animal desaturase can be used to decrease the levels of saturated fatty acids in a crop plant. PMID:10907781

  17. The Genes for Cytoplasmic Ribosomal Ribonucleic Acid in Higher Plants

    PubMed Central

    Scott, N. Steele; Ingle, J.

    1973-01-01

    The genes for cytoplasmic ribosomal RNA are partially resolved from the bulk of the DNA by CsCl equilibrium centrifugation. Although in some plants the buoyant density of the ribosomal RNA genes is as expected from the base composition of ribosomal RNA, others show a large discrepancy which cannot be due to the presence of low G-C spacer-DNA. The cross-hybridization observed with 1.3 and 0.7 × 106 molecular weight ribosomal RNAs and DNA, which varies greatly with different plant species, is not due to contamination of the ribosomal RNAs, and is specific for the ribosomal DNA of each species, probably largely restricted to those sequences coding for the two stable ribosomal RNAs. The double reciprocal plot may be used for the extrapolation of saturation values only with caution, because in these cases such plots are not linear over the whole of the hybridization reaction. PMID:16658392

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  19. Selecting Rhizobium meliloti for inoculation of alfalfa planted in acid soils

    SciTech Connect

    Lowendorf, H.S.; Alexander, M.

    1983-01-01

    The study was conducted to obtain Rhizobium meliloti strains suitable for use with alfalfa grown in acid soils. Thirteen strains of R. meliloti were examined for their ability to grow in acidified culture media and seven of these were characterized for the ability to surive in acid and limed nonsterile soils or grow in the presence of the host legume, Medicago sativa L. The pH values of the most acid, defined medium that permitted growth of the bacteria from a small inoculum ranged from pH 5.3 to 6.0. For R. meliloti 411SE1 and GH1-1SE1, the minimum pH that allowed for growth, the critical pH, was not a dependable indicator of survival in a more acid medium. Strains of R. meliloti with relatively low critical pH values survived better in a limed soil but not in acid soils than strains with higher critical pH values. Three strains of R. meliloti previously identified as good inoculants for alfalfa in acid soils did not consistently survive beter than other strains in a planted or unplanted acid soil of pH 5.3. However, the plants increase the population densities of these three strains more than other strains. These results suggest that R. meliloti strains suitable for inoculation of alfalfa in acid soils may be selected not by simple saprophytic properties but by their stimulation by the host legume in acid soils.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Moussa, Tarek A A; Almaghrabi, Omar A

    2016-05-01

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

  2. High-frequency in vitro plantlet regeneration from apical bud as a novel explant of Carum copticum L.

    PubMed Central

    Salehi, Mansoureh; Hosseini, Bahman; Jabbarzadeh, Zohreh

    2014-01-01

    Objective To develop an in vitro regeneration system to increase the recovery of Carum copticum L. plantlets as a part of developing a metabolic engineering program. Methods The efficacy of different concentrations and combinations of 6-benzyladenine, indole-3-acetic acid and indole butyric acid on direct shoot regeneration and rooting of ajowan from apical bud explants were assessed. All explants were cultured on Murashige and Skoog (MS) medium supplemented with different combinations of 6-benzyl amino purine (BAP) (0, 2.2, 4.4, 8.8 µmol/L) and indole-3-acetic acid (IAA) (0, 0.5, 1.1, 2.2 µmol/L). Results The maximum shoot regeneration frequency (97.5%) and the highest number of shoots produced from apical buds (34 shoots per explant) were obtained on MS medium fortified with BAP (4.4 µmol/L) and IAA (0.5 µmol/L). Low shoot regeneration frequency was observed in BAP free treatments. The effects of different strengths of MS medium and various concentrations of IAA and indole-3- butyric acid on rooting rate, length and average number of roots were also investigated. Application of indole-3- butyric acid (6 µmol/L) in full-strength MS medium, was more effective than IAA and resulted in highest shoot regeneration frequency with the rooting rate of 100% and highest mean number of roots per shoot (41.8). The rooted plantlets were acclimatized successfully in greenhouse conditions with a survival rate of 90%. Conclusion In this study, a simple and reliable regeneration and acclimatization protocol for Carum copticum has been presented. This protocol can be found very advantageous for a variety of purposes, including mass multiplication of Carum species, medicinal plant breeding studies and transgenic plant production. PMID:25183122

  3. Lipids in salicylic acid-mediated defense in plants: focusing on the roles of phosphatidic acid and phosphatidylinositol 4-phosphate

    PubMed Central

    Zhang, Qiong; Xiao, Shunyuan

    2015-01-01

    Plants have evolved effective defense strategies to protect themselves from various pathogens. Salicylic acid (SA) is an essential signaling molecule that mediates pathogen-triggered signals perceived by different immune receptors to induce downstream defense responses. While many proteins play essential roles in regulating SA signaling, increasing evidence also supports important roles for signaling phospholipids in this process. In this review, we collate the experimental evidence in support of the regulatory roles of two phospholipids, phosphatidic acid (PA), and phosphatidylinositol 4-phosphate (PI4P), and their metabolizing enzymes in plant defense, and examine the possible mechanistic interaction between phospholipid signaling and SA-dependent immunity with a particular focus on the immunity-stimulated biphasic PA production that is reminiscent of and perhaps mechanistically connected to the biphasic reactive oxygen species (ROS) generation and SA accumulation during defense activation. PMID:26074946

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

    PubMed

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

    2013-05-01

    Hexanoic acid-induced resistance (Hx-IR) is effective against several pathogens in tomato plants. Our study of the mechanisms implicated in Hx-IR against Pseudomonas syringae pv. tomato DC3000 suggests that hexanoic acid (Hx) treatment counteracts the negative effect of coronatine (COR) and jasmonyl-isoleucine (JA-Ile) on the salicylic acid (SA) pathway. In Hx-treated plants, an increase in the expression of jasmonic acid carboxyl methyltransferase (JMT) and the SA marker genes PR1 and PR5 indicates a boost in this signalling pathway at the expense of a decrease in JA-Ile. Moreover, Hx treatment potentiates 12-oxo-phytodienoic acid accumulation, which suggests that this molecule might play a role per se in Hx-IR. These results support a positive relationship between the SA and JA pathways in Hx-primed plants. Furthermore, one of the mechanisms of virulence mediated by COR is stomatal re-opening on infection with P. syringae. In this work, we observed that Hx seems to inhibit stomatal opening in planta in the presence of COR, which suggests that, on infection in tomato, this treatment suppresses effector action to prevent bacterial entry into the mesophyll. PMID:23279078

  5. Effects of acid rain on plant microbial associations in California. Research report (final)

    SciTech Connect

    Harris, D.; Paul, E.A.

    1984-04-13

    The effects of simulated acid rain of pH 5.6 to 3.0, with ionic composition similar to that found in California, on Trifolium repens, Lupinus densiflorus and L. benthamii grown in two soils were tested. The interactions of treatment intensity, soil type, phosphorus uptake and mycorrhizal influences on growth, carbon fixation and allocation and nitrogen fixation were determined. Acidic treatments generally decreased plant growth, nodulation and nitrogenase activity. The exposure of plants to a large number of simulated rainfall conditions of shorter duration did not result in the negative growth effects. Plants adequately supplied with P, either as fertilizer or by mycorrhizal fungi, were much more resistant to conditions caused by acidic precipitation and in some cases growth increases were found.

  6. Phytotoxicity of oil sands naphthenic acids and dissipation from systems planted with emergent aquatic macrophytes.

    PubMed

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

    2008-01-01

    Differences in dissipation and phytotoxicity were measured for two naphthenic acid mixtures in hydroponically grown emergent macrophytes (Typha latifolia, Phragmites australis, and Scirpus acutus). One of the naphthenic acid (NA) mixtures was extracted from tailings pond water of an oil sands operation in Fort McMurray, Alberta, Canada. The other mixture was a commercially available NA mixture. While the oil sands NA mixture was less phytotoxic to wetland plants compared to the commercially available NA mixture, they were not sequestered by wetland plants like their commercial NA counterparts. The small loss of commercial NAs from the spiked hydroponic system appeared to be selective and dependant on the specific NA compound. The results of this study indicate that plants alone may not mitigate NAs from oil sands tailings pond water. In addition, caution should be taken when making predictions on the environmental fate of oil sands naphthenic acids when using commercial NAs as surrogates. PMID:18161556

  7. Nitro-Fatty Acids in Plant Signaling: Nitro-Linolenic Acid Induces the Molecular Chaperone Network in Arabidopsis.

    PubMed

    Mata-Pérez, Capilla; Sánchez-Calvo, Beatriz; Padilla, María N; Begara-Morales, Juan C; Luque, Francisco; Melguizo, Manuel; Jiménez-Ruiz, Jaime; Fierro-Risco, Jesús; Peñas-Sanjuán, Antonio; Valderrama, Raquel; Corpas, Francisco J; Barroso, Juan B

    2016-02-01

    Nitro-fatty acids (NO2-FAs) are the product of the reaction between reactive nitrogen species derived of nitric oxide (NO) and unsaturated fatty acids. In animal systems, NO2-FAs are considered novel signaling mediators of cell function based on a proven antiinflammatory response. Nevertheless, the interaction of NO with fatty acids in plant systems has scarcely been studied. Here, we examine the endogenous occurrence of nitro-linolenic acid (NO2-Ln) in Arabidopsis and the modulation of NO2-Ln levels throughout this plant's development by mass spectrometry. The observed levels of this NO2-FA at picomolar concentrations suggested its role as a signaling effector of cell function. In fact, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO2-Ln was involved in plant defense response against different abiotic-stress conditions, mainly by inducing heat shock proteins and supporting a conserved mechanism of action in both animal and plant defense processes. Bioinformatics analysis revealed that NO2-Ln was also involved in the response to oxidative stress conditions, mainly depicted by H2O2, reactive oxygen species, and oxygen-containing compound responses, with a high induction of ascorbate peroxidase expression. Closely related to these results, NO2-Ln levels significantly rose under several abiotic-stress conditions such as wounding or exposure to salinity, cadmium, and low temperature, thus validating the outcomes found by RNA-seq technology. Jointly, to our knowledge, these are the first results showing the endogenous presence of NO2-Ln in Arabidopsis (Arabidopsis thaliana) and supporting the strong signaling role of these molecules in the defense mechanism against different abiotic-stress situations. PMID:26628746

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

    PubMed

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

    2014-12-01

    The acid plant 'blow-down' (also called weak acid) produced at El Teniente mine in Chile was characterized. This liquid waste (tailing) is generated during the cooling and cleaning of the smelter gas prior to the production of sulfuric acid. The weak acid was composed of a liquid and a solid phase (suspended solids). The liquid phase of the sample analyzed in this study mainly contained Cu (562 mg L(-1)), SO4(2-) (32 800 mg L(-1)), Ca (1449 mg L(-1)), Fe (185 mg L(-1)), As (6 mg L(-1)), K (467 mg L(-1)) and Al (113 mg L(-1)). Additionally, the sample had a pH-value and total acidity of 0.45 and 2970 mg L(-1) as CaCO3, respectively. Hence, this waste was classified as extremely acidic and with a high metal content following the Ficklin diagram classification. Elemental analysis using atomic absorption, inductively coupled plasma, X-ray diffraction and electron microscopy showed that the suspended solids were anglesite (PbSO4) nano- and microparticles ranging from 50 nm to 500 nm in diameter. PMID:25312613

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

    NASA Technical Reports Server (NTRS)

    Mazelis, M.

    1976-01-01

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

  10. ATPase activity associated with isolated vacuoles of the crassulacean acid metabolism plant Kalanchoë daigremontiana.

