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Sample records for mesophyll chloroplast crude

  1. Consequences of C4 differentiation for chloroplast membrane proteomes in maize mesophyll and bundle sheath cells.

    Majeran, Wojciech; Zybailov, Boris; Ytterberg, A Jimmy; Dunsmore, Jason; Sun, Qi; van Wijk, Klaas J

    2008-09-01

    Chloroplasts of maize leaves differentiate into specific bundle sheath (BS) and mesophyll (M) types to accommodate C(4) photosynthesis. Chloroplasts contain thylakoid and envelope membranes that contain the photosynthetic machineries and transporters but also proteins involved in e.g. protein homeostasis. These chloroplast membranes must be specialized within each cell type to accommodate C(4) photosynthesis and regulate metabolic fluxes and activities. This quantitative study determined the differentiated state of BS and M chloroplast thylakoid and envelope membrane proteomes and their oligomeric states using innovative gel-based and mass spectrometry-based protein quantifications. This included native gels, iTRAQ, and label-free quantification using an LTQ-Orbitrap. Subunits of Photosystems I and II, the cytochrome b(6)f, and ATP synthase complexes showed average BS/M accumulation ratios of 1.6, 0.45, 1.0, and 1.33, respectively, whereas ratios for the light-harvesting complex I and II families were 1.72 and 0.68, respectively. A 1000-kDa BS-specific NAD(P)H dehydrogenase complex with associated proteins of unknown function containing more than 15 proteins was observed; we speculate that this novel complex possibly functions in inorganic carbon concentration when carboxylation rates by ribulose-bisphosphate carboxylase/oxygenase are lower than decarboxylation rates by malic enzyme. Differential accumulation of thylakoid proteases (Egy and DegP), state transition kinases (STN7,8), and Photosystem I and II assembly factors was observed, suggesting that cell-specific photosynthetic electron transport depends on post-translational regulatory mechanisms. BS/M ratios for inner envelope transporters phosphoenolpyruvate/P(i) translocator, Dit1, Dit2, and Mex1 were determined and reflect metabolic fluxes in carbon metabolism. A wide variety of hundreds of other proteins showed differential BS/M accumulation. Mass spectral information and functional annotations are

  2. Comparative proteomics of chloroplasts envelopes from bundle sheath and mesophyll chloroplasts reveals novel membrane proteins with a possible role in C4-related metabolite fluxes and development.

    Kalpana eManandhar-Shrestha

    2013-03-01

    Full Text Available As the world population grows, our need for food increases drastically. Limited amounts of arable land lead to a competition between food and fuel crops, while changes in the global climate may impact future crop yields. Thus, a second green revolution will need a better understanding of the processes essential for plant growth and development. One approach toward the solution of this problem is to better understand regulatory and transport processes in C4 plants. C4 plants display an up to 10-fold higher apparent CO2 assimilation and higher yields while maintaining high water use efficiency. This requires differential regulation of mesophyll (M and bundle sheath (BS chloroplast development as well as higher metabolic fluxes of photosynthetic intermediates between cells and across chloroplast envelopes. While previous analyses of overall chloroplast membranes have yielded significant insight, our comparative proteomics approach using enriched BS and M chloroplast envelopes of Zea mays allowed us to identify 37 proteins of unknown function that have not been seen in these earlier studies. We identified 280 proteins, 84% of which are known/predicted to be present in chloroplasts (cp. 74% have a known or predicted membrane association. 21 membrane proteins were 2-15 times more abundant in BS cells, while 36 proteins were more abundant in M cp envelopes. These proteins could represent additional candidates of proteins essential for development or metabolite transport processes in C4 plants. RT-PCR confirmed differential expression of thirteen candidate genes. Cp association was confirmed using GFP labeling. Genes for a PIC-like protein and an ER-AP-like protein show an early transient increase in gene expression during the transition to light. In addition, PIC gene expression is increased in the immature part of the leaf and was lower in the fully developed parts of the leaf, suggesting a need for/incorporation of the protein during chloroplast

  3. Intracellular position of mitochondria and chloroplasts in bundle sheath and mesophyll cells of C3 grasses in relation to photorespiratory CO2 loss

    Yuto Hatakeyama

    2016-10-01

    Full Text Available In C3 plants, photosynthetic efficiency is reduced by photorespiration. A part of CO2 fixed during photosynthesis in chloroplasts is lost from mitochondria during photorespiration by decarboxylation of glycine by glycine decarboxylase (GDC. Thus, the intracellular position of mitochondria in photosynthetic cells is critical to the rate of photorespiratory CO2 loss. We investigated the intracellular position of mitochondria in parenchyma sheath (PS and mesophyll cells of 10 C3 grasses from 3 subfamilies (Ehrhartoideae, Panicoideae, and Pooideae by immunostaining for GDC and light and electron microscopic observation. Immunostaining suggested that many mitochondria were located in the inner half of PS cells and on the vacuole side of chloroplasts in mesophyll cells. Organelle quantification showed that 62–75% of PS mitochondria were located in the inner half of cells, and 62–78% of PS chloroplasts were in the outer half. In mesophyll cells, 61–92% of mitochondria were positioned on the vacuole side of chloroplasts and stromules. In PS cells, such location would reduce the loss of photorespiratory CO2 by lengthening the path of CO2 diffusion and allow more efficient fixation of CO2 from intercellular spaces. In mesophyll cells, it would facilitate scavenging by chloroplasts of photorespiratory CO2 released from mitochondria. Our data suggest that the PS cells of C3 grasses have already acquired an initial structure leading to proto-Kranz and further C3–C4 intermediate anatomy. We also found that in the Pooideae, organelle positioning in PS cells on the phloem side resembles that in mesophyll cells.

  4. [Effects of light intensities after anthesis on the photosynthetic characteristics and chloroplast ultrastructure in mesophyll cell of summer maize (Zea mays L. )].

    Gao, Jia; Cui, Hai Yan; Shi, Jian Guo; Dong, Shu Ting; Liu, Peng; Zhao, Bin; Zhang, Ji Wang

    2018-03-01

    We examined the changes of photosynthetic characteristics and chloroplast ultrastructure in mesophyll cell of summer maize in response to different light intensities in the field, with the summer maize hybrid Denghai 605 as experimental material. Two treatments of both shading (S) and increasing light (L) from flowering to physiological maturity stage were designed, with the ambient sunlight treatment as control (CK). Under shading treatment, poorly developed thylakoid structure, blurry lamellar structure, loose granum, large gap between slices and warping granum were the major characteristics in chloroplast. Meanwhile, photosynthetic rate (P n ), transpiration rate, stomatal conductance, chlorophyll content, and actual photo-chemical efficiency (Φ PSII ) decreased, whereas the maximal photochemical efficiency and non-photochemical quenching increased, which resulted in decreases in grain yield under shading treatment. However, a better development was observed in chloroplasts for L treatment, with the number of grana and lamellae increased and lamellae arranged compactly. In addition, P n and Φ PSII increased under L treatment, which increased grain yield. The chloroplast arrangement dispersed in mesophyll cells and chloroplast ultrastructure was destroyed after shading, and then chlorophyll synthesis per unit leaf area and photosynthetic capacity decreased. In contrast, the number of grana and lamellae increased and lamellae arranged compactly after increasing light, which are beneficial for corn yield.

  5. Identification of the TaBTF3 gene in wheat (Triticum aestivum L.) and the effect of its silencing on wheat chloroplast, mitochondria and mesophyll cell development.

    Ma, Hong-Zhen; Liu, Guo-Qin; Li, Cheng-Wei; Kang, Guo-Zhang; Guo, Tian-Cai

    2012-10-05

    The full-length cDNA (882bp) and DNA (1742bp) sequences encoding a basic transcription factor 3, designated as TaBTF3, were first isolated from common wheat (Triticum aestivum L.). Subcellular localization studies revealed that the TaBTF3 protein was mainly located in the cytoplasm and nucleus. In TaBTF3-silenced transgenic wheat seedlings obtained using the Virus-induced gene silencing (VIGS) method, the chlorophyll pigment content was markedly reduced. However, the malonaldehyde (MDA) and H(2)O(2) contents were enhanced, and the structure of the wheat mesophyll cell was seriously damaged. Furthermore, transcripts of the chloroplast- and mitochondrial-encoded genes were significantly reduced in TaBTF3-silenced transgenic wheat plants. These results suggest that the TaBTF3 gene might function in the development of the wheat chloroplast, mitochondria and mesophyll cell. This paper is the first report to describe the involvement of TaBTF3 in maintaining the normal plant mesophyll cell structure. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. The heterogeneity of structural and functional photosynthetic characteristics of mesophyll chloroplasts in various parts of mature or senescing leaf blade of two maize (Zea mays L.) genotypes

    Kutík, J.; Holá, D.; Vičánková, A.; Šmídová, M.; Kočová, M.; Körnerová, M.; Kubínová, Lucie

    2001-01-01

    Roč. 39, č. 4 (2001), s. 497-506 ISSN 0300-3604 Grant - others:GA UK(CZ) 103/1998 Institutional research plan: CEZ:AV0Z5011922 Keywords : chloroplast development * electron microscopy Subject RIV: EF - Botanics Impact factor: 0.807, year: 2001

  7. Estimation of mesophyll conductance to CO2 flux by three different methods

    Loreto, F.; Harley, P.C.; Di Marco, G.; Sharkey, T.D.

    1992-01-01

    The resistance to diffusion of CO2 from the intercellular airspaces within the leaf through the mesophyll to the sites of carboxylation during photosynthesis was measured using three different techniques, The three techniques include a method based on discrimination against the heavy stable isotope of carbon, 13C, and two modeling methods. The methods rely upon different assumptions, but the estimates of mesophyll conductance were similar with all three methods. The mesophyll conductance of leaves from a number of species was about 1.4 times the stomatal conductance for CO2 diffusion determined in unstressed plants at high light. The relatively low CO2 partial pressure inside chloroplasts of plants with a low mesophyll conductance did not lead to enhanced O2 sensitivity of photosynthesis because the low conductance caused a significant drop in the chloroplast CO2 Partial pressure upon switching to low O2. We found no correlation between mesophyll conductance and the ratio of internal leaf area to leaf surface area and only a weak correlation between mesophyll conductance and the proportion of leaf volume occupied by air. Mesophyll conductance was independent of CO2 and O2 partial pressure during the measurement, indicating that a true physical parameter, independent of biochemical effects, was being measured. No evidence for accumulating mechanisms was found. Some plants, notably Citrus aurantium and Simmondsia chinensis, had very low conductances that limit the rate of photosynthesis these plants can attain at atmospheric CO2 level

  8. The influence of nitric oxide and mercury chloride on leaf mesophyll structure under natural drought conditions

    Mykola M. Musiyenko

    2012-03-01

    Full Text Available It is established that under natural drought conditions starch was accumulated in the central part of chloroplasts of mesophyll cells and chloroplasts were localized on the periphery of cells at plasmalemma. After treatment wheat plants by nitric oxide donor the decreasing of starch deposits number and close contacts between chloroplasts were indicated, elongated nucleus was localized in the centre of cells. After treatment wheat plant by mercury chloride chloroplasts in the cells lost their oval shape and contacts, increased eventually deposition of starch, indicating the acceleration of aging tissues. Thus, nitric oxide in drought conditions reduced the destructive effect of drought on mesophyll cells, and mercury chloride caused deformation of the membrane cell.

  9. Dynamics of Chloroplast Translation during Chloroplast Differentiation in Maize.

    Prakitchai Chotewutmontri

    2016-07-01

    Full Text Available Chloroplast genomes in land plants contain approximately 100 genes, the majority of which reside in polycistronic transcription units derived from cyanobacterial operons. The expression of chloroplast genes is integrated into developmental programs underlying the differentiation of photosynthetic cells from non-photosynthetic progenitors. In C4 plants, the partitioning of photosynthesis between two cell types, bundle sheath and mesophyll, adds an additional layer of complexity. We used ribosome profiling and RNA-seq to generate a comprehensive description of chloroplast gene expression at four stages of chloroplast differentiation, as displayed along the maize seedling leaf blade. The rate of protein output of most genes increases early in development and declines once the photosynthetic apparatus is mature. The developmental dynamics of protein output fall into several patterns. Programmed changes in mRNA abundance make a strong contribution to the developmental shifts in protein output, but output is further adjusted by changes in translational efficiency. RNAs with prioritized translation early in development are largely involved in chloroplast gene expression, whereas those with prioritized translation in photosynthetic tissues are generally involved in photosynthesis. Differential gene expression in bundle sheath and mesophyll chloroplasts results primarily from differences in mRNA abundance, but differences in translational efficiency amplify mRNA-level effects in some instances. In most cases, rates of protein output approximate steady-state protein stoichiometries, implying a limited role for proteolysis in eliminating unassembled or damaged proteins under non-stress conditions. Tuned protein output results from gene-specific trade-offs between translational efficiency and mRNA abundance, both of which span a large dynamic range. Analysis of ribosome footprints at sites of RNA editing showed that the chloroplast translation machinery

  10. Factors affecting polyhydroxybutyrate accumulation in mesophyll cells of sugarcane and switchgrass

    2014-01-01

    Background Polyhydroxyalkanoates are linear biodegradable polyesters produced by bacteria as a carbon store and used to produce a range of bioplastics. Widespread polyhydroxyalkanoate production in C4 crops would decrease petroleum dependency by producing a renewable supply of biodegradable plastics along with residual biomass that could be converted into biofuels or energy. Increasing yields to commercial levels in biomass crops however remains a challenge. Previously, lower accumulation levels of the short side chain polyhydroxyalkanoate, polyhydroxybutyrate (PHB), were observed in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells in transgenic maize (Zea mays), sugarcane (Saccharum sp.), and switchgrass (Panicum virgatum L.) leading to a significant decrease in the theoretical yield potential. Here we explore various factors which might affect polymer accumulation in mesophyll cells, including targeting of the PHB pathway enzymes to the mesophyll plastid and their access to substrate. Results The small subunit of Rubisco from pea effectively targeted the PHB biosynthesis enzymes to both M and BS chloroplasts of sugarcane and switchgrass. PHB enzyme activity was retained following targeting to M plastids and was equivalent to that found in the BS plastids. Leaf total fatty acid content was not affected by PHB production. However, when fatty acid synthesis was chemically inhibited, polymer accumulated in M cells. Conclusions In this study, we provide evidence that access to substrate and neither poor targeting nor insufficient activity of the PHB biosynthetic enzymes may be the limiting factor for polymer production in mesophyll chloroplasts of C4 plants. PMID:25209261

  11. Three-dimensional intracellular structure of a whole rice mesophyll cell observed with FIB-SEM.

    Oi, Takao; Enomoto, Sakiko; Nakao, Tomoyo; Arai, Shigeo; Yamane, Koji; Taniguchi, Mitsutaka

    2017-07-01

    Ultrathin sections of rice leaf blades observed two-dimensionally using a transmission electron microscope (TEM) show that the chlorenchyma is composed of lobed mesophyll cells, with intricate cell boundaries, and lined with chloroplasts. The lobed cell shape and chloroplast positioning are believed to enhance the area available for the gas exchange surface for photosynthesis in rice leaves. However, a cell image revealing the three-dimensional (3-D) ultrastructure of rice mesophyll cells has not been visualized. In this study, a whole rice mesophyll cell was observed using a focused ion beam scanning electron microscope (FIB-SEM), which provides many serial sections automatically, rapidly and correctly, thereby enabling 3-D cell structure reconstruction. Rice leaf blades were fixed chemically using the method for conventional TEM observation, embedded in resin and subsequently set in the FIB-SEM chamber. Specimen blocks were sectioned transversely using the FIB, and block-face images were captured using the SEM. The sectioning and imaging were repeated overnight for 200-500 slices (each 50 nm thick). The resultant large-volume image stacks ( x = 25 μm, y = 25 μm, z = 10-25 μm) contained one or two whole mesophyll cells. The 3-D models of whole mesophyll cells were reconstructed using image processing software. The reconstructed cell models were discoid shaped with several lobes around the cell periphery. The cell shape increased the surface area, and the ratio of surface area to volume was twice that of a cylinder having the same volume. The chloroplasts occupied half the cell volume and spread as sheets along the cell lobes, covering most of the inner cell surface, with adjacent chloroplasts in close contact with each other. Cellular and sub-cellular ultrastructures of a whole mesophyll cell in a rice leaf blade are demonstrated three-dimensionally using a FIB-SEM. The 3-D models and numerical information support the hypothesis that rice mesophyll

  12. Asymmetrical effects of mesophyll conductance on fundamental photosynthetic parameters and their relationships estimated from leaf gas exchange measurements

    Most previous analyses of leaf gas exchange measurements assumed an infinite value of mesophyll conductance (gm) and thus equaled CO2 partial pressures in the substomatal cavity and chloroplast. Yet an increasing number of studies have recognized that gm is finite and there is a drawdown of CO2 part...

  13. Effects of shading on the photosynthetic characteristics and mesophyll cell ultrastructure of summer maize.

    Ren, Baizhao; Cui, Haiyan; Camberato, James J; Dong, Shuting; Liu, Peng; Zhao, Bin; Zhang, Jiwang

    2016-08-01

    A field experiment was conducted to study the effects of shading on the photosynthetic characteristics and mesophyll cell ultrastructure of two summer maize hybrids Denghai605 (DH605) and Zhengdan958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth stages from silking (R1) to physiological maturity (R6) (S1), from the sixth leaf stage (V6) to R1 (S2), and from seeding to R6 (S3), respectively. The net photosynthetic rate (P n) was significantly decreased after shading. The greatest reduction of P n was found at S3 treatment, followed by S1 and S2 treatments. P n of S3 was decreased by 59 and 48 % for DH605, and 39 and 43 % for ZD958 at tasseling and milk-ripe stages, respectively, compared to that of CK. Additionally, leaf area index (LAI) and chlorophyll content decreased after shading. In terms of mesophyll cell ultrastructure, chloroplast configuration of mesophyll cells dispersed, and part of chloroplast swelled and became circular. Meanwhile, the major characteristics of chloroplasts showed poorly developed thylakoid structure at the early growth stage, blurry lamellar structure, loose grana, and a large gap between slices and warping granum. Then, plasmolysis occurred in mesophyll cells and the endomembrane system was destroyed, which resulted in the dissolution of cell membrane, karyotheca, mitochondria, and some membrane structures. The damaged mesophyll cell ultrastructure led to the decrease of photosynthetic capacity, and thus resulted in significant yield reduction by 45, 11, and 84 % in S1, S2, and S3 treatments, respectively, compared to that of CK.

  14. Longevity of guard cell chloroplasts in falling leaves: implication for stomatal function and cellular aging.

    Zeiger, E; Schwartz, A

    1982-11-12

    Guard cell chloroplasts in senescing leaves from 12 species of perennial trees and three species of annual plants survived considerably longer than their mesophyll counterparts. In Ginkgo biloba, stomata from yellow leaves opened during the day and closed at night; guard cell chloroplasts from these leaves showed fluorescence transients associated with electron transport and photophosphorylation. These findings indicate that guard cell chloroplasts are highly conserved throughout the life-span of the leaf and that leaves retain stomatal control during senescence.

  15. C4 photosynthetic machinery: insights from maize chloroplast proteomics

    Qi eZhao

    2013-04-01

    Full Text Available C4 plants exhibit much higher CO2 assimilation rates than C3 plants. The specialized differentiation of mesophyll cell (M and bundle sheath cell (BS type chloroplasts is unique to C4 plants and improves photosynthesis efficiency. Maize (Zea mays is an important crop and model with C4 photosynthetic machinery. Current high-throughput quantitative proteomics approaches (e.g., 2DE, iTRAQ, and shotgun proteomics have been employed to investigate maize chloroplast structure and function. These proteomic studies have provided valuable information on C4 chloroplast protein components, photosynthesis, and other metabolic mechanisms underlying chloroplast biogenesis, stromal and membrane differentiation, as well as response to salinity, high/low temperature, and light stress. This review presents an overview of proteomics advances in maize chloroplast biology.

  16. Air pollution effects on the ultrastructure of Phlomis fruticosa mesophyll cells

    Psaras, G.K.; Christodoulakis, N.S.

    1987-04-01

    Plant physiologists and environmental scientists suggest that a basic effect of air pollution on plants leads towards the minimization of their productivity. On the other hand the action of individual pollutants on intact plants has been studied from biochemical as well as structural viewpoint. Thus the study of plant responses to SO/sub 2/ exposure revealed that this agent causes acute and chronic injury. Chronic injury results in chlorosis and subsequent necrosis due to destruction of chlorophylls and final chloroplast lysis. It has been documented that ultrastructural characteristics of leaves are affected prior to any visible injury. Electron microscope examination of SO/sub 2/ fumigated plant-attached leaves of Vicia faba revealed chloroplast thylakoids starting to swell whilst photosynthesis rate was drastically reduced. The first light microscope-detected effects of air pollution on the leaf structure of plants common in natural ecosystems of Athens metropolitan area, have been reported. A chlorosis phenomenon in Urginea maritima leaves as well as an indication of detrimental effects of Phlomis fruticosa mesophyll chloroplasts were documented. In this work further investigation has been undertaken in order to elucidate the precise effects of air pollution on the ultrastructure of the photosynthesizing mesophyll cells.

  17. Stomatal conductance, mesophyll conductance, and transpiration efficiency in relation to leaf anatomy in rice and wheat genotypes under drought.

    Ouyang, Wenjing; Struik, Paul C; Yin, Xinyou; Yang, Jianchang

    2017-11-02

    Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (gs) and mesophyll conductance (gm) and their anatomical determinants were evaluated in two cultivars from each of lowland, aerobic, and upland groups of Oryza sativa, one cultivar of O. glaberrima, and two cultivars of T. aestivum, under three water regimes. The TE of upland rice, O. glaberrima, and wheat was more responsive to the gm/gs ratio than that of lowland and aerobic rice. Overall, the explanatory power of the particular anatomical trait varied among species. Low stomatal density mostly explained the low gs in drought-tolerant rice, whereas rice genotypes with smaller stomata generally responded more strongly to drought. Compared with rice, wheat had a higher gm, which was associated with thicker mesophyll tissue, mesophyll and chloroplasts more exposed to intercellular spaces, and thinner cell walls. Upland rice, O. glaberrima, and wheat cultivars minimized the decrease in gm under drought by maintaining high ratios of chloroplasts to exposed mesophyll cell walls. Rice TE could be improved by increasing the gm/gs ratio via modifying anatomical traits. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  18. Chloroplast behaviour and interactions with other organelles in Arabidopsis thaliana pavement cells.

    Barton, Kiah A; Wozny, Michael R; Mathur, Neeta; Jaipargas, Erica-Ashley; Mathur, Jaideep

    2018-01-29

    Chloroplasts are a characteristic feature of green plants. Mesophyll cells possess the majority of chloroplasts and it is widely believed that, with the exception of guard cells, the epidermal layer in most higher plants does not contain chloroplasts. However, recent observations on Arabidopsis thaliana have shown a population of chloroplasts in pavement cells that are smaller than mesophyll chloroplasts and have a high stroma to grana ratio. Here, using stable transgenic lines expressing fluorescent proteins targeted to the plastid stroma, plasma membrane, endoplasmic reticulum, tonoplast, nucleus, mitochondria, peroxisomes, F-actin and microtubules, we characterize the spatiotemporal relationships between the pavement cell chloroplasts (PCCs) and their subcellular environment. Observations on the PCCs suggest a source-sink relationship between the epidermal and the mesophyll layers, and experiments with the Arabidopsis mutants glabra2 ( gl2 ) and immutans ( im ), which show altered epidermal plastid development, underscored their developmental plasticity. Our findings lay down the foundation for further investigations aimed at understanding the precise role and contributions of PCCs in plant interactions with the environment. © 2018. Published by The Company of Biologists Ltd.

  19. Pb-induced avoidance-like chloroplast movements in fronds of Lemna trisulca L.

    Sławomir Samardakiewicz

    Full Text Available Lead ions are particularly dangerous to the photosynthetic apparatus, but little is known about the effects of trace metals, including Pb, on regulation of chloroplast redistribution. In this study a new effect of lead on chloroplast distribution patterns and movements was demonstrated in mesophyll cells of a small-sized aquatic angiosperm Lemna trisulca L. (star duckweed. An analysis of confocal microscopy images of L. trisulca fronds treated with lead (15 μM Pb2+, 24 h in darkness or in weak white light revealed an enhanced accumulation of chloroplasts in the profile position along the anticlinal cell walls, in comparison to untreated plants. The rearrangement of chloroplasts in their response to lead ions in darkness was similar to the avoidance response of chloroplasts in plants treated with strong white light. Transmission electron microscopy X-ray microanalysis showed that intracellular chloroplast arrangement was independent of the location of Pb deposits, suggesting that lead causes redistribution of chloroplasts, which looks like a light-induced avoidance response, but is not a real avoidance response to the metal. Furthermore, a similar redistribution of chloroplasts in L. trisulca cells in darkness was observed also under the influence of exogenously applied hydrogen peroxide (H2O2. In addition, we detected an enhanced accumulation of endogenous H2O2 after treatment of plants with lead. Interestingly, H2O2-specific scavenger catalase partly abolished the Pb-induced chloroplast response. These results suggest that H2O2 can be involved in the avoidance-like movement of chloroplasts induced by lead. Analysis of photometric measurements revealed also strong inhibition (but not complete of blue-light-induced chloroplast movements by lead. This inhibition may result from disturbances in the actin cytoskeleton, as we observed fragmentation and disappearance of actin filaments around chloroplasts. Results of this study show that the

  20. Abscisic Acid Induces Rapid Reductions in Mesophyll Conductance to Carbon Dioxide.

    Giuseppe Sorrentino

    Full Text Available The rate of photosynthesis (A of plants exposed to water deficit is a function of stomatal (gs and mesophyll (gm conductance determining the availability of CO2 at the site of carboxylation within the chloroplast. Mesophyll conductance often represents the greatest impediment to photosynthetic uptake of CO2, and a crucial determinant of the photosynthetic effects of drought. Abscisic acid (ABA plays a fundamental role in signalling and co-ordination of plant responses to drought; however, the effect of ABA on gm is not well-defined. Rose, cherry, olive and poplar were exposed to exogenous ABA and their leaf gas exchange parameters recorded over a four hour period. Application with ABA induced reductions in values of A, gs and gm in all four species. Reduced gm occurred within one hour of ABA treatment in three of the four analysed species; indicating that the effect of ABA on gm occurs on a shorter timescale than previously considered. These declines in gm values associated with ABA were not the result of physical changes in leaf properties due to altered turgor affecting movement of CO2, or caused by a reduction in the sub-stomatal concentration of CO2 (Ci. Increased [ABA] likely induces biochemical changes in the properties of the interface between the sub-stomatal air-space and mesophyll layer through the actions of cooporins to regulate the transport of CO2. The results of this study provide further evidence that gm is highly responsive to fluctuations in the external environment, and stress signals such as ABA induce co-ordinated modifications of both gs and gm in the regulation of photosynthesis.

  1. Excess Diffuse Light Absorption in Upper Mesophyll Limits CO2 Drawdown and Depresses Photosynthesis.

    Earles, J Mason; Théroux-Rancourt, Guillaume; Gilbert, Matthew E; McElrone, Andrew J; Brodersen, Craig R

    2017-06-01

    In agricultural and natural systems, diffuse light can enhance plant primary productivity due to deeper penetration into and greater irradiance of the entire canopy. However, for individual sun-grown leaves from three species, photosynthesis is actually less efficient under diffuse compared with direct light. Despite its potential impact on canopy-level productivity, the mechanism for this leaf-level diffuse light photosynthetic depression effect is unknown. Here, we investigate if the spatial distribution of light absorption relative to electron transport capacity in sun- and shade-grown sunflower ( Helianthus annuus ) leaves underlies its previously observed diffuse light photosynthetic depression. Using a new one-dimensional porous medium finite element gas-exchange model parameterized with light absorption profiles, we found that weaker penetration of diffuse versus direct light into the mesophyll of sun-grown sunflower leaves led to a more heterogenous saturation of electron transport capacity and lowered its CO 2 concentration drawdown capacity in the intercellular airspace and chloroplast stroma. This decoupling of light availability from photosynthetic capacity under diffuse light is sufficient to generate an 11% decline in photosynthesis in sun-grown but not shade-grown leaves, primarily because thin shade-grown leaves similarly distribute diffuse and direct light throughout the mesophyll. Finally, we illustrate how diffuse light photosynthetic depression could overcome enhancement in canopies with low light extinction coefficients and/or leaf area, pointing toward a novel direction for future research. © 2017 American Society of Plant Biologists. All Rights Reserved.

  2. Changes in photosynthesis, mesophyll conductance to CO2, and isoprenoid emissions in Populus nigra plants exposed to excess nickel

    Velikova, Violeta; Tsonev, Tsonko; Loreto, Francesco; Centritto, Mauro

    2011-01-01

    Poplar (Populus nigra) plants were grown hydroponically with 30 and 200 μM Ni (Ni 30 and Ni 200 ). Photosynthesis limitations and isoprenoid emissions were investigated in two leaf types (mature and developing). Ni stress significantly decreased photosynthesis, and this effect depended on the leaf Ni content, which was lower in mature than in developing leaves. The main limitations to photosynthesis were attributed to mesophyll conductance and metabolism impairment. In Ni-stressed developing leaves, isoprene emission was significantly stimulated. We attribute such stimulation to the lower chloroplastic [CO 2 ] than in control leaves. However chloroplastic [CO 2 ] did not control isoprene emission in mature leaves. Ni stress induced the emission of cis-β-ocimene in mature leaves, and of linalool in both leaf types. Induced biosynthesis and emission of isoprenoids reveal the onset of antioxidant processes that may also contribute to reduce Ni stress, especially in mature poplar leaves. - Graphical abstract: Visible damage caused by Ni treatment. 1 - Ni 0 (control plants); 2 - Ni 200 ; M = mature and D = developing Populus nigra leaves. Display Omitted Highlights: → We study the effect of Ni pollution on photosynthesis and isoprenoid emissions. → Ni stress significantly decreases photosynthesis. The main limitations are attributed to mesophyll conductance and metabolism impairment. → Constitutive isoprene emission was significantly stimulated in Ni-stressed leaves. Exposure to enhanced Ni concentration induces cis-beta-ocimene and linalool emissions. - The study reveals consequences of Ni stress on plant physiology, namely increasing diffusional limitation to photosynthesis and isoprenoid emissions.

  3. Crude petroleum

    1990-01-01

    Crude petroleum statistics by country of production, export values and import values from 1983 to 1988 are given. Table A.1 of the Annex includes free market prices and price indices for crude petroleum based on average of Dubai, United Kingdom Brent and Alaska N Slope crude prices (price expressed in dollars/barrel). The data sources are: Crude petroleum United Nations Statistical Office; OPEC Annual Statistical Bulletin, and Petroleum Economist. For trade the sources of data are: National trade statistics; United Nations international trade statistics; International Moneytary Fund (IMF); Organization of the Petroleum Exporting Countries (OPEC); UNCTAD secretariat estimates. Tabs

  4. Ozone-induced changes in the chloroplast structure of conifer needles, and their use in ozone diagnostics

    Kivimaeenpaeae, M.; Sellden, G.; Sutinen, S.

    2005-01-01

    Ozone induces characteristic symptoms in the chloroplasts of the needles of several coniferous species. Chloroplasts are (1) reduced in size and (2) the stroma is electron dense. Moreover (3) these chloroplast alterations are more pronounced in the outer mesophyll cell layers and in the upper side of the needle compared to the inner layers and lower side. The syndrome, including the three symptoms (1)-(3), is found in the green needles of Scots pine and Norway spruce not only in the experimental fumigations, but also in mature trees in the field, and has potential for diagnosis of ozone stress. For sound ozone diagnostics all three symptoms must be present in the samples studied. The symptoms in relation to needle anatomy and physiology is discussed, and recommendations for sampling and analysis are given. - Ozone-induced alterations in chloroplast structure of conifer needles are reviewed, and recommendations for field monitoring given

  5. Ultrastructural response of cabbage outer leaf mesophyll cells (Brassica oleracea L. to excess of nickel

    Jolanta Molas

    2014-01-01

    Full Text Available Changes in the structure and in the ultrastructure of cabbage outer leaf mesophyll cells [Brassica oleracea L.] cv. Sława from Enkhouizen were examined by means of light and electron microscopy. The examined plants were grown on the basic Murashige and Skoog medium with addition of excesive concentrations of nickel (added as NiSO4 x 7H2O,i.e. Ni 5, Ni 10 and Ni 20 mg/dm3. In Ni 5 mg samples mainly adaptation changes to the conditions of stress were observed. These changes were manifested by the increase of cytoplasm content and by cytoplasm vacuolization, by the increase of nucleus and nucleous volume, nucleolus vacuolization, the increase of plasmalemma invaginations and of the amount of rough ER, by the central arrangement of smooth ER and of the thylakoids of chloroplasts; it was also shown by the growth of the number of mitochondria and of peroxisomes in the cell. In Ni 10 mg samples, apart from adaptation changes, such as the increase of the nucleus volume, increase of plasmalemma invaginations, cytoplasm and nucleolus vacuolization, degeneration changes were also observed. They concerned mainly the nucleus (the increasing amount of condensed chromatin, ER (swelling and fragmentation of rER and sER, mitochondrium (swelling and reduction of cristae, Golgi apparatus (disintegration and decay and chloroplasts (changes of shape, swelling and reduction of thylakoids, disappearance of starch and presence of big plastoglobuli. In Ni 20 mg samples cell protoplasts were in different stages of degeneration and the cell organelles that were identifiable, were usually damaged.

  6. Chloroplast Redox Poise

    Steccanella, Verdiana

    the redox status of the plastoquinone pool and chlorophyll biosynthesis. Furthermore, in the plant cell, the equilibrium between redox reactions and ROS signals is also maintained by various balancing mechanisms among which the thioredoxin reductase-thioredoxin system (TR-Trx) stands out as a mediator......The redox state of the chloroplast is maintained by a delicate balance between energy production and consumption and is affected by the need to avoid increased production of reactive oxygen species (ROS). Redox power and ROS generated in the chloroplast are essential for maintaining physiological...... metabolic pathways and for optimizing chloroplast functions. The redox poise of photosynthetic electron transport components like plastoquinone is crucial to initiate signaling cascades and might also be involved in key biosynthetic pathways such as chlorophyll biosynthesis. We, therefore, explored...

  7. Dichroism in spinach chloroplasts

    Thomas, J.B.; Lierop, J.H. van; Ham, M. ten

    1967-01-01

    In spinach chloroplasts oriented at steel-water interfaces parallel to the light beam a distinct dichroism is measured at about 680 nm. This dichroism is minimal upon addition of sucrose up to a final concentration of 0.18 M to the medium, the dichroic ratio amounting to 1.02. It is concluded that

  8. A simple low-cost microcontroller-based photometric instrument for monitoring chloroplast movement.

    Berg, Robert; Königer, Martina; Schjeide, Brit-Maren; Dikmak, George; Kohler, Susan; Harris, Gary C

    2006-03-01

    A new microcontroller-based photometric instrument for monitoring blue light dependent changes in leaf transmission (chloroplast movement) was developed based on a modification of the double-beam technique developed by Walzcak and Gabrys [(1980) Photosynthetica 14: 65-72]. A blue and red bicolor light emitting diode (LED) provided both a variable intensity blue actinic light and a low intensity red measuring beam. A phototransistor detected the intensity of the transmitted measuring light. An inexpensive microcontroller independently and precisely controlled the light emission of the bicolor LED. A typical measurement event involved turning off the blue actinic light for 100 mus to create a narrow temporal window for turning on and measuring the transmittance of the red light. The microcontroller was programmed using LogoChip Logo (http://www.wellesley.edu/Physics/Rberg/logochip/) to record fluence rate response curves. Laser scanning confocal microscopy was utilized to correlate the changes in leaf transmission with intercellular chloroplast position. In the dark, the chloroplasts in the spongy mesophyll exhibited no evident asymmetries in their distribution, however, in the palisade layer the cell surface in contact with the overlying epidermis was devoid of chloroplasts. The low light dependent decrease in leaf transmittance in dark acclimated leaves was correlated with the movement of chloroplasts within the palisade layer into the regions previously devoid of chloroplasts. Changes in leaf transmittance were evident within one minute following the onset of illumination. Minimal leaf transmittance was correlated with chloroplasts having retreated from cell surfaces perpendicular to the incident light (avoidance reaction) in both spongy and palisade layers.

  9. Infection of potato mesophyll protoplasts with five plant viruses.

    Barker, H; Harrison, B D

    1982-12-01

    Methods are described for preparing potato mesophyll protoplasts that are suitable for infection with inocula of virus nucleoprotein or RNA. The protoplasts could be infected with four sap-transmissible viruses (tobacco mosaic, tobacco rattle, tobacco ringspot and tomato black ring viruses) and with potato leafroll virus, which is not saptransmissible. No differences were observed in ability to infect protoplasts with potato leafroll virus strains differing either in virulence in intact plants or in aphid transmissibility.

  10. Measurement of gross photosynthesis, respiration in the light, and mesophyll conductance using H218O labeling.

    Gauthier, Paul Pg; Battle, Mark O; Griffin, Kevin L; Bender, Michael L

    2018-03-27

    A fundamental challenge in plant physiology is independently determining the rates of gross O2 production by photosynthesis and O2 consumption by respiration, photorespiration, and other processes. Previous studies on isolated chloroplasts or leaves have separately constrained net and gross O2 production (NOP and GOP, respectively) by labeling ambient O2 with 18O while leaf water was unlabeled. Here, we describe a method to accurately measure GOP and NOP of whole detached leaves in a cuvette as a routine gas exchange measurement. The petiole is immersed in water enriched to a δ18O of ~9,000‰, and leaf water is labeled through the transpiration stream. Photosynthesis transfers 18O from H2O to O2. GOP is calculated from the increase in δ18O of O2 as air passes through the cuvette. NOP is determined from the increase in O2/N2. Both terms are measured by isotope ratio mass spectrometry. CO2 assimilation and other standard gas exchange parameters are also measured. Reproducible measurements are made on a single leaf for more than 15 hours. We used this method to measure the light response curve of NOP and GOP in Phaseolus vulgaris at 21% and 2% O2. We then used these data to examine the O2/CO2 ratio of net photosynthesis, the light response curve of mesophyll conductance, and the apparent inhibition of respiration in the light (Kok effect) at both oxygen levels. The results are discussed in the context of evaluating the technique as a tool to study and understand leaf physiological traits. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

  11. Effects of potentially acidic air pollutants on the intracellular distribution and transport of plant growth regulators in mesophyll cells of leaves. Consequences on stress- and developmental physiology

    Kremer, H.; Pfanz, H.; Hartung, W.

    1987-07-11

    The influence of SO/sub 2/ on the intracellular distribution of abscisic acid (ABA) and indole-acetic acid (IAA) in mesophyll cells of Picea abies, Tsuga americana and Hordeum vulgare was investigated. The compartmentation of ABA and IAA depends on intracellular pH-gradients. The hydrophilic anions ABA and IAA are accumulated in the alkaline cell compartments cytosol and chloroplasts, which act as anion traps for weak acids. Uptake of sulfur dioxide into leaves leads to an acidification of alkaline cell compartments, thus decreasing intracellular pH-gradients. Consequently this results in an increased release of plant growth regulators from the cell interior into the apoplast. Therefore the target cells of plant hormones i.e. meristems and stomates are exposed to altered hormone concentrations. Obviously this influences the regulation of cellular metabolism plant development and growth.

  12. Protein import into chloroplasts requires a chloroplast ATPase

    Pain, D.; Blobel, G.

    1987-01-01

    The authors have transcribed mRNA from a cDNA clone coding for pea ribulose-1,5-bisphosphate carboxylase, translated the mRNA in a wheat germ cell-free system, and studied the energy requirement for posttranslational import of the [ 35 S]methionine-labeled protein into the stroma of pea chloroplasts. They found that import depends on ATP hydrolysis within the stroma. Import is not inhibited when H + , K + , Na + , or divalent cation gradients across the chloroplast membranes are dissipated by ionophores, as long as exogenously added ATP is also present during the import reaction. The data suggest that protein import into the chloroplast stroma requires a chloroplast ATPase that does not function to generate a membrane potential for driving the import reaction but that exerts its effect in another, yet-to-be-determined, mode. They have carried out a preliminary characterization of this ATPase regarding its nucleotide specificity and the effects of various ATPase inhibitors

  13. Using tunable diode laser spectroscopy to measure carbon isotope discrimination and mesophyll conductance to CO₂ diffusion dynamically at different CO₂ concentrations.

    Tazoe, Youshi; VON Caemmerer, Susanne; Estavillo, Gonzalo M; Evans, John R

    2011-04-01

    In C₃ leaves, the mesophyll conductance to CO₂ diffusion, g(m) , determines the drawdown in CO₂ concentration from intercellular airspace to the chloroplast stroma. Both g(m) and stomatal conductance limit photosynthetic rate and vary in response to the environment. We investigated the response of g(m) to changes in CO₂ in two Arabidopsis genotypes (including a mutant with open stomata, ost1), tobacco and wheat. We combined measurements of gas exchange with carbon isotope discrimination using tunable diode laser absorption spectroscopy with a CO₂ calibration system specially designed for a range of CO₂ and O₂ concentrations. CO₂ was initially increased from 200 to 1000 ppm and then decreased stepwise to 200 ppm and increased stepwise back to 1000 ppm, or the sequence was reversed. In 2% O₂ a step increase from 200 to 1000 ppm significantly decreased g(m) by 26-40% in all three species, whereas following a step decrease from 1000 to 200 ppm, the 26-38% increase in g(m) was not statistically significant. The response of g(m) to CO₂ was less in 21% O₂. Comparing wild type against the ost1 revealed that mesophyll and stomatal conductance varied independently in response to CO₂. We discuss the effects of isotope fractionation factors on estimating g(m) . © 2011 Blackwell Publishing Ltd.

  14. Changes in photosynthesis, mesophyll conductance to CO{sub 2}, and isoprenoid emissions in Populus nigra plants exposed to excess nickel

    Velikova, Violeta, E-mail: violet@obzor.bio21.bas.bg [Bulgarian Academy of Sciences, Acad. M. Popov Institute of Plant Physiology, Acad. G. Bonchev, Bl. 21, 1113 Sofia (Bulgaria); Tsonev, Tsonko [Bulgarian Academy of Sciences, Acad. M. Popov Institute of Plant Physiology, Acad. G. Bonchev, Bl. 21, 1113 Sofia (Bulgaria); Loreto, Francesco [Consiglio Nazionale delle Ricerche, Istituto per la Protezione delle Piante, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze (Italy); Centritto, Mauro [Consiglio Nazionale delle Ricerche, Istituto di Biologia Agroambientale e Forestale, 00015 Monterotondo Scalo (RM) (Italy)

    2011-05-15

    Poplar (Populus nigra) plants were grown hydroponically with 30 and 200 {mu}M Ni (Ni{sub 30} and Ni{sub 200}). Photosynthesis limitations and isoprenoid emissions were investigated in two leaf types (mature and developing). Ni stress significantly decreased photosynthesis, and this effect depended on the leaf Ni content, which was lower in mature than in developing leaves. The main limitations to photosynthesis were attributed to mesophyll conductance and metabolism impairment. In Ni-stressed developing leaves, isoprene emission was significantly stimulated. We attribute such stimulation to the lower chloroplastic [CO{sub 2}] than in control leaves. However chloroplastic [CO{sub 2}] did not control isoprene emission in mature leaves. Ni stress induced the emission of cis-{beta}-ocimene in mature leaves, and of linalool in both leaf types. Induced biosynthesis and emission of isoprenoids reveal the onset of antioxidant processes that may also contribute to reduce Ni stress, especially in mature poplar leaves. - Graphical abstract: Visible damage caused by Ni treatment. 1 - Ni{sub 0} (control plants); 2 - Ni{sub 200}; M = mature and D = developing Populus nigra leaves. Display Omitted Highlights: > We study the effect of Ni pollution on photosynthesis and isoprenoid emissions. > Ni stress significantly decreases photosynthesis. The main limitations are attributed to mesophyll conductance and metabolism impairment. > Constitutive isoprene emission was significantly stimulated in Ni-stressed leaves. Exposure to enhanced Ni concentration induces cis-beta-ocimene and linalool emissions. - The study reveals consequences of Ni stress on plant physiology, namely increasing diffusional limitation to photosynthesis and isoprenoid emissions.

  15. Asymmetrical effects of mesophyll conductance on fundamental photosynthetic parameters and their relationships estimated from leaf gas exchange measurements.

    Sun, Ying; Gu, Lianhong; Dickinson, Robert E; Pallardy, Stephen G; Baker, John; Cao, Yonghui; DaMatta, Fábio Murilo; Dong, Xuejun; Ellsworth, David; Van Goethem, Davina; Jensen, Anna M; Law, Beverly E; Loos, Rodolfo; Martins, Samuel C Vitor; Norby, Richard J; Warren, Jeffrey; Weston, David; Winter, Klaus

    2014-04-01

    Worldwide measurements of nearly 130 C3 species covering all major plant functional types are analysed in conjunction with model simulations to determine the effects of mesophyll conductance (g(m)) on photosynthetic parameters and their relationships estimated from A/Ci curves. We find that an assumption of infinite g(m) results in up to 75% underestimation for maximum carboxylation rate V(cmax), 60% for maximum electron transport rate J(max), and 40% for triose phosphate utilization rate T(u) . V(cmax) is most sensitive, J(max) is less sensitive, and T(u) has the least sensitivity to the variation of g(m). Because of this asymmetrical effect of g(m), the ratios of J(max) to V(cmax), T(u) to V(cmax) and T(u) to J(max) are all overestimated. An infinite g(m) assumption also limits the freedom of variation of estimated parameters and artificially constrains parameter relationships to stronger shapes. These findings suggest the importance of quantifying g(m) for understanding in situ photosynthetic machinery functioning. We show that a nonzero resistance to CO2 movement in chloroplasts has small effects on estimated parameters. A non-linear function with gm as input is developed to convert the parameters estimated under an assumption of infinite gm to proper values. This function will facilitate gm representation in global carbon cycle models. © 2013 John Wiley & Sons Ltd.

  16. Interaction of E. coli DNA with tobacco mesophyll protoplasts

    Heyn, R.F.

    1975-01-01

    This chapter is part of a dissertation dealing with the interaction of DNA with protoplasts. Having established the length of time during which tobacco mesophyll protoplasts do not synthesize DNA following their isolation, it is important to know the extent of DNA uptake just before the onset of DNA synthesis (and possible integration) and to find optimal conditions for this uptake. Therefore, the association of E. coli DNA with tobacco protoplasts was studied. Care should be taken with the interpretation of ''uptake'' results: adsorption phenomena play a very important role and may do so at the plasmalemma of naked protoplasts. To solve the problems involved, the use of radiation-damaged DNA was attempted. With E. coli DNA possessing a large number of thymine containing pyrimidine dimers, the loss of dimers from DNA recovered from treated protoplasts was tested in order to obtain an indication of ''real'' uptake. The results are reported

  17. Towards a synthetic chloroplast.

    Christina M Agapakis

    2011-04-01

    Full Text Available The evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria, leading to the formation of mitochondria or chloroplasts, respectively. Engineered endosymbiotic relationships between different species of cells are a valuable tool for synthetic biology, where engineered pathways based on two species could take advantage of the unique abilities of each mutualistic partner.We explored the possibility of using the photosynthetic bacterium Synechococcus elongatus PCC 7942 as a platform for studying evolutionary dynamics and for designing two-species synthetic biological systems. We observed that the cyanobacteria were relatively harmless to eukaryotic host cells compared to Escherichia coli when injected into the embryos of zebrafish, Danio rerio, or taken up by mammalian macrophages. In addition, when engineered with invasin from Yersinia pestis and listeriolysin O from Listeria monocytogenes, S. elongatus was able to invade cultured mammalian cells and divide inside macrophages.Our results show that it is possible to engineer photosynthetic bacteria to invade the cytoplasm of mammalian cells for further engineering and applications in synthetic biology. Engineered invasive but non-pathogenic or immunogenic photosynthetic bacteria have great potential as synthetic biological devices.

  18. Protein import into chloroplasts requires a chloroplast ATPase

    Pain, D.; Blobel, G.

    1987-05-01

    The authors have transcribed mRNA from a cDNA clone coding for pea ribulose-1,5-bisphosphate carboxylase, translated the mRNA in a wheat germ cell-free system, and studied the energy requirement for posttranslational import of the (/sup 35/S)methionine-labeled protein into the stroma of pea chloroplasts. They found that import depends on ATP hydrolysis within the stroma. Import is not inhibited when H/sup +/, K/sup +/, Na/sup +/, or divalent cation gradients across the chloroplast membranes are dissipated by ionophores, as long as exogenously added ATP is also present during the import reaction. The data suggest that protein import into the chloroplast stroma requires a chloroplast ATPase that does not function to generate a membrane potential for driving the import reaction but that exerts its effect in another, yet-to-be-determined, mode. They have carried out a preliminary characterization of this ATPase regarding its nucleotide specificity and the effects of various ATPase inhibitors.

  19. Carbon isotope ratios of epidermal and mesophyll tissues from leaves of C3 and CAM plants

    Nishida, K.; Roksandic, Z.; Osmond, B.

    1981-01-01

    The δ 13 C values for epidermal and mesophyll tissues of two C 3 plants, Commelina communis and Tulipa gesneriana, and a CAM plant, Kalanchoē daigremontiana, were measured. The values for the tissues of both C 3 plants were similar. In young leaves of Kalanchoē, the epidermis and the mesophyll showed S 13 C values which were nearly identical, and similar to those found in C 3 plants. However, markedly more negative values for epidermal compared to mesophyll tissue, were obtained in the mature Kalanchoē leaf. This is consistent with the facts that the epidermis in a CAM leaf is formed when leaves engage in C 3 photosynthesis and that subsequent dark CO 2 fixation in guard cells or mesophyll cells makes only a small contribution to total epidermal carbon

  20. Metabolomic Responses of Guard Cells and Mesophyll Cells to Bicarbonate

    Misra, Biswapriya B.; de Armas, Evaldo; Tong, Zhaohui; Chen, Sixue

    2015-01-01

    Anthropogenic CO2 presently at 400 ppm is expected to reach 550 ppm in 2050, an increment expected to affect plant growth and productivity. Paired stomatal guard cells (GCs) are the gate-way for water, CO2, and pathogen, while mesophyll cells (MCs) represent the bulk cell-type of green leaves mainly for photosynthesis. We used the two different cell types, i.e., GCs and MCs from canola (Brassica napus) to profile metabolomic changes upon increased CO2 through supplementation with bicarbonate (HCO3 -). Two metabolomics platforms enabled quantification of 268 metabolites in a time-course study to reveal short-term responses. The HCO3 - responsive metabolomes of the cell types differed in their responsiveness. The MCs demonstrated increased amino acids, phenylpropanoids, redox metabolites, auxins and cytokinins, all of which were decreased in GCs in response to HCO3 -. In addition, the GCs showed differential increases of primary C-metabolites, N-metabolites (e.g., purines and amino acids), and defense-responsive pathways (e.g., alkaloids, phenolics, and flavonoids) as compared to the MCs, indicating differential C/N homeostasis in the cell-types. The metabolomics results provide insights into plant responses and crop productivity under future climatic changes where elevated CO2 conditions are to take center-stage. PMID:26641455

  1. Formation of putative chloroplast cytochromes in isolated developing pea chloroplasts

    Thaver, S.S.; Bhava, D.; Castelfranco, P.A.

    1986-01-01

    In addition to chlorophyll-protein complexes, other proteins were labeled when isolated developing pea chloroplasts were incubated with [ 14 C]-5-aminolevulinic acid [ 14 C]-ALA. The major labeled band (M/sub r/ = 43 kDa by LDS-PAGE) was labeled even in the presence of chloramphenicol. Heme-dependent peroxidase activity (as detected by the tetramethyl benzidine-H 2 O 2 stain) was not visibly associated with this band. The radioactive band was stable to heat, 5% HCl in acetone, and was absent if the incubation with [ 14 C]-5-aminolevulinic acid was carried out in the presence of N-methyl protoporphyrin IX dimethyl ester (a specific inhibitor of ferrochelatase). Organic solvent extraction procedures for the enrichment of cytochrome f from chloroplast membranes also extracted this unknown labeled product. It was concluded that this labeled product was probably a c-type cytochrome. The effect of exogenous iron, iron chelators, gabaculine (an inhibitor of ALA synthesis) and other incubation conditions upon the in vitro formation of putative chloroplast cytochromes will be discussed

  2. FUNCTION OF MALATDEHYDROGENASE COMPLEX OF MAIZE MESOPHYLL AND BUNDLE SHEATH CELLS UNDER SALT STRESS CONDITION

    Еprintsev А.Т.

    2006-12-01

    Full Text Available Salt-induced changes in malatdehydrogenase system activity make the essential contribution to cell adaptation to stress condition. The enzyme systems of C4-plants are most interesting due to their ability for adaptation to environment conditions. The role of separate components of malatdehydrogenase complex of mesophyll and bundle sheath cells of corn in formation of adaptive reaction in stressful conditions is investigated in presented work.The activation of all enzymes of malatdehydrogenase system and the subsequent decrease in their activity was observed in mesophyll durring the first stage of adaptation to salt influence. In bundle sheath cells such parameters are differed from control less essentially. Fast accumulation of piruvate in cells and malate in both investigated tissues was induced. The further salinity led to falling of concentration this intermediate. The concentration of piruvate was below control level, and it was raised by the end of an exposition.The results show that sodium chloride causes induction of Krebs-cycle in mesophyll and bundle sheath cells of corn and intensification of Hatch-Slack cycle. The described differences in function malatdehydrogenase systems of mesophyll and bundle sheath cells of leaves of corn under salinity mainly consist of the activity of enzymes of a studied complex in bundle sheath cells is subject to the minimal changes in comparison with mesophyll. Role of this enzymesystem in mechanisms of adaptive reaction of various tissues of corn to salt stress is discussed.

  3. Protein methylation in pea chloroplasts

    Niemi, K.J.; Adler, J.; Selman, B.R.

    1990-01-01

    The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with [ 3 H-methyl]-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. One methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile [ 3 H]methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the [ 3 H]methyl group

  4. The different fates of mitochondria and chloroplasts during dark-induced senescence in Arabidopsis leaves.

    Keech, Olivier; Pesquet, Edouard; Ahad, Abdul; Askne, Anna; Nordvall, Dag; Vodnala, Sharvani Munender; Tuominen, Hannele; Hurry, Vaughan; Dizengremel, Pierre; Gardeström, Per

    2007-12-01

    Senescence is an active process allowing the reallocation of valuable nutrients from the senescing organ towards storage and/or growing tissues. Using Arabidopsis thaliana leaves from both whole darkened plants (DPs) and individually darkened leaves (IDLs), we investigated the fate of mitochondria and chloroplasts during dark-induced leaf senescence. Combining in vivo visualization of fates of the two organelles by three-dimensional reconstructions of abaxial parts of leaves with functional measurements of photosynthesis and respiration, we showed that the two experimental systems displayed major differences during 6 d of dark treatment. In whole DPs, organelles were largely retained in both epidermal and mesophyll cells. However, while the photosynthetic capacity was maintained, the capacity of mitochondrial respiration decreased. In contrast, IDLs showed a rapid decline in photosynthetic capacity while maintaining a high capacity for mitochondrial respiration throughout the treatment. In addition, we noticed an unequal degradation of organelles in the different cell types of the senescing leaf. From these data, we suggest that metabolism in leaves of the whole DPs enters a 'stand-by mode' to preserve the photosynthetic machinery for as long as possible. However, in IDLs, mitochondria actively provide energy and carbon skeletons for the degradation of cell constituents, facilitating the retrieval of nutrients. Finally, the heterogeneity of the degradation processes involved during senescence is discussed with regard to the fate of mitochondria and chloroplasts in the different cell types.

  5. Characterization of a light-controlled anion channel in the plasma membrane of mesophyll cells of pea

    Elzenga, J.T.M.; Volkenburgh Van, E

    In leaf mesophyll cells of pea (Pisum sativum) light induces a transient depolarization that is at least partly due to an increased plasma membrane conductance for anions. Several channel types were identified in the plasma membrane of protoplasts from mesophyll cells using the patch-clamp

  6. On the structure of the spinach chloroplast

    Thomas, J.B.; Bustraan, M.; Paris, C.H.

    1952-01-01

    The structure of spinach chloroplasts was investigated with the aid of the electron microscope. It has been established that: 1. 1. the outer membrane of the chloroplasts is composed of both proteins and lipoids. 2. 2. the stroma is also built up by these components. 3. 3. within the

  7. Crude oil market report

    1985-01-01

    Falling demand for refined products and an excess of production capacity are driving world oil prices down further. Competitive price cutting, notably by Mexico, Britain, and the Soviet Union, has left Saudi Arabia the only guardian of a costly pricing discipline in terms of crude oil sales. The current crisis is limited to the producers of crude oil. Refineries are now deciding what, where, and how to buy crude in order to meet the requirements of a slack market place. Saudi Arabia could precipitate a price collapse below $20 per barrel by increasing production volume, but that seems unlikely. 1 figure, 2 tables.

  8. Crude oil burning mechanisms

    van Gelderen, Laurens; Malmquist, L.M.V.; Jomaas, Grunde

    2015-01-01

    In order to improve predictions for the burning efficiency and the residue composition of in-situ burning of crude oil, the burning mechanism of crude oil was studied in relation to the composition of its hydrocarbon mixture, before, during and after the burning. The surface temperature, flame...... height, mass loss rate and residues of three hydrocarbon liquids (n-octane, dodecane and hexadecane), two crude oils (DUC and REBCO) and one hydrocarbon liquid mixture of the aforementioned hydrocarbon liquids were studied using the Crude Oil Flammability Apparatus. The experimental results were compared...... on the highest achievable oil slick temperature. Based on this mechanism, predictions can then be made depending on the hydrocarbon composition of the fuel and the measured surface temperature....

  9. Physiological implications of seasonal variation in membrane-associated calcium in red spruce mesophyll cells

    D.H. DeHayes; P.G. Schaberg; G.J. Hawley; C.H. Borer; J.R. Cumming; J.R. Strimbeck

    1997-01-01

    We examined the pattern of seasonal variation in total foliar calcium (Ca) pools and plasma membrane-associated Ca (mCa) in mesophyll cells of current-year and 1-year-old needles of red spruce (Picea rubens Sarg.) and the relationship between mCa and total foliar Ca on an individual plant and seasonal basis. Foliar samples were collected from...

  10. The role of chloroplasts in plant pathology.

    Sowden, Robert G; Watson, Samuel J; Jarvis, Paul

    2018-04-13

    Plants have evolved complex tolerance systems to survive abiotic and biotic stresses. Central to these programmes is a sophisticated conversation of signals between the chloroplast and the nucleus. In this review, we examine the antagonism between abiotic stress tolerance (AST) and immunity: we propose that to generate immunogenic signals, plants must disable AST systems, in particular those that manage reactive oxygen species (ROS), while the pathogen seeks to reactivate or enhance those systems to achieve virulence. By boosting host systems of AST, pathogens trick the plant into suppressing chloroplast immunogenic signals and steer the host into making an inappropriate immune response. Pathogens disrupt chloroplast function, both transcriptionally-by secreting effectors that alter host gene expression by interacting with defence-related kinase cascades, with transcription factors, or with promoters themselves-and post-transcriptionally, by delivering effectors that enter the chloroplast or alter the localization of host proteins to change chloroplast activities. These mechanisms reconfigure the chloroplast proteome and chloroplast-originating immunogenic signals in order to promote infection. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  11. Transient foreign gene expression in chloroplasts of cultured tobacco cells after biolistic delivery of chloroplast vectors.

    Daniell, H; Vivekananda, J; Nielsen, B L; Ye, G N; Tewari, K K; Sanford, J C

    1990-01-01

    Expression of chloramphenicol acetyltransferase (cat) by suitable vectors in chloroplasts of cultured tobacco cells, delivered by high-velocity microprojectiles, is reported here. Several chloroplast expression vectors containing bacterial cat genes, placed under the control of either psbA promoter region from pea (pHD series) or rbcL promoter region from maize (pAC series) have been used in this study. In addition, chloroplast expression vectors containing replicon fragments from pea, tobacc...

  12. 1999 Crude oil market outlook

    Cochener, J.

    1998-01-01

    Baseline projection handling of crude oil prices was discussed, based on actual crude oil price trends from 1992 to 1998. Attention was drawn to the lack of correlation between crude oil and natural gas prices. Predictions for crude oil production were extended to the year 2015. As far as the immediate future is concerned the crude oil price for 1999 was predicted to continue to be sluggish due to competitive pressure from refined products at burner tip. tabs., figs

  13. Transient foreign gene expression in chloroplasts of cultured tobacco cells after biolistic delivery of chloroplast vectors.

    Daniell, H; Vivekananda, J; Nielsen, B L; Ye, G N; Tewari, K K; Sanford, J C

    1990-01-01

    Expression of chloramphenicol acetyltransferase (cat) by suitable vectors in chloroplasts of cultured tobacco cells, delivered by high-velocity microprojectiles, is reported here. Several chloroplast expression vectors containing bacterial cat genes, placed under the control of either psbA promoter region from pea (pHD series) or rbcL promoter region from maize (pAC series) have been used in this study. In addition, chloroplast expression vectors containing replicon fragments from pea, tobacco, or maize chloroplast DNA have also been tested for efficiency and duration of cat expression in chloroplasts of tobacco cells. Cultured NT1 tobacco cells collected on filter papers were bombarded with tungsten particles coated with pUC118 (negative control), 35S-CAT (nuclear expression vector), pHD312 (repliconless chloroplast expression vector), and pHD407, pACp18, and pACp19 (chloroplast expression vectors with replicon). Sonic extracts of cells bombarded with pUC118 showed no detectable cat activity in the autoradiograms. Nuclear expression of cat reached two-thirds of the maximal 48 hr after bombardment and the maximal at 72 hr. Cells bombarded with chloroplast expression vectors showed a low level of expression until 48 hr of incubation. A dramatic increase in the expression of cat was observed 24 hr after the addition of fresh medium to cultured cells in samples bombarded with pHD407; the repliconless vector pHD312 showed about 50% of this maximal activity. The expression of nuclear cat and the repliconless chloroplast vector decreased after 72 hr, but a high level of chloroplast cat expression was maintained in cells bombarded with pHD407. Organelle-specific expression of cat in appropriate compartments was checked by introducing various plasmid constructions into tobacco protoplasts by electroporation. Although the nuclear expression vector 35S-CAT showed expression of cat, no activity was observed with any chloroplast vectors.

  14. Signal function of cytokinin 6-benzylaminopurine in the reaction of Triticum aestivum L. mesophyll cells to hyperthermia

    M. M. Musienko

    2014-12-01

    Full Text Available The signaling effect of 6-benzylaminopurine (BAP on leaf mesophyll cells of Triticum aestivum L. under hyperthermic conditions was studied­. It was found that BAP regulated photosynthetic pigment, hydrogen peroxide content and activity of antioxidant enzymes, namely superoxide dismutase, ascorbate peroxidase and catalase under high-temperature conditions. The additive effect of BAP and high temperature on the activation of cell antioxidant systems was demonstrated. BAP regulated reducing processes in mesophyll leaf cells under high-temperature conditions.

  15. REDUCED CHLOROPLAST COVERAGE genes from Arabidopsis thaliana help to establish the size of the chloroplast compartment.

    Larkin, Robert M; Stefano, Giovanni; Ruckle, Michael E; Stavoe, Andrea K; Sinkler, Christopher A; Brandizzi, Federica; Malmstrom, Carolyn M; Osteryoung, Katherine W

    2016-02-23

    Eukaryotic cells require mechanisms to establish the proportion of cellular volume devoted to particular organelles. These mechanisms are poorly understood. From a screen for plastid-to-nucleus signaling mutants in Arabidopsis thaliana, we cloned a mutant allele of a gene that encodes a protein of unknown function that is homologous to two other Arabidopsis genes of unknown function and to FRIENDLY, which was previously shown to promote the normal distribution of mitochondria in Arabidopsis. In contrast to FRIENDLY, these three homologs of FRIENDLY are found only in photosynthetic organisms. Based on these data, we proposed that FRIENDLY expanded into a small gene family to help regulate the energy metabolism of cells that contain both mitochondria and chloroplasts. Indeed, we found that knocking out these genes caused a number of chloroplast phenotypes, including a reduction in the proportion of cellular volume devoted to chloroplasts to 50% of wild type. Thus, we refer to these genes as REDUCED CHLOROPLAST COVERAGE (REC). The size of the chloroplast compartment was reduced most in rec1 mutants. The REC1 protein accumulated in the cytosol and the nucleus. REC1 was excluded from the nucleus when plants were treated with amitrole, which inhibits cell expansion and chloroplast function. We conclude that REC1 is an extraplastidic protein that helps to establish the size of the chloroplast compartment, and that signals derived from cell expansion or chloroplasts may regulate REC1.

