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Sample records for vacuolar sucrose transporter

  1. Sucrose assimilation and the role of sucrose transporters in plant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... African Journal of Biotechnology Vol. 7 (25), pp. ... Review. Sucrose assimilation and the role of sucrose transporters in plant wound response. Omodele ... Key words: Sucrose transporters, Plasma membrane, carbohydrate, sieve element, source-sink. ... pathogens (Paul et al., 2000) and results in a severe.

  2. Cloning, localization and expression analysis of vacuolar sugar transporters in the CAM plant Ananas comosus (pineapple).

    Science.gov (United States)

    Antony, Edna; Taybi, Tahar; Courbot, Mikaël; Mugford, Sam T; Smith, J Andrew C; Borland, Anne M

    2008-01-01

    In photosynthetic tissues of the CAM plant pineapple (Ananas comosus), storage of soluble sugars in the central vacuole during the daytime and their remobilization at night is required to provide carbon skeletons for nocturnal CO(2) fixation. However, soluble sugars produced photosynthetically must also be exported to support growth processes in heterotrophic tissues. To begin to address how vacuolar sugar storage and assimilate partitioning are regulated in A. comosus, degenerate PCR and cDNA library screening were used to clone three candidate sugar transporters from the leaves of this species. Subcellular localization of the three transporters was investigated via expression of YFP-fusion proteins in tobacco epidermal cells and their co-localization with subcellular markers by confocal microscopy. Using this strategy, a putative hexose transporter (AcMST1) and a putative inositol transporter (AcINT1) were identified that both localized to the tonoplast, whereas a putative sucrose transporter (AcSUT1) was found to localize to prevacuolar compartments. A cDNA (AcMST2) with high similarity to a recently characterized tonoplast hexose transporter in Arabidopsis was also identified from an A. comosus fruit EST database. Analyses of transcript abundance indicated that AcMST1 was more highly expressed in fruits compared to leaves of A. comosus, whilst transcripts of AcINT1, AcSUT1, and AcMST2 were more abundant in leaves. Transcript abundance of AcINT1, the putative inositol transporter, showed day-night changes comparable to those of other CAM-related transcripts described in Mesembryanthemum crystallinum. The results are discussed in terms of the role of vacuolar sugar transporters in regulating carbon flow during the diel cycle in CAM plants.

  3. Characterization of vacuolar amino acid transporter from Fusarium oxysporum in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lunprom, Siriporn; Pongcharoen, Pongsanat; Sekito, Takayuki; Kawano-Kawada, Miyuki; Kakinuma, Yoshimi; Akiyama, Koichi

    2015-01-01

    Fusarium oxysporum causes wilt disease in many plant families, and many genes are involved in its development or growth in host plants. A recent study revealed that vacuolar amino acid transporters play an important role in spore formation in Schizosaccharomyces pombe and Saccharomyces cerevisiae. To investigate the role of vacuolar amino acid transporters of this phytopathogenic fungus, the FOXG_11334 (FoAVT3) gene from F. oxysporum was isolated and its function was characterized. Transcription of FoAVT3 was upregulated after rapamycin treatment. A green fluorescent protein fusion of FoAvt3p was localized to vacuolar membranes in both S. cerevisiae and F. oxysporum. Analysis of the amino acid content of the vacuolar fraction and amino acid transport activities using vacuolar membrane vesicles from S. cerevisiae cells heterologously expressing FoAVT3 revealed that FoAvt3p functions as a vacuolar amino acid transporter, exporting neutral amino acids. We conclude that the FoAVT3 gene encodes a vacuolar neutral amino acid transporter.

  4. Sucrose fermentation by Saccharomyces cerevisiae lacking hexose transport.

    Science.gov (United States)

    Batista, Anderson S; Miletti, Luiz C; Stambuk, Boris U

    2004-01-01

    Sucrose is the major carbon source used by Saccharomyces cerevisiae during production of baker's yeast, fuel ethanol and several distilled beverages. It is generally accepted that sucrose fermentation proceeds through extracellular hydrolysis of the sugar, mediated by the periplasmic invertase, producing glucose and fructose that are transported into the cells and metabolized. In the present work we analyzed the contribution to sucrose fermentation of a poorly characterized pathway of sucrose utilization by S. cerevisiae cells, the active transport of the sugar through the plasma membrane and its intracellular hydrolysis. A yeast strain that lacks the major hexose transporters (hxt1-hxt7 and gal2) is incapable of growing on or fermenting glucose or fructose. Our results show that this hxt-null strain is still able to ferment sucrose due to direct uptake of the sugar into the cells. Deletion of the AGT1 gene, which encodes a high-affinity sucrose-H(+) symporter, rendered cells incapable of sucrose fermentation. Since sucrose is not an inducer of the permease, expression of the AGT1 must be constitutive in order to allow growth of the hxt-null strain on sucrose. The molecular characterization of active sucrose transport and fermentation by S. cerevisiae cells opens new opportunities to optimize yeasts for sugarcane-based industrial processes.

  5. Vacuolar iron transporter BnMEB2 is involved in enhancing iron tolerance of Brassica napus

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    Wei Zhu

    2016-09-01

    Full Text Available Iron toxicity is a major nutrient disorder that severely affects crop development and yield. Vacuolar detoxification of metal stress is an important strategy for plants to survive and adapt to this adverse environment. Vacuolar iron transporter (VIT members are involved in this process and play essential roles in iron storage and transport. In this study, a rapeseed VIT gene BnMEB2 (BnaC07g30170D was identified. BnMEB2 is a homolog to Arabidopsis MEB2 (At5g24290 and acts as a detoxifier in vacuolar sequestration of divalent metal. Transient expression analysis revealed that BnMEB2 was localized to the vacuolar membrane. Q-PCR detection showed a high expression of BnMEB2 in mature (60-day-old leaves and could be obviously induced by exogenous iron stress in both roots and leaves. Over-expressed BnMEB2 in both Arabidopsis wild type and meb2 mutant seedlings resulted in greatly improved iron tolerability with no significant changes in the expression level of other vacuolar iron transporter genes. The mutant meb2 grew slowly and its root hair elongation was inhibited under high iron concentration condition while BnMEB2 over-expressed transgenic plants of the mutant restored the phenotypes with apparently higher iron storage in roots and dramatically increased iron content in the whole plant. Taken together, these results suggested that BnMEB2 was a VIT gene in rapeseed which was necessary for safe storage and vacuole detoxification function of excess iron to enhance the tolerance of iron toxicity. This research sheds light on a potentially new strategy for attenuating hazardous metal stress from environment and improving iron biofortification in Brassicaceae crops.

  6. Diverse expression of sucrose transporter gene family in Zea mays

    Indian Academy of Sciences (India)

    2015-03-04

    Mar 4, 2015 ... In this study, we identified four sucrose transporter genes. (ZmSUT1 .... strand synthesis was done with forward and reverse primers designed at .... Qazi H. A., Paranjpe S. and Bhargava S. 2012 Stem sugar accu- mulation in ...

  7. Sucrose transporters in two members of the Scrophulariaceae with different types of transport sugar.

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    Knop, C; Voitsekhovskaja, O; Lohaus, G

    2001-05-01

    In order to study differences between sugar transport in oligosaccharide-translocating and sucrose-translocating species, two members of the Scrophulariaceae, Asarina barclaiana Pennell and Alonsoa meridionalis O. Kuntze, were analysed regarding minor-vein anatomy, sugar concentrations in leaves and phloem sap, and expression of sucrose transporters. The minor veins of Asarina barclaiana possess mainly transfer cells and modified intermediary cells and those of Alonsoa meridionalis have intermediary cells and ordinary companion cells. Phloem sap from these plants was collected by the laser-aphid-stylet technique. The main carbon transport forms in Asarina were sucrose and in Alonsoa raffinose and stachyose. The sum of the carbohydrate concentrations in the phloem sap of both species was as high as that in apoplastic phloem loaders. In Asarina the ratio of the sucrose concentration in the phloem to that in the cytosol of source cells was about 35 and the corresponding ratio in Alonsoa was about two. Sucrose transporter cDNAs were isolated from leaves of both species. By means of semi-quantitative reverse transcription-polymerase chain reaction, sucrose transporter mRNA was detected in different organs and also in the phloem sap. This is the first time that sucrose transporters have been found in oligosaccharide-translocating species and that the mRNA of these sucrose transporters has been localized directly in the phloem sap. Taken together, our observations indicate that Asarina is an apoplastic phloem loader, while the results for Alonsoa are ambiguous: some properties are typical of the symplastic phloem-loading mechanism, but probably a sucrose transporter is involved in loading and/or retrieval of sucrose into the phloem.