    PubMed

    Smith, J A; Uribe, E G; Ball, E; Lüttge, U

    1984-10-01

    A technique is described that allows a relatively rapid and controlled isolation of vacuoles from leaves of the crassulacean acid metabolism (CAM) plant Kalanchoë daigremontiana. The method involves polybase-induced lysis of mesophyllcell protoplasts and isolation of vacuoles on a discontinuous density gradient. ATPase activity is associated with the isolated vacuoles and is not attributable to contamination by cytoplasmic constituents. It is suggested that this ATPase is responsible for the energization of malic-acid accumulation in the vacuole in CAM plants. PMID:24253162

  11. Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress

    SciTech Connect

    Lee, E.H. )

    1991-01-01

    Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the corresponding susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.

  12. Determination of free diferulic, disinapic and dicoumaric acids in plants and foods.

    PubMed

    Grúz, Jiří; Pospíšil, Jiří; Kozubíková, Hana; Pospíšil, Tomáš; Doležal, Karel; Bunzel, Mirko; Strnad, Miroslav

    2015-03-15

    Hydroxycinnamates are common phenolic compounds of plants and plant foods, often found in substantial quantities. Due to their high in vitro antioxidant activity they can easily be oxidized under oxidative conditions. In this study, we found that in vitro oxidation of coumaric, ferulic and sinapic acids resulted mainly in dimeric compounds. We hypothesized that these dimers are present in plants and plant foods not only in their bound form but also as free acids that can be extracted from non-hydrolyzed samples. By applying sensitive UHPLC-MS/MS method, we were able to identify and quantify four free hydroxycinnamic acid dimers for the first time, namely 8-8'-disinapic, 8-5'-diferulic, 8-O-4'-diferulic and 8-3'-dicoumaric acids, in wheat sprouts, Chinese cabbage, millet sprouts, light beer and parsley. Concentrations of dicinnamates in plant tissues ranged from 0.05 to 2.8 μg g(-1) DW and the monomer:dimer ratio ranged from 2 to 850. PMID:25308670

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  19. Hexanoic acid protects tomato plants against Botrytis cinerea by priming defence responses and reducing oxidative stress.

    PubMed

    Finiti, Ivan; de la O Leyva, María; Vicedo, Begonya; Gómez-Pastor, Rocío; López-Cruz, Jaime; García-Agustín, Pilar; Real, Maria Dolores; González-Bosch, Carmen

    2014-08-01

    Treatment with the resistance priming inducer hexanoic acid (Hx) protects tomato plants from Botrytis cinerea by activating defence responses. To investigate the molecular mechanisms underlying hexanoic acid-induced resistance (Hx-IR), we compared the expression profiles of three different conditions: Botrytis-infected plants (Inf), Hx-treated plants (Hx) and Hx-treated + infected plants (Hx+Inf). The microarray analysis at 24 h post-inoculation showed that Hx and Hx+Inf plants exhibited the differential expression and priming of many Botrytis-induced genes. Interestingly, we found that the activation by Hx of other genes was not altered by the fungus at this time point. These genes may be considered to be specific targets of the Hx priming effect and may help to elucidate its mechanisms of action. It is noteworthy that, in Hx and Hx+Inf plants, there was up-regulation of proteinase inhibitor genes, DNA-binding factors, enzymes involved in plant hormone signalling and synthesis, and, remarkably, the genes involved in oxidative stress. Given the relevance of the oxidative burst occurring in plant-pathogen interactions, the effect of Hx on this process was studied in depth. We showed by specific staining that reactive oxygen species (ROS) accumulation in Hx+Inf plants was reduced and more restricted around infection sites. In addition, these plants showed higher ratios of reduced to oxidized glutathione and ascorbate, and normal levels of antioxidant activities. The results obtained indicate that Hx protects tomato plants from B. cinerea by regulating and priming Botrytis-specific and non-specific genes, preventing the harmful effects of oxidative stress produced by infection. PMID:24320938

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

    PubMed

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

    2014-01-01

    The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of animal- and plant-derived amino acid mixtures, which function as skin and hair conditioning agents. The safety of α-amino acids as direct food additives has been well established, based on extensive research through acute and chronic dietary exposures and the Panel previously has reviewed the safety of individual α-amino acids in cosmetics. The Panel focused its review on dermal irritation and sensitization data relevant to the use of these ingredients in topical cosmetics. The Panel concluded that these 21 ingredients are safe in the present practices of use and concentration as used in cosmetics. PMID:25323218

  1. Nitro-Fatty Acids in Plant Signaling: Nitro-Linolenic Acid Induces the Molecular Chaperone Network in Arabidopsis1[OPEN

    PubMed Central

    Padilla, María N.; Begara-Morales, Juan C.; Luque, Francisco; Melguizo, Manuel; Fierro-Risco, Jesús; Peñas-Sanjuán, Antonio; Valderrama, Raquel

    2016-01-01

    Nitro-fatty acids (NO2-FAs) are the product of the reaction between reactive nitrogen species derived of nitric oxide (NO) and unsaturated fatty acids. In animal systems, NO2-FAs are considered novel signaling mediators of cell function based on a proven antiinflammatory response. Nevertheless, the interaction of NO with fatty acids in plant systems has scarcely been studied. Here, we examine the endogenous occurrence of nitro-linolenic acid (NO2-Ln) in Arabidopsis and the modulation of NO2-Ln levels throughout this plant’s development by mass spectrometry. The observed levels of this NO2-FA at picomolar concentrations suggested its role as a signaling effector of cell function. In fact, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO2-Ln was involved in plant defense response against different abiotic-stress conditions, mainly by inducing heat shock proteins and supporting a conserved mechanism of action in both animal and plant defense processes. Bioinformatics analysis revealed that NO2-Ln was also involved in the response to oxidative stress conditions, mainly depicted by H2O2, reactive oxygen species, and oxygen-containing compound responses, with a high induction of ascorbate peroxidase expression. Closely related to these results, NO2-Ln levels significantly rose under several abiotic-stress conditions such as wounding or exposure to salinity, cadmium, and low temperature, thus validating the outcomes found by RNA-seq technology. Jointly, to our knowledge, these are the first results showing the endogenous presence of NO2-Ln in Arabidopsis (Arabidopsis thaliana) and supporting the strong signaling role of these molecules in the defense mechanism against different abiotic-stress situations. PMID:26628746

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

    PubMed

    Tsen, Edward W J; Holtum, Joseph A M

    2012-09-01

    This study demonstrates unequivocally the presence of crassulacean acid metabolism (CAM) in a species of the Rubiaceae, the fourth largest angiosperm plant family. The tropical Australian endemic epiphytic ant-plant, Myrmecodia beccarii Hook.f., exhibits net CO(2) uptake in the dark and a concomitant accumulation of titratable acidity in plants in the field and in cultivation. Plants growing near Cardwell, in a north Queensland coastal seasonally dry forest of Melaleuca viridiflora Sol. ex Gaertn., accumulated ~50 % of their 24 h carbon gain in the dark during the warm wet season. During the transition from the wet season to the dry season, 24 h carbon gain was reduced whilst the proportion of carbon accumulated during the dark increased. By mid dry season many plants exhibited zero net carbon uptake over 24 h, but CO(2) uptake in the dark was observed in some plants following localised rainfall. In a shade-house experiment, droughted plants in which CO(2) uptake in the light was absent and dark CO(2) uptake was reduced, were able to return to relatively high rates of CO(2) uptake in the light and dark within 12 h of rewatering. PMID:22442054

  3. Influence of simulated acid snow stress on leaf tissue of wintering herbaceous plants.

    PubMed

    Inada, Hidetoshi; Nagao, Manabu; Fujikawa, Seizo; Arakawa, Keita

    2006-04-01

    Acid snow might be an environmental stress factor for wintering plants since acid precipitates are locally concentrated in snow and the period in which ice crystals are in contact with shoots might be longer than that of acid precipitates in rain. In this study, 'equilibrium' and 'prolonged' freezing tests with sulfuric acid, which simulate situations of temperature depression and chronic freezing at a subzero temperature with acid precipitate as acid snow stress, respectively, were carried out using leaf segments of cold-acclimated winter wheat. When leaf segments were frozen in the presence of sulfuric acid solution (pH 4.0, 3.0 or 2.0) by equilibrium freezing with ice seeding, the survival rate of leaf samples treated with sulfuric acid solution of pH 2.0 decreased markedly. Leaf samples after supercooling to -4 and -8 degrees C in the presence of sulfuric acid solution (pH 2.0) without ice seeding were less damaged. When leaf samples were subjected to prolonged freezing at -4 and -8 degrees C for 7 d with sulfuric acid (pH 2.0), the survival rates of leaf samples exposed to sulfuric acid decreased more than those of leaf samples treated with water. On the other hand, leaf samples were less damaged by prolonged supercooling at -4 and -8 degrees C for 7 d with sulfuric acid (pH 2.0). The results suggest that an acid condition (pH 2.0) in the process of extracellular freezing and/or thawing promotes freezing injury of wheat leaves. PMID:16481360

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

    PubMed

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

    2015-01-01

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

  5. Fatty acid profile of 25 plant oils and implications for industrial applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fatty acid (FA) profiles of plant oils extracted from twenty-five alternative feedstocks were determined. This information was utilized to determine what industrial application(s) each oil is best suited for. The basis for the selection was the premise that FA composition influences properties o...

  6. A Continuous, Quantitative Fluorescent Assay for Plant Caffeic acid O-Methyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant caffeic acid O-methyltransferases (COMTs) use s-adenosylmethionine (ado-met), as a methyl donor to transmethylate their preferred (phenolic) substrates in-vivo, and will generally utilize a range of phenolic compounds in-vitro. Collazo et al. (2005; Analytical Biochemistry 342: 86-92) have pu...

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Cost analysis of phosphoric acid fuel cell power plant includes two parts: a method for estimation of system capital costs, and an economic analysis which determines the levelized annual cost of operating the system used in the capital cost estimation. A FORTRAN computer has been developed for this cost analysis.

  8. 77 FR 48433 - New Source Performance Standards Review for Nitric Acid Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... Federal Register on December 23, 1971 (36 FR 24881). The first review of the Nitric Acid Plants NSPS was completed on June 19, 1979 (44 FR 35265). An additional review was completed on April 5, 1984 (49 FR 13654... were made during three reviews since the original promulgation in 1971 (October 6, 1975 (40 FR...

  9. 76 FR 63878 - New Source Performance Standards Review for Nitric Acid Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ..., Subpart G) were promulgated in the Federal Register on December 23, 1971 (36 FR 24881). The first review of the Nitric Acid Plants NSPS was completed on June 19, 1979 (44 FR 35265). An additional review was completed on April 5, 1984 (49 FR 13654). No changes were made to the NSPS as a result of those...

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

    PubMed

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

    2013-12-01

    The optical beam deflection method was applied to study the effects of acid solution on both a terrestial and aquatic plants Egeria and Cerastium, which are common aquatic plant and terrestial weed respectively. A probe beam from a He-Ne laser was passed through a vicinity of a leaf of the plants, which were put in culture dishes filled with acid solutions. Deflection signals of the probe beam were monitored and compared for acid solutions with different pH values. The results of Egria showed that the deflection signals changed dramatically when pH values of acid solutions were 2.0 and 3.0, while little at pH of 4.0 and 5.0. For Cerastium when pH were below 3.0, deflection signals changed greatly with time at the begining. After a certain period of time, deflection signals changed little with time. When pH value was above 4.0, deflection signals of Cerastium were still changing with time even after 20 hours. The results suggested that the damage threshold of pH was between 3.0 and 4.0 for both the land and aquatic plants. PMID:25078849

  11. Microwave-Assisted Solvent Extraction and Analysis of Shikimic Acid from Plant Tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple method using microwave-assisted extraction (MWAE) using water as the extraction solvent was developed for the determination of shikimic acid in plant tissue of Brachiaria decumbens Stapf, an important Poaceae forage and weed species widely spread in agricultural and non-agricultural areas t...

  12. Active magnetic regenerator

    DOEpatents

    Barclay, John A.; Steyert, William A.

    1982-01-01

    The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

  13. Selection of an acid-gas removal process for an LNG plant

    SciTech Connect

    Stone, J.B.; Jones, G.N.; Denton, R.D.