  16. Fatty acid synthesis by spinach chloroplasts, 2

    Yamada, Mitsuhiro; Nakamura, Yasunori

    1975-01-01

    By incorporation of 3 H 2 O into the fatty acid chain in the presence of unlabelled precursor, we showed that fatty acids are synthesized from PGA, PEP and pyruvate by intact spinach chloroplasts in the light. 13 C-tracer experiments confirmed that 1-C of pyruvate is decarboxylated and 2-C is incorporated into fatty acids by the chloroplasts. The patterns of fatty acids synthesized from PGA and pyruvate were the same as that from acetate. The highest rate of fatty acid synthesis was reached at the physiological concentration of PGA (3 mM) and pyruvate (1 mM). These results indicate the operation of the following path in the chloroplasts in light: PGA→PEP→pyruvate→acetylCoA→fatty acids. Since citrate and OAA were much less active and malate and glyoxylate were inert as precursors for fatty acid synthesis, PEP or pyruvate carboxylation, citrate lyase reaction and malate synthetase reaction are not involved in the formation of acetylCoA and fatty acids. Since pyruvate was much more effective as a substrate for fatty acid synthesis than lactate, acetaldehyde or acetate, direct decarboxylation path is considered to be the primary path from pyruvate to acetylCoA. The insignificant effect of chloroplast-washing on fatty acid synthesis from PGA and pyruvate indicates that the glycolytic path from PGA to pyruvate is associated with the chloroplasts. Since pyruvate was more effectively incorporated into fatty acids than acetylCoA, it is unlikely that pyruvate decarboxylation to acetylCoA is due to mitochondria contaminating the chloroplast preparation. On the basis of measurements of 3 H 2 O incorporation in the light and dark, the activity of fatty acid synthesis in spincah leaves appears to be shared by the activities in chloroplasts (87%) and other organelles (13%). (author)

  17. Phylogenomic Analysis and Dynamic Evolution of Chloroplast Genomes in Salicaceae

    Yuan Huang

    2017-06-01

    Full Text Available Chloroplast genomes of plants are highly conserved in both gene order and gene content. Analysis of the whole chloroplast genome is known to provide much more informative DNA sites and thus generates high resolution for plant phylogenies. Here, we report the complete chloroplast genomes of three Salix species in family Salicaceae. Phylogeny of Salicaceae inferred from complete chloroplast genomes is generally consistent with previous studies but resolved with higher statistical support. Incongruences of phylogeny, however, are observed in genus Populus, which most likely results from homoplasy. By comparing three Salix chloroplast genomes with the published chloroplast genomes of other Salicaceae species, we demonstrate that the synteny and length of chloroplast genomes in Salicaceae are highly conserved but experienced dynamic evolution among species. We identify seven positively selected chloroplast genes in Salicaceae, which might be related to the adaptive evolution of Salicaceae species. Comparative chloroplast genome analysis within the family also indicates that some chloroplast genes are lost or became pseudogenes, infer that the chloroplast genes horizontally transferred to the nucleus genome. Based on the complete nucleus genome sequences from two Salicaceae species, we remarkably identify that the entire chloroplast genome is indeed transferred and integrated to the nucleus genome in the individual of the reference genome of P. trichocarpa at least once. This observation, along with presence of the large nuclear plastid DNA (NUPTs and NUPTs-containing multiple chloroplast genes in their original order in the chloroplast genome, favors the DNA-mediated hypothesis of organelle to nucleus DNA transfer. Overall, the phylogenomic analysis using chloroplast complete genomes clearly elucidates the phylogeny of Salicaceae. The identification of positively selected chloroplast genes and dynamic chloroplast-to-nucleus gene transfers in

  18. Methods of analyzing crude oil

    Cooks, Robert Graham; Jjunju, Fred Paul Mark; Li, Anyin; Rogan, Iman S.

    2017-08-15

    The invention generally relates to methods of analyzing crude oil. In certain embodiments, methods of the invention involve obtaining a crude oil sample, and subjecting the crude oil sample to mass spectrometry analysis. In certain embodiments, the method is performed without any sample pre-purification steps.

  19. Nitrogen control of chloroplast development: Progress report

    Schmidt, G.W.

    1987-11-01

    A manifestation of nitrogen deficiency in vascular plants and algae is chlorosis, indicating that chloroplast biogenesis can be strongly restricted by direct or indirect effects of nitrogen assimilation products. To define the molecular basis of nitrogen responses we are using Chlamydomonas reinhardtii. Depending on the levels of ammonium, steady-state deficiency conditions are established such that the cellular levels of chlorophylls and xanthophylls are depressed. Chloroplasts in nitrogen-deficient cells contain appreciable levels of carbon assimilation enzyme and thylakoids with high electron transport activities. However, the light harvesting complexes are nearly absent and Photosystem I exhibits unusual characteristics. Studies of rates of protein synthesis by in vivo pulse-chase labeling and levels of RNAs encoded by the chloroplast and nuclear genomes have been initiated: the accumulation of transcripts for the nuclear light-harvesting apoproteins is dramatically altered qualitatively and quantitatively; there is no major effect on chloroplast RNAs but, in general, these are inefficiently utilized for protein synthesis until nitrogen is provided to the cultures. Supplying nitrogen results in an almost immediate release of chloroplast mRNAs from a translational arrest but the stimulation of the accumulation of nuclear transcripts for light-harvesting apoproteins does not occur until after a 1-2 hour lag

  20. Nitrogen control of chloroplast development: Progress report

    Schmidt, G.W.

    1987-11-01

    A manifestation of nitrogen deficiency in vascular plants and algae is chlorosis, indicating that chloroplast biogenesis can be strongly restricted by direct or indirect effects of nitrogen assimilation products. To define the molecular basis of nitrogen responses we are using Chlamydomonas reinhardtii. Depending on the levels of ammonium, steady-state deficiency conditions are established such that the cellular levels of chlorophylls and xanthophylls are depressed. Chloroplasts in nitrogen-deficient cells contain appreciable levels of carbon assimilation enzyme and thylakoids with high electron transport activities. However, the light harvesting complexes are nearly absent and Photosystem I exhibits unusual characteristics. Studies of rates of protein synthesis by in vivo pulse-chase labeling and levels of RNAs encoded by the chloroplast and nuclear genomes have been initiated: the accumulation of transcripts for the nuclear light-harvesting apoproteins is dramatically altered qualitatively and quantitatively; there is no major effect on chloroplast RNAs but, in general, these are inefficiently utilized for protein synthesis until nitrogen is provided to the cultures. Supplying nitrogen results in an almost immediate release of chloroplast mRNAs from a translational arrest but the stimulation of the accumulation of nuclear transcripts for light-harvesting apoproteins does not occur until after a 1-2 hour lag.

  1. Mergers and acquisitions: malaria and the great chloroplast heist.

    McFadden, G I

    2000-01-01

    The origin of the relict chloroplast recently identified in malarial parasites has been mysterious. Several new papers suggest that the parasites obtained their chloroplasts in an ancient endosymbiotic event that also created some major algal groups.

  2. Analyses of charophyte chloroplast genomes help characterize the ancestral chloroplast genome of land plants.

    Civaň, Peter; Foster, Peter G; Embley, Martin T; Séneca, Ana; Cox, Cymon J

    2014-04-01

    Despite the significance of the relationships between embryophytes and their charophyte algal ancestors in deciphering the origin and evolutionary success of land plants, few chloroplast genomes of the charophyte algae have been reconstructed to date. Here, we present new data for three chloroplast genomes of the freshwater charophytes Klebsormidium flaccidum (Klebsormidiophyceae), Mesotaenium endlicherianum (Zygnematophyceae), and Roya anglica (Zygnematophyceae). The chloroplast genome of Klebsormidium has a quadripartite organization with exceptionally large inverted repeat (IR) regions and, uniquely among streptophytes, has lost the rrn5 and rrn4.5 genes from the ribosomal RNA (rRNA) gene cluster operon. The chloroplast genome of Roya differs from other zygnematophycean chloroplasts, including the newly sequenced Mesotaenium, by having a quadripartite structure that is typical of other streptophytes. On the basis of the improbability of the novel gain of IR regions, we infer that the quadripartite structure has likely been lost independently in at least three zygnematophycean lineages, although the absence of the usual rRNA operonic synteny in the IR regions of Roya may indicate their de novo origin. Significantly, all zygnematophycean chloroplast genomes have undergone substantial genomic rearrangement, which may be the result of ancient retroelement activity evidenced by the presence of integrase-like and reverse transcriptase-like elements in the Roya chloroplast genome. Our results corroborate the close phylogenetic relationship between Zygnematophyceae and land plants and identify 89 protein-coding genes and 22 introns present in the chloroplast genome at the time of the evolutionary transition of plants to land, all of which can be found in the chloroplast genomes of extant charophytes.

  3. Protein methylation reactions in intact pea chloroplasts

    Niemi, K.J.

    1989-01-01

    Post-translational protein methylation was investigated in Pisum sativum chloroplasts. Intact pea chloroplasts were incubated with ( 3 H-methyl)-S-adenosylmethionine under various conditions. The chloroplasts were then separated into stromal and thylakoid fractions and analyzed for radioactivity transferred to protein. Light enhanced the magnitude of labeling in both fractions. One thylakoid polypeptide with an apparent molecular mass of 43 kDa was labeled only in the light. Several other thylakoid and stromal proteins were labeled in both light and dark-labeling conditions. Both base-labile methylation, carboxy-methylesters and base-stable groups, N-methylations were found. Further characterization of the methyl-transfer reactions will be presented

  4. The demise of chloroplast DNA in Arabidopsis.

    Rowan, Beth A; Oldenburg, Delene J; Bendich, Arnold J

    2004-09-01

    Although it might be expected that chloroplast DNA (cpDNA) would be stably maintained in mature leaves, we report the surprising observation that cpDNA levels decline during plastid development in Arabidopsis thaliana (Col.) until most of the leaves contain little or no DNA long before the onset of senescence. We measured the cpDNA content in developing cotyledons, rosette leaves, and cauline leaves. The amount of cpDNA per chloroplast decreases as the chloroplasts develop, reaching undetectable levels in mature leaves. In young cauline leaves, most individual molecules of cpDNA are found in complex, branched forms. In expanded cauline leaves, cpDNA is present in smaller branched forms only at the base of the leaf and is virtually absent in the distal part of the leaf. We conclude that photosynthetic activity may persist long after the demise of the cpDNA. Copyright 2004 Springer-Verlag

  5. Utilization of complete chloroplast genomes for phylogenetic studies

    Ramlee, Shairul Izan Binti

    2016-01-01

    Chloroplast DNA sequence polymorphisms are a primary source of data in many plant phylogenetic studies. The chloroplast genome is relatively conserved in its evolution making it an ideal molecule to retain phylogenetic signals. The chloroplast genome is also largely, but not completely, free from

  6. Non radioactive precursor import into chloroplasts

    Lombardo, V.A.; Ottado, J.

    2003-01-01

    Full text: Eukaryotic cells have a subcellular organization based on organelles. Protein transport to these organelles is quantitatively important because the majority of cellular proteins are codified in nuclear genes and then delivered to their final destination. Most of the chloroplast proteins are translated on cytoplasmic ribosomes as larger precursors with an amino terminal transit peptide that is necessary and sufficient to direct the precursor to the chloroplast. Once inside the organelle the transit peptide is cleaved and the mature protein adopts its folded form. In this work we developed a system for the expression and purification of the pea ferredoxin-NADP + reductase precursor (preFNR) for its import into chloroplasts in non radioactive conditions. We constructed a preFNR fused in its carboxy terminus to a 6 histidines peptide (preFNR-6xHis) that allows its identification using a commercial specific antibody. The construction was expressed, purified, processed and precipitated, rendering a soluble and active preFNR-6xHis that was used in binding and import into chloroplasts experiments. The reisolated chloroplasts were analyzed by SDS-PAGE, electro-blotting and revealed by immuno-detection using either colorimetric or chemiluminescent reactive. We performed also import experiments labeling preFNR and preFNR-6xHis with radioactive methionine as controls. We conclude that preFNR-6xHis is bound and imported into chloroplasts as the wild type preFNR and that both colorimetric or chemiluminescent detection methods are useful to avoid the manipulation of radioactive material. (author)

  7. Heavy crude oil and synthetic crude market outlook

    Crandall, G.R.

    1997-01-01

    This presentation included an outline of the international heavy crude supply and demand versus Canadian heavy crude supply and disposition, and pricing outlook for synthetic crudes. Differences among crude oils such as light sweet, light sour, heavy and bitumen were described and illustrated with respect to their gravity, API, percentage of sulphur, metals and nitrogen. Internationally, heavy and sour crude supplies are forecast to increase significantly over the next four years. Discoveries of light sour crude in offshore Gulf of Mexico will provide a major new source of sour crude to U.S. Gulf Coast refineries. Venezuela's supplies of heavy and sour crude are also expected to increase over the next few years. Mexico and Canada have plans to increase their heavy crude production. All of the crudes will be aimed at the U.S. Gulf Coast and Midwest markets. Pentanes and condensates are also expected to increase based on the growing Canadian natural gas production. Diluent demand will also grow to match Canadian heavy crude/bitumen production. U.S. midwest refiners are proposing expansions to allow them to process more Canadian heavy crude oil. At present, only a few refineries are equipped to process significant amounts of synthetic crude. It was suggested that to absorb available heavy and synthetic production, increased penetration into both Canadian and U.S. markets will be required. Some refineries may have to be modified to process heavy and synthetic oil supplies. Heavy oil and synthetic producers may need to develop relationships with refiners such as joint ventures and term supply agreements to secure markets. 2 tabs., 12 figs

  8. A comparison of rice chloroplast genomes

    Tang, Jiabin; Xia, Hong'ai; Cao, Mengliang

    2004-01-01

    Using high quality sequence reads extracted from our whole genome shotgun repository, we assembled two chloroplast genome sequences from two rice (Oryza sativa) varieties, one from 93-11 (a typical indica variety) and the other from PA64S (an indica-like variety with maternal origin of japonica......), which are both parental varieties of the super-hybrid rice, LYP9. Based on the patterns of high sequence coverage, we partitioned chloroplast sequence variations into two classes, intravarietal and intersubspecific polymorphisms. Intravarietal polymorphisms refer to variations within 93-11 or PA64S...

  9. Distinct abscisic acid signaling pathways for modulation of guard cell versus mesophyll cell potassium channels revealed by expression studies in Xenopus laevis oocytes

    Sutton, F.; Paul, S. S.; Wang, X. Q.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    2000-01-01

    Regulation of guard cell ion transport by abscisic acid (ABA) and in particular ABA inhibition of a guard cell inward K(+) current (I(Kin)) is well documented. However, little is known concerning ABA effects on ion transport in other plant cell types. Here we applied patch clamp techniques to mesophyll cell protoplasts of fava bean (Vicia faba cv Long Pod) plants and demonstrated ABA inhibition of an outward K(+) current (I(Kout)). When mesophyll cell protoplast mRNA (mesophyll mRNA) was expressed in Xenopus laevis oocytes, I(Kout) was generated that displayed similar properties to I(Kout) observed from direct analysis of mesophyll cell protoplasts. I(Kout) expressed by mesophyll mRNA-injected oocytes was inhibited by ABA, indicating that the ABA signal transduction pathway observed in mesophyll cells was preserved in the frog oocytes. Co-injection of oocytes with guard cell protoplast mRNA and cRNA for KAT1, an inward K(+) channel expressed in guard cells, resulted in I(Kin) that was similarly inhibited by ABA. However, oocytes co-injected with mesophyll mRNA and KAT1 cRNA produced I(Kin) that was not inhibited by ABA. These results demonstrate that the mesophyll-encoded signaling mechanism could not substitute for the guard cell pathway. These findings indicate that mesophyll cells and guard cells use distinct and different receptor types and/or signal transduction pathways in ABA regulation of K(+) channels.

  10. Record prices [crude oil

    Anon

    2006-01-01

    Crude oil prices climbed to new record levels on fears of a future loss of supplies from Iran as Washington stepped up its efforts to persuade Tehran to abandon its programme to produce nuclear fuel. IPE's December Brent contract set a new record for the exchange by trading at $75.80/bbl on 21st April. On the same day October WTI reached an all-time high of $77.30/bbl on Nymex. US product prices gained as refiners struggled to produce sufficient middle distillate. Alarmed by the rising retail price of gasoline, the US Senate debated a reduction in the already low US tax rate on motor spirit. The House of Representatives passed a measure to prohibit overcharging for petrol, diesel and heating oil, but Democrats rejected a Republican proposal to speed-up the process for approving new refineries. President George W Bush announced a temporary easing of new gasoline and diesel specifications (see 'Focus', March 2006) to allow more fuel to be produced. He also agreed to delay the repayment of some 2.1 mn bbl of crude oil lent to companies after last year's hurricanes from the Strategic Petroleum Reserve. California announced an inquiry into alleged overcharging for fuel by oil companies operating in the state. (author)

  11. The short-term response of Arabidopsis thaliana (C3) and Zea mays (C4) chloroplasts to red and far red light.

    Zienkiewicz, Maksymilian; Drożak, Anna; Wasilewska, Wioleta; Bacławska, Ilona; Przedpełska-Wąsowicz, Ewa; Romanowska, Elżbieta

    2015-12-01

    Light quality has various effects on photochemistry and protein phosphorylation in Zea mays and Arabidopsis thaliana thylakoids due to different degrees of light penetration across leaves and redox status in chloroplasts. The effect of the spectral quality of light (red, R and far red, FR) on the function of thylakoid proteins in Zea mays and Arabidopsis thaliana was investigated. It was concluded that red light stimulates PSII activity in A. thaliana thylakoids and in maize bundle sheath (BS) thylakoids, but not in mesophyll (M) thylakoids. The light quality did not change PSI activity in M thylakoids of maize. FR used after a white light period increased PSI activity significantly in maize BS and only slightly in A. thaliana thylakoids. As shown by blue native (BN)-PAGE followed by SDS-PAGE, proteins were differently phosphorylated in the thylakoids, indicating their different functions. FR light increased dephosphorylation of LHCII proteins in A. thaliana thylakoids, whereas in maize, dephosphorylation did not occur at all. The rate of phosphorylation was higher in maize BS than in M thylakoids. D1 protein phosphorylation increased in maize and decreased in A. thaliana upon irradiation with both R and growth light (white light, W). Light variations did not change the level of proteins in thylakoids. Our data strongly suggest that response to light quality is a species-dependent phenomenon. We concluded that the maize chloroplasts were differently stimulated, probably due to different degrees of light penetration across the leaf and thereby the redox status in the chloroplasts. These acclimation changes induced by light quality are important in the regulation of chloroplast membrane flexibility and thus its function.

  12. Motif analysis unveils the possible co-regulation of chloroplast genes and nuclear genes encoding chloroplast proteins.

    Wang, Ying; Ding, Jun; Daniell, Henry; Hu, Haiyan; Li, Xiaoman

    2012-09-01

    Chloroplasts play critical roles in land plant cells. Despite their importance and the availability of at least 200 sequenced chloroplast genomes, the number of known DNA regulatory sequences in chloroplast genomes are limited. In this paper, we designed computational methods to systematically study putative DNA regulatory sequences in intergenic regions near chloroplast genes in seven plant species and in promoter sequences of nuclear genes in Arabidopsis and rice. We found that -35/-10 elements alone cannot explain the transcriptional regulation of chloroplast genes. We also concluded that there are unlikely motifs shared by intergenic sequences of most of chloroplast genes, indicating that these genes are regulated differently. Finally and surprisingly, we found five conserved motifs, each of which occurs in no more than six chloroplast intergenic sequences, are significantly shared by promoters of nuclear-genes encoding chloroplast proteins. By integrating information from gene function annotation, protein subcellular localization analyses, protein-protein interaction data, and gene expression data, we further showed support of the functionality of these conserved motifs. Our study implies the existence of unknown nuclear-encoded transcription factors that regulate both chloroplast genes and nuclear genes encoding chloroplast protein, which sheds light on the understanding of the transcriptional regulation of chloroplast genes.

  13. Vacuolar Localization of Endoproteinases EP(1) and EP(2) in Barley Mesophyll Cells.

    Thayer, S S; Huffaker, R C

    1984-05-01

    The localization of two previously characterized endoproteinases (EP(1) and EP(2)) that comprise more than 95% of the protease activity in primary Hordeum vulgare L. var Numar leaves was determined. Intact vacuoles released from washed mesophyll protoplasts by gentle osmotic shock and increase in pH, were purified by flotation through a four-step Ficoll gradient. These vacuoles contained endoproteinases that rapidly degraded purified barley ribulose-1,5-bisphosphate carboxylase (RuBPCase) substrate. Breakdown products and extent of digestion of RuBPCase were determined using 12% polyacrylamide-sodium dodecyl sulfate gels. Coomassie brilliant blue- or silver-stained gels were scanned, and the peaks were integrated to provide quantitative information. The characteristics of the vacuolar endoproteinases (e.g. sensitivity to various inhibitors and activators, and the molecular weights of the breakdown products, i.e. peptide maps) closely resembled those of purified EP(1) and partially purified EP(2). It is therefore concluded that EP(1) and EP(2) are localized in the vacuoles of mesophyll cells.

  14. Uptake of /sup 86/Rb/sup +/ into photoautotrophic mesophyll cells of Papaver somniferum

    Kaiser, W.M.; Jeschke, W.D.; Hartung, W.

    1982-06-01

    Uptake of /sup 86/Rb/sup +/, used as a tracer for potassium, into isolated photoautotrophic mesophyll cells of Papaver somniferum was weakly but consistently stimulated in the light. It showed mono-phasic saturation kinetics with a pH optimum of 7.0, a Vsub(max) of 6.7 ..mu..mol mg/sup -1/ Chl x h/sup -1/ and a Ksub(m) of 2.7 mmol l/sup -1/. Different anions as Cl/sup -/, NO/sub 3//sup -/ and PO/sub 4//sup 3 -/ had no effects on /sup 86/Rb/sup +/ uptake. Sodium ions influenced Rb/sup +/-uptake very weakly, indicating a high K/sup +/ -specificity of the mesophyll cell plasmalemma. Fusicoccin stimulated /sup 86/Rb/sup +/ -uptake strongly whereas abscisic acid inhibited uptake only following preincubation for two hours. Nitrite, CCCP and Dio-9 inhibited /sup 86/Rb/sup +/-uptake which gives evidence that this process is dependent on intact pH-gradients within the cells and on ATP-formation.

  15. Evidence for a specific glutamate/H+ cotransport in isolated mesophyll cells

    McCutcheon, S.L.; Bown, A.W.

    1987-01-01

    Mechanically isolated Asparagus sprengeri Regel mesophyll cells were suspended in 1 millimolar CaSO 4 . Immediate alkalinization of the medium occurred on the addition of 1 millimolar concentrations of L-glutamate (Glu) and its analog L-methionine-D,L-sulfoximine (L-MSO). D-Glu and the L isomers of the protein amino acids did not elicit alkalinization. L-Glu dependent alkalinization was transient and acidification resumed after approximately 30 to 45 minutes. At pH 6.0, 5 millimolar L-Glu stimulated initial rates of alkalinization that varied between 1.3 to 4.1 nmol H + /10 6 cells minute. L-Glu dependent alkalinization was saturable, increased with decreasing pH, was inhibited by carbonyl cyanide-p-trichloromethoxyphenyl hydrazone (CCCP), and was not stimulated by light. Uptake of L-[U- 14 C]glutamate increased as the pH decreased from 6.5 to 5.5, and was inhibited by L-MSO. L-Glu had no influence on K + efflux. Although evidence for multiple amino acid/proton cotransport systems has been found in other tissues, the present report indicates that a highly specific L-Glu/proton uptake process is present in Asparagus mesophyll cells

  16. Maglev crude oil pipeline

    Knolle, Ernst G.

    1994-01-01

    This maglev crude oil pipeline consists of two conduits guiding an endless stream of long containers. One conduit carries loaded containers and the other empty returns. The containers are levitated by permanent magnets in repulsion and propelled by stationary linear induction motors. The containers are linked to each other in a manner that allows them, while in continuous motion, to be folded into side by side position at loading and unloading points. This folding causes a speed reduction in proportion to the ratio of container diameter to container length. While in side by side position, containers are opened at their ends to be filled or emptied. Container size and speed are elected to produce a desired carrying capacity.

  17. An organelle-free assay for pea chloroplast Mg-chelatase: Resolution of the activity into soluble and membrane bound fractions

    Walker, C.J.; Weinstein, J.D. (Clemson Univ, SC (United States))

    1991-05-01

    Mg-chelatase, which catalyzes the insertion of magnesium into protoporphyrin, lies at the branchpoint of heme and chlorophyll biosynthesis in chloroplasts. Since magnesium chelation is the first step unique to chlorophyll synthesis, one would expect this step to be highly regulated. However, to date little is known about the enzymology or regulation of Mg-chelatase due mostly to an inability to assay it's activity outside of the intact plastid. Here the authors report the first truly in vitro i.e. organelle-free, assay for Mg-chelatase. Mg-chelatase activity in intact pea chloroplasts which is 3 to 4 fold higher than in cucumber chloroplasts, survived chloroplast lysis and could be fractionated, by centrifugation, into supernatant and pellet components. Both of these fractions were required to reconstitute Mg-chelatase activity and both were inactivated by boiling; indicating that the enzyme is composed of soluble and membrane bound protein(s). The specific activity of the reconstituted system was typically 1 nmol Mg-Deuteroporphyrin/h/mg protein and activity was linear for at least 60 min under our assay conditions. ATP and magnesium were required for Mg-chelatase activity. The soluble component could be fractionated with ammonium sulfate. The product of the reaction was confirmed fluorometrically as the magnesium chelate of the porphyrin substrate. Crude separation of chloroplast membranes into thylakoids and envelopes, suggested that the membrane-bound component of Mg-chelatase is probably located in the envelope.

  18. Canada's crude oil resources : crude oil in our daily lives

    Bott, R.

    2001-10-01

    Created in 1975, the Petroleum Communication Foundation is a not-for-profit organization. The objective of the Foundation is to inform Canadians about the petroleum industry in Canada. It produces educational, fact-based publications and programs, employing a multi-stakeholder review process. The first section of this publication is devoted to crude oil and the benefits that are derived from it. It begins by providing a brief definition of crude oil, then moves to the many uses in our daily lives and the environmental impacts like air pollution, spills, and footprint on the land from exploration and production activities. Section 2 details the many uses of crude oil and identifies the major oil producing regions of Canada. A quick mention is made of non-conventional sources of crude oil. The search for crude oil is the topic of section 3 of the document, providing an overview of the exploration activities, the access rights that must be obtained before gaining access to the resource. The drilling of oil is discussed in section 4. Section 5 deals with issues pertaining to reservoirs within rocks, while section 6 covers the feeding of the refineries, discussing topics from the movement of oil to market to the refining of the crude oil, and the pricing issues. In section 7, the uncertain future is examined with a view of balancing the supply and demand, as crude oil is a non-renewable resource. Supplementary information is provided concerning additional publications published by various organizations and agencies. figs

  19. Direct chloroplast sequencing: comparison of sequencing platforms and analysis tools for whole chloroplast barcoding.

    Marta Brozynska

    Full Text Available Direct sequencing of total plant DNA using next generation sequencing technologies generates a whole chloroplast genome sequence that has the potential to provide a barcode for use in plant and food identification. Advances in DNA sequencing platforms may make this an attractive approach for routine plant identification. The HiSeq (Illumina and Ion Torrent (Life Technology sequencing platforms were used to sequence total DNA from rice to identify polymorphisms in the whole chloroplast genome sequence of a wild rice plant relative to cultivated rice (cv. Nipponbare. Consensus chloroplast sequences were produced by mapping sequence reads to the reference rice chloroplast genome or by de novo assembly and mapping of the resulting contigs to the reference sequence. A total of 122 polymorphisms (SNPs and indels between the wild and cultivated rice chloroplasts were predicted by these different sequencing and analysis methods. Of these, a total of 102 polymorphisms including 90 SNPs were predicted by both platforms. Indels were more variable with different sequencing methods, with almost all discrepancies found in homopolymers. The Ion Torrent platform gave no apparent false SNP but was less reliable for indels. The methods should be suitable for routine barcoding using appropriate combinations of sequencing platform and data analysis.

  20. Chloroplast Signaling Gates Thermotolerance in Arabidopsis

    Patrick J. Dickinson

    2018-02-01

    Full Text Available Temperature is a key environmental variable influencing plant growth and survival. Protection against high temperature stress in eukaryotes is coordinated by heat shock factors (HSFs, transcription factors that activate the expression of protective chaperones such as HEAT SHOCK PROTEIN 70 (HSP70; however, the pathway by which temperature is sensed and integrated with other environmental signals into adaptive responses is not well understood. Plants are exposed to considerable diurnal variation in temperature, and we have found that there is diurnal variation in thermotolerance in Arabidopsis thaliana, with maximal thermotolerance coinciding with higher HSP70 expression during the day. In a forward genetic screen, we identified a key role for the chloroplast in controlling this response, suggesting that light-induced chloroplast signaling plays a key role. Consistent with this, we are able to globally activate binding of HSFA1a to its targets by altering redox status in planta independently of a heat shock.

  1. Stomatal conductance, mesophyll conductance, and trans piration efficiency in relation to leaf anatomy in rice and wheat genotypes under drought

    Ouyang, Wenjing; Struik, Paul C.; Yin, Xinyou; Yang, Jianchang

    2017-01-01

    Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (g s) and mesophyll conductance (g m) and their anatomical determinants were

  2. Mesophyll conductance to CO2 transport estimated by two independent methods: effect of variable CO2 concentration and abscisic acid

    Vrábl, D.; Vašková, M.; Hronková, Marie; Flexas, J.; Šantrůček, Jiří

    2009-01-01

    Roč. 60, č. 8 (2009), s. 2315-2323 ISSN 0022-0957 R&D Projects: GA AV ČR(CZ) IAA601410505 Institutional research plan: CEZ:AV0Z50510513 Keywords : Carbon dioxide * mesophyll conductance * Helianthus annuus Subject RIV: ED - Physiology Impact factor: 4.271, year: 2009

  3. Chloroplast Chaperonin: An Intricate Protein Folding Machine for Photosynthesis

    Qian Zhao

    2018-01-01

    Full Text Available Group I chaperonins are large cylindrical-shaped nano-machines that function as a central hub in the protein quality control system in the bacterial cytosol, mitochondria and chloroplasts. In chloroplasts, proteins newly synthesized by chloroplast ribosomes, unfolded by diverse stresses, or translocated from the cytosol run the risk of aberrant folding and aggregation. The chloroplast chaperonin system assists these proteins in folding into their native states. A widely known protein folded by chloroplast chaperonin is the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco, an enzyme responsible for the fixation of inorganic CO2 into organic carbohydrates during photosynthesis. Chloroplast chaperonin was initially identified as a Rubisco-binding protein. All photosynthetic eucaryotes genomes encode multiple chaperonin genes which can be divided into α and β subtypes. Unlike the homo-oligomeric chaperonins from bacteria and mitochondria, chloroplast chaperonins are more complex and exists as intricate hetero-oligomers containing both subtypes. The Group I chaperonin requires proper interaction with a detachable lid-like co-chaperonin in the presence of ATP and Mg2+ for substrate encapsulation and conformational transition. Besides the typical Cpn10-like co-chaperonin, a unique co-chaperonin consisting of two tandem Cpn10-like domains joined head-to-tail exists in chloroplasts. Since chloroplasts were proposed as sensors to various environmental stresses, this diversified chloroplast chaperonin system has the potential to adapt to complex conditions by accommodating specific substrates or through regulation at both the transcriptional and post-translational levels. In this review, we discuss recent progress on the unique structure and function of the chloroplast chaperonin system based on model organisms Chlamydomonas reinhardtii and Arabidopsis thaliana. Knowledge of the chloroplast chaperonin system may ultimately lead

  4. Macroautophagy and microautophagy in relation to vacuole formation in mesophyll cells of Dendrobium tepals.

    van Doorn, Wouter G; Kirasak, Kanjana; Ketsa, Saichol

    2015-04-01

    Prior to flower opening, mesophyll cells at the vascular bundles of Dendrobium tepals showed a large increase in vacuolar volume, partially at the expense of the cytoplasm. Electron micrographs indicated that this increase in vacuolar volume was mainly due to vacuole fusion. Macroautophagous structures typical of plant cells were observed. Only a small part of the decrease in cytoplasmic volume seemed due to macroautophagy. The vacuoles contained vesicles of various types, including multilamellar bodies. It was not clear if these vacuolar inclusions were due to macroautophagy or microautophagy. Only a single structure was observed of a protruding vacuole, indicating microautophagy. It is concluded that macroautophagy occurs in these cells but its role in vacuole formation seems small, while a possible role of microautophagy in vacuole formation might be hypothesized. Careful labeling of organelle membranes seems required to advance our insight in plant macro- and microautophagy and their roles in vacuole formation. Copyright © 2015 Elsevier GmbH. All rights reserved.

  5. Variability in mesophyll conductance between barley genotypes, and effects on transpiration efficiency and carbon isotope discrimination.

    Barbour, Margaret M; Warren, Charles R; Farquhar, Graham D; Forrester, Guy; Brown, Hamish

    2010-07-01

    Leaf internal, or mesophyll, conductance to CO(2) (g(m)) is a significant and variable limitation of photosynthesis that also affects leaf transpiration efficiency (TE). Genotypic variation in g(m) and the effect of g(m) on TE were assessed in six barley genotypes (four Hordeum vulgare and two H. bulbosum). Significant variation in g(m) was found between genotypes, and was correlated with photosynthetic rate. The genotype with the highest g(m) also had the highest TE and the lowest carbon isotope discrimination as recorded in leaf tissue (Delta(p)). These results suggest g(m) has unexplored potential to provide TE improvement within crop breeding programmes.

  6. Mechanism of protein import across the chloroplast envelope.

    Chen, K; Chen, X; Schnell, D J

    2000-01-01

    The development and maintenance of chloroplasts relies on the contribution of protein subunits from both plastid and nuclear genomes. Most chloroplast proteins are encoded by nuclear genes and are post-translationally imported into the organelle across the double membrane of the chloroplast envelope. Protein import into the chloroplast consists of two essential elements: the specific recognition of the targeting signals (transit sequences) of cytoplasmic preproteins by receptors at the outer envelope membrane and the subsequent translocation of preproteins simultaneously across the double membrane of the envelope. These processes are mediated via the co-ordinate action of protein translocon complexes in the outer (Toc apparatus) and inner (Tic apparatus) envelope membranes.

  7. Complex chloroplast RNA metabolism: just debugging the genetic programme?

    Schmitz-Linneweber Christian

    2008-08-01

    Full Text Available Abstract Background The gene expression system of chloroplasts is far more complex than that of their cyanobacterial progenitor. This gain in complexity affects in particular RNA metabolism, specifically the transcription and maturation of RNA. Mature chloroplast RNA is generated by a plethora of nuclear-encoded proteins acquired or recruited during plant evolution, comprising additional RNA polymerases and sigma factors, and sequence-specific RNA maturation factors promoting RNA splicing, editing, end formation and translatability. Despite years of intensive research, we still lack a comprehensive explanation for this complexity. Results We inspected the available literature and genome databases for information on components of RNA metabolism in land plant chloroplasts. In particular, new inventions of chloroplast-specific mechanisms and the expansion of some gene/protein families detected in land plants lead us to suggest that the primary function of the additional nuclear-encoded components found in chloroplasts is the transgenomic suppression of point mutations, fixation of which occurred due to an enhanced genetic drift exhibited by chloroplast genomes. We further speculate that a fast evolution of transgenomic suppressors occurred after the water-to-land transition of plants. Conclusion Our inspections indicate that several chloroplast-specific mechanisms evolved in land plants to remedy point mutations that occurred after the water-to-land transition. Thus, the complexity of chloroplast gene expression evolved to guarantee the functionality of chloroplast genetic information and may not, with some exceptions, be involved in regulatory functions.

  8. Crude incompatibility problems at heavy crude unit desalter

    Kirmani, Z.; Khurshid, A.; Alam, N.; Gul, S.; Ahmed, N.

    2009-01-01

    Attock Refinery Limited (ARL) is based at Rawalpindi, Pakistan and operates a 40,000 Barrels per Stream Day (BPSD) refinery. The Heavy Crude Unit (HCU) of ARL is a fully integrated two-stage 10,000 BPSD Atmospheric and 5,700 BPSD Vacuum Distillation Unit. A 3-stage desalter designed to reduce salt and BS and W content from 2,000 parts per thousand barrels (PTB) and 2% to less than 5 PTB and 0.1% respectively, is part of HCU. The feedstock is a composite blend of 14 local Heavy Crudes received at the Refinery. Although in the past this desalter had been giving good performance, over the last one year, period since August 2005, at least nine shutdowns of the unit took place due to salt slippage and consequential tube leakages at the overhead Crude-Naphtha vapor Heat Exchanger where partial condensation of naphtha takes place. Final condensation is achieved in trim condenser. High salted water carry-over with the crude caused increased hydrolysis, formation of Hydrochloric acid and increase of tail water chlorides. Salt contents at the outlet of third desalter at times increased up to 400 PTB with 3.2% BS and W during the above mentioned upsets, as compared to normal 5-10 PTB. Fallout from this loss of desalter control was the creation of large quantities of slop due to draining of strong water oil emulsion from the desalters. Individual crudes of the blend were analyzed for affinity of water and emulsion stability. It was observed that 3 of the 14 crudes formed very strong while the remaining crudes formed weak oil water emulsion, which easily separated water from oil in desalter without any operational problem. Study was further narrowed down to one crude evaluation. Alkaline earth metallic naphthenate surfactants were detected and isolated as responsible for the strong water oil and sediments emulsion. The isolated crude was next withdrawn from the Heavy Crude blend. As soon as it was isolated and its ratio in heavy crude tank came down to 0.7 %, the problem began

  9. Durum and bread wheat differ in their ability to retain potassium in leaf mesophyll: implications for salinity stress tolerance.

    Wu, Honghong; Shabala, Lana; Zhou, Meixue; Shabala, Sergey

    2014-10-01

    Understanding the intrinsic mechanisms involved in the differential salinity tolerance between bread wheat and durum wheat is essential for breeding salt-tolerant varieties to cope with the global salinity issue threatening future food supply. In the past, higher salinity tolerance in bread wheat compared with durum wheat has been attributed to its better ability to exclude Na(+) from uptake. Here we show that another mechanism, namely more superior K(+) retention ability in the leaf mesophyll, also contributes to this difference. A strong positive correlation (R(2) > 0.41, P varieties. However, while the above correlation was strong in bread wheat, it was statistically insignificant in durum wheat. Consistent with these findings, a significantly higher relative leaf K(+) content was found in bread wheat than in durum wheat. In contrast to root tissues, the role of voltage-gated K(+) channels in K(+) retention in the wheat mesophyll was relatively small, and non-selective cation channels played a major role in controlling intracellular K(+) homeostasis. Moreover, a significant negative correlation between NaCl-induced mesophyll H(+) flux and mesophyll K(+) retention was found, and interpreted as a compensatory mechanism employed by sensitive varieties to regain K(+) leaked into the apoplast. It is concluded that bread wheat and durum wheat show different strategies of coping with salinity, and that targeting mechanisms conferring K(+) retention in the leaf mesophyll may be a promising way to improve the overall salinity tolerance in these species. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Expression of Trichoderma reesei β-mannanase in tobacco chloroplasts and its utilization in lignocellulosic woody biomass hydrolysis.

    Pankaj Agrawal

    Full Text Available Lignocellulosic ethanol offers a promising alternative to conventional fossil fuels. One among the major limitations in the lignocellulosic biomass hydrolysis is unavailability of efficient and environmentally biomass degrading technologies. Plant-based production of these enzymes on large scale offers a cost-effective solution. Cellulases, hemicellulases including mannanases and other accessory enzymes are required for conversion of lignocellulosic biomass into fermentable sugars. β-mannanase catalyzes endo-hydrolysis of the mannan backbone, a major constituent of woody biomass. In this study, the man1 gene encoding β-mannanase was isolated from Trichoderma reesei and expressed via the chloroplast genome. PCR and Southern hybridization analysis confirmed site-specific transgene integration into the tobacco chloroplast genomes and homoplasmy. Transplastomic plants were fertile and set viable seeds. Germination of seeds in the selection medium showed inheritance of transgenes into the progeny without any Mendelian segregation. Expression of endo-β-mannanase for the first time in plants facilitated its characterization for use in enhanced lignocellulosic biomass hydrolysis. Gel diffusion assay for endo-β-mannanase showed the zone of clearance confirming functionality of chloroplast-derived mannanase. Endo-β-mannanase expression levels reached up to 25 units per gram of leaf (fresh weight. Chloroplast-derived mannanase had higher temperature stability (40 °C to 70 °C and wider pH optima (pH 3.0 to 7.0 than E.coli enzyme extracts. Plant crude extracts showed 6-7 fold higher enzyme activity than E.coli extracts due to the formation of disulfide bonds in chloroplasts, thereby facilitating their direct utilization in enzyme cocktails without any purification. Chloroplast-derived mannanase when added to the enzyme cocktail containing a combination of different plant-derived enzymes yielded 20% more glucose equivalents from pinewood than the

  11. A Canadian refiner's perspective of synthetic crudes

    Halford, T.L.; McIntosh, A.P.; Rasmussen

    1997-01-01

    Some of the factors affecting a refiner's choice of crude oil include refinery hardware, particularly gas oil crackers, products slate and product specifications, crude availability, relative crude price and crude quality. An overview of synthetic crude, the use of synthetic crude combined with other crudes and a comparison of synthetic crude with conventional crude oil was given. The two main users of synthetic crude are basically two groups of refiners, those large groups who use synthetic crude combined with other crudes, and a smaller group who run synthetic crude on specially designed units as a sole feed. The effects of changes in fuel legislation were reviewed. It was predicted that the changes will have a mixed impact on the value of synthetic crude, but low sulphur diesel regulations and gasoline sulphur regulations will make current synthetic crudes attractive. The big future change with a negative impact will be diesel cetane increases to reduce engine emissions. This will reduce synthetic crude attractiveness due to distillate yields and quality and high gas oil yields. Similarly, any legislation limiting aromatics in diesel fuel will also make synthetic crudes less attractive. Problems experienced by refiners with hardware dedicated to synthetic crude (salt, naphthenic acid, fouling, quality variations) were also reviewed. 3 tabs

  12. Exports of crude oil, 1988

    1989-06-01

    Effective June 1, 1985, licensing and charging of oil exports ended. The Board now issues export orders specifying neither volumes nor prices and covering an exportation period of up to 1 year for light crude oil and up to 2 years for heavy crude oil, available on request to both Canadian and foreign companies. The Board has assumed a monitoring role, and export prices and volumes are reported monthly by exporters. This annual report provides a review of the volumes and prices associated with the supply and disposition of Canadian crude oil during 1988. Highlights are given with detailed information on prices, both internationally, in Canada, and the Chicago posted price by light or heavy crude, and on volumes including capacity and disposition in both domestic and export markets. A short description of the import market is included. Comparisons are made with the previous year. Export volumes of light crude oil in 1988 increased by 13% to average 50,200 m 3 /d. Export volumes of heavy crude also increased by ca 13% to 62,600 m 3 /d. 15 figs., 2 tabs

  13. Market potential for Canadian crude oil

    Heath, M.; Fisher, L.; Golosinski, D.; Luthin, A.; Gill, L.; Raggett, C.

    1997-01-01

    Future key markets for Canadian crude were evaluated, and probable flow volumes and prices were identified. Key concerns of market participants such as pricing, alternative crude sources, pipeline tariffs and crude quality, were examined. An overview of the competition faced by Canadian crude supply in global markets was presented. World crude oil supply and demand was discussed. US and Canadian crude oil supply (2000 to 2010), refinery demand for light and heavy crudes, existing future crude oil and refined product pipeline infrastructure, and pricing implications of changing crude oil flows were analyzed. The general conclusion was that the US market will continue to provide growing markets for Canadian crude oil, and that the Canadian supply to fulfill increased export requirements will be available due to the combined effects of increasing heavy crude supply, growing production from the east coast offshore, and recent and ongoing pipeline expansions and additions. 20 refs., 64 tabs., 42 figs

  14. Orientation of the pigment molecules in the chloroplast

    Goedheer, J.C.

    1955-01-01

    Dichroism, absorption anisotropy, and anomal dispersion of birefringence were measured in the big lamellate chloroplasts of Mougeotia. The results of these measurements indicate a certain orientation of the chlorophyll molecules, and to a smaller extent, of the carotenoids in the chloroplast. In

  15. Comparative studies on codon usage pattern of chloroplasts and ...

    Unknown

    different genomic organization and mutation pressures in nuclear and chloroplast genes. The results of Nc-plots and neutrality plots ... As an important organelle of plants, the chloroplast has its own genomic environment and ... leading to the suggestion that the translation mechanism and patterns of codon usage in ...

  16. Effects of deoxynivalenol on content of chloroplast pigments in barley leaf tissues.

    Bushnell, W R; Perkins-Veazie, P; Russo, V M; Collins, J; Seeland, T M

    2010-01-01

    To understand further the role of deoxynivalenol (DON) in development of Fusarium head blight (FHB), we investigated effects of the toxin on uninfected barley tissues. Leaf segments, 1 to 1.2 cm long, partially stripped of epidermis were floated with exposed mesophyll in contact with DON solutions. In initial experiments with the leaf segments incubated in light, DON at 30 to 90 ppm turned portions of stripped tissues white after 48 to 96 h. The bleaching effect was greatly enhanced by addition of 1 to 10 mM Ca(2+), so that DON at 10 to 30 ppm turned virtually all stripped tissues white within 48 h. Content of chlorophylls a and b and of total carotenoid pigment was reduced. Loss of electrolytes and uptake of Evans blue indicated that DON had a toxic effect, damaging plasmalemmas in treated tissues before chloroplasts began to lose pigment. When incubated in the dark, leaf segments also lost electrolytes, indicating DON was toxic although the tissues remained green. Thus, loss of chlorophyll in light was due to photobleaching and was a secondary effect of DON, not required for toxicity. In contrast to bleaching effects, some DON treatments that were not toxic kept tissues green without bleaching or other signs of injury, indicating senescence was delayed compared with slow yellowing of untreated leaf segments. Cycloheximide, which like DON, inhibits protein synthesis, also bleached some tissues and delayed senescence of others. Thus, the effects of DON probably relate to its ability to inhibit protein synthesis. With respect to FHB, the results suggest DON may have multiple roles in host cells of infected head tissues, including delayed senescence in early stages of infection and contributing to bleaching and death of cells in later stages.

  17. Carbon dioxide fixation in isolated Kalanchoe chloroplasts

    Levi, C.; Gibbs, M.

    1975-07-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 ..mu..moles of CO/sub 2/ per milligram of chlorophyll per hour. The dark rate of fixation was about 1 percent of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1, 6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO/sub 2/ fixation were primarily those of the photosynthetic carbon reduction cycle. (auth)

  18. Regulation of Chloroplastic Carbonic Anhydrase 1

    Porter, Michael A.; Grodzinski, Bernard

    1983-01-01

    It was previously reported that magnesium ion inhibited carbonic anhydrase (Bamberger and Avron 1975 Plant Physiol 56: 481-485). Studies with partially purified carbonic anhydrase from spinach (Spinacia oleracea L.) chloroplasts show that the effect was the result of the chloride counterion and not the magnesium ion. Enzyme activity was reduced 50% upon addition of 3 to 10 millimolar MgCl2 or KCl while all additions of MgSO4 between 0.3 and 10 millimolar were mildly stimulatory. PMID:16663052

  19. A protocol for expression of foreign genes in chloroplasts.

    Verma, Dheeraj; Samson, Nalapalli P; Koya, Vijay; Daniell, Henry

    2008-01-01

    Several major costs associated with the production of biopharmaceuticals or vaccines in fermentation-based systems could be minimized by using plant chloroplasts as bioreactors, which facilitates rapid scale-up. Oral delivery of chloroplast-derived therapeutic proteins through plant cells eliminates expensive purification steps, low temperature storage, transportation and sterile injections for their delivery. Chloroplast transformation technology (CTT) has also been successfully used to engineer valuable agronomic traits and for the production of industrial enzymes and biomaterials. Here, we provide a detailed protocol for the construction of chloroplast expression and integration vectors, selection and regeneration of transformants, evaluation of transgene integration and inheritance, confirmation of transgene expression and extraction, and quantitation and purification of foreign proteins. Integration of appropriate transgenes into chloroplast genomes and the resulting high levels of functional protein expression can be achieved in approximately 6 months in lettuce and tobacco. CTT is eco-friendly because transgenes are maternally inherited in most crop plants.

  20. The complete chloroplast genome of the Dendrobium strongylanthum (Orchidaceae: Epidendroideae).

    Li, Jing; Chen, Chen; Wang, Zhe-Zhi

    2016-07-01

    Complete chloroplast genome sequence is very useful for studying the phylogenetic and evolution of species. In this study, the complete chloroplast genome of Dendrobium strongylanthum was constructed from whole-genome Illumina sequencing data. The chloroplast genome is 153 058 bp in length with 37.6% GC content and consists of two inverted repeats (IRs) of 26 316 bp. The IR regions are separated by large single-copy region (LSC, 85 836 bp) and small single-copy (SSC, 14 590 bp) region. A total of 130 chloroplast genes were successfully annotated, including 84 protein coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analyses showed that the chloroplast genome of Dendrobium strongylanthum is related to that of the Dendrobium officinal.

  1. 15 CFR 754.2 - Crude oil.

    2010-01-01

    ... processed through a crude oil distillation tower. Included are reconstituted crude petroleum, and lease... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Crude oil. 754.2 Section 754.2....2 Crude oil. (a) License requirement. As indicated by the SS notation in the “License Requirements...

  2. Effect of Hf on the fine structure of mesophyll cells from Glycine max, Merr

    Wei, L.; Miller, G.W.

    1972-04-01

    A series of ultrastructural changes were observed in soybean leaves fumigated with 40 to 50 ppb of hydrogen fluoride. In the cytoplasm the presence of small vacuoles was the first noticeable initial change. The fragmentation of the vacuolar membrane occurred either simultaneously or followed immediately. Lipid-droplet-like globules and numerous vesicles occurred subsequently in the cytoplasm and increased as the injury became more severe. There was a decrease in polysomes and a detachment of ribosome from the rough endoplasmic reticulum. Free ribosome concentration also decreased as the injury became severe. Mitochondrial modifications involving dilation of outer and cristae membranes followed by reduction of both cristae number and matrix electron density and the disappearance of mitochondrial granules were observed in the chlorotic leaves. Electron dense inclusions accumulated in some mitochondria as well. The first noticeable change observed in the chloroplast was the presence of clusters of phytoferritin granules within the stoma after only 2 days of fumigation. Alterations in nuclear structures were observed in later stages of injury. Numerous small electron dense particles were found on various types of membranes in cells of severely chlorotic leaves. They were distributed on outer mitochondrial membranes, endoplasmic reticula, dictyosomes, tonoplasts, plasmalemma, nuclear envelopes, and disintegrating organelles and vesicles, but were never observed on membranes of chloroplasts and microbodies. The presence of fluoride has attracted the attention of many workers primarily in certain industrial areas where the emitted atmospheric fluoride concentrates and is accumulated by plants initiating injury. 6 references.

  3. Effects of water stress on photosynthetic electron transport, photophosphorylation, and metabolite levels of Xanthium strumarium mesophyll cells.

    Sharkey, T D; Badger, M R

    1982-12-01

    Several component processes of photosynthesis were measured in osmotically stressed mesophyll cells of Xanthium strumarium L. The ribulose-1,5-bisphosphate regeneration capacity was reduced by water stress. Photophoshorylation was sensitive to water stress but photosynthetic electron transport was unaffected by water potentials down to-40 bar (-4 MPa). The concentrations of several intermediates of the photosynthetic carbon-reduction cycle remained relatively constant and did not indicate that ATP supply was limiting photosynthesis in the water-stressed cells.

  4. Disruption of stomatal lineage signaling or transcriptional regulators has differential effects on mesophyll development, but maintains coordination of gas exchange.

    Dow, Graham J; Berry, Joseph A; Bergmann, Dominique C

    2017-10-01

    Stomata are simultaneously tasked with permitting the uptake of carbon dioxide for photosynthesis while limiting water loss from the plant. This process is mainly regulated by guard cell control of the stomatal aperture, but recent advancements have highlighted the importance of several genes that control stomatal development. Using targeted genetic manipulations of the stomatal lineage and a combination of gas exchange and microscopy techniques, we show that changes in stomatal development of the epidermal layer lead to coupled changes in the underlying mesophyll tissues. This coordinated response tends to match leaf photosynthetic potential (V cmax ) with gas-exchange capacity (g smax ), and hence the uptake of carbon dioxide for water lost. We found that different genetic regulators systematically altered tissue coordination in separate ways: the transcription factor SPEECHLESS (SPCH) primarily affected leaf size and thickness, whereas peptides in the EPIDERMAL PATTERNING FACTOR (EPF) family altered cell density in the mesophyll. It was also determined that interlayer coordination required the cell-surface receptor TOO MANY MOUTHS (TMM). These results demonstrate that stomata-specific regulators can alter mesophyll properties, which provides insight into how molecular pathways can organize leaf tissues to coordinate gas exchange and suggests new strategies for improving plant water-use efficiency. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  5. Stomatal responses to flooding of the intercellular air spaces suggest a vapor-phase signal between the mesophyll and the guard cells.

    Sibbernsen, Erik; Mott, Keith A

    2010-07-01

    Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50 mm KCl or silicone oil into the intercellular spaces also caused stomata to close, but the response was slower than with distilled water. Epidermis-mesophyll grafts for T. pallida were created by placing the epidermis of one leaf onto the exposed mesophyll of another leaf. Stomata in these grafts opened under light but closed rapidly when water was allowed to wick between epidermis and the mesophyll. When epidermis-mesophyll grafts were constructed with a thin hydrophobic filter between the mesophyll and epidermis stomata responded normally to light and CO(2). These data, when taken together, suggest that the effect of water on stomata is caused partly by dilution of K(+) in the guard cell and partly by the existence of a vapor-phase signal that originates in the mesophyll and causes stomata to open in the light.

  6. Stomatal Responses to Flooding of the Intercellular Air Spaces Suggest a Vapor-Phase Signal Between the Mesophyll and the Guard Cells1[OA

    Sibbernsen, Erik; Mott, Keith A.

    2010-01-01

    Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50 mm KCl or silicone oil into the intercellular spaces also caused stomata to close, but the response was slower than with distilled water. Epidermis-mesophyll grafts for T. pallida were created by placing the epidermis of one leaf onto the exposed mesophyll of another leaf. Stomata in these grafts opened under light but closed rapidly when water was allowed to wick between epidermis and the mesophyll. When epidermis-mesophyll grafts were constructed with a thin hydrophobic filter between the mesophyll and epidermis stomata responded normally to light and CO2. These data, when taken together, suggest that the effect of water on stomata is caused partly by dilution of K+ in the guard cell and partly by the existence of a vapor-phase signal that originates in the mesophyll and causes stomata to open in the light. PMID:20472750

  7. Chloroplasts in anther endothecium of Zea mays (Poaceae).

    Murphy, Katherine M; Egger, Rachel L; Walbot, Virginia

    2015-11-01

    Although anthers of Zea mays, Oryza sativa, and Arabidopsis thaliana have been studied intensively using genetic and biochemical analyses in the past 20 years, few updates to anther anatomical and ultrastructural descriptions have been reported. For example, no transmission electron microscopy (TEM) images of the premeiotic maize anther have been published. Here we report the presence of chloroplasts in maize anthers. TEM imaging, electron acceptor photosynthesis assay, in planta photon detection, microarray analysis, and light and fluorescence microscopy were used to investigate the presence of chloroplasts in the maize anther. Most cells of the maize subepidermal endothecium have starch-containing chloroplasts that do not conduct measurable photosynthesis in vitro. The maize anther contains chloroplasts in most subepidermal, endothecial cells. Although maize anthers receive sufficient light to photosynthesize in vivo and the maize anther transcribes >96% of photosynthesis-associated genes found in the maize leaf, no photosynthetic light reaction activity was detected in vitro. The endothecial cell layer should no longer be defined as a complete circle viewed transversely in anther lobes, because chloroplasts are observed only in cells directly beneath the epidermis and not those adjacent to the connective tissue. We propose that chloroplasts be a defining characteristic of differentiated endothecial cells and that nonsubepidermal endothecial cells that lack chloroplasts be defined as a separate cell type, the interendothecium. © 2015 Botanical Society of America.

  8. Development of Chloroplast Genomic Resources in Chinese Yam (Dioscorea polystachya

    Junling Cao

    2018-01-01

    Full Text Available Chinese yam has been used both as a food and in traditional herbal medicine. Developing more effective genetic markers in this species is necessary to assess its genetic diversity and perform cultivar identification. In this study, new chloroplast genomic resources were developed using whole chloroplast genomes from six genotypes originating from different geographical locations. The Dioscorea polystachya chloroplast genome is a circular molecule consisting of two single-copy regions separated by a pair of inverted repeats. Comparative analyses of six D. polystachya chloroplast genomes revealed 141 single nucleotide polymorphisms (SNPs. Seventy simple sequence repeats (SSRs were found in the six genotypes, including 24 polymorphic SSRs. Forty-three common indels and five small inversions were detected. Phylogenetic analysis based on the complete chloroplast genome provided the best resolution among the genotypes. Our evaluation of chloroplast genome resources among these genotypes led us to consider the complete chloroplast genome sequence of D. polystachya as a source of reliable and valuable molecular markers for revealing biogeographical structure and the extent of genetic variation in wild populations and for identifying different cultivars.

  9. Global RNA association with the transcriptionally active chromosome of chloroplasts.

    Lehniger, Marie-Kristin; Finster, Sabrina; Melonek, Joanna; Oetke, Svenja; Krupinska, Karin; Schmitz-Linneweber, Christian

    2017-10-01

    Processed chloroplast RNAs are co-enriched with preparations of the chloroplast transcriptionally active chromosome. Chloroplast genomes are organized as a polyploid DNA-protein structure called the nucleoid. Transcriptionally active chloroplast DNA together with tightly bound protein factors can be purified by gel filtration as a functional entity called the transcriptionally active chromosome (TAC). Previous proteomics analyses of nucleoids and of TACs demonstrated a considerable overlap in protein composition including RNA binding proteins. Therefore the RNA content of TAC preparations from Nicotiana tabacum was determined using whole genome tiling arrays. A large number of chloroplast RNAs was found to be associated with the TAC. The pattern of RNAs attached to the TAC consists of RNAs produced by different chloroplast RNA polymerases and differs from the pattern of RNA found in input controls. An analysis of RNA splicing and RNA editing of selected RNA species demonstrated that TAC-associated RNAs are processed to a similar extent as the RNA in input controls. Thus, TAC fractions contain a specific subset of the processed chloroplast transcriptome.

  10. Crude oil pipeline expansion summary

    2005-02-01

    The Canadian Association of Petroleum Producers has been working with producers to address issues associated with the development of new pipeline capacity from western Canada. This document presents an assessment of the need for additional oil pipeline capacity given the changing mix of crude oil types and forecasted supply growth. It is of particular interest to crude oil producers and contributes to current available information for market participants. While detailed, the underlying analysis does not account for all the factors that may come into play when individual market participants make choices about which expansions they may support. The key focus is on the importance of timely expansion. It was emphasized that if pipeline expansions lags the crude supply growth, then the consequences would be both significant and unacceptable. Obstacles to timely expansion are also discussed. The report reviews the production and supply forecasts, the existing crude oil pipeline infrastructure, opportunities for new market development, requirements for new pipeline capacity and tolling options for pipeline development. tabs., figs., 1 appendix

  11. Mercury in Canadian crude oil

    Hollebone, B.P.

    2005-01-01

    Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

  12. Crude value management through pipeline systems

    Segato, R. [Suncor Energy Marketing Inc., Calgary, AB (Canada)

    2009-07-01

    This presentation reviewed Suncor's integrated oil flow operations with particular focus on the best practices in crude oil quality management from source rocks to refineries. Suncor produces synthetic crude at its operations in Fort McMurray, Alberta. The crude reaches destinations across North America. The quality of injected and delivered crude varies because of pipeline and terminal logistics, which implies changes in valuation. Refinery planners, engineers and crude traders are faced with the challenge of maximizing profitability while minimizing risk. Refiners face a continuously changing landscape in terms of crude classifications, new commodity developments, batch interferences, shared tank bottoms and sampling limitations. tabs., figs.

  13. Complete chloroplast genome of Gracilaria firma (Gracilariaceae, Rhodophyta), with discussion on the use of chloroplast phylogenomics in the subclass Rhodymeniophycidae.

    Ng, Poh-Kheng; Lin, Showe-Mei; Lim, Phaik-Eem; Liu, Li-Chia; Chen, Chien-Ming; Pai, Tun-Wen

    2017-01-06

    The chloroplast genome of Gracilaria firma was sequenced in view of its role as an economically important marine crop with wide industrial applications. To date, there are only 15 chloroplast genomes published for the Florideophyceae. Apart from presenting the complete chloroplast genome of G. firma, this study also assessed the utility of genome-scale data to address the phylogenetic relationships within the subclass Rhodymeniophycidae. The synteny and genome structure of the chloroplast genomes across the taxa of Eurhodophytina was also examined. The chloroplast genome of Gracilaria firma maps as a circular molecule of 187,001 bp and contains 252 genes, which are distributed on both strands and consist of 35 RNA genes (3 rRNAs, 30 tRNAs, tmRNA and a ribonuclease P RNA component) and 217 protein-coding genes, including the unidentified open reading frames. The chloroplast genome of G. firma is by far the largest reported for Gracilariaceae, featuring a unique intergenic region of about 7000 bp with discontinuous vestiges of red algal plasmid DNA sequences interspersed between the nblA and cpeB genes. This chloroplast genome shows similar gene content and order to other Florideophycean taxa. Phylogenomic analyses based on the concatenated amino acid sequences of 146 protein-coding genes confirmed the monophyly of the classes Bangiophyceae and Florideophyceae with full nodal support. Relationships within the subclass Rhodymeniophycidae in Florideophyceae received moderate to strong nodal support, and the monotypic family of Gracilariales were resolved with maximum support. Chloroplast genomes hold substantial information that can be tapped for resolving the phylogenetic relationships of difficult regions in the Rhodymeniophycidae, which are perceived to have experienced rapid radiation and thus received low nodal support, as exemplified in this study. The present study shows that chloroplast genome of G. firma could serve as a key link to the full resolution of

  14. Inorganic carbon uptake during photosynthesis. II. Uptake by isolated Asparagus mesophyll cells during isotopic disequilibrium

    Espie, G.S.; Owttrim, G.W.; Colman, B.

    1986-01-01

    The species of inorganic carbon (CO 2 or HCO 3 - ) taken up as a source of substrate for photosynthetic fixation by isolated Asparagus sprengeri mesophyll cells is investigated. Discrimination between CO 2 or HCO 3 - transport, during steady state photosynthesis, is achieved by monitoring the changes (by 14 C fixation) which occur in the specific activity of the intracellular pool of inorganic carbon when the inorganic carbon present in the suspending medium is in a state of isotopic disequilibrium. Quantitative comparisons between theoretical (CO 2 or HCO 3 - transport) and experimental time-courses of 14 C incorporation, over the pH range of 5.2 to 7.5, indicate that the specific activity of extracellular CO 2 , rather than HCO 3 - , is the appropriate predictor of the intracellular specific activity. It is concluded, therefore, that CO 2 is the major source of exogenous inorganic carbon taken up by Asparagus cells. However, at high pH (8.5), a component of net DIC uptake may be attributable to HCO 3 - transport, as the incorporation of 14 C during isotopic disequilibrium exceeds the maximum possible incorporation predicted on the basis of CO 2 uptake alone. The contribution of HCO 3 - to net inorganic carbon uptake (pH 8.5) is variable, ranging from 5 to 16%, but is independent of the extracellular HCO 3 - concentration. The evidence for direct HCO 3 - transport is subject to alternative explanations and must, therefore, be regarded as equivocal. Nonlinear regression analysis of the rate of 14 C incorporation as a function of time indicates the presence of a small extracellular resistance to the diffusion of CO 2 , which is partially alleviated by a high extracellular concentration of HCO 3 -

  15. Separation of Chloroplast Pigments Using Reverse Phase Chromatography.

    Reese, R. Neil

    1997-01-01

    Presents a protocol that uses reverse phase chromatography for the separation of chloroplast pigments. Provides a simple and relatively safe procedure for use in teaching laboratories. Discusses pigment extraction, chromatography, results, and advantages of the process. (JRH)

  16. Transport of Ions Across the Inner Envelope Membrane of Chloroplasts

    McCarty, R. E.

    2004-01-01

    The technical report outlines the results of nine years of research on how ions cross the inner envelope membrane of chloroplasts. The ions include protons, nitrite, calcium and ferrous iron. Bicarbonate transport was also studied

  17. Biodegradation of chlorobenzene using immobilized crude extracts ...

    SERVER

    2007-10-04

    Oct 4, 2007 ... immobilized crude extracts were reused for all other experiments and found that immobilization .... India which are of analytical reagent grade. .... 9. 60. 3. 1. Figure 3. Degradation of chlorobenzene by immobilized crude.

  18. Inhibition of chloroplast protein synthesis following light chilling of tomato

    Kent, J.; Ort, D.

    1989-01-01

    In the present study we looked at the effects of a high light chill on the pulsed incorporation of 35 S methionine into total, stromal, and thylakoid proteins of lightly abraded leaflets of 18-21 day old tomato (Lycopersicon esculentum Mill ca. Floramerica) seedlings. Based on gel fluorographic patterns of marker proteins that are indicative of the net rates of chloroplast and cytoplasmic protein synthesis, there appears to be a nearly complete cessation of chloroplastic protein synthesis. No labeling is observed for either the stromal large subunit of Rubisco or the thylakoid-bound alpha and beta subunits of the coupling factor. One notable exception, however, appears to be the 32 kd, D1 protein. Its net synthetic rate remains high despite the inhibition of other chloroplastically synthesized proteins. The small subunit of Rubicso, LHCP-II, as well as several other proteins of known cytoplasmic origin, were still synthesized, albeit, at lower than control rates. Light chilling of chill-insensitive spinach produced a similar, but less dramatic differential behavior between chloroplastic and cytoplasmic protein synthesis. It appears, in chilling-sensitive plants, that chloroplast protein synthesis exhibits a greater sensitivity to low temperature inhibition than does cytoplasmic protein synthesis and that recovery of chloroplast protein synthesis may play an important role in recovery of photosynthetic activity following chilling

  19. First crude oil from Chukotka

    Arenbrister, L.P.; Demidenko, K.A.; Zhmykhova, N.M.