  8. Characterization of Gene Candidates for Vacuolar Sodium Transport from Hordeum Vulgare

    KAUST Repository

    Scheu, Arne Hagen August

    2017-05-01

    Soil salinity is a major abiotic stress for land plants, and multiple mechanisms of salt tolerance have evolved. Tissue tolerance is one of these mechanisms, which involves the sequestration of sodium into the vacuole to retain low cytosolic sodium concentrations. This enables the plant to maintain cellular functions, and ultimately maintain growth and yield. However, the molecular components involved in tissue tolerance remain elusive. Several candidate genes for vacuolar sodium sequestration have recently been identified by proteome analysis of vacuolar membranes purified from the salt-tolerant cereal Hordeum vulgare (barley). In this study, I aimed to characterize these candidates in more detail. I successfully cloned coding sequences for the majority of candidate genes with primers designed based on the barley reference genome sequence. During the course of this study a newer genome sequence with improved annotations was published, to which I also compared my observations. To study the candidate genes, I used the heterologous expression system Saccharomyces cerevisiae (yeast). I used several salt sensitive yeast strains (deficient in intrinsic sodium transporters) to test whether the candidate genes would affect their salt tolerance by mediating the sequestration of sodium into the yeast vacuole. I observed a reduction in growth upon expression for several of the gene candidate under salt-stress conditions. However, confocal microscopy suggests that most gene products are subject to degradation, and did not localize to the vacuolar membrane (tonoplast). Therefore, growth effects cannot be linked to protein function without further evidence. Various potential causes are discussed, including inaccuracies in the genome resource used as reference for primer design and issues inherent to the model system. Finally, I make suggestions on how to proceed to further characterize the candidate genes and hopefully identify novel sodium transporters from barley.

  9. Human NKCC2 cation–Cl– co-transporter complements lack of Vhc1 transporter in yeast vacuolar membranes.

    Science.gov (United States)

    Petrezselyova, Silvia; Dominguez, Angel; Herynkova, Pavla; Macias, Juan F; Sychrova, Hana

    2013-10-01

    Cation–chloride co-transporters serve to transport Cl– and alkali metal cations. Whereas a large family of these exists in higher eukaryotes, yeasts only possess one cation–chloride co-transporter, Vhc1, localized to the vacuolar membrane. In this study, the human cation–chloride co-transporter NKCC2 complemented the phenotype of VHC1 deletion in Saccharomyces cerevisiae and its activity controlled the growth of salt-sensitive yeast cells in the presence of high KCl, NaCl and LiCl. A S. cerevisiae mutant lacking plasma-membrane alkali–metal cation exporters Nha1 and Ena1-5 and the vacuolar cation–chloride co-transporter Vhc1 is highly sensitive to increased concentrations of alkali–metal cations, and it proved to be a suitable model for characterizing the substrate specificity and transport activity of human wild-type and mutated cation–chloride co-transporters. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Characteristics of Sucrose Transport through the Sucrose-Specific Porin ScrY Studied by Molecular Dynamics Simulations

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    Liping eSun

    2016-02-01

    Full Text Available Sucrose-specific porin (ScrY is a transmembrane protein that allows for the uptake of sucrose under growth-limiting conditions. The crystal structure of ScrY was resolved before by X-ray crystallography, both in its uncomplexed form and with bound sucrose. However, little is known about the molecular characteristics of the transport mechanism of ScrY. To date, there has not yet been any clear demonstration for sucrose transport through the ScrY.Here, the dynamics of the ScrY trimer embedded in a phospholipid bilayer as well as the characteristics of sucrose translocation were investigated by means of atomistic molecular dynamics (MD simulations. The potential of mean force (PMF for sucrose translocation through the pore showed two main energy barriers within the constriction region of ScrY. Energy decomposition allowed to pinpoint three aspartic acids as key residues opposing the passage of sucrose, all located within the L3 loop. Mutation of two aspartic acids to uncharged residues resulted in an accordingly modified electrostatics and decreased PMF barrier. The chosen methodology and results will aid in the design of porins with modified transport specificities.

  11. Linking expression of fructan active enzymes, cell wall invertases and sucrose transporters with fructan profiles in growing taproot of chicory (Cichorium intybus: Impact of hormonal and environmental cues

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    Hongbin Wei

    2016-12-01

    Full Text Available In chicory taproot, the inulin-type fructans serve as carbohydrate reserve. Inulin metabolism is mediated by fructan active enzymes (FAZYs: sucrose:sucrose 1-fructosyltransferase (1-SST; fructan synthesis, fructan:fructan-1-fructosyltransferase (1-FFT; fructan synthesis and degradation, and fructan 1-exohydrolases (1-FEH1/2a/2b; fructan degradation. In developing taproot, fructan synthesis is affected by source-to-sink sucrose transport and sink unloading. In the present study, expression of FAZYs, sucrose transporter and CWI isoforms, vacuolar invertase and sucrose synthase was determined in leaf blade, petiole and taproot of young chicory plants (taproot diameter: 2cm and compared with taproot fructan profiles for the following scenarios: i N-starvation, ii abscisic acid (ABA treatment, iii ethylene treatment (via 1-aminoyclopropane-1-carboxylic acid [ACC], and iv cold treatment. Both N-starvation and ABA treatment induced an increase in taproot oligofructans. However, while under N-starvation this increase reflected de novo synthesis, under ABA treatment gene expression profiles indicated a role for both de novo synthesis and degradation of long-chain fructans. Conversely, under ACC and cold treatment oligofructans slightly decreased, correlating with reduced expression of 1-SST and 1-FFT and increased expression of FEHs and VI. Distinct SUT and CWI expression profiles were observed, indicating a functional alignment of SUT and CWI expression with taproot fructan metabolism under different source-sink scenarios.

  12. The vacuolar transport of aleurain-GFP and 2S albumin-GFP fusions is mediated by the same pre-vacuolar compartments in tobacco BY-2 and Arabidopsis suspension cultured cells.

    Science.gov (United States)

    Miao, Yansong; Li, Kwun Yee; Li, Hong-Ye; Yao, Xiaoqiang; Jiang, Liwen

    2008-12-01

    Soluble proteins reach vacuoles because they contain vacuolar sorting determinants (VSDs) that are recognized by vacuolar sorting receptor (VSR) proteins. Pre-vacuolar compartments (PVCs), defined by VSRs and GFP-VSR reporters in tobacco BY-2 cells, are membrane-bound intermediate organelles that mediate protein traffic from the Golgi apparatus to the vacuole in plant cells. Multiple pathways have been demonstrated to be responsible for vacuolar transport of lytic enzymes and storage proteins to the lytic vacuole (LV) and the protein storage vacuole (PSV), respectively. However, the nature of PVCs for LV and PSV pathways remains unclear. Here, we used two fluorescent reporters, aleurain-GFP and 2S albumin-GFP, that represent traffic of lytic enzymes and storage proteins to LV and PSV, respectively, to study the PVC-mediated transport pathways via transient expression in suspension cultured cells. We demonstrated that the vacuolar transport of aleurain-GFP and 2S albumin-GFP was mediated by the same PVC populations in both tobacco BY-2 and Arabidopsis suspension cultured cells. These PVCs were defined by the seven GFP-AtVSR reporters. In wortmannin-treated cells, the vacuolated PVCs contained the mRFP-AtVSR reporter in their limiting membranes, whereas the soluble aleurain-GFP or 2S albumin-GFP remained in the lumen of the PVCs, indicating a possible in vivo relationship between receptor and cargo within PVCs.

  13. Arg188 in rice sucrose transporter OsSUT1 is crucial for substrate transport

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    Sun Ye

    2012-11-01

    Full Text Available Abstract Background Plant sucrose uptake transporters (SUTs are H+/sucrose symporters related to the major facilitator superfamily (MFS. SUTs are essential for plant growth but little is known about their transport mechanism. Recent work identified several conserved, charged amino acids within transmembrane spans (TMS in SUTs that are essential for transport activity. Here we further evaluated the role of one of these positions, R188 in the fourth TMS of OsSUT1, a type II SUT. Results The OsSUT1(R188K mutant, studied by expression in plants, yeast, and Xenopus oocytes, did not transport sucrose but showed a H+ leak that was blocked by sucrose. The H+ leak was also blocked by β-phenyl glucoside which is not translocated by OsSUT1. Replacing the corresponding Arg in type I and type III SUTs, AtSUC1(R163K and LjSUT4(R169K, respectively, also resulted in loss of sucrose transport activity. Fluorination at the glucosyl 3 and 4 positions of α-phenyl glucoside greatly decreased transport by wild type OsSUT1 but did not affect the ability to block H+ leak in the R188K mutant. Conclusion OsSUT1 R188 appears to be essential for sucrose translocation but not for substrate interaction that blocks H+ leak. Therefore, we propose that an additional binding site functions in the initial recognition of substrates. The corresponding Arg in type I and III SUTs are equally important. We propose that R188 interacts with glucosyl 3-OH and 4-OH during translocation.