    1996-12-31

    Acid gas contaminants, such as, CO{sub 2}, H{sub 2}S and mercaptans, must be removed to a very low level from a feed natural gas before it is liquefied. CO{sub 2} is typically removed to a level of about 100 ppm to prevent freezing during LNG processing. Sulfur compounds are removed to levels required by the eventual consumer of the gas. Acid-gas removal processes can be broadly classified as: solvent-based, adsorption, cryogenic or physical separation. The advantages and disadvantages of these processes will be discussed along with design and operating considerations. This paper will also discuss the important considerations affecting the choice of the best acid-gas removal process for LNG plants. Some of these considerations are: the remoteness of the LNG plant from the resource; the cost of the feed gas and the economics of minimizing capital expenditures; the ultimate disposition of the acid gas; potential for energy integration; and the composition, including LPG and conditions of the feed gas. The example of the selection of the acid-gas removal process for an LNG plant.

  14. Application of boric acid baits to plant foliage for adult mosquito control.

    PubMed

    Xue, Rui-De; Kline, Daniel L; Ali, Arshad; Barnard, Donald R

    2006-09-01

    Boric acid (1%) in 5% sugar water bait solution was applied as a spray to the foliage, stems, and other surfaces of plants for control of adult Aedes albopictus, Culex nigripalpus, and Ochlerotatus taeniorhynchus. Initial studies outdoors in small (1.42-m3) screened cages showed that exposure of male and female mosquitoes to 1% boric acid bait for 48 h resulted in 80 to 100% mortality in Ae. albopictus and > or = 98% mortality in Cx. nigripalpus and Oc. taeniorhynchus. At 48 h posttreatment, in large (1,178-m3) outdoor screened cages, 1% boric acid bait applied as a spray to plant surfaces significantly reduced the landing rates of Ae. albopictus and Cx. nigripalpus on a human subject as well as the numbers of these two species captured in mechanical traps, compared with responses for adults exposed to 5% sugar water solution only (control). Boric acid bait treatments in large screened cages did not significantly reduce landing rates or trap captures of Oc. taeniorhynchus. The application of boric acid baits to plant surfaces may be an effective adulticidal method for selected species of pest and disease vector mosquitoes. PMID:17067052

  15. In Vitro Propagation of Cannabis sativa L. and Evaluation of Regenerated Plants for Genetic Fidelity and Cannabinoids Content for Quality Assurance.

    PubMed

    Lata, Hemant; Chandra, Suman; Khan, Ikhlas A; ElSohly, Mahmoud A

    2016-01-01

    Cannabis sativa L. (Marijuana; Cannabaceae), one of the oldest medicinal plants in the world, has been used throughout history for fiber, food, as well as for its psychoactive properties. The dioecious and allogamous nature of C. sativa is the major constraint to maintain the consistency in chemical profile and overall efficacy if grown from seed. Therefore, the present optimized in vitro propagation protocol of the selected elite germplasm via direct organogenesis and quality assurance protocols using genetic and chemical profiling provide an ideal pathway for ensuring the efficacy of micropropagated Cannabis sativa germplasm. A high frequency shoot organogenesis of C. sativa was obtained from nodal segments in 0.5 μM thidiazuron medium and 95 % in vitro rhizogenesis is obtained on half-strength MS medium supplemented with 500 mg/L activated charcoal and 2.5 μM indole-3-butyric acid. Inter Simple Sequence Repeats (ISSR) and Gas Chromatography-Flame Ionization Detection (GC-FID) are successfully used to monitor the genetic stability in micropropagated plants up to 30 passages in culture and hardened in soil for 8 months. PMID:27108324

  16. Mixture Screening and Mixture-Amount Designs to Determine Plant Growth Regulator Effects on Shoot Regeneration from Grapefruit (Citrus paradisi Macf.) Epicotyls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to improve shoot regeneration from grapefruit epicotyl explants since some important in vitro applications in citrus, such as Agrobacterium-mediated transformation, commonly use epicotyl segments from in vitro seedlings; adequate adventitious shoot production is thus...

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

    PubMed

    Baccelli, Ivan; Mauch-Mani, Brigitte

    2016-08-01

    Plants are exposed to recurring biotic and abiotic stresses that can, in extreme situations, lead to substantial yield losses. With the changing environment, the stress pressure is likely to increase and sustainable measures to alleviate the effect on our crops are sought. Priming plants for better stress resistance is one of the sustainable possibilities to reach this goal. Here, we report on the effects of beta-aminobutyric acid, a priming agent with an exceptionally wide range of action and describe its way of preparing plants to defend themselves against various attacks, among others through the modulation of their hormonal defense signaling, and highlight the special role of abscisic acid in this process. PMID:26584561

  18. Effects of acid precipitation on reproduction in alpine plant species. [Erythronium grandiflorum; Aquilegia caerulea

    SciTech Connect

    McKenna, M.A.; Hille-Salgueiro, M.; Musselman, R.C. Dept. of Agriculture, Fort Collins, CO )

    1990-01-01

    A series of experiments were designed to determine the impact of acid rain on plant reproductive processes, a critical component of a species life history. Research was carried out in herbaceous alpine communities at the USDA (United States Department of Agriculture) Forest Service Glacier Lakes Ecosystem Experiments Site in the Snowy Mts. of Wyoming. A range of species were surveyed to monitor the sensitivity of pollen to acidification during germination and growth, and all species demonstrated reduced in vitro pollen germination in acidified media. Field pollinations were carried out in Erythronium grandiflorum and Aquilegia caerulea to determine the reproductive success of plants exposed to simulated ambient precipitation (pH 5.6) or simulated acid precipitation (pH 3.6) prior to pollination. In Erythronium, no differences were observed in seed set and seed weight of fruits resulting from the two pollination treatments. In Aquilegia, fruits resulting from the acid spray treatment produced fewer seeds and lighter seeds.

  19. In vitro regeneration and ploidy level analysis of Eulophia ochreata Lindl.

    PubMed

    Shriram, Varsha; Nanekar, Vikas; Kumar, Vinay; Kavi Kishor, P B

    2014-11-01

    Various parameters including explant-type, medium compositions, use of phytohormones and additives were optimized for direct and indirect regeneration of E. ochreata, a medicinal orchid under threat. Protocorm-like-bodies (PLBs) proved to be the best explants for shoot initiation, proliferation and callus induction. Murashige and Skoog's (MS) medium containing 2.5 mg L(-1) 6-benzylaminopurine (BAP), 1.0 mg L(-1) kinetin (Kin) and additives (adenine sulfate, arginine, citric acid, 30 mg L(-1) each and 50 mg L(-1) ascorbic acid) was optimal for shoot multiplication (12.1 shoots and 7.1 PLBs per explant with synchronized growth), which also produced callus. Shoot number was further increased with three successive subcultures on same media and approximately 40 shoots per explant were achieved after 3 cycles of 30 days each. Additives and casein hydrolysate (CH) showed advantageous effects on indirect shoot regeneration via protocorm-derived callus. Optimum indirect regeneration was achieved on MS containing additives, 500 mg L(-1) CH, 2.5 mg L(-1) BAP and 1.0 mg L(-1) Kin with 30 PLBs and 6 shoots per callus mass (approximately 5 mm size). The shoots were rooted (70% frequency) on one by fourth-MS medium containing 2.0 mg L(-1) indole-3-butyric acid, 200 mg L(-1) activated charcoal and additives. The rooted plantlets were hardened and transferred to greenhouse with 63% survival rate. Flow-cytometry based DNA content analysis revealed that the ploidy levels were maintained in in vitro regenerated plants. This is the first report for in vitro plant regeneration in E. ochreata. PMID:25434107

  20. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    PubMed Central

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  1. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci.

    PubMed

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles-especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  2. Plant Hormone Salicylic Acid Produced by a Malaria Parasite Controls Host Immunity and Cerebral Malaria Outcome

    PubMed Central

    Matsubara, Ryuma; Aonuma, Hiroka; Kojima, Mikiko; Tahara, Michiru; Andrabi, Syed Bilal Ahmad; Sakakibara, Hitoshi; Nagamune, Kisaburo

    2015-01-01

    The apicomplexan parasite Toxoplasma gondii produces the plant hormone abscisic acid, but it is unclear if phytohormones are produced by the malaria parasite Plasmodium spp., the most important parasite of this phylum. Here, we report detection of salicylic acid, an immune-related phytohormone of land plants, in P. berghei ANKA and T. gondii cell lysates. However, addition of salicylic acid to P. falciparum and T. gondii culture had no effect. We transfected P. falciparum 3D7 with the nahG gene, which encodes a salicylic acid-degrading enzyme isolated from plant-infecting Pseudomonas sp., and established a salicylic acid-deficient mutant. The mutant had a significantly decreased concentration of parasite-synthesized prostaglandin E2, which potentially modulates host immunity as an adaptive evolution of Plasmodium spp. To investigate the function of salicylic acid and prostaglandin E2 on host immunity, we established P. berghei ANKA mutants expressing nahG. C57BL/6 mice infected with nahG transfectants developed enhanced cerebral malaria, as assessed by Evans blue leakage and brain histological observation. The nahG-transfectant also significantly increased the mortality rate of mice. Prostaglandin E2 reduced the brain symptoms by induction of T helper-2 cytokines. As expected, T helper-1 cytokines including interferon-γ and interleukin-2 were significantly elevated by infection with the nahG transfectant. Thus, salicylic acid of Plasmodium spp. may be a new pathogenic factor of this threatening parasite and may modulate immune function via parasite-produced prostaglandin E2. PMID:26466097

  3. Hepatoprotective Effects of Schisandra sphenanthera Extract against Lithocholic Acid-Induced Cholestasis in Male Mice Are Associated with Activation of the Pregnane X Receptor Pathway and Promotion of Liver Regeneration.

    PubMed

    Zeng, Hang; Li, Dongshun; Qin, Xiaoling; Chen, Pan; Tan, Huasen; Zeng, Xuezhen; Li, Xi; Fan, Xiaomei; Jiang, Yiming; Zhou, Yawen; Chen, Yixin; Wang, Ying; Huang, Min; Bi, Huichang

    2016-03-01

    We previously reported that the ethanol extract of Schisandra sphenanthera [Wuzhi (WZ) tablet] significantly protects against acetaminophen-induced hepatoxicity. However, whether WZ exerts a protective effect against cholestasis remains unclear. In this study, the protective effect of WZ on lithocholic acid (LCA)-induced intrahepatic cholestasis in mice was characterized and the involved mechanisms were investigated. WZ pretreatment (350 mg/kg) with LCA significantly reversed liver necrosis and decreased serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activity. More importantly, serum total bile acids and total bilirubin were also remarkably reduced. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis showed that hepatic expression of pregnane X receptor (PXR) target genes such as CYP3A11 and UDP-glucuronosyltransferase (UGT) 1A1 were significantly increased by WZ treatment. Luciferase assays performed in LS174T cells illustrated that WZ extract and its six bioactive lignans could all activate human PXR. In addition, WZ treatment significantly promoted liver regeneration via inhibition of p53/p21 to induce cell proliferation-associated proteins such as cyclin D1 and proliferating cell nuclear antigen. In conclusion, WZ has a protective effect against LCA-induced intrahepatic cholestasis, partially owing to activation of the PXR pathway and promotion of liver regeneration. PMID:26658429

  4. Plant-bacteria bioremediation agents affect the response of plant bioindicators independent of 2-chlorobenzoic acid degradation

    SciTech Connect

    Siciliano, S.D.; Germida, J.J.