    1986-01-01

    The physicochemical properties of the crude taken from Neogene deposits at a depth of 1486-1443 m are analyzed. The oil is distinguished by low contents of sulfur and resinous-asphaltenic substances, a high content of wax, and a high yield of light cuts distilling below 350 degrees C. The naptha cuts have high contents of naphthenes, and the diesel fuel cuts have high cetane numbers, low sulfur contents, and high contents of straight chain paraffins. The vacuum gasoil has a low density, a low viscosity, a low carbon residue and low contents of sulfur and nitrogen. This gasoil is a good feedstock for catalytic cracking and hydrocracking. The Verkhne-Echin crude is classified as light, low-sulfur, lowresin and high-wax. It can be used to produce jet fuels and summer-grade diesel fuels with low sulfur contents, as well as high-V.I. lube base stocks and liquid and solid paraffins.

  20. The price of crude oil

    Bakhtiari, A.M.S.

    1999-01-01

    The price of crude oil is among the most important prices quoted daily across the world - which is not surprising, since crude oil is the most widely used source of energy worldwide, as well as being a unique commodity. When petroleum burst onto the world stage in 1859, its price first went through some initial gyrations (1860-70), before settling in the $1.00 - 2.00 per barrel range (barring a few exceptions) for a full century. Then, the price underwent two 'shocks' (1973 and 1980), followed by the 'counter-shock' of 1986. Thereafter, the price entered the relative stability of the $15 - 20 /b consensus, where it lingered until recently. Some day, there is bound to be a fresh paradigm of 'insufficient oil reserves', thus ushering in a new era for oil prices. Taking into consideration available data on reserves and expert analysis, it would seem that that day may be years rather than decades away

  1. 7 CFR 29.3015 - Crude.

    2010-01-01

    ... of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Crude. A subdegree of maturity. Crude leaves are usually hard and slick as a result of extreme immaturity. A similar condition may result from sunburn or sunscald. Any leaf which is crude to the extent of...

  2. Chloroplast microsatellite markers for Pseudotaxus chienii developed from the whole chloroplast genome of Taxus chinensis var. mairei (Taxaceae).

    Deng, Qi; Zhang, Hanrui; He, Yipeng; Wang, Ting; Su, Yingjuan

    2017-03-01

    Pseudotaxus chienii (Taxaceae) is an old rare species endemic to China that has adapted well to ecological heterogeneity with high genetic diversity in its nuclear genome. However, the genetic variation in its chloroplast genome is unknown. Eighteen chloroplast microsatellite markers (cpSSRs) were developed from the whole chloroplast genome of Taxus chinensis var. mairei and successfully amplified in four P. chienii populations and one T. chinensis var. mairei population. Of these loci, 10 were polymorphic in P. chienii , whereas six were polymorphic in T. chinensis var. mairei . The unbiased haploid diversity per locus ranged from 0.000 to 0.641 and 0.000 to 0.545 for P. chienii and T. chinensis var. mairei , respectively. The 18 cpSSRs will be used to further investigate the chloroplast genetic structure and adaptive evolution in P. chienii populations.

  3. Radiation treatment of crude drugs

    Stock, A.; Gebhardt, G.; Helle, N.; Schuettler, C.; Boegl, K.W.

    1992-01-01

    It may be necessary to reduce microbiological contamination of crude drugs (medicinal plants or their parts like roots, leaves, flowers). This can be done by treating the drugs with ionizing radiation. Meethods for detection of such an irradiation were developed. It could be pointed out that measurements of luminescence, viscosity and electron spin resonance were suitable for specific drugs, but not for all drugs. (orig.) [de

  4. The complete chloroplast genome sequence of Helwingia himalaica (Helwingiaceae, Aquifoliales) and a chloroplast phylogenomic analysis of the Campanulidae

    Yao, Xin; Liu, Ying-Ying; Tan, Yun-Hong; Song, Yu; Corlett, Richard T.

    2016-01-01

    Complete chloroplast genome sequences have been very useful for understanding phylogenetic relationships in angiosperms at the family level and above, but there are currently large gaps in coverage. We report the chloroplast genome for Helwingia himalaica, the first in the distinctive family Helwingiaceae and only the second genus to be sequenced in the order Aquifoliales. We then combine this with 36 published sequences in the large (c. 35,000 species) subclass Campanulidae in order to inves...

  5. Benchmark West Texas Intermediate crude assayed

    Rhodes, A.K.

    1994-01-01

    The paper gives an assay of West Texas Intermediate, one of the world's market crudes. The price of this crude, known as WTI, is followed by market analysts, investors, traders, and industry managers around the world. WTI price is used as a benchmark for pricing all other US crude oils. The 41 degree API < 0.34 wt % sulfur crude is gathered in West Texas and moved to Cushing, Okla., for distribution. The WTI posted prices is the price paid for the crude at the wellhead in West Texas and is the true benchmark on which other US crudes are priced. The spot price is the negotiated price for short-term trades of the crude. And the New York Mercantile Exchange, or Nymex, price is a futures price for barrels delivered at Cushing

  6. Analysis of protein interactions at native chloroplast membranes by ellipsometry.

    Verena Kriechbaumer

    Full Text Available Membrane bound receptors play vital roles in cell signaling, and are the target for many drugs, yet their interactions with ligands are difficult to study by conventional techniques due to the technical difficulty of monitoring these interactions in lipid environments. In particular, the ability to analyse the behaviour of membrane proteins in their native membrane environment is limited. Here, we have developed a quantitative approach to detect specific interactions between low-abundance chaperone receptors within native chloroplast membranes and their soluble chaperone partners. Langmuir-Schaefer film deposition was used to deposit native chloroplasts onto gold-coated glass slides, and interactions between the molecular chaperones Hsp70 and Hsp90 and their receptors in the chloroplast membranes were detected and quantified by total internal reflection ellipsometry (TIRE. We show that native chloroplast membranes deposited on gold-coated glass slides using Langmuir-Schaefer films retain functional receptors capable of binding chaperones with high specificity and affinity. Taking into account the low chaperone receptor abundance in native membranes, these binding properties are consistent with data generated using soluble forms of the chloroplast chaperone receptors, OEP61 and Toc64. Therefore, we conclude that chloroplasts have the capacity to selectively bind chaperones, consistent with the notion that chaperones play an important role in protein targeting to chloroplasts. Importantly, this method of monitoring by TIRE does not require any protein labelling. This novel combination of techniques should be applicable to a wide variety of membranes and membrane protein receptors, thus presenting the opportunity to quantify protein interactions involved in fundamental cellular processes, and to screen for drugs that target membrane proteins.

  7. Thermotolerant and mesophylic fungi from sugarcane bagasse and their prospection for biomass-degrading enzyme production

    Bruna Silveira Lamanes dos Santos

    2015-09-01

    Full Text Available Nineteen fungi and seven yeast strains were isolated from sugarcane bagasse piles from an alcohol plant located at Brazilian Cerrado and identified up to species level on the basis of the gene sequencing of 5.8S-ITS and 26S ribosomal DNA regions. Four species were identified: Kluyveromyces marxianus, Aspergillus niger, Aspergillus sydowii and Aspergillus fumigatus, and the isolates were screened for the production of key enzymes in the saccharification of lignocellulosic material. Among them, three strains were selected as good producers of hemicellulolitic enzymes: A. niger (SBCM3, A. sydowii (SBCM7 and A. fumigatus (SBC4. The best β-xylosidase producer was A. niger SBCM3 strain. This crude enzyme presented optimal activity at pH 3.5 and 55 °C (141 U/g. For β-glucosidase and xylanase the best producer was A. fumigatus SBC4 strain, whose enzymes presented maximum activity at 60 °C and pH 3.5 (54 U/g and 4.0 (573 U/g, respectively. All these crude enzymes presented stability around pH 3.0–8.0 and up to 60 °C, which can be very useful in industrial processes that work at high temperatures and low pHs. These enzymes also exhibited moderate tolerance to ethanol and the sugars glucose and xylose. These similar characteristics among these fungal crude enzymes suggest that they can be used synergistically in cocktails in future studies of biomass conversion with potential application in several biotechnological sectors.

  8. Insights into the Mechanisms of Chloroplast Division

    Yamato Yoshida

    2018-03-01

    Full Text Available The endosymbiosis of a free-living cyanobacterium into an ancestral eukaryote led to the evolution of the chloroplast (plastid more than one billion years ago. Given their independent origins, plastid proliferation is restricted to the binary fission of pre-existing plastids within a cell. In the last 25 years, the structure of the supramolecular machinery regulating plastid division has been discovered, and some of its component proteins identified. More recently, isolated plastid-division machineries have been examined to elucidate their structural and mechanistic details. Furthermore, complex studies have revealed how the plastid-division machinery morphologically transforms during plastid division, and which of its component proteins play a critical role in generating the contractile force. Identifying the three-dimensional structures and putative functional domains of the component proteins has given us hints about the mechanisms driving the machinery. Surprisingly, the mechanisms driving plastid division resemble those of mitochondrial division, indicating that these division machineries likely developed from the same evolutionary origin, providing a key insight into how endosymbiotic organelles were established. These findings have opened new avenues of research into organelle proliferation mechanisms and the evolution of organelles.

  9. Mesophyll conductance in Zea mays responds transiently to CO2 availability: implications for transpiration efficiency in C4 crops.

    Kolbe, Allison R; Cousins, Asaph B

    2018-03-01

    Mesophyll conductance (g m ) describes the movement of CO 2 from the intercellular air spaces below the stomata to the site of initial carboxylation in the mesophyll. In contrast with C 3 -g m , little is currently known about the intraspecific variation in C 4 -g m or its responsiveness to environmental stimuli. To address these questions, g m was measured on five maize (Zea mays) lines in response to CO 2 , employing three different estimates of g m . Each of the methods indicated a significant response of g m to CO 2 . Estimates of g m were similar between methods at ambient and higher CO 2 , but diverged significantly at low partial pressures of CO 2 . These differences are probably driven by incomplete chemical and isotopic equilibrium between CO 2 and bicarbonate under these conditions. Carbonic anhydrase and phosphoenolpyruvate carboxylase in vitro activity varied significantly despite similar values of g m and leaf anatomical traits. These results provide strong support for a CO 2 response of g m in Z. mays, and indicate that g m in maize is probably driven by anatomical constraints rather than by biochemical limitations. The CO 2 response of g m indicates a potential role for facilitated diffusion in C 4 -g m . These results also suggest that water-use efficiency could be enhanced in C 4 species by targeting g m . © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  10. Photosynthetic response of an alpine plant, Rhododendron delavayi Franch, to water stress and recovery: the role of mesophyll conductance

    Yanfei eCai

    2015-12-01

    Full Text Available Rhododendron delavayi Franch is an evergreen shrub or small tree with large scarlet flowers that makes it highly attractive as an ornamental species. The species is native to southwest China and southeast Asia, especially the Himalayan region, showing good adaptability and tolerance to drought. To understand the water stress coping mechanisms of R. delavayi, we analysed the plant’s photosynthetic performance during water stress and recovery. In particular, we looked at the regulation of stomatal (gs and mesophyll conductance (gm, and maximum rate of carboxylation (Vcmax. After four days of water stress treatment, the net CO2 assimilation rate (AN declined slightly while gs and gm were not affected and stomatal limitation (SL was therefore negligible. At this stage mesophyll conductance limitation (MCL and biochemical limitation (BL constituted the main limitation factors. After eight days of water stress treatment, AN, gs and gm had decreased notably. At this stage SL increased markedly and MCL even more so, while BL remained relatively constant. After re-watering, the recovery of AN, gs and gm was rapid, although remaining below the levels of the control plants, while Vcmax fully regained control levels after three days of re-watering. MCL remained the main limitation factor irrespective of the degree of photosynthetic recovery. In conclusion, in our experiment MCL was the main photosynthetic limitation factor of R. delavayi under water stress and during the recovery phase, with the regulation of gm probably being the result of interactions between the environment and leaf anatomical features.

  11. Differential gene expression and transport functionality in the bundle sheath versus mesophyll - a potential role in leaf mineral homeostasis.

    Wigoda, Noa; Pasmanik-Chor, Metsada; Yang, Tianyuan; Yu, Ling; Moshelion, Menachem; Moran, Nava

    2017-06-01

    Under fluctuating ambient conditions, the ability of plants to maintain hydromineral homeostasis requires the tight control of long distance transport. This includes the control of radial transport within leaves, from veins to mesophyll. The bundle sheath is a structure that tightly wraps around leaf vasculature. It has been suggested to act as a selective barrier in the context of radial transport. This suggestion is based on recent physiological transport assays of bundle sheath cells (BSCs), as well as the anatomy of these cells.We hypothesized that the unique transport functionality of BSCs is apparent in their transcriptome. To test this, we compared the transcriptomes of individually hand-picked protoplasts of GFP-labeled BSCs and non-labeled mesophyll cells (MCs) from the leaves of Arabidopsis thaliana. Of the 90 genes differentially expressed between BSCs and MCs, 45% are membrane related and 20% transport related, a prominent example being the proton pump AHA2. Electrophysiological assays showed that the major AKT2-like membrane K+ conductances of BSCs and MCs had different voltage dependency ranges. Taken together, these differences may cause simultaneous but oppositely directed transmembrane K+ fluxes in BSCs and MCs, in otherwise similar conditions. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  12. Anatomia foliar de microtomateiros fitocromo-mutantes e ultra-estrutura de cloroplastos Leaf anatomy of micro-tomato phytochrome-mutants and chloroplast ultra-structure

    Hyrandir Cabral de Melo

    2011-02-01

    Full Text Available Plantas fitocromo-mutantes têm sido utilizadas com o intuito de caracterizar isoladamente, dentre os demais fotorreceptores, a ação dos fitocromos sobre eventos ligados à fotomorfogênese. Raros são os estudos que relatam a ação dos fitocromos sobre aspectos estruturais, embora sejam fundamentais à compreensão do desenvolvimento das plantas. Neste trabalho, objetivou-se analisar características ultraestruturais de cloroplastos e aspectos anatômicos foliares dos microtomateiros (Solanum lycopersicum L. cv. Micro-Tom fitocromo-mutantes aurea (subexpressa fitocromos, hp1 e atroviolacea (ambos supra-responsivos a eventos mediados por fitocromo em plantas em estágio de floração. Observou-se que os fitocromos são responsáveis pela expressão de muitas características anatômicas da epiderme foliar, assim como do mesofilo e da ultraestrutura dos cloroplastos.Phytochrome-mutant plants have been used for phytochrome action characterization among all photoreceptors, in events of photomorphogenesis. Studies relating the phytochrome action on structural aspects, which are fundamental to the comprehension of plant development, are rare. The objective of this work was to analyze chloroplast ultra structure and leaf anatomical characteristics of micro-tomatos (Solanum lycopersicum L. cv. Micro-Tom phytochrome-mutants aurea (sub express phytochrome, hp1 and atroviolacea (both super express phytochrome events-mediated in plants in the flowering stage. The results show that phytochromes are responsible for the expression of many characteristics of leaf epidermis, mesophyll and chloroplast ultra-structure.

  13. Polyuridylylation and processing of transcripts from multiple gene minicircles in chloroplasts of the dinoflagellate Amphidinium carterae

    Barbrook, Adrian C.; Dorrell, Richard G.; Burrows, Jennifer; Plenderleith, Lindsey J.; Nisbet, R. Ellen R.; Howe, Christopher J.

    2012-01-01

    -PCR to study transcription and transcript processing in the chloroplasts of Amphidinium carterae, a model peridinin-containing dinoflagellate. These organisms have a highly unusual chloroplast genome, with genes located on multiple small 'minicircle' elements

  14. OPEC's optimal crude oil price

    Horn, Manfred

    2004-01-01

    OPEC decided to stabilise oil prices within a range of 22-28 US Dollar/barrel of crude oil. Such an oil-price-level is far beyond the short and long run marginal costs of oil production, beyond even that in regions with particularly high costs. Nevertheless, OPEC may achieve its goal if world demand for oil increases substantially in the future and oil resources outside the OPEC are not big enough to accordingly increase production. In this case OPEC, which controls about 78% of world oil reserves, has to supply a large share of that demand increase. If we assume OPEC will behave as a partial monopolist on the oil market, which takes into consideration the reaction of the other producers to its own sales strategy, it can reach its price target. Lower prices before 2020 are probable only if the OPEC cartel breaks up. Higher prices are possible if production outside OPEC is inelastic as assumed by some geologists, but they would probably stimulate the production of unconventional oil based on oil sand or coal. Crude oil prices above 30 US Dollar/barrel are therefore probably not sustainable for a long period. (Author)

  15. Oryza sativa Chloroplast Signal Recognition Particle 43 (OscpSRP43 Is Required for Chloroplast Development and Photosynthesis.

    Xiang-guang Lv

    Full Text Available A rice chlorophyll-deficient mutant w67 was isolated from an ethyl methane sulfonate (EMS-induced IR64 (Oryza sativa L. ssp. indica mutant bank. The mutant exhibited a distinct yellow-green leaf phenotype in the whole plant growth duration with significantly reduced levels of chlorophyll and carotenoid, impaired chloroplast development and lowered capacity of photosynthesis compared with the wild-type IR64. Expression of a number of genes associated with chlorophyll metabolism, chloroplast biogenesis and photosynthesis was significantly altered in the mutant. Genetic analysis indicated that the yellow-green phenotype was controlled by a single recessive nuclear gene located on the short arm of chromosome 3. Using map-based strategy, the mutation was isolated and predicted to encode a chloroplast signal recognition particle 43 KD protein (cpSRP43 with 388 amino acid residuals. A single base substitution from A to T at position 160 resulted in a premature stop codon. OscpSRP43 was constitutively expressed in various organs with the highest level in the leaf. Functional complementation could rescue the mutant phenotype and subcellular localization showed that the cpSRP43:GFP fusion protein was targeted to the chloroplast. The data suggested that Oryza sativa cpSRP43 (OscpSRP43 was required for the normal development of chloroplasts and photosynthesis in rice.

  16. Conformational changes in spinach (Spinacia oleracea leaves chloroplasts in vivo

    Janina Godziemba-Czyż

    2015-01-01

    Full Text Available Changes in the surface area of chloroplasts from intact cells of spinach leaves (\tSpinacia oleracea induced by blue (370—500 nm and red (600- 850 nm light of various intensity (102 - 5x105 erg cm-1s-1 were investigated. The changes are deseribed in terms of mean surface area in , μm2 and frequency of oocurrence of surface size classes. Low intensity blue light caused enlargement of the chloroplast surface (as compared with that in darkness, whereas high intensity light markedly reduced it. Exposure of chloroplasts to red light produces an increase of the surface in proportion to the intensity of the light and irradiation time.

  17. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts

    Nielsen, Agnieszka Janina Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos

    2016-01-01

    The chloroplasts found in plants and algae, and photosynthetic microorganisms such as cyanobacteria, are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused...... on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals, as well as complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression...... of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the production levels to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons...

  18. Chloroplast Iron Transport Proteins - Function and Impact on Plant Physiology.

    López-Millán, Ana F; Duy, Daniela; Philippar, Katrin

    2016-01-01

    Chloroplasts originated about three billion years ago by endosymbiosis of an ancestor of today's cyanobacteria with a mitochondria-containing host cell. During evolution chloroplasts of higher plants established as the site for photosynthesis and thus became the basis for all life dependent on oxygen and carbohydrate supply. To fulfill this task, plastid organelles are loaded with the transition metals iron, copper, and manganese, which due to their redox properties are essential for photosynthetic electron transport. In consequence, chloroplasts for example represent the iron-richest system in plant cells. However, improvement of oxygenic photosynthesis in turn required adaptation of metal transport and homeostasis since metal-catalyzed generation of reactive oxygen species (ROS) causes oxidative damage. This is most acute in chloroplasts, where radicals and transition metals are side by side and ROS-production is a usual feature of photosynthetic electron transport. Thus, on the one hand when bound by proteins, chloroplast-intrinsic metals are a prerequisite for photoautotrophic life, but on the other hand become toxic when present in their highly reactive, radical generating, free ionic forms. In consequence, transport, storage and cofactor-assembly of metal ions in plastids have to be tightly controlled and are crucial throughout plant growth and development. In the recent years, proteins for iron transport have been isolated from chloroplast envelope membranes. Here, we discuss their putative functions and impact on cellular metal homeostasis as well as photosynthetic performance and plant metabolism. We further consider the potential of proteomic analyses to identify new players in the field.

  19. Comparison of crude oil interfacial behavior

    Beetge, J.H.; Panchev, N. [Champion Technologies Inc., Fresno, TX (United States)

    2008-07-01

    The bulk properties of crude oil are used to predict its behaviour with regards to treatment, transport and processing. Surface active components, such as asphaltenes, are often used to study or explain critical interfacial behaviour of crude oil. This study investigated the differences and similarities in the interfacial behaviour of the collective surface active component in various crude oils from different sources. The properties of interfaces between crude oil and water were compared using a Teclis drop shape tensiometer. A portion of a crude oil sample was diluted in toluene and contacted with water in a rising drop configuration. Dynamic surface tension and interfacial rheology was examined as a function of time from the early stages of interface formation. Sinusoidal oscillation of the drop volume allowed for the evaluation of visco-elastic behaviour of the crude oil/water interface as it developed with time. The Gibbs elastic modulus, as well as its elastic and viscose components were calculated from the drop shape. The interfacial behaviour was expressed in terms of concentration, oscillation frequency and interface age. It was concluded that knowledge of crude oil interfacial character could be of value in the treatment, transport and processing of crude oils because the its behaviour may play a significant role in crude oil production and processing.

  20. Robust expression of a bioactive mammalian protein in chlamydomonas chloroplast

    Mayfield, Stephen P.

    2010-03-16

    Methods and compositions are disclosed to engineer chloroplast comprising heterologous mammalian genes via a direct replacement of chloroplast Photosystem II (PSII) reaction center protein coding regions to achieve expression of recombinant protein above 5% of total protein. When algae is used, algal expressed protein is produced predominantly as a soluble protein where the functional activity of the peptide is intact. As the host algae is edible, production of biologics in this organism for oral delivery or proteins/peptides, especially gut active proteins, without purification is disclosed.

  1. The action spectrum in chloroplast translocation in multilayer leaf cells

    Zbigniew Lechowski

    2015-01-01

    Full Text Available By measurement of light transmittance through a leaf as criterion of chloroplast translocation, the action spectrum of Ajuga reptans was established. In the spectrum obtained, a correction was introduced for leaf autoabsorption calculated on the basis of the Beer-Lambert law. The action spectrum has two maxima: at λ= 375 nm and λ= 481 nm. The range above 502 nm has no significant effect on chloroplast translocation. Comparison with other objects examined demonstrated that in multilayer leaf cells riboflavin seems also to be a photoreceptor active in this process.

  2. Incorporation of uridine-H3 into healthy and tobacco necrosis virus-infected mesophyll cells of Chenopodium amaranticolor

    Faccioli, G.; Rubies-Autonel, C.

    1975-01-01

    Tritiated uridine was selectively incorporated into the nucleus, nucleolus and cytoplasm of actinomycin D-treated Chenopodium amaranticolor cells locally infected with a strain of tobacco necrosis virus (TNV), 3 days after inoculation. Healthy cells did not show such an incorporation. Chloroplasts, in both types of cells, were free of label. Treatment with pancreatic ribonuclease removed the label completely in the majority of nuclei and nucleoli of infected cells. Since infectivity tests showed that AMD treatment increased virus multiplication by 10-12%, it is conceivable to think that the incorporation observed was due to virus synthesis. Preliminary infectivity experiments also showed that treatment of the cells with cycloheximide inhibited virus multiplication up to 80%, while chloramphenicol increased such multiplication. Our results lead to the conclusion that nucleus, nucleolus and cytoplasm but not chloroplasts are the sites involved in the synthesis of TNV. (orig.) [de

  3. Application of HB17, an Arabidopsis class II homeodomain-leucine zipper transcription factor, to regulate chloroplast number and photosynthetic capacity.

    Hymus, Graham J; Cai, Suqin; Kohl, Elizabeth A; Holtan, Hans E; Marion, Colleen M; Tiwari, Shiv; Maszle, Don R; Lundgren, Marjorie R; Hong, Melissa C; Channa, Namitha; Loida, Paul; Thompson, Rebecca; Taylor, J Philip; Rice, Elena; Repetti, Peter P; Ratcliffe, Oliver J; Reuber, T Lynne; Creelman, Robert A

    2013-11-01

    Transcription factors are proposed as suitable targets for the control of traits such as yield or food quality in plants. This study reports the results of a functional genomics research effort that identified ATHB17, a transcription factor from the homeodomain-leucine zipper class II family, as a novel target for the enhancement of photosynthetic capacity. It was shown that ATHB17 is expressed natively in the root quiescent centre (QC) from Arabidopsis embryos and seedlings. Analysis of the functional composition of genes differentially expressed in the QC from a knockout mutant (athb17-1) compared with its wild-type sibling revealed the over-representation of genes involved in auxin stimulus, embryo development, axis polarity specification, and plastid-related processes. While no other phenotypes were observed in athb17-1 plants, overexpression of ATHB17 produced a number of phenotypes in Arabidopsis including enhanced chlorophyll content. Image analysis of isolated mesophyll cells of 35S::ATHB17 lines revealed an increase in the number of chloroplasts per unit cell size, which is probably due to an increase in the number of proplastids per meristematic cell. Leaf physiological measurements provided evidence of improved photosynthetic capacity in 35S::ATHB17 lines on a per unit leaf area basis. Estimates of the capacity for ribulose-1,5-bisphosphate-saturated and -limited photosynthesis were significantly higher in 35S::ATHB17 lines.

  4. Kinetics of Ca2+- and ATP-dependent, voltage-controlled anion conductance in the plasma membrane of mesophyll cells of Pisum sativum

    Elzenga, J.T.M.; van Volkenburgh, E.

    Whole-cell patch-clamp techniques were used to measure anion currents through the plasma membrane of protoplasts of mesophyll cells of expanding pea (Pisum sativum L.) leaves. Voltage-induced changes of the currents could be modelled with single exponential activation and deactivation kinetics. The

  5. A new mechanism for the regulation of stomatal aperture size in intact leaves: accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba

    Lu, P.; Outlaw, W.H. Jr.; Smith, B.G.; Freed, G.A.

    1997-01-01

    At various times after pulse-labeling broad bean (Vicia faba L.) leaflets with 14CO2, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents, whereas those from rinsed peels contained only symplastic contents. Sucrose (Suc)-specific radioactivity peaked (111 GBq mol-1) in palisade cells at 20 min. In contrast, the 14C content and Suc-specific radioactivity were very low in guard cells for 20 min, implying little CO2 incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum Suc-specific radioactivity (204 GBq mol-1) and a high Suc influx rate (0.05 pmol stoma-1 min-1). These and other comparisons implied the presence of (a) multiple Suc pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived Suc in guard-cell walls sufficient to diminish stomatal opening by approximately 3 micrometers. Factors expected to enhance Suc accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic Suc concentration, which is elevated when mesophyll Suc efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal aperture size by this previously unrecognized mechanism

  6. 7 CFR 29.1010 - Crude.

    2010-01-01

    ... of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1010 Crude. A subdegree of maturity. Crude leaves are usually hard and slick as a result of extreme immaturity. A similar condition may result from fire-kill, sunburn, or sunscald. Any leaf...

  7. 7 CFR 29.3512 - Crude.

    2010-01-01

    ... of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3512 Crude. A subdegree of maturity. Crude leaves are usually hard and slick as a result of extreme immaturity. A similar condition may result from firekill, sunburn, or sunscald. Any leaf...

  8. 7 CFR 29.2261 - Crude.

    2010-01-01

    ... of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing.... A subdegree of maturity. Crude leaves are usually hard and slick as a result of extreme immaturity. A similar condition may result from fire-kill, sunburn, or sunscald. Any leaf which is crude to the...

  9. 7 CFR 30.20 - Crude.

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Crude. 30.20 Section 30.20 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... unfinished as a result of extreme immaturity. Crude tobacco ordinarily has a characteristic green color. ...

  10. Cyst(e)ine Is the Transport Metabolite of Assimilated Sulfur from Bundle-Sheath to Mesophyll Cells in Maize Leaves1

    Burgener, Marta; Suter, Marianne; Jones, Stephanie; Brunold, Christian

    1998-01-01

    The intercellular distribution of the enzymes and metabolites of assimilatory sulfate reduction and glutathione synthesis was analyzed in maize (Zea mays L. cv LG 9) leaves. Mesophyll cells and strands of bundle-sheath cells from second leaves of 11-d-old maize seedlings were obtained by two different mechanical-isolation methods. Cross-contamination of cell preparations was determined using ribulose bisphosphate carboxylase (EC 4.1.1.39) and nitrate reductase (EC 1.6.6.1) as marker enzymes for bundle-sheath and mesophyll cells, respectively. ATP sulfurylase (EC 2.7.7.4) and adenosine 5′-phosphosulfate sulfotransferase activities were detected almost exclusively in the bundle-sheath cells, whereas GSH synthetase (EC 6.3.2.3) and cyst(e)ine, γ-glutamylcysteine, and glutathione were located predominantly in the mesophyll cells. Feeding experiments using [35S]sulfate with intact leaves indicated that cyst(e)ine was the transport metabolite of reduced sulfur from bundle-sheath to mesophyll cells. This result was corroborated by tracer experiments, which showed that isolated bundle-sheath strands fed with [35S]sulfate secreted radioactive cyst(e)ine as the sole thiol into the resuspending medium. The results presented in this paper show that assimilatory sulfate reduction is restricted to the bundle-sheath cells, whereas the formation of glutathione takes place predominantly in the mesophyll cells, with cyst(e)ine functioning as a transport metabolite between the two cell types. PMID:9536048

  11. SKL1 Is Essential for Chloroplast Development in Arabidopsis

    Huimin Xu

    2018-02-01

    Full Text Available The Arabidopsis shikimate kinase-like 1 (skl1-8 mutant is characterized by a pigment-defective phenotype. Although the related phenotypical defect mainly has been attributed to the blocking of chloroplast development, the molecular functions of SKL1 remain largely unknown. In this study, we combined multiple approaches to investigate the potential functions of SKL1. Results showed that the skl1-8 mutant exhibited an albino phenotype and had dramatically reduced chlorophyll content as a consequence of a single nuclear recessive gene mutation. Chemical complementation analysis indicated that SKL1 does not function as SK enzyme in the shikimate pathway. In addition, by chlorophyll fluorescence parameters and immunoblot analysis, the levels of photosynthetic proteins are substantially reduced. Moreover, by transcriptome analysis, specific groups of nuclear genes involved in photosynthesis, such as light-harvesting complex, pigment metabolism, carbon metabolism, and chloroplast gene expression, were down-regulated, whereas several defense and oxidative stress responsive genes were up-regulated in the skl1-8 mutant compared with the wide type. Furthermore, we found the expression of genes related to auxin transport and response was repressed in the skl1-8 mutant, probable suggesting that SKL1 is involved in auxin-related pathways during chloroplast development. Together, these results provide a useful reference for characterization of SKL1 function during chloroplast biogenesis and development.

  12. Various types of chromoproteins extracted from tobacco chloroplasts

    Sirchis, Jean; Duranton, Jacques

    1959-01-01

    From tobacco chloroplasts a chroma-proteic complex is isolated; this can be fractionally divided into two different species by the difference in their chemical compositions and their speeds of sedimentation. Reprint of a paper published in 'Comptes Rendus des Seances de l'Academie des Sciences', tome 248, p. 2528-2530, sitting of 27 April 1959 [fr

  13. The TOC complex: preprotein gateway to the chloroplast.

    Andrès, Charles; Agne, Birgit; Kessler, Felix

    2010-06-01

    Photosynthetic eukaryotes strongly depend on chloroplast metabolic pathways. Most if not all involve nuclear encoded proteins. These are synthesized as cytosolic preproteins with N-terminal, cleavable targeting sequences (transit peptide). Preproteins are imported by a major pathway composed of two proteins complexes: TOC and TIC (Translocon of the Outer and Inner membranes of the Chloroplasts, respectively). These selectively recognize the preproteins and facilitate their transport across the chloroplast envelope. The TOC core complex consists of three types of components, each belonging to a small family: Toc34, Toc75 and Toc159. Toc34 and Toc159 isoforms represent a subfamily of the GTPase superfamily. The members of the Toc34 and Toc159 subfamily act as GTP-dependent receptors at the chloroplast surface and distinct members of each occur in defined, substrate-specific TOC complexes. Toc75, a member of the Omp85 family, is conserved from prokaryotes and functions as the unique protein-conducting channel at the outer membrane. In this review we will describe the current state of knowledge regarding the composition and function of the TOC complex.

  14. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts.

    Nielsen, Agnieszka Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos; Wlodarczyk, Artur Jacek; Gnanasekaran, Thiyagarajan; Perestrello Ramos H de Jesus, Maria; King, Brian Christopher; Bakowski, Kamil; Jensen, Poul Erik

    2016-07-01

    Chloroplasts in plants and algae and photosynthetic microorganisms such as cyanobacteria are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals and complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression of the appropriate pathways, but this requires optimization of carbon flux and reducing power, and a thorough understanding of regulatory pathways. Secretion or storage of the compounds produced can be exploited for the isolation or confinement of the desired compounds. In this review, we explore the use of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the levels of production to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons derived from the photosynthetic light reactions, appears to be non-limiting, but redirection of the fixed carbon via precursor molecules presents a challenge. We also discuss the available synthetic biology tools and the need to expand the molecular toolbox to facilitate cellular reprogramming for increased production yields in both cyanobacteria and chloroplasts. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  15. Abscisic acid represses the transcription of chloroplast genes

    Yamburenko, M.V.; Zubo, Y.O.; Vaňková, Radomíra; Kusnetsov, V.; Kulaeva, O.N.; Borner, T.

    2013-01-01

    Roč. 64, č. 14 (2013), s. 4491-4502 ISSN 0022-0957 R&D Projects: GA ČR GA522/09/2058 Institutional research plan: CEZ:AV0Z50380511 Keywords : Abscisic acid (ABA) * chloroplast * cytokinin Subject RIV: ED - Physiology Impact factor: 5.794, year: 2013

  16. Characterization of polymorphic SSRs among Prunus chloroplast genomes

    An in silico mining process yielded 80, 75, and 78 microsatellites in the chloroplast genome of Prunus persica, P. kansuensis, and P. mume. A and T repeats were predominant in the three genomes, accounting for 67.8% on average and most of them were successful in primer design. For the 80 P. persica ...

  17. Contribution of chloroplast DNA in the biodiversity of some Aegilops ...

    Four Aegilops species (Aegilops longissima, Aegilops speltoides, Aegilops searsii and Aegilops caudata) belonging to the family Poaceae were used in this study. Nucleotides of 1651 bp from 5.8 S rRNA gene and the intergenic spacers trnT-trnL and trnL-trnF from the chloroplast DNA were combined together in order to ...

  18. Functional characterization of recombinant chloroplast signal recognition particle

    Groves, M R; Mant, A; Kuhn, A; Koch, J; Dübel, S; Robinson, C; Sinning, I

    2001-01-01

    The signal recognition particle (SRP) is a ubiquitous system for the targeting of membrane and secreted proteins. The chloroplast SRP (cpSRP) is unique among SRPs in that it possesses no RNA and is functional in post-translational as well as co-translational targeting. We have expressed and purified

  19. Protein disorder in plants: a view from the chloroplast

    Yruela Inmaculada

    2012-09-01

    Full Text Available Abstract Background The intrinsically unstructured state of some proteins, observed in all living organisms, is essential for basic cellular functions. In this field the available information from plants is limited but it has been reached a point where these proteins can be comprehensively classified on the basis of disorder, function and evolution. Results Our analysis of plant genomes confirms that nuclear-encoded proteins follow the same trend than other multi-cellular eukaryotes; however, chloroplast- and mitochondria- encoded proteins conserve the patterns of Archaea and Bacteria, in agreement with their phylogenetic origin. Based on current knowledge about gene transference from the chloroplast to the nucleus, we report a strong correlation between the rate of disorder of transferred and nuclear-encoded proteins, even for polypeptides that play functional roles back in the chloroplast. We further investigate this trend by reviewing the set of chloroplast ribosomal proteins, one of the most representative transferred gene clusters, finding that the ribosomal large subunit, assembled from a majority of nuclear-encoded proteins, is clearly more unstructured than the small one, which integrates mostly plastid-encoded proteins. Conclusions Our observations suggest that the evolutionary dynamics of the plant nucleus adds disordered segments to genes alike, regardless of their origin, with the notable exception of proteins currently encoded in both genomes, probably due to functional constraints.

  20. Engineering the Chloroplast Genome of Oleaginous Marine Microalga Nannochloropsis oceanica

    Qinhua Gan

    2018-04-01

    Full Text Available Plastid engineering offers an important tool to fill the gap between the technical and the enormous potential of microalgal photosynthetic cell factory. However, to date, few reports on plastid engineering in industrial microalgae have been documented. This is largely due to the small cell sizes and complex cell-wall structures which make these species intractable to current plastid transformation methods (i.e., biolistic transformation and polyethylene glycol-mediated transformation. Here, employing the industrial oleaginous microalga Nannochloropsis oceanica as a model, an electroporation-mediated chloroplast transformation approach was established. Fluorescent microscopy and laser confocal scanning microscopy confirmed the expression of the green fluorescence protein, driven by the endogenous plastid promoter and terminator. Zeocin-resistance selection led to an acquisition of homoplasmic strains of which a stable and site-specific recombination within the chloroplast genome was revealed by sequencing and DNA gel blotting. This demonstration of electroporation-mediated chloroplast transformation opens many doors for plastid genome editing in industrial microalgae, particularly species of which the chloroplasts are recalcitrant to chemical and microparticle bombardment transformation.

  1. Expression of recombinant interferon α-2a in tobacco chloroplasts ...

    Chloroplast transformation was accomplished upon bombardment of fully expanded 4 to 6 weeks-old tobacco leaves using helium gun. Green shoots regenerated from single antibiotic resistant cells were subjected to further rounds of selection and regeneration to develop homoplasmic clones. The molecular analysis of ...

  2. Crude oil growth impact on pipelines

    Devries, O.

    2005-01-01

    This paper provided an outline of crude oil production and supply in Canada. Details of oil sands projects in Athabasca, Cold Lake and Peace River were presented. A chart of oil sands growth by major project was provided. A list of new emerging oil sands crude types was also presented along with details of a synthetic bitumen blending synergy. Maps of Western Canadian crude oil markets were provided, along with details of refinery and market demand by crude type. Various pipeline alternatives to new markets were examined, with reference to Enbridge Pipeline's supply and capacity. Details of the Hardisty to U.S Gulf Coast Pipeline and the Edmonton to Prince Rupert Pipeline and its terminal and dock facilities were presented. It was concluded that pipeline capacity and seasonal factors will influence market demand, while linefill, crude types and the quality of the product will influence operational strategies. tabs., figs

  3. Classification of weathered crude oils

    Vogt, N.B.; Sjoegren, C.E.; Lichtenthaler, G.

    1987-01-01

    The NORDTEST procedure (1) for oil spill identification has been applied successfully at several occasions. The NORDTEST procedure includes analyses of sulfur (XRF), vanadium and nickel (ICP/AAS), GC, HPLC and UV-fluorescence. The NORDTEST procedure does not include GC-MS as an analytical method. As part of a joint Nordic to evaluate the NORDTEST procedure for oil identification, with participants from Denmark, Sweden, Finland and Norway, thirty artificially weathered crude oils from four geographical regions have been analyzed (2). The analytical methods evaluated include sulfur analysis, vanadium and nickel analysis, infrared analysis, UV-fluorescence, gas chromatography, high pressure liquid chromatography and high resolution GC-mass spectrometry. Figure 1 shows the distribution of variables analyzed in each analytical method. The 190 variables from GC-MS were split into 7 groups according to chemical considerations. These were steranes (25 var.), triterpanes (16 var.), di(+)aromatics (63 var.), sulf. aromatics (30 var.), monoaromatics (19 var.), cycloalkanes (15 var.) and n-alkanes (22) variables. The data from these chemical analyses have been evaluated for use in oil spill identification purposes

  4. Redirecting the Cyanobacterial Bicarbonate Transporters BicA and SbtA to the Chloroplast Envelope: Soluble and Membrane Cargos Need Different Chloroplast Targeting Signals in Plants.

    Vivien eRolland

    2016-02-01

    Full Text Available Most major crops used for human consumption are C3 plants, which yields are limited by photosynthetic inefficiency. To circumvent this, it has been proposed to implement the cyanobacterial CO2-concentrating mechanism (CCM, principally consisting of bicarbonate transporters and carboxysomes, into plant chloroplasts. As it is currently not possible to recover homoplasmic transplastomic monocots, foreign genes must be introduced in these plants via nuclear transformation. Consequently, it is paramount to ensure that resulting proteins reach the appropriate sub-cellular compartment, which for cyanobacterial transporters BicA and SbtA, is the chloroplast inner-envelope membrane (IEM. At present, targeting signals to redirect large transmembrane proteins from non-chloroplastic organisms to plant chloroplast envelopes are unknown. The goal of this study was to identify such signals, using agrobacteria-mediated transient expression and confocal microscopy to determine the sub-cellular localization of ~37 GFP-tagged chimeras. Initially, fragments of chloroplast proteins known to target soluble cargos to the stroma were tested for their ability to redirect BicA, but they proved ineffective. Next, different N-terminal regions from Arabidopsis IEM transporters were tested. We demonstrated that the N-terminus of AtHP59, AtPLGG1 or AtNTT1 (92-115 amino acids, containing a cleavable chloroplast transit peptide (cTP and a membrane protein leader (MPL, was sufficient to redirect BicA or SbtA to the chloroplast envelope. This constitutes the first evidence that nuclear-encoded transmembrane proteins from non-chloroplastic organisms can be targeted to the envelope of plant chloroplasts; a finding which represents an important advance in chloroplast engineering by opening up the door to further manipulation of the chloroplastic envelope.

  5. Biodegradability of northern crude oil

    Cook, F D; Westlake, D W.S.

    1976-01-01

    Field studies on the microbiological degradation of crude oils encompassed the placing of oil-soaked plots in two areas in the Northwest Territories and Alberta. Replicate plots received amendments of fertilizer, oil-utilizing bacteria, fertilizer plus bacteria or were untreated except for the oil. Changes in microbial numbers and chemical composition of recovered oil were determined periodically. The initial stimulatory effect on bacterial numbers brought about by the addition of fertilizers to oil-soaked plots diminished two years after the application to a point where the differences were no longer significant. Experiments carried out in the Norman Wells area to determine the effect of the amount of fertilizer applied on oil degradation have yielded inconclusive results. The data suggest that at least 2.7 kg of urea-phosphate fertilizer per kl of oil is required to maintain a reasonable oil degradation rate. Preliminary studies on the use of fertilizer coated with chemicals to increase its hydrophobic character indicate that they could be useful in treating wet-land oil spills. Soils from the McKenzie River drainage basin indicate that bacteria are present which can use oil under mesophilic conditions. However, the ability to use the same oil under psychrophilic conditions is more restricted. At least one bacterial species from each mixed population studied was capable of bringing about chemical changes in oil similar to those observed for the original mixed culture. The potential hazards and uses of the seeding of oil spills is discussed relative to the environmental conditions found in the northern part of Canada. 35 refs., 2 figs., 15 tabs.

  6. Manipulation of Glutathione and Amino Acid Biosynthesis in the Chloroplast1

    Noctor, Graham; Arisi, Ana-Carolina M.; Jouanin, Lise; Foyer, Christine H.

    1998-01-01

    Poplars (Populus tremula × Populus alba) were transformed to overexpress Escherichia coli γ-glutamylcysteine synthetase (γ-ECS) or glutathione synthetase in the chloroplast. Five independent lines of each transformant strongly expressed the introduced gene and possessed markedly enhanced activity of the gene product. Glutathione (GSH) contents were unaffected by high chloroplastic glutathione synthetase activity. Enhanced chloroplastic γ-ECS activity markedly increased γ-glutamylcysteine and GSH levels. These effects are similar to those previously observed in poplars overexpressing these enzymes in the cytosol. Similar to cytosolic γ-ECS overexpression, chloroplastic overexpression did not deplete foliar cysteine or methionine pools and did not lead to morphological changes. Light was required for maximal accumulation of GSH in poplars overexpressing γ-ECS in the chloroplast. High chloroplastic, but not cytosolic, γ-ECS activities were accompanied by increases in amino acids synthesized in the chloroplast. We conclude that (a) GSH synthesis can occur in the chloroplast and the cytosol and may be up-regulated in both compartments by increased γ-ECS activity, (b) interactions between GSH synthesis and the pathways supplying the necessary substrates are similar in both compartments, and (c) chloroplastic up-regulation of GSH synthesis is associated with an activating effect on the synthesis of specific amino acids formed in the chloroplast. PMID:9765532

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

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

    2016-09-01

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

  8. Analysis of chlorophyll fluorescence reveals stage specific patterns of chloroplast-containing cells during Arabidopsis embryogenesis

    RICARDO I TEJOS

    2010-01-01

    Full Text Available The basic body plan of a plant is established early in embryogenesis when cells differentiate, giving rise to the apical and basal regions of the embryo. Using chlorophyll fluorescence as a marker for chloroplasts, we have detected specific patterns of chloroplast-containing cells at specific stages of embryogenesis. Non-randomly distributed chloroplast-containing cells are seen as early as the globular stage of embryogenesis in Arabidopsis. In the heart stage of embryogenesis, chloroplast containing cells are detected in epidermal cells as well as a central region of the heart stage embryo, forming a triangular septum of chloroplast-containing cells that divides the embryo into three equal sectors. Torpedo stage embryos have chloroplast-containing epidermal cells and a central band of chloroplast-containing cells in the cortex layer, just below the shoot apical meristem. In the walking-stick stage of embryogenesis, chloroplasts are present in the epidermal, cortex and endodermal cells. The chloroplasts appear reduced or absent from the provascular and columella cells of walking-stick stage embryos. These results suggest that there is a tight regulation of plastid differentiation during embryogenesis that generates specific patterns of chloroplast-containing cells in specific cell layers at specific stages of embryogenesis.

  9. Chloroplast Dynamics and Photosynthetic Efficiency: Final Technical Report

    Hanson, Maureen [Cornell Univ., Ithaca, NY (United States)

    2016-11-03

    This project investigated the mechanism by which chloroplasts position themselves to maximize solar energy utilization, to enhance gas exchange, to minimize environmental stress, and to promote efficient exchange of metabolites with other compartments within the plant cell. Chloroplasts move within leaf cells to optimize light levels, moving toward levels of light useful for photosynthesis while moving away from excess light. Plastids sometimes extend their reach by sending out projections (stromules) that can connect anchor chloroplasts in position within the cell or provide close contacts with plasma membrane, mitochondria, peroxisomes, endoplasmic reticulum, and the nucleus. The intracellular location of chloroplasts in relation to other organelles with which they share biosynthetic pathways, such as peroxisomes and mitochondria in photorespiration, affects metabolite flow. This work contributed to the knowledge of the mechanisms of organelle movement and anchoring in specific locations in plant cells and how proteins traffic within the cell. We identified two domains on 12 of the 13 Arabidopsis myosins that were similar to the vacuole-binding (V) domain characterized in yeast and to the DIL domain characterized in yeast and mouse as required for secretory vesicle or melanosome movement, respectively. Because all of the Arabidopsis regions with homology to the V domain contain the amino acid sequence PAL, we refer to this region as the Arabidopsis PAL domain. We have used the yeast Myo2p tail structural information to model the 12 myosin XI tail domains containing the homologous PAL and DIL domains. Eight YFP::DIL domain fusions labeled peroxisomes; none labeled mitochondria or chloroplasts. Six myosin XI Vacuole domains labeled mitochondria and seven labeled Golgi bodies. The Arabidopsis myosin XI-F PAL domain and the homologous myosin XI-F PAL domain from N. benthamiana labels chloroplasts and stromules in N. benthamiana leaves. Using an Arabidopsis line

  10. Bacterial consortia for crude oil spill remediation

    Chhatre, S.; Purohit, H.; Shanker, R.; Khanna, P.

    1996-01-01

    Oil spills generate enormous public concern and highlight the need for cost effective ad environmentally acceptable mitigation technologies. Physico-chemical methods are not completely effective after a spill. Hence, there is a need for improved and alternative technologies. Bioremediation is the most environmentally sound technology for clean up. This report intends to determine the potential of a bacterial consortium for degradation of Gulf and Bombay High crude oil. A four membered consortium was designed that could degrade 70% of the crude oil. A member of consortium produced a biosurfactant, rhamnolipid, that emulsified crude oil efficiently for effective degradation by the other members of consortium. The wide range of hydrocarbonoclastic capabilities of the selected members of bacterial consortium leads to the degradation of both aromatic and aliphatic fractions of crude oil in 72 hours. (Author)

  11. Degradation of crude oil by marine cyanobacteria

    Raghukumar, C.; Vipparty, V.; David, J.J.; Chandramohan, D.

    The marine cyanobacteria Oscillatoria salina Biswas, Plectonema terebrans Bornet et Flanhault and Aphanocapsa sp. degraded Bombay High crude oil when grown in artificial seawater nutrients as well as in plain natural seawater. Oil removals...

  12. Valorization of crude glycerol from biodiesel production

    Konstantinović Sandra S.

    2016-01-01

    Full Text Available The increased production of biodiesel as an alternative fuel involves the simultaneous growth in production of crude glycerol as its main by-product. Therefore, the feasibility and sustainability of biodiesel production requires the effective utilization of crude glycerol. This review describes various uses of crude glycerol as a potential green solvent for chemical reactions, a starting raw material for chemical and biochemical conversions into value-added chemicals, a substrate or co-substrate in microbial fermentations for synthesis of valuable chemicals and production of biogas and biohydrogen as well as a feedstuff for animal feed. A special attention is paid to various uses of crude glycerol in biodiesel production. [Projekat Ministarstva nauke Republike Srbije, br. III 45001

  13. Export crudes for the '90s

    Rhodes, A.K.

    1992-01-01

    This paper supplies statistical data on the characteristics of Tapais blend (Malaysia), Cold Lake blend (Alta), and Arabian Light (Saudi Arabia) crude oils. Temperature range, API gravity, sulfur percentage, viscosity, nitrogen content, and other data are provided

  14. REVIEW OF PVT CORRELATIONS FOR CRUDE OILS

    win

    approaches that of the fluids used. During the last 50 years, ... applied to crude oils from other regions (Sutton and Farshad,. 1990). ... S. S. Ikiensikimama, Department of Chemistry Engineering, University of Lagos, Lagos, Nigeria. O. Ogboja ...

  15. The dynamics of crude oil price differentials

    Fattouh, Bassam

    2010-01-01

    Crude oil price differentials are modelled as a two-regime threshold autoregressive (TAR) process using the method proposed by Caner and Hansen [Caner, M., Hansen, B.E. Threshold autoregression with a unit root. Econometrica 2001; 69; 1555-1596.]. While standard unit root tests suggest that the prices of crude oil of different varieties move closely together such that their price differential is stationary, the TAR results indicate strong evidence of threshold effects in the adjustment process to the long-run equilibrium. These findings suggest that crude oil prices are linked and thus at the very general level, the oil market is 'one great pool' (Adelman, M.A. International oil agreements. The Energy Journal 1984; 5; 1-9.). However, differences in the dynamics of adjustment suggest that within this one pool, oil markets are not necessarily integrated in every time period and hence the dynamics of crude oil price differentials may not follow a stationary process at all times. Although the development of a liquid futures market around the crude oil benchmarks has helped make some distant markets more unified, arbitrage is not costless or risk-free and temporary breakdowns in the benchmarks can lead to decoupling of crude oil prices. (author)

  16. Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis

    Rodermel, Steven

    2015-11-16

    The immutans (im) variegation mutant of Arabidopsis is an ideal model to gain insight into factors that control chloroplast biogenesis. im defines the gene for PTOX, a plastoquinol terminal oxidase that participates in control of thylakoid redox. Here, we report that the im defect can be suppressed during the late stages of plant development by gigantea (gi2), which defines the gene for GIGANTEA (GI), a central component of the circadian clock that plays a poorly-understood role in diverse plant developmental processes. imgi2 mutants are late-flowering and display other well-known phenotypes associated with gi2, such as starch accumulation and resistance to oxidative stress. We show that the restoration of chloroplast biogenesis in imgi2 is caused by a developmental-specific de-repression of cytokinin signaling that involves crosstalk with signaling pathways mediated by gibberellin (GA) and SPINDLY (SPY), a GA response inhibitor. Suppression of the plastid defect in imgi2 is likely caused by a relaxation of excitation pressures in developing plastids by factors contributed by gi2, including enhanced rates of photosynthesis and increased resistance to oxidative stress. Interestingly, the suppression phenotype of imgi can be mimicked by crossing im with the starch accumulation mutant, sex1, perhaps because sex1 utilizes pathways similar to gi. We conclude that our studies provide a direct genetic linkage between GIGANTEA and chloroplast biogenesis, and we construct a model of interactions between signaling pathways mediated by gi, GA, SPY, cytokinins, and sex1 that are required for chloroplast biogenesis.

  17. Chloroplast Genome Evolution in Early Diverged Leptosporangiate Ferns

    Kim, Hyoung Tae; Chung, Myong Gi; Kim, Ki-Joong

    2014-01-01

    In this study, the chloroplast (cp) genome sequences from three early diverged leptosporangiate ferns were completed and analyzed in order to understand the evolution of the genome of the fern lineages. The complete cp genome sequence of Osmunda cinnamomea (Osmundales) was 142,812 base pairs (bp). The cp genome structure was similar to that of eusporangiate ferns. The gene/intron losses that frequently occurred in the cp genome of leptosporangiate ferns were not found in the cp genome of O. c...

  18. Biparental chloroplast inheritance leads to rescue from cytonuclear incompatibility.

    Barnard-Kubow, Karen B; McCoy, Morgan A; Galloway, Laura F

    2017-02-01

    Although organelle inheritance is predominantly maternal across animals and plants, biparental chloroplast inheritance has arisen multiple times in the angiosperms. Biparental inheritance has the potential to impact the evolutionary dynamics of cytonuclear incompatibility, interactions between nuclear and organelle genomes that are proposed to be among the earliest types of genetic incompatibility to arise in speciation. We examine the interplay between biparental inheritance and cytonuclear incompatibility in Campanulastrum americanum, a plant species exhibiting both traits. We first determine patterns of chloroplast inheritance in genetically similar and divergent crosses, and then associate inheritance with hybrid survival across multiple generations. There is substantial biparental inheritance in C. americanum. The frequency of biparental inheritance is greater in divergent crosses and in the presence of cytonuclear incompatibility. Biparental inheritance helps to mitigate cytonuclear incompatibility, leading to increased fitness of F 1 hybrids and recovery in the F 2 generation. This study demonstrates the potential for biparental chloroplast inheritance to rescue cytonuclear compatibility, reducing cytonuclear incompatibility's contribution to reproductive isolation and potentially slowing speciation. The efficacy of rescue depended upon the strength of incompatibility, with a greater persistence of weak incompatibilities in later generations. These findings suggest that incompatible plastids may lead to selection for biparental inheritance. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  19. Novel efficient methods for measuring mesophyll anatomical characteristics from fresh thick sections using stereology and confocal microscopy: application on acid rain-treated Norway spruce needles

    Albrechtová, Jana; Janáček, Jiří; Lhotáková, Zuzana; Radochová, Barbora; Kubínová, Lucie

    2007-01-01

    Roč. 58, č. 6 (2007), s. 1451-1461 ISSN 0022-0957 R&D Projects: GA AV ČR IAA5011810; GA AV ČR(CZ) IAA600110507; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z60050516 Keywords : mesophyll * stereology * confocal microscopy Subject RIV: EA - Cell Biology Impact factor: 3.917, year: 2007

  20. Effects of herbicides on /sup 14/CO/sub 2/ fixation in isolated mesophyll cells from Beta vulgaris (sugar beet) and Chenopodium album

    Baumann, G; Guenther, G [Paedagogische Hochschule Karl Liebknecht, Potsdam (German Democratic Republic)

    1979-01-01

    10/sup -4/ - 10/sup -6/ molar solutions of herbicides (atrazine, 2,4-D, desmetryne, diallate, diquat, feuron, lenacil, NaTa, paraquat, phenmedipham, prometryne, propham, pyrazone, and simazine) cause similar inhibitory effects on the photosynthetic /sup 14/CO/sub 2/ fixation in isolated mesophyll cells from Chenopodium album and Beta vulgaris. Correlatdion between inhibition and herbicide resistance of the whole plants could be realized for lenacil only.

  1. Exploring photosynthesis evolution by comparative analysis of metabolic networks between chloroplasts and photosynthetic bacteria

    Hou Jing

    2006-04-01

    Full Text Available Abstract Background Chloroplasts descended from cyanobacteria and have a drastically reduced genome following an endosymbiotic event. Many genes of the ancestral cyanobacterial genome have been transferred to the plant nuclear genome by horizontal gene transfer. However, a selective set of metabolism pathways is maintained in chloroplasts using both chloroplast genome encoded and nuclear genome encoded enzymes. As an organelle specialized for carrying out photosynthesis, does the chloroplast metabolic network have properties adapted for higher efficiency of photosynthesis? We compared metabolic network properties of chloroplasts and prokaryotic photosynthetic organisms, mostly cyanobacteria, based on metabolic maps derived from genome data to identify features of chloroplast network properties that are different from cyanobacteria and to analyze possible functional significance of those features. Results The properties of the entire metabolic network and the sub-network that consists of reactions directly connected to the Calvin Cycle have been analyzed using hypergraph representation. Results showed that the whole metabolic networks in chloroplast and cyanobacteria both possess small-world network properties. Although the number of compounds and reactions in chloroplasts is less than that in cyanobacteria, the chloroplast's metabolic network has longer average path length, a larger diameter, and is Calvin Cycle -centered, indicating an overall less-dense network structure with specific and local high density areas in chloroplasts. Moreover, chloroplast metabolic network exhibits a better modular organization than cyanobacterial ones. Enzymes involved in the same metabolic processes tend to cluster into the same module in chloroplasts. Conclusion In summary, the differences in metabolic network properties may reflect the evolutionary changes during endosymbiosis that led to the improvement of the photosynthesis efficiency in higher plants. Our

  2. Early H2O2 Accumulation in Mesophyll Cells Leads to Induction of Glutathione during the Hyper-Sensitive Response in the Barley-Powdery Mildew Interaction1

    Vanacker, Helene; Carver, Tim L.W.; Foyer, Christine H.

    2000-01-01

    H2O2 production and changes in glutathione, catalase, and peroxidase were followed in whole-leaf extracts from the susceptible (AlgS [Algerian/4* (F14) Man.(S)]; ml-a1 allele) and resistant (AlgR [Algerian/4* (F14) Man.(R)]; Ml-a1 allele) barley (Hordeum vulgare) isolines between 12 and 24 h after inoculation with powdery mildew (Blumeria graminis [DC]. Speer [syn. Erysiphe graminis DC] f.sp hordei Marchal). Localized papilla responses and cell death hypersensitive responses were not observed within the same cell. In hypersensitive response sites, H2O2 accumulation first occurred in the mesophyll underlying the attacked epidermal cell. Subsequently, H2O2 disappeared from the mesophyll and accumulated around attacked epidermal cells. In AlgR, transient glutathione oxidation coincided with H2O2 accumulation in the mesophyll. Subsequently, total foliar glutathione and catalase activities transiently increased in AlgR. These changes, absent from AlgS, preceded inoculation-dependent increases in peroxidase activity that were observed in both AlgR and AlgS at 18 h. An early intercellular signal precedes H2O2, and this elicits anti-oxidant responses in leaves prior to events leading to death of attacked cells. PMID:10938348

  3. Large-scale protein-protein interaction analysis in Arabidopsis mesophyll protoplasts by split firefly luciferase complementation.

    Li, Jian-Feng; Bush, Jenifer; Xiong, Yan; Li, Lei; McCormack, Matthew

    2011-01-01

    Protein-protein interactions (PPIs) constitute the regulatory network that coordinates diverse cellular functions. There are growing needs in plant research for creating protein interaction maps behind complex cellular processes and at a systems biology level. However, only a few approaches have been successfully used for large-scale surveys of PPIs in plants, each having advantages and disadvantages. Here we present split firefly luciferase complementation (SFLC) as a highly sensitive and noninvasive technique for in planta PPI investigation. In this assay, the separate halves of a firefly luciferase can come into close proximity and transiently restore its catalytic activity only when their fusion partners, namely the two proteins of interest, interact with each other. This assay was conferred with quantitativeness and high throughput potential when the Arabidopsis mesophyll protoplast system and a microplate luminometer were employed for protein expression and luciferase measurement, respectively. Using the SFLC assay, we could monitor the dynamics of rapamycin-induced and ascomycin-disrupted interaction between Arabidopsis FRB and human FKBP proteins in a near real-time manner. As a proof of concept for large-scale PPI survey, we further applied the SFLC assay to testing 132 binary PPIs among 8 auxin response factors (ARFs) and 12 Aux/IAA proteins from Arabidopsis. Our results demonstrated that the SFLC assay is ideal for in vivo quantitative PPI analysis in plant cells and is particularly powerful for large-scale binary PPI screens.

  4. Large-scale protein-protein interaction analysis in Arabidopsis mesophyll protoplasts by split firefly luciferase complementation.

    Jian-Feng Li

    Full Text Available Protein-protein interactions (PPIs constitute the regulatory network that coordinates diverse cellular functions. There are growing needs in plant research for creating protein interaction maps behind complex cellular processes and at a systems biology level. However, only a few approaches have been successfully used for large-scale surveys of PPIs in plants, each having advantages and disadvantages. Here we present split firefly luciferase complementation (SFLC as a highly sensitive and noninvasive technique for in planta PPI investigation. In this assay, the separate halves of a firefly luciferase can come into close proximity and transiently restore its catalytic activity only when their fusion partners, namely the two proteins of interest, interact with each other. This assay was conferred with quantitativeness and high throughput potential when the Arabidopsis mesophyll protoplast system and a microplate luminometer were employed for protein expression and luciferase measurement, respectively. Using the SFLC assay, we could monitor the dynamics of rapamycin-induced and ascomycin-disrupted interaction between Arabidopsis FRB and human FKBP proteins in a near real-time manner. As a proof of concept for large-scale PPI survey, we further applied the SFLC assay to testing 132 binary PPIs among 8 auxin response factors (ARFs and 12 Aux/IAA proteins from Arabidopsis. Our results demonstrated that the SFLC assay is ideal for in vivo quantitative PPI analysis in plant cells and is particularly powerful for large-scale binary PPI screens.

  5. Amino acid transport across the tonoplast of vacuoles isolated from barley mesophyll protoplasts: Uptake of alanine, leucine, and glutamine

    Dietz, K.J.; Jaeger, R.; Kaiser, G.; Martinoia, E.

    1990-01-01

    Mesophyll protoplasts from leaves of well-fertilized barley (Hordeum vulgare L.) plants contained amino acids at concentrations as high as 120 millimoles per liter. With the exception of glutamic acid, which is predominantly localized in the cytoplasm, a major part of all other amino acids was contained inside the large central vacuole. Alanine, leucine, and glutamine are the dominant vacuolar amino acids in barley. Their transport into isolated vacuoles was studied using 14 C-labeled amino acids. Uptake was slow in the absence of ATP. A three- to sixfold stimulation of uptake was observed after addition of ATP or adenylyl imidodiphosphate an ATP analogue not being hydrolyzed by ATPases. Other nucleotides were ineffective in increasing the rate of uptake. ATP-Stimulated amino acid transport was not dependent on the transtonoplast pH or membrane potential. p-Chloromercuriphenylsulfonic acid and n-ethyl maleimide increased transport independently of ATP. Neutral amino acids such as valine or leucine effectively decreased the rate of alanine transport. Glutamine and glycine were less effective or not effective as competitive inhibitors of alanine transport. The results indicate the existence of a uniport translocator specific for neutral or basic amino acids that is under control of metabolic effectors

  6. Influence of Drought on Mesophyll Resistance to CO2 Diffusion and its Impact on Water-Use Efficiency in Trees

    Guo, J.; Beverly, D.; Cook, C.; Ewers, B. E.; Williams, D. G.

    2015-12-01

    The resistance to CO2 diffusion inside leaves (mesophyll resistance; rm) during photosynthesis is often comparable in magnitude to stomatal diffusion resistance, and varies among species and across environmental conditions. Consequently, photosynthesis is strongly limited by rm at low internal CO2 partial pressures, such that its variation may determine patterns of leaf water-use efficiency (WUE). Reduction in stomatal conductance with drought typically increases WUE, but also decreases photosynthesis. In theory, the decrease in photosynthesis could be countered by reduction in rm while maintaining high WUE. It is still uncertain how drought-related changes in rm affect short- and long-term WUE strategies of different tree species. We conducted field observations of instantaneous WUE and 13C discrimination in two dominant conifer species (Pinus contorta and Picea engelmannii) in SE Wyoming over the seasonal dry-down period in the summer of 2015. rm was examined by on-line 13C discrimination using isotope laser spectroscopy. Controlled environment studies on three conifer species (P. contorta, P. engelmannii, and Abies lasiocarpa) and one angiosperm (Populus tremuloides) are in progress. We hypothesize that the plasticity of rm in response to drought accounts for significant adjustments in photosynthetic capacity and WUE. Needle leaf conifers are known to have relatively high rm, and we expect them to show greater improvements in photosynthesis and WUE when rm is decreased compared to angiosperm tree species.