  14. Interactions between co-expressed Arabidopsis sucrose transporters in the split-ubiquitin system

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    Lalonde Sylvie

    2003-03-01

    Full Text Available Abstract Background The Arabidopsis genome contains nine sucrose transporter paralogs falling into three clades: SUT1-like, SUT2 and SUT4. The carriers differ in their kinetic properties. Many transport proteins are known to exist as oligomers. The yeast-based split ubiquitin system can be used to analyze the ability of membrane proteins to interact. Results Promoter-GUS fusions were used to analyze the cellular expression of the three transporter genes in transgenic Arabidopsis plants. All three fusion genes are co-expressed in companion cells. Protein-protein interactions between Arabidopsis sucrose transporters were tested using the split ubiquitin system. Three paralogous sucrose transporters are capable of interacting as either homo- or heteromers. The interactions are specific, since a potassium channel and a glucose transporter did not show interaction with sucrose transporters. Also the biosynthetic and metabolizing enzymes, sucrose phosphate phosphatase and sucrose synthase, which were found to be at least in part bound to the plasma membrane, did not specifically interact with sucrose transporters. Conclusions The split-ubiquitin system provides a powerful tool to detect potential interactions between plant membrane proteins by heterologous expression in yeast, and can be used to screen for interactions with membrane proteins as baits. Like other membrane proteins, the Arabidopsis sucrose transporters are able to form oligomers. The biochemical approaches are required to confirm the in planta interaction.

  15. Carbon source-sink relationship in Arabidopsis thaliana: the role of sucrose transporters.

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    Durand, Mickaël; Mainson, Dany; Porcheron, Benoît; Maurousset, Laurence; Lemoine, Rémi; Pourtau, Nathalie

    2018-03-01

    The regulation of source-to-sink sucrose transport is associated with AtSUC and AtSWEET sucrose transporters' gene expression changes in plants grown hydroponically under different physiological conditions. Source-to-sink transport of sucrose is one of the major determinants of plant growth. Whole-plant carbohydrates' partitioning requires the specific activity of membrane sugar transporters. In Arabidopsis thaliana plants, two families of transporters are involved in sucrose transport: AtSUCs and AtSWEETs. This study is focused on the comparison of sucrose transporter gene expression, soluble sugar and starch levels and long distance sucrose transport, in leaves and sink organs (mainly roots) in different physiological conditions (along the plant life cycle, during a diel cycle, and during an osmotic stress) in plants grown hydroponically. In leaves, the AtSUC2, AtSWEET11, and 12 genes known to be involved in phloem loading were highly expressed when sucrose export was high and reduced during osmotic stress. In roots, AtSUC1 was highly expressed and its expression profile in the different conditions tested suggests that it may play a role in sucrose unloading in roots and in root growth. The SWEET transporter genes AtSWEET12, 13, and 15 were found expressed in all organs at all stages studied, while differential expression was noticed for AtSWEET14 in roots, stems, and siliques and AtSWEET9, 10 expressions were only detected in stems and siliques. A role for these transporters in carbohydrate partitioning in different source-sink status is proposed, with a specific attention on carbon demand in roots. During development, despite trophic competition with others sinks, roots remained a significant sink, but during osmotic stress, the amount of translocated [U- 14 C]-sucrose decreased for rosettes and roots. Altogether, these results suggest that source-sink relationship may be linked with the regulation of sucrose transporter gene expression.

  16. Molecular cloning and expression analysis of turnip (Brassica rapa var. rapa sucrose transporter gene family

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    Yuanyuan Liu

    2017-06-01

    Full Text Available In higher plants, sugars (mainly sucrose are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and development. Sucrose transporters, or sucrose carriers (SUCs, play an important role in the long-distance transportation of sucrose from source organs to sink organs, thereby affecting crop yield and quality. The identification, characterization, and molecular function analysis of sucrose transporter genes have been reported for monocot and dicot plants. However, no relevant study has been reported on sucrose transporter genes in Brassica rapa var. rapa, a cruciferous root crop used mainly as vegetables and fodder. We identified and cloned 12 sucrose transporter genes from turnips, named BrrSUC1.1 to BrrSUC6.2 according to the SUC gene sequences of B. rapa pekinensis. We constructed a phylogenetic tree and analyzed conserved motifs for all 12 sucrose transporter genes identified. Real-time quantitative polymerase chain reaction was conducted to understand the expression levels of SUC genes in different tissues and developmental phases of the turnip. These findings add to our understanding of the genetics and physiology of sugar transport during taproot formation in turnips.

  17. Sucrose-Metabolizing Enzymes in Transport Tissues and Adjacent Sink Structures in Developing Citrus Fruit 1

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    Lowell, Cadance A.; Tomlinson, Patricia T.; Koch, Karen E.

    1989-01-01

    Juice tissues of citrus lack phloem; therefore, photosynthates enroute to juice sacs exit the vascular system on the surface of each segment. Areas of extensive phloem unloading and transport (vascular bundles + segment epidermis) can thus be separated from those of assimilate storage (juice sacs) and adjacent tissues where both processes occur (peel). Sugar composition, dry weight accumulation, and activities of four sucrose-metabolizing enzymes (soluble and cell-wall-bound acid invertase, alkaline invertase, sucrose synthase, and sucrose phosphate synthase) were measured in these transport and sink tissues of grapefruit (Citrus paradisi Macf.) to determine more clearly whether a given enzyme appeared to be more directly associated with assimilate transport versus deposition or utilization. Results were compared at three developmental stages. Activity of sucrose (per gram fresh weight and per milligram protein) extracted from zones of extensive phloem unloading and transport was significantly greater than from adjacent sink tissues during the stages (II and III) when juice sacs grow most rapidly. In stage II fruit, activity of sucrose synthase also significantly surpassed that of all other sucrose-metabolizing enzymes in extracts from the transport tissues (vascular bundles + segment epidermis). In contrast, sucrose phosphate synthase and alkaline invertase at this stage of growth were the most active enzymes from adjacent, rapidly growing, phloem-free sink tissues (juice sacs). Activity of these two enzymes in extracts from juice sacs was significantly greater than that form the transport tissues (vascular bundles + segment epidermis). Soluble acid invertase was the most active enzyme in extracts from all tissues of very young fruit (stage I), including nonvascular regions, but nearly disappeared prior to the onset of juice sac sugar accumulation. The physiological function of high sucrose synthase activity in the transport tissues during rapid sucrose import

  18. Vacuolar zinc transporter Zrc1 is required for detoxification of excess intracellular zinc in the human fungal pathogen Cryptococcus neoformans.

    Science.gov (United States)

    Cho, Minsu; Hu, Guanggan; Caza, Mélissa; Horianopoulos, Linda C; Kronstad, James W; Jung, Won Hee

    2018-01-01

    Zinc is an important transition metal in all living organisms and is required for numerous biological processes. However, excess zinc can also be toxic to cells and cause cellular stress. In the model fungus Saccharomyces cerevisiae, a vacuolar zinc transporter, Zrc1, plays important roles in the storage and detoxification of excess intracellular zinc to protect the cell. In this study, we identified an ortholog of the S. cerevisiae ZRC1 gene in the human fungal pathogen Cryptococcus neoformans. Zrc1 was localized in the vacuolar membrane in C. neoformans, and a mutant lacking ZRC1 showed significant growth defects under high-zinc conditions. These results suggested a role for Zrc1 in zinc detoxification. However, contrary to our expectation, the expression of Zrc1 was induced in cells grown in zinc-limited conditions and decreased upon the addition of zinc. These expression patterns were similar to those of Zip1, the high-affinity zinc transporter in the plasma membrane of C. neoformans. Furthermore, we used the zrc1 mutant in a murine model of cryptococcosis to examine whether a mammalian host could inhibit the survival of C. neoformans using zinc toxicity. We found that the mutant showed no difference in virulence compared with the wildtype strain. This result suggests that Zrc1-mediated zinc detoxification is not required for the virulence of C. neoformans, and imply that zinc toxicity may not be an important aspect of the host immune response to the fungus.

  19. Inverse pH regulation of plant and fungal sucrose transporters: a mechanism to regulate competition for sucrose at the host/pathogen interface?