    1995-12-31

    Plants are known to degrade toxicants in soil and are potentially useful bioremediation agents. The authors developed plant-bacteria associations (e.g., Meadow brome [Bromus riparius] and Pseudomonas aeruginosa strain R75) that degrade 2-chlorobenzoic acid (2CBA) in soil, and assessed their success using Slender wheatgrass (Agropyron trachycaulum) germination as a bioindicator of 2CBA levels. Gas chromatography was used to chemically assess 2CBA levels. Specific plant-bacteria bioremediation treatments decreased soil 2CBA levels by 17 to 52%, but bioindicator response did not correspond to chemical analysis. Contaminated and uncontaminated soil was subjected to bioremediation treatments. After 42 days, uncontaminated soil was collected and amended to various 2CBA levels. This soil and the remediated soil were analyzed by the plant bioindicator and gas chromatography. Bioremediation treatments altered germination of Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass at low 2CBA levels, but increased the toxicity of 2CBA at high 2CBA levels. For example, germination in soil subjected to the Meadow brome and R75 treatment was increased by ca. 30% at 50 mg kg{sup {minus}1} 2CBA, but decreased by ca. 50% at 150 mg kg{sup {minus}1} 2CBA. The results indicate that specific plant-bacteria bioremediation treatments affect plant bioindicator response independent of 2CBA degradation, and may confound efforts to determine the toxicity of 2CBA in soil.

  5. Screening molecules for control of citrus huanglongbing using an optimized regeneration system for 'Candidatus Liberibacter asiaticus'-infected periwinkle (Catharanthus roseus) cuttings.

    PubMed

    Zhang, Muqing; Duan, Yongping; Zhou, Lijuan; Turechek, William W; Stover, Ed; Powell, Charles A

    2010-03-01

    Citrus huanglongbing is one of the most destructive diseases of citrus worldwide. The disease is associated with three different species of 'Candidatus Liberibacter', of which 'Ca. L. asiaticus' is the most widely distributed. An optimized system using 'Ca. L. asiaticus'-infected periwinkle cuttings was developed to screen chemical compounds effective for controlling the bacterial population while simultaneously assessing their phytotoxicity. The optimal regeneration conditions were determined to be the use of vermiculite as a growth medium for the cuttings, and a fertilization routine using half-strength Murashige and Tucker medium supplemented with both naphthalene acetic acid (4 microg/ml) and indole-3-butyric acid (4 microg/ml). This system allowed a plant regeneration rate of 60.6% for 'Ca. L. asiaticus'-infected cuttings in contrast to the <1% regeneration rate with water alone. Two chemical agents, penicillin G sodium and 2,2-dibromo-3-nitrilopropionamide (DBNPA), were found to be effective at eliminating or suppressing the 'Ca. L. asiaticus' bacterium in this periwinkle regeneration system. When treated with penicillin G sodium at 50 microg/ml, all plants regenerated from 'Ca. L. asiaticus'-infected cuttings were 'Ca. L. asiaticus' negative as determined by both nested polymerase chain reaction (PCR) and quantitative real-time PCR. In addition, DBNPA was also able to significantly reduce the percentage of 'Ca. L. asiaticus'-positive plants and the titer of the 'Ca. L. asiaticus' bacterium at 200 microl/liter. PMID:20128697

  6. Multiple interactions of NaHER1 protein with abscisic acid signaling in Nicotiana attenuata plants

    PubMed Central

    Dinh, Son Truong; Baldwin, Ian T; Gális, Ivan

    2013-01-01

    Previously, we identified a novel herbivore elicitor-regulated protein in Nicotiana attenuata (NaHER1) that is required to suppress abscisic acid (ABA) catabolism during herbivore attack and activate a full defense response against herbivores. ABA, in addition to its newly defined role in defense activation, mainly controls seed germination and stomatal function of land plants. Here we show that N. attenuata seeds silenced in the expression of NaHER1 by RNA interference (irHER1) accumulated less ABA during germination, and germinated faster on ABA-containing media compared to WT. Curiously, epidermal cells of irHER1 plants were wrinkled, possibly due to the previously demonstrated increase in transpiration of irHER1 plants that may affect turgor and cause wrinkling of the cells. We conclude that NaHER1 is a highly pleiotropic regulator of ABA responses in N. attenuata plants. PMID:24022276

  7. An Integrated Strategy to Identify Key Genes in Almond Adventitious Shoot Regeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant genetic transformation usually depends on efficient adventitious regeneration systems. In almond (Prunus dulcis Mill.), regeneration of transgenic adventitious shoots was achieved but with low efficiency. Histological studies identified two main stages of organogenesis in almond explants that ...

  8. Jasmonate-inducible plant enzymes degrade essential amino acids in the herbivore midgut

    PubMed Central

    Chen, Hui; Wilkerson, Curtis G.; Kuchar, Jason A.; Phinney, Brett S.; Howe, Gregg A.

    2005-01-01

    The plant hormone jasmonic acid (JA) activates host defense responses against a broad spectrum of herbivores. Although it is well established that JA controls the expression of a large set of target genes in response to tissue damage, very few gene products have been shown to play a direct role in reducing herbivore performance. To test the hypothesis that JA-inducible proteins (JIPs) thwart attack by disrupting digestive processes in the insect gut, we used a MS-based approach to identify host proteins that accumulate in the midgut of Manduca sexta larvae reared on tomato (Solanum lycopersicum) plants. We show that two JIPs, arginase and threonine deaminase (TD), act in the M. sexta midgut to catabolize the essential amino acids Arg and Thr, respectively. Transgenic plants that overexpress arginase were more resistant to M. sexta larvae, and this effect was correlated with reduced levels of midgut Arg. We present evidence indicating that the ability of TD to degrade Thr in the midgut is enhanced by herbivore-induced proteolytic removal of the enzyme's C-terminal regulatory domain, which confers negative feedback regulation by isoleucine in planta. Our results demonstrate that the JA signaling pathway strongly influences the midgut protein content of phytophagous insects and support the hypothesis that catabolism of amino acids in the insect digestive tract by host enzymes plays a role in plant protection against herbivores. PMID:16357201

  9. Functional analyses of carnivorous plant-specific amino acid residues in S-like ribonucleases.

    PubMed

    Arai, Naoki; Nishimura, Emi; Kikuchi, Yo; Ohyama, Takashi

    2015-09-11

    Unlike plants with no carnivory, carnivorous plants seem to use S-like ribonucleases (RNases) as an enzyme for carnivory. Carnivorous plant-specific conserved amino acid residues are present at four positions around the conserved active site (CAS). The roles of these conserved amino acid residues in the enzymatic function were explored in the current study by preparing five recombinant variants of DA-I, the S-like RNase of Drosera adelae. The kcat and kcat/Km values of the enzymes revealed that among the four variants with a single mutation, the serine to glycine mutation at position 111 most negatively influenced the enzymatic activity. The change in the bulkiness of the amino acid residue side-chain seemed to be the major cause of the above effect. Modeling of the three dimensional (3D) structures strongly suggested that the S to G mutation at 111 greatly altered the overall enzyme conformation. The conserved four amino acid residues are likely to function in keeping the two histidine residues, which are essential for the cleavage of RNA strands, and the CAS in the most functional enzymatic conformation. PMID:26235877

  10. Characteristics of dioxin emissions from a Waelz plant with acid and basic kiln mode.

    PubMed

    Hung, Pao Chen; Chi, Kai Hsien; Chen, Mei Lien; Chang, Moo Been

    2012-01-30

    The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in the flue gas of a Waelz plant operated in acid and basic modes, respectively. To abate (PCDD/F) and other pollutants, the plant operates with a post-treatment of flue gases by activated carbon injection and subsequent filtration. Relatively high PCDD/F discharge by fly ashes is found with acid kiln mode of the Waelz process. Therefore, basic kiln mode of the Waelz process is investigated and compared in this plant. With the adsorbent injection rate of 7 kg/h (95 mg/Nm(3)), the PCDD/F concentration in stack gas was measured as 0.123 ng I-TEQ/Nm(3) in the basic operating mode. The added Ca(OH)(2) reacted with metal catalysts and HCl((g)) in the flue gas and thus effectively suppressed the formation of PCDD/Fs. PCDD/F concentrations in fly ashes sampled from the dust settling chamber, cyclone, primary filter and secondary filter in basic kiln mode were significantly lower than that in acid kiln mode. Total PCDD/F emission on the basis of treating one kg of electric arc furnace dust in the basic operation mode was 269 ng I-TEQ/kg EAF-dust treated which was significantly lower than that in acid mode (640 ng I-TEQ/kg EAF-dust treated). PMID:22178278

  11. Effects of acid rain, alone and in combination with gaseous pollutants, on growth and yield of crop plants

    SciTech Connect

    Shriner, D.S.; Johnston, J.W. Jr.

    1985-01-01

    Greenhouse, growth chamber, and field experiments were conducted to determine the response of crop plants to levels of acidity in simulated rain. The major objectives were: to determine the levels of acidity in rain that alter crop productivity; to evaluate varietal differences in crop response; and to determine the response of crop plants to the combined stress of acid rain and gaseous pollutants, primarily ozone. Results showed additive effects rather than synergistic ones.

  12. Defense signaling among interconnected ramets of a rhizomatous clonal plant, induced by jasmonic-acid application

    NASA Astrophysics Data System (ADS)

    Chen, Jin-Song; Lei, Ning-Fei; Liu, Qing

    2011-07-01

    Resource sharing between ramets of clonal plants is a well-known phenomenon that allows stoloniferous and rhizomatous species to internally transport water, mineral nutrients and carbohydrates from sites of high supply to sites of high demand. Moreover, vascular ramet connections are likely to provide an excellent means to share substances other than resources, such as defense signals. In a greenhouse experiment, the rhizomatous sedge Carex alrofusca, consisting of integrated ramets of different ages, was used to study the transmission of defense signals through belowground rhizome connections in response to local spray with jasmonic-acid. A feeding preference test with the caterpillar Gynaephora rnenyuanensis was employed to assess benefits of rhizome connections on defense signaling. Young ramets were more responsive to jasmonic-acid treatment than middle-aged or old ramets. Condensed tannin content in the foliage of young ramets showed a significant increase and soluble carbohydrate and nitrogen content showed marginally significant decreases in the 1 mM jasmonic-acid treatment but not in control and/or 0.0001 mM jasmonic-acid treatments. The caterpillar G. rnenyuanensis preferentially grazed young ramets. After a localized spray of 1 mM jasmonic-acid, the leaf area of young ramets consumed by herbivores was greatly reduced. We propose that defense signals may be transmitted through physical connections (stolon or rhizome) among interconnected ramets of clonal plants. Induced resistance to herbivory may selectively enhance the protection of more vulnerable and valuable plant tissues and confer a significant benefit to clonal plants by a modular risk-spreading strategy, equalizing ontogenetic differences of unevenly-aged ramets in chemical defense compounds and nutritional properties of tissue.

  13. The synthesis and accumulation of stearidonic acid in transgenic plants: a novel source of 'heart-healthy' omega-3 fatty acids.

    PubMed

    Ruiz-López, Noemí; Haslam, Richard P; Venegas-Calerón, Mónica; Larson, Tony R; Graham, Ian A; Napier, Johnathan A; Sayanova, Olga

    2009-09-01

    Dietary omega-3 polyunsaturated fatty acids have a proven role in reducing the risk of cardiovascular disease and precursor disease states such as metabolic syndrome. Although most studies have focussed on the predominant omega-3 fatty acids found in fish oils (eicosapentaenoic acid and docosahexaenoic acid), recent evidence suggests similar health benefits from their common precursor, stearidonic acid. Stearidonic acid is a Delta6-unsaturated C18 omega-3 fatty acid present in a few plant species (mainly the Boraginaceae and Primulaceae) reflecting the general absence of Delta6-desaturation from higher plants. Using a Delta6-desaturase from Primula vialii, we generated transgenic Arabidopsis and linseed lines accumulating stearidonic acid in their seed lipids. Significantly, the P. vialiiDelta6-desaturase specifically only utilises alpha-linolenic acid as a substrate, resulting in the accumulation of stearidonic acid but not omega-6 gamma-linolenic acid. Detailed lipid analysis revealed the accumulation of stearidonic acid in neutral lipids such as triacylglycerol but an absence from the acyl-CoA pool. In the case of linseed, the achieved levels of stearidonic acid (13.4% of triacylglycerols) are very similar to those found in the sole natural commercial plant source (Echium spp.) or transgenic soybean oil. However, both those latter oils contain gamma-linolenic acid, which is not normally present in fish oils and considered undesirable for heart-healthy applications. By contrast, the stearidonic acid-enriched linseed oil is essentially devoid of this fatty acid. Moreover, the overall omega-3/omega-6 ratio for this modified linseed oil is also significantly higher. Thus, this nutritionally enhanced linseed oil may have superior health-beneficial properties. PMID:19702757

  14. Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

  15. 78 FR 15753 - Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... COMMISSION Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power..., DG-1269 ``Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear... lead-acid storage batteries in nuclear power plants. DATES: Submit comments by May 13, 2013....