  7. Phosphorus compounds, proteins, nuclease and acid phosphatase activities in isolated spinach chloroplasts

    E. Mikulska

    2015-01-01

    Full Text Available This paper deals with attempts to elaborate a simple method of spinach chloroplast isolation ensuring a high proportion of intact chloroplasts. We obtained 3 preparations of isolated chloroplasts. Several preliminary analyses of the obtained chloroplast fraction were also performed. Phosphorus compounds, total protein and the enzyme activities of RNase, DNase and GPase were determined. We found: 0,36-0,59% of RNA, 0,19-0,24% of DNA, 2,1-2,9% of phospholipids and 26-28% of protein. RNase activity was very high.

  8. Sonication-based isolation and enrichment of Chlorella protothecoides chloroplasts for illumina genome sequencing

    Angelova, Angelina [University of Arizona; Park, Sang-Hycuk [University of Arizona; Kyndt, John [Bellevue University; Fitzsimmons, Kevin [University of Arizona; Brown, Judith K [University of Arizona

    2013-09-01

    With the increasing world demand for biofuel, a number of oleaginous algal species are being considered as renewable sources of oil. Chlorella protothecoides Krüger synthesizes triacylglycerols (TAGs) as storage compounds that can be converted into renewable fuel utilizing an anabolic pathway that is poorly understood. The paucity of algal chloroplast genome sequences has been an important constraint to chloroplast transformation and for studying gene expression in TAGs pathways. In this study, the intact chloroplasts were released from algal cells using sonication followed by sucrose gradient centrifugation, resulting in a 2.36-fold enrichment of chloroplasts from C. protothecoides, based on qPCR analysis. The C. protothecoides chloroplast genome (cpDNA) was determined using the Illumina HiSeq 2000 sequencing platform and found to be 84,576 Kb in size (8.57 Kb) in size, with a GC content of 30.8 %. This is the first report of an optimized protocol that uses a sonication step, followed by sucrose gradient centrifugation, to release and enrich intact chloroplasts from a microalga (C. prototheocoides) of sufficient quality to permit chloroplast genome sequencing with high coverage, while minimizing nuclear genome contamination. The approach is expected to guide chloroplast isolation from other oleaginous algal species for a variety of uses that benefit from enrichment of chloroplasts, ranging from biochemical analysis to genomics studies.

  9. Does a voltage-sensitive outer envelope transport mechanism contributes to the chloroplast iron uptake?

    Solti, Ádám; Kovács, Krisztina; Müller, Brigitta; Vázquez, Saúl; Hamar, Éva; Pham, Hong Diep; Tóth, Brigitta; Abadía, Javier; Fodor, Ferenc

    2016-12-01

    Based on the effects of inorganic salts on chloroplast Fe uptake, the presence of a voltage-dependent step is proposed to play a role in Fe uptake through the outer envelope. Although iron (Fe) plays a crucial role in chloroplast physiology, only few pieces of information are available on the mechanisms of chloroplast Fe acquisition. Here, the effect of inorganic salts on the Fe uptake of intact chloroplasts was tested, assessing Fe and transition metal uptake using bathophenantroline-based spectrophotometric detection and plasma emission-coupled mass spectrometry, respectively. The microenvironment of Fe was studied by Mössbauer spectroscopy. Transition metal cations (Cd 2+ , Zn 2+ , and Mn 2+ ) enhanced, whereas oxoanions (NO 3 - , SO 4 2- , and BO 3 3- ) reduced the chloroplast Fe uptake. The effect was insensitive to diuron (DCMU), an inhibitor of chloroplast inner envelope-associated Fe uptake. The inorganic salts affected neither Fe forms in the uptake assay buffer nor those incorporated into the chloroplasts. The significantly lower Zn and Mn uptake compared to that of Fe indicates that different mechanisms/transporters are involved in their acquisition. The enhancing effect of transition metals on chloroplast Fe uptake is likely related to outer envelope-associated processes, since divalent metal cations are known to inhibit Fe 2+ transport across the inner envelope. Thus, a voltage-dependent step is proposed to play a role in Fe uptake through the chloroplast outer envelope on the basis of the contrasting effects of transition metal cations and oxoaninons.

  10. Pengaruh Penambahan Kosubstrat pada Biodegradasi Crude Oil

    Any Juliani

    2016-06-01

    Full Text Available Kegiatan penambangan minyak bumi tidak hanya dilakukan oleh perusahaan-perusahaan besar, tetapi juga oleh masyarakat secara tradisional. Potensi pencemaran lingkungan yang ditimbulkan oleh kegiatan penambangan rakyat ini menjadi lebih tinggi karena pengelolaannya yang tradisional. Salah satu jenis pencemaran yang ditimbulkannya misalnya adalah tanah atau perairan yang tercemar oleh minyak bumi (crude oil pada saat berlangsungnya kegiatan penambangan. Salah satu upaya untuk dapat mengatasinya adalah dengan bioremediasi. Bioremediasi merupakan teknologi pengolahan pencemar dengan memanfaatkan aktivitas mikroba, terutama dari golongan bakteri. Bioremediasi tersebut harus melibatkan bakteri yang memiliki kapasitas metabolic untuk melakukan biodegradasi terhadap crude oil tersebut. Crude oil sendiri pada dasarnya merupakan senyawa hidrokarbon yang merupakan sumber karbon yang kaya bagi mikroba. Namun demikian, biodegradasi crude oil relative lebih sulit dilakukan karena karakteristiknya yang merupakan senyawa dengan berat molekul dan ukuran yang besar. Oleh karena itu penambahan kosubstrat yang lebih sederhana dapat dilakukan untuk membantu biodegradasi terutama pada tahap awal proses. Penelitian ini dilakukan untuk mengetahui pengaruh penambahan kosubstrat dalam hal ini glukosa terhadap biodegradasi crude oil. Penelitian dilakukan dalam media cair dengan bioaugmentasi melalui penambahan inoculum bakteri yang diisolasi dari tanah yang dikondisikan terhadap crude oil dalam beberapa variasi reactor. Indikasi terjadinya biodegradasi diperiksa melalui pengukuran terhadap parameter Total Petroleum Hydrocarbon (TPH dan Total Plate Count (TPC. Hasil penelitian menunjukkan bahwa penambahan kosubstrat glukosa memberikan pengaruh positif terhadap penurunan TPH. Penurunan TPH tertinggi setelah 28 hari adalah sebesar 25,3 % yang diberikan oleh reactor dengan penambahan kosubstrat serta konsentrasi crude oil awal sebesar 8.1 %. Sementara itu reactor tanpa

  11. Rate of biodegradation of crude oil by microorganisms isolated from ...

    The rate of biodegradation of crude oil by micro-organisms isolated from crude oil sludge environment in Eket, Akwa Ibom State of Nigeria was studied. Mineral salt medium supplemented with crude oil was used and three most abundant species isolated from a crude oil sludged soil - Micrococcus varians, Bacillus subtilis ...

  12. Crude oil spot market pricing: Pearsonian analysis of crude oil spot market prices

    Akinnusi, Ayo

    1994-01-01

    This paper presents a brief overview of crude oil pricing before describing a study of sets of 1991 spot market prices, and examining Pearson's model. Empirical distribution characteristics for 14 crude oils are tabulated, and skewness-kurtosis relationship and implication are considered. (UK)

  13. When Will Occur the Crude Oil Bubbles?

    Su, Chi-Wei; Li, Zheng-Zheng; Chang, Hsu-Ling; Lobonţ, Oana-Ramona

    2017-01-01

    In this paper, we apply a recursive unit root test to investigate whether there exist multiple bubbles in crude oil price. The method is best suited for a practical implementation of a time series and delivers a consistent date-stamping strategy for the origination and termination of multiple bubbles. The empirical result indicates that there exist six bubbles during 1986–2016 when the oil price deviate from its intrinsic value based on market fundamentals. Specifically, oil price contains the fundamentals and bubble components. The dates of the bubbles correspond to specific events in the politics and financial markets. The authorities should actively fight speculative bubbles or just observe their evolutions and speculation activities may decrease, which is favour of the stabilisation of the staple commodities including crude oil price. These findings have important economic and policy implications to recognise the cause of bubbles and take corresponding measures to reduce the impact on the real economy cause of the fluctuation of crude oil price. - Highlights: • Investigate multiple bubbles in crude oil price. • Indicate six bubbles deviate from its intrinsic value based on market fundamentals. • The bubbles correspond to specific events in the politics and financial markets. • Reduce the impact on the real economy cause of the fluctuation of crude oil price.

  14. Oxidative damage to chloroplasts from Chlorella vulgaris exposed to ultraviolet-B radiation

    Malanga, G.; Calmanovici, G.; Puntarulo, S.

    1997-01-01

    Upon UV-B irradiation, Chlorella vulgaris cells and isolated chloroplasts increased in size and starch accumulation. Photosynthetic capacity and chlorophyll content of chloroplasts isolated from irradiated algae decreased by 72 and 66%, as compared to chloroplasts isolated from control cells. Dihydrorhodamine 123 conversion to rhodamine 123 was used as a sensitive method for detection of peroxide (presumably hydrogen peroxide) formation in isolated chloroplasts. The accumulation of rhodamine 123 is higher in irradiated than in nonirradiated chloroplasts and the increased accumulation of rhodamine 123 depended on the UV-B dose. Quantitation of alkyl radical-EPR signals in chloroplasts indicated that UV-B exposure significantly increased radical content in the membranes. The content of an oxidized DNA base (8-hydroxy-2′-deoxyguanosine) in chloroplasts was increased by 72 and 175% after irradiation of the algal culture with 17.3 and 42.6 kJ m −2 , respectively. The chloroplastic activity of superoxide dismutase decreased by 50% as compared with control values after irradiation with 42.6 kJ m −2 and no changes in ascorbate peroxidase activity and ascorbic acid content were detected at the irradiation doses tested. The β-carotene content in chloroplasts was not affected by the irradiation, but the α-tocopherol content increased approximately 4-fold after UV-B irradiation. The results suggest that oxidative damage related to UV-B exposure is responsible for alterations in chloroplasts function and integrity, and that an antioxidant response is triggered in chloroplasts through an increase in α-tocopherol content. (author)

  15. Comparative toxicology of four crude oils

    Clarke, L.M.; Hodson, P.V. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology; Brown, R.S. [Queen' s Univ., Kingston, ON (Canada). Dept. of Chemistry

    2003-07-01

    Fish that are chronically exposed to polycyclic aromatic hydrocarbons (PAHs) exhibit dioxin-like toxicity characterized by blue sac disease and the induction of cytochrome P4501A (CYP1A). This study compared the relative toxicity of four crude oils (Scotian Shelf, MESA, the synthetic Alberta Sweet Mixed Blend, and Alaskan North Slope Crude Oil), in causing the disease in rainbow trout embryos living in simulated spawning beds with hydrocarbon-contaminated gravel. Each oil had different chemical characteristics and PAH concentrations. The study confirmed the assumption that the Alberta Sweet Mixed Blend would be the most toxic due to its high PAH concentration. The results suggest that the main cause of toxicity in crude oil is due to the presence, concentration, and conformation of specific PAHs.

  16. Forecasting volatility of crude oil markets

    Kang, Sang Hoon; Kang, Sang-Mok; Yoon, Seong-Min

    2009-01-01

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  17. Forecasting volatility of crude oil markets

    Kang, Sang Hoon [Department of Business Administration, Gyeongsang National University, Jinju, 660-701 (Korea); Kang, Sang-Mok; Yoon, Seong-Min [Department of Economics, Pusan National University, Busan, 609-735 (Korea)

    2009-01-15

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  18. GENETIC POLYMORPHISM IN GYMNODINIUM GALATHEANUM CHLOROPLAST DNA SEQUENCES AND DEVELOPMENT OF A MOLECULAR DETECTION ASSAY. (R827084)

    Nuclear and chloroplast-encoded small subunit ribosomal DNA sequences were obtainedfrom several strains of the toxic dinoflagellate Gymnodinium galatheanum. Phylogenetic analyses andcomparison of sequences indicate that the chloroplast sequences show a higher degree of se...

  19. Crude oil hedging: benchmarking price protection strategies

    Krapels, Edward N.; Pratt, Michael

    1998-01-01

    This report presents a review of hedging (protection against a loss) strategies in the crude oil futures and options markets. The introductory section of the report gives details of hedging instruments, and the purposes of hedging crude oil. Hedging strategies including pure futures strategies, pure options strategies, options combination strategies, exotic (Asian) options strategies, and insurance instruments are described. The West Texas intermediate (WTI) market depth, liquidity and hedging effectiveness are examined, and winners and losers, and energy consumers are considered. The appendix gives tables and charts summarising the outcomes of futures and options strategies under different market conditions and expectations. (UK)

  20. De Novo Assembly of Complete Chloroplast Genomes from Non-model Species Based on a K-mer Frequency-Based Selection of Chloroplast Reads from total DNA Sequences.

    Izan, Shairul; Esselink, G.; Visser, R.G.F.; Smulders, M.J.M.; Borm, T.J.A.

    2017-01-01

    Whole Genome Shotgun (WGS) sequences of plant species often contain an abundance of reads that are derived from the chloroplast genome. Up to now these reads have generally been identified and assembled into chloroplast genomes based on homology to chloroplasts from related species. This

  1. Early local differentiation of the cell wall matrix defines the contact sites in lobed mesophyll cells of Zea mays.

    Giannoutsou, E; Sotiriou, P; Apostolakos, P; Galatis, B

    2013-10-01

    The morphogenesis of lobed mesophyll cells (MCs) is highly controlled and coupled with intercellular space formation. Cortical microtubule rings define the number and the position of MC isthmi. This work investigated early events of MC morphogenesis, especially the mechanism defining the position of contacts between MCs. The distributions of plasmodesmata, the hemicelluloses callose and (1 → 3,1 → 4)-β-d-glucans (MLGs) and the pectin epitopes recognized by the 2F4, JIM5, JIM7 and LM6 antibodies were studied in the cell walls of Zea mays MCs. Matrix cell wall polysaccharides were immunolocalized in hand-made sections and in sections of material embedded in LR White resin. Callose was also localized using aniline blue in hand-made sections. Plasmodesmata distribution was examined by transmission electron microscopy. Before reorganization of the dispersed cortical microtubules into microtubule rings, particular bands of the longitudinal MC walls, where the MC contacts will form, locally differentiate by selective (1) deposition of callose and the pectin epitopes recognized by the 2F4, LM6, JIM5 and JIM7 antibodies, (2) degradation of MLGs and (3) formation of secondary plasmodesmata clusterings. This cell wall matrix differentiation persists in cell contacts of mature MCs. Simultaneously, the wall bands between those of future cell contacts differentiate with (1) deposition of local cell wall thickenings including cellulose microfibrils, (2) preferential presence of MLGs, (3) absence of callose and (4) transient presence of the pectins identified by the JIM5 and JIM7 antibodies. The wall areas between cell contacts expand determinately to form the cell isthmi and the cell lobes. The morphogenesis of lobed MCs is characterized by the early patterned differentiation of two distinct cell wall subdomains, defining the sites of the future MC contacts and of the future MC isthmi respectively. This patterned cell wall differentiation precedes cortical microtubule

  2. Greater efficiency of water use in poplar clones having a delayed response of mesophyll conductance to drought.

    Théroux Rancourt, Guillaume; Éthier, Gilbert; Pepin, Steeve

    2015-02-01

    Improvement of water use efficiency is a key objective to improve the sustainability of cultivated plants, especially fast growing species with high water consumption like poplar. It is well known that water use efficiency (WUE) varies considerably among poplar genotypes, and it was recently suggested that the use of the mesophyll-to-stomatal conductance ratio (gm/gs) would be an appropriate trait to improve WUE. The responses of 7-week-old cuttings of four hybrid poplar clones and one native Balsam poplar (Populus balsamifera L.) to a water stress-recovery cycle were examined to evaluate the relation between the gm/gs ratio and transpiration efficiency (TE), a leaf-level component of WUE. A contrasting gs response to water stress was observed among the five clones, from stomatal closure early on during soil drying up to limited closure in Balsam poplar. However in the hybrids, the decline in gm was consistently delayed by a few days compared with gs. Moreover, in the most water use-efficient hybrids, the recovery following rehydration occurred faster for gm than for gs. Thus, the delay in the response of gm to drought and its faster recovery upon rewatering increased the gm/gs of the hybrids and this ratio scaled positively with TE. Our results support the use of the gm/gs ratio to select genotypes with improved WUE, and the notion that breeding strategies focusing mainly on stomatal responses to soil drying should also look for a strong curvilinearity between net carbon assimilation rate and gs, the indication of a significant increase in gm/gs in the earlier stages of stomatal closure. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Ion and metabolite transport in the chloroplast of algae: lessons from land plants.

    Marchand, Justine; Heydarizadeh, Parisa; Schoefs, Benoît; Spetea, Cornelia

    2018-06-01

    Chloroplasts are endosymbiotic organelles and play crucial roles in energy supply and metabolism of eukaryotic photosynthetic organisms (algae and land plants). They harbor channels and transporters in the envelope and thylakoid membranes, mediating the exchange of ions and metabolites with the cytosol and the chloroplast stroma and between the different chloroplast subcompartments. In secondarily evolved algae, three or four envelope membranes surround the chloroplast, making more complex the exchange of ions and metabolites. Despite the importance of transport proteins for the optimal functioning of the chloroplast in algae, and that many land plant homologues have been predicted, experimental evidence and molecular characterization are missing in most cases. Here, we provide an overview of the current knowledge about ion and metabolite transport in the chloroplast from algae. The main aspects reviewed are localization and activity of the transport proteins from algae and/or of homologues from other organisms including land plants. Most chloroplast transporters were identified in the green alga Chlamydomonas reinhardtii, reside in the envelope and participate in carbon acquisition and metabolism. Only a few identified algal transporters are located in the thylakoid membrane and play role in ion transport. The presence of genes for putative transporters in green algae, red algae, diatoms, glaucophytes and cryptophytes is discussed, and roles in the chloroplast are suggested. A deep knowledge in this field is required because algae represent a potential source of biomass and valuable metabolites for industry, medicine and agriculture.

  4. Study of the interaction of cytochrome c and ferredoxine with the double membrane of chloroplast

    Neuburger, M.; Joyard, J.; Douce, R.

    1975-01-01

    The adsorption of two 59 Fe-labelled proteins on the chloroplast envelope was studied. The former molecule used was ferredoxine extracted from spinach leaves, the latter was cytochrome c, extracted from yeast (Saccharomyces cerevisiae D 261). The chloroplast envelope is thought to be involved in the transport of some proteins such as ferredoxine synthetized in the cytoplasm [fr

  5. Chloroplast microsatellites reveal population genetic diversity in red pine, Pinus resinosa Ait

    Craig S. Echt; L.L. DeVerno; M. Anzidei; G.G. Vendramin

    1998-01-01

    Variation in paternally inherited chloroplast microsatellite (cpSSR) DNA was used to study population genetic structure in red pine (Pinus resinosa Ait.), a species characterized by morphological uniformity, no allozyme variation, and limited RAPD variation. Using nine cpSSR loci, a total of 23 chloroplast haplotypes and 25 cpSSR alleles were were...

  6. The diurnal logic of the expression of the chloroplast genome in Chlamydomonas reinhardtii.

    Adam D Idoine

    Full Text Available Chloroplasts are derived from cyanobacteria and have retained a bacterial-type genome and gene expression machinery. The chloroplast genome encodes many of the core components of the photosynthetic apparatus in the thylakoid membranes. To avoid photooxidative damage and production of harmful reactive oxygen species (ROS by incompletely assembled thylakoid protein complexes, chloroplast gene expression must be tightly regulated and co-ordinated with gene expression in the nucleus. Little is known about the control of chloroplast gene expression at the genome-wide level in response to internal rhythms and external cues. To obtain a comprehensive picture of organelle transcript levels in the unicellular model alga Chlamydomonas reinhardtii in diurnal conditions, a qRT-PCR platform was developed and used to quantify 68 chloroplast, 21 mitochondrial as well as 71 nuclear transcripts in cells grown in highly controlled 12 h light/12 h dark cycles. Interestingly, in anticipation of dusk, chloroplast transcripts from genes involved in transcription reached peak levels first, followed by transcripts from genes involved in translation, and finally photosynthesis gene transcripts. This pattern matches perfectly the theoretical demands of a cell "waking up" from the night. A similar trend was observed in the nuclear transcripts. These results suggest a striking internal logic in the expression of the chloroplast genome and a previously unappreciated complexity in the regulation of chloroplast genes.

  7. Genetic analysis of a Microseris douglasii (Asteraceae) population polymorphic for an alien chloroplast type

    Roelofs, Dick; Bachmann, Konrad

    1997-01-01

    Recent evidence suggests chloroplast introgression from Microseris bigelovii into M. douglasii. We have examined 23 plants from a population of M. douglasii polymorphic for M. douglasii and M. bigelovii chloroplast types. All 23 plants were completely homozygous for morphological and RAPD markers,

  8. Effect of alkyl-N-phenylcarbamates on photochemical activity of spinach chloroplasts

    Sersen, F.; Kralova, K.; Macho, V.

    1999-01-01

    This study is aimed to investigate the effect of alkyl-N-phenylcarbamates on photosynthetic electron transport in spinach chloroplasts, to determine site of action in the photosynthetic apparatus of spinach chloroplasts and to find correlations between their structure and biological activity. (authors)

  9. Characterization of mango (Mangifera indica L.) transcriptome and chloroplast genome.

    Azim, M Kamran; Khan, Ishtaiq A; Zhang, Yong

    2014-05-01

    We characterized mango leaf transcriptome and chloroplast genome using next generation DNA sequencing. The RNA-seq output of mango transcriptome generated >12 million reads (total nucleotides sequenced >1 Gb). De novo transcriptome assembly generated 30,509 unigenes with lengths in the range of 300 to ≥3,000 nt and 67× depth of coverage. Blast searching against nonredundant nucleotide databases and several Viridiplantae genomic datasets annotated 24,593 mango unigenes (80% of total) and identified Citrus sinensis as closest neighbor of mango with 9,141 (37%) matched sequences. The annotation with gene ontology and Clusters of Orthologous Group terms categorized unigene sequences into 57 and 25 classes, respectively. More than 13,500 unigenes were assigned to 293 KEGG pathways. Besides major plant biology related pathways, KEGG based gene annotation pointed out active presence of an array of biochemical pathways involved in (a) biosynthesis of bioactive flavonoids, flavones and flavonols, (b) biosynthesis of terpenoids and lignins and (c) plant hormone signal transduction. The mango transcriptome sequences revealed 235 proteases belonging to five catalytic classes of proteolytic enzymes. The draft genome of mango chloroplast (cp) was obtained by a combination of Sanger and next generation sequencing. The draft mango cp genome size is 151,173 bp with a pair of inverted repeats of 27,093 bp separated by small and large single copy regions, respectively. Out of 139 genes in mango cp genome, 91 found to be protein coding. Sequence analysis revealed cp genome of C. sinensis as closest neighbor of mango. We found 51 short repeats in mango cp genome supposed to be associated with extensive rearrangements. This is the first report of transcriptome and chloroplast genome analysis of any Anacardiaceae family member.

  10. Analysis of Acorus calamus chloroplast genome and its phylogenetic implications.

    Goremykin, Vadim V; Holland, Barbara; Hirsch-Ernst, Karen I; Hellwig, Frank H

    2005-09-01

    Determining the phylogenetic relationships among the major lines of angiosperms is a long-standing problem, yet the uncertainty as to the phylogenetic affinity of these lines persists. While a number of studies have suggested that the ANITA (Amborella-Nymphaeales-Illiciales-Trimeniales-Aristolochiales) grade is basal within angiosperms, studies of complete chloroplast genome sequences also suggested an alternative tree, wherein the line leading to the grasses branches first among the angiosperms. To improve taxon sampling in the existing chloroplast genome data, we sequenced the chloroplast genome of the monocot Acorus calamus. We generated a concatenated alignment (89,436 positions for 15 taxa), encompassing almost all sequences usable for phylogeny reconstruction within spermatophytes. The data still contain support for both the ANITA-basal and grasses-basal hypotheses. Using simulations we can show that were the ANITA-basal hypothesis true, parsimony (and distance-based methods with many models) would be expected to fail to recover it. The self-evident explanation for this failure appears to be a long-branch attraction (LBA) between the clade of grasses and the out-group. However, this LBA cannot explain the discrepancies observed between tree topology recovered using the maximum likelihood (ML) method and the topologies recovered using the parsimony and distance-based methods when grasses are deleted. Furthermore, the fact that neither maximum parsimony nor distance methods consistently recover the ML tree, when according to the simulations they would be expected to, when the out-group (Pinus) is deleted, suggests that either the generating tree is not correct or the best symmetric model is misspecified (or both). We demonstrate that the tree recovered under ML is extremely sensitive to model specification and that the best symmetric model is misspecified. Hence, we remain agnostic regarding phylogenetic relationships among basal angiosperm lineages.

  11. Reducing the cadmium content of crude phosphates and mineral fertilizers

    Plessen, H von; Schimmel, G

    1987-10-01

    Crude sedimentary phosphates generally contain cadmium together with traces of other heavy metals. These Cd traces generally end up in fertilizers produced from the crude phosphates. Processes have therefore been developed to separate the Cd from the crude phosphate or from the crude phosphoric acids arising therefrom as intermediates. In this way, the Cd content of the crude phosphate can be reduced to less the 10% of its original value, and to 50% thereof by extractive treatment with acidic calcium nitrate solution. Older calcination processes for crude phosphate have been improved to give residual Cd contents of 10 to 50% at temperatures of 800 to 1000/sup 0/C. Cadmium can be removed almost quantitatively from crude phosphate by means of dialkyl dithiophosphoric acid esters by extraction, binding to adsorbents, or ion flotation. Cadmium can be extracted from crude acids in high yield by long-chained amines. After partial neutralization of the crude acids, precipitation as cadmium sulphide is also possible.

  12. Biotin Carboxyl Carrier Protein in Barley Chloroplast Membranes

    Kannangara, C. G.; Jense, C J

    1975-01-01

    Biotin localized in barley chloroplast lamellae is covalently bound to a single protein with an approximate molecular weight of 21000. It contains one mole of biotin per mole of protein and functions as a carboxyl carrier in the acetyl-CoA carboxylase reaction. The protein was obtained by solubil...... by solubilization of the lamellae in phenol/acetic acid/8 M urea. Feeding barley seedlings with [14C]-biotin revealed that the vitamin is not degraded into respiratory substrates by the plant, but is specifically incorporated into biotin carboxyl carrier protein....

  13. Chloroplast Movement May Impact Plant Phenotyping and Photochemistry Results

    Malas, J.; Pleban, J. R.; Wang, D. R.; Riley, C.; Mackay, D. S.

    2017-12-01

    Investigating phenotypic responses of crop species across environmental conditions is vital to improving agricultural productivity. Crop production is closely linked with photosynthetic activity, which can be evaluated using parameters such as relative chlorophyll, SPAD, and variable chlorophyll fluorescence. Recently, a handheld device known as the MultispeQ emerged on the market as an open-source instrument that aims to provide high-output, high-quality field data at a low cost to the plant research community. MultispeQ takes measurements of both environmental conditions (light intensity, temperature, humidity, etc.) and photosynthetic parameters (relative chlorophyll, SPAD, photosystem II quantum efficiency (FII), and non-photochemical quenching (NPQ)). Data are automatically backed up and shared on the PhotosynQ network, which serves as a collaborative platform for researchers and professionals. Here, we used the instrument to quantify photosynthetic time-courses of two Brassica rapa genotypes in response to two contrasting nutrient management strategies (Control; High Nitrogen). Previous research found that chloroplast movement is one strategy plants use to optimize photosynthesis across varying light conditions. We were able to detect chloroplast movement throughout the day using the MultispeQ device. Our results support the idea that chloroplast movement serves both as an intrinsic feature of the circadian clock and as a light avoidance strategy. Under low light conditions (PAR 0-300) more light at the near-infrared and red regions was absorbed than under higher light conditions (PAR 500-800). In one genotype by treatment combination, absorbance at 730nm was around 60% at low light, versus only 30% at high light conditions. In light of our results that relative chlorophyll may change throughout a day, we suggest that it is important to take note of these effects when collecting photosynthesis efficiency data in order to avoid bias in measurements. We also

  14. The complete chloroplast genome sequence of Hibiscus syriacus.

    Kwon, Hae-Yun; Kim, Joon-Hyeok; Kim, Sea-Hyun; Park, Ji-Min; Lee, Hyoshin

    2016-09-01

    The complete chloroplast genome sequence of Hibiscus syriacus L. is presented in this study. The genome is composed of 161 019 bp in length, with a typical circular structure containing a pair of inverted repeats of 25 745 bp of length separated by a large single-copy region and a small single-copy region of 89 698 bp and 19 831 bp of length, respectively. The overall GC content is 36.8%. One hundred and fourteen genes were annotated, including 81 protein-coding genes, 4 ribosomal RNA genes and 29 transfer RNA genes.

  15. The complete chloroplast genome sequence of Curcuma flaviflora (Curcuma).

    Zhang, Yan; Deng, Jiabin; Li, Yangyi; Gao, Gang; Ding, Chunbang; Zhang, Li; Zhou, Yonghong; Yang, Ruiwu

    2016-09-01

    The complete chloroplast (cp) genome of Curcuma flaviflora, a medicinal plant in Southeast Asia, was sequenced. The genome size was 160 478 bp in length, with 36.3% GC content. A pair of inverted repeats (IRs) of 26 946 bp were separated by a large single copy (LSC) of 88 008 bp and a small single copy (SSC) of 18 578 bp, respectively. The cp genome contained 132 annotated genes, including 79 protein coding genes, 30 tRNA genes, and four rRNA genes. And 19 of these genes were duplicated in inverted repeat regions.

  16. The complete chloroplast genome sequence of Dendrobium officinale.

    Yang, Pei; Zhou, Hong; Qian, Jun; Xu, Haibin; Shao, Qingsong; Li, Yonghua; Yao, Hui

    2016-01-01

    The complete chloroplast sequence of Dendrobium officinale, an endangered and economically important traditional Chinese medicine, was reported and characterized. The genome size is 152,018 bp, with 37.5% GC content. A pair of inverted repeats (IRs) of 26,284 bp are separated by a large single-copy region (LSC, 84,944 bp) and a small single-copy region (SSC, 14,506 bp). The complete cp DNA contains 83 protein-coding genes, 39 tRNA genes and 8 rRNA genes. Fourteen genes contained one or two introns.

  17. Hartmut Lichtenthaler: an authority on chloroplast structure and isoprenoid biochemistry.

    Sharkey, Thomas D; Govindjee

    2016-05-01

    We pay tribute to Hartmut Lichtenthaler for making important contributions to the field of photosynthesis research. He was recently recognized for ground-breaking discoveries in chloroplast structure and isoprenoid biochemistry by the Rebeiz Foundation for Basic Research (RFBR; http://vlpbp.org/ ), receiving a 2014 Lifetime Achievement Award for Photosynthesis. The ceremony, held in Champaign, Illinois, was attended by many prominent researchers in the photosynthesis field. We provide below a brief note on his education, and then describe some of the areas in which Hartmut Lichtenthaler has been a pioneer.

  18. Carbon Dioxide Fixation in Isolated Kalanchoe Chloroplasts 1

    Levi, Carolyn; Gibbs, Martin

    1975-01-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 μmoles of CO2 per milligram of chlorophyll per hour. The dark rate of fixation was about 1% of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1,6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO2 fixation were primarily those of the photosynthetic carbon reduction cycle. PMID:16659249

  19. The evolution of blue-greens and the origins of chloroplasts

    Schwartz, R. M.; Dayhoff, M. O.

    1981-01-01

    All of the available molecular data support the theory that the chloroplasts of eukaryote cells were originally free-living blue-greens. Of great interest is what the relationships are between contemporary types of blue-greens and eukaryote chloroplasts and whether the chloroplasts of the various eukaryotes are the result of one or more than one symbiosis. By combining information from phylogenetic trees based on cytochrome c6 and 2Fe-2S ferredoxin sequences, it is shown that the chloroplasts of a number of eukaryote algae as well as the protist Euglena are polyphyletic; the chloroplasts of green algae and the higher plants may be the result of a single symbiosis.

  20. An Arabidopsis chloroplast-targeted Hsp101 homologue, APG6, has an essential role in chloroplast development as well as heat-stress response.

    Myouga, Fumiyoshi; Motohashi, Reiko; Kuromori, Takashi; Nagata, Noriko; Shinozaki, Kazuo

    2006-10-01

    Analysis of albino or pale-green (apg) mutants is important for identifying nuclear genes responsible for chloroplast development and pigment synthesis. We have identified 38 apg mutants by screening 11 000 Arabidopsis Ds-tagged lines. One mutant, apg6, contains a Ds insertion in a gene encoding APG6 (ClpB3), a homologue of the heat-shock protein Hsp101 (ClpB1). We isolated somatic revertants and identified two Ds-tagged and one T-DNA-tagged mutant alleles of apg6. All three alleles gave the same pale-green phenotype. These results suggest that APG6 is important for chloroplast development. The APG6 protein contains a transit peptide and is localized in chloroplasts. The plastids of apg6 pale-green cells were smaller than those of the wild type, and contained undeveloped thylakoid membranes. APG6 mRNA accumulated in response to heat shock in various organs, but not in response to other abiotic stresses. Under normal conditions, APG6 is constitutively expressed in the root tips, the organ boundary region, the reproductive tissues of mature plants where plastids exist as proplastids, and slightly in the stems and leaves. In addition, constitutive overexpression of APG6 in transgenic plants inhibited chloroplast development and resulted in a mild pale-green phenotype. The amounts of chloroplast proteins related to photosynthesis were markedly decreased in apg6 mutants. These results suggest that APG6 functions as a molecular chaperone involved in plastid differentiation mediating internal thylakoid membrane formation and conferring thermotolerance to chloroplasts during heat stress. The APG6 protein is not only involved in heat-stress response in chloroplasts, but is also essential for chloroplast development.

  1. Phytochemical and antimicrobial screening of crude extracts ...

    The bark and wood parts of the root of Terminalia mollis was investigated for its phytochemical and antimicrobial properties. Phytochemical screening showed the presence of tannins and resins as the major secondary metabolites. Test for antimicrobial activity of the plant crude extracts using the agar diffusion method ...

  2. Biogeochemistry of anaerobic crude oil biodegradation

    Head, Ian; Gray, Neil; Aitken, Caroline; Sherry, Angela; Jones, Martin; Larter, Stephen

    2010-05-01

    Anaerobic degradation of crude oil and petroleum hydrocarbons is widely recognized as a globally significant process both in the formation of the world's vast heavy oil deposits and for the dissipation of hydrocarbon pollution in anoxic contaminated environments. Comparative analysis of crude oil biodegradation under methanogenic and sulfate-reducing conditions has revealed differences not only in the patterns of compound class removal but also in the microbial communities responsible. Under methanogenic conditions syntrophic associations dominated by bacteria from the Syntropheaceae are prevalent and these are likely key players in the initial anaerobic degradation of crude oil alkanes to intermediates such as hydrogen and acetate. Syntrophic acetate oxidation plays an important role in these systems and often results in methanogenesis dominated by CO2 reduction by members of the Methanomicrobiales. By contrast the bacterial communities from sulfate-reducing crude oil-degrading systems were more diverse and no single taxon dominated the oil-degrading sulfate-reducing systems. All five proteobacterial subdivisions were represented with Delta- and Gammaproteobacteria being detected most consistently. In sediments which were pasteurized hydrocarbon degradation continued at a relatively low rate. Nevertheless, alkylsuccinates characteristic of anaerobic hydrocarbon degradation accumulated to high concentrations. This suggested that the sediments harbour heat resistant, possibly spore-forming alkane degrading sulfate-reducers. This is particularly interesting since it has been proposed recently, that spore-forming sulfate-reducing bacteria found in cold arctic sediments may have originated from seepage of geofluids from deep subsurface hydrocarbon reservoirs.

  3. Refining crude oils and gasolines, etc

    1931-11-23

    A process of refining crude oils and gasolines distilled from shale and the like is described, consisting of submitting them to a prewash with soda, an oxidation preferably with hypochlorite solution, a hydrogenation with nascent hydrogen, and finally rectification and neutralization.

  4. ASSESSMENT OF HEAVY METALS AND CRUDE PROTEIN ...

    UNICORN

    to quantify heavy metals (Cu, Zn, Pb and Cd) and crude protein content of these species that are sold in ... in protein, omega 3 and low fat content. Furthermore ... high levels of cadmium can cause kidney and liver damage in man [6]. Motivation .... analysis. Determination of heavy metals in the edible tissues of the organisms.

  5. 7 CFR 29.2511 - Crude.

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Crude. 29.2511 Section 29.2511 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... leaves are usually hard and slick as a result of extreme immaturity. A similar condition may result from...

  6. Heavy oils processing materials requirements crude processing

    Sloley, Andrew W. [CH2M Hill, Englewood, CO (United States)

    2012-07-01

    Over time, recommended best practices for crude unit materials selection have evolved to accommodate new operating requirements, feed qualities, and product qualities. The shift to heavier oil processing is one of the major changes in crude feed quality occurring over the last 20 years. The three major types of crude unit corrosion include sulfidation attack, naphthenic acid attack, and corrosion resulting from hydrolyzable chlorides. Heavy oils processing makes all three areas worse. Heavy oils have higher sulfur content; higher naphthenic acid content; and are more difficult to desalt, leading to higher chloride corrosion rates. Materials selection involves two major criteria, meeting required safety standards, and optimizing economics of the overall plant. Proper materials selection is only one component of a plant integrity approach. Materials selection cannot eliminate all corrosion. Proper materials selection requires appropriate support from other elements of an integrity protection program. The elements of integrity preservation include: materials selection (type and corrosion allowance); management limits on operating conditions allowed; feed quality control; chemical additives for corrosion reduction; and preventive maintenance and inspection (PMI). The following discussion must be taken in the context of the application of required supporting work in all the other areas. Within that context, specific materials recommendations are made to minimize corrosion due to the most common causes in the crude unit. (author)

  7. Waxy crude oil flow restart ability

    Sierra, Andre Gaona; Varges, Priscilla Ribeiro; Mendes, Paulo Roberto de Souza [Dept. of Mechanical Engineering. Pontificia Universidade Catolica do Rio de Janeiro, RJ (Brazil)], e-mails: prvarges@puc-rio.br, pmendes@puc-rio.br; Ziglio, Claudio [PETROBRAS S.A, R.J., Rio de Janeiro, RJ (Brazil)], e-mail: ziglio@petrobras.com.br

    2010-07-01

    Under the hot reservoir conditions, waxy crudes behave like Newtonian fluids but once they experience very cold temperatures on the sea floor, the heavy paraffin's begin to precipitate from the solution impacting non- Newtonian flow behavior to the crude (Chang 2000, Lee 2009, Davidson 2004) and begin to deposit on the pipe wall leave blocked of pipeline. This gel cannot be broken with the original steady state flow operating pressure applied before gelation (Chang 1998). Restarting waxy crude oil flows in pipelines is a difficult issue because of the complex rheological behavior of the gelled oil. Indeed, below the WAT, the gelled oil exhibits viscoplastic, thixotropic, temperature-dependent, and compressible properties due to the interlocking gel-like structure formed by the crystallized paraffin compounds and the thermal shrinkage of the oil. The main objective of this work is to determine the minimal pressure to restart the flow, and the relationship between the fluid rheology , pipe geometry and the restart pressure of the flow. Experiments will be performed to investigate the displacement of carbopol aqueous solutions (viscoplastic fluid without thixotropic effects) by Newtonian oil flowing through a strait pipe to validate the experimental apparatus. Therefore, tests will be made with different fluids, like Laponite and waxy crude oils. (author)

  8. Phytochemical analysis and antimicrobial screening of crude ...

    The leaves, stem bark and root bark of Ekebergia senegalensis, which has some traditional medicinal applications were investigated. Phytochemical analysis gave positive results for carbohydrates, glycosides, saponins, tannins and alkaloids. The crude methanol extracts showed growth inhibitory effects on Salmonella ...

  9. PDV2 has a dosage effect on chloroplast division in Arabidopsis.

    Chang, Ning; Sun, Qingqing; Li, Yiqiong; Mu, Yajuan; Hu, Jinglei; Feng, Yue; Liu, Xiaomin; Gao, Hongbo

    2017-03-01

    PDV2 has a dosage effect on chloroplast division in Arabidopsis thaliana , but this effect may vary in different plants. Chloroplasts have to be divided as plants grow to maintain an optimized number in the cell. Chloroplasts are divided by protein complexes across the double membranes from the stroma side to the cytosolic side. PDV2 is a chloroplast division protein on the chloroplast outer membrane. It recruits the dynamin-related GTPase ARC5 to the division site. The C-terminus of PDV2 and the C-terminus of ARC6 interact in the intermembrane space, which is important for the localization of PDV2. Previously, it was shown that overexpression of PDV2 can increase the division of chloroplasts in Arabidopsis and moss, so the authors concluded that PDV2 determines the rate of chloroplast division in land plants. PDV2 was also shown to inhibit the GTPase activity of ARC5 by in vitro experiment. These results look to be contradictory. Here, we identified a null allele of PDV2 in Arabidopsis and studied plants with different levels of PDV2. Our results suggested that the chloroplast division phenotype in Arabidopsis is sensitive to the level of PDV2, while this is not the case for ARC6. The level of PDV2 protein is reduced sharply in fast-growing leaves, while the level of ARC6 is not. The levels of PDV2 and ARC6 in several other plant species at different developmental stages were also investigated. The results indicated that their expression pattern varies in different species. Thus, PDV2 is an important positive factor of chloroplast division with an apparent dosage effect in Arabidopsis, but this effect for different chloroplast division proteins in different plants may vary.

  10. The complete chloroplast genome of banana (Musa acuminata, Zingiberales): insight into plastid monocotyledon evolution.

    Martin, Guillaume; Baurens, Franc-Christophe; Cardi, Céline; Aury, Jean-Marc; D'Hont, Angélique

    2013-01-01

    Banana (genus Musa) is a crop of major economic importance worldwide. It is a monocotyledonous member of the Zingiberales, a sister group of the widely studied Poales. Most cultivated bananas are natural Musa inter-(sub-)specific triploid hybrids. A Musa acuminata reference nuclear genome sequence was recently produced based on sequencing of genomic DNA enriched in nucleus. The Musa acuminata chloroplast genome was assembled with chloroplast reads extracted from whole-genome-shotgun sequence data. The Musa chloroplast genome is a circular molecule of 169,972 bp with a quadripartite structure containing two single copy regions, a Large Single Copy region (LSC, 88,338 bp) and a Small Single Copy region (SSC, 10,768 bp) separated by Inverted Repeat regions (IRs, 35,433 bp). Two forms of the chloroplast genome relative to the orientation of SSC versus LSC were found. The Musa chloroplast genome shows an extreme IR expansion at the IR/SSC boundary relative to the most common structures found in angiosperms. This expansion consists of the integration of three additional complete genes (rps15, ndhH and ycf1) and part of the ndhA gene. No such expansion has been observed in monocots so far. Simple Sequence Repeats were identified in the Musa chloroplast genome and a new set of Musa chloroplastic markers was designed. The complete sequence of M. acuminata ssp malaccensis chloroplast we reported here is the first one for the Zingiberales order. As such it provides new insight in the evolution of the chloroplast of monocotyledons. In particular, it reinforces that IR/SSC expansion has occurred independently several times within monocotyledons. The discovery of new polymorphic markers within Musa chloroplast opens new perspectives to better understand the origin of cultivated triploid bananas.

  11. The complete chloroplast genome of banana (Musa acuminata, Zingiberales: insight into plastid monocotyledon evolution.

    Guillaume Martin

    Full Text Available Banana (genus Musa is a crop of major economic importance worldwide. It is a monocotyledonous member of the Zingiberales, a sister group of the widely studied Poales. Most cultivated bananas are natural Musa inter-(sub-specific triploid hybrids. A Musa acuminata reference nuclear genome sequence was recently produced based on sequencing of genomic DNA enriched in nucleus.The Musa acuminata chloroplast genome was assembled with chloroplast reads extracted from whole-genome-shotgun sequence data. The Musa chloroplast genome is a circular molecule of 169,972 bp with a quadripartite structure containing two single copy regions, a Large Single Copy region (LSC, 88,338 bp and a Small Single Copy region (SSC, 10,768 bp separated by Inverted Repeat regions (IRs, 35,433 bp. Two forms of the chloroplast genome relative to the orientation of SSC versus LSC were found. The Musa chloroplast genome shows an extreme IR expansion at the IR/SSC boundary relative to the most common structures found in angiosperms. This expansion consists of the integration of three additional complete genes (rps15, ndhH and ycf1 and part of the ndhA gene. No such expansion has been observed in monocots so far. Simple Sequence Repeats were identified in the Musa chloroplast genome and a new set of Musa chloroplastic markers was designed.The complete sequence of M. acuminata ssp malaccensis chloroplast we reported here is the first one for the Zingiberales order. As such it provides new insight in the evolution of the chloroplast of monocotyledons. In particular, it reinforces that IR/SSC expansion has occurred independently several times within monocotyledons. The discovery of new polymorphic markers within Musa chloroplast opens new perspectives to better understand the origin of cultivated triploid bananas.

  12. Volatility persistence in crude oil markets

    Charles, Amélie; Darné, Olivier

    2014-01-01

    Financial market participants and policy-makers can benefit from a better understanding of how shocks can affect volatility over time. This study assesses the impact of structural changes and outliers on volatility persistence of three crude oil markets – Brent, West Texas Intermediate (WTI) and Organization of Petroleum Exporting Countries (OPEC) – between January 2, 1985 and June 17, 2011. We identify outliers using a new semi-parametric test based on conditional heteroscedasticity models. These large shocks can be associated with particular event patterns, such as the invasion of Kuwait by Iraq, the Operation Desert Storm, the Operation Desert Fox, and the Global Financial Crisis as well as OPEC announcements on production reduction or US announcements on crude inventories. We show that outliers can bias (i) the estimates of the parameters of the equation governing volatility dynamics; (ii) the regularity and non-negativity conditions of GARCH-type models (GARCH, IGARCH, FIGARCH and HYGARCH); and (iii) the detection of structural breaks in volatility, and thus the estimation of the persistence of the volatility. Therefore, taking into account the outliers on the volatility modelling process may improve the understanding of volatility in crude oil markets. - Highlights: • We study the impact of outliers on volatility persistence of crude oil markets. • We identify outliers and patches of outliers due to specific events. • We show that outliers can bias (i) the estimates of the parameters of GARCH models, (ii) the regularity and non-negativity conditions of GARCH-type models, (iii) the detection of structural breaks in volatility of crude oil markets

  13. Euglena mitochondria and chloroplasts form tyrosine-O-sulfate

    Saidha, T.; Hanfstingl, U.; Schiff, J.A. (Brandeis Univ., Waltham, MA (USA))

    1989-04-01

    Mitochondria from light-grown wild-type Euglena gracilis var. bacillaris Cori or dark-grown mutant W{sub 10}BSmL incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, or with {sup 14}C-tyrosine, non-radioactive sulfate and ATP accumulate a labeled compound in the medium. Since this compound shows exact coelectrophoresis with tyrosine-O-sulfate (TOS) at pH 2.0, 5.8 or 8.0., yields sulfate and tyrosine on acid hydrolysis, and treatment with aryl sulfatase from Aerobacter aerogenes yields sulfate and tyrosine but no tyrosine methyl ester, it is identified as TOS. No TOS is found outside purified developing chloroplasts incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, but both chloroplasts and mitochondria form to {sup 35}S externally when incubated with adenosine 3{prime} phosphate 5{prime}phospho({sup 35}S) sulfate (PAP{sup 35}S). Since no tyrosine need be added, tyrosine is provided from endogenous sources. Although TOS is found in the free pool of Euglena cells it cannot be detected in proteins of cells or mucus ruling our sulfation of tyrosine of protein or incorporation of TOS into proteins. The system forming TOS is membrane-bound and may be involved in tyrosine transport.

  14. Is chloroplastic class IIA aldolase a marine enzyme?

    Miyasaka, Hitoshi; Ogata, Takeru; Tanaka, Satoshi; Ohama, Takeshi; Kano, Sanae; Kazuhiro, Fujiwara; Hayashi, Shuhei; Yamamoto, Shinjiro; Takahashi, Hiro; Matsuura, Hideyuki; Hirata, Kazumasa

    2016-01-01

    Expressed sequence tag analyses revealed that two marine Chlorophyceae green algae, Chlamydomonas sp. W80 and Chlamydomonas sp. HS5, contain genes coding for chloroplastic class IIA aldolase (fructose-1, 6-bisphosphate aldolase: FBA). These genes show robust monophyly with those of the marine Prasinophyceae algae genera Micromonas, Ostreococcus and Bathycoccus, indicating that the acquisition of this gene through horizontal gene transfer by an ancestor of the green algal lineage occurred prior to the divergence of the core chlorophytes (Chlorophyceae and Trebouxiophyceae) and the prasinophytes. The absence of this gene in some freshwater chlorophytes, such as Chlamydomonas reinhardtii, Volvox carteri, Chlorella vulgaris, Chlorella variabilis and Coccomyxa subellipsoidea, can therefore be explained by the loss of this gene somewhere in the evolutionary process. Our survey on the distribution of this gene in genomic and transcriptome databases suggests that this gene occurs almost exclusively in marine algae, with a few exceptions, and as such, we propose that chloroplastic class IIA FBA is a marine environment-adapted enzyme. This hypothesis was also experimentally tested using Chlamydomonas W80, for which we found that the transcript levels of this gene to be significantly lower under low-salt (that is, simulated terrestrial) conditions. Expression analyses of transcriptome data for two algae, Prymnesium parvum and Emiliania huxleyi, taken from the Sequence Read Archive database also indicated that the expression of this gene under terrestrial conditions (low NaCl and low sulfate) is significantly downregulated. Thus, these experimental and transcriptome data provide support for our hypothesis. PMID:27058504

  15. Chloroplast protein synthesis: thylakoid bound polysomes synthesize thylakoid proteins

    Hurewitz, J.; Jagendorf, A.T.

    1986-01-01

    Previous work indicated more polysomes bound to pea thylakoids in light than in the dark, in vivo. With isolated intact chloroplasts incubated in darkness, 24 to 74% more RNA was thylakoid-bound at pH 8.3 than at pH 7. Thus the major effect of light in vivo may be due to higher stroma pH. In isolated pea chloroplasts, initiation inhibitors (pactamycin and kanamycin) decreased the extent of RNA binding, and elongation inhibitors (lincomycin and streptomycin) increased it. Thus translation initiation and termination probably control the cycling of bound ribosomes. While only 3 to 6% of total RNA is in bound polysomes the incorporation of 3 H-Leu into thylakoids was proportional to the amount of this bound RNA. When Micrococcal nuclease-treated thylakoids were added to labeled runoff translation products of stroma ribosomes, less than 1% of the label adhered to the added membranes; but 37% of the labeled products made by thylakoid polysomes were bound. These data support the concept that stroma ribosomes are recruited into thylakoid proteins

  16. The molecular architecture of the chloroplast thylakoid membrane

    Stefansson, H.

    1996-08-01

    Non-detergent procedure for isolation of sub-thylakoid vesicle populations derived from different structural domains of the chloroplast thylakoid membrane has been developed. Sub-thylakoid vesicles representing the grana, grana core, stroma lamellae, and the grana margins have been isolated and their protein composition has been investigated. Furthermore a novel non-detergent procedure for investigating the pigment composition of photosynthetic complexes located in the different structural domains has been developed. This procedure circumvents selective extractions, an perturbing effect often combined with detergent isolations of membrane bound protein complexes. The fractionation experiments show that the NADPH dehydrogenase, suggested to operate as NADPH or ferredoxin-plastoquinone oxidoreductase in cyclic electron transport around photosystem I, is stoichiometrically depleted on photosystem I basis in the grana domain. The fractionation studies are consistent with the model of the thylakoid membrane where the photosystems in the grana are operating in a linear electron transport whereas the site of cyclic electron transport is in the stroma lamellae. It is suggested that partial destacking of grana, as a result of light-induced protein phosphorylation, may promote the exposure of the granal photosystem I centers to the chloroplast stroma and thereby enhance their participation in cyclic electron transport activity. 146 refs, 18 figs

  17. Systemic toxicity of dermally applied crude oils in rats

    Feuston, M.H.; Mackerer, C.R.; Schreiner, C.A.; Hamilton, C.E. [Stonybrook Labs., Inc., Princeton, NJ (United States)

    1997-12-31

    Two crude oils, differing in viscosity (V) and nitrogen (N) and sulfur (S) content, were evaluated for systemic toxicity, In the Crude I (low V, low N, low S) study, the material was applied to the clipped backs of rats at dose levels of 0, 30, 125, and 500 mg/kg. In the Crude II (high V, high N, moderate S) study, the oil was applied similarly at the same dose levels. The crude oils were applied for 13 wk, 5 d/wk. Exposure sites were not occluded. Mean body weight gain (wk 1-14) was significantly reduced in male rats exposed to Crude II; body weight gain of all other animals was not adversely affected by treatment. An increase in absolute (A) and relative (R) liver weights and a decrease in A and R thymus weights were observed in male and female rats exposed to Crude II at 500 mg/kg; only liver weights (A and R) were adversely affected in male and female rats exposed to Crude I. In general, there was no consistent pattern of toxicity for serum chemistry endpoints; however, more parameters were adversely affected in Crude II-exposed female rats than in the other exposed groups. A consistent pattern of toxicity for hematology endpoints was observed among male rats exposed to Crude I and male and female rats exposed to Crude II. Parameters affected included: Crudes I and II, red blood cell count, hemoglobin, and hematocrit, Crude II, platelet count. Microscopic evaluation of tissues revealed the following treatment-related findings: Crude I, treated skin, thymus, and thyroid; Crude II, bone marrow, treated skin, thymus, and thyroid. The LOEL (lowest observable effect level) for skin irritation and systemic toxicity (based on marginal effects on the thyroid) for both crude oils was 30 mg/kg; effects were more numerous and more pronounced in animals exposed to Crude II. Systemic effects are probably related to concentrations of polycyclic aromatic compounds (PAC) found in crude oil.

  18. Carbon dioxide diffusion across stomata and mesophyll and photo-biochemical processes as affected by growth CO2 and phosphorus nutrition in cotton.

    Singh, Shardendu K; Badgujar, Girish; Reddy, Vangimalla R; Fleisher, David H; Bunce, James A

    2013-06-15

    Nutrients such as phosphorus may exert a major control over plant response to rising atmospheric carbon dioxide concentration (CO2), which is projected to double by the end of the 21st century. Elevated CO2 may overcome the diffusional limitations to photosynthesis posed by stomata and mesophyll and alter the photo-biochemical limitations resulting from phosphorus deficiency. To evaluate these ideas, cotton (Gossypium hirsutum) was grown in controlled environment growth chambers with three levels of phosphate (Pi) supply (0.2, 0.05 and 0.01mM) and two levels of CO2 concentration (ambient 400 and elevated 800μmolmol(-1)) under optimum temperature and irrigation. Phosphate deficiency drastically inhibited photosynthetic characteristics and decreased cotton growth for both CO2 treatments. Under Pi stress, an apparent limitation to the photosynthetic potential was evident by CO2 diffusion through stomata and mesophyll, impairment of photosystem functioning and inhibition of biochemical process including the carboxylation efficiency of ribulose-1,5-bisphosphate carboxylase/oxyganase and the rate of ribulose-1,5-bisphosphate regeneration. The diffusional limitation posed by mesophyll was up to 58% greater than the limitation due to stomatal conductance (gs) under Pi stress. As expected, elevated CO2 reduced these diffusional limitations to photosynthesis across Pi levels; however, it failed to reduce the photo-biochemical limitations to photosynthesis in phosphorus deficient plants. Acclimation/down regulation of photosynthetic capacity was evident under elevated CO2 across Pi treatments. Despite a decrease in phosphorus, nitrogen and chlorophyll concentrations in leaf tissue and reduced stomatal conductance at elevated CO2, the rate of photosynthesis per unit leaf area when measured at the growth CO2 concentration tended to be higher for all except the lowest Pi treatment. Nevertheless, plant biomass increased at elevated CO2 across Pi nutrition with taller plants

  19. Structural characterization of a mixed-linkage glucan deficient mutant reveals alteration in cellulose microfibril orientation in rice coleoptile mesophyll cell walls

    Andreia Michelle Smith-Moritz

    2015-08-01

    Full Text Available The CELLULOSE SYNTHASE-LIKE F6 (CslF6 gene was previously shown to mediate the biosynthesis of mixed-linkage glucan (MLG, a cell wall polysaccharide that is hypothesized to be a tightly associated with cellulose and also have a role in cell expansion in the primary cell wall of young seedlings in grass species. We have recently shown that loss-of-function cslf6 rice mutants do not accumulate MLG in most vegetative tissues. Despite the absence of a structurally important polymer, MLG, these mutants are unexpectedly viable and only show a moderate growth compromise compared to wild type. Therefore these mutants are ideal biological systems to test the current grass cell wall model. In order to gain a better understanding of the role of MLG in the primary wall, we performed in-depth compositional and structural analyses of the cell walls of three day-old rice seedlings using various biochemical and novel microspectroscopic approaches. We found that cellulose content as well as matrix polysaccharide composition was not significantly altered in the MLG deficient mutant. However, we observed a significant change in cellulose microfibril bundle organization in mesophyll cell walls of the cslf6 mutant. Using synchrotron source Fourier Transform Mid-Infrared Spectromicroscopy for high-resolution imaging, we determined that the bonds associated with cellulose and arabinoxylan, another major component of the primary cell was of grasses, were in a lower energy configuration compared to wild type, suggesting a slightly weaker primary wall in MLG deficient mesophyll cells. Taken together, these results suggest that MLG may influence cellulose deposition in mesophyll cell walls without significantly affecting anisotropic growth thus challenging MLG importance in cell wall expansion.

  20. Application of Markov Model in Crude Oil Price Forecasting

    Nuhu Isah

    2017-08-01

    Full Text Available Crude oil is an important energy commodity to mankind. Several causes have made crude oil prices to be volatile. The fluctuation of crude oil prices has affected many related sectors and stock market indices. Hence, forecasting the crude oil prices is essential to avoid the future prices of the non-renewable natural resources to rise. In this study, daily crude oil prices data was obtained from WTI dated 2 January to 29 May 2015. We used Markov Model (MM approach in forecasting the crude oil prices. In this study, the analyses were done using EViews and Maple software where the potential of this software in forecasting daily crude oil prices time series data was explored. Based on the study, we concluded that MM model is able to produce accurate forecast based on a description of history patterns in crude oil prices.

  1. Assessment of Antioxidant Indices after incorporating Crude Oil ...

    ADOWIE PERE

    Exposure to crude oil pollution leads to the formation ... vitamin/mineral mixture (5 %). The food ..... hepatic antioxidant enzymes against cadmium induced liver ... Interaction of crude oil with alpha-tocopherol: ... Essential oil from Monodora.

  2. A MODEL FOR DIFFUSION CONTROLLED BIOAVAILABILITY OF CRUDE OIL COMPONENTS

    Crude oil is a complex mixture of several different structural classes of compounds including alkanes, aromatics, heterocyclic polar compounds, and asphaltenes. The rate and extent of microbial degradation of crude oil depends on the interaction between the physical and biochemi...

  3. Characterization of CRUDE OILS and petroleum products: (i) elution ...

    Characterization of CRUDE OILS and petroleum products: (i) elution liquid chromatographic separation and gas chromatographic analysis of crude oils and petroleum products. E.O. Odebunmi, E.A. Ogunsakin, P.E.P. Ilukhor ...

  4. The role of mesophyll conductance during water stress and recovery in tobacco (Nicotiana sylvestris): acclimation or limitation?

    Galle, Alexander; Florez-Sarasa, Igor; Tomas, Magdalena; Pou, Alicia; Medrano, Hipolito; Ribas-Carbo, Miquel; Flexas, Jaume

    2009-01-01

    While the responses of photosynthesis to water stress have been widely studied, acclimation to sustained water stress and recovery after re-watering is poorly understood. In particular, the factors limiting photosynthesis under these conditions, and their possible interactions with other environmental conditions, are unknown. To assess these issues, changes of photosynthetic CO(2) assimilation (A(N)) and its underlying limitations were followed during prolonged water stress and subsequent re-watering in tobacco (Nicotiana sylvestris) plants growing under three different climatic conditions: outdoors in summer, outdoors in spring, and indoors in a growth chamber. In particular, the regulation of stomatal conductance (g(s)), mesophyll conductance to CO(2) (g(m)), leaf photochemistry (chlorophyll fluorescence), and biochemistry (V(c,max)) were assessed. Leaf gas exchange and chlorophyll fluorescence data revealed that water stress induced a similar degree of stomatal closure and decreased A(N) under all three conditions, while V(c,max) was unaffected. However, the behaviour of g(m) differed depending on the climatic conditions. In outdoor plants, g(m) strongly declined with water stress, but it recovered rapidly (1-2 d) after re-watering in spring while it remained low many days after re-watering in summer. In indoor plants, g(m) initially declined with water stress, but then recovered to control values during the acclimation period. These differences were reflected in different velocities of recovery of A(N) after re-watering, being the slowest in outdoor summer plants and the fastest in indoor plants. It is suggested that these differences among the experiments are related to the prevailing climatic conditions, i.e. to the fact that stress factors other than water stress have been superimposed (e.g. excessive light and elevated temperature). In conclusion, besides g(s), g(m) contributes greatly to the limitation of photosynthesis during water stress and during

  5. Cell wall matrix polysaccharide distribution and cortical microtubule organization: two factors controlling mesophyll cell morphogenesis in land plants.

    Sotiriou, P; Giannoutsou, E; Panteris, E; Apostolakos, P; Galatis, B

    2016-03-01

    This work investigates the involvement of local differentiation of cell wall matrix polysaccharides and the role of microtubules in the morphogenesis of mesophyll cells (MCs) of three types (lobed, branched and palisade) in the dicotyledon Vigna sinensis and the fern Asplenium nidus. Homogalacturonan (HGA) epitopes recognized by the 2F4, JIM5 and JIM7 antibodies and callose were immunolocalized in hand-made leaf sections. Callose was also stained with aniline blue. We studied microtubule organization by tubulin immunofluorescence and transmission electron microscopy. In both plants, the matrix cell wall polysaccharide distribution underwent definite changes during MC differentiation. Callose constantly defined the sites of MC contacts. The 2F4 HGA epitope in V. sinensis first appeared in MC contacts but gradually moved towards the cell wall regions facing the intercellular spaces, while in A. nidus it was initially localized at the cell walls delimiting the intercellular spaces, but finally shifted to MC contacts. In V. sinensis, the JIM5 and JIM7 HGA epitopes initially marked the cell walls delimiting the intercellular spaces and gradually shifted in MC contacts, while in A. nidus they constantly enriched MC contacts. In all MC types examined, the cortical microtubules played a crucial role in their morphogenesis. In particular, in palisade MCs, cortical microtubule helices, by controlling cellulose microfibril orientation, forced these MCs to acquire a truncated cone-like shape. Unexpectedly in V. sinensis, the differentiation of colchicine-affected MCs deviated completely, since they developed a cell wall ingrowth labyrinth, becoming transfer-like cells. The results of this work and previous studies on Zea mays (Giannoutsou et al., Annals of Botany 2013; 112: : 1067-1081) revealed highly controlled local cell wall matrix differentiation in MCs of species belonging to different plant groups. This, in coordination with microtubule-dependent cellulose microfibril

  6. Chloroplast-expressed MSI-99 in tobacco improves disease resistance and displays inhibitory effect against rice blast fungus.

    Wang, Yun-Peng; Wei, Zheng-Yi; Zhang, Yu-Ying; Lin, Chun-Jing; Zhong, Xiao-Fang; Wang, Yue-Lin; Ma, Jing-Yong; Ma, Jian; Xing, Shao-Chen

    2015-03-02

    Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

  7. Induction of neutralizing antibodies by a tobacco chloroplast-derived vaccine based on a B cell epitope from canine parvovirus.

    Molina, Andrea; Veramendi, Jon; Hervás-Stubbs, Sandra

    2005-11-25

    The 2L21 epitope of the VP2 protein from the canine parvovirus (CPV), fused to the cholera toxin B subunit (CTB-2L21), was expressed in transgenic tobacco chloroplasts. Mice and rabbits that received protein-enriched leaf extracts by parenteral route produced high titers of anti-2L21 antibodies able to recognize the VP2 protein. Rabbit sera were able to neutralize CPV in an in vitro infection assay with an efficacy similar to the anti-2L21 neutralizing monoclonal antibody 3C9. Anti-2L21 IgG and seric IgA antibodies were elicited when mice were gavaged with a suspension of pulverized tissues from CTB-2L21 transformed plants. Combined immunization (a single parenteral injection followed by oral boosters) shows that oral boosters help to maintain the anti-2L21 IgG response induced after a single injection, whereas parenteral administration of the antigen primes the subsequent oral boosters by promoting the induction of anti-2L21 seric IgA antibodies. Despite the induced humoral response, antibodies elicited by oral delivery did not show neutralizing capacity in the in vitro assay. The high yield of the fusion protein permits the preparation of a high number of vaccine doses from a single plant and makes feasible the oral vaccination using a small amount of crude plant material. However, a big effort has still to be done to enhance the protective efficacy of subunit vaccines by the oral route.