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    Kathrin Wippel

    Full Text Available BACKGROUND: Plant sucrose transporter activities were shown to respond to changes in the extracellular pH and redox status, and oxidizing compounds like glutathione (GSSG or H(2O(2 were reported to effect the subcellular targeting of these proteins. We hypothesized that changes in both parameters might be used to modulate the activities of competing sucrose transporters at a plant/pathogen interface. We, therefore, compared the effects of redox-active compounds and of extracellular pH on the sucrose transporters UmSRT1 and ZmSUT1 known to compete for extracellular sucrose in the Ustilago maydis (corn smut/Zea mays (maize pathosystem. METHODOLOGY/PRINCIPAL FINDINGS: We present functional analyses of the U. maydis sucrose transporter UmSRT1 and of the plant sucrose transporters ZmSUT1 and StSUT1 in Saccharomyces cerevisiae or in Xenopus laevis oocytes in the presence of different extracellular pH-values and redox systems, and study the possible effects of these treatments on the subcellular targeting. We observed an inverse regulation of host and pathogen sucrose transporters by changes in the apoplastic pH. Under none of the conditions analyzed, we could confirm the reported effects of redox-active compounds. CONCLUSIONS/SIGNIFICANCE: Our data suggest that changes in the extracellular pH but not of the extracellular redox status might be used to oppositely adjust the transport activities of plant and fungal sucrose transporters at the host/pathogen interface.

  20. The Arabidopsis cax1 mutant exhibits impaired ion homeostasis, development, and hormonal responses and reveals interplay among vacuolar transporters.

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    Cheng, Ning-Hui; Pittman, Jon K; Barkla, Bronwyn J; Shigaki, Toshiro; Hirschi, Kendal D

    2003-02-01

    The Arabidopsis Ca(2+)/H(+) transporter CAX1 (Cation Exchanger1) may be an important regulator of intracellular Ca(2+) levels. Here, we describe the preliminary localization of CAX1 to the tonoplast and the molecular and biochemical characterization of cax1 mutants. We show that these mutants exhibit a 50% reduction in tonoplast Ca(2+)/H(+) antiport activity, a 40% reduction in tonoplast V-type H(+)-translocating ATPase activity, a 36% increase in tonoplast Ca(2+)-ATPase activity, and increased expression of the putative vacuolar Ca(2+)/H(+) antiporters CAX3 and CAX4. Enhanced growth was displayed by the cax1 lines under Mn(2+) and Mg(2+) stress conditions. The mutants exhibited altered plant development, perturbed hormone sensitivities, and altered expression of an auxin-regulated promoter-reporter gene fusion. We propose that CAX1 regulates myriad plant processes and discuss the observed phenotypes with regard to the compensatory alterations in other transporters.

  1. The Arabidopsis cax1 Mutant Exhibits Impaired Ion Homeostasis, Development, and Hormonal Responses and Reveals Interplay among Vacuolar Transporters

    Science.gov (United States)

    Cheng, Ning-Hui; Pittman, Jon K.; Barkla, Bronwyn J.; Shigaki, Toshiro; Hirschi, Kendal D.

    2003-01-01

    The Arabidopsis Ca2+/H+ transporter CAX1 (Cation Exchanger1) may be an important regulator of intracellular Ca2+ levels. Here, we describe the preliminary localization of CAX1 to the tonoplast and the molecular and biochemical characterization of cax1 mutants. We show that these mutants exhibit a 50% reduction in tonoplast Ca2+/H+ antiport activity, a 40% reduction in tonoplast V-type H+-translocating ATPase activity, a 36% increase in tonoplast Ca2+-ATPase activity, and increased expression of the putative vacuolar Ca2+/H+ antiporters CAX3 and CAX4. Enhanced growth was displayed by the cax1 lines under Mn2+ and Mg2+ stress conditions. The mutants exhibited altered plant development, perturbed hormone sensitivities, and altered expression of an auxin-regulated promoter-reporter gene fusion. We propose that CAX1 regulates myriad plant processes and discuss the observed phenotypes with regard to the compensatory alterations in other transporters. PMID:12566577

  2. Nectar secretion requires sucrose phosphate synthases and the sugar transporter SWEET9.

    Science.gov (United States)

    Lin, I Winnie; Sosso, Davide; Chen, Li-Qing; Gase, Klaus; Kim, Sang-Gyu; Kessler, Danny; Klinkenberg, Peter M; Gorder, Molly K; Hou, Bi-Huei; Qu, Xiao-Qing; Carter, Clay J; Baldwin, Ian T; Frommer, Wolf B

    2014-04-24

    Angiosperms developed floral nectaries that reward pollinating insects. Although nectar function and composition have been characterized, the mechanism of nectar secretion has remained unclear. Here we identify SWEET9 as a nectary-specific sugar transporter in three eudicot species: Arabidopsis thaliana, Brassica rapa (extrastaminal nectaries) and Nicotiana attenuata (gynoecial nectaries). We show that SWEET9 is essential for nectar production and can function as an efflux transporter. We also show that sucrose phosphate synthase genes, encoding key enzymes for sucrose biosynthesis, are highly expressed in nectaries and that their expression is also essential for nectar secretion. Together these data are consistent with a model in which sucrose is synthesized in the nectary parenchyma and subsequently secreted into the extracellular space via SWEET9, where sucrose is hydrolysed by an apoplasmic invertase to produce a mixture of sucrose, glucose and fructose. The recruitment of SWEET9 for sucrose export may have been a key innovation, and could have coincided with the evolution of core eudicots and contributed to the evolution of nectar secretion to reward pollinators.

  3. [Function of transport H+-ATPases in plant cell plasma and vacuolar membranes of maize under salt stress conditions and effect of adaptogenic preparations].

    Science.gov (United States)

    Rybchenko, Zh I; Palladina, T O

    2011-01-01

    Participations of electrogenic H+-pumps of plasma and vacuolar membranes represented by E1-E2 and V-type H+-ATPases in plant cell adaptation to salt stress conditions has been studied by determination of their transport activities. Experiments were carried out on corn seedlings exposed during 1 or 10 days at 0.1 M NaCl. Preparations Methyure and Ivine were used by seed soaking at 10(-7) M. Plasma and vacuolar membrane fractions were isolated from corn seedling roots. In variants without NaCl a hydrolytical activity of plasma membrane H+-ATPase was increased with seedling age and its transport one was changed insignificantly, wherease the response of the weaker vacuolar H+-ATPase was opposite. NaCl exposition decreased hydrolytical activities of both H+-ATPases and increased their transport ones. These results demonstrated amplification of H+-pumps function especially represented by vacuolar H+-ATPase. Both preparations, Methyure mainly, caused a further increase of transport activity which was more expressed in NaCl variants. Obtained results showed the important role of these H+-pumps in plant adaptation under salt stress conditions realized by energetical maintenance of the secondary active Na+/H+ -antiporters which remove Na+ from cytoplasm.

  4. A vacuolar iron transporter in tulip, TgVit1, is responsible for blue coloration in petal cells through iron accumulation.

    Science.gov (United States)

    Momonoi, Kazumi; Yoshida, Kumi; Mano, Shoji; Takahashi, Hideyuki; Nakamori, Chihiro; Shoji, Kazuaki; Nitta, Akira; Nishimura, Mikio

    2009-08-01

    Blue color in flowers is due mainly to anthocyanins, and a considerable part of blue coloration can be attributed to metal-complexed anthocyanins. However, the mechanism of metal ion transport into vacuoles and subsequent flower color development has yet to be fully explored. Previously, we studied the mechanism of blue color development specifically at the bottom of the inner perianth in purple tulip petals of Tulipa gesneriana cv. Murasakizuisho. We found that differences in iron content were associated with the development of blue- and purple-colored cells. Here, we identify a vacuolar iron transporter in T. gesneriana (TgVit1), and characterize the localization and function of this transporter protein in tulip petals. The amino acid sequence of TgVit1 is 85% similar that of the Arabidopsis thaliana vacuolar iron transporter AtVIT1, and also showed similarity to the AtVIT1 homolog in yeast, Ca(2+)-sensitive cross-complementer 1 (CCC1). The gene TgVit1 was expressed exclusively in blue-colored epidermal cells, and protein levels increased with increasing mRNA expression and blue coloration. Transient expression experiments revealed that TgVit1 localizes to the vacuolar membrane, and is responsible for the development of the blue color in purple cells. Expression of TgVit1 in yeast rescued the growth defect of ccc1 mutant cells in the presence of high concentrations of FeSO(4). Our results indicate that TgVit1 plays an essential role in blue coloration as a vacuolar iron transporter in tulip petals. These results suggest a new role for involvement of a vacuolar iron transporter in blue flower color development.