  16. 1-aminocyclopropane-1-carboxylic acid (ACC) in plants: more than just the precursor of ethylene!

    PubMed Central

    Van de Poel, Bram; Van Der Straeten, Dominique

    2014-01-01

    Ethylene is a simple two carbon atom molecule with profound effects on plants. There are quite a few review papers covering all aspects of ethylene biology in plants, including its biosynthesis, signaling and physiology. This is merely a logical consequence of the fascinating and pleiotropic nature of this gaseous plant hormone. Its biochemical precursor, 1-aminocyclopropane-1-carboxylic acid (ACC) is also a fairly simple molecule, but perhaps its role in plant biology is seriously underestimated. This triangularly shaped amino acid has many more features than just being the precursor of the lead-role player ethylene. For example, ACC can be conjugated to three different derivatives, but their biological role remains vague. ACC can also be metabolized by bacteria using ACC-deaminase, favoring plant growth and lowering stress susceptibility. ACC is also subjected to a sophisticated transport mechanism to ensure local and long-distance ethylene responses. Last but not least, there are now a few exciting studies where ACC has been reported to function as a signal itself, independently from ethylene. This review puts ACC in the spotlight, not to give it the lead-role, but to create a picture of the stunning co-production of the hormone and its precursor. PMID:25426135

  17. Theroa zethus Caterpillars Use Acid Secretion of Anti-Predator Gland to Deactivate Plant Defense

    PubMed Central

    Dussourd, David E.

    2015-01-01

    In North America, notodontid caterpillars feed almost exclusively on hardwood trees. One notable exception, Theroa zethus feeds instead on herbaceous plants in the Euphorbiaceae protected by laticifers. These elongate canals follow leaf veins and contain latex under pressure; rupture causes the immediate release of sticky poisonous exudate. T. zethus larvae deactivate the latex defense of poinsettia and other euphorbs by applying acid from their ventral eversible gland, thereby creating furrows in the veins. The acid secretion softens the veins allowing larvae to compress even large veins with their mandibles and to disrupt laticifers internally often without contacting latex. Acid secretion collected from caterpillars and applied to the vein surface sufficed to create a furrow and to reduce latex exudation distal to the furrow where T. zethus larvae invariably feed. Larvae with their ventral eversible gland blocked were unable to create furrows and suffered reduced growth on poinsettia. The ventral eversible gland in T. zethus and other notodontids ordinarily serves to deter predators; when threatened, larvae spray acid from the gland orifice located between the mouthparts and first pair of legs. To my knowledge, T. zethus is the first caterpillar found to use an antipredator gland for disabling plant defenses. The novel combination of acid application and vein constriction allows T. zethus to exploit its unusual latex-bearing hosts. PMID:26517872

  18. Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

    PubMed

    Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

    2016-02-20

    In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed. PMID:26779817

  19. Nucleic acids encoding plant glutamine phenylpyruvate transaminase (GPT) and uses thereof

    DOEpatents

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-03-29

    Glutamine phenylpyruvate transaminase (GPT) proteins, nucleic acid molecules encoding GPT proteins, and uses thereof are disclosed. Provided herein are various GPT proteins and GPT gene coding sequences isolated from a number of plant species. As disclosed herein, GPT proteins share remarkable structural similarity within plant species, and are active in catalyzing the synthesis of 2-hydroxy-5-oxoproline (2-oxoglutaramate), a powerful signal metabolite which regulates the function of a large number of genes involved in the photosynthesis apparatus, carbon fixation and nitrogen metabolism.

  20. The molecular path to in vitro shoot regeneration.

    PubMed

    Motte, Hans; Vereecke, Danny; Geelen, Danny; Werbrouck, Stefaan

    2014-01-01

    Plant regeneration through de novo shoot organogenesis in tissue culture is a critical step in most plant transformation and micropropagation procedures. Establishing an efficient regeneration protocol is an empirical process and requires optimization of multiple factors that influence the regeneration capacity. Here, we review the molecular process of shoot induction in a two-step regeneration protocol and focus on the role of auxins and cytokinins. First, during incubation on an auxin-rich callus induction medium (CIM), organogenic callus is produced that exhibits characteristics of a root meristem. Subsequent incubation on a cytokinin-rich shoot induction medium (SIM) induces root to shoot conversion. Through a detailed analysis of the different aspects of shoot regeneration, we try to reveal hinge points and novel candidate genes that may be targeted to increase shoot regeneration capacity in order to improve transformation protocols. PMID:24355763

  1. Antitumor-promoting activity of scopadulcic acid B, isolated from the medicinal plant Scoparia dulcis L.

    PubMed

    Nishino, H; Hayashi, T; Arisawa, M; Satomi, Y; Iwashima, A

    1993-01-01

    Scopadulcic acid B (SDB), a tetracyclic diterpenoid isolated from a medicinal plant, Scoparia dulcis L., inhibited the effects of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in vitro and in vivo; SDB inhibited TPA-enhanced phospholipid synthesis in cultured cells, and also suppressed the promoting effect of TPA on skin tumor formation in mice initiated with 7,12-dimethylbenz[a]anthracene. The potency of SDB proved to be stronger than that of other natural antitumor-promoting terpenoids, such as glycyrrhetinic acid. PMID:8451033

  2. Jasmonic acid interacts with abscisic acid to regulate plant responses to water stress conditions

    PubMed Central

    de Ollas, Carlos; Arbona, Vicent; Gómez-Cadenas, Aurelio

    2015-01-01

    Phytohormones are key players in signaling environmental stress conditions. Hormone profiling together with proline accumulation were studied in leaves and roots of different mutant lines of Arabidopsis. Regulation of proline accumulation in this system seems complex and JA-deficient (jar1-1) and JA-insensitive (jai1) lines accumulating high levels of proline despite their very low ABA levels seems to discard an ABA-dependent response. However, the pattern of proline accumulation in jai1 seedlings parallels that of ABA. Under stress conditions, there is an opposite pattern of ABA accumulation in roots of jar1-1/coi1-16 (in which ABA only slightly increase) and jai1 (in which ABA increase is even higher than in WT plants). This also makes JA-ABA crosstalk complex and discards any lineal pathway that could explain this hormonal interaction. PMID:26340066

  3. Jasmonic acid interacts with abscisic acid to regulate plant responses to water stress conditions.

    PubMed

    de Ollas, Carlos; Arbona, Vicent; Gómez-Cadenas, Aurelio

    2015-01-01

    Phytohormones are key players in signaling environmental stress conditions. Hormone profiling together with proline accumulation were studied in leaves and roots of different mutant lines of Arabidopsis. Regulation of proline accumulation in this system seems complex and JA-deficient (jar1-1) and JA-insensitive (jai1) lines accumulating high levels of proline despite their very low ABA levels seems to discard an ABA-dependent response. However, the pattern of proline accumulation in jai1 seedlings parallels that of ABA. Under stress conditions, there is an opposite pattern of ABA accumulation in roots of jar1-1/coi1-16 (in which ABA only slightly increase) and jai1 (in which ABA increase is even higher than in WT plants). This also makes JA-ABA crosstalk complex and discards any lineal pathway that could explain this hormonal interaction. PMID:26340066

  4. Novel regeneration method for phosphate loaded granular ferric (hydr)oxide--a contribution to phosphorus recycling.

    PubMed

    Kunaschk, Marco; Schmalz, Viktor; Dietrich, Norman; Dittmar, Thomas; Worch, Eckhard

    2015-03-15

    At a progressive rate, small wastewater treatment plants in rural areas need to be equipped with an additional phosphorus removal stage in order to achieve a good chemical status in the receiving natural water bodies. A conventional regeneration method for ferric (hydr)oxides such as phosphate specific adsorbents, which can be applied to remove and recover phosphorus in fixed bed filters, was investigated and improved. It was shown that a loss of up to 85% of the initial capacity can be observed when regeneration with 1 M NaOH is implemented. The losses are caused by surface blocking with different calcium-containing compounds as revealed by an EDX analysis. These blocking compounds could be removed completely with an additional acidic regeneration step at pH = 2.5. During the alkaline desorption that followed, complete phosphorus removal and a full recovery of the adsorption capacity were achieved for goethite-rich Bayoxide(®) E 33 HC (E33HC) and akaganéite-rich GEH(®) 104 (GEH). The regeneration procedure was repeated up to eight times without any signs of further decline in the phosphate adsorption capacity or any changes in the specific surface area or pore size distribution of the adsorbent. In contrast to GEH and E33HC, ferric hydroxide- and calcite-rich FerroSorp(®) Plus (FSP) was partly dissolved during acid treatment. PMID:25618522

  5. Biomaterials for periodontal regeneration

    PubMed Central

    Shue, Li; Yufeng, Zhang; Mony, Ullas

    2012-01-01

    Periodontal disease is characterized by the destruction of periodontal tissues. Various methods of regenerative periodontal therapy, including the use of barrier membranes, bone replacement grafts, growth factors and the combination of these procedures have been investigated. The development of biomaterials for tissue engineering has considerably improved the available treatment options above. They fall into two broad classes: ceramics and polymers. The available ceramic-based materials include calcium phosphate (eg, tricalcium phosphate and hydroxyapatite), calcium sulfate and bioactive glass. The bioactive glass bonds to the bone with the formation of a layer of carbonated hydroxyapatite in situ. The natural polymers include modified polysaccharides (eg, chitosan,) and polypeptides (collagen and gelatin). Synthetic polymers [eg, poly(glycolic acid), poly(L-lactic acid)] provide a platform for exhibiting the biomechanical properties of scaffolds in tissue engineering. The materials usually work as osteogenic, osteoconductive and osteoinductive scaffolds. Polymers are more widely used as a barrier material in guided tissue regeneration (GTR). They are shown to exclude epithelial downgrowth and allow periodontal ligament and alveolar bone cells to repopulate the defect. An attempt to overcome the problems related to a collapse of the barrier membrane in GTR or epithelial downgrowth is the use of a combination of barrier membranes and grafting materials. This article reviews various biomaterials including scaffolds and membranes used for periodontal treatment and their impacts on the experimental or clinical management of periodontal defect. PMID:23507891

  6. PLANT MICROBIOME. Salicylic acid modulates colonization of the root microbiome by specific bacterial taxa.

    PubMed

    Lebeis, Sarah L; Paredes, Sur Herrera; Lundberg, Derek S; Breakfield, Natalie; Gehring, Jase; McDonald, Meredith; Malfatti, Stephanie; Glavina del Rio, Tijana; Jones, Corbin D; Tringe, Susannah G; Dangl, Jeffery L

    2015-08-21

    Immune systems distinguish "self" from "nonself" to maintain homeostasis and must differentially gate access to allow colonization by potentially beneficial, nonpathogenic microbes. Plant roots grow within extremely diverse soil microbial communities but assemble a taxonomically limited root-associated microbiome. We grew isogenic Arabidopsis thaliana mutants with altered immune systems in a wild soil and also in recolonization experiments with a synthetic bacterial community. We established that biosynthesis of, and signaling dependent on, the foliar defense phytohormone salicylic acid is required to assemble a normal root microbiome. Salicylic acid modulates colonization of the root by specific bacterial families. Thus, plant immune signaling drives selection from the available microbial communities to sculpt the root microbiome. PMID:26184915

  7. SIMULTANEOUS QUANTIFICATION OF JASMONIC ACID AND SALICYLIC ACID IN PLANTS BY VAPOR PHASE EXTRACTION AND GAS CHROMATOGRAPHY-CHEMICAL IONIZATION-MASS SPECTROMETRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Jasmonic acid and salicylic acid represent important signaling compounds in plant defensive responses against other organisms. Here, we present a new method for the easy, sensitive and reproducible quantification of both compounds by vapor phase extraction and gas chromatography-positive ion chemic...