  8. Induction of neutralizing antibodies by a tobacco chloroplast-derived vaccine based on a B cell epitope from canine parvovirus

    Molina, Andrea; Veramendi, Jon; Hervas-Stubbs, Sandra

    2005-01-01

    The 2L21 epitope of the VP2 protein from the canine parvovirus (CPV), fused to the cholera toxin B subunit (CTB-2L21), was expressed in transgenic tobacco chloroplasts. Mice and rabbits that received protein-enriched leaf extracts by parenteral route produced high titers of anti-2L21 antibodies able to recognize the VP2 protein. Rabbit sera were able to neutralize CPV in an in vitro infection assay with an efficacy similar to the anti-2L21 neutralizing monoclonal antibody 3C9. Anti-2L21 IgG and seric IgA antibodies were elicited when mice were gavaged with a suspension of pulverized tissues from CTB-2L21 transformed plants. Combined immunization (a single parenteral injection followed by oral boosters) shows that oral boosters help to maintain the anti-2L21 IgG response induced after a single injection, whereas parenteral administration of the antigen primes the subsequent oral boosters by promoting the induction of anti-2L21 seric IgA antibodies. Despite the induced humoral response, antibodies elicited by oral delivery did not show neutralizing capacity in the in vitro assay. The high yield of the fusion protein permits the preparation of a high number of vaccine doses from a single plant and makes feasible the oral vaccination using a small amount of crude plant material. However, a big effort has still to be done to enhance the protective efficacy of subunit vaccines by the oral route

  9. Chloroplast-Expressed MSI-99 in Tobacco Improves Disease Resistance and Displays Inhibitory Effect against Rice Blast Fungus

    Yun-Peng Wang

    2015-03-01

    Full Text Available Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

  10. The complete chloroplast genome sequence of Helwingia himalaica (Helwingiaceae, Aquifoliales) and a chloroplast phylogenomic analysis of the Campanulidae.

    Yao, Xin; Liu, Ying-Ying; Tan, Yun-Hong; Song, Yu; Corlett, Richard T

    2016-01-01

    Complete chloroplast genome sequences have been very useful for understanding phylogenetic relationships in angiosperms at the family level and above, but there are currently large gaps in coverage. We report the chloroplast genome for Helwingia himalaica , the first in the distinctive family Helwingiaceae and only the second genus to be sequenced in the order Aquifoliales. We then combine this with 36 published sequences in the large (c. 35,000 species) subclass Campanulidae in order to investigate relationships at the order and family levels. The Helwingia genome consists of 158,362 bp containing a pair of inverted repeat (IR) regions of 25,996 bp separated by a large single-copy (LSC) region and a small single-copy (SSC) region which are 87,810 and 18,560 bp, respectively. There are 142 known genes, including 94 protein-coding genes, eight ribosomal RNA genes, and 40 tRNA genes. The topology of the phylogenetic relationships between Apiales, Asterales, and Dipsacales differed between analyses based on complete genome sequences and on 36 shared protein-coding genes, showing that further studies of campanulid phylogeny are needed.

  11. The complete chloroplast genome sequence of Helwingia himalaica (Helwingiaceae, Aquifoliales and a chloroplast phylogenomic analysis of the Campanulidae

    Xin Yao

    2016-11-01

    Full Text Available Complete chloroplast genome sequences have been very useful for understanding phylogenetic relationships in angiosperms at the family level and above, but there are currently large gaps in coverage. We report the chloroplast genome for Helwingia himalaica, the first in the distinctive family Helwingiaceae and only the second genus to be sequenced in the order Aquifoliales. We then combine this with 36 published sequences in the large (c. 35,000 species subclass Campanulidae in order to investigate relationships at the order and family levels. The Helwingia genome consists of 158,362 bp containing a pair of inverted repeat (IR regions of 25,996 bp separated by a large single-copy (LSC region and a small single-copy (SSC region which are 87,810 and 18,560 bp, respectively. There are 142 known genes, including 94 protein-coding genes, eight ribosomal RNA genes, and 40 tRNA genes. The topology of the phylogenetic relationships between Apiales, Asterales, and Dipsacales differed between analyses based on complete genome sequences and on 36 shared protein-coding genes, showing that further studies of campanulid phylogeny are needed.

  12. Molluscicidal activity of crude water leaf extracts of Alternanthera ...

    mortality figures by the use of probit gave LC50 of 40.42 (35.15 – 46.47) for the unevaporated crude water while the evaporated crude water extract had LC50 of 48.07 (42.81 – 54.28) for the dried leaf extract. For the fresh leaves the unevaporated crude water extract had LC50 of 32.57 (27.15 – 39.08) and evaporated crude ...

  13. Chloroplast Translation: Structural and Functional Organization, Operational Control, and Regulation[OPEN

    2018-01-01

    Chloroplast translation is essential for cellular viability and plant development. Its positioning at the intersection of organellar RNA and protein metabolism makes it a unique point for the regulation of gene expression in response to internal and external cues. Recently obtained high-resolution structures of plastid ribosomes, the development of approaches allowing genome-wide analyses of chloroplast translation (i.e., ribosome profiling), and the discovery of RNA binding proteins involved in the control of translational activity have greatly increased our understanding of the chloroplast translation process and its regulation. In this review, we provide an overview of the current knowledge of the chloroplast translation machinery, its structure, organization, and function. In addition, we summarize the techniques that are currently available to study chloroplast translation and describe how translational activity is controlled and which cis-elements and trans-factors are involved. Finally, we discuss how translational control contributes to the regulation of chloroplast gene expression in response to developmental, environmental, and physiological cues. We also illustrate the commonalities and the differences between the chloroplast and bacterial translation machineries and the mechanisms of protein biosynthesis in these two prokaryotic systems. PMID:29610211

  14. The chloroplast genome of a symbiodinium sp. clade C3 isolate

    Barbrook, Adrian C.

    2014-01-01

    Dinoflagellate algae of the genus Symbiodinium form important symbioses within corals and other benthic marine animals. Dinoflagellates possess an extremely reduced plastid genome relative to those examined in plants and other algae. In dinoflagellates the plastid genes are located on small plasmids, commonly referred to as \\'minicircles\\'. However, the chloroplast genomes of dinoflagellates have only been extensively characterised from a handful of species. There is also evidence of considerable variation in the chloroplast genome organisation across those species that have been examined. We therefore characterised the chloroplast genome from an environmental coral isolate, in this case containing a symbiont belonging to the Symbiodinium sp. clade C3. The gene content of the genome is well conserved with respect to previously characterised genomes. However, unlike previously characterised dinoflagellate chloroplast genomes we did not identify any \\'empty\\' minicircles. The sequences of this chloroplast genome show a high rate of evolution relative to other algal species. Particularly notable was a surprisingly high level of sequence divergence within the core polypeptides of photosystem I, the reasons for which are currently unknown. This chloroplast genome also possesses distinctive codon usage and GC content. These features suggest that chloroplast genomes in Symbiodinium are highly plastic. © 2013 Adrian C. Barbrook.

  15. Chloroplast two-component systems: evolution of the link between photosynthesis and gene expression.

    Puthiyaveetil, Sujith; Allen, John F

    2009-06-22

    Two-component signal transduction, consisting of sensor kinases and response regulators, is the predominant signalling mechanism in bacteria. This signalling system originated in prokaryotes and has spread throughout the eukaryotic domain of life through endosymbiotic, lateral gene transfer from the bacterial ancestors and early evolutionary precursors of eukaryotic, cytoplasmic, bioenergetic organelles-chloroplasts and mitochondria. Until recently, it was thought that two-component systems inherited from an ancestral cyanobacterial symbiont are no longer present in chloroplasts. Recent research now shows that two-component systems have survived in chloroplasts as products of both chloroplast and nuclear genes. Comparative genomic analysis of photosynthetic eukaryotes shows a lineage-specific distribution of chloroplast two-component systems. The components and the systems they comprise have homologues in extant cyanobacterial lineages, indicating their ancient cyanobacterial origin. Sequence and functional characteristics of chloroplast two-component systems point to their fundamental role in linking photosynthesis with gene expression. We propose that two-component systems provide a coupling between photosynthesis and gene expression that serves to retain genes in chloroplasts, thus providing the basis of cytoplasmic, non-Mendelian inheritance of plastid-associated characters. We discuss the role of this coupling in the chronobiology of cells and in the dialogue between nuclear and cytoplasmic genetic systems.

  16. Structure-Function Analysis of Chloroplast Proteins via Random Mutagenesis Using Error-Prone PCR.

    Dumas, Louis; Zito, Francesca; Auroy, Pascaline; Johnson, Xenie; Peltier, Gilles; Alric, Jean

    2018-06-01

    Site-directed mutagenesis of chloroplast genes was developed three decades ago and has greatly advanced the field of photosynthesis research. Here, we describe a new approach for generating random chloroplast gene mutants that combines error-prone polymerase chain reaction of a gene of interest with chloroplast complementation of the knockout Chlamydomonas reinhardtii mutant. As a proof of concept, we targeted a 300-bp sequence of the petD gene that encodes subunit IV of the thylakoid membrane-bound cytochrome b 6 f complex. By sequencing chloroplast transformants, we revealed 149 mutations in the 300-bp target petD sequence that resulted in 92 amino acid substitutions in the 100-residue target subunit IV sequence. Our results show that this method is suited to the study of highly hydrophobic, multisubunit, and chloroplast-encoded proteins containing cofactors such as hemes, iron-sulfur clusters, and chlorophyll pigments. Moreover, we show that mutant screening and sequencing can be used to study photosynthetic mechanisms or to probe the mutational robustness of chloroplast-encoded proteins, and we propose that this method is a valuable tool for the directed evolution of enzymes in the chloroplast. © 2018 American Society of Plant Biologists. All rights reserved.

  17. Functional Disruption of a Chloroplast Pseudouridine Synthase Desensitizes Arabidopsis Plants to Phosphate Starvation

    Shan Lu

    2017-08-01

    Full Text Available Phosphate (Pi deficiency is a common nutritional stress of plants in both agricultural and natural ecosystems. Plants respond to Pi starvation in the environment by triggering a suite of biochemical, physiological, and developmental changes that increase survival and growth. The key factors that determine plant sensitivity to Pi starvation, however, are unclear. In this research, we identified an Arabidopsis mutant, dps1, with greatly reduced sensitivity to Pi starvation. The dps1 phenotypes are caused by a mutation in the previously characterized SVR1 (SUPPRESSION OF VARIAGATION 1 gene, which encodes a chloroplast-localized pseudouridine synthase. The mutation of SVR1 results in defects in chloroplast rRNA biogenesis, which subsequently reduces chloroplast translation. Another mutant, rps5, which contains a mutation in the chloroplast ribosomal protein RPS5 and has reduced chloroplast translation, also displayed decreased sensitivity to Pi starvation. Furthermore, wild type plants treated with lincomycin, a chemical inhibitor of chloroplast translation, showed similar growth phenotypes and Pi starvation responses as dps1 and rps5. These results suggest that impaired chloroplast translation desensitizes plants to Pi starvation. Combined with previously published results showing that enhanced leaf photosynthesis augments plant responses to Pi starvation, we propose that the decrease in responses to Pi starvation in dps1, rps5, and lincomycin-treated plants is due to their reduced demand for Pi input from the environment.

  18. The chloroplast genome of a symbiodinium sp. clade C3 isolate

    Barbrook, Adrian C.; Voolstra, Christian R.; Howe, Christopher J.

    2014-01-01

    Dinoflagellate algae of the genus Symbiodinium form important symbioses within corals and other benthic marine animals. Dinoflagellates possess an extremely reduced plastid genome relative to those examined in plants and other algae. In dinoflagellates the plastid genes are located on small plasmids, commonly referred to as 'minicircles'. However, the chloroplast genomes of dinoflagellates have only been extensively characterised from a handful of species. There is also evidence of considerable variation in the chloroplast genome organisation across those species that have been examined. We therefore characterised the chloroplast genome from an environmental coral isolate, in this case containing a symbiont belonging to the Symbiodinium sp. clade C3. The gene content of the genome is well conserved with respect to previously characterised genomes. However, unlike previously characterised dinoflagellate chloroplast genomes we did not identify any 'empty' minicircles. The sequences of this chloroplast genome show a high rate of evolution relative to other algal species. Particularly notable was a surprisingly high level of sequence divergence within the core polypeptides of photosystem I, the reasons for which are currently unknown. This chloroplast genome also possesses distinctive codon usage and GC content. These features suggest that chloroplast genomes in Symbiodinium are highly plastic. © 2013 Adrian C. Barbrook.

  19. Cadmium Disrupts Subcellular Organelles, Including Chloroplasts, Resulting in Melatonin Induction in Plants

    Hyoung-Yool Lee

    2017-10-01

    Full Text Available Cadmium is a well-known elicitor of melatonin synthesis in plants, including rice. However, the mechanisms by which cadmium induces melatonin induction remain elusive. To investigate whether cadmium influences physical integrities in subcellular organelles, we treated tobacco leaves with either CdCl2 or AlCl3 and monitored the structures of subcellular organelles—such as chloroplasts, mitochondria, and the endoplasmic reticulum (ER—using confocal microscopic analysis. Unlike AlCl3 treatment, CdCl2 (0.5 mM treatment significantly disrupted chloroplasts, mitochondria, and ER. In theory, the disruption of chloroplasts enabled chloroplast-expressed serotonin N-acetyltransferase (SNAT to encounter serotonin in the cytoplasm, leading to the synthesis of N-acetylserotonin followed by melatonin synthesis. In fact, the disruption of chloroplasts by cadmium, not by aluminum, gave rise to a huge induction of melatonin in rice leaves, which suggests that cadmium-treated chloroplast disruption plays an important role in inducing melatonin in plants by removing physical barriers, such as chloroplast double membranes, allowing SNAT to gain access to the serotonin substrate enriched in the cytoplasm.

  20. Dated tribe-wide whole chloroplast genome phylogeny indicates recurrent hybridizations within Triticeae.

    Bernhardt, Nadine; Brassac, Jonathan; Kilian, Benjamin; Blattner, Frank R

    2017-06-16

    Triticeae, the tribe of wheat grasses, harbours the cereals barley, rye and wheat and their wild relatives. Although economically important, relationships within the tribe are still not understood. We analysed the phylogeny of chloroplast lineages among nearly all monogenomic Triticeae taxa and polyploid wheat species aiming at a deeper understanding of the tribe's evolution. We used on- and off-target reads of a target-enrichment experiment followed by Illumina sequencing. The read data was used to assemble the plastid locus ndhF for 194 individuals and the whole chloroplast genome for 183 individuals, representing 53 Triticeae species and 15 genera. We conducted Bayesian and multispecies coalescent analyses to infer relationships and estimate divergence times of the taxa. We present the most comprehensive dated Triticeae chloroplast phylogeny and review previous hypotheses in the framework of our results. Monophyly of Triticeae chloroplasts could not be confirmed, as either Bromus or Psathyrostachys captured a chloroplast from a lineage closely related to a Bromus-Triticeae ancestor. The most recent common ancestor of Triticeae occurred approximately between ten and 19 million years ago. The comparison of the chloroplast phylogeny with available nuclear data in several cases revealed incongruences indicating past hybridizations. Recent events of chloroplast capture were detected as individuals grouped apart from con-specific accessions in otherwise monopyhletic groups.

  1. Lactic acid fermentation of crude sorghum extract

    Samuel, W.A.; Lee, Y.Y.; Anthony, W.B.

    1980-04-01

    Crude extract from sweet sorghum supplemented with vetch juice was utilized as the carbohydrate source for fermentative production of lactic acid. Fermentation of media containing 7% (w/v) total sugar was completed in 60-80 hours by Lactobacillus plantarum, product yield averaging 85%. Maximum acid production rates were dependent on pH, initial substrate distribution, and concentration, the rates varying from 2 to 5 g/liter per hour. Under limited medium supplementation the lactic acid yield was lowered to 67%. The fermented ammoniated product contained over eight times as much equivalent crude protein (N x 6.25) as the original medium. Unstructured kinetic models were developed for cell growth, lactic acid formation, and substrate consumption in batch fermentation. With the provision of experimentally determined kinetic parameters, the proposed models accurately described the fermentation process. 15 references.

  2. Tanker spills Norwegian crude oil off Shetlands

    Anon.

    1993-01-01

    This paper reports that crude oil was spilling last week from the U.S. owned Braer tanker after the 89,000 dwt vessel ran aground on the south end of Scotland's Shetland Islands. Workers were trying to assess the extent of damage to the tanker, shoreline, and wildlife after the January 5 accident. Braer's cargo amounted to 607,000 bbl of Norwegian oil bound for Canada. Braer loaded its cargo and sailed January 3 from Den norske stats oljeselskap AS's Mongstad, Norway, terminal with crude from Gullfaks field in the Norwegian North Sea. The $11 million shipment was destined for Ultramar Canada Inc.'s 125,000 b/d refinery at St. Romuald, Que

  3. Electrical desalting - preparing of the crude oil for further processing

    Asadi, Nadija; Minovski, Mino; Sokolovski, Aleksandar

    1999-01-01

    Desalting as well as dewatering of the crude oil is important preparing process, which takes place in crude units on the refinery plants. One of the most efficient ways of desalting is use of high voltage electricity. In this work attention is paid on the principals of this process, illustrated with practically gained results from the OKTA Crude Oil Refinery in Macedonia. (Original)

  4. Bioremediation of crude oil contaminated tea plantation soil using ...

    Crude oil contamination of soil is a major concern for tea industry in Assam, India. Crude oil is a persistent organic contaminant which alters soil physical and biochemical characteristics and makes tea plants more susceptible against crude oil contamination. Therefore, two native bacterial strains designated as AS 03 and ...

  5. 10 CFR 212.78 - Tertiary incentive crude oil.

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Tertiary incentive crude oil. 212.78 Section 212.78 Energy DEPARTMENT OF ENERGY OIL MANDATORY PETROLEUM PRICE REGULATIONS Producers of Crude Oil § 212.78 Tertiary incentive crude oil. Annual prepaid expenses report. By January 31 of each year after 1980, the project...

  6. Complete sequencing of five araliaceae chloroplast genomes and the phylogenetic implications.

    Rong Li

    Full Text Available BACKGROUND: The ginseng family (Araliaceae includes a number of economically important plant species. Previously phylogenetic studies circumscribed three major clades within the core ginseng plant family, yet the internal relationships of each major group have been poorly resolved perhaps due to rapid radiation of these lineages. Recent studies have shown that phyogenomics based on chloroplast genomes provides a viable way to resolve complex relationships. METHODOLOGY/PRINCIPAL FINDINGS: We report the complete nucleotide sequences of five Araliaceae chloroplast genomes using next-generation sequencing technology. The five chloroplast genomes are 156,333-156,459 bp in length including a pair of inverted repeats (25,551-26,108 bp separated by the large single-copy (86,028-86,566 bp and small single-copy (18,021-19,117 bp regions. Each chloroplast genome contains the same 114 unique genes consisting of 30 transfer RNA genes, four ribosomal RNA genes, and 80 protein coding genes. Gene size, content, and order, AT content, and IR/SC boundary structure are similar among all Araliaceae chloroplast genomes. A total of 140 repeats were identified in the five chloroplast genomes with palindromic repeat as the most common type. Phylogenomic analyses using parsimony, likelihood, and Bayesian inference based on the complete chloroplast genomes strongly supported the monophyly of the Asian Palmate group and the Aralia-Panax group. Furthermore, the relationships among the sampled taxa within the Asian Palmate group were well resolved. Twenty-six DNA markers with the percentage of variable sites higher than 5% were identified, which may be useful for phylogenetic studies of Araliaceae. CONCLUSION: The chloroplast genomes of Araliaceae are highly conserved in all aspects of genome features. The large-scale phylogenomic data based on the complete chloroplast DNA sequences is shown to be effective for the phylogenetic reconstruction of Araliaceae.

  7. Combined analysis of the chloroplast genome and transcriptome of the Antarctic vascular plant Deschampsia antarctica Desv.

    Lee, Jungeun; Kang, Yoonjee; Shin, Seung Chul; Park, Hyun; Lee, Hyoungseok

    2014-01-01

    Antarctic hairgrass (Deschampsia antarctica Desv.) is the only natural grass species in the maritime Antarctic. It has been researched as an important ecological marker and as an extremophile plant for studies on stress tolerance. Despite its importance, little genomic information is available for D. antarctica. Here, we report the complete chloroplast genome, transcriptome profiles of the coding/noncoding genes, and the posttranscriptional processing by RNA editing in the chloroplast system. The complete chloroplast genome of D. antarctica is 135,362 bp in length with a typical quadripartite structure, including the large (LSC: 79,881 bp) and small (SSC: 12,519 bp) single-copy regions, separated by a pair of identical inverted repeats (IR: 21,481 bp). It contains 114 unique genes, including 81 unique protein-coding genes, 29 tRNA genes, and 4 rRNA genes. Sequence divergence analysis with other plastomes from the BEP clade of the grass family suggests a sister relationship between D. antarctica, Festuca arundinacea and Lolium perenne of the Poeae tribe, based on the whole plastome. In addition, we conducted high-resolution mapping of the chloroplast-derived transcripts. Thus, we created an expression profile for 81 protein-coding genes and identified ndhC, psbJ, rps19, psaJ, and psbA as the most highly expressed chloroplast genes. Small RNA-seq analysis identified 27 small noncoding RNAs of chloroplast origin that were preferentially located near the 5'- or 3'-ends of genes. We also found >30 RNA-editing sites in the D. antarctica chloroplast genome, with a dominance of C-to-U conversions. We assembled and characterized the complete chloroplast genome sequence of D. antarctica and investigated the features of the plastid transcriptome. These data may contribute to a better understanding of the evolution of D. antarctica within the Poaceae family for use in molecular phylogenetic studies and may also help researchers understand the characteristics of the chloroplast

  8. Transcriptome analysis of ectopic chloroplast development in green curd cauliflower (Brassica oleracea L. var. botrytis

    Zhou Xiangjun

    2011-11-01

    Full Text Available Abstract Background Chloroplasts are the green plastids where photosynthesis takes place. The biogenesis of chloroplasts requires the coordinate expression of both nuclear and chloroplast genes and is regulated by developmental and environmental signals. Despite extensive studies of this process, the genetic basis and the regulatory control of chloroplast biogenesis and development remain to be elucidated. Results Green cauliflower mutant causes ectopic development of chloroplasts in the curd tissue of the plant, turning the otherwise white curd green. To investigate the transcriptional control of chloroplast development, we compared gene expression between green and white curds using the RNA-seq approach. Deep sequencing produced over 15 million reads with lengths of 86 base pairs from each cDNA library. A total of 7,155 genes were found to exhibit at least 3-fold changes in expression between green and white curds. These included light-regulated genes, genes encoding chloroplast constituents, and genes involved in chlorophyll biosynthesis. Moreover, we discovered that the cauliflower ELONGATED HYPOCOTYL5 (BoHY5 was expressed higher in green curds than white curds and that 2616 HY5-targeted genes, including 1600 up-regulated genes and 1016 down-regulated genes, were differently expressed in green in comparison to white curd tissue. All these 1600 up-regulated genes were HY5-targeted genes in the light. Conclusions The genome-wide profiling of gene expression by RNA-seq in green curds led to the identification of large numbers of genes associated with chloroplast development, and suggested the role of regulatory genes in the high hierarchy of light signaling pathways in mediating the ectopic chloroplast development in the green curd cauliflower mutant.

  9. Transcriptome analysis of ectopic chloroplast development in green curd cauliflower (Brassica oleracea L. var. botrytis).

    Zhou, Xiangjun; Fei, Zhangjun; Thannhauser, Theodore W; Li, Li

    2011-11-23

    Chloroplasts are the green plastids where photosynthesis takes place. The biogenesis of chloroplasts requires the coordinate expression of both nuclear and chloroplast genes and is regulated by developmental and environmental signals. Despite extensive studies of this process, the genetic basis and the regulatory control of chloroplast biogenesis and development remain to be elucidated. Green cauliflower mutant causes ectopic development of chloroplasts in the curd tissue of the plant, turning the otherwise white curd green. To investigate the transcriptional control of chloroplast development, we compared gene expression between green and white curds using the RNA-seq approach. Deep sequencing produced over 15 million reads with lengths of 86 base pairs from each cDNA library. A total of 7,155 genes were found to exhibit at least 3-fold changes in expression between green and white curds. These included light-regulated genes, genes encoding chloroplast constituents, and genes involved in chlorophyll biosynthesis. Moreover, we discovered that the cauliflower ELONGATED HYPOCOTYL5 (BoHY5) was expressed higher in green curds than white curds and that 2616 HY5-targeted genes, including 1600 up-regulated genes and 1016 down-regulated genes, were differently expressed in green in comparison to white curd tissue. All these 1600 up-regulated genes were HY5-targeted genes in the light. The genome-wide profiling of gene expression by RNA-seq in green curds led to the identification of large numbers of genes associated with chloroplast development, and suggested the role of regulatory genes in the high hierarchy of light signaling pathways in mediating the ectopic chloroplast development in the green curd cauliflower mutant.

  10. Destruction of pigments and lipids in isolated chloroplasts under the effect of visible radiation

    Merzlyak, M.N.; Pogosyan, S.I.

    1988-01-01

    The results of experiments on the effect of light radiation on lipid and pigment destruction in isolated chloroplasts are generalized. Substrates and products of oxidation destruction of lipid and pigments, the role of photosynthetic electron transport in photodestruction, the participation of activated oxygen and free-radical intermediate forms in it are considered. The role of antioxidants, carotenoids and enzymatic systems in protection of chloroplast membranes from destructive light effect is discussed. A general scheme of possible ways of photodestruction in chloroplasts is presented. 53 refs

  11. Wax deposition in crude oil pipelines

    Assuncao, Pablo Morelato; Rodrigues, Lorennzo Marrochi Nolding [Universidade Federal do Espirito Santo, Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Engenharia de Petroleo; Romero, Mao Ilich [University of Wyoming, Laramie, WY (United States). Enhanced Oil Recovery Institute], e-mail: mromerov@uwyo.edu

    2010-07-01

    Crude oil is a complex mixture of hydrocarbons which consists of aromatics, paraffins, naphthenics, resins asphaltenes, etc. When the temperature of crude oil is reduced, the heavy components, like paraffin, will precipitate and deposit on the pipe internal wall in the form of a wax-oil gel. The gel deposit consists of wax crystals that trap some amount of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. Crude oil may not be able to be re-mobilized during re-startup. The effective diameter will be reduced with wax deposition, resulting in several problems, for example, higher pressure drop which means additional pumping energy costs, poor oil quality, use of chemical components like precipitation inhibitors or flowing facilitators, equipment failure, risk of leakage, clogging of the ducts and process equipment. Wax deposition problems can become so sever that the whole pipeline can be completely blocked. It would cost millions of dollars to remediate an offshore pipeline that is blocked by wax. Wax solubility decreases drastically with decreasing temperature. At low temperatures, as encountered in deep water production, is easy to wax precipitate. The highest temperature below which the paraffins begins to precipitate as wax crystals is defined as wax appearance temperature (WAT). Deposition process is a complex free surface problem involving thermodynamics, fluid dynamics, mass and heat transfer. In this work, a numerical analysis of wax deposition by molecular diffusion and shear dispersion mechanisms in crude oil pipeline is studied. Diffusion flux of wax toward the wall is estimated by Fick's law of diffusion, in similar way the shear dispersion; wax concentration gradient at the solid-liquid interface is obtained by the volume fraction conservation equation; and since the wax deposition

  12. DOE/DOT Crude Oil Characterization Research Study, Task 2 Test Report on Evaluating Crude Oil Sampling and Analysis Methods

    Lord, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allen, Ray [Allen Energy Services, Inc., Longview, TX (United States); Rudeen, David [GRAM, Inc., Albuquerque, NM (United States)

    2017-11-01

    The Crude Oil Characterization Research Study is designed to evaluate whether crude oils currently transported in North America, including those produced from "tight" formations, exhibit physical or chemical properties that are distinct from conventional crudes, and how these properties associate with combustion hazards with may be realized during transportation and handling.

  13. How much crude oil can zooplankton ingest? Estimating the quantity of dispersed crude oil defecated by planktonic copepods

    Almeda, Rodrigo; Connelly, Tara L.; Buskey, Edward J.

    2016-01-01

    % of the analyzed fecal pellets from three species of copepods and a natural copepod assemblage exposed for 48 h to physically or chemically dispersed light crude oil contained crude oil droplets. Crude oil droplets inside fecal pellets were smaller (median diameter: 2.4-3.5 mu m) than droplets in the physically...

  14. The whole chloroplast genome of wild rice (Oryza australiensis).

    Wu, Zhiqiang; Ge, Song

    2016-01-01

    The whole chloroplast genome of wild rice (Oryza australiensis) is characterized in this study. The genome size is 135,224  bp, exhibiting a typical circular structure including a pair of 25,776  bp inverted repeats (IRa,b) separated by a large single-copy region (LSC) of 82,212  bp and a small single-copy region (SSC) of 12,470  bp. The overall GC content of the genome is 38.95%. 110 unique genes were annotated, including 76 protein-coding genes, 4 ribosomal RNA genes, and 30t RNA genes. Among these, 18 are duplicated in the inverted repeat regions, 13 genes contain one intron, and 2 genes (rps12 and ycf3) have two introns.

  15. The complete chloroplast genome sequence of Dianthus superbus var. longicalycinus.

    Gurusamy, Raman; Lee, Do-Hyung; Park, SeonJoo

    2016-05-01

    The complete chloroplast genome (cpDNA) sequence of Dianthus superbus var. longicalycinus is an economically important traditional Chinese medicine was reported and characterized. The cpDNA of Dianthus superbus var. longicalycinus is 149,539 bp, with 36.3% GC content. A pair of inverted repeats (IRs) of 24,803 bp is separated by a large single-copy region (LSC, 82,805 bp) and a small single-copy region (SSC, 17,128 bp). It encodes 85 protein-coding genes, 36 tRNA genes and 8 rRNA genes. Of 129 individual genes, 13 genes encoded one intron and three genes have two introns.

  16. The complete chloroplast genomes of Cannabis sativa and Humulus lupulus.

    Vergara, Daniela; White, Kristin H; Keepers, Kyle G; Kane, Nolan C

    2016-09-01

    Cannabis and Humulus are sister genera comprising the entirety of the Cannabaceae sensu stricto, including C. sativa L. (marijuana, hemp), and H. lupulus L. (hops) as two economically important crops. These two plants have been used by humans for many purposes including as a fiber, food, medicine, or inebriant in the case of C. sativa, and as a flavoring component in beer brewing in the case of H. lupulus. In this study, we report the complete chloroplast genomes for two distinct hemp varieties of C. sativa, Italian "Carmagnola" and Russian "Dagestani", and one Czech variety of H. lupulus "Saazer". Both C. sativa genomes are 153 871 bp in length, while the H. lupulus genome is 153 751 bp. The genomes from the two C. sativa varieties differ in 16 single nucleotide polymorphisms (SNPs), while the H. lupulus genome differs in 1722 SNPs from both C. sativa cultivars.

  17. [Study of Chloroplast DNA Polymorphism in the Sunflower (Helianthus L.)].

    Markina, N V; Usatov, A V; Logacheva, M D; Azarin, K V; Gorbachenko, C F; Kornienko, I V; Gavrilova, V A; Tihobaeva, V E

    2015-08-01

    The polymorphism of microsatellite loci of chloroplast genome in six Helianthus species and 46 lines of cultivated sunflower H. annuus (17 CMS lines and 29 Rf-lines) were studied. The differences between species are confined to four SSR loci. Within cultivated forms of the sunflower H. annuus, the polymorphism is absent. A comparative analysis was performed on sequences of the cpDNA inbred line 3629, line 398941 of the wild sunflower, and the American line HA383 H. annuus. As a result, 52 polymorphic loci represented by 27 SSR and 25 SNP were found; they can be used for genotyping of H. annuus samples, including cultural varieties: twelve polymorphic positions, of which eight are SSR and four are SNP.

  18. Photosynthetic production of diterpenoids in chloroplasts and cyanobacteria

    Vavitsas, Konstantinos

    Terpenoids are one of the largest classes of chemical compounds, some of them with industrial interest as nutraceuticals, biofuels, or chemical feedstocks. Diterpenoids are a large terpenoid subclass, and their chemical structure consists of a core skeleton of 20 carbon atoms. This skeleton can...... be further modified by cyclizing enzymes, and be decorated by the addition of chemical groups. Even though they are mainly plant-derived compounds, diterpenoid production in photosynthetic organisms is rather unexplored, with a few successful studies reported in the literature. In this thesis, I elaborate...... on the potential of using plant chloroplasts and cyanobacteria as biosynthetic vessels, with a focus on diterpenoid production, and on the potential direct linking of photosynthesis to drive electron-consuming enzymes, such as the monooxygenases cytochrome P450s. I subsequently present the full localization...

  19. Functional analysis of chloroplast early light inducible proteins (ELIPs)

    Wetzel, Carolyn M

    2005-02-22

    The objectives of this project were to characterize gene expression patterns of early light inducible protein (ELIP) genes in Arabidopsis thaliana and in Lycopersicon esculentum, to identify knock mutants of the 2 ELIP genes in Arabidopsis, and to characterize the effects of the knockouts. Expression in Arabidopsis was studied in response to thylakoid electron transport chain (PETC) capacity, where it was found that there is a signal for expression associated with reduction of the PETC. Expression in response to salt was also studied, with different responses of the two gene copies. Knockout lines for ELIP1 and ELIP2 have been identified and are being characterized. In tomato, it was found that the single-copy ELIP gene is highly expressed in ripening fruit during the chloroplast-to-chromoplast transition. Studies of expression in tomato ripening mutants are ongoing.

  20. The complete chloroplast genome of Sinopodophyllum hexandrum Ying (Berberidaceae).

    Meng, Lihua; Liu, Ruijuan; Chen, Jianbing; Ding, Chenxu

    2017-05-01

    The complete nucleotide sequence of the Sinopodophyllum hexandrum Ying chloroplast genome (cpDNA) was determined based on next-generation sequencing technologies in this study. The genome was 157 203 bp in length, containing a pair of inverted repeat (IRa and IRb) regions of 25 960 bp, which were separated by a large single-copy (LSC) region of 87 065 bp and a small single-copy (SSC) region of 18 218 bp, respectively. The cpDNA contained 148 genes, including 96 protein-coding genes, 8 ribosomal RNA genes, and 44 tRNA genes. In these genes, eight harbored a single intron, and two (ycf3 and clpP) contained a couple of introns. The cpDNA AT content of S. hexandrum cpDNA is 61.5%.

  1. The complete chloroplast genome of Sinopodophyllum hexandrum (Berberidaceae).

    Li, Huie; Guo, Qiqiang

    2016-07-01

    The complete chloroplast (cp) genome of the Sinopodophyllum hexandrum (Berberidaceae) was determined in this study. The circular genome is 157,940 bp in size, and comprises a pair of inverted repeat (IR) regions of 26,077 bp each, a large single-copy (LSC) region of 86,460 bp and a small single-copy (SSC) region of 19,326 bp. The GC content of the whole cp genome was 38.5%. A total of 133 genes were identified, including 88 protein-coding genes, 37 tRNA genes and eight rRNA genes. The whole cp genome consists of 114 unique genes, and 19 genes are duplicated in the IR regions. The phylogenetic analysis revealed that S. hexandrum is closely related to Nandina domestica within the family Berberidaceae.

  2. The complete chloroplast genome sequence of Euonymus japonicus (Celastraceae).

    Choi, Kyoung Su; Park, SeonJoo

    2016-09-01

    The complete chloroplast (cp) genome sequence of the Euonymus japonicus, the first sequenced of the genus Euonymus, was reported in this study. The total length was 157 637 bp, containing a pair of 26 678 bp inverted repeat region (IR), which were separated by small single copy (SSC) region and large single copy (LSC) region of 18 340 bp and 85 941 bp, respectively. This genome contains 107 unique genes, including 74 coding genes, four rRNA genes, and 29 tRNA genes. Seventeen genes contain intron of E. japonicus, of which three genes (clpP, ycf3, and rps12) include two introns. The maximum likelihood (ML) phylogenetic analysis revealed that E. japonicus was closely related to Manihot and Populus.

  3. The complete chloroplast genome sequence of Dendrobium nobile.

    Yan, Wenjin; Niu, Zhitao; Zhu, Shuying; Ye, Meirong; Ding, Xiaoyu

    2016-11-01

    The complete chloroplast (cp) genome sequence of Dendrobium nobile, an endangered and traditional Chinese medicine with important economic value, is presented in this article. The total genome size is 150,793 bp, containing a large single copy (LSC) region (84,939 bp) and a small single copy region (SSC) (13,310 bp) which were separated by two inverted repeat (IRs) regions (26,272 bp). The overall GC contents of the plastid genome were 38.8%. In total, 130 unique genes were annotated and they were consisted of 76 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Fourteen genes contained one or two introns.

  4. Intracellular compartimentation of abscisic acid (ABA) in guard cells and mesophyll cells under exposure to SO sub 2. Kompartimentierung von Abscisinsaeure (ABA) in Schliess- und Mesophyllzellen unter SO sub 2 -Belastung

    Baier, M.; Daeter, W.; Hartung, W. (Wuerzburg Univ. (Germany, F.R.). Lehrstuhl fuer Botanik 1)

    1989-07-01

    The effect of SO{sub 2} on the intracellular compartimentation of ABA in guard cells and mesophyll cells of Valerianella locusta was investigated, using the efflux compartmental analysis, as described by Behl and Hartung (1986). The cytoplasmic ABA content of the guard cells was reduced drastically by 6 {mu}molxm{sup -3} SO{sub 2} (20% of the controls). The vacuolar content was decreased less dramatically (70% of the controls). The ABA distribution of mesophyll cells remained uneffected by 6 {mu}molxm{sup -3} SO{sub 2}. The SO{sub 2} effects are explained by an acidification of the compartments. (orig.).

  5. Influence of pH on the /sup 14/C-labelling pattern after photosynthesis of suspended leaf slices and isolated mesophyll cells from chenopodium album in NaH/sup 14/CO/sub 3/

    Baumann, G; Guenther, G [Paedagogische Hochschule Karl Liebknecht, Potsdam (German Democratic Republic). Sektion Chemie/Biologie

    1983-01-01

    Photosynthetic fixation of /sup 14/C from solutions of NaH/sup 14/CO/sub 3/ (at constant concentrations of free CO/sub 2/) by suspended leaf slices or isolated mesophyll cells from Chenopodium album is increased with increasing pH. Above all, the incorporation of radioactivity into amino acids and malate is stimulated. A direct uptake of HCO/sub 3/ ions and its fixation by PEP carboxylase is suggested. Isolated mesophyll cells showed at pH 7.3 a higher rate of photosynthesis than at pH 5.0.

  6. Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.

    Ruiz, Oscar N; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

    2011-06-01

    Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183,000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioneins in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  7. Implications of globalization on pricing for Canadian crudes

    Black, R. [Canadian Occidental Petroleum Ltd., Calgary, AB (Canada)

    1998-05-01

    The effects of globalization on Canadian crude oil prices was discussed. Since deregulation in October 1985, Canadian crude oil has competed directly against international crude oil through the use of the NYMEX contract price for light sweet crude oil as the base for establishing the price for Canadian crudes. Prior to that date, Alberta crude was marketed by the Alberta Petroleum Marketing Commission using the old block matrix which was loosely tied to the world market price. In addition to world crude oil prices other factors that affect the price of Canadian crude oil include technology impacts and global integration. Also, when the Sarnia to Montreal pipeline (Line 9) is reversed to bring offshore crude oil into the Ontario refining community, Canadian producers can expect some adverse effects on the price they are paid for their products leading up to the reversal as refiners start to swing over to their alternate suppliers. The offshore supply is expected to be about 140,000 barrels/day of light sweet crude oil, but all grades of Canadian crude oil will be affected.

  8. Water deficit affects mesophyll limitation of leaves more strongly in sun than in shade in two contrasting Picea asperata populations.

    Duan, Baoli; Li, Yan; Zhang, Xiaolu; Korpelainen, Helena; Li, Chunyang

    2009-12-01

    The aim of this study was to examine the response of internal conductance to CO(2) (g(i)) to soil water deficit and contrasting light conditions, and their consequences on photosynthetic physiology in two Picea asperata Mast. populations originating from wet and dry climate regions of China. Four-year-old trees were subjected to two light treatments (30% and 100% of full sunlight) and two watering regimes (well watered, drought) for 2 years. In both tested populations, drought significantly decreased g(i) and the net photosynthesis rate (A) and increased carbon isotope composition (delta(13)C) values in both light treatments, in particular in the sun. Moreover, drought resulted in a significantly higher relative limitation due to stomatal conductance (L(s)) in both light treatments and higher relative limitation due to internal conductance (L(i)) and abscisic acid (ABA) in the sun plants. The results also showed that L(i) (0.26-0.47) was always greater than L(s) (0.12-0.28). On the other hand, drought significantly decreased the ratio of chloroplastic to internal CO(2) concentration (C(c)/C(i)), photosynthetic nitrogen utilization efficiency (PNUE) and total biomass in the sun plants of the wet climate population, whereas there were no significant changes in these parameters in the dry climate population. Our results also showed that the dry climate population possessed higher delta(13)C values with higher ratio of internal conductance to stomatal conductance (g(i)/g(s)), suggesting that increasing the g(i)/g(s) ratio enhances water-use efficiency (WUE) in plants evolved in arid environments. Thus, we propose that the use of the g(i)/g(s) parameter to screen P. asperata plants with higher water deficit tolerance is certainly worthy of consideration. Furthermore, g(i) is an important variable, which reflects the population differences in PNUE, and it should thus be included in plant physiological investigations related to leaf economics.

  9. Dispersed catalysts for transforming extra heavy crude oil into transportable upgraded crude: phase identification

    Martinez, S.; Canizales, E.; Machin, I. [Gerencia Depttal de Investigacion Estrategica en Refinacion PDVSA Intevep (Venezuela); Segovia, X.; Rivas, A.; Lopez, E.; Pena, J.P.; Rojas, J.D.; Sardella, R. [Gerencia Depttal de Infraestructura y Mejoramiento en Faja Petrolifera PDVSA Intevep (Venezuela)

    2011-07-01

    A new technology to convert extra heavy crude oil into transportable upgraded crude has been developed. A water/oil emulsion composed of steam and catalyst precursors is introduced in the feed which then generates unsupported dispersed catalyst in situ under thermal decomposition. The aim of this paper is to characterize the particles. The study was conducted in a laboratory and on a pilot scale on three different vacuum residues using high resolution transmission electron microscopy and a transmission electron microscope. Results showed that the particles were formed by oxides and inorganic sulphur based in transition metals and their sizes ranged between 5 and 120 nm; in addition, good dispersion was observed. This study demonstrated that the process involved in the generation of dispersed catalyst is extremely complex and showed that further work with heavy crude oils and its residua is required to understand the mechanisms involved.

  10. The complete chloroplast genomes of two Wisteria species, W. floribunda and W. sinensis (Fabaceae).

    Kim, Na-Rae; Kim, Kyunghee; Lee, Sang-Choon; Lee, Jung-Hoon; Cho, Seong-Hyun; Yu, Yeisoo; Kim, Young-Dong; Yang, Tae-Jin

    2016-11-01

    Wisteria floribunda and Wisteria sinensis are ornamental woody vines in the Fabaceae. The complete chloroplast genome sequences of the two species were generated by de novo assembly using whole genome next generation sequences. The chloroplast genomes of W. floribunda and W. sinensis were 130 960 bp and 130 561 bp long, respectively, and showed inverted repeat (IR)-lacking structures as those reported in IRLC in the Fabaceae. The chloroplast genomes of both species contained same number of protein-coding sequences (77), tRNA genes (30), and rRNA genes (4). The phylogenetic analysis with the reported chloroplast genomes confirmed close taxonomical relationship of W. floribunda and W. sinensis.

  11. Formation and scavenging of superoxide in chloroplasts, with relation to injury by sulfur dioxide

    Asada, K

    1980-01-01

    Injury of plant leaf cells by sulfur dioxide-exposure is greater in day time than in night. A hypothesis is proposed that the free radical chain oxidation of sulfite is initiated by the superoxide radicals (O/sub 2//sup -/) produced in illuminated chloroplasts, and that the resulting amplified production of O/sub 2//sup -/, the hydroxyl radicals and the bisulfite radicals causes the injury of leaf tissues. In this review, the production of O/sub 2//sup -/ in illuminated chloroplasts and scavenging of O/sub 2//sup -/ by superoxide dismutase and their relation to oxidation of sulfite in chloroplasts are discussed. Superoxide dismutase in chloroplasts plays an important role in protecting leaf cells from injury by sulfur dioxide.

  12. Comparative analyses of chloroplast genome data representing nine green algae in Sphaeropleales (Chlorophyceae, Chlorophyta

    Karolina Fučíková

    2016-06-01

    Full Text Available The chloroplast genomes of green algae are highly variable in their architecture. In this article we summarize gene content across newly obtained and published chloroplast genomes in Chlorophyceae, including new data from nine of species in Sphaeropleales (Chlorophyceae, Chlorophyta. We present genome architecture information, including genome synteny analysis across two groups of species. Also, we provide a phylogenetic tree obtained from analysis of gene order data for species in Chlorophyceae with fully sequenced chloroplast genomes. Further analyses and interpretation of the data can be found in “Chloroplast phylogenomic data from the green algal order Sphaeropleales (Chlorophyceae, Chlorophyta reveal complex patterns of sequence evolution” (Fučíková et al., In review [1].

  13. Chloroplasts activity and PAP-signaling regulate programmed cell death in Arabidopsis

    Bruggeman, Quentin; Mazubert, Christelle; Prunier, Florence; Lugan, Raphael; Chan, Kai Xun; Phua, Su Yin; Pogson, Barry J.; Krieger-Liszkay, Anja; Delarue, Marianne; Benhamed, Moussa; Bergounioux, Catherine; Raynaud, Cé cile

    2016-01-01

    Programmed cell death (PCD) is a crucial process both for plant development and responses to biotic and abiotic stress. There is accumulating evidence that chloroplasts may play a central role during plant PCD as for mitochondria in animal cells

  14. The metabolism of sorbitol and fructose in isolated chloroplasts of Santa Rosa plum leaves

    De Villiers, O.T.

    1979-01-01

    Aqueously as well as non-aqueously isolated chloroplasts from Santa Rosa plum leaves readily metabolised sorbitol- 14 C to fructose, glucose and sucrose. Likewise, fructose- 14 C was converted to sorbitol, glucose and sucrose [af

  15. Genetic polymorphism in Gymnodinium galatheanum chloroplast DNA sequences and development of a molecular detection assay.

    Tengs, T; Bowers, H A; Ziman, A P; Stoecker, D K; Oldach, D W

    2001-02-01

    Nuclear and chloroplast-encoded small subunit ribosomal DNA sequences were obtained from several strains of the toxic dinoflagellate Gymnodinium galatheanum. Phylogenetic analyses and comparison of sequences indicate that the chloroplast sequences show a higher degree of sequence divergence than the nuclear homologue. The chloroplast sequences were chosen as targets for the development of a 5'--3' exonuclease assay for detection of the organism. The assay has a very high degree of specificity and has been used to screen environmental water samples from a fish farm where the presence of this dinoflagellate species has previously been associated with fish kills. Various hypotheses for the derived nature of the chloroplast sequences are discussed, as well as what is known about the toxicity of the species.

  16. Confocal laser scanning microscopy detection of chlorophylls and carotenoids in chloroplasts and chromoplasts of tomato fruit.

    D'Andrea, Lucio; Amenós, Montse; Rodríguez-Concepción, Manuel

    2014-01-01

    Plant cells are unique among eukaryotic cells because of the presence of plastids, including chloroplasts and chromoplasts. Chloroplasts are found in green tissues and harbor the photosynthetic machinery (including chlorophyll molecules), while chromoplasts are present in non-photosynthetic tissues and accumulate large amounts of carotenoids. During tomato fruit development, chloroplasts are converted into chromoplasts that accumulate high levels of lycopene, a linear carotenoid responsible for the characteristic red color of ripe fruit. Here, we describe a simple and fast method to detect both types of fully differentiated plastids (chloroplasts and chromoplasts), as well as intermediate stages, in fresh tomato fruits. The method is based on the differential autofluorescence of chlorophylls and carotenoids (lycopene) detected by Confocal Laser Scanning Microscopy.

  17. Regulation of chloroplast number and DNA synthesis in higher plants. Final report

    Mullet, J.E.

    1995-11-10

    The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focuses on obtaining a detailed description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The grant will also begin analysis of specific biochemical mechanisms by isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell.

  18. Frataxin Is Localized to Both the Chloroplast and Mitochondrion and Is Involved in Chloroplast Fe-S Protein Function in Arabidopsis.

    Valeria R Turowski

    Full Text Available Frataxin plays a key role in eukaryotic cellular iron metabolism, particularly in mitochondrial heme and iron-sulfur (Fe-S cluster biosynthesis. However, its precise role has yet to be elucidated. In this work, we studied the subcellular localization of Arabidopsis frataxin, AtFH, using confocal microscopy, and found a novel dual localization for this protein. We demonstrate that plant frataxin is targeted to both the mitochondria and the chloroplast, where it may play a role in Fe-S cluster metabolism as suggested by functional studies on nitrite reductase (NIR and ferredoxin (Fd, two Fe-S containing chloroplast proteins, in AtFH deficient plants. Our results indicate that frataxin deficiency alters the normal functioning of chloroplasts by affecting the levels of Fe, chlorophyll, and the photosynthetic electron transport chain in this organelle.

  19. Enzymic synthesis of γ-coniceine in Conium maculatum chloroplasts and mitochondria.

    Roberts, M F

    1981-08-01

    Further studies of the transaminase responsible for the first committed step in alkaloid formation in Conium maculatum have shown the L-alanine: 5-ketooctanal transaminase to occur in both the mitochondria and chloroplast. Experiments suggest that these enzymes are the isoenzymes Transaminase A and B respectively previously isolated by the author. It is suggested that the chloroplast enzyme is normally responsible for alkaloid production.

  20. Release of proteins from intact chloroplasts induced by reactive oxygen species during biotic and abiotic stress.

    Kwon, Kwang-Chul; Verma, Dheeraj; Jin, Shuangxia; Singh, Nameirakpam D; Daniell, Henry

    2013-01-01

    Plastids sustain life on this planet by providing food, feed, essential biomolecules and oxygen. Such diverse metabolic and biosynthetic functions require efficient communication between plastids and the nucleus. However, specific factors, especially large molecules, released from plastids that regulate nuclear genes have not yet been fully elucidated. When tobacco and lettuce transplastomic plants expressing GFP within chloroplasts, were challenged with Erwinia carotovora (biotic stress) or paraquat (abiotic stress), GFP was released into the cytoplasm. During this process GFP moves gradually towards the envelope, creating a central red zone of chlorophyll fluorescence. GFP was then gradually released from intact chloroplasts into the cytoplasm with an intact vacuole and no other visible cellular damage. Different stages of GFP release were observed inside the same cell with a few chloroplasts completely releasing GFP with detection of only red chlorophyll fluorescence or with no reduction in GFP fluorescence or transitional steps between these two phases. Time lapse imaging by confocal microscopy clearly identified sequence of these events. Intactness of chloroplasts during this process was evident from chlorophyll fluorescence emanated from thylakoid membranes and in vivo Chla fluorescence measurements (maximum quantum yield of photosystem II) made before or after infection with pathogens to evaluate their photosynthetic competence. Hydrogen peroxide and superoxide anion serve as signal molecules for generation of reactive oxygen species and Tiron, scavenger of superoxide anion, blocked release of GFP from chloroplasts. Significant increase in ion leakage in the presence of paraquat and light suggests changes in the chloroplast envelope to facilitate protein release. Release of GFP-RC101 (an antimicrobial peptide), which was triggered by Erwinia infection, ceased after conferring protection, further confirming this export phenomenon. These results suggest a

  1. Release of proteins from intact chloroplasts induced by reactive oxygen species during biotic and abiotic stress.

    Kwang-Chul Kwon

    Full Text Available Plastids sustain life on this planet by providing food, feed, essential biomolecules and oxygen. Such diverse metabolic and biosynthetic functions require efficient communication between plastids and the nucleus. However, specific factors, especially large molecules, released from plastids that regulate nuclear genes have not yet been fully elucidated. When tobacco and lettuce transplastomic plants expressing GFP within chloroplasts, were challenged with Erwinia carotovora (biotic stress or paraquat (abiotic stress, GFP was released into the cytoplasm. During this process GFP moves gradually towards the envelope, creating a central red zone of chlorophyll fluorescence. GFP was then gradually released from intact chloroplasts into the cytoplasm with an intact vacuole and no other visible cellular damage. Different stages of GFP release were observed inside the same cell with a few chloroplasts completely releasing GFP with detection of only red chlorophyll fluorescence or with no reduction in GFP fluorescence or transitional steps between these two phases. Time lapse imaging by confocal microscopy clearly identified sequence of these events. Intactness of chloroplasts during this process was evident from chlorophyll fluorescence emanated from thylakoid membranes and in vivo Chla fluorescence measurements (maximum quantum yield of photosystem II made before or after infection with pathogens to evaluate their photosynthetic competence. Hydrogen peroxide and superoxide anion serve as signal molecules for generation of reactive oxygen species and Tiron, scavenger of superoxide anion, blocked release of GFP from chloroplasts. Significant increase in ion leakage in the presence of paraquat and light suggests changes in the chloroplast envelope to facilitate protein release. Release of GFP-RC101 (an antimicrobial peptide, which was triggered by Erwinia infection, ceased after conferring protection, further confirming this export phenomenon. These

  2. Chloroplast and mitochondrial microsatellites for Millettia pinnata (Fabaceae) and cross-amplification in related species 1

    Wang, Yanling; Xie, Hongxian; Yang, Yi; Huang, Yelin; Wang, Jianwu; Tan, Fengxiao

    2017-01-01

    Premise of the study: Chloroplast and mitochondrial microsatellites were identified to study the population genetics of Millettia pinnata (Fabaceae). Methods and Results: Based on publicly available plastid genome sequence data of M. pinnata, 42 primer pairs were developed, of which 17 displayed polymorphisms across 89 individuals from four populations. For chloroplast loci, two to six alleles were recovered and the unbiased haploid diversity per locus ranged from 0.391 to 0.857. For mitochon...

  3. Transcriptional regulation and DNA methylation in plastids during transitional conversion of chloroplasts to chromoplasts.

    Kobayashi, H; Ngernprasirtsiri, J; Akazawa, T

    1990-01-01

    During transitional conversion of chloroplasts to chromoplasts in ripening tomato (Lycopersicon esculentum) fruits, transcripts for several plastid genes for photosynthesis decreased to undetectable levels. Run-on transcription of plastids indicated that transcriptional regulation operated as a predominant factor. We found that most of the genes in chloroplasts were actively transcribed in vitro by Escherichia coli and soluble plastid RNA polymerases, but some genes in chromoplasts seemed to ...

  4. Effect of Radiation Dosage on Efficiency of Chloroplast Transfer by Protoplast Fusion in Nicotiana

    Menczel, László; Galiba, Gábor; Nagy, Ferenc; Maliga, Pál

    1982-01-01

    Chloroplasts of Nicotiana tabacum SR1 were transferred into Nicotiana plumbaginifolia by protoplast fusion. The protoplasts of the organelle donor were irradiated with different lethal doses using a 60Co source, to facilitate the elimination of their nuclei from the fusion products. After fusion induction, clones derived from fusion products and containing streptomycin-resistant N. tabacum SR1 chloroplasts were selected by their ability to green on a selective medium. When N. tabacum protopla...

  5. Transient leak detection in crude oil pipelines

    Beushausen, R.; Tornow, S.; Borchers, H. [Nord-West Oelleitung, Wilhelmshaven (Germany); Murphy, K.; Zhang, J. [Atmos International Ltd., Manchester (United Kingdom)

    2004-07-01

    Nord-West Oelleitung (NWO) operates 2 crude oil pipelines from Wilhemshaven to Koln and Hamburg respectively. German regulations for transporting flammable substances stipulate that 2 independent continuously working procedures be used to detect leaks. Leak detection pigs are used routinely to complement the surveillance system. This paper described the specific issues of transient leak detection in crude oil pipelines. It was noted that traditional methods have failed to detect leaks that occur immediately after pumps are turned on or off because the pressure wave generated by the transient dominates the pressure wave that results from the leak. Frequent operational changes in a pipeline are often accompanied by an increased number of false alarms and failure to detect leaks due to unsteady operations. NWO therefore decided to have the Atmos statistical pipeline leak detection (SPLD) system installed on their pipelines. The key to the SPLD system is the sequential probability ratio test. Comprehensive data validation is performed following reception of pipeline data from the supervisory control and data acquisition (SCADA) system. The validated data is then used to calculate the corrected flow imbalance, which is fed into the SPRT to determine if there is an increase in the flow imbalance. Pattern recognition is then used to distinguish a leak from operational changes. The SPLD is unique because it uses 3 computational pipeline monitoring methods simultaneously, namely modified volume balance, statistical analysis, and pressure and flow monitoring. The successful installation and testing of the SPLD in 2 crude oil pipelines was described along with the main difficulties associated with transient leaks. Field results were presented for both steady-state and transient conditions. 5 refs., 2 tabs., 16 figs.

  6. Characterization of the snowy cotyledon 1 mutant of Arabidopsis thaliana: the impact of chloroplast elongation factor G on chloroplast development and plant vitality.

    Albrecht, Verónica; Ingenfeld, Anke; Apel, Klaus

    2006-03-01

    During seedling development chloroplast formation marks the transition from heterotrophic to autotrophic growth. The development and activity of chloroplasts may differ in cotyledons that initially serve as a storage organ and true leaves whose primary function is photosynthesis. A genetic screen was used for the identification of genes that affect selectively chloroplast function in cotyledons of Arabidopsis thaliana. Several mutants exhibiting pale cotyledons and green true leaves were isolated and dubbed snowy cotyledon (sco). One of the mutants, sco1, was characterized in more detail. The mutated gene was identified using map-based cloning. The mutant contains a point mutation in a gene encoding the chloroplast elongation factor G, leading to an amino acid exchange within the predicted 70S ribosome-binding domain. The mutation results in a delay in the onset of germination. At this early developmental stage embryos still contain undifferentiated proplastids, whose proper function seems necessary for seed germination. In light-grown sco1 seedlings the greening of cotyledons is severely impaired, whereas the following true leaves develop normally as in wild-type plants. Despite this apparent similarity of chloroplast development in true leaves of mutant and wild-type plants various aspects of mature plant development are also affected by the sco1 mutation such as the onset of flowering, the growth rate, and seed production. The onset of senescence in the mutant and the wild-type plants occurs, however, at the same time, suggesting that in the mutant this particular developmental step does not seem to suffer from reduced protein translation efficiency in chloroplasts.

  7. Chloroplast overexpression of rice caffeic acid O-methyltransferase increases melatonin production in chloroplasts via the 5-methoxytryptamine pathway in transgenic rice plants.

    Choi, Geun-Hee; Lee, Hyoung Yool; Back, Kyoungwhan

    2017-08-01

    Recent analyses of the enzymatic features of various melatonin biosynthetic genes from bacteria, animals, and plants have led to the hypothesis that melatonin could be synthesized via the 5-methoxytryptamine (5-MT) pathway. 5-MT is known to be synthesized in vitro from serotonin by the enzymatic action of O-methyltransferases, including N-acetylserotonin methyltransferase (ASMT) and caffeic acid O-methyltransferase (COMT), leading to melatonin synthesis by the subsequent enzymatic reaction with serotonin N-acetyltransferase (SNAT). Here, we show that 5-MT was produced and served as a precursor for melatonin synthesis in plants. When rice seedlings were challenged with senescence treatment, 5-MT levels and melatonin production were increased in transgenic rice seedlings overexpressing the rice COMT in chloroplasts, while no such increases were observed in wild-type or transgenic seedlings overexpressing the rice COMT in the cytosol, suggesting a 5-MT transport limitation from the cytosol to chloroplasts. In contrast, cadmium treatment led to results different from those in senescence. The enhanced melatonin production was not observed in the chloroplast COMT lines relative over the cytosol COMT lines although 5-MT levels were equally induced in all genotypes upon cadmium treatment. The transgenic seedlings with enhanced melatonin in their chloroplasts exhibited improved seedling growth vs the wild type under continuous light conditions. This is the first report describing enhanced melatonin production in chloroplasts via the 5-MT pathway with the ectopic overexpression of COMT in chloroplasts in plants. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. A crude scaling law for lasertrons

    Rees, J.

    1987-11-01

    The lasertron is under consideration in several laboratories as a promising new source of high-power microwaves that is competitive with conventional klystrons in its properties - particularly in efficiency. In this note, a crude scaling law for high-power lasertrons is derived based on the observation that the main limiting phenomenon, the phenomenon that curtails the tube's efficiency, is debunching due to longitudinal space-charge forces acting in the electron gun. The scaling law indicates that lasertrons are quite restricted in the power they can generate at high frequencies

  9. Vulnerability maps for Druzba crude oil pipeline

    Hladik, P.; Hosnedl, P.; Buresova, H.; Corbet, J.

    2012-01-01

    Maps of risk for individual environmental aspects within the protection zone of the Czech part of the Druzba crude oil pipeline (505.7 km) were developed based on a modified 'H and V index' method. Risk data were added into a GIS of the Druzba pipeline so that the system could be used as conceptual material in the field of environmental protection (a base for the new SCADA system). Considered environmental aspects were assessed in terms of their vulnerability. The criteria were defined as the vulnerability of the aquatic environment (surface waters and ground waters), the vulnerability of soil environment and the vulnerability of biotic components of the environment. (authors)

  10. Conflict amongst chloroplast DNA sequences obscures the phylogeny of a group of Asplenium ferns.

    Shepherd, Lara D; Holland, Barbara R; Perrie, Leon R

    2008-07-01

    A previous study of the relationships amongst three subgroups of the Austral Asplenium ferns found conflicting signal between the two chloroplast loci investigated. Because organelle genomes like those of chloroplasts and mitochondria are thought to be non-recombining, with a single evolutionary history, we sequenced four additional chloroplast loci with the expectation that this would resolve these relationships. Instead, the conflict was only magnified. Although tree-building analyses favoured one of the three possible trees, one of the alternative trees actually had one more supporting site (six versus five) and received greater support in spectral and neighbor-net analyses. Simulations suggested that chance alone was unlikely to produce strong support for two of the possible trees and none for the third. Likelihood permutation tests indicated that the concatenated chloroplast sequence data appeared to have experienced recombination. However, recombination between the chloroplast genomes of different species would be highly atypical, and corollary supporting observations, like chloroplast heteroplasmy, are lacking. Wider taxon sampling clarified the composition of the Austral group, but the conflicting signal meant analyses (e.g., morphological evolution, biogeographic) conditional on a well-supported phylogeny could not be performed.

  11. Comparative analysis of complete chloroplast genome sequence and inversion variation in Lasthenia burkei (Madieae, Asteraceae).

    Walker, Joseph F; Zanis, Michael J; Emery, Nancy C

    2014-04-01

    Complete chloroplast genome studies can help resolve relationships among large, complex plant lineages such as Asteraceae. We present the first whole plastome from the Madieae tribe and compare its sequence variation to other chloroplast genomes in Asteraceae. We used high throughput sequencing to obtain the Lasthenia burkei chloroplast genome. We compared sequence structure and rates of molecular evolution in the small single copy (SSC), large single copy (LSC), and inverted repeat (IR) regions to those for eight Asteraceae accessions and one Solanaceae accession. The chloroplast sequence of L. burkei is 150 746 bp and contains 81 unique protein coding genes and 4 coding ribosomal RNA sequences. We identified three major inversions in the L. burkei chloroplast, all of which have been found in other Asteraceae lineages, and a previously unreported inversion in Lactuca sativa. Regions flanking inversions contained tRNA sequences, but did not have particularly high G + C content. Substitution rates varied among the SSC, LSC, and IR regions, and rates of evolution within each region varied among species. Some observed differences in rates of molecular evolution may be explained by the relative proportion of coding to noncoding sequence within regions. Rates of molecular evolution vary substantially within and among chloroplast genomes, and major inversion events may be promoted by the presence of tRNAs. Collectively, these results provide insight into different mechanisms that may promote intramolecular recombination and the inversion of large genomic regions in the plastome.

  12. Short-term effects of salt exposure on the maize chloroplast protein pattern.

    Zörb, Christian; Herbst, Ramona; Forreiter, Christoph; Schubert, Sven

    2009-09-01

    It is of fundamental importance to understand the physiological differences leading to salt resistance and to get access to the molecular mechanisms underlying this physiological response. The aim of this work was to investigate the effects of short-term salt exposure on the proteome of maize chloroplasts in the initial phase of salt stress (up to 4 h). It could be shown that sodium ions accumulate quickly and excessively in chloroplasts in the initial phase of moderate salt stress. A change in the chloroplast protein pattern was observed without a change in water potential of the leaves. 2-DE revealed that 12 salt-responsive chloroplast proteins increased while eight chloroplast proteins decreased. Some of the maize chloroplast proteins such as CF1e and a Ca(2+)-sensing receptor show a rather transient response for the first 4 h of salt exposure. The enhanced abundance of the ferredoxin NADPH reductase, the 23 kDa polypeptide of the photosystem II, and the FtsH-like protein might reflect mechanism to attenuate the detrimental effects of Na(+) on the photosynthetic machinery. The observed transient increase and subsequent decrease of selected proteins may exhibit a counterbalancing effect of target proteins in this context. Intriguingly, several subunits of the CF1-CF0 complex are unequally affected, whereas others do not respond at all.