  5. Dissection of autophagy in tobacco BY-2 cells under sucrose starvation conditions using the vacuolar H(+)-ATPase inhibitor concanamycin A and the autophagy-related protein Atg8.

    Science.gov (United States)

    Yano, Kanako; Yanagisawa, Takahiro; Mukae, Kyosuke; Niwa, Yasuo; Inoue, Yuko; Moriyasu, Yuji

    2015-01-01

    Tobacco BY-2 cells undergo autophagy in sucrose-free culture medium, which is the process mostly responsible for intracellular protein degradation under these conditions. Autophagy was inhibited by the vacuolar H(+)-ATPase inhibitors concanamycin A and bafilomycin A1, which caused the accumulation of autophagic bodies in the central vacuoles. Such accumulation did not occur in the presence of the autophagy inhibitor 3-methyladenine, and concanamycin in turn inhibited the accumulation of autolysosomes in the presence of the cysteine protease inhibitor E-64c. Electron microscopy revealed not only that the autophagic bodies were accumulated in the central vacuole, but also that autophagosome-like structures were more frequently observed in the cytoplasm in treatments with concanamycin, suggesting that concanamycin affects the morphology of autophagosomes in addition to raising the pH of the central vacuole. Using BY-2 cells that constitutively express a fusion protein of autophagosome marker protein Atg8 and green fluorescent protein (GFP), we observed the appearance of autophagosomes by fluorescence microscopy, which is a reliable morphological marker of autophagy, and the processing of the fusion protein to GFP, which is a biochemical marker of autophagy. Together, these results suggest the involvement of vacuole type H(+)-ATPase in the maturation step of autophagosomes to autolysosomes in the autophagic process of BY-2 cells. The accumulation of autophagic bodies in the central vacuole by concanamycin is a marker of the occurrence of autophagy; however, it does not necessarily mean that the central vacuole is the site of cytoplasm degradation.

  6. Plasmodium falciparum chloroquine resistance transporter (PfCRT) isoforms PH1 and PH2 perturb vacuolar physiology.

    Science.gov (United States)

    Callaghan, Paul S; Siriwardana, Amila; Hassett, Matthew R; Roepe, Paul D

    2016-03-31

    Recent work has perfected yeast-based methods for measuring drug transport by the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT). The approach relies on inducible heterologous expression of PfCRT in Saccharomyces cerevisiae yeast. In these experiments selecting drug concentrations are not toxic to the yeast, nor is expression of PfCRT alone toxic. Only when PfCRT is expressed in the presence of CQ is the growth of yeast impaired, due to inward transport of chloroquine (CQ) via the transporter. During analysis of all 53 known naturally occurring PfCRT isoforms, two isoforms (PH1 and PH2 PfCRT) were found to be intrinsically toxic to yeast, even in the absence of CQ. Additional analysis of six very recently identified PfCRT isoforms from Malaysia also showed some toxicity. In this paper the nature of this yeast toxicity is examined. Data also show that PH1 and PH2 isoforms of PfCRT transport CQ with an efficiency intermediate to that catalyzed by previously studied CQR conferring isoforms. Mutation of PfCRT at position 160 is found to perturb vacuolar physiology, suggesting a fitness cost to position 160 amino acid substitutions. These data further define the wide range of activities that exist for PfCRT isoforms found in P. falciparum isolates from around the globe.

  7. Sucrose transport and phloem unloading in stem of Vicia faba: possible involvement of a sucrose carrier and osmotic regulation

    International Nuclear Information System (INIS)

    Aloni, B.; Wyse, R.E.; Griffith, S.

    1986-01-01

    After pulse labeling of a source leaf with 14 CO 2 , stem sections of Vicia faba plants were cut and the efflux characteristics of 14 C-labeled sugars into various buffered solutions were determined. Radiolabeled sucrose was shown to remain localized in the phloem and adjacent phloem parenchyma tissues after a 2-hour chase. Therefore, sucrose leakage from stem segments prepared following a 75-minute chase period was assumed to be characteristic of phloem unloading. The efflux of 14 C assimilates from the phloem was enhanced by 1 millimolar p-chloromercuribenzene sulfonic acid (PCMBS) and by 5 micromolar carbonyl cyanide m-chlorophenly hydrazone (CCCP). However, PCMBS inhibited and CCCP enhanced general leakage of nonradioactive sugars from the stem segments. Sucrose at concentrations of 50 millimolar in the free space increased efflux of [ 14 C]sucrose, presumably through an exchange mechanism. This exchange was inhibited by PCMBS and abolished by 0.2 molar mannitol. Increasing the osmotic concentration of the efflux medium with mannitol reduced [ 14 C]sucrose efflux. However, this inhibition seems not to be specific to sucrose unloading since leakage of total sugars, nonlabeled sucrose, glucose, and amino acids from the bulk of the tissue was reduced in a similar manner. The data suggest that phloem unloading in cut stem segments is consistent with passive efflux of sucrose from the phloem to the apoplast and that sucrose exchange via a membrane carrier may be involved

  8. SUT sucrose and MST monosaccharide transporter inventory of the Selaginella genome

    Directory of Open Access Journals (Sweden)

    Sylvie eLalonde

    2012-02-01

    Full Text Available While most metazoa mainly use hexose transporters to acquire hexoses from their diet and as a transport form for distributing carbon and energy within their bodies, insects use trehalose and plants use sucrose as their major form for translocation. Plant genomes contain at least three families of mono- and disaccharide transporters: monosaccharide/polyol transporters that are evolutionary closely related to the yeast and human glucose transporters, sucrose transporters of the SUT family, which similar to the hexose transporters belong to the major facilitator superfamily (MFS, but share only minimal amino acid sequence homology to the hexose transporters, and the family of SWEET sugar transporters conserved between animals and plants. Recently, the genome sequence of the spikemoss Selaginella has been determined. In order to study the evolution of sugar transport in plants, we carried out a careful annotation of the complement of sugar transporters in Selaginella. We review what is known about sugar transport in spikemoss and provide phylogenetic analyses of the complement of MST and SUT homologs in Selaginella.

  9. Dissection of autophagy in tobacco BY-2 cells under sucrose starvation conditions using the vacuolar H+-ATPase inhibitor concanamycin A and the autophagy-related protein Atg8

    Science.gov (United States)

    Yano, Kanako; Yanagisawa, Takahiro; Mukae, Kyosuke; Niwa, Yasuo; Inoue, Yuko; Moriyasu, Yuji

    2015-01-01

    Tobacco BY-2 cells undergo autophagy in sucrose-free culture medium, which is the process mostly responsible for intracellular protein degradation under these conditions. Autophagy was inhibited by the vacuolar H+-ATPase inhibitors concanamycin A and bafilomycin A1, which caused the accumulation of autophagic bodies in the central vacuoles. Such accumulation did not occur in the presence of the autophagy inhibitor 3-methyladenine, and concanamycin in turn inhibited the accumulation of autolysosomes in the presence of the cysteine protease inhibitor E-64c. Electron microscopy revealed not only that the autophagic bodies were accumulated in the central vacuole, but also that autophagosome-like structures were more frequently observed in the cytoplasm in treatments with concanamycin, suggesting that concanamycin affects the morphology of autophagosomes in addition to raising the pH of the central vacuole. Using BY-2 cells that constitutively express a fusion protein of autophagosome marker protein Atg8 and green fluorescent protein (GFP), we observed the appearance of autophagosomes by fluorescence microscopy, which is a reliable morphological marker of autophagy, and the processing of the fusion protein to GFP, which is a biochemical marker of autophagy. Together, these results suggest the involvement of vacuole type H+-ATPase in the maturation step of autophagosomes to autolysosomes in the autophagic process of BY-2 cells. The accumulation of autophagic bodies in the central vacuole by concanamycin is a marker of the occurrence of autophagy; however, it does not necessarily mean that the central vacuole is the site of cytoplasm degradation. PMID:26368310

  10. Partitioning and transport of the translocates mannitol and sucrose in the light and dark in celery (Apium Graveolens L. )

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.M.; Loescher, W.H.

    1987-04-01

    Sucrose and mannitol are major photosynthetic products and translocates in celery. Assimilate partitioning and transport were studied by pulse-labeling leaves with /sup 14/CO/sub 2/ followed by different length chases in ambient air. After a 2 h chase in the light there was more /sup 14/C in sucrose than mannitol in source leaves and their petioles. In contrast after a 2 h dark chase leaves contained more /sup 14/C in mannitol than sucrose but petioles had more /sup 14/C in sucrose than mannitol. After a 15 h chase (6 h light; 9 h dark) labeled sucrose was higher in source petiole vascular bundles than in adjacent parenchyma tissue but label in glucose and fructose was higher in the parenchyma tissue. After the 15 h chase most of the /sup 14/C remaining in developing sink leaves and their petioles was in mannitol. Although in the light mannitol:sucrose ratios are the same in leaf and petiole tissues, in the dark sucrose is initially the major translocate with mannitol becoming more important as leaf sucrose pools are depleted. When synthesized, sucrose is rapidly transported and then metabolized to hexose sugars whereas mannitol is used both for transport and storage.