  8. Nematicidal activity of 5-hydroxymethyl-2-furoic acid against plant-parasitic nematodes.

    PubMed

    Kimura, Yasuo; Tani, Satoko; Hayashi, Asami; Ohtani, Kouhei; Fujioka, Shozo; Kawano, Tsuyoshi; Shimada, Atsumi

    2007-01-01

    A nematicide, 5-hydroxymethyl-2-furoic acid (1), was isolated from cultures of the fungus Aspergillus sp. and its structure was identified by spectroscopic analysis. Compound 1 showed effective nematicidal activities against the pine wood nematode Bursaphelenchus xylophilus and the free-living nematode Caenorhabditis elegans without inhibitory activity against plant growth, but 1 did not show any effective nematicidal activity against Pratylenchus penetrans. PMID:17542490

  9. In situ detection of salicylic acid binding sites in plant tissues.

    PubMed

    Liu, Jing-Wen; Deng, Da-Yi; Yu, Ying; Liu, Fang-Fei; Lin, Bi-Xia; Cao, Yu-Juan; Hu, Xiao-Gang; Wu, Jian-Zhong

    2015-02-01

    The determination of hormone-binding sites in plants is essential in understanding the mechanisms behind hormone function. Salicylic acid (SA) is an important plant hormone that regulates responses to biotic and abiotic stresses. In order to label SA-binding sites in plant tissues, a quantum dots (QDs) probe functionalized with a SA moiety was successfully synthesized by coupling CdSe QDs capped with 3-mercaptopropionic acid (MPA) to 4-amino-2-hydroxybenzoic acid (PAS), using 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide (EDC) as the coupling agent. The probe was then characterized by dynamic light scattering and transmission electron microscopy, as well as UV/vis and fluorescence spectrophotometry. The results confirmed the successful conjugation of PAS to CdSe QDs and revealed that the conjugates maintained the properties of the original QDs, with small core diameters and adequate dispersal in solution. The PAS-CdSe QDs were used to detect SA-binding sites in mung bean and Arabidopsis thaliana seedlings in vitro and in vivo. The PAS-CdSe QDs were effectively transported into plant tissues and specifically bound to SA receptors in vivo. In addition, the effects of the PAS-CdSe QDs on cytosolic Ca(2+) levels in the tips of A. thaliana seedlings were investigated. Both SA and PAS-CdSe QDs had similar effects on the trend in cytosolic-free Ca(2+) concentrations, suggesting that the PAS-CdSe QDs maintained the bioactivity of SA. To summarize, PAS-CdSe QDs have high potential as a fluorescent probe for the in vitro/in vivo labeling and imaging of SA receptors in plants. PMID:24833131

  10. Metabolic engineering of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway into transgenic plants.

    PubMed

    Ruiz-López, Noemi; Sayanova, Olga; Napier, Johnathan A; Haslam, Richard P

    2012-04-01

    Omega-3 (ω-3) very long chain polyunsaturated fatty acids (VLC-PUFAs) such as eicosapentaenoic acid (EPA; 20:5 Δ5,8,11,14,17) and docosahexaenoic acid (DHA; 22:6 Δ4,7,10,13,16,19) have been shown to have significant roles in human health. Currently the primary dietary source of these fatty acids are marine fish; however, the increasing demand for fish and fish oil (in particular the expansion of the aquaculture industry) is placing enormous pressure on diminishing marine stocks. Such overfishing and concerns related to pollution in the marine environment have directed research towards the development of a viable alternative sustainable source of VLC-PUFAs. As a result, the last decade has seen many genes encoding the primary VLC-PUFA biosynthetic activities identified and characterized. This has allowed the reconstitution of the VLC-PUFA biosynthetic pathway in oilseed crops, producing transgenic plants engineered to accumulate ω-3 VLC-PUFAs at levels approaching those found in native marine organisms. Moreover, as a result of these engineering activities, knowledge of the fundamental processes surrounding acyl exchange and lipid remodelling has progressed. The application of new technologies, for example lipidomics and next-generation sequencing, is providing a better understanding of seed oil biosynthesis and opportunities for increasing the production of unusual fatty acids. Certainly, it is now possible to modify the composition of plant oils successfully, and, in this review, the most recent developments in this field and the challenges of producing VLC-PUFAs in the seed oil of higher plants will be described. PMID:22291131

  11. Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides

    PubMed Central

    Gagne, Steve J.; Stout, Jake M.; Liu, Enwu; Boubakir, Zakia; Clark, Shawn M.; Page, Jonathan E.

    2012-01-01

    Δ9-Tetrahydrocannabinol (THC) and other cannabinoids are responsible for the psychoactive and medicinal properties of Cannabis sativa L. (marijuana). The first intermediate in the cannabinoid biosynthetic pathway is proposed to be olivetolic acid (OA), an alkylresorcinolic acid that forms the polyketide nucleus of the cannabinoids. OA has been postulated to be synthesized by a type III polyketide synthase (PKS) enzyme, but so far type III PKSs from cannabis have been shown to produce catalytic byproducts instead of OA. We analyzed the transcriptome of glandular trichomes from female cannabis flowers, which are the primary site of cannabinoid biosynthesis, and searched for polyketide cyclase-like enzymes that could assist in OA cyclization. Here, we show that a type III PKS (tetraketide synthase) from cannabis trichomes requires the presence of a polyketide cyclase enzyme, olivetolic acid cyclase (OAC), which catalyzes a C2–C7 intramolecular aldol condensation with carboxylate retention to form OA. OAC is a dimeric α+β barrel (DABB) protein that is structurally similar to polyketide cyclases from Streptomyces species. OAC transcript is present at high levels in glandular trichomes, an expression profile that parallels other cannabinoid pathway enzymes. Our identification of OAC both clarifies the cannabinoid pathway and demonstrates unexpected evolutionary parallels between polyketide biosynthesis in plants and bacteria. In addition, the widespread occurrence of DABB proteins in plants suggests that polyketide cyclases may play an overlooked role in generating plant chemical diversity. PMID:22802619

  12. Membrane reactors for continuous coenzyme regeneration

    NASA Astrophysics Data System (ADS)

    Wandrey, C.; Wichmann, R.

    1982-12-01

    The importance of continuous coenzyme regeneration is discussed with respect to chemical reaction engineering. The benefit of coenzymes covalently bound to water soluble polymers is especially stressed. The performance of membrane reactors for coenzyme regeneration is discussed in comparison with other reactor concepts. The coenzyme dependent production of L-amino acids from the corresponding alpha-keto acids is used to illustrate how precise turnover numbers as a function of enzyme/coenzyme ratio, initial substrate concentration, and conversion are obtained. Thus, it becomes possible to develop a concept for optimal operating points with respect to enzyme, coenzyme, and substrate costs per unit weight of product.

  13. Combining hexanoic acid plant priming with Bacillus thuringiensis insecticidal activity against Colorado potato beetle.

    PubMed

    García-Robles, Inmaculada; Ochoa-Campuzano, Camila; Fernández-Crespo, Emma; Camañes, Gemma; Martínez-Ramírez, Amparo C; González-Bosch, Carmen; García-Agustín, Pilar; Rausell, Carolina; Real, María Dolores

    2013-01-01

    Interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in Colorado potato beetle (CPB) pest management. Feeding tests with CPB larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to Bacillus thuringiensis Cry3Aa toxin as a function of the host plant. An inverse correlation with toxicity was observed in Cry3Aa proteolytic patterns generated by CPB midgut brush-border membrane vesicles (BBMV) from Solanaceae-fed larvae, being the toxin most extensively proteolyzed on potato, followed by eggplant and tomato. We found that CPB cysteine proteases intestains may interact with Cry3Aa toxin and, in CPB BBMV from larvae fed all three Solanaceae, the toxin was able to compete for the hydrolysis of a papain substrate. In response to treatment with the JA-dependent plant inducer Hexanoic acid (Hx), we showed that eggplant reduced OPDA basal levels and both, potato and eggplant induced JA-Ile. CPB larvae feeding on Hx-induced plants exhibited enhanced Cry3Aa toxicity, which correlated with altered papain activity. Results indicated host-mediated effects on B. thuringiensis efficacy against CPB that can be enhanced in combination with Hx plant induction. PMID:23743826

  14. Combining Hexanoic Acid Plant Priming with Bacillus thuringiensis Insecticidal Activity against Colorado Potato Beetle

    PubMed Central

    García-Robles, Inmaculada; Ochoa-Campuzano, Camila; Fernández-Crespo, Emma; Camañes, Gemma; Martínez-Ramírez, Amparo C.; González-Bosch, Carmen; García-Agustín, Pilar; Rausell, Carolina; Real, María Dolores

    2013-01-01

    Interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in Colorado potato beetle (CPB) pest management. Feeding tests with CPB larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to Bacillus thuringiensis Cry3Aa toxin as a function of the host plant. An inverse correlation with toxicity was observed in Cry3Aa proteolytic patterns generated by CPB midgut brush-border membrane vesicles (BBMV) from Solanaceae-fed larvae, being the toxin most extensively proteolyzed on potato, followed by eggplant and tomato. We found that CPB cysteine proteases intestains may interact with Cry3Aa toxin and, in CPB BBMV from larvae fed all three Solanaceae, the toxin was able to compete for the hydrolysis of a papain substrate. In response to treatment with the JA-dependent plant inducer Hexanoic acid (Hx), we showed that eggplant reduced OPDA basal levels and both, potato and eggplant induced JA-Ile. CPB larvae feeding on Hx-induced plants exhibited enhanced Cry3Aa toxicity, which correlated with altered papain activity. Results indicated host-mediated effects on B. thuringiensis efficacy against CPB that can be enhanced in combination with Hx plant induction. PMID:23743826

  15. Competing mechanisms for perfluoroalkyl acid accumulation in plants revealed using an Arabidopsis model system.

    PubMed

    Müller, Claudia E; LeFevre, Gregory H; Timofte, Anca E; Hussain, Fatima A; Sattely, Elizabeth S; Luthy, Richard G

    2016-05-01

    Perfluoroalkyl acids (PFAAs) bioaccumulate in plants, presenting a human exposure route if present in irrigation water. Curiously, accumulation of PFAAs in plant tissues is greatest for both the short-chain and long-chain PFAAs, generating a U-shaped relationship with chain length. In the present study, the authors decouple competing mechanisms of PFAA accumulation using a hydroponic model plant system (Arabidopsis thaliana) exposed to a suite of 10 PFAAs to determine uptake, depuration, and translocation kinetics. Rapid saturation of root concentrations occurred for all PFAAs except perfluorobutanoate, the least-sorptive (shortest-chain) PFAA. Shoot concentrations increased continuously, indicating that PFAAs are efficiently transported and accumulate in shoots. Tissue concentrations of PFAAs during depuration rapidly declined in roots but remained constant in shoots, demonstrating irreversibility of the translocation process. Root and shoot concentration factors followed the U-shaped trend with perfluoroalkyl chain length; however, when normalized to dead-tissue sorption, this relationship linearized. The authors therefore introduce a novel term, the "sorption normalized concentration factor," to describe PFAA accumulation in plants; because of their hydrophobicity, sorption is the determining factor for long-chain PFAAs, whereas the shortest-chain PFAAs are most effectively transported in the plant. The present study provides a mechanistic explanation for previously unexplained PFAA accumulation trends in plants and suggests that shorter-chained PFAAs may bioaccumulate more readily in edible portions. Environ Toxicol Chem 2016;35:1138-1147. © 2015 SETAC. PMID:26383989

  16. Desulfurization sorbent regeneration

    DOEpatents

    Jalan, V.M.; Frost, D.G.