  13. A database of PCR primers for the chloroplast genomes of higher plants

    Heinze, Berthold

    2007-01-01

    Background Chloroplast genomes evolve slowly and many primers for PCR amplification and analysis of chloroplast sequences can be used across a wide array of genera. In some cases 'universal' primers have been designed for the purpose of working across species boundaries. However, the essential information on these primer sequences is scattered throughout the literature. Results A database is presented here which assembles published primer information for chloroplast DNA. Additional primers were designed to fill gaps where little or no primer information could be found. Amplicons are either the genes themselves (typically useful in studies of sequence variation in higher-order phylogeny) or they are spacers, introns, and intergenic regions (for studies of phylogeographic patterns within and among species). The current list of 'generic' primers consists of more than 700 sequences. Wherever possible, we give the locations of the primers in the thirteen fully sequenced chloroplast genomes (Nicotiana tabacum, Atropa belladonna, Spinacia oleracea, Arabidopsis thaliana, Populus trichocarpa, Oryza sativa, Pinus thunbergii, Marchantia polymorpha, Zea mays, Oenothera elata, Acorus calamus, Eucalyptus globulus, Medicago trunculata). Conclusion The database described here is designed to serve as a resource for researchers who are venturing into the study of poorly described chloroplast genomes, whether for large- or small-scale DNA sequencing projects, to study molecular variation or to investigate chloroplast evolution. PMID:17326828

  14. A database of PCR primers for the chloroplast genomes of higher plants

    Heinze Berthold

    2007-02-01

    Full Text Available Abstract Background Chloroplast genomes evolve slowly and many primers for PCR amplification and analysis of chloroplast sequences can be used across a wide array of genera. In some cases 'universal' primers have been designed for the purpose of working across species boundaries. However, the essential information on these primer sequences is scattered throughout the literature. Results A database is presented here which assembles published primer information for chloroplast DNA. Additional primers were designed to fill gaps where little or no primer information could be found. Amplicons are either the genes themselves (typically useful in studies of sequence variation in higher-order phylogeny or they are spacers, introns, and intergenic regions (for studies of phylogeographic patterns within and among species. The current list of 'generic' primers consists of more than 700 sequences. Wherever possible, we give the locations of the primers in the thirteen fully sequenced chloroplast genomes (Nicotiana tabacum, Atropa belladonna, Spinacia oleracea, Arabidopsis thaliana, Populus trichocarpa, Oryza sativa, Pinus thunbergii, Marchantia polymorpha, Zea mays, Oenothera elata, Acorus calamus, Eucalyptus globulus, Medicago trunculata. Conclusion The database described here is designed to serve as a resource for researchers who are venturing into the study of poorly described chloroplast genomes, whether for large- or small-scale DNA sequencing projects, to study molecular variation or to investigate chloroplast evolution.

  15. Chloroplasts activity and PAP-signaling regulate programmed cell death in Arabidopsis

    Bruggeman, Quentin

    2016-01-09

    Programmed cell death (PCD) is a crucial process both for plant development and responses to biotic and abiotic stress. There is accumulating evidence that chloroplasts may play a central role during plant PCD as for mitochondria in animal cells, but it is still unclear whether they participate in PCD onset, execution, or both. To tackle this question, we have analyzed the contribution of chloroplast function to the cell death phenotype of the myoinositol phosphate synthase1 (mips1) mutant that forms spontaneous lesions in a light-dependent manner. We show that photosynthetically active chloroplasts are required for PCD to occur in mips1, but this process is independent of the redox state of the chloroplast. Systematic genetic analyses with retrograde signaling mutants reveal that 3’-phosphoadenosine 5’-phosphate, a chloroplast retrograde signal that modulates nuclear gene expression in response to stress, can inhibit cell death and compromises plant innate immunity via inhibition of the RNA-processing 5’-3’ exoribonucleases. Our results provide evidence for the role of chloroplast-derived signal and RNA metabolism in the control of cell death and biotic stress response. © 2016 American Society of Plant Biologists. All Rights Reserved.

  16. Arabidopsis VARIEGATED 3 encodes a chloroplast-targeted, zinc-finger protein required for chloroplast and palisade cell development

    Næsted, Henrik; Holm, Agnethe; Jenkins, Tom

    2004-01-01

    The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3...... that pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development....

  17. Protoplast isolation, transient transformation of leaf mesophyll protoplasts and improved Agrobacterium-mediated leaf disc infiltration of Phaseolus vulgaris: tools for rapid gene expression analysis.

    Nanjareddy, Kalpana; Arthikala, Manoj-Kumar; Blanco, Lourdes; Arellano, Elizabeth S; Lara, Miguel

    2016-06-24

    Phaseolus vulgaris is one of the most extensively studied model legumes in the world. The P. vulgaris genome sequence is available; therefore, the need for an efficient and rapid transformation system is more imperative than ever. The functional characterization of P. vulgaris genes is impeded chiefly due to the non-amenable nature of Phaseolus sp. to stable genetic transformation. Transient transformation systems are convenient and versatile alternatives for rapid gene functional characterization studies. Hence, the present work focuses on standardizing methodologies for protoplast isolation from multiple tissues and transient transformation protocols for rapid gene expression analysis in the recalcitrant grain legume P. vulgaris. Herein, we provide methodologies for the high-throughput isolation of leaf mesophyll-, flower petal-, hypocotyl-, root- and nodule-derived protoplasts from P. vulgaris. The highly efficient polyethylene glycol-mannitol magnesium (PEG-MMG)-mediated transformation of leaf mesophyll protoplasts was optimized using a GUS reporter gene. We used the P. vulgaris SNF1-related protein kinase 1 (PvSnRK1) gene as proof of concept to demonstrate rapid gene functional analysis. An RT-qPCR analysis of protoplasts that had been transformed with PvSnRK1-RNAi and PvSnRK1-OE vectors showed the significant downregulation and ectopic constitutive expression (overexpression), respectively, of the PvSnRK1 transcript. We also demonstrated an improved transient transformation approach, sonication-assisted Agrobacterium-mediated transformation (SAAT), for the leaf disc infiltration of P. vulgaris. Interestingly, this method resulted in a 90 % transformation efficiency and transformed 60-85 % of the cells in a given area of the leaf surface. The constitutive expression of YFP further confirmed the amenability of the system to gene functional characterization studies. We present simple and efficient methodologies for protoplast isolation from multiple P

  18. The future for heavy crude oil

    Horsnell, P.

    1995-01-01

    The expectation, still held in 1993, that the light oil-heavy crude oil differential would go on increasing in favour of light oil has not been fulfilled. Current perceptions are that heavy oil will continue to be relatively strong and there is no inevitable upward trend in light-heavy crude differentials. Non-OPEC production has grown significantly lighter overall in recent years and is likely to continue so for several more years. This is due to expanded light oil production in the North Sea, Latin America and the Far East, and contractions in heavy oil production in Russia and the USA. OPEC production has also become lighter with, in particular, an expansion in light oil and contraction in heavy grades from Saudi Arabia. At the same time, the nature of the demand from refineries has changed with the introduction of new units designed to process the residium from heavy oil distillation. Thus the supply of light oil has expanded while demand for it has contracted with the reverse being true for heavy oil. (2 figures, 1 table) (UK)

  19. DOE turns down all bids for Elk Hills crude

    Anon.

    1992-01-01

    This paper reports that the U.S. Department of Energy has rejected all bids submitted in the Mar. 5 semiannual sale of crude oil from Elk Hills Naval Petroleum Reserve (NPR-1) in California. DOE the all 19 bids for the 53,740 b/d of crude were too low. The bids ranged from $11.71 to $14.06/bbl, with the top bids for the highest quality Stevens zone crude averaging $13.25/bbl. California oil companies the they bid what the market would bear, explaining a surplus of Alaskan crude on the West Coast has driven down the price of local crudes, notably heavy crudes. DOE will extend the current oil purchase contracts through April while it issues a new request for bids. It planned to issue the solicitation Mar. 23 and receive bids Apr. 15

  20. Patterns of indole alkaloids synthesis in response to heat shock, 5-azacytidine and Na-butyrate treatment of cultured catharanthus roseus mesophyll protoplasts

    Saleem, M.; Cutler, A.J.

    1986-01-01

    Alkaloids of C. roseus are in high demand for therapeutic and other reasons. Cultured Catharanthus cells can produce limited quantities of these alkaloids. The authors have found that cultured mesophyll protoplasts in the presence of 14 C-Tryptamine are capable of synthesizing alkaloids. The pattern of alkaloids synthesis changes when protoplasts are subjected to a heat shock at 37 0 C. The heat shocked protoplasts incorporated 33% more 14 C-Tryptamine and produced 3 new types of alkaloids. Treatment of protoplasts with 5-azacytidine, a DNA hypomethylating agent and Na-butyrate which induces hyperacetylation of histones produced qualitative and quantitative changes in the alkaloid pattern. Four new alkaloids following the above treatments were detected by TLC and HPLC of the extracts. It is suggested that the alkaloid pattern of the cultured protoplasts can be altered by treatment with compounds known as regulators of gene expression. Work is in progress to isolate and identify these new alkaloids

  1. RNA transcription in isolated chloroplasts during senescence and rejuvenation of intact cotyledons of CUCURBITA PEPO L. (ZUCCHINI)

    Mishev, K.; Ananiev, E.; Denev, L.; Radeva, G.

    2006-01-01

    RNA transcription was studied in intact chloroplasts isolated from cotyledons of Cucurbita pepoL. (zucchini) during their growth and development including natural senescence and rejuvenation. Rejuvenation of cotyledons was studied after decapitation of the epicotyl above the senescing yellow cotyledons. Maximal incorporation of [32P] UTP into overall chloroplast RNA was measured two days after exposure of seedlings to light (day 6 th after the onset of germination), followed by a gradual decrease reaching minimal values at the age of 25-28 days when cotyledons began to yellow and eventually die. Rejuvenation of cotyledons completely restored chloroplast RNA synthesis and fifteen days after decapitation (at the age of 40 days), the values of chloroplast transcription even exceeded that of the maximal transcriptional activity in young cotyledons. Inhibitory analysis with tagetitoxin (a specific inhibitor of plastid encoded chloroplast RNA polymerase (PEP)) showed that in young and rejuvenated cotyledons about 85% of chloroplast RNA polymerase activity was due to PEP and only 15% corresponded to the nuclear encoded plastid RNA polymerase (NEP). Definite regions of two chloroplast encoded genes were amplified by means of PCR technique using specific DNA primers for Rubisco large subunit gene (rbcL) and the housekeeping gene for chloroplast 16S rRNA as well as chloroplast DNA as a template. The appropriate lengths of the amplified DNA fragments were checked by restriction analysis

  2. Influence of the type of crude oil to platforming effects

    Kafedzhiski, Branko; Crvenkova, Suzana; Zikovski, Toni

    1999-01-01

    Platforming in one of the most subtleties processing in refinery industry and it is permanent source for research and finding out the higher optimum degree. Optimum of the last effects of platforming directly depends on many parameters. One of more important parameters is the type of crude. The purpose of this work is presenting positive and negative effect to the platforming parameters caused by different types of crude in OCTA-Crude Oil Refinery -Skopje, Macedonia. (Original)

  3. Influence of the crude oil type to platforming effects

    Kafedzhiski, Branko; Crvenkova, Suzana; Zikovski, Toni

    1999-01-01

    Platforming is one of the most subtleties processing in refinery industry and it is permanent source for research and finding out the higher optimum degree. Optimum of the last effects of platforming directly depends on many parameters. One of the more important parameters is the type of the crude. The purpose of this work is presenting positive and negative effect to the platforming parameters caused by different types of crude in OCTA Crude Oil Refinery - Skopje (Macedonia). (Author)

  4. Crude oil options market found to be efficient

    Anon.

    1992-01-01

    This paper reports that the U.S. crude oil options market operates efficiently and does not overreact. The authors, with the JFK School of Government, studied the crude oil options market under a Department of Energy grant. The current market was created in November 1986 when the New York Mercantile Exchange introduced an options contract for delivery of West Texas intermediate crude futures. it has grown greatly since then

  5. Increasing Leaf Vein Density via Mutagenesis in Rice Results in an Enhanced Rate of Photosynthesis, Smaller Cell Sizes and Can Reduce Interveinal Mesophyll Cell Number

    Aryo B. Feldman

    2017-11-01

    Full Text Available Improvements to leaf photosynthetic rates of crops can be achieved by targeted manipulation of individual component processes, such as the activity and properties of RuBisCO or photoprotection. This study shows that simple forward genetic screens of mutant populations can also be used to rapidly generate photosynthesis variants that are useful for breeding. Increasing leaf vein density (concentration of vascular tissue per unit leaf area has important implications for plant hydraulic properties and assimilate transport. It was an important step to improving photosynthetic rates in the evolution of both C3 and C4 species and is a foundation or prerequisite trait for C4 engineering in crops like rice (Oryza sativa. A previous high throughput screen identified five mutant rice lines (cv. IR64 with increased vein densities and associated narrower leaf widths (Feldman et al., 2014. Here, these high vein density rice variants were analyzed for properties related to photosynthesis. Two lines were identified as having significantly reduced mesophyll to bundle sheath cell number ratios. All five lines had 20% higher light saturated photosynthetic capacity per unit leaf area, higher maximum carboxylation rates, dark respiration rates and electron transport capacities. This was associated with no significant differences in leaf thickness, stomatal conductance or CO2 compensation point between mutants and the wild-type. The enhanced photosynthetic rate in these lines may be a result of increased RuBisCO and electron transport component amount and/or activity and/or enhanced transport of photoassimilates. We conclude that high vein density (associated with altered mesophyll cell length and number is a trait that may confer increased photosynthetic efficiency without increased transpiration.

  6. Crude oil pricing report, issue 89, December 1992

    1992-01-01

    This report is prepared by the Canadian Oil Markets and Emergency Planning Division (COMEP), Energy, Mines and Resources Canada. It provides a reference for domestic and imported crude oil prices in Canadian markets and illustrates the competitive position of Canadian crude in the U.S. market. The information in this report is in part based on the Crude Oil Pricing Survey (COPS), conducted by COMEP, of Canadian refiners' domestic crude oil purchases, refinery receipts, imports and data from trade publications as well as industry pricing bulletins. 8 tabs

  7. Chloroplasts as source and target of cellular redox regulation: a discussion on chloroplast redox signals in the context of plant physiology.

    Baier, Margarete; Dietz, Karl-Josef

    2005-06-01

    During the evolution of plants, chloroplasts have lost the exclusive genetic control over redox regulation and antioxidant gene expression. Together with many other genes, all genes encoding antioxidant enzymes and enzymes involved in the biosynthesis of low molecular weight antioxidants were transferred to the nucleus. On the other hand, photosynthesis bears a high risk for photo-oxidative damage. Concomitantly, an intricate network for mutual regulation by anthero- and retrograde signals has emerged to co-ordinate the activities of the different genetic and metabolic compartments. A major focus of recent research in chloroplast regulation addressed the mechanisms of redox sensing and signal transmission, the identification of regulatory targets, and the understanding of adaptation mechanisms. In addition to redox signals communicated through signalling cascades also used in pathogen and wounding responses, specific chloroplast signals control nuclear gene expression. Signalling pathways are triggered by the redox state of the plastoquinone pool, the thioredoxin system, and the acceptor availability at photosystem I, in addition to control by oxolipins, tetrapyrroles, carbohydrates, and abscisic acid. The signalling function is discussed in the context of regulatory circuitries that control the expression of antioxidant enzymes and redox modulators, demonstrating the principal role of chloroplasts as the source and target of redox regulation.

  8. Insights from the complete chloroplast genome into the evolution of Sesamum indicum L.

    Haiyang Zhang

    Full Text Available Sesame (Sesamum indicum L. is one of the oldest oilseed crops. In order to investigate the evolutionary characters according to the Sesame Genome Project, apart from sequencing its nuclear genome, we sequenced the complete chloroplast genome of S. indicum cv. Yuzhi 11 (white seeded using Illumina and 454 sequencing. Comparisons of chloroplast genomes between S. indicum and the 18 other higher plants were then analyzed. The chloroplast genome of cv. Yuzhi 11 contains 153,338 bp and a total of 114 unique genes (KC569603. The number of chloroplast genes in sesame is the same as that in Nicotiana tabacum, Vitis vinifera and Platanus occidentalis. The variation in the length of the large single-copy (LSC regions and inverted repeats (IR in sesame compared to 18 other higher plant species was the main contributor to size variation in the cp genome in these species. The 77 functional chloroplast genes, except for ycf1 and ycf2, were highly conserved. The deletion of the cp ycf1 gene sequence in cp genomes may be due either to its transfer to the nuclear genome, as has occurred in sesame, or direct deletion, as has occurred in Panax ginseng and Cucumis sativus. The sesame ycf2 gene is only 5,721 bp in length and has lost about 1,179 bp. Nucleotides 1-585 of ycf2 when queried in BLAST had hits in the sesame draft genome. Five repeats (R10, R12, R13, R14 and R17 were unique to the sesame chloroplast genome. We also found that IR contraction/expansion in the cp genome alters its rate of evolution. Chloroplast genes and repeats display the signature of convergent evolution in sesame and other species. These findings provide a foundation for further investigation of cp genome evolution in Sesamum and other higher plants.

  9. Fatty acid synthesis by spinach chloroplasts, 2. The path from PGA to fatty acids

    Yamada, Mitsuhiro; Nakamura, Yasunori [Tokyo Univ. (Japan). Coll. of General Education

    1975-02-01

    By incorporation of /sup 3/H/sub 2/O into the fatty acid chain in the presence of unlabelled precursor, we showed that fatty acids are synthesized from PGA, PEP and pyruvate by intact spinach chloroplasts in the light. /sup 13/C-tracer experiments confirmed that 1-C of pyruvate is decarboxylated and 2-C is incorporated into fatty acids by the chloroplasts. The patterns of fatty acids synthesized from PGA and pyruvate were the same as that from acetate. The highest rate of fatty acid synthesis was reached at the physiological concentration of PGA (3 mM) and pyruvate (1 mM). These results indicate the operation of the following path in the chloroplasts in light: PGA..-->..PEP..-->..pyruvate..-->..acetylCoA..-->..fatty acids. Since citrate and OAA were much less active and malate and glyoxylate were inert as precursors for fatty acid synthesis, PEP or pyruvate carboxylation, citrate lyase reaction and malate synthetase reaction are not involved in the formation of acetylCoA and fatty acids. Since pyruvate was much more effective as a substrate for fatty acid synthesis than lactate, acetaldehyde or acetate, direct decarboxylation path is considered to be the primary path from pyruvate to acetylCoA. The insignificant effect of chloroplast-washing on fatty acid synthesis from PGA and pyruvate indicates that the glycolytic path from PGA to pyruvate is associated with the chloroplasts. Since pyruvate was more effectively incorporated into fatty acids than acetylCoA, it is unlikely that pyruvate decarboxylation to acetylCoA is due to mitochondria contaminating the chloroplast preparation. On the basis of measurements of /sup 3/H/sub 2/O incorporation in the light and dark, the activity of fatty acid synthesis in spincah leaves appears to be shared by the activities in chloroplasts (87%) and other organelles (13%).

  10. The Complete Chloroplast Genome Sequences of Six Rehmannia Species

    Shuyun Zeng

    2017-03-01

    Full Text Available Rehmannia is a non-parasitic genus in Orobanchaceae including six species mainly distributed in central and north China. Its phylogenetic position and infrageneric relationships remain uncertain due to potential hybridization and polyploidization. In this study, we sequenced and compared the complete chloroplast genomes of six Rehmannia species using Illumina sequencing technology to elucidate the interspecific variations. Rehmannia plastomes exhibited typical quadripartite and circular structures with good synteny of gene order. The complete genomes ranged from 153,622 bp to 154,055 bp in length, including 133 genes encoding 88 proteins, 37 tRNAs, and 8 rRNAs. Three genes (rpoA, rpoC2, accD have potentially experienced positive selection. Plastome size variation of Rehmannia was mainly ascribed to the expansion and contraction of the border regions between the inverted repeat (IR region and the single-copy (SC regions. Despite of the conserved structure in Rehmannia plastomes, sequence variations provide useful phylogenetic information. Phylogenetic trees of 23 Lamiales species reconstructed with the complete plastomes suggested that Rehmannia was monophyletic and sister to the clade of Lindenbergia and the parasitic taxa in Orobanchaceae. The interspecific relationships within Rehmannia were completely different with the previous studies. In future, population phylogenomic works based on plastomes are urgently needed to clarify the evolutionary history of Rehmannia.

  11. Radiation inactivation analysis of chloroplast CF0-CF1 ATPase

    Wang, M.Y.; Chien, L.F.; Pan, R.L.

    1988-01-01

    Radiation inactivation technique was employed to measure the functional size of adenosine triphosphatase of spinach chloroplasts. The functional size for acid-base-induced ATP synthesis was 450 +/- 24 kilodaltons; for phenazine methosulfate-mediated ATP synthesis, 613 +/- 33 kilodaltons; and for methanol-activated ATP hydrolysis, 280 +/- 14 kilodaltons. The difference (170 +/- 57 kilodaltons) between 450 +/- 24 and 280 +/- 14 kilodaltons is explained to be the molecular mass of proton channel (coupling factor 0) across the thylakoid membrane. Our data suggest that the stoichiometry of subunits I, II, and III of coupling factor 0 is 1:2:15. Ca2+- and Mg2+-ATPase activated by methanol, heat, and trypsin digestion have a similar functional size. However, anions such as SO 3 (2-) and CO 3 (2-) increased the molecular mass for both ATPase's (except trypsin-activated Mg2+-ATPase) by 12-30%. Soluble coupling factor 1 has a larger target size than that of membrane-bound. This is interpreted as the cold effect during irradiation

  12. Stromal serine protein kinase activity in spinach chloroplasts

    Cortez, N.; Lucero, H.A.; Vallejos, R.H.

    1987-01-01

    At least twelve 32 P-labeled stromal proteins were detected by electrophoresis under denaturing conditions when intact chloroplasts were incubated with 32 Pi, in the light but only three were detected in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or in the dark. Incubation of isolated stroma with [gamma- 32 P]ATP resulted in the preferential phosphorylation of one of them, a 70-kDa polypeptide, in serine residues. Thylakoid membranes in the dark promoted the phosphorylation of two additional stromal polypeptides of 55 and 40 kDa. Illumination during the phosphorylation of stroma in the presence of thylakoids stimulated severalfold the labeling of the 40-kDa polypeptide but not when DCMU was added. The protein kinase activity present in isolated stroma phosphorylated exogenous substrates like histone III, phosvitin, histone II, and casein with specific activities of 3, 1.8, 0.7, and 0.2 pmol X mg-1 X min-1. Histone III polypeptides were phosphorylated differently by stroma and by thylakoids in the dark. Moreover, histone III phosphorylated by thylakoids in the dark yielded a pattern of phosphopeptides after V8 protease treatment that was different from the pattern obtained when histone III was phosphorylated by stroma

  13. Two complete chloroplast genome sequences of Cannabis sativa varieties.

    Oh, Hyehyun; Seo, Boyoung; Lee, Seunghwan; Ahn, Dong-Ha; Jo, Euna; Park, Jin-Kyoung; Min, Gi-Sik

    2016-07-01

    In this study, we determined the complete chloroplast (cp) genomes from two varieties of Cannabis sativa. The genome sizes were 153,848 bp (the Korean non-drug variety, Cheungsam) and 153,854 bp (the African variety, Yoruba Nigeria). The genome structures were identical with 131 individual genes [86 protein-coding genes (PCGs), eight rRNA, and 37 tRNA genes]. Further, except for the presence of an intron in the rps3 genes of two C. sativa varieties, the cp genomes of C. sativa had conservative features similar to that of all known species in the order Rosales. To verify the position of C. sativa within the order Rosales, we conducted phylogenetic analysis by using concatenated sequences of all PCGs from 17 complete cp genomes. The resulting tree strongly supported monophyly of Rosales. Further, the family Cannabaceae, represented by C. sativa, showed close relationship with the family Moraceae. The phylogenetic relationship outlined in our study is well congruent with those previously shown for the order Rosales.

  14. The complete chloroplast genome sequence of Abies nephrolepis (Pinaceae: Abietoideae

    Dong-Keun Yi

    2016-06-01

    Full Text Available The plant chloroplast (cp genome has maintained a relatively conserved structure and gene content throughout evolution. Cp genome sequences have been used widely for resolving evolutionary and phylogenetic issues at various taxonomic levels of plants. Here, we report the complete cp genome of Abies nephrolepis. The A. nephrolepis cp genome is 121,336 base pairs (bp in length including a pair of short inverted repeat regions (IRa and IRb of 139 bp each separated by a small single copy (SSC region of 54,323 bp (SSC and a large single copy region of 66,735 bp (LSC. It contains 114 genes, 68 of which are protein coding genes, 35 tRNA and four rRNA genes, six open reading frames, and one pseudogene. Seventeen repeat units and 64 simple sequence repeats (SSR have been detected in A. nephrolepis cp genome. Large IR sequences locate in 42-kb inversion points (1186 bp. The A. nephrolepis cp genome is identical to Abies koreana’s which is closely related to taxa. Pairwise comparison between two cp genomes revealed 140 polymorphic sites in each. Complete cp genome sequence of A. nephrolepis has a significant potential to provide information on the evolutionary pattern of Abietoideae and valuable data for development of DNA markers for easy identification and classification.

  15. Chloroplast DNA footprints of postglacial recolonization by oaks

    Petit, Rémy J.; Pineau, Emmanuel; Demesure, Brigitte; Bacilieri, Roberto; Ducousso, Alexis; Kremer, Antoine

    1997-01-01

    Recolonization of Europe by forest tree species after the last glaciation is well documented in the fossil pollen record. This spread may have been achieved at low densities by rare events of long-distance dispersal, rather than by a compact wave of advance, generating a patchy genetic structure through founder effects. In long-lived oak species, this structure could still be discernible by using maternally transmitted genetic markers. To test this hypothesis, a fine-scale study of chloroplast DNA (cpDNA) variability of two sympatric oak species was carried out in western France. The distributions of six cpDNA length variants were analyzed at 188 localities over a 200 × 300 km area. A cpDNA map was obtained by applying geostatistics methods to the complete data set. Patches of several hundred square kilometers exist which are virtually fixed for a single haplotype for both oak species. This local systematic interspecific sharing of the maternal genome strongly suggests that long-distance seed dispersal events followed by interspecific exchanges were involved at the time of colonization, about 10,000 years ago. PMID:11038572

  16. Artemisinin inhibits chloroplast electron transport activity: mode of action.

    Adyasha Bharati

    Full Text Available Artemisinin, a secondary metabolite produced in Artemisia plant species, besides having antimalarial properties is also phytotoxic. Although, the phytotoxic activity of the compound has been long recognized, no information is available on the mechanism of action of the compound on photosynthetic activity of the plant. In this report, we have evaluated the effect of artemisinin on photoelectron transport activity of chloroplast thylakoid membrane. The inhibitory effect of the compound, under in vitro condition, was pronounced in loosely and fully coupled thylakoids; being strong in the former. The extent of inhibition was drastically reduced in the presence of uncouplers like ammonium chloride or gramicidin; a characteristic feature described for energy transfer inhibitors. The compound, on the other hand, when applied to plants (in vivo, behaved as a potent inhibitor of photosynthetic electron transport. The major site of its action was identified to be the Q(B; the secondary quinone moiety of photosystemII complex. Analysis of photoreduction kinetics of para-benzoquinone and duroquinone suggest that the inhibition leads to formation of low pool of plastoquinol, which becomes limiting for electron flow through photosystemI. Further it was ascertained that the in vivo inhibitory effect appeared as a consequence of the formation of an unidentified artemisinin-metabolite rather than by the interaction of the compound per se. The putative metabolite of artemisinin is highly reactive in instituting the inhibition of photosynthetic electron flow eventually reducing the plant growth.

  17. Complete chloroplast genome sequence of a tree fern Alsophila spinulosa: insights into evolutionary changes in fern chloroplast genomes.

    Gao, Lei; Yi, Xuan; Yang, Yong-Xia; Su, Ying-Juan; Wang, Ting

    2009-06-11

    Ferns have generally been neglected in studies of chloroplast genomics. Before this study, only one polypod and two basal ferns had their complete chloroplast (cp) genome reported. Tree ferns represent an ancient fern lineage that first occurred in the Late Triassic. In recent phylogenetic analyses, tree ferns were shown to be the sister group of polypods, the most diverse group of living ferns. Availability of cp genome sequence from a tree fern will facilitate interpretation of the evolutionary changes of fern cp genomes. Here we have sequenced the complete cp genome of a scaly tree fern Alsophila spinulosa (Cyatheaceae). The Alsophila cp genome is 156,661 base pairs (bp) in size, and has a typical quadripartite structure with the large (LSC, 86,308 bp) and small single copy (SSC, 21,623 bp) regions separated by two copies of an inverted repeat (IRs, 24,365 bp each). This genome contains 117 different genes encoding 85 proteins, 4 rRNAs and 28 tRNAs. Pseudogenes of ycf66 and trnT-UGU are also detected in this genome. A unique trnR-UCG gene (derived from trnR-CCG) is found between rbcL and accD. The Alsophila cp genome shares some unusual characteristics with the previously sequenced cp genome of the polypod fern Adiantum capillus-veneris, including the absence of 5 tRNA genes that exist in most other cp genomes. The genome shows a high degree of synteny with that of Adiantum, but differs considerably from two basal ferns (Angiopteris evecta and Psilotum nudum). At one endpoint of an ancient inversion we detected a highly repeated 565-bp-region that is absent from the Adiantum cp genome. An additional minor inversion of the trnD-GUC, which is possibly shared by all ferns, was identified by comparison between the fern and other land plant cp genomes. By comparing four fern cp genome sequences it was confirmed that two major rearrangements distinguish higher leptosporangiate ferns from basal fern lineages. The Alsophila cp genome is very similar to that of the

  18. Complete chloroplast genome sequence of a tree fern Alsophila spinulosa: insights into evolutionary changes in fern chloroplast genomes

    Yang Yong-Xia

    2009-06-01

    Full Text Available Abstract Background Ferns have generally been neglected in studies of chloroplast genomics. Before this study, only one polypod and two basal ferns had their complete chloroplast (cp genome reported. Tree ferns represent an ancient fern lineage that first occurred in the Late Triassic. In recent phylogenetic analyses, tree ferns were shown to be the sister group of polypods, the most diverse group of living ferns. Availability of cp genome sequence from a tree fern will facilitate interpretation of the evolutionary changes of fern cp genomes. Here we have sequenced the complete cp genome of a scaly tree fern Alsophila spinulosa (Cyatheaceae. Results The Alsophila cp genome is 156,661 base pairs (bp in size, and has a typical quadripartite structure with the large (LSC, 86,308 bp and small single copy (SSC, 21,623 bp regions separated by two copies of an inverted repeat (IRs, 24,365 bp each. This genome contains 117 different genes encoding 85 proteins, 4 rRNAs and 28 tRNAs. Pseudogenes of ycf66 and trnT-UGU are also detected in this genome. A unique trnR-UCG gene (derived from trnR-CCG is found between rbcL and accD. The Alsophila cp genome shares some unusual characteristics with the previously sequenced cp genome of the polypod fern Adiantum capillus-veneris, including the absence of 5 tRNA genes that exist in most other cp genomes. The genome shows a high degree of synteny with that of Adiantum, but differs considerably from two basal ferns (Angiopteris evecta and Psilotum nudum. At one endpoint of an ancient inversion we detected a highly repeated 565-bp-region that is absent from the Adiantum cp genome. An additional minor inversion of the trnD-GUC, which is possibly shared by all ferns, was identified by comparison between the fern and other land plant cp genomes. Conclusion By comparing four fern cp genome sequences it was confirmed that two major rearrangements distinguish higher leptosporangiate ferns from basal fern lineages. The

  19. Geotechnical properties of crude oil contaminated sand

    Puri, V.K.; Das, B.M.; Cook, E.E.; Shin, E.C.

    1994-01-01

    Contamination of soil due to an oil spill influences its subsequent engineering behavior. An investigation was conducted to study the effect of crude oil contamination on compaction characteristics, shear strength, one-dimensional compression, and coefficient of permeability. Water permeability was also determined by using commercial grade motor oils as contaminants. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand (based on total stress condition) decreases due to presence of oil within the pore spaces in sand. One dimensional compression characteristics of sand are significantly influenced by oil contamination resulting in a decrease in the value of constrained modulus with increase in the degree of oil contamination compared to the case of dry sand. Water permeability was observed to be a function of the initial viscosity and the degree of saturation due to the contaminating oil

  20. Impact of Expanded North Slope of Alaska Crude Oil Production on Crude Oil Flows in the Contiguous United States

    DeRosa, Sean E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flanagan, Tatiana Paz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    The National Transportation Fuels Model was used to simulate a hypothetical increase in North Slope of Alaska crude oil production. The results show that the magnitude of production utilized depends in part on the ability of crude oil and refined products infrastructure in the contiguous United States to absorb and adjust to the additional supply. Decisions about expanding North Slope production can use the National Transportation Fuels Model take into account the effects on crude oil flows in the contiguous United States.

  1. Chemical composition of Pechora Sea crude oil

    Derkach S. R.

    2017-03-01

    Full Text Available The physicochemical properties of the Pechora Sea shelf oil and its chemical composition have been studied using the methods of refractometry, titrimetry, viscometry, rheometry and standard methods for the analysis of oil and petroleum products. The fractionation of oil is held at atmospheric pressure, some fractions boiling at the temperature below and above 211 °C have been received. Chemical structural-group composition of oil and its components has been investigated using a Fourier infrared (IR spectroscopy method. The density of oil has been obtained, it is equal to 24.2 API. The chemical composition analysis shows that water content in the investigated oil sample is about 0.03 % (by weight. The oil sample contains hydrocarbons (including alkanes, naphthenes, arenes and asphaltenes with resins; their content is equal to 89 and 10 % (by weight respectively. Alkane content is about 66 %, including alkanes of normal structure – about 37 %. The solidification temperature of oil sample is equal to –43 °C. This low temperature testifies obliquely low content of solid alkanes (paraffin. Bearing in mind the content of asphaltenes with resins we can refer the investigated oil sample to resinous oils. On the other hand spectral coefficient values (aromaticity quotient and aliphaticity quotient show that oil sample belongs to naphthenic oils. According to the data of Fourier IR spectroscopy contents of naphthenes and arenes are 5.9 and 17.8 % respectively. Thus, the obtained data of chemical structural-group composition of crude oil and its fractions indicate that this oil belongs to the heavy resinous naphthenic oils. The rheological parameters obtained at the shear deformation conditions characterize the crude oil as a visco-plastic medium.

  2. Dissecting the chloroplast proteome of chickpea (Cicer arietinum L.) provides new insights into classical and non-classical functions.

    Lande, Nilesh Vikram; Subba, Pratigya; Barua, Pragya; Gayen, Dipak; Keshava Prasad, T S; Chakraborty, Subhra; Chakraborty, Niranjan

    2017-08-08

    Chloroplast, the energy organelle unique to plant cells, is a dynamic entity which integrates an array of metabolic pathways and serves as first level for energy conversion for the entire ecological hierarchy. Increasing amount of sequence data and evolution of mass spectrometric approaches has opened up new avenues for opportune exploration of the global proteome of this organelle. In our study, we aimed at generation of a comprehensive catalogue of chloroplast proteins in a grain legume, chickpea and provided a reference proteome map. To accurately assign the identified proteins, purity of chloroplast-enriched fraction was stringently monitored by multiple chemical and immunological indexes, besides pigment and enzyme analyses. The proteome analysis led to the identification of 2451 proteins, including 27 isoforms, which include predicted and novel chloroplast constituents. The identified proteins were validated through their sequence analysis. Extensive sequence based localization prediction revealed more than 50% proteins to be chloroplast resident by at least two different algorithms. Chromosomal distribution of identified proteins across nuclear and chloroplast genome unveiled the presence of 55 chloroplast encoded gene. In depth comparison of our dataset with the non-redundant set of chloroplast proteins identified so far across other species revealed novel as well as overlapping candidates. Pulses add large amount of nitrogen to the soil and has very low water footprint and therefore, contributes to fortification of sustainable agriculture. Chickpea is one of the earliest cultivated legumes and serves as an energy and protein source for humans and animals. Chloroplasts are the unique organelles which conduct photosynthesis. Investigation on chloroplast proteome is of particular significance, especially to plant biologists, as it would allow a better understanding of chloroplast function in plants. Generation of a saturated proteome map would not only

  3. Expression of the Native Cholera Toxin B Subunit Gene and Assembly as Functional Oligomers in Transgenic Tobacco Chloroplasts

    Daniell, Henry; Lee, Seung-Bum; Panchal, Tanvi; Wiebe, Peter O.

    2012-01-01

    The B subunits of enterotoxigenic Escherichia coli (LTB) and cholera toxin of Vibrio cholerae (CTB) are candidate vaccine antigens. Integration of an unmodified CTB-coding sequence into chloroplast genomes (up to 10,000 copies per cell), resulted in the accumulation of up to 4.1% of total soluble tobacco leaf protein as functional oligomers (410-fold higher expression levels than that of the unmodified LTB gene expressed via the nuclear genome). However, expresssion levels reported are an underestimation of actual accumulation of CTB in transgenic chloroplasts, due to aggregation of the oligomeric forms in unboiled samples similar to the aggregation observed for purified bacterial antigen. PCR and Southern blot analyses confirmed stable integration of the CTB gene into the chloroplast genome. Western blot analysis showed that the chloroplast-synthesized CTB assembled into oligomers and were antigenically identical with purified native CTB. Also, binding assays confirmed that chloroplast- synthesized CTB binds to the intestinal membrane GM1-ganglioside receptor, indicating correct folding and disulfide bond formation of CTB pentamers within transgenic chloroplasts. In contrast to stunted nuclear transgenic plants, chloroplast transgenic plants were morphologically indistinguishable from untransformed plants, when CTB was constitutively expressed in chloroplasts. Introduced genes were inherited stably in subsequent generations, as confirmed by PCR and Southern blot analyses. Increased production of an efficient transmucosal carrier molecule and delivery system, like CTB, in transgenic chloroplasts makes plant-based oral vaccines and fusion proteins with CTB needing oral administration commercially feasible. Successful expression of foreign genes in transgenic chromoplasts and availability of marker-free chloroplast transformation techniques augurs well for development of vaccines in edible parts of transgenic plants. Furthermore, since the quaternary structure of

  4. Polyuridylylation and processing of transcripts from multiple gene minicircles in chloroplasts of the dinoflagellate Amphidinium carterae

    Barbrook, Adrian C.

    2012-05-05

    Although transcription and transcript processing in the chloroplasts of plants have been extensively characterised, the RNA metabolism of other chloroplast lineages across the eukaryotes remains poorly understood. In this paper, we use RT-PCR to study transcription and transcript processing in the chloroplasts of Amphidinium carterae, a model peridinin-containing dinoflagellate. These organisms have a highly unusual chloroplast genome, with genes located on multiple small \\'minicircle\\' elements, and a number of idiosyncratic features of RNA metabolism including transcription via a rolling circle mechanism, and 3′ terminal polyuridylylation of transcripts. We demonstrate that transcription occurs in A. carterae via a rolling circle mechanism, as previously shown in the dinoflagellate Heterocapsa, and present evidence for the production of both polycistronic and monocistronic transcripts from A. carterae minicircles, including several regions containing ORFs previously not known to be expressed. We demonstrate the presence of both polyuridylylated and non-polyuridylylated transcripts in A. carterae, and show that polycistronic transcripts can be terminally polyuridylylated. We present a model for RNA metabolism in dinoflagellate chloroplasts where long polycistronic precursors are processed to form mature transcripts. Terminal polyuridylylation may mark transcripts with the correct 3′ end. © 2012 Springer Science+Business Media B.V.

  5. Light-stimulated accumulation of transcripts of nuclear and chloroplast genes for ribulosebisphosphate carboxylase

    Smith, S M; Ellis, R J

    1981-01-01

    The chloroplast enzyme, ribulosebisphosphate carboxylase, consists of large subunit polypeptides encoded in the chloroplast genome and small subunit polypeptides encoded in the nuclear genome. Cloned DNA complementary to the small subunit mRNA hybridizes to a single RNA species of 900-1000 nucleotides in both total and poly(A)-containing RNA from leaves of Pisum sativum, but does not hybridize to chloroplast RNA. Small subunit cDNA hybridizes to at least three RNA species from nuclei, two of which are of higher molecular weight than the mature mRNA. A cloned large subunit DNA sequence hybridizes to a single species of Pisum chloroplast RNA containing approximately 1700 nucleotides, but does not hybridize to nuclear RNA. The light-stimulation of carboxylase accumulation reflects increases in the amounts of transcripts for both subunits in total leaf RNA. Transcripts of the small subunit gene are more abundant in nuclear RNA from light-grown leaves than in that from dark-grown leaves. These results suggest that the stimulation of carboxylase accumulation by light is mediated at the level of either transcription or RNA turnover in both nucleus and chloroplast.

  6. Is chloroplast import of photosynthesis proteins facilitated by an actin-TOC-TIC-VIPP1 complex?

    Jouhet, Juliette; Gray, John C

    2009-10-01

    Actin filaments are major components of the cytoskeleton that interact with chloroplast envelope membranes to allow chloroplast positioning and movement, stromule mobility and gravitropism perception. We recently reported that Toc159, a component of the TOC complex of the chloroplast protein import apparatus, interacts directly with actin. The interaction of Toc159 and actin was identified by co-immunoprecipitation and co-sedimentation experiments with detergent-solubilised pea chloroplast envelope membranes. In addition, many of the components of the TOC-TIC protein import apparatus and VIPP1 (vesicle-inducing protein in plastids 1) were identified by mass spectroscopy in the material co-immunoprecipitated with antibodies to actin. Toc159 is the receptor for the import of photosynthesis proteins and VIPP1 is involved in thylakoid membrane formation by inducing vesicle formation from the chloroplast inner envelope membrane, suggesting we may have identified an actin-TOC-TIC-VIPP1 complex that may provide a means of channeling cytosolic preproteins to the thylakoid membrane. The interaction of Toc159 with actin may facilitate exchange between the putative soluble and membrane forms of Toc159 and promote the interaction of cytosolic preproteins with the TOC complex.

  7. Chloroplast-Derived Vaccine Antigens and Biopharmaceuticals: Expression, Folding, Assembly and Functionality

    Chebolu, S.; Daniell, H.

    2009-01-01

    Chloroplast genetic engineering offers several advantages, including high levels of transgene expression, transgene containment via maternal inheritance, and multi-gene expression in a single transformation event. Oral delivery is facilitated by hyperexpression of vaccine antigens against cholera, tetanus, anthrax, plague, or canine parvovirus (4%–31% of total soluble protein, TSP) in transgenic chloroplasts (leaves) or non-green plastids (carrots, tomato) as well as the availability of antibiotic free selectable markers or the ability to excise selectable marker genes. Hyperexpression of several therapeutic proteins, including human serum albumin (11.1% TSP), somatotropin (7% TSP), interferon-alpha (19% TSP), interferon-gamma (6% TSP), and antimicrobial peptide (21.5% TSP), facilitates efficient and economic purification. Also, the presence of chaperones and enzymes in chloroplasts facilitates assembly of complex multisubunit proteins and correct folding of human blood proteins with proper disulfide bonds. Functionality of chloroplast-derived vaccine antigens and therapeutic proteins has been demonstrated by several assays, including the macrophage lysis assay, GM1-ganglioside binding assay, protection of HeLA cells or human lung carcinoma cells against encephalomyocarditis virus, systemic immune response, protection against pathogen challenge, and growth or inhibition of cell cultures. Purification of human proinsulin has been achieved using novel purification strategies (inverse temperature transition property) that do not require expensive column chromatography techniques. Thus, transgenic chloroplasts are ideal bioreactors for production of functional human and animal therapeutic proteins in an environmentally friendly manner. PMID:19401820

  8. The complete chloroplast genome of Cinnamomum camphora and its comparison with related Lauraceae species

    Caihui Chen

    2017-09-01

    Full Text Available Cinnamomum camphora, a member of the Lauraceae family, is a valuable aromatic and timber tree that is indigenous to the south of China and Japan. All parts of Cinnamomum camphora have secretory cells containing different volatile chemical compounds that are utilized as herbal medicines and essential oils. Here, we reported the complete sequencing of the chloroplast genome of Cinnamomum camphora using illumina technology. The chloroplast genome of Cinnamomum camphora is 152,570 bp in length and characterized by a relatively conserved quadripartite structure containing a large single copy region of 93,705 bp, a small single copy region of 19,093 bp and two inverted repeat (IR regions of 19,886 bp. Overall, the genome contained 123 coding regions, of which 15 were repeated in the IR regions. An analysis of chloroplast sequence divergence revealed that the small single copy region was highly variable among the different genera in the Lauraceae family. A total of 40 repeat structures and 83 simple sequence repeats were detected in both the coding and non-coding regions. A phylogenetic analysis indicated that Calycanthus is most closely related to Lauraceae, both being members of Laurales, which forms a sister group to Magnoliids. The complete sequence of the chloroplast of Cinnamomum camphora will aid in in-depth taxonomical studies of the Lauraceae family in the future. The genetic sequence information will also have valuable applications for chloroplast genetic engineering.

  9. Overoxidation of chloroplast 2-Cys peroxiredoxins: balancing toxic and signaling activities of hydrogen peroxide

    Leonor ePuerto-Galán

    2013-08-01

    Full Text Available Photosynthesis, the primary source of biomass and oxygen into the biosphere, involves the transport of electrons in the presence of oxygen and, therefore, chloroplasts constitute an important source of reactive oxygen species (ROS, including hydrogen peroxide. If accumulated at high level, hydrogen peroxide may exert a toxic effect; however, it is as well an important second messenger. In order to balance the toxic and signaling activities of hydrogen peroxide its level has to be tightly controlled. To this end, chloroplasts are equipped with different antioxidant systems such as 2-Cys peroxiredoxins (2-Cys Prxs, thiol-based peroxidases able to reduce hydrogen- and organic peroxides. At high peroxide concentrations the peroxidase function of 2-Cys Prxs may become inactivated through a process of overoxidation. This inactivation has been proposed to explain the signaling function of hydrogen peroxide in eukaryotes, whereas in prokaryotes, the 2-Cys Prxs of which were considered to be insensitive to overoxidation, the signaling activity of hydrogen peroxide is less relevant. Here we discuss the current knowledge about the mechanisms controlling 2-Cys Prx overoxidation in chloroplasts, organelles with an important signaling function in plants. Given the prokaryotic origin of chloroplasts, we discuss the occurrence of 2-Cys Prx overoxidation in cyanobacteria with the aim of identifying similarities between chloroplasts and their ancestors regarding their response to hydrogen peroxide.

  10. Discrete redox signaling pathways regulate photosynthetic light-harvesting and chloroplast gene transcription.

    John F Allen

    Full Text Available In photosynthesis in chloroplasts, two related regulatory processes balance the actions of photosystems I and II. These processes are short-term, post-translational redistribution of light-harvesting capacity, and long-term adjustment of photosystem stoichiometry initiated by control of chloroplast DNA transcription. Both responses are initiated by changes in the redox state of the electron carrier, plastoquinone, which connects the two photosystems. Chloroplast Sensor Kinase (CSK is a regulator of transcription of chloroplast genes for reaction centres of the two photosystems, and a sensor of plastoquinone redox state. We asked whether CSK is also involved in regulation of absorbed light energy distribution by phosphorylation of light-harvesting complex II (LHC II. Chloroplast thylakoid membranes isolated from a CSK T-DNA insertion mutant and from wild-type Arabidopsis thaliana exhibit similar light- and redox-induced (32P-labelling of LHC II and changes in 77 K chlorophyll fluorescence emission spectra, while room-temperature chlorophyll fluorescence emission transients from Arabidopsis leaves are perturbed by inactivation of CSK. The results indicate indirect, pleiotropic effects of reaction centre gene transcription on regulation of photosynthetic light-harvesting in vivo. A single, direct redox signal is transmitted separately to discrete transcriptional and post-translational branches of an integrated cytoplasmic regulatory system.

  11. Enzyme-Triggered Defined Protein Nanoarrays: Efficient Light-Harvesting Systems to Mimic Chloroplasts.

    Zhao, Linlu; Zou, Haoyang; Zhang, Hao; Sun, Hongcheng; Wang, Tingting; Pan, Tiezheng; Li, Xiumei; Bai, Yushi; Qiao, Shanpeng; Luo, Quan; Xu, Jiayun; Hou, Chunxi; Liu, Junqiu

    2017-01-24

    The elegance and efficiency by which chloroplasts harvest solar energy and conduct energy transfer have been a source of inspiration for chemists to mimic such process. However, precise manipulation to obtain orderly arranged antenna chromophores in constructing artificial chloroplast mimics was a great challenge, especially from the structural similarity and bioaffinity standpoints. Here we reported a design strategy that combined covalent and noncovalent interactions to prepare a protein-based light-harvesting system to mimic chloroplasts. Cricoid stable protein one (SP1) was utilized as a building block model. Under enzyme-triggered covalent protein assembly, mutant SP1 with tyrosine (Tyr) residues at the designated sites can couple together to form nanostructures. Through controlling the Tyr sites on the protein surface, we can manipulate the assembly orientation to respectively generate 1D nanotubes and 2D nanosheets. The excellent stability endowed the self-assembled protein architectures with promising applications. We further integrated quantum dots (QDs) possessing optical and electronic properties with the 2D nanosheets to fabricate chloroplast mimics. By attaching different sized QDs as donor and acceptor chromophores to the negatively charged surface of SP1-based protein nanosheets via electrostatic interactions, we successfully developed an artificial light-harvesting system. The assembled protein nanosheets structurally resembled the natural thylakoids, and the QDs can achieve pronounced FRET phenomenon just like the chlorophylls. Therefore, the coassembled system was meaningful to explore the photosynthetic process in vitro, as it was designed to mimic the natural chloroplast.

  12. The effect of UV-B radiation on chloroplast translation in Pisum sativum

    Raab, M.M.; Jagendorf, A.T.

    1990-01-01

    UV-B radiation has previously been reported to reduce growth, flowering, and net photosynthesis. The present study examines the effect of UV-B radiation on isolated chloroplast of 7-10 day old pea seedlings. Amount of ( 3 H)-Leu incorporated into isolated chloroplasts was measured in the presence or absence of UV-B exposure. Preliminary experiments show a 30% inhibition of protein synthesis in isolated chloroplasts after only 20 mins of UV-B exposure (6.9 J/m 2 /30 min). Percent inhibition of chloroplast translation is directly correlated with UV-B exposure over a 60 min time span. Preliminary studies also show no change in both cold and radiolabeled protein profiles as expressed on 1-D PAGE and autofluorography. Comparative studies on the sensitivity of e - flow vs protein synthesis following UV-B exposure are underway. Further work on the role of oxygen free radicals and the specific site of action of UV-B damage to the translation machinery of chloroplasts will be discussed

  13. Purification of intact chloroplasts from marine plant Posidonia oceanica suitable for organelle proteomics.

    Piro, Amalia; Serra, Ilia Anna; Spadafora, Antonia; Cardilio, Monica; Bianco, Linda; Perrotta, Gaetano; Santos, Rui; Mazzuca, Silvia

    2015-12-01

    Posidonia oceanica is a marine angiosperm, or seagrass, adapted to grow to the underwater life from shallow waters to 50 m depth. This raises questions of how their photosynthesis adapted to the attenuation of light through the water column and leads to the assumption that biochemistry and metabolism of the chloroplast are the basis of adaptive capacity. In the present study, we described a protocol that was adapted from those optimized for terrestrial plants, to extract chloroplasts from as minimal tissue as possible. We obtained the best balance between tissue amount/intact chloroplasts yield using one leaf from one plant. After isopynic separations, the chloroplasts purity and integrity were evaluated by biochemical assay and using a proteomic approach. Chloroplast proteins were extracted from highly purified organelles and resolved by 1DE SDS-PAGE. Proteins were sequenced by nLC-ESI-IT-MS/MS of 1DE gel bands and identified against NCBInr green plant databases, Dr. Zompo database for seagrasses in a local customized dataset. The curated localization of proteins in sub-plastidial compartments (i.e. envelope, stroma and thylakoids) was retrieved in the AT_CHLORO database. This purification protocol and the validation of compartment markers may serve as basis for sub-cellular proteomics in P. oceanica and other seagrasses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Effects of lead on enzymes of porphyrine biosynthesis in chloroplasts and erythrocytes

    Hampp, R.; Kriebitzsch, C.; Ziegler, H.

    1974-01-01

    Two enzymes of the chlorophyll biosynthesis pathway, delta-aminolevulinic acid dehydratase (ALAD) and prophobilinogenase (PBGA), show a pronounced sensitivity to lead ion, as was shown in isolated chloroplasts of spinach. It has been reported by several authors that the activity of ALAD involved in the hemoglobine-biosynthesis in erythrocytes is also very sensitive to lead ions. Spinach chloroplasts were isolated and sonicated and the enzyme activity tested. Calf blood was collected with heparin and kept at 0/sup 0/C until enzyme determination. Hemolyzed erythrocytes (rapid freezing and thawing twice) were used as the source of enzymes. The incubation mixture was the same as for chloroplasts; the hemoglobin content per test was about 44 mg (ALAD) and 91 mg (PBGA). ALAD in erythrocytes is somewhat more sensitive to lead ions than ALAD in chloroplasts. PBGA in erythrocytes is also inhibited by Pb/sup 2 +/ ions, again more than the chloroplast enzyme. At all concentrations of Pb/sup 2 +/ checked in our experiments the percentage of inhibition was higher with PBGA. 3 references, 1 figure.

  15. Fungitoxic properties of four crude plant extacts on fusarium ...

    Fungitoxic properties of four crude plant extacts on fusarium oxysporum schl. F. sp phaseoli. ... African Journal of Food, Agriculture, Nutrition and Development ... Crude plant extracts from Azadirachta indica, Tagetes minuta, Nicotiana tobacum and Vinca rosea were tested against Fusarium oxysporum Schl. F. sp. phaseoli.

  16. Comparative ovulation in clariidae using crude HCG from early ...

    This paper used purified crude HCG from early pregnancy urine to assay ovulation in three species of Clariidae. Purification and extraction of crude HCG was carried out by the techniques involving alcohol precipitation, ion exchange chromatography and gel filtration. Biological activity of the purified homogenate was tested ...

  17. Comparative study of biodegradation of crude oil in soil amended ...

    Analysis of soil samples treated with 10% (v/w) Escravos light crude oil and amended with chicken droppings and NPK fertilizer revealed that the aerobic heterotrophic bacterial counts were depressed while the proliferation of crude oil degrading bacteria (CDB) in the soil was encouraged. The counts of CDB in oil free ...

  18. Crude oil degradation by Bacillus and Micrococcus species isolated ...

    Microorganisms capable of degrading crude oil were isolated from soil compost in Kano, northwestern Nigeria. The work was carried out with the aim of determining crude-oil biodegradation potentials of Bacillus and Micrococcus species isolated from the soil compost as well as the assessment of the applicability of ...

  19. Pilot scale refinning of crude soybean oil | Mensah | Journal of ...

    Pilot scale refinning of crude soybean oil. ... Abstract. A laboratory process for refining soybean has been scaled up to a 145 tonne per annum pilot plant to refine crude soybean oil. ... The quality of the refined oil was found to be within national and codex standard specifications for edible oil from vegetable sources.

  20. Expanding U.S. markets for Canadian crude oil

    Heath, M.; Angevine, G.; Chan, K.; Renne, G.; Stariha, J.; MacKay, E.

    1993-01-01

    The quantities and types of Canadian, U.S. and competing foreign crudes flowing into U.S. market regions and the potential to retain and/or expand Canadian crude oil sales in each of those markets, was studied. The various pipeline system expansion/construction proposals were reviewed. Findings of the study with respect to prospects for crude oil sales into each of the U.S. market regions were presented. Opportunities and constraints with regard to the potential for incremental crude oil sales into each of the U.S. market regions were detailed. The study concluded that there was a substantial market in the U.S. for incremental sales of Canadian crudes. Most of the refineries in the U.S. market regions were more flexible in terms of their crude diet than they were before the rationalization and restructuring of the industry began. The market for crude oil in the U.S. was shown to be one of the most competitive in the world and the most volatile. The study also revealed that there were risks associated with large additions to the capacity to ship crude oil by pipeline from Western Canada, given the uncertainties surrounding future supply. 4 refs., figs., tabs

  1. Phytochemical and anti-fungal activity of crude extracts, fractions ...

    The Minimum Inhibitory Concentrations (MIC) of the crude extracts, fractions and isolated compound were determined by agardilution. Bioassay-guided fractionation of the crude extracts was carried out using column chromatography. Results: The phytochemical screening revealed the presence of alkaloids, cardenolides, ...

  2. Remediation trials of crude oil contaminated soil using different ...

    A 3 month remediation trial of the use of detergent and sawdust in different combination forms in the restoration of a crude oil contaminated tropical soil was investigated. 8 remediation treatments labeled A – H in addition to the control (I) were used in 10 kg soil artificially polluted with 300 ml crude oil each. Remediation ...

  3. Toxicity of crude oil products and detergent on serum alkaline ...

    The comparative effect of exposing Clarias gariepinus juveniles (100.20 + 0.8g) to diferent concentrations of crude oil products and detergent were studied. Bonny Light Crude oil (BLCO), Premium motor spirit (PMS), Dual purpose kerosene (DPK) and Ariel Enzymax Detergent (AED) were respectively applied at three ...

  4. Biodegradability Of The Major Components Of Bonny Light Crude ...

    Of the known 92 potential hydrocarbon-utilizing bacteria and fungi isolated from crude oil polluted soil and water samples, only one soil bacterial isolate (SB17), identified as Bacillus subtilis, was found to efficiently degrade 72.23% of the Bonny light crude oil sample after 25 days of incubation, and thus was used for further ...

  5. Assessment of the hydrolytic performance of locally sourced crude ...

    amylases increased with increase in substrate concentration up to a maximum substrate concentration of 10%. The crude alpha amylase exhibited a dextrinization time of 2.5h, 2.75h and 3.0h for maize, cassava and potato starches and produced 13%, 12% and 11.8% glucose respectively. The crude gluco-amylase had ...

  6. Manihot esculenta crantz in crude oil contaminated soil amended ...

    Studies on the performance of Manihot esculenta, Crantz (TMS 30572) in a crude oil polluted soil was investigated in the Botanic Garden of University of Port Harcourt. The soil samples were polluted at four different levels (0%, 2%, 4% and 6%) with crude oil and amended with organic supplement (decomposed Centrosem ...

  7. Some Neuropharmacological Effects of the Crude Venom Extract of ...

    This study reports some neuropharmacological effects of the crude venom extract of Conus musicus (family Conidae) in mice using various experimental models. The crude venom was found to significantly increase tail flick reaction time in mice. The effects of the venom on the central nervous system were studied by ...

  8. Effect of mushroom ( Pleurotus tuber-regium ) inoculums on crude ...

    Pollution of soils by crude oil in Niger-Delta of Nigeria has brought untold hardship to the inhabitants of the region. This study was carried out in 2010/2011 and 2011/2012 to determine the effect of Pleurotus tuber-regium (mushroom) inoculums on crude oil polluted soil on stover and grain yields and as well as cob length ...

  9. Influence of crude extract of root of Telfairia occidentalis (fluted ...

    The effect of crude extract of root of Telfairia occidentalis (fluted pumpkin) was investigated on the kidney of adult wistar rats. The crude extract of pumpkin root were given both intraperitoneally and orally to rats respectively. The control group received distilled water throughout the duration of experiment. The administration ...

  10. Improving Aspergillus carbonarius crude enzymes for lignocellulose hydrolysis

    Hansen, Gustav Hammerich

    and single enzyme supplementation. Fungal strains were screened in order to determine crude enzyme extracts that could be supplemented as boosters of A. carbonarius own crude enzyme extract, when applied in lignocellulose hydrolysis. The fungi originated from different environmental niches, which all had...... for their potential in hydrolysis of wheat straw both by application of monocultures and by supplementing to crude enzymes of A. carbonarius. For the crude enzymes from solid cultivations there were eight isolates that showed synergistic interaction resulting in doubling and tripling of the glucose release in wheat...... straw hydrolysis. A completely different profile of synergy was observed for crude enzymes from liquid cultivations, as there were only three isolates that enhanced glucose release. Only one of these three isolates had shown synergistic effects when cultivated in a solid medium. The screening...

  11. Lyondell plans to hike heavy crude runs at Houston

    Land, R.

    1992-01-01

    Lyondell Petrochemical Co. has outlined a venture that would allow increased runs of heavy crude oil at its 265,000 b/cd Houston refiner. Preliminary plans call for Lyondell, Houston, to ally with subsidiaries of Venezuela's Petroleos de Venezuela SA to upgrade heavy crude processing capabilities of the refiner and obtain supplies of heavy crude feedstock. Lyondell proposes to form a jointly owned company with Pdvsa's Citgo Petroleum Corp. subsidiary to take over ownership of the Houston plant. This paper reports that upgrades would not significantly change the plant's crude capacity but would allow the refiner to process as much as 200,000 b/d of heavy crude feedstock, up from 120,000 b/d at present. Following completion of the upgrade, Citgo could increase its interest to 50% with Lyondell retaining remaining venture interest. Upgrade design and engineering are to begin immediately, with regulatory permitting and construction expected to be complete in 3-4 years

  12. Chloroplast genome evolution in early diverged leptosporangiate ferns.

    Kim, Hyoung Tae; Chung, Myong Gi; Kim, Ki-Joong

    2014-05-01

    In this study, the chloroplast (cp) genome sequences from three early diverged leptosporangiate ferns were completed and analyzed in order to understand the evolution of the genome of the fern lineages. The complete cp genome sequence of Osmunda cinnamomea (Osmundales) was 142,812 base pairs (bp). The cp genome structure was similar to that of eusporangiate ferns. The gene/intron losses that frequently occurred in the cp genome of leptosporangiate ferns were not found in the cp genome of O. cinnamomea. In addition, putative RNA editing sites in the cp genome were rare in O. cinnamomea, even though the sites were frequently predicted to be present in leptosporangiate ferns. The complete cp genome sequence of Diplopterygium glaucum (Gleicheniales) was 151,007 bp and has a 9.7 kb inversion between the trnL-CAA and trnVGCA genes when compared to O. cinnamomea. Several repeated sequences were detected around the inversion break points. The complete cp genome sequence of Lygodium japonicum (Schizaeales) was 157,142 bp and a deletion of the rpoC1 intron was detected. This intron loss was shared by all of the studied species of the genus Lygodium. The GC contents and the effective numbers of codons (ENCs) in ferns varied significantly when compared to seed plants. The ENC values of the early diverged leptosporangiate ferns showed intermediate levels between eusporangiate and core leptosporangiate ferns. However, our phylogenetic tree based on all of the cp gene sequences clearly indicated that the cp genome similarity between O. cinnamomea (Osmundales) and eusporangiate ferns are symplesiomorphies, rather than synapomorphies. Therefore, our data is in agreement with the view that Osmundales is a distinct early diverged lineage in the leptosporangiate ferns.