  11. Overexpression of a Grapevine Sucrose Transporter (VvSUC27 in Tobacco Improves Plant Growth Rate in the Presence of Sucrose In vitro

    Directory of Open Access Journals (Sweden)

    Yumeng Cai

    2017-06-01

    Full Text Available The import of sugar from source leaves and it further accumulation in grape berries are considerably high during ripening, and this process is mediated via sucrose transporters. In this study, a grape sucrose transporter (SUT gene, VvSUC27, located at the plasma membrane, was transferred to tobacco (Nicotiana tabacum. The transformants were more sensitive to sucrose and showed more rapid development, especially roots, when cultured on MS agar medium containing sucrose, considering that the shoot/root dry weight ratio was only half that of the control. Moreover, all transformed plants exhibited light-colored leaves throughout their development, which indicated chlorosis and an associated reduction in photosynthesis. The total sugar content in the roots and stems of transformants was higher than that in control plants. No significant difference was observed in the leaves between the transformants and control plants. The levels of growth-promoting hormones were increased, and those of stress-mediating hormones were reduced in transgenic tobacco plants. The qRT-PCR analysis revealed that the expression of VvSUC27 was 1,000 times higher than that of the autologous tobacco sucrose transporter, which suggested that the markedly increased growth rate of transformants was because of the heterogeneously expressed gene. The transgenic tobacco plants showed resistance to abiotic stresses. Strikingly, the overexpression of VvSUC27 leaded to the up regulation of most reactive oxygen species scavengers and abscisic acid-related genes that might enable transgenic plants to overcome abiotic stress. Taken together, these results revealed an important role of VvSUC27 in plant growth and response to abiotic stresses, especially in the presence of sucrose in vitro.

  12. Stress regulated members of the plant organic cation transporter family are localized to the vacuolar membrane

    Directory of Open Access Journals (Sweden)

    Koch Wolfgang

    2008-07-01

    Full Text Available Abstract Background In Arabidopsis six genes group into the gene family of the organic cation transporters (OCTs. In animals the members of the OCT-family are mostly characterized as polyspecific transporters involved in the homeostasis of solutes, the transport of monoamine neurotransmitters and the transport of choline and carnitine. In plants little is known about function, localisation and regulation of this gene family. Only one protein has been characterized as a carnitine transporter at the plasma membrane so far. Findings We localized the five uncharacterized members of the Arabidopsis OCT family, designated OCT2-OCT6, via GFP fusions and protoplast transformation to the tonoplast. Expression analysis with RNA Gel Blots showed a distinct, organ-specific expression pattern of the individual genes. With reporter gene fusion of four members we analyzed the tissue specific distribution of OCT2, 3, 4, and 6. In experiments with salt, drought and cold stress, we could show that AtOCT4, 5 and 6 are up-regulated during drought stress, AtOCT3 and 5 during cold stress and AtOCT 5 and 6 during salt stress treatments. Conclusion Localisation of the proteins at the tonoplast and regulation of the gene expression under stress conditions suggests a specific role for the transporters in plant adaptation to environmental stress.

  13. ISOLASI cDNA SUCROSE TRANSPORTER (SUT DARI BATANG TANAMAN TEBU (Saccharum officinarum L.

    Directory of Open Access Journals (Sweden)

    - Slameto

    2010-09-01

    Full Text Available Sucrose Transporter (SUT is kind of protein transporter that control in sucrose translocation. Sucrose Transporter is intermediate in translocation of sucrose from apoplasmic to simplasmic. SUT facilitates sucrose transportation from vascular tissues to parenchyma cells toward in node sugarcane stem. This research was purposed to isolate cDNA SUT from sugarcane stem, and cloned in Escherichia coli strain DH5α. Total RNA of sugarcane stem was isolated by single step method, then add with oligo dT in order to obtain the first strand of SUT cDNA then used as template for PCR. The primer used for PCR is 5’ –ggg ctg att gtg gcc atg tc- ‘3 (SUT-F and 5’ –tgc cct ttg tct ccg gaa cc- ‘3 (SUT-R. PCR was programmed as follow denaturation at 94°C for 2 minutes and 30 second, annealing at 54°C for 30 s, extension at 72°C 2 min and 7 min, and storage at 4°C for unlimited, It was for 30 cycles. Complementary DNA SUT from PCR ligalized to pTOPO bunt-end, then it cloned in to E. coli strain DH5α. The cloning resulted then be sequenced in order to observe the homologues with other nucleotides sequences of some plant using BLASTn program in GENE BANK NCBI and the level of homology determined by Genetyx program. The concentrated of total RNA isolated was 5,024 μg/μl, with purity of 1,85. Complementary DNA SUT fragment from PCR with size 2037 bp appropriated to the both of primer was used. Complementary DNA SUT fragment showed by analyzed some of restriction enzyme e.g. EcoRI, PstI and BamHI. Homologues of this cDNA SUT fragment was 100% to SoSUT 2A of sugarcane stem and 84% to OsSUT of rice plant (Casu et al ., 2003.

  14. Characterization of Gene Candidates for Vacuolar Sodium Transport from Hordeum Vulgare

    KAUST Repository

    Scheu, Arne Hagen August

    2017-01-01

    Various potential causes are discussed, including inaccuracies in the genome resource used as reference for primer design and issues inherent to the model system. Finally, I make suggestions on how to proceed to further characterize the candidate genes and hopefully identify novel sodium transporters from barley.

  15. SUCROSE TRANSPORTER 5 supplies Arabidopsis embryos with biotin and affects triacylglycerol accumulation

    Science.gov (United States)

    Pommerrenig, Benjamin; Popko, Jennifer; Heilmann, Mareike; Schulmeister, Sylwia; Dietel, Katharina; Schmitt, Bianca; Stadler, Ruth; Feussner, Ivo; Sauer, Norbert

    2013-01-01

    The Arabidopsis SUC5 protein represents a classical sucrose/H+ symporter. Functional analyses previously revealed that SUC5 also transports biotin, an essential co-factor for fatty acid synthesis. However, evidence for a dual role in transport of the structurally unrelated compounds sucrose and biotin in plants was lacking. Here we show that SUC5 localizes to the plasma membrane, and that the SUC5 gene is expressed in developing embryos, confirming the role of the SUC5 protein as substrate carrier across apoplastic barriers in seeds. We show that transport of biotin but not of sucrose across these barriers is impaired in suc5 mutant embryos. In addition, we show that SUC5 is essential for the delivery of biotin into the embryo of biotin biosynthesis-defective mutants (bio1 and bio2). We compared embryo and seedling development as well as triacylglycerol accumulation and fatty acid composition in seeds of single mutants (suc5, bio1 or bio2), double mutants (suc5 bio1 and suc5 bio2) and wild-type plants. Although suc5 mutants were like the wild-type, bio1 and bio2 mutants showed developmental defects and reduced triacylglycerol contents. In suc5 bio1 and suc5 bio2 double mutants, developmental defects were severely increased and the triacylglycerol content was reduced to a greater extent in comparison to the single mutants. Supplementation with externally applied biotin helped to reduce symptoms in both single and double mutants, but the efficacy of supplementation was significantly lower in double than in single mutants, showing that transport of biotin into the embryo is lower in the absence of SUC5. PMID:23031218

  16. Transport and metabolism of a sucrose analog (1'-fluorosucrose) into Zea mays L. Endosperm without invertase hydrolysis

    International Nuclear Information System (INIS)

    Schmalstig, J.G.; Hitz, W.D.