    1982-07-07

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

  17. Separation of phenolic acids from natural plant extracts using molecularly imprinted anion-exchange polymer confined ionic liquids.

    PubMed

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2012-04-01

    Polymer-confined ionic liquids were used for the separation of phenolic acids from natural plant extract by utilizing an anion-exchange mechanism. They were synthesized using molecular imprinting technique to reduce non-directional ion-ion interactions during anion-exchange and other interactions with interference substances that could decrease selectivity. A suitable sorbent for phenolic acid separation could be identified based on the adsorption behaviors of phenolic acids on different polymer-confined ionic liquids. Thus, the developed ionic liquid-based molecularly imprinted anion-exchange polymer (IMAP) achieved high recovery rates by solid-phase extraction of phenolic acids from Salicornia herbacea L. extract: 90.1% for protocatechuic acid, 95.5% for ferulic acid and 96.6% for caffeic acid. Moreover, the phenolic acids were separable from each other by repeated solid phase extraction cycles. The proposed method could be used to separate other phenolic acids or organic acids from complex samples. PMID:21903215

  18. Assessment and comparison of 100-MW coal gasification phosphoric acid fuel cell power plants

    NASA Technical Reports Server (NTRS)

    Lu, Cheng-Yi

    1988-01-01

    One of the advantages of fuel cell (FC) power plants is fuel versatility. With changes only in the fuel processor, the power plant will be able to accept a variety of fuels. This study was performed to design process diagrams, evaluate performance, and to estimate cost of 100 MW coal gasifier (CG)/phosphoric acid fuel cell (PAFC) power plant systems utilizing coal, which is the largest single potential source of alternate hydrocarbon liquids and gases in the United States, as the fuel. Results of this study will identify the most promising integrated CG/PAFC design and its near-optimal operating conditions. The comparison is based on the performance and cost of electricity which is calculated under consistent financial assumptions.

  19. Plant perception of β-aminobutyric acid is mediated by an aspartyl-tRNA synthetase

    PubMed Central

    Luna, Estrella; van Hulten, Marieke; Zhang, Yuhua; Berkowitz, Oliver; López, Ana; Pétriacq, Pierre; Sellwood, Matthew A.; Chen, Beining; Burrell, Mike; van de Meene, Allison; Pieterse, Corné M.J.; Flors, Victor; Ton, Jurriaan

    2014-01-01

    Specific chemicals can prime the plant immune system for augmented defence. β-aminobutyric acid (BABA) is a priming agent that provides broad-spectrum disease protection. However, BABA also suppresses plant growth when applied in high doses, which has hampered its application as a crop defence activator. Here we describe a mutant of Arabidopsis thaliana that is impaired in BABA-induced disease immunity (ibi1) but hypersensitive to BABA-induced growth repression. IBI encodes an aspartyl-tRNA synthetase. Enantiomer-specific binding of R-BABA to IBI1 primed the protein for non-canonical defence signalling in the cytoplasm after pathogen attack. This priming was associated with aspartic acid accumulation and tRNA-induced phosphorylation of translation initiation factor eIF2α. However, mutation of eIF2α-phosphorylating GCN2 kinase did not affect BABA-induced immunity, but relieved BABA-induced growth repression. Hence, BABA-activated IBI1 controls plant immunity and growth via separate pathways. Our results open new opportunities to separate broad-spectrum disease resistance from the associated costs on plant growth. PMID:24776930

  20. Plant perception of β-aminobutyric acid is mediated by an aspartyl-tRNA synthetase.

    PubMed

    Luna, Estrella; van Hulten, Marieke; Zhang, Yuhua; Berkowitz, Oliver; López, Ana; Pétriacq, Pierre; Sellwood, Matthew A; Chen, Beining; Burrell, Mike; van de Meene, Allison; Pieterse, Corné M J; Flors, Victor; Ton, Jurriaan

    2014-06-01

    Specific chemicals can prime the plant immune system for augmented defense. β-aminobutyric acid (BABA) is a priming agent that provides broad-spectrum disease protection. However, BABA also suppresses plant growth when applied in high doses, which has hampered its application as a crop defense activator. Here we describe a mutant of Arabidopsis thaliana that is impaired in BABA-induced disease immunity (ibi1) but is hypersensitive to BABA-induced growth repression. IBI1 encodes an aspartyl-tRNA synthetase. Enantiomer-specific binding of the R enantiomer of BABA to IBI1 primed the protein for noncanonical defense signaling in the cytoplasm after pathogen attack. This priming was associated with aspartic acid accumulation and tRNA-induced phosphorylation of translation initiation factor eIF2α. However, mutation of eIF2α-phosphorylating GCN2 kinase did not affect BABA-induced immunity but relieved BABA-induced growth repression. Hence, BABA-activated IBI1 controls plant immunity and growth via separate pathways. Our results open new opportunities to separate broad-spectrum disease resistance from the associated costs on plant growth. PMID:24776930

  1. HPLC-Profiles of Tocopherols, Sugars, and Organic Acids in Three Medicinal Plants Consumed as Infusions.

    PubMed

    Roriz, Custódio Lobo; Barros, Lillian; Carvalho, Ana Maria; Ferreira, Isabel C F R

    2014-01-01

    Pterospartum tridentatum (L.) Willk, Gomphrena globosa L., and Cymbopogon citratus (DC.) Stapf are medicinal plants that require a more detailed chemical characterization, given the importance of their consumption as infusions. Therefore, the individual profiles in tocopherols, free sugars, and organic acids were obtained by high performance liquid chromatography (HPLC) coupled to different detectors (fluorescence, refraction index, and photodiode array, resp.). C. citratus revealed the highest content of α-, and total tocopherols, glucose, sucrose, succinic, and ascorbic acids. P. tridentatum presented the highest fructose and total sugars content. Otherwise, G. globosa showed the highest organic acids concentration. As far as we know, this is the first study reporting the mentioned chemical compounds in G. globosa and C. citratus. PMID:26904623

  2. Fatty acids and sterols composition, and antioxidant activity of oils extracted from plant seeds.

    PubMed

    Kozłowska, Mariola; Gruczyńska, Eliza; Ścibisz, Iwona; Rudzińska, Magdalena

    2016-12-15

    This study determined and compared the contents of bioactive components in plant seed oils extracted with n-hexane (Soxhlet method) and chloroform/methanol (Folch method) from coriander, caraway, anise, nutmeg and white mustard seeds. Oleic acid dominated among unsaturated fatty acids in nutmeg and anise seed oils while petroselinic acid was present in coriander and caraway oils. Concerning sterols, β-sitosterol was the main component in seed oils extracted with both methods. The content of total phenolics in nutmeg, white mustard and coriander seed oils extracted with chloroform/methanol was higher than in their counterparts prepared with n-hexane. The seed oil samples extracted according to the Folch method exhibited a higher ability to scavenge DPPH radicals compared to the oil samples prepared with the Soxhlet method. DPPH values of the methanolic extracts derived from oils produced with the Folch method were also higher than in the oils extracted with n-hexane. PMID:27451203

  3. HPLC-Profiles of Tocopherols, Sugars, and Organic Acids in Three Medicinal Plants Consumed as Infusions

    PubMed Central

    Roriz, Custódio Lobo; Barros, Lillian; Carvalho, Ana Maria; Ferreira, Isabel C. F. R.

    2014-01-01

    Pterospartum tridentatum (L.) Willk, Gomphrena globosa L., and Cymbopogon citratus (DC.) Stapf are medicinal plants that require a more detailed chemical characterization, given the importance of their consumption as infusions. Therefore, the individual profiles in tocopherols, free sugars, and organic acids were obtained by high performance liquid chromatography (HPLC) coupled to different detectors (fluorescence, refraction index, and photodiode array, resp.). C. citratus revealed the highest content of α-, and total tocopherols, glucose, sucrose, succinic, and ascorbic acids. P. tridentatum presented the highest fructose and total sugars content. Otherwise, G. globosa showed the highest organic acids concentration. As far as we know, this is the first study reporting the mentioned chemical compounds in G. globosa and C. citratus. PMID:26904623

  4. Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium Azospirillum spp.

    NASA Astrophysics Data System (ADS)

    Rodriguez, Hilda; Gonzalez, Tania; Goire, Isabel; Bashan, Yoav

    2004-11-01

    In vitro gluconic acid formation and phosphate solubilization from sparingly soluble phosphorus sources by two strains of the plant growth-promoting bacteria A. brasilense (Cd and 8-I) and one strain of A. lipoferum JA4 were studied. Strains of A. brasilense were capable of producing gluconic acid when grown in sparingly soluble calcium phosphate medium when their usual fructose carbon source is amended with glucose. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. To a greater extent, gluconic acid production and pH reduction were observed for A. lipoferum JA4. For the three strains, clearing halos were detected on solid medium plates with calcium phosphate. This is the first report of in vitro gluconic acid production and direct phosphate solubilization by A. brasilense and the first report of P solubilization by A. lipoferum. This adds to the very broad spectrum of plant growth-promoting abilities of this genus.

  5. Photosynthesis and water relations in tomato plants cultivated long-term in media containing (+)-usnic acid.

    PubMed

    Latkowska, E; Lechowski, Z; Bialczyk, J; Pilarski, J

    2006-09-01

    The influence of (+)-usnic acid on rates of gas exchange (photosynthesis, respiration, and transpiration) in long-term cultivation of tomato plants was studied. The effect was dose-dependent. Plants grown in media containing the maximum concentration of (+)-usnic acid (30 muM) had photosynthetic and respiration rates reduced by 41% and 80%, respectively. The effect on photosynthesis rate may be the result of a multidirectional effect at various stages of this process, which at the highest usnic acid concentration underwent reduction: content of chlorophylls by 30%, carotenoids by 35%, and Hill reaction activity by 75%. Usnic acid also raises the susceptibility of chlorophyll to photodegradation. Under some conditions, transpiration was reduced by 2.1-fold in light and 3.7-fold in dark. This result was correlated with (1) an increase in the diffusive resistance of the stomata (3.1-fold in upper and 1.5-fold in lower surface of leaf), (2) a reduction of stomata density (by 60% on upper and 40% on lower surface), and (3) a 12.3-fold decrease in root hydraulic conductance. PMID:16902819

  6. Adventitious bud regeneration from leaf expiants of the shrubby ornamental honeysuckle, Lonicera nitida Wils. cv. 'Maigrün': effects of thidiazuron and 2,3,5-triiodobenzoic acid.

    PubMed

    Cambecèdes, J; Duron, M; Decourtye, L

    1991-11-01

    Different combinations of auxins and cytokinins were employed to assess the regeneration capacity from in vitro leaf explants of Lonicera nitida Wils. cv 'Maïgrün'. A high frequency of rhizogenesis was noticed, with 2.3 μM thidiazuron plus 2.9 μM indole-3-acetic acid as the only hormonal combination to support caulogenic responses. Increasing thidiazuron concentration and/or suppressing auxin did not improve caulogenesis. Combining thidiazuron with 2,3,5-triiodobenzoic acid produced a dramatic increase in the percentage of caulogenic explants. A maximum of 74% of adventitious bud forming explants was obtained with 2.3 μM thidiazuron plus 20 μM 2,3,5-triiodobenzoic acid. Buds were often in a rosette form and were vitreous, so that shoot elongation was difficult to obtain. The effect of the duration of the 2,3,5-triiodobenzoic acid treatment on shoot elongation was investigated. PMID:24221854

  7. Regeneration Heat Exchange

    SciTech Connect

    J. Lin

    2003-07-30

    The original project goals were to establish the viability of the proposed gas turbine regenerator concept by performing the following tasks: (1) Perform detailed design of a working model of the regenerator concept. (2) Construct a ''bench-top'' model of the regenerator concept based upon the detail design. (3) Test the bench-top model and gather data to support the concept's viability. The project funding was used to acquire the tools and material to perform the aforementioned tasks.