  13. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

    Heubl Günther

    2010-11-01

    Full Text Available Abstract Background In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past. Results Our analysis of the rapidly evolving trnK/matK, trnL-F and rps16 chloroplast regions enabled us to infer more precise phylogenetic hypotheses for the Lamiales. Relationships among the nine first-branching families in the Lamiales tree are now resolved with very strong support. Subsequent to Plocospermataceae, a clade consisting of Carlemanniaceae plus Oleaceae branches, followed by Tetrachondraceae and a newly inferred clade composed of Gesneriaceae plus Calceolariaceae, which is also supported by morphological characters. Plantaginaceae (incl. Gratioleae and Scrophulariaceae are well separated in the backbone grade; Lamiaceae and Verbenaceae appear in distant clades, while the recently described Linderniaceae are confirmed to be monophyletic and in an isolated position. Conclusions Confidence about deep nodes of the Lamiales tree is an important step towards understanding the evolutionary diversification of a major clade of flowering plants. The degree of resolution obtained here now provides a first opportunity to discuss the evolution of morphological and biochemical traits in Lamiales. The multiple independent evolution of the carnivorous syndrome, once in Lentibulariaceae and a second time in Byblidaceae, is strongly supported by all analyses and topological tests. The evolution of selected morphological characters such as flower symmetry is discussed. The addition of further sequence data from introns and spacers holds promise to eventually obtain a

  14. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

    2010-01-01

    Background In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past. Results Our analysis of the rapidly evolving trnK/matK, trnL-F and rps16 chloroplast regions enabled us to infer more precise phylogenetic hypotheses for the Lamiales. Relationships among the nine first-branching families in the Lamiales tree are now resolved with very strong support. Subsequent to Plocospermataceae, a clade consisting of Carlemanniaceae plus Oleaceae branches, followed by Tetrachondraceae and a newly inferred clade composed of Gesneriaceae plus Calceolariaceae, which is also supported by morphological characters. Plantaginaceae (incl. Gratioleae) and Scrophulariaceae are well separated in the backbone grade; Lamiaceae and Verbenaceae appear in distant clades, while the recently described Linderniaceae are confirmed to be monophyletic and in an isolated position. Conclusions Confidence about deep nodes of the Lamiales tree is an important step towards understanding the evolutionary diversification of a major clade of flowering plants. The degree of resolution obtained here now provides a first opportunity to discuss the evolution of morphological and biochemical traits in Lamiales. The multiple independent evolution of the carnivorous syndrome, once in Lentibulariaceae and a second time in Byblidaceae, is strongly supported by all analyses and topological tests. The evolution of selected morphological characters such as flower symmetry is discussed. The addition of further sequence data from introns and spacers holds promise to eventually obtain a fully resolved plastid tree of

  15. Specific and efficient targeting of cyanobacterial bicarbonate transporters to the inner envelope membrane of chloroplasts in Arabidopsis

    Susumu eUehara

    2016-02-01

    Full Text Available Installation of cyanobacterial bicarbonate transporters to the inner envelope membrane (IEM of chloroplasts in C3 plants has been thought to improve photosynthetic performance. However, the method to deliver cyanobacterial bicarbonate transporters to the chloroplast IEM remains to be established. In this study, we provide evidence that the cyanobacterial bicarbonate transporters, BicA and SbtA, can be specifically installed into the chloroplast IEM using the chloroplast IEM targeting signal in conjunction with the transit peptide. We fused the transit peptide and the mature portion of Cor413im1, whose targeting mechanism to the IEM has been characterized in detail, to either BicA or SbtA isolated from Synechocystis sp. PCC6803. Among the seven chimeric constructs tested, we confirmed that four chimeric bicarbonate transporters, designated as BicAI, BicAII, SbtAII, and SbtAIII, were expressed in Arabidopsis. Furthermore, these chimeric transporters were specifically targeted to the chloroplast IEM. They were also resistant to alkaline extraction but can be solubilized by Triton X-100, indicating that they are integral membrane proteins in the chloroplast IEM. One of the transporters, BicA, could reside in the chloroplast IEM even after removal of the IEM targeting signal. Taken together, our results indicate that the addition of IEM targeting signal, as well as the transit peptide, to bicarbonate transporters allows us to efficiently target nuclear-encoded chimeric bicarbonate transporters to the chloroplast IEM.

  16. The novel chloroplast outer membrane kinase KOC1 is a required component of the plastid protein import machinery.

    Zufferey, Mónica; Montandon, Cyrille; Douet, Véronique; Demarsy, Emilie; Agne, Birgit; Baginsky, Sacha; Kessler, Felix

    2017-04-28

    The biogenesis and maintenance of cell organelles such as mitochondria and chloroplasts require the import of many proteins from the cytosol, a process that is controlled by phosphorylation. In the case of chloroplasts, the import of hundreds of different proteins depends on translocons at the outer and inner chloroplast membrane (TOC and TIC, respectively) complexes. The essential protein TOC159 functions thereby as an import receptor. It has an N-terminal acidic (A-) domain that extends into the cytosol, controls receptor specificity, and is highly phosphorylated in vivo However, kinases that phosphorylate the TOC159 A-domain to enable protein import have remained elusive. Here, using co-purification with TOC159 from Arabidopsis , we discovered a novel component of the chloroplast import machinery, the regulatory kinase at the outer chloroplast membrane 1 (KOC1). We found that KOC1 is an integral membrane protein facing the cytosol and stably associates with TOC. Moreover, KOC1 phosphorylated the A-domain of TOC159 in vitro , and in mutant koc1 chloroplasts, preprotein import efficiency was diminished. koc1 Arabidopsis seedlings had reduced survival rates after transfer from the dark to the light in which protein import into plastids is required to rapidly complete chloroplast biogenesis. In summary, our data indicate that KOC1 is a functional component of the TOC machinery that phosphorylates import receptors, supports preprotein import, and contributes to efficient chloroplast biogenesis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. β-Carotene as a factor in the reconstitution of cyclic phospho rylation in damaged chloroplast membranes

    Anna Tukendorf

    2014-01-01

    Full Text Available Phenazine methosulphate mediated cyclic phosphorylation suppressed by heptane extraction or galactolipase treatment of spinach chloroplasts is restored by β -carotene, in 100% and 50%, respectively. Xanthophylls are not able to reconstitute this reaction. β-Carotene replaces galactolipids in reactivation of galactolipase treated chloroplasts, indicating a nonspecific effect of lipids in photosystem I dependent reactions.

  18. Crude oil prices: Speculation versus fundamentals

    Kolodziej, Marek Krzysztof

    Beginning in 2004, the price of crude oil fluctuates rapidly over a wide range. Large and rapid price increases have recessionary consequences and dampen long-term infrastructural investment. I investigate whether price changes are driven by market fundamentals or speculation. With regard to market fundamentals, I revisit econometric evidence for the importance of demand shocks, as proxied by dry maritime cargo rates, on oil prices. When I eliminate transportation costs from both sides of the equation, disaggregate OPEC and non-OPEC production, and allow for more than one cointegrating relation, I find that previous specifications are inconsistent with arguments that demand shocks play an important role. Instead, results confirm the importance of OPEC supply shocks. I investigate two channels by which speculation may affect oil prices; the direct effect of trader behavior and changes in oil from a commodity to a financial asset. With regard to trader behavior, I find evidence that trader positions are required to explain the spread between spot and futures prices of crude oil on the New York Mercantile Exchange. The inclusion of trader positions clarifies the process of equilibrium error correction, such that there is bidirectional causality between prices and trader positions. This creates the possibility of speculative bubbles. With regard to oil as a commodity and/or financial asset, I use a Kalman Filter model to estimate the time-varying partial correlation between returns to investments in equity and oil markets. This correlation changes from negative to positive at the onset of the 2008 financial crisis. The low interest rates used to rescue the economy depress convenience yields, which reduces the benefits of holding oil as a commodity. Instead, oil becomes a financial asset (on net) as the oil market changed from contango to backwardation. Contradicting simple political narratives, my research suggests that both market fundamentals and speculation drive

  19. Formation and Change of Chloroplast-Located Plant Metabolites in Response to Light Conditions

    Yiyong Chen

    2018-02-01

    Full Text Available Photosynthesis is the central energy conversion process for plant metabolism and occurs within mature chloroplasts. Chloroplasts are also the site of various metabolic reactions involving amino acids, lipids, starch, and sulfur, as well as where the production of some hormones takes place. Light is one of the most important environmental factors, acting as an essential energy source for plants, but also as an external signal influencing their growth and development. Plants experience large fluctuations in the intensity and spectral quality of light, and many attempts have been made to improve or modify plant metabolites by treating them with different light qualities (artificial lighting or intensities. In this review, we discuss how changes in light intensity and wavelength affect the formation of chloroplast-located metabolites in plants.

  20. Effect of gamma irradiation of some quantitative indices of wheat and the ultrastructure of wheat chloroplasts

    Petrovic, J; Marek, J; Hraska, S [Vysoka Skola Polnohospodarska, Nitra (Czechoslovakia). Katedra Slachtenia a Obrany Rastlin

    1977-01-01

    The effects were observed of acute gamma irradiation on dry seeds of Triticum aestivum var. erythrospermum (Koern.) Mansf., variety Kosutska, and Triticum monococcum (L.). Gamma radiation doses ranged from 0.258 C.kg/sup -1/ (1 kR) to 5.160 C.kg/sup -1/ (20 kR). Plant samples from pot experiments were analyzed as to the lengths of the first three leaves, production of dry matter and chloroplast ultrastructure. The studied quantitative indices, their variability and correlations are substantially dependent on the genotype of the tested species and on the applied radiation dose. Gamma radiation caused vesiculation and increase of chloroplasts, an increase in the grain number, a decline in the number of disks, a reduction of stroma thylakoids and a grouping of grana in the chloroplasts. The frequency of these changes is significantly influenced by the genotype of the tested species and by the applied radiation dose level.

  1. Expression and Chloroplast Targeting of Cholesterol Oxidase in Transgenic Tobacco Plants

    Corbin, David R.; Grebenok, Robert J.; Ohnmeiss, Thomas E.; Greenplate, John T.; Purcell, John P.

    2001-01-01

    Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues expressing cholesterol oxidase exerted insecticidal activity against boll weevil larvae. Our results indicate that cholesterol oxidase can metabolize phytosterols in vivo when produced cytosolically or when targeted to chloroplasts. The transgenic plants exhibiting cytosolic expression accumulated low levels of saturated sterols known as stanols, and displayed severe developmental aberrations. In contrast, the transgenic plants expressing chloroplast-targeted cholesterol oxidase maintained a greater accumulation of stanols, and appeared phenotypically and developmentally normal. These results are discussed within the context of plant sterol distribution and metabolism. PMID:11457962

  2. Development of 12 Chloroplast Microsatellite Markers in Vigna unguiculata (Fabaceae and Amplification in Phaseolus vulgaris

    Lei Pan

    2014-03-01

    Full Text Available Premise of the study: Vigna unguiculata is an economically important legume, and the complexity of its variability and evolution needs to be further understood. Based on publicly available databases, we developed chloroplast microsatellite primers to investigate genetic diversity within V. unguiculata and its related species Phaseolus vulgaris. Methods and Results: Twelve polymorphic chloroplast microsatellite markers were developed and characterized in 62 V. unguiculata individuals. The number of alleles per locus varied between two and four, the unbiased haploid diversity per locus ranged from 0.123 to 0.497, and the polymorphism information content varied from 0.114 to 0.369. In cross-species amplifications, nine of these markers showed polymorphism in 29 P. vulgaris individuals. Conclusions: The newly developed chloroplast microsatellite markers exhibit variation in V. unguiculata as well as their transferability in P. vulgaris. These markers can be used to investigate genetic diversity and evolution in V. unguiculata and P. vulgaris.

  3. The complete chloroplast genome of a medicinal plant Epimedium koreanum Nakai (Berberidaceae).

    Lee, Jung-Hoon; Kim, Kyunghee; Kim, Na-Rae; Lee, Sang-Choon; Yang, Tae-Jin; Kim, Young-Dong

    2016-11-01

    Epimedium koreanum is a perennial medicinal plant distributed in Eastern Asia. The complete chloroplast genome sequences of E. koreanum was obtained by de novo assembly using whole genome next-generation sequences. The chloroplast genome of E. koreanum was 157 218 bp in length and separated into four distinct regions such as large single copy region (89 600 bp), small single copy region (17 222 bp) and a pair of inverted repeat regions (25 198 bp). The genome contained a total of 112 genes including 78 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis with the reported chloroplast genomes revealed that E. koreanum is most closely related to Berberis bealei, a traditional medicinal plant in the Berberidaceae family.

  4. Efficient way of importing crude oil from oil producing countries - A review on diversification policy of crude oil import

    Lee, Dal Sok [Korea Energy Economics Institute, Euiwang (Korea)

    1999-03-01

    Since the second oil crisis, the government has operated the import diversification support program to reduce the risk of crude oil import from Middle-East region and to raise the ability of dealing with the risk. This study tried to seek policy trends in future through reviewing the market environment related to the crude oil import diversification policy and the goal, instrument and effect of the policy. The supply and demand of crude oil and the price are influenced by market system in the world oil market and there are various types of crude oil trading available to both sellers and buyers. There is a probability that the suspension of supply in a certain area could be led to the price issue rather than the physical use of crude oil. In addition, the advantage of price with long-term contract of crude oil was abolished since the price of crude oil imported by term contract has been linked to spot prices. As a result, it is shown that the potential benefit from crude oil import diversification policy is reduced although political and social insecurity still exists in Middle-East region. Therefore, it is desirable to maintain the existing support program until the amount of stored oil reaches the optimum level and to help private enterprises determine the import considering economical efficiency and risk. (author). 36 refs., 5 figs., 23 tabs.

  5. Conversion of yellow crude sugar into alcohol. Conversion of yellow crude sugar in a mixture with sugar beet molasses

    Krishtul, F B; Malchenko, A L; Poluyanova, M T; Gromovich, V F; Maskimova, E A; Golodovskaya, A I; Pal' gova, L S

    1963-01-01

    Crude sugar (96.5 to 98.4% sucrose) in a mixture with molasses can be converted into alcohol by either batchwise or continuous fermentation processes with good process characteristics. Best yields are obtained when the amount of crude sugar is not more than 50% of the total weight of fermenting material. The bakers' yeast and alcohol produced are of good quality.

  6. The KAC family of kinesin-like proteins is essential for the association of chloroplasts with the plasma membrane in land plants.

    Suetsugu, Noriyuki; Sato, Yoshikatsu; Tsuboi, Hidenori; Kasahara, Masahiro; Imaizumi, Takato; Kagawa, Takatoshi; Hiwatashi, Yuji; Hasebe, Mitsuyasu; Wada, Masamitsu

    2012-11-01

    Chloroplasts require association with the plasma membrane for movement in response to light and for appropriate positioning within the cell to capture photosynthetic light efficiently. In Arabidopsis, CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1), KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT 1 (KAC1) and KAC2 are required for both the proper movement of chloroplasts and the association of chloroplasts with the plasma membrane, through the reorganization of short actin filaments located on the periphery of the chloroplasts. Here, we show that KAC and CHUP1 orthologs (AcKAC1, AcCHUP1A and AcCHUP1B, and PpKAC1 and PpKAC2) play important roles in chloroplast positioning in the fern Adiantum capillus-veneris and the moss Physcomitrella patens. The knockdown of AcKAC1 and two AcCHUP1 genes induced the aggregation of chloroplasts around the nucleus. Analyses of A. capillus-veneris mutants containing perinuclear-aggregated chloroplasts confirmed that AcKAC1 is required for chloroplast-plasma membrane association. In addition, P. patens lines in which two KAC genes had been knocked out showed an aggregated chloroplast phenotype similar to that of the fern kac1 mutants. These results indicate that chloroplast positioning and movement are mediated through the activities of KAC and CHUP1 proteins, which are conserved in land plants.

  7. Phaseolin expression in tobacco chloroplast reveals an autoregulatory mechanism in heterologous protein translation.

    De Marchis, Francesca; Bellucci, Michele; Pompa, Andrea

    2016-02-01

    Plastid DNA engineering is a well-established research area of plant biotechnology, and plastid transgenes often give high expression levels. However, it is still almost impossible to predict the accumulation rate of heterologous protein in transplastomic plants, and there are many cases of unsuccessful transgene expression. Chloroplasts regulate their proteome at the post-transcriptional level, mainly through translation control. One of the mechanisms to modulate the translation has been described in plant chloroplasts for the chloroplast-encoded subunits of multiprotein complexes, and the autoregulation of the translation initiation of these subunits depends on the availability of their assembly partners [control by epistasy of synthesis (CES)]. In Chlamydomonas reinhardtii, autoregulation of endogenous proteins recruited in the assembly of functional complexes has also been reported. In this study, we revealed a self-regulation mechanism triggered by the accumulation of a soluble recombinant protein, phaseolin, in the stroma of chloroplast-transformed tobacco plants. Immunoblotting experiments showed that phaseolin could avoid this self-regulation mechanism when targeted to the thylakoids in transplastomic plants. To inhibit the thylakoid-targeted phaseolin translation as well, this protein was expressed in the presence of a nuclear version of the phaseolin gene with a transit peptide. Pulse-chase and polysome analysis revealed that phaseolin mRNA translation on plastid ribosomes was repressed due to the accumulation in the stroma of the same soluble polypeptide imported from the cytosol. We suggest that translation autoregulation in chloroplast is not limited to heteromeric protein subunits but also involves at least some of the foreign soluble recombinant proteins, leading to the inhibition of plastome-encoded transgene expression in chloroplast. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Towards an understanding of wheat chloroplasts: a methodical investigation of thylakoid proteome.

    Kamal, Abu Hena Mostafa; Cho, Kun; Komatsu, Setsuko; Uozumi, Nobuyuki; Choi, Jong-Soon; Woo, Sun Hee

    2012-05-01

    We utilized Percoll density gradient centrifugation to isolate and fractionate chloroplasts of Korean winter wheat cultivar cv. Kumgang (Triticum aestivum L.). The resulting protein fractions were separated by one dimensional polyacrylamide gel electrophoresis (1D-PAGE) coupled with LTQ-FTICR mass spectrometry. This enabled us to detect and identify 767 unique proteins. Our findings represent the most comprehensive exploration of a proteome to date. Based on annotation information from the UniProtKB/Swiss-Prot database and our analyses via WoLF PSORT and PSORT, these proteins are localized in the chloroplast (607 proteins), chloroplast stroma (145), thylakoid membrane (342), lumens (163), and integral membranes (166). In all, 67% were confirmed as chloroplast thylakoid proteins. Although nearly complete protein coverage (89% proteins) has been accomplished for the key chloroplast pathways in wheat, such as for photosynthesis, many other proteins are involved in regulating carbon metabolism. The identified proteins were assigned to 103 functional categories according to a classification system developed by the iProClass database and provided through Protein Information Resources. Those functions include electron transport, energy, cellular organization and biogenesis, transport, stress responses, and other metabolic processes. Whereas most of these proteins are associated with known complexes and metabolic pathways, about 13% of the proteins have unknown functions. The chloroplast proteome contains many proteins that are localized to the thylakoids but as yet have no known function. We propose that some of these familiar proteins participate in the photosynthetic pathway. Thus, our new and comprehensive protein profile may provide clues for better understanding that photosynthetic process in wheat.

  9. Structure of cells chloroplasts and mitochondria of cotton leaves following gamma irradiation

    Arslanova, S V [AN Uzbekskoj SSR, Tashkent. Inst. Ehksperimental' noj Biologii Rastenij

    1975-01-01

    The article investigates the structural changes in the plastides and mitochondria of cotton leaf cells after irradiation. Cotton seeds that had been moistened for 24 hours were irradiated by a gamma source with a dose of 10 kR (intensity: 19 R/s.). For the study of the plastides and mitochondria of the leaf cells samples were taken in the cotyledonous leaf and flowering phases of the cotton. The cells of the cotton leaf mesophillum in the standard consists of chloroplast with developed interior structures. Study of the ultrastructure of the cells of the mesophilic tissue of the cotyledonous leaf in irradiated cotton plants showed that the chloroplastide membranes are not damaged. A change in the form of the chloroplasts, an accumulation of starch and plastic substances in the chloroplasts, and a reduction in the number of inter-grain bonds were noted. It was discovered that gamma irradiation produces an excessive build-up of starch in the chloroplasts. The mitochondria are often located close to the plastides. The optical density is typical of the matrix of the mitochondria in non-irradiated plants. After cotton seeds that have sprouted are irradiated with a dose of 10 kR in the cotyledonous leaf phase, part of the mitochondria swells. The matrix becomes more transparent, and the number of chrysts decreases. Part of the mitochondria remains intact. The optical density and internal membranes of the mitochondria remain the same as in the control group. The disturbances of the chloroplast and the mitochondria are also observed in the budding and flowering phases (under conditions of a natural day). It was noted that a shortened day facilitated to some extent a normalization of metabolism, and this produced in turn a normal development of the chloroplasts, leaf mitochondria and ATF generation, which reduces the final biological effect of the radiation.

  10. Complete chloroplast DNA sequence from a Korean endemic genus, Megaleranthis saniculifolia, and its evolutionary implications.

    Kim, Young-Kyu; Park, Chong-wook; Kim, Ki-Joong

    2009-03-31

    The chloroplast DNA sequences of Megaleranthis saniculifolia, an endemic and monotypic endangered plant species, were completed in this study (GenBank FJ597983). The genome is 159,924 bp in length. It harbors a pair of IR regions consisting of 26,608 bp each. The lengths of the LSC and SSC regions are 88,326 bp and 18,382 bp, respectively. The structural organizations, gene and intron contents, gene orders, AT contents, codon usages, and transcription units of the Megaleranthis chloroplast genome are similar to those of typical land plant cp DNAs. However, the detailed features of Megaleranthis chloroplast genomes are substantially different from that of Ranunculus, which belongs to the same family, the Ranunculaceae. First, the Megaleranthis cp DNA was 4,797 bp longer than that of Ranunculus due to an expanded IR region into the SSC region and duplicated sequence elements in several spacer regions of the Megaleranthis cp genome. Second, the chloroplast genomes of Megaleranthis and Ranunculus evidence 5.6% sequence divergence in the coding regions, 8.9% sequence divergence in the intron regions, and 18.7% sequence divergence in the intergenic spacer regions, respectively. In both the coding and noncoding regions, average nucleotide substitution rates differed markedly, depending on the genome position. Our data strongly implicate the positional effects of the evolutionary modes of chloroplast genes. The genes evidencing higher levels of base substitutions also have higher incidences of indel mutations and low Ka/Ks ratios. A total of 54 simple sequence repeat loci were identified from the Megaleranthis cp genome. The existence of rich cp SSR loci in the Megaleranthis cp genome provides a rare opportunity to study the population genetic structures of this endangered species. Our phylogenetic trees based on the two independent markers, the nuclear ITS and chloroplast matK sequences, strongly support the inclusion of the Megaleranthis to the Trollius. Therefore, our

  11. Identification and Characterization of a Chloroplast-Targeted Obg GTPase in Dendrobium officinale.

    Chen, Ji; Deng, Feng; Deng, Mengsheng; Han, Jincheng; Chen, Jianbin; Wang, Li; Yan, Shen; Tong, Kai; Liu, Fan; Tian, Mengliang

    2016-12-01

    Bacterial homologous chloroplast-targeted Obg GTPases (ObgCs) belong to the plant-typical Obg group, which is involved in diverse physiological processes during chloroplast development. However, the evolutionarily conserved function of ObgC in plants remains elusive and requires further investigation. In this study, we identified DoObgC from an epiphytic plant Dendrobium officinale and demonstrated the characteristics of DoObgC. Sequence analysis indicated that DoObgC is highly conserved with other plant ObgCs, which contain the chloroplast transit peptide (cTP), Obg fold, G domain, and OCT regions. The C terminus of DoObgC lacking the chloroplast-targeting cTP region, DoObgC Δ1-160 , showed strong similarity to ObgE and other bacterial Obgs. Overexpression of DoObgC Δ1-160 in Escherichia coli caused slow cell growth and an increased number of elongated cells. This phenotype was consistent with the phenotype of cells overexpressing ObgE. Furthermore, the expression of recombinant DoObgC Δ1-160 enhanced the cell persistence of E. coli to streptomycin. Results of transient expression assays revealed that DoObgC was localized to chloroplasts. Moreover, we demonstrated that DoObgC could rescue the embryotic lethal phenotype of the Arabidopsis obgc-t mutant, suggesting that DoObgC is a functional homolog to Arabidopsis AtObgC in D. officinale. Gene expression profiles showed that DoObgC was expressed in leaf-specific and light-dependent patterns and that DoObgC responded to wounding treatments. Our previous and present studies reveal that ObgC has an evolutionarily conserved role in ribosome biogenesis to adapt chloroplast development to the environment.

  12. Alberta oil sands crudes : upgrading and marketing

    Ashar, M.

    2008-01-01

    Open pit mining and in situ techniques, such as steam stimulation, are used to recover Alberta's bitumen and heavy oil resources, which have higher viscosities than conventional hydrocarbons. The bitumen is typically upgraded to synthetic crude oil (SCO). In the simplest processing scheme, the bitumen is blended with diluent for ease in pipeline transport and then processed at refineries with upgrading facilities. The bitumen is also upgraded to light SCO at world-scale upgraders in Alberta. The SCO is then processed at refineries in downstream markets. The 2 categories of upgrading, notably primary and secondary upgrading, were described in this article along with technology options for both categories. Slurry hydrocracking is regarded as the most interesting emerging residual fuel upgrading technology. It combines special catalyst mixes with the latest slurry reactor designs as well as innovative catalyst capture and recycle schemes to produce very high conversions and potentially superior upgrading economics. The increase in volume and rate of SCO from Alberta provides refiners in the oil sands marketing sector an unprecedented choice of opportunities to improve profitability. Key trends indicate that production will increase substantially from 2008 to 2030. 5 figs

  13. Recovery of uranium from crude uranium tetrafluoride

    Ghosh, S.K.; Bellary, M.P.; Keni, V.S.

    1994-01-01

    An innovative process has been developed for recovery of uranium from crude uranium tetrafluoride cake. The process is based on direct dissolution of uranium tetrafluoride in nitric acid in presence of aluminium hydroxide and use of solvent extraction for removal of fluorides and other bulk impurities to make uranium amenable for refining. It is a simple process requiring minimum process step and has advantage of lesser plant corrosion. This process can be applied for processing of uranium tetrafluoride generated from various sources like uranium by-product during thorium recovery from thorium concentrate, first stage product of uranium recovery from phosphoric acid by OPPA process and off grade uranium tetrafluoride material. The paper describes the details of the process developed and demonstrated on bench and pilot scale and its subsequent modification arising out of bulky solid waste generation. The modified process uses a lower quantity of aluminium hydroxide by allowing a lower dissolution of uranium per cycle and recycles the undissolved material to the next cycle, maintaining the overall recovery at high level. This innovation has reduced the solid waste generated by a factor of four at the cost of a slightly larger dissolution vessel and its increased corrosion rate. (author)

  14. Alberta oil sands crudes : upgrading and marketing

    Ashar, M. [Suncor Energy, Fort McMurray, AB (Canada)

    2008-05-15

    Open pit mining and in situ techniques, such as steam stimulation, are used to recover Alberta's bitumen and heavy oil resources, which have higher viscosities than conventional hydrocarbons. The bitumen is typically upgraded to synthetic crude oil (SCO). In the simplest processing scheme, the bitumen is blended with diluent for ease in pipeline transport and then processed at refineries with upgrading facilities. The bitumen is also upgraded to light SCO at world-scale upgraders in Alberta. The SCO is then processed at refineries in downstream markets. The 2 categories of upgrading, notably primary and secondary upgrading, were described in this article along with technology options for both categories. Slurry hydrocracking is regarded as the most interesting emerging residual fuel upgrading technology. It combines special catalyst mixes with the latest slurry reactor designs as well as innovative catalyst capture and recycle schemes to produce very high conversions and potentially superior upgrading economics. The increase in volume and rate of SCO from Alberta provides refiners in the oil sands marketing sector an unprecedented choice of opportunities to improve profitability. Key trends indicate that production will increase substantially from 2008 to 2030. 5 figs.

  15. Crude oil prices: It's not like '86

    Simmons, M.R.

    1994-01-01

    In 1981, daily crude oil productive capacity exceeded demand by more than 25%, leading to a 4-yr price decline from near $40 per barrel levels, and a sharp drop in 1986 to near $12. But, in 1994, the fundamentals are reversed, worldwide demand is growing, conservation movements are not active, and certain geographic areas, like Asia, are set to tax the system as they modernize. Meanwhile, US and Former Soviet Union production is off, without prospects for near-term turnaround. And there is reason to believe OPEC leaders may not feel compelled to cut their output, when combined small cuts of the magnitude of 5% by the rest of the world's producers could accomplish the same objective of raising oil prices. As with any forecast, only time and hindsight will tell the real story, but 1994 could end up being one of the periodic turning points for what has always been a long-term cyclical industry. This paper summarizes the predictions and causes of predicted price changes

  16. Recovery of uranium from crude uranium tetrafluoride

    Ghosh, S K; Bellary, M P; Keni, V S [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    An innovative process has been developed for recovery of uranium from crude uranium tetrafluoride cake. The process is based on direct dissolution of uranium tetrafluoride in nitric acid in presence of aluminium hydroxide and use of solvent extraction for removal of fluorides and other bulk impurities to make uranium amenable for refining. It is a simple process requiring minimum process step and has advantage of lesser plant corrosion. This process can be applied for processing of uranium tetrafluoride generated from various sources like uranium by-product during thorium recovery from thorium concentrate, first stage product of uranium recovery from phosphoric acid by OPPA process and off grade uranium tetrafluoride material. The paper describes the details of the process developed and demonstrated on bench and pilot scale and its subsequent modification arising out of bulky solid waste generation. The modified process uses a lower quantity of aluminium hydroxide by allowing a lower dissolution of uranium per cycle and recycles the undissolved material to the next cycle, maintaining the overall recovery at high level. This innovation has reduced the solid waste generated by a factor of four at the cost of a slightly larger dissolution vessel and its increased corrosion rate. (author). 4 refs., 1 fig., 3 tabs.

  17. Bioavailability of chemically-dispersed crude oil

    Harris, B.C.; Bonner, J.S.; McDonald, T.J.; Fuller, C.B.; Page, C.A.; Dimitriou-Christidis, P.; Sterling, M.C.; Autenrieth, R.L.

    2002-01-01

    Oil spills can be treated with surfactant compounds to disperse them. This method enables the hydrophobic compounds to overcome their repulsion for water, enter the water phase and be diluted. Once in the water, the biodegradation fraction of the oil biodegrades over time and the residual fraction is deposited over a large area. One major issue which is not fully understood is whether oil compounds pass through the water phase to free floating cells or directly enter oil-attached microbial cells from the oil particle. In this study, crude oil was placed in a swirling flask with Corpus Christi Bay water and was then chemically dispersed with Corexit 9500. The biodegradation was then monitored and assessed. First order rate coefficients were determined based on the disappearance of specific compounds. The rate coefficients for total target PAHs were consistent for all tests. Napthalene, phenanthrene, dibenzothiophene and their alkylated homologs were among the target compounds. The trend was also observed for total target analytes and for total target saturates. The results indicate that the biodegradation rate coefficient was not dependent on the bulk concentration of oil in the water column. It was concluded that biodegradation rates was controlled by partitioning of the compounds between the two phases, and other factors such as particle size distribution and the capability of the microbial culture, temperature and nutrients. 13 refs., 1 tab., 6 figs

  18. Photosynthesis by isolated chloroplasts. VIII. Photosynthetic phosphorylation and the generation of assimilatory power

    Arnon, D I; Whatley, F R; Allen, M B

    1959-01-01

    Photochemical ATP formation by isolated chloroplasts was coupled with a reduction of ferricyanide or TPN. Esterification of two moles of orthophosphate was coupled with the formation of two moles of TPNH/sub 2/ and the evolution of one mole of oxygen. The addition of catalytic amounts of FMN, vitamin K or phenazine methosulfate to the TPN phosphorylating system suppressed TPNH/sub 2/ accumulation as well as oxygen evolution and greatly increased the light-dependent ATP formation. A revised general scheme is presented for photosynthesis by isolated chloroplasts. 35 references, 9 figures, 4 tables.

  19. The DCL gene of tomato is required for chloroplast development and palisade cell morphogenesis in leaves.

    Keddie, J S; Carroll, B; Jones, J D; Gruissem, W

    1996-01-01

    The defective chloroplasts and leaves-mutable (dcl-m) mutation of tomato was identified in a Ds mutagenesis screen. This unstable mutation affects both chloroplast development and palisade cell morphogenesis in leaves. Mutant plants are clonally variegated as a result of somatic excision of Ds and have albino leaves with green sectors. Leaf midribs and stems are light green with sectors of dark green tissue but fruit and petals are wild-type in appearance. Within dark green sectors of dcl-m l...

  20. Noncoding RNA mediated traffic of foreign mRNA into chloroplasts reveals a novel signaling mechanism in plants.

    Gustavo Gómez

    Full Text Available Communication between chloroplasts and the nucleus is one of the milestones of the evolution of plants on earth. Proteins encoded by ancestral chloroplast-endogenous genes were transferred to the nucleus during the endosymbiotic evolution and originated this communication, which is mainly dependent on specific transit-peptides. However, the identification of nuclear-encoded proteins targeted to the chloroplast lacking these canonical signals suggests the existence of an alternative cellular pathway tuning this metabolic crosstalk. Non-coding RNAS (NcRNAs are increasingly recognized as regulators of gene expression as they play roles previously believed to correspond to proteins. Avsunviroidae family viroids are the only noncoding functional RNAs that have been reported to traffic inside the chloroplasts. Elucidating mechanisms used by these pathogens to enter this organelle will unearth novel transport pathways in plant cells. Here we show that a viroid-derived NcRNA acting as a 5'UTR-end mediates the functional import of Green Fluorescent Protein (GFP mRNA into chloroplast. This claim is supported by the observation at confocal microscopy of a selective accumulation of GFP in the chloroplast of the leaves expressing the chimeric vd-5'UTR/GFP and by the detection of the GFP mRNA in chloroplasts isolated from cells expressing this construct. These results support the existence of an alternative signaling mechanism in plants between the host cell and chloroplasts, where an ncRNA functions as a key regulatory molecule to control the accumulation of nuclear-encoded proteins in this organelle. In addition, our findings provide a conceptual framework to develop new biotechnological tools in systems using plant chloroplast as bioreactors. Finally, viroids of the family Avsunviroidae have probably evolved to subvert this signaling mechanism to regulate their differential traffic into the chloroplast of infected cells.

  1. A model for tetrapyrrole synthesis as the primary mechanism for plastid-to-nucleus signaling during chloroplast biogenesis

    Matthew J. Terry

    2013-02-01

    Full Text Available Chloroplast biogenesis involves the co-ordinated expression of the chloroplast and nuclear genomes, requiring information to be sent from the developing chloroplasts to the nucleus. This is achieved through retrograde signaling pathways and can be demonstrated experimentally using the photobleaching herbicide, Norflurazon, which results in chloroplast damage and the reduced expression of many photosynthesis-related, nuclear genes in seedlings. Genetic analysis of this pathway points to a major role for tetrapyrrole synthesis in retrograde signaling, as well as a strong interaction with light-signaling pathways. Currently, the best model to explain the genetic data is that a specific heme pool generated by flux through ferrochelatase-1 functions as a positive signal to promote the expression of genes required for chloroplast development. We propose that this heme-related signal is the primary positive signal during chloroplast biogenesis, and that treatments and mutations affecting chloroplast transcription, RNA editing, translation, or protein import all impact on the synthesis and/or processing of this signal. A positive signal is consistent with the need to provide information on chloroplast status at all times. We further propose that GUN1 normally serves to restrict the production of the heme signal. In addition to a positive signal re-enforcing chloroplast development under normal conditions, aberrant chloroplast development may produce a negative signal due to accumulation of unbound chlorophyll biosynthesis intermediates, such as Mg-porphyrins. Under these conditions a rapid shut-down of tetrapyrrole synthesis is required. We propose that accumulation of these intermediates results in a rapid light-dependent inhibition of nuclear gene expression that is most likely mediated via singlet oxygen generated by photo-excitation of Mg-porphyrins. Thus, the tetrapyrrole pathway may provide both positive and inhibitory signals to control

  2. Efficiency of crude oil markets: Evidences from informational entropy analysis

    Ortiz-Cruz, Alejandro; Rodriguez, Eduardo; Ibarra-Valdez, Carlos; Alvarez-Ramirez, Jose

    2012-01-01

    The role of crude oil as the main energy source for the global economic activity has motivated the discussion about the dynamics and causes of crude oil price changes. An accurate understanding of the issue should provide important guidelines for the design of optimal policies and government budget planning. Using daily data for WTI over the period January 1986–March 2011, we analyze the evolution of the informational complexity and efficiency for the crude oil market through multiscale entropy analysis. The results indicated that the crude oil market is informationally efficient over the scrutinized period except for two periods that correspond to the early 1990s and late 2000s US recessions. Overall, the results showed that deregulation has improved the operation of the market in the sense of making returns less predictable. On the other hand, there is some evidence that the probability of having a severe US economic recession increases as the informational efficiency decreases, which indicates that returns from crude oil markets are less uncertain during economic downturns. - Highlights: ► Entropy concepts are used to characterize crude oil prices. ► An index of market efficiency is introduced. ► Except for periods of economic recession, the crude oil market is informationally efficient.

  3. Crude glycerin in diets for feedlot Nellore cattle

    Eric Haydt Castello Branco van Cleef

    2014-02-01

    Full Text Available Two studies were conducted to evaluate the effects of crude glycerin on feed intake, performance, carcass characteristics, and total digestibility of Nellore bulls. In experiment 1, cattle (n = 30 were fed a control diet without crude glycerin and diets containing 7.5, 15, 22.5, and 30% crude glycerin, for 103 d. Animals were harvested and data of carcass characteristics were collected. In experiment 2, a digestibility trial was performed using indigestible acid detergent fiber (iADF as internal marker, and five rumen-cannulated steers. Both experiments were conducted as a randomized complete block design and data were analyzed using mixed procedures. In experiment 1 no differences were observed among treatments on dry matter intake, and performance variables. Regarding carcass characteristics, no effect was observed, except for carcass fat estimates, which were greater in treatments with crude glycerin. In experiment 2, crude glycerin promoted a decrease in digestibility of fibrous fractions NDF and HEM, and increased digestibility of crude protein by 6%. Although it caused negative effect on digestibility of fibrous fraction of diets, crude glycerin can be a good energy source for Nellore bulls, since no losses are observed on performance and carcass characteristics when animals are fed up to 30% of this by-product.

  4. Crude oil–corn–ethanol – nexus: A contextual approach

    Natanelov, Valeri; McKenzie, Andrew M.; Van Huylenbroeck, Guido

    2013-01-01

    This paper offers a holistic study on the complex relationships between crude oil, corn and ethanol during a turbulent period between 2006 and end of 2011. Through a holistic mapping of the current market situation and a contextual analytical design we show that there exists a strong relationship between crude oil and corn markets on one side, and crude oil and ethanol on the other. However, the price relationship between corn and ethanol was revealed to be less straightforward, and is driven by the US government fuel policy. Furthermore the study indicates that corn markets have became more prone to volatility due to ethanol production, especially when the demand for corn is high and/or the crude oil prices are high enough to create a competitive market for ethanol. - Highlights: • Strong relationship between crude oil–corn and crude oil–ethanol. • Corn–ethanol connected through a by-pass of crude oil markets. • Ethanol market has no direct impact on the price levels of corn. • Corn markets became more prone to volatility due to ethanol production

  5. Boom times : Canada's crude petroleum industry : analysis in brief

    Rowat, M.R.

    2006-01-01

    This document examined the trends in crude oil prices, the production and exports of Canada's crude petroleum industry, and Canada's imports of crude petroleum. As an exporter and importer of crude oil, Canada's petroleum industry is currently experiencing economic prosperity as a result of high oil prices combined with high global demand for oil. This document reviewed industry activity for 2005 and addressed the reasons for the first decline in Canadian crude oil production in 6 years. A quick review of soaring crude oil prices, supply and shortages was also presented. A review of exports revealed that since 1995, the United States has received 99 per cent of Canadian exports. Although production activity is occurring in 7 provinces, the biggest participant is Alberta, followed by Saskatchewan. In 2005, Canada produced 136.4 million cubic metres of crude petroleum, of which two-thirds came from Alberta. Saskatchewan contributed 18 per cent of total Canadian crude oil production, while offshore oil rigs in Newfoundland and Labrador contributed 13 per cent. The vast oil sands resource accounted for 42 per cent of the province's total production. Alberta oil export is piped entirely into the United States. In 2005, even with a slight drop in exports, Canadian oil exporters received $30 billion for their products, up from $25 billion the year before. Canada also supplied nearly 10 per cent of the American crude oil needs. According to the National Energy Board, Canadian refineries are approaching capacity. Canada's 19 refineries, which have a capacity of 320,000 cubic metres per day, operated at 92 per cent of capacity in 2005 to meet the needs of the domestic market. More imported petroleum was refined than Canadian sourced petroleum. In 2005, the gas and oil industry saw historically high profits, taxes paid and investments. 6 refs., 5 figs

  6. Procedures in field systems for collecting and demulsifying crude oils

    Vakhitov, G G; Graifer, V I; Tronov, V P; Zakirov, I G

    1969-01-01

    This microscopic study of crude oil emulsification and demulsification showed that the sooner an emulsion is chemically treated, the less its stability. This finding led to the practice of adding demulsifiers to the crude oil in pipelines. This method of demulsification is now used in Romashkino, Bablinsk, and Elkhovs fields. By this early addition of a chemical, the tendency of the pipeline to form stable, highly viscous emulsions is reduced. This treatment also facilitates separation of water from oil in storage tanks. Repeated tests have shown that pipeline demulsification is a highly effective and economic process. This method reduces crude oil dewatering costs by several hundred percent.

  7. Tweens demulsification effects on heavy crude oil/water emulsion

    Nastaran Hayati Roodbari

    2016-09-01

    Full Text Available The demulsification role of Tweens (nonionic polymers was determined in the separation of water from heavy crude oil emulsion. According to the previous researches, these nonionic polymers, having hydrophilic and lipophilic groups, are appropriate for making oil in water emulsion. In this research their effects in certain concentrations on demulsifying of water in crude oil emulsion were proved. High molecular weight, alkenes’ chains and groups of ketone and ester in these polymers can improve their performance for the demulsification of water in crude oil emulsion. Their efficiencies are improved with electronegative groups such as oxygen. They leave no corrosion effect because they are neutral and do not leave counter ions.

  8. De Novo Assembly of Complete Chloroplast Genomes from Non-model Species Based on a K-mer Frequency-Based Selection of Chloroplast Reads from Total DNA Sequences

    Shairul Izan

    2017-08-01

    Full Text Available Whole Genome Shotgun (WGS sequences of plant species often contain an abundance of reads that are derived from the chloroplast genome. Up to now these reads have generally been identified and assembled into chloroplast genomes based on homology to chloroplasts from related species. This re-sequencing approach may select against structural differences between the genomes especially in non-model species for which no close relatives have been sequenced before. The alternative approach is to de novo assemble the chloroplast genome from total genomic DNA sequences. In this study, we used k-mer frequency tables to identify and extract the chloroplast reads from the WGS reads and assemble these using a highly integrated and automated custom pipeline. Our strategy includes steps aimed at optimizing assemblies and filling gaps which are left due to coverage variation in the WGS dataset. We have successfully de novo assembled three complete chloroplast genomes from plant species with a range of nuclear genome sizes to demonstrate the universality of our approach: Solanum lycopersicum (0.9 Gb, Aegilops tauschii (4 Gb and Paphiopedilum henryanum (25 Gb. We also highlight the need to optimize the choice of k and the amount of data used. This new and cost-effective method for de novo short read assembly will facilitate the study of complete chloroplast genomes with more accurate analyses and inferences, especially in non-model plant genomes.

  9. Persistent negative temperature response of mesophyll conductance in red raspberry (Rubus idaeus L.) leaves under both high and low vapour pressure deficits: a role for abscisic acid?

    Qiu, Changpeng; Ethier, Gilbert; Pepin, Steeve; Dubé, Pascal; Desjardins, Yves; Gosselin, André

    2017-09-01

    The temperature dependence of mesophyll conductance (g m ) was measured in well-watered red raspberry (Rubus idaeus L.) plants acclimated to leaf-to-air vapour pressure deficit (VPDL) daytime differentials of contrasting amplitude, keeping a fixed diurnal leaf temperature (T leaf ) rise from 20 to 35 °C. Contrary to the great majority of g m temperature responses published to date, we found a pronounced reduction of g m with increasing T leaf irrespective of leaf chamber O 2 level and diurnal VPDL regime. Leaf hydraulic conductance was greatly enhanced during the warmer afternoon periods under both low (0.75 to 1.5 kPa) and high (0.75 to 3.5 kPa) diurnal VPDL regimes, unlike stomatal conductance (g s ), which decreased in the afternoon. Consequently, the leaf water status remained largely isohydric throughout the day, and therefore cannot be evoked to explain the diurnal decrease of g m . However, the concerted diurnal reductions of g m and g s were well correlated with increases in leaf abscisic acid (ABA) content, thus suggesting that ABA can induce a significant depression of g m under favourable leaf water status. Our results challenge the view that the temperature dependence of g m can be explained solely from dynamic leaf anatomical adjustments and/or from the known thermodynamic properties of aqueous solutions and lipid membranes.​. © 2017 John Wiley & Sons Ltd.

  10. Regulation of photosynthesis and stomatal and mesophyll conductance under water stress and recovery in olive trees: correlation with gene expression of carbonic anhydrase and aquaporins.

    Perez-Martin, Alfonso; Michelazzo, Chiara; Torres-Ruiz, Jose M; Flexas, Jaume; Fernández, José E; Sebastiani, Luca; Diaz-Espejo, Antonio

    2014-07-01

    The hypothesis that aquaporins and carbonic anhydrase (CA) are involved in the regulation of stomatal (g s) and mesophyll (g m) conductance to CO2 was tested in a short-term water-stress and recovery experiment in 5-year-old olive plants (Olea europaea) growing outdoors. The evolution of leaf gas exchange, chlorophyll fluorescence, and plant water status, and a quantitative analysis of photosynthesis limitations, were followed during water stress and recovery. These variables were correlated with gene expression of the aquaporins OePIP1.1 and OePIP2.1, and stromal CA. At mild stress and at the beginning of the recovery period, stomatal limitations prevailed, while the decline in g m accounted for up to 60% of photosynthesis limitations under severe water stress. However, g m was restored to control values shortly after rewatering, facilitating the recovery of the photosynthetic rate. CA was downregulated during water stress and upregulated after recovery. The use of structural equation modelling allowed us to conclude that both OePIP1.1 and OePIP2.1 expression could explain most of the variations observed for g s and g m. CA expression also had a small but significant effect on g m in olive under water-stress conditions. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. Mesophyll conductance decreases in the wild type but not in an ABA-deficient mutant (aba1) of Nicotiana plumbaginifolia under drought conditions.

    Mizokami, Yusuke; Noguchi, Ko; Kojima, Mikiko; Sakakibara, Hitoshi; Terashima, Ichiro

    2015-03-01

    Under drought conditions, leaf photosynthesis is limited by the supply of CO2 . Drought induces production of abscisic acid (ABA), and ABA decreases stomatal conductance (gs ). Previous papers reported that the drought stress also causes the decrease in mesophyll conductance (gm ). However, the relationships between ABA content and gm are unclear. We investigated the responses of gm to the leaf ABA content [(ABA)L ] using an ABA-deficient mutant, aba1, and the wild type (WT) of Nicotiana plumbaginifolia. We also measured leaf water potential (ΨL ) because leaf hydraulics may be related to gm . Under drought conditions, gm decreased with the increase in (ABA)L in WT, whereas both (ABA)L and gm were unchanged by the drought treatment in aba1. Exogenously applied ABA decreased gm in both WT and aba1 in a dose-dependent manner. ΨL in WT was decreased by the drought treatment to -0.7 MPa, whereas ΨL in aba1 was around -0.8 MPa even under the well-watered conditions and unchanged by the drought treatment. From these results, we conclude that the increase in (ABA)L is crucial for the decrease in gm under drought conditions. We discuss possible relationships between the decrease in gm and changes in the leaf hydraulics. © 2014 John Wiley & Sons Ltd.

  12. Carcass characteristics of feedlot lambs fed crude glycerin contaminated with high concentrations of crude fat.

    Lage, J F; Paulino, P V R; Pereira, L G R; Duarte, M S; Valadares Filho, S C; Oliveira, A S; Souza, N K P; Lima, J C M

    2014-01-01

    Thirty non-castrated male lambs with 20±2.3 kg average body weight (BW) were randomly assigned to five treatments consisted of different dietary concentrations of crude glycerin (CG; 0, 3, 6, 9 and 12% on DM basis) to evaluate the effects on performance, carcass and meat quality traits. A quadratic effect was observed for performance (P=0.04), final BW (P0.05) on carcass pH neither on shear-force, cooking loss and ether extract content in longissimus. The inclusion of CG tended to reduce the Zn content in meat (P=0.09). The data suggests that CG (36.2% of glycerol and 46.5% of crude fat) may be used in diets of finishing lambs with concentrations up to 3% without negative effects on performance and main carcass traits. Moreover, inclusion of CG seems to not affect quality and safety of meat for human consumption. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Electron cryomicroscopy of two-dimensional crystals of the H+-ATPase from chloroplasts

    Böttcher, Bettina; Gräber, Peter; Boekema, Egbert J.; Lücken, Uwe

    1995-01-01

    The H+-ATPase from spinach chloroplasts was isolated and purified. Two-dimensional crystals were obtained from the protein/lipid/detergent micelles by treatment with phospholipase and simultaneous removal of detergent and fatty acids by Biobeads. The resulting two-dimensionally ordered arrays were

  14. ELECTRON CRYOMICROSCOPY OF 2-DIMENSIONAL CRYSTALS OF THE H+-ATPASE FROM CHLOROPLASTS

    BOTTCHER, B; GRABER, P; BOEKEMA, EJ; LUCKEN, U

    1995-01-01

    The H+-ATPase from spinach chloroplasts was isolated and purified, Two-dimensional crystals were obtained from the protein/lipid/detergent micelles by treatment with phospholipase and simultaneous removal of detergent and fatty acids by Biobeads. The resulting two-dimensionally ordered arrays were

  15. Electrochromic effects in relation to energy transduction and energy coupling in chloroplast membranes

    Peters, R.L.A.

    1986-01-01

    A study was made on the kinetics of the flash-induced P515 electrochromic bandshift signal in spinach leaves and isolated chloroplasts. It was found that part of the signal (i.e. the slow component, also called reaction 2), normally present in dark-adapted membranes is absent from the signal under

  16. Diversity of chloroplast genome among local clones of cocoa (Theobroma cacao, L.) from Central Sulawesi

    Suwastika, I. Nengah; Pakawaru, Nurul Aisyah; Rifka, Rahmansyah, Muslimin, Ishizaki, Yoko; Cruz, André Freire; Basri, Zainuddin; Shiina, Takashi

    2017-02-01

    Chloroplast genomes typically range in size from 120 to 170 kilo base pairs (kb), which relatively conserved among plant species. Recent evaluation on several species, certain unique regions showed high variability which can be utilized in the phylogenetic analysis. Many fragments of coding regions, introns, and intergenic spacers, such as atpB-rbcL, ndhF, rbcL, rpl16, trnH-psbA, trnL-F, trnS-G, etc., have been used for phylogenetic reconstructions at various taxonomic levels. Based on that status, we would like to analysis the diversity of chloroplast genome within species of local cacao (Theobroma cacao L.) from Central Sulawesi. Our recent data showed, there were more than 20 clones from local farming in Central Sulawesi, and it can be detected based on phenotypic and nuclear-genome-based characterization (RAPD- Random Amplified Polymorphic DNA and SSR- Simple Sequences Repeat) markers. In developing DNA marker for this local cacao, here we also included analysis based on the variation of chloroplast genome. At least several regions such as rpl32-TurnL, it can be considered as chloroplast markers on our local clone of cocoa. Furthermore, we could develop phylogenetic analysis in between clones of cocoa.

  17. A set of 100 chloroplast DNA primer pairs to study population genetics and phylogeny in monocotylenons

    Scarcelli, Nora; Bernaud, Adeline; Eiserhardt, Wolf L.

    2011-01-01

    Chloroplast DNA sequences are of great interest for population genetics and phylogenetic studies. However, only a small set of markers are commonly used. Most of them have been designed for amplification in a large range of Angiosperms and are located in the Large Single Copy (LSC). Here we...... anticipate that it will also be useful for phylogeny and bar-coding studies....

  18. Sequencing of chloroplast genome using whole cellular DNA and Solexa sequencing technology

    Jian eWu

    2012-11-01

    Full Text Available Sequencing of the chloroplast genome using traditional sequencing methods has been difficult because of its size (>120 kb and the complicated procedures required to prepare templates. To explore the feasibility of sequencing the chloroplast genome using DNA extracted from whole cells and Solexa sequencing technology, we sequenced whole cellular DNA isolated from leaves of three Brassica rapa accessions with one lane per accession. In total, 246 Mb, 362Mb, 361 Mb sequence data were generated for the three accessions Chiifu-401-42, Z16 and FT, respectively. Microreads were assembled by reference-guided assembly using the cpDNA sequences of B. rapa, Arabidopsis thaliana, and Nicotiana tabacum. We achieved coverage of more than 99.96% of the cp genome in the three tested accessions using the B. rapa sequence as the reference. When A. thaliana or N. tabacum sequences were used as references, 99.7–99.8% or 95.5–99.7% of the B. rapa chloroplast genome was covered, respectively. These results demonstrated that sequencing of whole cellular DNA isolated from young leaves using the Illumina Genome Analyzer is an efficient method for high-throughput sequencing of chloroplast genome.

  19. Nano-scale characterization of the dynamics of the chloroplast Toc translocon.

    Reddick, L Evan; Chotewutmontri, Prakitchai; Crenshaw, Will; Dave, Ashita; Vaughn, Michael; Bruce, Barry D

    2008-01-01

    Translocons are macromolecular nano-scale machines that facilitate the selective translocation of proteins across membranes. Although common in function, different translocons have evolved diverse molecular mechanisms for protein translocation. Subcellular organelles of endosymbiotic origin such as the chloroplast and mitochondria had to evolve/acquire translocons capable of importing proteins whose genes were transferred to the host genome. These gene products are expressed on cytosolic ribosomes as precursor proteins and targeted back to the organelle by an N-terminal extension called the transit peptide or presequence. In chloroplasts the transit peptide is specifically recognized by the Translocon of the Outer Chloroplast membrane (Toc) which is composed of receptor GTPases that potentially function as gate-like switches, where GTP binding and hydrolysis somehow facilitate preprotein binding and translocation. Compared to other translocons, the dynamics of the Toc translocon are probably more complex and certainly less understood. We have developed biochemical/biophysical, imaging, and computational techniques to probe the dynamics of the Toc translocon at the nanoscale. In this chapter we provide detailed protocols for kinetic and binding analysis of precursor interactions in organeller, measurement of the activity and nucleotide binding of the Toc GTPases, native electrophoretic analysis of the assembly/organization of the Toc complex, visualization of the distribution and mobility of Toc apparatus on the surface of chloroplasts, and conclude with the identification and molecular modeling Toc75 POTRA domains. With these new methodologies we discuss future directions of the field.

  20. Regulation of photosynthetic electron flow in isolated chloroplasts by bicarbonate, formate and herbicides

    Snel, J.F.H.

    1985-01-01

    This thesis describes some efforts that were made to gain a better understanding of the processes involved in the regulation of photosynthetic electron flow by bicarbonate, formate and herbicides in chloroplasts. In the past decade a large amount of research has been devoted to get insight into the

  1. Increasing phylogenetic resolution at low taxonomic levels using massively parallel sequencing of chloroplast genomes

    Matthew Parks; Richard Cronn; Aaron Liston

    2009-01-01

    We reconstruct the infrageneric phylogeny of Pinus from 37 nearly-complete chloroplast genomes (average 109 kilobases each of an approximately 120 kilobase genome) generated using multiplexed massively parallel sequencing. We found that 30/33 ingroup nodes resolved wlth > 95-percent bootstrap support; this is a substantial improvement relative...

  2. A tiling microarray for global analysis of chloroplast genome expression in cucumber and other plants

    Pląder Wojciech

    2011-09-01

    Full Text Available Abstract Plastids are small organelles equipped with their own genomes (plastomes. Although these organelles are involved in numerous plant metabolic pathways, current knowledge about the transcriptional activity of plastomes is limited. To solve this problem, we constructed a plastid tiling microarray (PlasTi-microarray consisting of 1629 oligonucleotide probes. The oligonucleotides were designed based on the cucumber chloroplast genomic sequence and targeted both strands of the plastome in a non-contiguous arrangement. Up to 4 specific probes were designed for each gene/exon, and the intergenic regions were covered regularly, with 70-nt intervals. We also developed a protocol for direct chemical labeling and hybridization of as little as 2 micrograms of chloroplast RNA. We used this protocol for profiling the expression of the cucumber chloroplast plastome on the PlasTi-microarray. Owing to the high sequence similarity of plant plastomes, the newly constructed microarray can be used to study plants other than cucumber. Comparative hybridization of chloroplast transcriptomes from cucumber, Arabidopsis, tomato and spinach showed that the PlasTi-microarray is highly versatile.

  3. BEL1-LIKE HOMEODOMAIN 11 regulated chloroplast development and chlorophyll synthesis in tomato fruit

    Chloroplast development and chlorophyll content and metabolism in unripe tomato contribute to the growth and development of the fruit, and also the ripe fruit quality, but the mechanism is poorly understood. In this work, seven homeobox-containing transcription factors (TFs) with specific ripening-a...

  4. Chloroplast evolution in the Pinus montezumae complex: a coalescent approach to hybridization.

    Matos, J A; Schaal, B A

    2000-08-01

    This study addresses the evolutionary history of the chloroplast genomes of two closely related pine species, Pinus hartwegii Lindl. and P. montezumae Lamb (subsect. Ponderosae) using coalescent theory and some of the statistical tools that have been developed from it during the past two decades. Pinus hartwegii and P. montezumae are closely related species in the P. montezumae complex (subsect. Ponderosae) of Mexico and Central America. Pinus hartwegii is a high elevation species, whereas P. montezumae occurs at lower elevations. The two species occur on many of the same mountains throughout Mexico. A total of 350 individuals of P. hartwegii and P. montezumae were collected from Nevado de Colima (Jalisco), Cerro Potosí (Nuevo León), Iztaccihuatl/Popocatepetl (México), and Nevado de Toluca (México). The chloroplast genome of P. hartwegii and P. montezumae was mapped using eight restriction enzymes. Fifty-one different haplotypes were characterized; 38 of 160 restriction sites were polymorphic. Clades of most parsimoniously related chloroplast haplotypes are geographically localized and do not overlap in distribution, and the geographically localized clades of haplotypes include both P. hartwegii and P. montezumae. Some haplotypes in the clades occur in only one of the two species, whereas other haplotypes occur in both species. These data strongly suggest ancient and/or ongoing hybridization between P. hartwegii and P. montezumae and a shared chloroplast genome history within geographic regions of Mexico.

  5. Rangewide Genetic Variation in Coast Redwood Populations at a Chloroplast Microsatellite Locus

    Chris Brinegar

    2012-01-01

    Old growth and second growth populations of coast redwood (Sequoia sempervirens) were sampled at 10 locations throughout its range and analyzed at a highly variable chloroplast microsatellite locus. Very low FST values indicated that there was no significant genetic differentiation between adjacent old growth and second growth populations at each location. Genetic...

  6. Inner structure of intact chloroplasts observed by a low temperature laser scanning microscope

    Vácha, František; Vácha, M.; Bumba, L.; Hashizume, K.; Tani, T.

    2000-01-01

    Roč. 38, - (2000), s. 493-496 ISSN 0300-3604 R&D Projects: GA MŠk ME 156; GA MŠk VS96085 Keywords : chloroplasts * physiology * scanning microscopy Subject RIV: EE - Microbiology, Virology Impact factor: 0.482, year: 2000

  7. Photosynthesis by isolated chloroplasts. IV. General concept and comparison of three photochemical reactions

    Arnon, D I; Allen, M B; Whatley, F R

    1956-01-01

    Procedures are described for the preparation of chloroplasts capable of carrying out three photochemical reactions, each representing an increasingly complex phase of photosynthesis: photolysis of water (Hill reaction), esterification of inorganic phosphate into adenosine triphosphate (photosynthetic phosphorylation) and the reduction of carbon dioxide to the level of carbohydrates with a simultaneous evolution of oxygen. The three photochemical reactions were separable by variations in the technique for preparation of chloroplasts and by differential inhibition by several reagents. Inhibition of a more complex phase of photosynthesis does not affect the simpler one which precedes it and, conversely, the inhibition of a simpler phase of photosynthesis is paralleled by an inhibition of the more complex phase which follows. Reversible inhibition of CO/sub 2/ fixation and photosynthetic phosphorylation, but not of photolysis, by sulfhydryl group inhibitors suggests that sulfhydryl compounds (enzymes, cofactors, or both) are involved in phosphorylation and CO/sub 2/ fixation, but not in the primary conversion of light into chemical energy as measured by the Hill reaction. Evidence is presented in support of the conclusion that the synthesis of ATP by green cells occurs at two distinct sites: anaerobically in chloroplasts by photosynthetic phosphorylation, and acrobically in smaller cytoplasmic particles, presumably mitochondria, by oxidative phosphorylation independent of light. A general scheme of photosynthesis by chloroplasts, consistent with these findings, is presented. 44 references, 8 figures, 4 tables.

  8. Differences in thermal acclimation of chloroplast functioning in two ecotypes of Valonia utricularis (Chlorophyta)

    Eggert, A.; van Hasselt, P.R; Breeman, Arno

    Chloroplast functioning in two temperature ecotypes of the tropical to warm-temperate green macrophyte Valonia ultricularis was monitored by measuring chlorophyll a fluorescence parameters. One ecotype from the Mediterranean Sea is, with respect to growth and survival, more cold-adapted and

  9. Complete Chloroplast Genomes of Papaver rhoeas and Papaver orientale: Molecular Structures, Comparative Analysis, and Phylogenetic Analysis

    Jianguo Zhou

    2018-02-01

    Full Text Available Papaver rhoeas L. and P. orientale L., which belong to the family Papaveraceae, are used as ornamental and medicinal plants. The chloroplast genome has been used for molecular markers, evolutionary biology, and barcoding identification. In this study, the complete chloroplast genome sequences of P. rhoeas and P. orientale are reported. Results show that the complete chloroplast genomes of P. rhoeas and P. orientale have typical quadripartite structures, which are comprised of circular 152,905 and 152,799-bp-long molecules, respectively. A total of 130 genes were identified in each genome, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Sequence divergence analysis of four species from Papaveraceae indicated that the most divergent regions are found in the non-coding spacers with minimal differences among three Papaver species. These differences include the ycf1 gene and intergenic regions, such as rpoB-trnC, trnD-trnT, petA-psbJ, psbE-petL, and ccsA-ndhD. These regions are hypervariable regions, which can be used as specific DNA barcodes. This finding suggested that the chloroplast genome could be used as a powerful tool to resolve the phylogenetic positions and relationships of Papaveraceae. These results offer valuable information for future research in the identification of Papaver species and will benefit further investigations of these species.

  10. The ultrastructure of chloroplasts in variegata irregulare mutants of garden petunias (Petunia hybrida hort. superbissima

    Stanisław Muszyński

    2015-01-01

    Full Text Available The ultrastructure of mutated chloroplasts in tetraploid garden petunias (Petunia hybrida hort. superbissima was analyzed by electron microscopy. The formation of grana structure is inhibited after secondary thylacoids start forming. Rapid dezintegration of the structure is observed. It is suggested that a substance responsible for photostabilization of grana structure is lacking.

  11. Chloroplast DNA variation of oaks in western Central Europe and genetic consequences of human influences

    König, A.O.; Ziegenhagen, B.; Dam, van B.C.; Csaikl, U.M.; Coart, E.; Degen, B.; Burg, K.; Vries, de S.M.G.; Petit, R.J.

    2002-01-01

    Oak chloroplast DNA (cpDNA) variation was studied in a grid-based inventory in western Central Europe, including Belgium, The Netherlands, Luxembourg, Germany, the Czech Republic, and the northern parts of Upper and Lower Austria. A total of 2155 trees representing 426 populations of Quercus robur

  12. Insights into phylogeny, sex function and age of Fragaria based on whole chloroplast genome sequencing

    Wambui Njunguna; Aaron Liston; Richard Cronn; Tia-Lynn Ashman; Nahla Bassil

    2013-01-01

    The cultivated strawberry is one of the youngest domesticated plants, developed in France in the 1700s from chance hybridization between two western hemisphere octoploid species. However, little is known about the evolution of the species that gave rise to this important fruit crop. Phylogenetic analysis of chloroplast genome sequences of 21 Fragaria...

  13. The relationship between SARA fractions and crude oil stability

    Siavash Ashoori

    2017-03-01

    Full Text Available Asphaltene precipitation and deposition are drastic issues in the petroleum industry. Monitoring the asphaltene stability in crude oil is still a serious problem and has been subject of many studies. To investigate crude oil stability by saturate, aromatic, resin and asphaltene (SARA analysis seven types of crudes with different components were used. The applied methods for SARA quantification are IP-143 and ASTM D893-69 and the colloidal instability index (CII is computed from the SARA values as well. In comparison between CII results, the values of oil compositions demonstrated that the stability of asphaltenes in crude oils is a phenomenon that is related to all these components and it cannot be associated only with one of them, individually.

  14. How is the international price of a particular crude determined?

    Hagen, Ronald

    1994-01-01

    If crude oil or oil products are not the final item of consumption, then oil is not bought or sold on any basis other than its contribution to the final product. The markets of oil products are thus 'derived' from more basic demands, and prices are determined by what they contribute to the costs of producing final products or commodities. Similarly, the value of a crude oil is derived from the value of the petroleum products it yields. This paper attempts to show how differences in crude oil prices seem to occur. The results should be of interest to producers of crude oil, since they will demonstrate how the marketability of their products might vary. (author)

  15. Dynamic Relationship between Crude Oil Price, Exchange Rate and ...

    DrNneka

    Second, since Hamilton (1983) documented the impact of crude oil price volatility .... Hariri,2013) sourced from the U.S. Energy Information Administration (EIA). .... is explained by identifying the relative importance of a variable in generating.

  16. Evaluation of Crude Oil Biodegradation Efficiency and Peroxidase ...

    ADOWIE PERE

    Increase in biomass enhanced degradation efficiency above 80 % after 10 days for all concentration of crude oil studied. Peroxidase ... compounds by various bacteria and fungi (Gianfreda et al, 1999) ... into a clean plastic container. Microbial.

  17. Investigating Asphaltenes Composition in Crude Oil Samples using ...

    MBI

    2015-12-22

    Dec 22, 2015 ... composition of asphaltenes by Iatroscan TLC-FID method was compared with the weight% of asphaltenes precipitated. ... SARA in the crude oil samples were determined in this work ..... Fractionation and characterization of.