    1987-01-01

    1'-fluorosucrose (FS), a sucrose analog resistant to hydrolysis by invertase, was transported from husk leaves into maize (Zea mays L.) kernels with the same magnitude and kinetics as sucrose. 14 C-Label from [ 14 C]FS and [ 14 C]sucrose in separate experiments was distributed similarly between the pedicel, endosperm, and embryo with time. FS passed through maternal tissue and was adsorbed intact into the endosperm where it was metabolized and used in synthesis of sucrose and methanol-chloroform-water insolubles. Accumulation of [ 14 C]sucrose from supplied [ 14 C]glucosyl-FS indicated that the glucose moiety from the breakdown of sucrose (here FS), which normally occurs in the process of starch synthesis in maize endosperm, was available to the pool of substrates for resynthesis of sucrose. Uptake of FS into maize endosperm without hydrolysis suggest that despite the presence of invertase in maternal tissues and the hydrolysis of a large percentage of sucrose unloaded form the phloem, hexoses are not specifically needed for uptake into maize endosperm

  17. Yeast carboxypeptidase Y requires glycosylation for efficient intracellular transport, but not for vacuolar sorting, in vivo stability, or activity

    DEFF Research Database (Denmark)

    Winther, Jakob R.; Stevens, T H; Kielland-Brandt, Morten

    1991-01-01

    Functions of the carbohydrate side chains of the yeast vacuolar enzyme carboxypeptidase Y (CPY) were investigated by removal, through site-directed mutagenesis, of the sequences which act as signals for N-linked glycosylation. The mutant forms of the enzyme were analysed with respect to activity...

  18. Aspen SUCROSE TRANSPORTER3 Allocates Carbon into Wood Fibers1[C][W

    Science.gov (United States)

    Mahboubi, Amir; Ratke, Christine; Gorzsás, András; Kumar, Manoj; Mellerowicz, Ewa J.; Niittylä, Totte

    2013-01-01

    Wood formation in trees requires carbon import from the photosynthetic tissues. In several tree species, including Populus species, the majority of this carbon is derived from sucrose (Suc) transported in the phloem. The mechanism of radial Suc transport from phloem to developing wood is not well understood. We investigated the role of active Suc transport during secondary cell wall formation in hybrid aspen (Populus tremula × Populus tremuloides). We show that RNA interference-mediated reduction of PttSUT3 (for Suc/H+ symporter) during secondary cell wall formation in developing wood caused thinner wood fiber walls accompanied by a reduction in cellulose and an increase in lignin. Suc content in the phloem and developing wood was not significantly changed. However, after 13CO2 assimilation, the SUT3RNAi lines contained more 13C than the wild type in the Suc-containing extract of developing wood. Hence, Suc was transported into developing wood, but the Suc-derived carbon was not efficiently incorporated to wood fiber walls. A yellow fluorescent protein:PttSUT3 fusion localized to plasma membrane, suggesting that reduced Suc import into developing wood fibers was the cause of the observed cell wall phenotype. The results show the importance of active Suc transport for wood formation in a symplasmically phloem-loading tree species and identify PttSUT3 as a principal transporter for carbon delivery into secondary cell wall-forming wood fibers. PMID:24170204

  19. Molecular cloning and expression analysis of the sucrose transporter gene family from Theobroma cacao L.

    Science.gov (United States)

    Li, Fupeng; Wu, Baoduo; Qin, Xiaowei; Yan, Lin; Hao, Chaoyun; Tan, Lehe; Lai, Jianxiong

    2014-08-10

    In this study, we performed cloning and expression analysis of six putative sucrose transporter genes, designated TcSUT1, TcSUT2, TcSUT3, TcSUT4, TcSUT5 and TcSUT6, from the cacao genotype 'TAS-R8'. The combination of cDNA and genomic DNA sequences revealed that the cacao SUT genes contained exon numbers ranging from 1 to 14. The average molecular mass of all six deduced proteins was approximately 56 kDa (range 52 to 66 kDa). All six proteins were predicted to exhibit typical features of sucrose transporters with 12 trans-membrane spanning domains. Phylogenetic analysis revealed that TcSUT2 and TcSUT4 belonged to Group 2 SUT and Group 4 SUT, respectively, and the other TcSUT proteins were belonging to Group 1 SUT. Real-time PCR was conducted to investigate the expression pattern of each member of the SUT family in cacao. Our experiment showed that TcSUT1 was expressed dominantly in pods and that, TcSUT3 and TcSUT4 were highly expressed in both pods and in bark with phloem. Within pods, TcSUT1 and TcSUT4 were expressed more in the seed coat and seed from the pod enlargement stage to the ripening stage. TcSUT5 expression sharply increased to its highest expression level in the seed coat during the ripening stage. Expression pattern analysis indicated that TcSUT genes may be associated with photoassimilate transport into developing seeds and may, therefore, have an impact on seed production. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Potassium co-transport and antiport during the uptake of sucrose and glutamic acid from the xylem vessels

    NARCIS (Netherlands)

    Bel, A.J.E. van; Erven, A.J. van

    Perfusion experiments with excised internodes of tomato (Lycopersicon esculentum cv Moneymaker) showed that the uptake of glutamic acid and sucrose from the xylem vessels is accompanied with coupled proton co-transport and potassium antiport at low pH (<5.5). At high pH (5.5) both proton and

  1. Impaired phloem loading in zmsweet13a,b,c sucrose transporter triple knock-out mutants in Zea mays.

    Science.gov (United States)

    Bezrutczyk, Margaret; Hartwig, Thomas; Horschman, Marc; Char, Si Nian; Yang, Jinliang; Yang, Bing; Frommer, Wolf B; Sosso, Davide

    2018-04-01

    Crop yield depends on efficient allocation of sucrose from leaves to seeds. In Arabidopsis, phloem loading is mediated by a combination of SWEET sucrose effluxers and subsequent uptake by SUT1/SUC2 sucrose/H + symporters. ZmSUT1 is essential for carbon allocation in maize, but the relative contribution to apoplasmic phloem loading and retrieval of sucrose leaking from the translocation path is not known. Here we analysed the contribution of SWEETs to phloem loading in maize. We identified three leaf-expressed SWEET sucrose transporters as key components of apoplasmic phloem loading in Zea mays L. ZmSWEET13 paralogues (a, b, c) are among the most highly expressed genes in the leaf vasculature. Genome-edited triple knock-out mutants were severely stunted. Photosynthesis of mutants was impaired and leaves accumulated high levels of soluble sugars and starch. RNA-seq revealed profound transcriptional deregulation of genes associated with photosynthesis and carbohydrate metabolism. Genome-wide association study (GWAS) analyses may indicate that variability in ZmSWEET13s correlates with agronomical traits, especifically flowering time and leaf angle. This work provides support for cooperation of three ZmSWEET13s with ZmSUT1 in phloem loading in Z. mays. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  2. Dimerization and endocytosis of the sucrose transporter StSUT1 in mature sieve elements.

    Science.gov (United States)

    Liesche, Johannes; Schulz, Alexander; Krügel, Undine; Grimm, Bernhard; Kühn, Christina

    2008-12-01

    The sucrose transporter StSUT1 from Solanum tuberosum was shown to be regulated post-translationally by redox reagents. Its activity is increased at least 10-fold in the presence of oxidizing agents if expressed in yeast. Oxidation has also an effect on plasma membrane targeting and dimerization of the protein. In response to oxidizing agents, StSUT1 is targeted to lipid raft-like microdomains and SUT1 protein is detectable in the detergent resistant membrane fraction of plant plasma membranes. Interestingly, StSUT1 treated with brefeldin A seems to aggregate in endocytic compartments in mature sieve elements.1 Further analysis of SUT1 targeting will certainly provide more information about the putative involvement of lipid raft-like microdomains in endocytic events. We provide here additional information on the dimerization and endocytosis of the SUT1 protein. The oligomerization of overexpressed SoSUT1 from Spinacia oleracea in transgenic potato plants was analyzed by two-dimensional gel electrophoresis and endocytosis of the StSUT1 protein was confirmed by immunogold labeling.

  3. Organ and Tissue-specific Sucrose Transporters. Important Hubs in Gene and Metabolite Networks Regulating Carbon Use in Wood-forming Tissues of Populus

    Energy Technology Data Exchange (ETDEWEB)

    Harding, Scott A. [Univ. of Georgia, Athens, GA (United States); Tsai, Chung-Jui [Univ. of Georgia, Athens, GA (United States)

    2016-01-04

    The overall project objective was to probe the relationship between sucrose transporters and plant productivity in the biomass for biofuels woody perennial, Populus. At the time the proposal was written, sucrose transporters had already been investigated in many plant model systems, primarily with respect to the export of photosynthate sucrose from source leaves, and the uptake of sucrose in storage organs and seeds. Preliminary findings by the PI found that in Populus, sucrose transporter genes (SUTs) were well expressed in wood-forming tissues that comprise the feedstock for biofuels production. Because sucrose comprises by far the predominant form in which photosynthate is delivered from source organs to sink organs like roots and wood-forming tissues, SUTs control a gate that nominally at least could impact the allocation or partitioning of sucrose for potentially competing end uses like growth (stem biomass) and storage. In addition, water use might be conditioned by the way in which sucrose is distributed throughout the plant, and/or by the way in which sucrose is partitioned intracellularly. Several dozen transgenic lines were produced in year 1 of the project to perturb the expression ratio of multiple plasma membrane (PM) SUTs (intercellular trafficking), versus the single tonoplast membrane (TM) sucrose transporter that effectively regulates intracellular trafficking of sucrose. It was possible to obtain transgenic lines with dual SUT gene knockdown using the 35S promoter, but not the wood-specific TUA1 promoter. By the end of project year 2, a decision was made to work with the 35S plants while archiving the TUA1 plants. The PhD candidate charged with producing the transgenic lines abandoned the project during its second year, substantially contributing to the decision to operate with just the 35S lines. That student’s interests ranged more toward evolutionary topics, and a report on SUT gene evolution was published (Peng et al 2014).