  8. Accumulation of seleno-amino acids in legume and grass plant species grown in selenium-laden soils

    SciTech Connect

    Wu, L.; Guo, X.; Banuelos, G.S.

    1997-03-01

    Seleno-amino acid accumulation was studied for two legume and two grass species grown in Selenium (Se)-laden soils. An antagonistic relationship was found between the tissue Se-amino acid concentration and the corresponding sulfur-amino acid concentration. This relationship demonstrates a competitive interaction between Se and sulfate at the amino acid synthesis level. The nonsulfur-containing amino acids were not substantially affected by the increase of tissue Se concentration. Sour clover (Melilotus indica L.) was able to accumulate much greater tissue Se concentration than the other three species. Tissue methionine concentration of sour clover, rabbitfoot grass (Polypogon monspeliensis L.), and tall fescue (Festuca arundinacea Schreb.) was not significantly affected by the increase of tissue selenomethionine concentration, but a highly significant negative correlation was found in alfalfa (Medicago sativa L.). This discrepancy suggests that a less antagonistic effect on sulfur-amino acids under the increase of Se-amino acid analogues in the tissue might be able to minimize Se toxicity to the plant. Both Se-methylselenocysteine (nonprotein amino acid) and selenomethionine (protein amino acid) accumulated in the plants when grown in Se-laden soils. Possible effects of these Se-amino acids accumulated by plants on animal health should be tested before the plants are used for forage supplementation.

  9. Air and blood lead levels in lead acid battery recycling and manufacturing plants in Kenya.

    PubMed

    Were, Faridah H; Kamau, Geoffrey N; Shiundu, Paul M; Wafula, Godfrey A; Moturi, Charles M

    2012-01-01

    The concentration of airborne and blood lead (Pb) was assessed in a Pb acid battery recycling plant and in a Pb acid battery manufacturing plant in Kenya. In the recycling plant, full-shift area samples taken across 5 days in several production sections showed a mean value ± standard deviation (SD) of 427 ± 124 μg/m(3), while area samples in the office area had a mean ± SD of 59.2 ± 22.7 μg/m(3). In the battery manufacturing plant, full-shift area samples taken across 5 days in several production areas showed a mean value ± SD of 349 ± 107 μg/m(3), while area samples in the office area had a mean ± SD of 55.2 ± 33.2 μg/m(3). All these mean values exceed the U.S. Occupational Safety and Health Administration's permissible exposure limit of 50 μg/m(3) as an 8-hr time-weighted average. In the battery recycling plant, production workers had a mean blood Pb level ± SD of 62.2 ± 12.7 μg/dL, and office workers had a mean blood Pb level ± SD of 43.4 ± 6.6 μg/dL. In the battery manufacturing plant, production workers had a mean blood Pb level ± SD of 59.5 ± 10.1 μg/dL, and office workers had a mean blood Pb level ± SD of 41.6 ± 7.4 μg/dL. All the measured blood Pb levels exceeded 30 μg/dL, which is the maximum blood Pb level recommended by the ACGIH(®). Observations made in these facilities revealed numerous sources of Pb exposure due to inadequacies in engineering controls, work practices, respirator use, and personal hygiene. PMID:22512792

  10. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  11. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  12. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  13. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  14. 40 CFR 174.507 - Nucleic acids that are part of a plant-incorporated protectant; exemption from the requirement of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Nucleic acids that are part of a plant... PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.507 Nucleic acids that are part... nucleic acids that are part of a plant-incorporated protectant are exempt from the requirement of...

  15. Effect of 1-naphthaleneacetic acid on organic acid exudation by the roots of white lupin plants grown under phosphorus-deficient conditions.

    PubMed

    Gómez, Diego A; Carpena, Ramón O

    2014-09-15

    The effect of NAA (1-naphthaleneacetic acid) on organic acid exudation in white lupin plants grown under phosphorus deficiency was investigated. Plants were sampled periodically for collecting of organic acids (citrate, malate, succinate), and also were used to study the effect on proton extrusion and release of Na(+), K(+), Ca(2+) and Mg(2+). The tissues were later processed to quantify the organic acids in tissues, the phosphorus content and the effects on plant biomass. The exogenous addition of NAA led to an increase in organic acid exudation, but this response was not proportional to the concentration of the dose applied, noticing the largest increments with NAA 10(-8)M. In contrast the increase in root weight was proportional to the dose applied, which shows that with higher doses the roots produced are not of proteoid type. Proton extrusion and the release of cations were related to the NAA dose, the first was proportional to the dose applied and the second inversely proportional. Regarding the analysis of tissues, the results of citrate and phosphorus content in shoots show that the overall status of these parts are the main responsible of the organic acids exuded. NAA served as an enhancer of the organic acid exudation that occurs under phosphorus deficient conditions, with a response that depends on the dose applied, not only in its magnitude, but also in the mechanism of action of the plant hormone. PMID:25046756

  16. MHD seed recovery and regeneration

    NASA Astrophysics Data System (ADS)

    1988-10-01

    The TRW Econoseed MHD Seed Regeneration Process is based on the reaction of calcium formate with potassium sulfate spent seed from an MHD electric power generation plant. The process was tested at bench scale, design a proof of concept (POC) test plant, plan and cost a Phase 2 project for a POC plant evaluation and prepare a conceptual design of a 300 MW (t) commercial plant. The results of the project are as follows: (1) each of the unit operations is demonstrated, and (2) the data are incorporated into a POC plant design and project cost, as well as a 300 MW (t) commercial retrofit plant design and cost estimate. Specific results are as follows: (1) calcium formate can be produced at 100 percent yield in a total retention time of less than 5 minutes, (2) utilizing the calcium formate, spent seed can quantitatively be converted to potassium formate, potassium carbonate or mixtures of these with potassium sulfate as per the commercial design without measurable loss of potassium to insolubles at a total retention time under 20 minutes and ambient pressure, (3) the solid rejects form the process meet RCRA EP Toxicity requirements for safe disposal, and (4) filtration and evaporation data, as well as reaction data cited above, show that the Econoseed technology is ready for scale up to POC plant scale. Economics forecast studies show that the total cost per unit of potassium for seed regeneration by the Econoseed Process is in the range of $0.23 to $0.27/lb, a cost which is less than half the potassium cost of $0.63/lb for purchasing new potassium carbonate.

  17. Plant and Soil Emissions of Amines and Amino Acids: A Source of Secondary Aerosol Precursors

    NASA Astrophysics Data System (ADS)

    Jackson, M. L.; Doskey, P. V.; Pypker, T. G.

    2011-12-01

    Ammonia (NH3) is the most abundant alkaline gas in the atmosphere and forms secondary aerosol by neutralizing sulfuric and nitric acids that are released during combustion of fossil fuels. Ammonia is primarily emitted by cropping and livestock operations. However, C2 and C3 amines (pKb 3.3-3.4), which are stronger bases than NH3 (pKb 4.7) have been observed in nuclei mode aerosol that is the precursor to secondary aerosol. Mixtures of amines and amino acids have been identified in diverse environments in aerosol, fog water, cloud water, the soluble fraction of precipitation, and in dew. Glycine (pKb 4.2), serine (pKb 4.8) and alanine (pKb 3.7 and 4.1 for the D and L forms, respectively) are typically the most abundant species. The only reported values of gas-phase glycine, serine and alanine were in marine air and ranged from 6-14 pptv. The origin of atmospheric amines and amino acids has not been fully identified, although sources are likely similar to NH3. Nitrate assimilation in plants forms glycine, serine, and L-alanine, while D-alanine is present in bacterial cell walls. Glycine is converted to serine during C3 plant photorespiration, producing CO2 and NH3. Bacteria metabolize glycine and alanine to methylamine and ethylamine via decarboxylation. Likely sources of amino acids are plants and bacteria, thus concentrations near continental sources are likely greater than those measured in marine air. The overall goal of the research is to examine seasonal variations and relationships between the exchange of CO2, NH3, amines, and amino acids with a corn/soybean rotation in the Midwest Corn Belt. The study presents gaseous profiles of organic amine compounds from various species of vegetation using a mist chamber trapping technique and analysis of the derivatized species by high pressure liquid chromatography with fluorescence detection. Amino acid and amine profiles were obtained for red oak (Quercus rubra), sugar maple (Acer saccharinum), white pine (Pinus

  18. Biochemical Evaluation of the Decarboxylation and Decarboxylation-Deamination Activities of Plant Aromatic Amino Acid Decarboxylases*

    PubMed Central

    Torrens-Spence, Michael P.; Liu, Pingyang; Ding, Haizhen; Harich, Kim; Gillaspy, Glenda; Li, Jianyong

    2013-01-01

    Plant aromatic amino acid decarboxylase (AAAD) enzymes are capable of catalyzing either decarboxylation or decarboxylation-deamination on various combinations of aromatic amino acid substrates. These two different activities result in the production of arylalkylamines and the formation of aromatic acetaldehydes, respectively. Variations in product formation enable individual enzymes to play different physiological functions. Despite these catalytic variations, arylalkylamine and aldehyde synthesizing AAADs are indistinguishable without protein expression and characterization. In this study, extensive biochemical characterization of plant AAADs was performed to identify residues responsible for differentiating decarboxylation AAADs from aldehyde synthase AAADs. Results demonstrated that a tyrosine residue located on a catalytic loop proximal to the active site of plant AAADs is primarily responsible for dictating typical decarboxylase activity, whereas a phenylalanine at the same position is primarily liable for aldehyde synthase activity. Mutagenesis of the active site phenylalanine to tyrosine in Arabidopsis thaliana and Petroselinum crispum aromatic acetaldehyde synthases primarily converts the enzymes activity from decarboxylation-deamination to decarboxylation. The mutation of the active site tyrosine to phenylalanine in the Catharanthus roseus and Papaver somniferum aromatic amino acid decarboxylases changes the enzymes decarboxylation activity to a primarily decarboxylation-deamination activity. Generation of these mutant enzymes enables the production of unusual AAAD enzyme products including indole-3-acetaldehyde, 4-hydroxyphenylacetaldehyde, and phenylethylamine. Our data indicates that the tyrosine and phenylalanine in the catalytic loop region could serve as a signature residue to reliably distinguish plant arylalkylamine and aldehyde synthesizing AAADs. Additionally, the resulting data enables further insights into the mechanistic roles of active site

  19. Interactions between uptake of amino acids and inorganic nitrogen in wheat plants

    NASA Astrophysics Data System (ADS)

    Gioseffi, E.; de Neergaard, A.; Schjoerring, J. K.

    2011-11-01

    Soil-borne amino acids may constitute a nitrogen (N) source for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO3-) and (NH4+) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake. Amino acids were enriched with double-labelled 15N and 13C, while NO3- and NH4+ acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO3- and NH4+ did not differ from each other and were about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50 % of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO3- did not affect glycine uptake, while the presence of glycine down-regulated NO3- uptake. The ratio between 13C and 15N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic nitrogen.

  20. Interactions between uptake of amino acids and inorganic nitrogen in wheat plants

    NASA Astrophysics Data System (ADS)

    Gioseffi, E.; de Neergaard, A.; Schjoerring, J. K.

    2012-04-01

    Soil-borne amino acids may constitute a source of nitrogen (N) for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO3-) and ammonium (NH4+) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake, thereby resulting in similar total N uptake rates. Amino acids were enriched with double-labelled 15N and 13C, while NO3- and NH4+ acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO3- and NH4+ did not differ from each other and were generally about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50% of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO3- did not affect glycine uptake, while the presence of glycine down-regulated NO3- uptake. The ratio between 13C and 15N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic N.