  18. Toxity of Gedunin, Piperine and Crude Extracts of their Natural ...

    Toxity of Gedunin, Piperine and Crude Extracts of their Natural Products on Growth and Development of Ostrinia Nubilalis Hbner (Lepidoptera: Pyrarlidae). F K Ewete, J T Arnason, T Durst, S Mackinnon ...

  19. Some effects of simultaneous administration of crude aqueous ...

    The result shows that the crude aqueous extract of mango levels has adverse effect on the morphology and some hepatic enzyme ... Keywords: Mango leaves, Tetracycline, Liver histology, Liver enzymes (AST and ALT) ... HOW TO USE AJOL.

  20. Enhancement of Crude Oil Polluted Soil by Applying Single and ...

    ADOWIE PERE

    bioline.org.br/ja ... 5 kg of soil each was polluted with 200 ml of crude oil ... organic matter, phosphate, nitrate, total hydrocarbon content, potassium and microbial population were analyzed before ... arise mainly from the processing and distribution of.

  1. Microwave-gamma ray water in crude monitor

    Paap, H.J.

    1984-01-01

    A microwave-gamma ray water-in-crude monitoring system measures the percent quantity of fresh water or salt water in crude oil flowing in a pipe line. The system includes a measuring cell arranged with the pipe line so that the crude oil flows through the measuring cell. A microwave transmitter subsystem and a gamma ray source are arranged with the measuring cell so that microwave energy and gamma rays are transmitted through the measuring cell. A microwave receiving subsystem and a gamma ray detector provide signals corresponding to received microwave energy and to the received gamma rays, respectively. Apparatus connected to the microwave receiver and to the gamma ray detector provides an indication of the percentage of water in the crude oil

  2. The crude petroleum and natural gas industry, 1995

    1996-01-01

    A compilation of data regarding the crude petroleum and natural gas industry was presented. This industry includes establishments engaged in exploration for, or production of petroleum or natural gas from wells or tar sands. Data presented in this publication include: the supply and disposition of crude oil and natural gas, operating and capital expenditures of approximately 500 companies of the oil and natural gas industry, drilling completions, and crude oil and natural gas reserves. Data about the oil sands industry is reported in another volume. Much of the data was obtained from the Canadian Association of Petroleum Producers. Overall, in 1995 Canadian natural gas production rose 6.7%; exports of crude oil rose 7.7%. 8 tabs., 2 figs

  3. crude methanolic extracts of ageratum conyzoides and cutaneous ...

    Anatomy

    wound in the experimental group was dressed with crude methanolic extract of Ageratum conyzoides at a five daily interval while the animals in the control group were dressed with normal saline at ... in Africa (Almagboul et al, 1985), Asia, and.

  4. Some Effects Of Simultaneous Administration Of Crude Aqueous

    2017-06-12

    Jun 12, 2017 ... This study was designed to determine the simultaneous effect of Mangifera indica crude aqueous extract and the ... reproductive system (Farombi et al, 2008). Liver is the ... leaves were obtained, then air-dried for six weeks.

  5. An isolated bacterial consortium for crude oil biodegradation

    GREGORY

    2011-12-16

    Dec 16, 2011 ... African Journal of Biotechnology Vol. 10(81), pp. ... The removal of crude oil by bioremediation was achieved in less time as compared to natural attenuation ... Environmental pollution, especially with hydrocarbons is a major ...

  6. The crude petroleum and natural gas industry : 1996

    1997-01-01

    Statistics regarding Canada's crude oil and natural gas industry for 1996 were presented. Data presentation was in tabular form, the topics being exploration and development, synthetic crude oil reserves, crude oil production and movements by source, natural gas production, drilling completions, net cash expenditures of the petroleum industry, and total sales of natural gas by province. Some of the noteworthy highlights for 1996 were: (1) 14,600 new wells were drilled, the highest number ever recorded, (2) capital investment was over $13 billion, (3) 148 companies were involved in mergers and acquisitions, (4) value of marketable production of oil, natural gas and natural gas by-products topped $30 billion, (5) Empress pipelines began operations of the first new major oil pipeline from Western Canada in 45 years, (6) the Hibernia offshore crude oil facility was completed, (7) Sable Island offshore energy projects applications were filed, and (8) the development of the Terra Nova, Whitehorse and Hebron fields was announced. 8 tabs

  7. Experimental study on yield behavior of Daqing crude oil

    Hou, Lei [China University of Petroleum, College of Mechanical and Transportation Engineering, Beijing (China)

    2012-07-15

    The yield behavior of Daqing crude oil was studied by means of multi-mode controlled-stress tests with a high-precision stress controlled rheometer. Two experiments of creep and constant stress loading rate were performed. The yield stress of gelled crude oil was dependent on the test conditions such as the stress loading time and the stress loading rate, but the yield strain did not change with test conditions. The yield strain did exist objectively and it can be used as the criterion for the yielding of the structure of gelled crude oil. The yield strain of gelled oil was studied through experiments of creep, constant stress loading rate, oscillatory shear stress increase, and constant shear rate. The yield strain of gelled crude oil decreased with the increasing gel strength. The experiment of constant speed increase of stress showed the strain softening phenomena for low gel strength oil. (orig.)

  8. Uptake of crude petroleum hydrocarbons by mudflat bacteria ...

    SERVER

    2007-08-06

    Aug 6, 2007 ... bacteria exposed to nitrogenous fertilizer plant ... accompanied by a rapid decline in the level of crude petroleum in the amended .... conductivity, turbidity, salinity, dissolved oxygen (fresh sample only) ... Nutrient uptake was.

  9. Mineral, vitamin C and crude protein contents in kale (Brassica ...

    ajl yemi

    2011-10-27

    Oct 27, 2011 ... Key words: Kale (Brassica oleracea var. acephala), harvesting stage, vitamin C, crude protein, mineral content. .... L-ascorbic acid (or vitamin C) in plant tissues. .... Cooking methods of Brassica rapa affect the preservation of.

  10. Influence of feeding varying crude protein and digestible energy ...

    Influence of feeding varying crude protein and digestible energy levels on the development of individual muscles, rate of lean and fat deposition in pigs reared from 9 to 60kg liveweight in a humid tropical environment.

  11. High temperature corrosion control and monitoring for processing acidic crudes

    Cross, C. [Betz/GE Water and Process Technologies, Woodlands, TX (United States)

    2009-07-01

    The challenge of processing heavy crudes and bitumen in a reliable and economical way was discussed. Many refiners use a conservative approach regarding the rate at which they use discounted crudes or depend upon capital-intensive upgrades to equipment. New strategies based on data-driven decisions are needed in order to obtain the greatest benefit from heavy feedstock. The feasibility of successfully processing more challenging feed can be estimated more accurately by better understanding the interactions between a particular feed and a particular crude unit. This presentation reviewed newly developed techniques that refiners can use to determine the feeds corrosion potential and the probability for this potential to manifest itself in a given crude unit. tabs., figs.

  12. The complete chloroplast DNA sequence of the green alga Oltmannsiellopsis viridis reveals a distinctive quadripartite architecture in the chloroplast genome of early diverging ulvophytes

    Lemieux Claude

    2006-02-01

    Full Text Available Abstract Background The phylum Chlorophyta contains the majority of the green algae and is divided into four classes. The basal position of the Prasinophyceae has been well documented, but the divergence order of the Ulvophyceae, Trebouxiophyceae and Chlorophyceae is currently debated. The four complete chloroplast DNA (cpDNA sequences presently available for representatives of these classes have revealed extensive variability in overall structure, gene content, intron composition and gene order. The chloroplast genome of Pseudendoclonium (Ulvophyceae, in particular, is characterized by an atypical quadripartite architecture that deviates from the ancestral type by a large inverted repeat (IR featuring an inverted rRNA operon and a small single-copy (SSC region containing 14 genes normally found in the large single-copy (LSC region. To gain insights into the nature of the events that led to the reorganization of the chloroplast genome in the Ulvophyceae, we have determined the complete cpDNA sequence of Oltmannsiellopsis viridis, a representative of a distinct, early diverging lineage. Results The 151,933 bp IR-containing genome of Oltmannsiellopsis differs considerably from Pseudendoclonium and other chlorophyte cpDNAs in intron content and gene order, but shares close similarities with its ulvophyte homologue at the levels of quadripartite architecture, gene content and gene density. Oltmannsiellopsis cpDNA encodes 105 genes, contains five group I introns, and features many short dispersed repeats. As in Pseudendoclonium cpDNA, the rRNA genes in the IR are transcribed toward the single copy region featuring the genes typically found in the ancestral LSC region, and the opposite single copy region harbours genes characteristic of both the ancestral SSC and LSC regions. The 52 genes that were transferred from the ancestral LSC to SSC region include 12 of those observed in Pseudendoclonium cpDNA. Surprisingly, the overall gene organization of

  13. Photosynthesis-dependent H2O2 transfer from chloroplasts to nuclei provides a high-light signalling mechanism.

    Exposito-Rodriguez, Marino; Laissue, Pierre Philippe; Yvon-Durocher, Gabriel; Smirnoff, Nicholas; Mullineaux, Philip M

    2017-06-29

    Chloroplasts communicate information by signalling to nuclei during acclimation to fluctuating light. Several potential operating signals originating from chloroplasts have been proposed, but none have been shown to move to nuclei to modulate gene expression. One proposed signal is hydrogen peroxide (H 2 O 2 ) produced by chloroplasts in a light-dependent manner. Using HyPer2, a genetically encoded fluorescent H 2 O 2 sensor, we show that in photosynthetic Nicotiana benthamiana epidermal cells, exposure to high light increases H 2 O 2 production in chloroplast stroma, cytosol and nuclei. Critically, over-expression of stromal ascorbate peroxidase (H 2 O 2 scavenger) or treatment with DCMU (photosynthesis inhibitor) attenuates nuclear H 2 O 2 accumulation and high light-responsive gene expression. Cytosolic ascorbate peroxidase over-expression has little effect on nuclear H 2 O 2 accumulation and high light-responsive gene expression. This is because the H 2 O 2 derives from a sub-population of chloroplasts closely associated with nuclei. Therefore, direct H 2 O 2 transfer from chloroplasts to nuclei, avoiding the cytosol, enables photosynthetic control over gene expression.Multiple plastid-derived signals have been proposed but not shown to move to the nucleus to promote plant acclimation to fluctuating light. Here the authors use a fluorescent hydrogen peroxide sensor to provide evidence that H 2 O 2 is transferred directly from chloroplasts to nuclei to control nuclear gene expression.

  14. Origins of the amphiploid species Brassica napus L. investigated by chloroplast and nuclear molecular markers

    Allender Charlotte J

    2010-03-01

    Full Text Available Abstract Background The amphiploid species Brassica napus (oilseed rape, Canola is a globally important oil crop yielding food, biofuels and industrial compounds such as lubricants and surfactants. Identification of the likely ancestors of each of the two genomes (designated A and C found in B. napus would facilitate incorporation of novel alleles from the wider Brassica genepool in oilseed rape crop genetic improvement programmes. Knowledge of the closest extant relatives of the genotypes involved in the initial formation of B. napus would also allow further investigation of the genetic factors required for the formation of a stable amphiploid and permit the more efficient creation of fully fertile re-synthesised B. napus. We have used a combination of chloroplast and nuclear genetic markers to investigate the closest extant relatives of the original maternal progenitors of B. napus. This was based on a comprehensive sampling of the relevant genepools, including 83 accessions of A genome B. rapa L. (both wild and cultivated types, 94 accessions of B. napus and 181 accessions of C genome wild and cultivated B. oleracea L. and related species. Results Three chloroplast haplotypes occurred in B. napus. The most prevalent haplotype (found in 79% of accessions was not present within the C genome accessions but was found at low frequencies in B. rapa. Chloroplast haplotypes characteristic of B. napus were found in a small number of wild and weedy B. rapa populations, and also in two accessions of cultivated B. rapa 'brocoletto'. Whilst introgression of the B. napus chloroplast type in the wild and weedy B. rapa populations has been proposed by other studies, the presence of this haplotype within the two brocoletto accessions is unexplained. Conclusions The distribution of chloroplast haplotypes eliminate any of the C genome species as being the maternal ancestor of the majority of the B. napus accessions. The presence of multiple chloroplast

  15. Isolation and identification of an ester from a crude oil

    Phillips, H.F.; Breger, I.A.

    1958-01-01

    A dioctylphthalate has been isolated from a crude oil by means of adsorption column chromatography. The ester was identified by means of elemental analysis, refractive index, and its infra-red absorption spectrum. Saponification of the isolate and examination of the resultant alcohol by means of infrared absorption spectra led to the conclusion that the ester is a branched chain dioctylphthalate. This is the first reported occurrence of an ester in crude petroleum. ?? 1958.

  16. Feasibility Process for Remediation of the Crude Oil Contaminated Soil

    Keum, H.; Choi, H.; Heo, H.; Lee, S.; Kang, G.

    2015-12-01

    More than 600 oil wells were destroyed in Kuwait by Iraqi in 1991. During the war, over 300 oil lakes with depth of up to 2m at more than 500 different locations which has been over 49km2. Therefore, approximately 22 million m3was crude oil contaminated. As exposure of more than 20 years under atmospheric conditions of Kuwait, the crude oil has volatile hydrocarbons and covered heavy oily sludge under the crude oil lake. One of crude oil contaminated soil which located Burgan Oilfield area was collected by Kuwait Oil Company and got by H-plus Company. This contaminated soil has about 42% crude oil and could not biodegraded itself due to the extremely high toxicity. This contaminated soil was separated by 2mm sieve for removal oil sludge ball. Total petroleum hydrocarbons (TPH) was analysis by GC FID and initial TPH concentration was average 48,783 mg/kg. Ten grams of the contaminated soil replaced in two micro reactors with 20mL of bio surfactant produce microorganism. Reactor 1 was added 0.1g powder hemoglobin and other reactor was not added hemoglobin at time 0 day. Those reactors shake 120 rpm on the shaker for 7 days and CO2 produced about 150mg/L per day. After 7 days under the slurry systems, the rest days operated by hemoglobin as primary carbon source for enhanced biodegradation. The crude oil contaminated soil was degraded from 48,783mg/kg to 20,234mg/kg by slurry process and final TPH concentration degraded 11,324mg/kg for 21days. Therefore, highly contaminated soil by crude oil will be combined bio slurry process and biodegradation process with hemoglobin as bio catalytic source. Keywords: crude-oil contaminated soil, bio slurry, biodegradation, hemoglobin ACKOWLEDGEMENTS This project was supported by the Korea Ministry of Environment (MOE) GAIA Program

  17. Subordinated Levy Processes and Applications to Crude Oil Options

    Noureddine Krichene

    2005-01-01

    One approach to oil markets is to treat oil as an asset, besides its role as a commodity. Speculative and nonspeculative activity by investors in the derivatives markets could be responsible for a sizable increase in oil prices. This paper recognizes both the consumption and investment aspects of crude oil and proposes Levy processes for modeling uncertainty and options pricing. Calibration to crude oil futures' options shows high volatility of oil futures prices, fat-tailed, and right-skewed...

  18. Crude glycerin in the supplement for beef cattle on pasture

    San Vito, Elias [UNESP

    2015-01-01

    Four experiments were conducted during the dry and rainy season, in order to assess the increasing concentrations of crude glycerin (80% glycerol) in the supplement of young Nellore grazing tropical grass, on intake, digestibility, ruminal fermentation, rumen microorganism profile, performance, methane emission, and carcass and meat quality traits. The treatment consist of supplements with increasing concentrations (0, 70, 140, 210, and 280 g/kg DM basis of supplement) of crude glycerin, fed ...

  19. Bioremediation of crude oil spills in marine and terrestrial environments

    Prince, R.C.

    1995-01-01

    Bioremediation can be a safe and effective tool for dealing with crude oil spills, as demonstrated during the cleanup following the Exxon Valdez spill in Alaska. Crude oil has also been spilled on land, and bioremediation is a promising option for land spills too. Nevertheless, there are still areas where understanding of the phenomenon is rather incomplete. Research groups around the world are addressing these problems, and this symposium provides an excellent overview of some of this work

  20. OPEC announcements and their effects on crude oil prices

    Lin, Sharon Xiaowen; Tamvakis, Michael

    2010-01-01

    We investigate evidence on the effects of OPEC announcements on world oil prices by examining announcements from both official conferences and ministerial meetings on major international crudes, including the key benchmarks and several other heavy and light grades. With data from 1982 to 2008, we use event study methodology and find differentiation in the magnitude and significance of market responses to OPEC quota decisions under different price bands. We also find some (weak) evidence of differentiation between light and heavy crude grades. (author)

  1. Investigation of Heavy Organics Precipitation from Nigerian Crude ...

    ADOWIE PERE

    ABSTRACT: The effects of mixing two n-alkane solvents on the precipitation of heavy organics in crude oil were carried out. The crude oil sample sourced from a major operative in Nigeria was distilled at 240oC and used for the precipitation experiment. The binary mixture of n-alkane solvents (C6: C10, C6: C16, C10: C14, ...

  2. New heavy crude oil flow improver increases delivery : application scenarios

    Pierce, J.; Johnston, R.; Lauzon, P. [ConocoPhillips Specialty Products Inc., Houston, TX (United States)

    2009-07-01

    Flow improvers or drag reducing agents have been used for over 25 years as a method to increase fluid flow in hydrocarbon pipelines. The technology is effective in refined projects, light and medium crude oils. This paper presented a new development in flow improver technology that allows treatment of heavy crude oil slates. It discussed case studies of flow improver treatment of heavy oils in various pipeline system as well as factors that affect commercial success. tabs., figs.

  3. Kurdistan crude oils as feedstock for production of aromatics

    Abdulsalam R. Karim

    2017-05-01

    Full Text Available Crude oils from various locations in Iraqi Kurdistan were fully evaluated, so that enables refiners to improve their operation by selecting the best crude oil that yields high naphtha content to be used as a catalytic reforming feedstock after determination of total sulfur content and then de sulfurizing them, then cyclizing or reforming these sweet naphtha cuts to produce aromatic fractions which can be split into benzene, toluene, and xylenes.

  4. Pricing and crude oil self-sufficiency. [Canada

    1979-11-01

    How Canada should go about achieving crude oil self-sufficiency and who should develop Canada's petroleum resources are discussed. The degree of urgency and the level of commitment required by government, industry, and consumers are evaluated. What the price should be of Canadian crude oil and who should establish this price are also discussed. The economic aspects of investment, return, and taxation are also included. (DC)

  5. Process for removing heavy metal compounds from heavy crude oil

    Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  6. Evaluating the US government's crude oil price projections

    Williams, M.D.

    1992-01-01

    The U.S. Department of Energy's (DOE) 1991 official long run crude oil price projections are evaluated by comparing parameter averages for the forecast period (1991-2010) to parameter averages from crude oil price history (1859-1990). The parameters used in the evaluation are average price, average annual price changes, and average cycle duration (in years). All prices used in the analysis are annual prices in constant 1990 dollars per barrel. 13 figs

  7. Transcriptome and proteomic analyses reveal multiple differences associated with chloroplast development in the spaceflight-induced wheat albino mutant mta.

    Kui Shi

    Full Text Available Chloroplast development is an integral part of plant survival and growth, and occurs in parallel with chlorophyll biosynthesis. However, little is known about the mechanisms underlying chloroplast development in hexaploid wheat. Here, we obtained a spaceflight-induced wheat albino mutant mta. Chloroplast ultra-structural observation showed that chloroplasts of mta exhibit abnormal morphology and distribution compared to wild type. Photosynthetic pigments content was also significantly decreased in mta. Transcriptome and chloroplast proteome profiling of mta and wild type were done to identify differentially expressed genes (DEGs and proteins (DEPs, respectively. In total 4,588 DEGs including 1,980 up- and 2,608 down-regulated, and 48 chloroplast DEPs including 15 up- and 33 down-regulated were identified in mta. Classification of DEGs revealed that most were involved in chloroplast development, chlorophyll biosynthesis, or photosynthesis. Besides, transcription factors such as PIF3, GLK and MYB which might participate in those pathways were also identified. The correlation analysis between DEGs and DEPs revealed that the transcript-to-protein in abundance was functioned into photosynthesis and chloroplast relevant groups. Real time qPCR analysis validated that the expression level of genes encoding photosynthetic proteins was significantly decreased in mta. Together, our results suggest that the molecular mechanism for albino leaf color formation in mta is a thoroughly regulated and complicated process. The combined analysis of transcriptome and proteome afford comprehensive information for further research on chloroplast development mechanism in wheat. And spaceflight provides a potential means for mutagenesis in crop breeding.

  8. Beyond the crude oil and gas reserves

    Sote, K.

    1993-01-01

    Petroleum remains the greatest jewel of inestimable value in both the local and international treasure hunts for cheap energy source and viable investment options the world over. The diverse business potentials and favourable government policies in Nigeria aimed specifically at stimulating investments in the up streams, midstream and downstream industries need to be tapped by both indigenous and foreign investors alike. Beyond the crude oil and gas reserves' is therefore our modest effort to support such policies, sensitise the Nigerian petroleum industry and promote more dynamic awareness for the varied business opportunities abound in this sector of the economy. The main objective or this publication is to bring to a wider audience within and outside the oil industry a spectrum of such salient opportunities therein. The publication further presents in a lucid and consize form the hidden potentials yet to be harnessed, captures the essence of such investments, identifies the inherent problems in Nigeria peculiar circumstance and thus provides a detailed guide to address such short-coming, viz. Inadequate and poor knowledge of petroleum industry, its operation, by products and their correct applications. - Lack of understanding of the intricacies, realities and technicalities of petroleum business in general. - Poor financial resources, management style, operational and marketing strategies man power and human resources development.- Dirge of information, lack of professional advice and technical service support on the varied business opportunities for diversification. Apathy on the part of the investors themselves to seek for professional support from competent oil consultants, technocrats, institutionalised authorities on petroleum and related matters, amongst others. In summary, the book is divided into ten chapters with illustrations, graphics, drawings, sketches and incorporating figures, statistics, business reports, marketing results, feasibility studies

  9. The impact of energy derivatives on the crude oil market

    Fleming, J.; Ostdiek, B. [Jones Graduate School of Management, Rice University, MS 531, P.O. Box 1892 Houston, TX (United States)

    1999-04-01

    We examine the effects of energy derivatives trading on the crude oil market. There is a common public and regulatory perception that derivative securities increase volatility and can have a destabilizing effect on the underlying market. Consistent with this view, we find an abnormal increase in volatility for three consecutive weeks following the introduction of NYMEX crude oil futures. While there is also evidence of a longer-term volatility increase, this is likely due to exogenous factors, such as the continuing deregulation of the energy markets. Subsequent introductions of crude oil options and derivatives on other energy commodities have no effect on crude oil volatility. We also examine the effects of derivatives trading on the depth and liquidity of the crude oil market. This analysis reveals a strong inverse relation between the open interest in crude oil futures and spot market volatility. Specifically, when open interest is greater, the volatility shock associated with a given unexpected increase in volume is much smaller. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Microbial degradation of resins fractionated from Arabian light crude oil

    Venkateswaran, K.; Hoaki, T.; Kato, M.; Maruyama, T.

    1995-01-01

    Sediment samples from the Japanese coasts were screened for microorganisms able to degrade resin components of crude oil. A mixed population that could degrade 35% of 5000 ppm resin in 15 days was obtained. This population also metabolized 50% of saturates and aromatics present in crude oil (5000 ppm) in 7 days. A Pseudomonas sp., isolated from the mixed population, emulsified and degraded 30% of resins. It also degraded saturates and aromatics (30%) present in crude oil (5000 ppm). These results were obtained from Iatroscan analysis. Degradation of crude oil was also analyzed by gas chromatography (GC). The peaks corresponding to known aliphatic hydrocarbons in crude oil greatly decreased within the first two days of incubation in the cultures of the RY-mixed population and of Pseudomonas strain UN3. Aromatic compounds detected as a broad peak by GC were significantly degraded at day 7 by Pseudomonas strain UN3, and at day 15 by the RY-mixed population. Investigations are ongoing to determine the genetic basis for the ability of these organisms to grow on the resin fractions of crude oil as a sole source of carbon and energy. 28 refs., 4 figs., 1 tab

  11. A refined approach: Saudi Arabia moves beyond crude

    Krane, Jim

    2015-01-01

    Saudi Arabia's role in global energy markets is changing. The kingdom is reshaping itself as a supplier of refined petroleum products while moving beyond its long-held role as a simple exporter of crude oil. This change is commensurate with the typical development trajectory of a state progressing to a more advanced stage of global economic integration. Gains from increased refining include reducing fuel imports and capturing margins now bequeathed to competitors. Refining also allows the kingdom to export its heavy crude oil to a wider array of customers, beyond select importers configured to handle heavy crudes. However, the move also presents strategic complications. The world's 'swing supplier' of oil may grow less willing or able to adjust supply to suit market demands. In the process, Saudi Arabia may have to update the old “oil for security” relationship that links it with Washington, augmenting it with a more diverse set of economic and investment ties with individual companies and countries, including China. -- Highlights: •Saudi Arabia is diverting crude oil into an expanding refining sector. •In doing so, the kingdom is moving beyond its role as global “swing supplier” of crude oil. •The kingdom will benefit from increased refining, including enhanced demand for heavy crude. •Strategic complications may force it to seek security partners beyond Washington

  12. Enbridge system : crude types, transportation and handling systems

    Anand, A. [Enbridge Corp., Edmonton, AB (Canada)

    2009-07-01

    The supply of crude oil from the Western Canada Sedimentary Basin is expected to increase by approximately 2.1 million barrels per day by 2015. The crudes that Enbridge handles range from 19 API to 40 API and 0.1 per cent sulphur to 4.7 per cent sulphur. The diverse supply of crude oil that the Enbridge system handles includes conventional heavy, synthetic heavy, heavy high tan, heavy low residual, medium, light sour, heavy sour, light sweet, light sweet synthetic, condensate and olefinic crudes. This presentation discussed Enbridge's plans for infrastructure expansion, crude types and quality assurance program. The company's infrastructure plans include the expansion of regional pipelines to bring more supplies to the mainline; expansion of the mainline capacity to existing markets; and providing pipeline access to new markets. Merchant storage terminals will be provided in some locations. The quality of various crude types will be maintained through judicious sequencing and tank bottoms crossings. tabs., figs.

  13. Modeling of well drilling heating on crude oil using microwave

    Muntini, Melania Suweni, E-mail: melania@physics.its.ac.id; Pramono, Yono Hadi; Yustiana [Physics Department, Institut Teknologi Sepuluh Nopember, Surabaya Kampus ITS, Sukolilo, Surabaya 60111 (Indonesia)

    2016-03-11

    As the world’s oil reserves are dwindling, some researchers have been prompted to make a breakthrough to further improve the efficiency of exploration and production. One of the technologies used is heating the crude oil. This paper presents the modeling results of heat treatment on crude oil using microwave energy. Modeling is conducted by assuming that the diameter of the well is 11,16 cm, the heat source is applied on the surface of the well, and the cut-off frequency in the air and on crude oil are 1,56 GHz. and 0.91 GHz, respectively. The energy generated by the microwave radiation is converted into heat energy which is absorbed by the crude oil. Consequently, this energy increases the temperature of crude oil through a heat transfer mechanism. The results obtained showed that the temperature of crude oil is about 200°C at a depth of 62.5cm, and at a distance of 3 cm from the center of the well. Temperature along the well follows an exponential function, which is from the center of the well in the direction radially outward from the cylinder axis. It has been observed that the temperature decreases as measured from the well surface along the cylinder.

  14. Contents of lecithin and choline in crude drugs.

    Yamasaki, K; Kikuoka, M; Nishi, H; Kokusenya, Y; Miyamoto, T; Matsuo, M; Sato, T

    1994-01-01

    The determination of lecithin and choline in crude drugs was established by a combination of high performance liquid chromatography (HPLC) with electrochemical detector (ECD) and enzyme reaction. Lecithin in crude drugs extracted with a mixture of chloroform-methanol (2:1) at room temperature was hydrolyzed by phospholipase D. The hydrolyzate was injected to HPLC, and choline was separated from impurities by reverse phase column. The choline was converted to betaine and hydrogen peroxide by passing through column packed with immobilized choline oxidase. This hydrogen peroxide was detected by ECD. The peak area of hydrogen peroxide derived from lecithin was proportional to the concentration of lecithin from 0.10 to 1.52 microgram/ml. Choline in crude drugs was extracted with ethanol under reflux and determined under the same HPLC conditions as lecithin. The peak area of hydrogen peroxide derived from choline was proportional to the concentration of choline from 0.01 to 0.45 microgram/ml. The contents of lecithin and choline in 31 kinds of crude drugs were determined by these established methods. The results showed that Cervi Parvum Cornu, Kokurozin, Foenigraeci Semen and Psoraleae Semen contained more lecithin than other crude drugs, while Angelicae Radix, Foenigraeci Semen, Psoraleae Semen, and especially Hippocampus were found to contain more choline than other crude drugs.

  15. The impact of energy derivatives on the crude oil market

    Fleming, J.; Ostdiek, B.

    1999-01-01

    We examine the effects of energy derivatives trading on the crude oil market. There is a common public and regulatory perception that derivative securities increase volatility and can have a destabilizing effect on the underlying market. Consistent with this view, we find an abnormal increase in volatility for three consecutive weeks following the introduction of NYMEX crude oil futures. While there is also evidence of a longer-term volatility increase, this is likely due to exogenous factors, such as the continuing deregulation of the energy markets. Subsequent introductions of crude oil options and derivatives on other energy commodities have no effect on crude oil volatility. We also examine the effects of derivatives trading on the depth and liquidity of the crude oil market. This analysis reveals a strong inverse relation between the open interest in crude oil futures and spot market volatility. Specifically, when open interest is greater, the volatility shock associated with a given unexpected increase in volume is much smaller. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Stable megadalton TOC-TIC supercomplexes as major mediators of protein import into chloroplasts.

    Chen, Lih-Jen; Li, Hsou-Min

    2017-10-01

    Preproteins are believed to be imported into chloroplasts through membrane contact sites where the translocon complexes of the outer (TOC) and inner (TIC) envelope membranes are assembled together. However, a single TOC-TIC supercomplex containing preproteins undergoing active import has not yet been directly observed. We optimized the blue native polyacrylamide gel electrophoresis (PAGE) (BN-PAGE) system to detect and resolve megadalton (MD)-sized complexes. Using this optimized system, the outer-membrane channel Toc75 from pea chloroplasts was found in at least two complexes: the 880-kD TOC complex and a previously undetected 1-MD complex. Two-dimensional BN-PAGE immunoblots further showed that Toc75, Toc159, Toc34, Tic20, Tic56 and Tic110 were all located in the 880-kD to 1.3-MD region. During active preprotein import, preproteins were transported mostly through the 1-MD complex and a smaller amount of preproteins was also detected in a complex of 1.25 MD. Antibody-shift assays showed that the 1-MD complex is a TOC-TIC supercomplex containing at least Toc75, Toc159, Toc34 and Tic110. Results from crosslinking and import with Arabidopsis chloroplasts suggest that the 1.25-MD complex is also a supercomplex. Our data provide direct evidence supporting that chloroplast preproteins are imported through TOC-TIC supercomplexes, and also provide the first size estimation of these supercomplexes. Furthermore, unlike in mitochondria where translocon supercomplexes are only transiently assembled during preprotein import, in chloroplasts at least some of the supercomplexes are preassembled stable structures. © 2017 The Authors The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

  17. Chloroplast genome resources and molecular markers differentiate rubber dandelion species from weedy relatives.

    Zhang, Yingxiao; Iaffaldano, Brian J; Zhuang, Xiaofeng; Cardina, John; Cornish, Katrina

    2017-02-02

    Rubber dandelion (Taraxacum kok-saghyz, TK) is being developed as a domestic source of natural rubber to meet increasing global demand. However, the domestication of TK is complicated by its colocation with two weedy dandelion species, Taraxacum brevicorniculatum (TB) and the common dandelion (Taraxacum officinale, TO). TB is often present as a seed contaminant within TK accessions, while TO is a pandemic weed, which may have the potential to hybridize with TK. To discriminate these species at the molecular level, and facilitate gene flow studies between the potential rubber crop, TK, and its weedy relatives, we generated genomic and marker resources for these three dandelion species. Complete chloroplast genome sequences of TK (151,338 bp), TO (151,299 bp), and TB (151,282 bp) were obtained using the Illumina GAII and MiSeq platforms. Chloroplast sequences were analyzed and annotated for all the three species. Phylogenetic analysis within Asteraceae showed that TK has a closer genetic distance to TB than to TO and Taraxacum species were most closely related to lettuce (Lactuca sativa). By sequencing multiple genotypes for each species and testing variants using gel-based methods, four chloroplast Single Nucleotide Polymorphism (SNP) variants were found to be fixed between TK and TO in large populations, and between TB and TO. Additionally, Expressed Sequence Tag (EST) resources developed for TO and TK permitted the identification of five nuclear species-specific SNP markers. The availability of chloroplast genomes of these three dandelion species, as well as chloroplast and nuclear molecular markers, will provide a powerful genetic resource for germplasm differentiation and purification, and the study of potential gene flow among Taraxacum species.

  18. The First Complete Chloroplast Genome Sequences in Actinidiaceae: Genome Structure and Comparative Analysis.

    Yao, Xiaohong; Tang, Ping; Li, Zuozhou; Li, Dawei; Liu, Yifei; Huang, Hongwen

    2015-01-01

    Actinidia chinensis is an important economic plant belonging to the basal lineage of the asterids. Availability of a complete Actinidia chloroplast genome sequence is crucial to understanding phylogenetic relationships among major lineages of angiosperms and facilitates kiwifruit genetic improvement. We report here the complete nucleotide sequences of the chloroplast genomes for Actinidia chinensis and A. chinensis var deliciosa obtained through de novo assembly of Illumina paired-end reads produced by total DNA sequencing. The total genome size ranges from 155,446 to 157,557 bp, with an inverted repeat (IR) of 24,013 to 24,391 bp, a large single copy region (LSC) of 87,984 to 88,337 bp and a small single copy region (SSC) of 20,332 to 20,336 bp. The genome encodes 113 different genes, including 79 unique protein-coding genes, 30 tRNA genes and 4 ribosomal RNA genes, with 16 duplicated in the inverted repeats, and a tRNA gene (trnfM-CAU) duplicated once in the LSC region. Comparisons of IR boundaries among four asterid species showed that IR/LSC borders were extended into the 5' portion of the psbA gene and IR contraction occurred in Actinidia. The clap gene has been lost from the chloroplast genome in Actinidia, and may have been transferred to the nucleus during chloroplast evolution. Twenty-seven polymorphic simple sequence repeat (SSR) loci were identified in the Actinidia chloroplast genome. Maximum parsimony analyses of a 72-gene, 16 taxa angiosperm dataset strongly support the placement of Actinidiaceae in Ericales within the basal asterids.

  19. Phosphoinositides play differential roles in regulating phototropin1- and phototropin2-mediated chloroplast movements in Arabidopsis.

    Chhavi Aggarwal

    Full Text Available Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC, PI3-kinase (PI3K and PI4-kinase (PI4K on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K activities are more restricted to phot1- and phot2-induced weak-light responses. The inactivation of PI3K and PI4K by wortmannin and LY294002 severely affected the weak blue-light-activated accumulation response but had little effect on the strong blue-light-activated avoidance response. The inhibitory effect observed with PI metabolism inhibitors is, at least partly, due to a disturbance in Ca(2+ ((c signaling. Using the transgenic aequorin system, we show that the application of these inhibitors suppresses the blue-light-induced transient Ca(2+ ((c rise. These results demonstrate the importance of PIs in chloroplast movements, with the PI(4,5P2-PLC pathway involved in phot2 signaling while PI3K and PI4K are required for the phot1- and phot2-induced accumulation response. Our results suggest that these PIs modulate cytosolic Ca(2+ signaling during movements.

  20. Phosphoinositides play differential roles in regulating phototropin1- and phototropin2-mediated chloroplast movements in Arabidopsis.

    Aggarwal, Chhavi; Labuz, Justyna; Gabryś, Halina

    2013-01-01

    Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI) metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC), PI3-kinase (PI3K) and PI4-kinase (PI4K) on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5)P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K activities are more restricted to phot1- and phot2-induced weak-light responses. The inactivation of PI3K and PI4K by wortmannin and LY294002 severely affected the weak blue-light-activated accumulation response but had little effect on the strong blue-light-activated avoidance response. The inhibitory effect observed with PI metabolism inhibitors is, at least partly, due to a disturbance in Ca(2+) ((c)) signaling. Using the transgenic aequorin system, we show that the application of these inhibitors suppresses the blue-light-induced transient Ca(2+) ((c)) rise. These results demonstrate the importance of PIs in chloroplast movements, with the PI(4,5)P2-PLC pathway involved in phot2 signaling while PI3K and PI4K are required for the phot1- and phot2-induced accumulation response. Our results suggest that these PIs modulate cytosolic Ca(2+) signaling during movements.

  1. The Complete Chloroplast Genome Sequences of the Medicinal Plant Forsythia suspensa (Oleaceae

    Wenbin Wang

    2017-10-01

    Full Text Available Forsythia suspensa is an important medicinal plant and traditionally applied for the treatment of inflammation, pyrexia, gonorrhea, diabetes, and so on. However, there is limited sequence and genomic information available for F. suspensa. Here, we produced the complete chloroplast genomes of F. suspensa using Illumina sequencing technology. F. suspensa is the first sequenced member within the genus Forsythia (Oleaceae. The gene order and organization of the chloroplast genome of F. suspensa are similar to other Oleaceae chloroplast genomes. The F. suspensa chloroplast genome is 156,404 bp in length, exhibits a conserved quadripartite structure with a large single-copy (LSC; 87,159 bp region, and a small single-copy (SSC; 17,811 bp region interspersed between inverted repeat (IRa/b; 25,717 bp regions. A total of 114 unique genes were annotated, including 80 protein-coding genes, 30 tRNA, and four rRNA. The low GC content (37.8% and codon usage bias for A- or T-ending codons may largely affect gene codon usage. Sequence analysis identified a total of 26 forward repeats, 23 palindrome repeats with lengths >30 bp (identity > 90%, and 54 simple sequence repeats (SSRs with an average rate of 0.35 SSRs/kb. We predicted 52 RNA editing sites in the chloroplast of F. suspensa, all for C-to-U transitions. IR expansion or contraction and the divergent regions were analyzed among several species including the reported F. suspensa in this study. Phylogenetic analysis based on whole-plastome revealed that F. suspensa, as a member of the Oleaceae family, diverged relatively early from Lamiales. This study will contribute to strengthening medicinal resource conservation, molecular phylogenetic, and genetic engineering research investigations of this species.

  2. The Complete Chloroplast Genome of Ye-Xing-Ba (Scrophularia dentata; Scrophulariaceae), an Alpine Tibetan Herb.

    Ni, Lianghong; Zhao, Zhili; Dorje, Gaawe; Ma, Mi

    2016-01-01

    Scrophularia dentata is an important Tibetan medicinal plant and traditionally used for the treatment of exanthema and fever in Traditional Tibetan Medicine (TTM). However, there is little sequence and genomic information available for S. dentata. In this paper, we report the complete chloroplast genome sequence of S. dentata and it is the first sequenced member of the Sect. Tomiophyllum within Scrophularia (Scrophulariaceae). The gene order and organization of the chloroplast genome of S. dentata are similar to other Lamiales chloroplast genomes. The plastome is 152,553 bp in length and includes a pair of inverted repeats (IRs) of 25,523 bp that separate a large single copy (LSC) region of 84,058 bp and a small single copy (SSC) region of 17,449 bp. It has 38.0% GC content and includes 114 unique genes, of which 80 are protein-coding, 30 are transfer RNA, and 4 are ribosomal RNA. Also, it contains 21 forward repeats, 19 palindrome repeats and 41 simple sequence repeats (SSRs). The repeats and SSRs within S. dentata were compared with those of S. takesimensis and present certain discrepancies. The chloroplast genome of S. dentata was compared with other five publicly available Lamiales genomes from different families. All the coding regions and non-coding regions (introns and intergenic spacers) within the six chloroplast genomes have been extracted and analysed. Furthermore, the genome divergent hotspot regions were identified. Our studies could provide basic data for the alpine medicinal species conservation and molecular phylogenetic researches of Scrophulariaceae and Lamiales.

  3. The Complete Chloroplast Genome of Ye-Xing-Ba (Scrophularia dentata; Scrophulariaceae, an Alpine Tibetan Herb.

    Lianghong Ni

    Full Text Available Scrophularia dentata is an important Tibetan medicinal plant and traditionally used for the treatment of exanthema and fever in Traditional Tibetan Medicine (TTM. However, there is little sequence and genomic information available for S. dentata. In this paper, we report the complete chloroplast genome sequence of S. dentata and it is the first sequenced member of the Sect. Tomiophyllum within Scrophularia (Scrophulariaceae. The gene order and organization of the chloroplast genome of S. dentata are similar to other Lamiales chloroplast genomes. The plastome is 152,553 bp in length and includes a pair of inverted repeats (IRs of 25,523 bp that separate a large single copy (LSC region of 84,058 bp and a small single copy (SSC region of 17,449 bp. It has 38.0% GC content and includes 114 unique genes, of which 80 are protein-coding, 30 are transfer RNA, and 4 are ribosomal RNA. Also, it contains 21 forward repeats, 19 palindrome repeats and 41 simple sequence repeats (SSRs. The repeats and SSRs within S. dentata were compared with those of S. takesimensis and present certain discrepancies. The chloroplast genome of S. dentata was compared with other five publicly available Lamiales genomes from different families. All the coding regions and non-coding regions (introns and intergenic spacers within the six chloroplast genomes have been extracted and analysed. Furthermore, the genome divergent hotspot regions were identified. Our studies could provide basic data for the alpine medicinal species conservation and molecular phylogenetic researches of Scrophulariaceae and Lamiales.

  4. High-throughput sequencing of three Lemnoideae (duckweeds chloroplast genomes from total DNA.

    Wenqin Wang

    Full Text Available BACKGROUND: Chloroplast genomes provide a wealth of information for evolutionary and population genetic studies. Chloroplasts play a particularly important role in the adaption for aquatic plants because they float on water and their major surface is exposed continuously to sunlight. The subfamily of Lemnoideae represents such a collection of aquatic species that because of photosynthesis represents one of the fastest growing plant species on earth. METHODS: We sequenced the chloroplast genomes from three different genera of Lemnoideae, Spirodela polyrhiza, Wolffiella lingulata and Wolffia australiana by high-throughput DNA sequencing of genomic DNA using the SOLiD platform. Unfractionated total DNA contains high copies of plastid DNA so that sequences from the nucleus and mitochondria can easily be filtered computationally. Remaining sequence reads were assembled into contiguous sequences (contigs using SOLiD software tools. Contigs were mapped to a reference genome of Lemna minor and gaps, selected by PCR, were sequenced on the ABI3730xl platform. CONCLUSIONS: This combinatorial approach yielded whole genomic contiguous sequences in a cost-effective manner. Over 1,000-time coverage of chloroplast from total DNA were reached by the SOLiD platform in a single spot on a quadrant slide without purification. Comparative analysis indicated that the chloroplast genome was conserved in gene number and organization with respect to the reference genome of L. minor. However, higher nucleotide substitution, abundant deletions and insertions occurred in non-coding regions of these genomes, indicating a greater genomic dynamics than expected from the comparison of other related species in the Pooideae. Noticeably, there was no transition bias over transversion in Lemnoideae. The data should have immediate applications in evolutionary biology and plant taxonomy with increased resolution and statistical power.

  5. Production of biopharmaceuticals and vaccines in plants via the chloroplast genome.

    Daniell, Henry

    2006-10-01

    Transgenic plants offer many advantages, including low cost of production (by elimination of fermenters), storage and transportation; heat stability; and absence of human pathogens. When therapeutic proteins are orally delivered, plant cells protect antigens in the stomach through bioencapsulation and eliminate the need for expensive purification and sterile injections, in addition to development of both systemic and mucosal immunity. Chloroplast genetic engineering offers several advantages, including high levels of transgene expression, transgene containment via maternal inheritance and multi-gene expression in a single transformation event. Hyper-expression of vaccine antigens against cholera, tetanus, anthrax, plague or canine parvovirus (4-31% of total soluble protein, tsp) in transgenic chloroplasts (leaves) or non-green plastids (carrots, tomato), as well as the availability of antibiotic-free selectable markers or the ability to excise selectable marker genes, facilitate oral delivery. Hyper-expression of several therapeutic proteins, including human serum albumin (11.1% tsp), somatotropin (7% tsp), interferon-gamma (6% tsp), anti-microbial peptide (21.5% tsp), facilitates efficient and economic purification. Also, the presence of chaperones and enzymes in chloroplasts facilitate assembly of complex multi-subunit proteins and correct folding of human blood proteins with proper disulfide bonds. Functionality of chloroplast-derived vaccine antigens and therapeutic proteins has been demonstrated by several assays, including the macrophage lysis assay, GM1-ganglioside binding assay, protection of HeLa cells or human lung carcinoma cells against encephalomyocarditis virus, systemic immune response, protection against pathogen challenge, and growth or inhibition of cell cultures. Thus, transgenic chloroplasts are ideal bioreactors for production of functional human and animal therapeutic proteins in an environmentally friendly manner.

  6. A dynamic phase microscopic study of optical characteristics of individual chloroplasts.

    Tychinsky, V P; Kretushev, A V; Vyshenskaya, T V; Tikhonov, A N

    2004-10-11

    Dynamic phase microscopy (DPM) allows the monitoring of optical path difference (or phase height), h(x,y,t) approximately integraln(x,y,z,t)dz, an integral refractive index projection of the medium, n(x,y,z,t), in optically transparent biological specimens at high spatial and temporal resolutions. In this study, DPM was used for the analysis of fluctuations in the optical characteristics of individual bean chloroplasts in various metabolic states. A "phase image" of an individual chloroplast, which represents a three-dimensional plot of the "phase height", was obtained for the first time, and the frequency spectra of the fluctuations of h(x,y,t) were investigated. The fluctuation patterns, i.e., the intensity and the frequency spectra of phase height fluctuations in bean chloroplasts (Class B) were found to depend on their metabolic state. Under conditions of noncyclic (or pseudocyclic) electron transport, the fluctuations displayed characteristic frequencies in the range of 0.25-0.6 Hz and were space-time-correlated in the chloroplast domains with the cross sizes of approximately 2 microm. The fluctuation intensity decreased in the presence of uncouplers (nigericin and valinomycin, 20 microM). A stronger (in comparison with 20 microM valinomycin) effect of 20 microM nigericin suggests that the light-induced generation of the transmembrane pH difference (DeltapH) makes the main contribution to the increment of space-correlated fluctuations of h(x,y,t). Studies of chloroplasts incubated in media of various osmolarity (50-500 mM sucrose) have shown that structural changes in thylakoids are among other factors responsible for phase height fluctuations.

  7. A set of primers for analyzing chloroplast DNA diversity in Citrus and related genera.

    Cheng, Yunjiang; de Vicente, M Carmen; Meng, Haijun; Guo, Wenwu; Tao, Nengguo; Deng, Xiuxin

    2005-06-01

    Chloroplast simple sequence repeat (cpSSR) markers in Citrus were developed and used to analyze chloroplast diversity of Citrus and closely related genera. Fourteen cpSSR primer pairs from the chloroplast genomes of tobacco (Nicotiana tabacum L.) and Arabidopsis were found useful for analyzing the Citrus chloroplast genome (cpDNA) and recoded with the prefix SPCC (SSR Primers for Citrus Chloroplast). Eleven of the 14 primer pairs revealed some degree of polymorphism among 34 genotypes of Citrus, Fortunella, Poncirus and some of their hybrids, with polymorphism information content (PIC) values ranging from 0.057 to 0.732, and 18 haplotypes were identified. The cpSSR data were analyzed with NTSYS-pc software, and the genetic relationships suggested by the unweighted pair group method based on arithmetic means (UPGMA) dendrogram were congruent with previous taxonomic investigations: the results showed that all samples fell into seven major clusters, i.e., Citrus medica L., Poncirus, Fortunella, C. ichangensis Blanco, C. reticulata Swingle, C. aurantifolia (Christm.) Swingle and C. grandis (L.) Osbeck. The results of previous studies combined with our cpSSR analyses revealed that: (1) Calamondin (C. madurensis Swingle) is the result of hybridization between kumquat (Fortunella) and mandarin (C. reticulata), where kumquat acted as the female parent; (2) Ichang papeda (C. ichangensis) has a unique taxonomic status; and (3) although Bendiguangju mandarin (C. reticulata) and Satsuma mandarin (C. reticulata) are similar in fruit shape and leaf morphology, they have different maternal parents. Bendiguangju mandarin has the same cytoplasm as sweet orange (C. sinensis), whereas Satsuma mandarin has the cytoplasm of C. reticulata. Seventeen PCR products from SPCC1 and 21 from SPCC11 were cloned and sequenced. The results revealed that mononucleotide repeats as well as insertions and deletions of small segments of DNA were associated with SPCC1 polymorphism, whereas polymorphism

  8. 77 FR 55817 - Delek Crude Logistics, LLC; Notice of Petition for Waiver

    2012-09-11

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. OR12-19-000] Delek Crude Logistics, LLC; Notice of Petition for Waiver Take notice that on June 11, 2012, Delek Crude Logistics, LLC... East Texas Crude Logistics crude oil pipeline system. Any person desiring to intervene or to protest in...

  9. Chloroplast DNA codon use: evidence for selection at the psb A locus based on tRNA availability.

    Morton, B R

    1993-09-01

    Codon use in the three sequenced chloroplast genomes (Marchantia, Oryza, and Nicotiana) is examined. The chloroplast has a bias in that codons NNA and NNT are favored over synonymous NNC and NNG codons. This appears to be a consequence of an overall high A + T content of the genome. This pattern of codon use is not followed by the psb A gene of all three genomes and other psb A sequences examined. In this gene, the codon use favors NNC over NNT for twofold degenerate amino acids. In each case the only tRNA coded by the genome is complementary to the NNC codon. This codon use is similar to the codon use by chloroplast genes examined from Chlamydomonas reinhardtii. Since psb A is the major translation product of the chloroplast, this suggests that selection is acting on the codon use of this gene to adapt codons to tRNA availability, as previously suggested for unicellular organisms.

  10. Vaccination via Chloroplast Genetics: Affordable Protein Drugs for the Prevention and Treatment of Inherited or Infectious Human Diseases.

    Daniell, Henry; Chan, Hui-Ting; Pasoreck, Elise K

    2016-11-23

    Plastid-made biopharmaceuticals treat major metabolic or genetic disorders, including Alzheimer's, diabetes, hypertension, hemophilia, and retinopathy. Booster vaccines made in chloroplasts prevent global infectious diseases, such as tuberculosis, malaria, cholera, and polio, and biological threats, such as anthrax and plague. Recent advances in this field include commercial-scale production of human therapeutic proteins in FDA-approved cGMP facilities, development of tags to deliver protein drugs to targeted human cells or tissues, methods to deliver precise doses, and long-term stability of protein drugs at ambient temperature, maintaining their efficacy. Codon optimization utilizing valuable information from sequenced chloroplast genomes enhanced expression of eukaryotic human or viral genes in chloroplasts and offered unique insights into translation in chloroplasts. Support from major biopharmaceutical companies, development of hydroponic production systems, and evaluation by regulatory agencies, including the CDC, FDA, and USDA, augur well for advancing this novel concept to the clinic and revolutionizing affordable healthcare.

  11. A Comparison of the First Two Sequenced Chloroplast Genomes in Asteraceae: Lettuce and Sunflower

    Timme, Ruth E.; Kuehl, Jennifer V.; Boore, Jeffrey L.; Jansen, Robert K.

    2006-01-20

    Asteraceae is the second largest family of plants, with over 20,000 species. For the past few decades, numerous phylogenetic studies have contributed to our understanding of the evolutionary relationships within this family, including comparisons of the fast evolving chloroplast gene, ndhF, rbcL, as well as non-coding DNA from the trnL intron plus the trnLtrnF intergenic spacer, matK, and, with lesser resolution, psbA-trnH. This culminated in a study by Panero and Funk in 2002 that used over 13,000 bp per taxon for the largest taxonomic revision of Asteraceae in over a hundred years. Still, some uncertainties remain, and it would be very useful to have more information on the relative rates of sequence evolution among various genes and on genome structure as a potential set of phylogenetic characters to help guide future phylogenetic structures. By way of contributing to this, we report the first two complete chloroplast genome sequences from members of the Asteraceae, those of Helianthus annuus and Lactuca sativa. These plants belong to two distantly related subfamilies, Asteroideae and Cichorioideae, respectively. In addition to these, there is only one other published chloroplast genome sequence for any plant within the larger group called Eusterids II, that of Panax ginseng (Araliaceae, 156,318 bps, AY582139). Early chloroplast genome mapping studies demonstrated that H. annuus and L. sativa share a 22 kb inversion relative to members of the subfamily Barnadesioideae. By comparison to outgroups, this inversion was shown to be derived, indicating that the Asteroideae and Cichorioideae are more closely related than either is to the Barnadesioideae. Later sequencing study found that taxa that share this 22 kb inversion also contain within this region a second, smaller, 3.3 kb inversion. These sequences also enable an analysis of patterns of shared repeats in the genomes at fine level and of RNA editing by comparison to available EST sequences. In addition, since

  12. Photosynthetic Characteristics and Chloroplast Ultrastructure of Summer Maize Response to Different Nitrogen Supplies.

    Liu, Zheng; Gao, Jia; Gao, Fei; Liu, Peng; Zhao, Bin; Zhang, Jiwang

    2018-01-01

    Maize ( Zea mays L.) is the important crop over the world. Nitrogen (N) as necessary element affects photosynthetic characteristics and grain yield of summer maize. In this study, N0 (0 kg N ha -1 ), N1 (129 kg N ha -1 ), N2 (185 kg N ha -1 ), and N3 (300 kg N ha -1 ) was conducted using hybrid 'ZhengDan958' at Dawenkou research field (36°11'N, 117°06'E, 178 m altitude) in the North China Plain to explore the effects of N rate on photosynthetic characteristics and chloroplast ultrastructure. Gas exchange parameters, chlorophyll fluorescence parameters, leaf area index (LAI), chlorophyll SPAD value, chloroplast ultrastructure, dry matter weight and grain yield were measured. At physiological maturity stage, dry matter weight and grain yield of N2 increased by 33-52% ( P ≤ 0.05) and 6-32% ( P ≤ 0.05), respectively, compared with other treatments. During the growing from silking (R1) to milk (R3) stage, LAI of N0 and N1 were 35-38% ( P ≤ 0.05) and 9-23% ( P ≤ 0.05) less than that of N2, respectively. Chlorophyll SPAD value of N0 and N1 were 13-22% ( P ≤ 0.05) and 5-11% ( P ≤ 0.05) lower than that of N2. There was no significant difference in LAI and chlorophyll SPAD value between N2 and N3 during the period from R1 to R3 ( P > 0.05). The net photosynthetic rate ( P n ), maximal quantum efficiency of PSII ( F v / F m ) and quantum efficiency of PSII (Φ PSII ) were higher with the increase of N rate up to N2 ( P ≤ 0.05), and those of N3 were significantly less than N2 ( P ≤ 0.05). In compared with N2, the chloroplast configuration of N0 and N1 became elliptical, almost circular or irregular. The membrane of chloroplast and thylakoid resolved with growing stage, and the number of chloroplast per cell and lamellae per grana decreased under N0 and N1 treatment ( P ≤ 0.05). Under N0 and N1 treatments, summer maize had more negative photosynthetic characteristics. The more number of osmium granule and vesicle and the larger gap between lamellae were

  13. Photosynthetic Characteristics and Chloroplast Ultrastructure of Summer Maize Response to Different Nitrogen Supplies

    Zheng Liu

    2018-05-01

    Full Text Available Maize (Zea mays L. is the important crop over the world. Nitrogen (N as necessary element affects photosynthetic characteristics and grain yield of summer maize. In this study, N0 (0 kg N ha-1, N1 (129 kg N ha-1, N2 (185 kg N ha-1, and N3 (300 kg N ha-1 was conducted using hybrid ‘ZhengDan958’ at Dawenkou research field (36°11′N, 117°06′E, 178 m altitude in the North China Plain to explore the effects of N rate on photosynthetic characteristics and chloroplast ultrastructure. Gas exchange parameters, chlorophyll fluorescence parameters, leaf area index (LAI, chlorophyll SPAD value, chloroplast ultrastructure, dry matter weight and grain yield were measured. At physiological maturity stage, dry matter weight and grain yield of N2 increased by 33–52% (P ≤ 0.05 and 6–32% (P ≤ 0.05, respectively, compared with other treatments. During the growing from silking (R1 to milk (R3 stage, LAI of N0 and N1 were 35–38% (P ≤ 0.05 and 9–23% (P ≤ 0.05 less than that of N2, respectively. Chlorophyll SPAD value of N0 and N1 were 13–22% (P ≤ 0.05 and 5–11% (P ≤ 0.05 lower than that of N2. There was no significant difference in LAI and chlorophyll SPAD value between N2 and N3 during the period from R1 to R3 (P > 0.05. The net photosynthetic rate (Pn, maximal quantum efficiency of PSII (Fv/Fm and quantum efficiency of PSII (ΦPSII were higher with the increase of N rate up to N2 (P ≤ 0.05, and those of N3 were significantly less than N2 (P ≤ 0.05. In compared with N2, the chloroplast configuration of N0 and N1 became elliptical, almost circular or irregular. The membrane of chloroplast and thylakoid resolved with growing stage, and the number of chloroplast per cell and lamellae per grana decreased under N0 and N1 treatment (P ≤ 0.05. Under N0 and N1 treatments, summer maize had more negative photosynthetic characteristics. The more number of osmium granule and vesicle and the larger gap between lamellae were shown in N3

  14. Standard guide for determining corrosivity of crude oils

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide presents some generally accepted laboratory methodologies that are used for determining the corrosivity of crude oil. 1.2 This guide does not cover detailed calculations and methods, but rather a range of approaches that have found application in evaluating the corrosivity of crude oil. 1.3 Only those methodologies that have found wide acceptance in crude oil corrosivity evaluation are considered in this guide. 1.4 This guide does not address the change in oil/water ratio caused by accumulation of water at low points in a pipeline system. 1.5 This guide is intended to assist in the selection of methodologies that can be used for determining the corrosivity of crude oil under conditions in which water is present in the liquid state (typically up to 100°C). These conditions normally occur during oil and gas production, storage, and transportation in the pipelines. 1.6 This guide does not cover the evaluation of corrosivity of crude oil at higher temperatures (typically above 300°C) that oc...

  15. E3 analysis for crude and vacuum distillation system

    Mittal, V; Zhang, J; Yang, X; Xu, Q [Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas (United States)

    2011-11-15

    Crude oil blending is a very common practice in petroleum refineries, where the main focus is to minimize the total purchase cost of crude oils under specified blending oil properties. Crude oil blending actually has significant impacts on energy consumption from heating furnaces during crude oil processing. Conceivably, furnace energy consumption from burning fuels such as natural gas, fuel oil, or propane causes huge amounts of CO{sub 2} emissions. In this paper, a methodology framework for crude oil blending and processing with simultaneous consideration of energy, emission, and economic profit (E3) is developed. It includes four stages of work: steady-state modeling, heating energy consumption calculation, emission model development, and economic evaluation. With Aspen HYSYS simulation, the developed methodology provides a quantitative support for refinery to identify an optimal E3 operating strategy. A case study is implemented to demonstrate the efficacy of this methodology. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Effect of temperature on biodegradation of crude oil

    Zekri, A.; Chaalal, O.

    2005-01-01

    An active strain of anaerobic thermophilic bacteria was isolated from the environment of the United Arab Emirates. This project studied the effect of temperature, salinity and oil concentration on biodegradation of crude oil. Oil weight loss, microbial growth and the changes of the crude oil asphaltene concentration are used to evaluate the oil degradation by this strain. A series of batch experiments was performed to study the effects of bacteria on the degradation of crude oil. The effects of oil concentration, bacteria concentration, temperature and salinity on the biodegradation were investigated. The temperatures of the studied systems were varied between 35 and 75 o C and the salt concentrations were varied between 0 and 10%. Oil concentrations were ranged from 5 to 50% by volume. Experimental work showed the bacteria employed in this project were capable of surviving the harsh environment and degrading the crude oil at various conditions. Increasing the temperature increases the rate of oil degradation by bacteria. Increasing the oil concentration in general decreases the rate of bacteria oil degradation. Salinity plays a major role on the acceleration of biodegradation process of crude oil. An optimum salinity should be determined for every studied system. The finding of this project could be used in either the treatment of oil spill or in-situ stimulation of heavy oil wells. (author)

  17. Enhanced crude oil biodegradation in soil via biostimulation.

    Al-Saleh, Esmaeil; Hassan, Ali

    2016-08-02

    Research on feasible methods for the enhancement of bioremediation in soil contaminated by crude oil is vital in oil-exporting countries such as Kuwait, where crude oil is a major pollutant and the environment is hostile to biodegradation. This study investigated the possibility of enhancing crude oil bioremediation by supplementing soil with cost-effective organic materials derived from two widespread locally grown trees, Conocarpus and Tamarix. Amendments in soils increased the counts of soil microbiota by up to 98% and enhanced their activity by up to 95.5%. The increase in the biodegradation of crude oil (75%) and high levels of alkB expression substantiated the efficiency of the proposed amendment technology for the bioremediation of hydrocarbon-contaminated sites. The identification of crude-oil-degrading bacteria revealed the dominance of the genus Microbacterium (39.6%), Sphingopyxis soli (19.3%), and Bordetella petrii (19.6%) in unamended, Conocarpus-amended, and Tamarix-amended contaminated soils, respectively. Although soil amendments favored the growth of Gram-negative bacteria and reduced bacterial diversity, the structures of bacterial communities were not significantly altered.

  18. An Improved CO2-Crude Oil Minimum Miscibility Pressure Correlation

    Hao Zhang

    2015-01-01

    Full Text Available Minimum miscibility pressure (MMP, which plays an important role in miscible flooding, is a key parameter in determining whether crude oil and gas are completely miscible. On the basis of 210 groups of CO2-crude oil system minimum miscibility pressure data, an improved CO2-crude oil system minimum miscibility pressure correlation was built by modified conjugate gradient method and global optimizing method. The new correlation is a uniform empirical correlation to calculate the MMP for both thin oil and heavy oil and is expressed as a function of reservoir temperature, C7+ molecular weight of crude oil, and mole fractions of volatile components (CH4 and N2 and intermediate components (CO2, H2S, and C2~C6 of crude oil. Compared to the eleven most popular and relatively high-accuracy CO2-oil system MMP correlations in the previous literature by other nine groups of CO2-oil MMP experimental data, which have not been used to develop the new correlation, it is found that the new empirical correlation provides the best reproduction of the nine groups of CO2-oil MMP experimental data with a percentage average absolute relative error (%AARE of 8% and a percentage maximum absolute relative error (%MARE of 21%, respectively.

  19. Chloroplast genes are expressed during intracellular symbiotic association of Vaucheria litorea plastids with the sea slug Elysia chlorotica.

    Mujer, C V; Andrews, D L; Manhart, J R; Pierce, S K; Rumpho, M E

    1996-01-01

    The marine slug Elysia chlorotica (Gould) forms an intracellular symbiosis with photosynthetically active chloroplasts from the chromophytic alga Vaucheria litorea (C. Agardh). This symbiotic association was characterized over a period of 8 months during which E. chlorotica was deprived of V. litorea but provided with light and CO2. The fine structure of the symbiotic chloroplasts remained intact in E. chlorotica even after 8 months of starvation as revealed by electron microscopy. Southern b...

  20. AT_CHLORO, a comprehensive chloroplast proteome database with subplastidial localization and curated information on envelope proteins.

    Ferro, Myriam; Brugière, Sabine; Salvi, Daniel; Seigneurin-Berny, Daphné; Court, Magali; Moyet, Lucas; Ramus, Claire; Miras, Stéphane; Mellal, Mourad; Le Gall, Sophie; Kieffer-Jaquinod, Sylvie; Bruley, Christophe; Garin, Jérôme; Joyard, Jacques; Masselon, Christophe; Rolland, Norbert

    2010-06-01

    Recent advances in the proteomics field have allowed a series of high throughput experiments to be conducted on chloroplast samples, and the data are available in several public databases. However, the accurate localization of many chloroplast proteins often remains hypothetical. This is especially true for envelope proteins. We went a step further into the knowledge of the chloroplast proteome by focusing, in the same set of experiments, on the localization of proteins in the stroma, the thylakoids, and envelope membranes. LC-MS/MS-based analyses first allowed building the AT_CHLORO database (http://www.grenoble.prabi.fr/protehome/grenoble-plant-proteomics/), a comprehensive repertoire of the 1323 proteins, identified by 10,654 unique peptide sequences, present in highly purified chloroplasts and their subfractions prepared from Arabidopsis thaliana leaves. This database also provides extensive proteomics information (peptide sequences and molecular weight, chromatographic retention times, MS/MS spectra, and spectral count) for a unique chloroplast protein accurate mass and time tag database gathering identified peptides with their respective and precise analytical coordinates, molecular weight, and retention time. We assessed the partitioning of each protein in the three chloroplast compartments by using a semiquantitative proteomics approach (spectral count). These data together with an in-depth investigation of the literature were compiled to provide accurate subplastidial localization of previously known and newly identified proteins. A unique knowledge base containing extensive information on the proteins identified in envelope fractions was thus obtained, allowing new insights into this membrane system to be revealed. Altogether, the data we obtained provide unexpected information about plastidial or subplastidial localization of some proteins that were not suspected to be associated to this membrane system. The spectral counting-based strategy was further