  4. A novel high-affinity sucrose transporter is required for virulence of the plant pathogen Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Ramon Wahl

    2010-02-01

    Full Text Available Plant pathogenic fungi cause massive yield losses and affect both quality and safety of food and feed produced from infected plants. The main objective of plant pathogenic fungi is to get access to the organic carbon sources of their carbon-autotrophic hosts. However, the chemical nature of the carbon source(s and the mode of uptake are largely unknown. Here, we present a novel, plasma membrane-localized sucrose transporter (Srt1 from the corn smut fungus Ustilago maydis and its characterization as a fungal virulence factor. Srt1 has an unusually high substrate affinity, is absolutely sucrose specific, and allows the direct utilization of sucrose at the plant/fungal interface without extracellular hydrolysis and, thus, without the production of extracellular monosaccharides known to elicit plant immune responses. srt1 is expressed exclusively during infection, and its deletion strongly reduces fungal virulence. This emphasizes the central role of this protein both for efficient carbon supply and for avoidance of apoplastic signals potentially recognized by the host.

  5. Yeast carboxypeptidase Y requires glycosylation for efficient intracellular transport, but not for vacuolar sorting, in vivo stability, or activity

    DEFF Research Database (Denmark)

    Winther, Jakob R.; Stevens, T H; Kielland-Brandt, Morten

    1991-01-01

    the formation of asparagine-linked glycosylation, had a similar effect on the transport of CPY at 23 degrees C. However, the absence of N-linked carbohydrate in general had the more dramatic result of blocking the transport of CPY altogether at an increased temperature (37 degrees C). The unglycosylated mutant...

  6. Plasmodium falciparum chloroquine resistance transporter (PfCRT) isoforms PH1 and PH2 perturb vacuolar physiology

    OpenAIRE

    Callaghan, Paul S.; Siriwardana, Amila; Hassett, Matthew R.; Roepe, Paul D.

    2016-01-01

    Background Recent work has perfected yeast-based methods for measuring drug transport by the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT). Methods The approach relies on inducible heterologous expression of PfCRT in Saccharomyces cerevisiae yeast. In these experiments selecting drug concentrations are not toxic to the yeast, nor is expression of PfCRT alone toxic. Only when PfCRT is expressed in the presence of CQ is the growth of yeast impaired, due to inward transpo...

  7. Alternative expression of vacuolar iron transporter and ferritin genes leads to blue/purple coloration of flowers in tulip cv. 'Murasakizuisho'.

    Science.gov (United States)

    Shoji, Kazuaki; Momonoi, Kazumi; Tsuji, Tosiaki

    2010-02-01

    Flowers of tulip cv. 'Murasakizuisho' have a purple perianth except for the bottom region, which is blue in color even though it has the same anthocyanin, delphinidin 3-O-rutinoside, as the entire perianth. The development of the blue coloration in the perianth bottom is due to complexation by anthocyanin, flavonol and iron (Fe), as well as a vacuolar iron transporter, TgVit1. Although transient expression of TgVit1 in the purple cells led to a color change to light blue, the coloration of the transformed cells did not coincide with the dark blue color of the cells of the perianth bottom. We thought that another factor is required for the blue coloration of the cells of perianth bottom. To examine the effect of ferritin (FER), an Fe storage protein, on blue color development, we cloned an FER gene (TgFER1) and performed expression analyses. TgFER1 transcripts were found in the cells located in the upper region of the petals along with purple color development by anthocyanin and were not found in the blue cells of the perianth bottom. This gene expression is in contrast to that of TgVit1, expressed only in the cells of the perianth bottom. Co-expression of TgVIT1 and TgFER-RNAi, constructed for suppressing endogenous TgFER1 by RNA interference (RNAi), changed the purple petal cells to a dark blue color similar to that of the natural perianth bottom. These results strongly suggest that TgVit1 expression and TgFER1 suppression are critical for the development of blue color in the perianth bottom.

  8. Specific expression of the vacuolar iron transporter, TgVit, causes iron accumulation in blue-colored inner bottom segments of various tulip petals.

    Science.gov (United States)

    Momonoi, Kazumi; Tsuji, Toshiaki; Kazuma, Kohei; Yoshida, Kumi

    2012-01-01

    Several flowers of Tulipa gesneriana exhibit a blue color in the bottom segments of the inner perianth. We have previously reported the inner-bottom tissue-specific iron accumulation and expression of the vacuolar iron transporter, TgVit1, in tulip cv. Murasakizuisho. To clarify whether the TgVit1-dependent iron accumulation and blue-color development in tulip petals are universal, we analyzed anthocyanin, its co-pigment components, iron contents and the expression of TgVit1 mRNA in 13 cultivars which show a blue color in the bottom segments of the inner perianth accompanying yellow- and white-colored inner-bottom petals. All of the blue bottom segments contained the same anthocyanin component, delphinidin 3-rutinoside. The flavonol composition varied with cultivar and tissue part. The major flavonol in the bottom segments of the inner perianth was rutin. The iron content in the upper part was less than that in the bottom segments of the inner perianth. The iron content in the yellow and white petals was higher in the bottom segment of the inner perianth than in the upper tissues. TgVit1 mRNA expression was apparent in all of the bottom tissues of the inner perianth. The result of a reproduction experiment by mixing the constituents suggests that the blue coloration in tulip petals is generally caused by iron complexation to delphinidin 3-rutinoside and that the iron complex is solubilized and stabilized by flavonol glycosides. TgVit1-dependent iron accumulation in the bottom segments of the inner perianth might be controlled by an unknown system that differentiated the upper parts and bottom segments of the inner perianth.

  9. Photoperiodic regulation of the sucrose transporter StSUT4 affects the expression of circadian-regulated genes and ethylene production

    Directory of Open Access Journals (Sweden)

    Izabela eChincinska

    2013-02-01

    Full Text Available Several recent publications report different subcellular localisation of members of the SUT4 subfamily of sucrose transporters. The physiological function of SUT4 sucrose transporters is still not entirely clarified as down-regulation of members of the SUT4 clade had very different effects in rice, poplar and potato. Here, we provide new data on the localization and function of the Solanaceous StSUT4 protein, further elucidating involvement in the onset of flowering, tuberization and in the shade avoidance syndrome of potato plants.Induction of early flowering and tuberization in SUT4-inhibited potato plants correlates with increased sucrose export from leaves and increased sucrose and starch accumulation in terminal sink organs such as developing tubers. SUT4 does not only affect the expression of gibberellin and ethylene biosynthetic enzymes, but also the rate of ethylene synthesis in potato. In SUT4-inhibited plants, the ethylene production no longer follows a diurnal rhythm, leading to the assumption that StSUT4 controls circadian gene expression, potentially by regulating sucrose export from leaves. Furthermore, SUT4 expression affects clock-regulated genes such as StFT, StSOC1 and StCO, which might also be involved in a photoperiod-dependently controlled tuberization. A model is proposed in which StSUT4 controls a phloem-mobile signalling molecule generated in leaves which together with enhanced sucrose export affects developmental switches in apical meristems. SUT4 seems to link photoreceptor-perceived information about the light quality and day length, with phytohormone biosynthesis and the expression of circadian genes.

  10. Vacuolar respiration of nitrate coupled to energy conservation in filamentous Beggiatoaceae.

    Science.gov (United States)

    Beutler, Martin; Milucka, Jana; Hinck, Susanne; Schreiber, Frank; Brock, Jörg; Mussmann, Marc; Schulz-Vogt, Heide N; de Beer, Dirk

    2012-11-01

    We show that the nitrate storing vacuole of the sulfide-oxidizing bacterium Candidatus Allobeggiatoa halophila has an electron transport chain (ETC), which generates a proton motive force (PMF) used for cellular energy conservation. Immunostaining by antibodies showed that cytochrome c oxidase, an ETC protein and a vacuolar ATPase are present in the vacuolar membrane and cytochrome c in the vacuolar lumen. The effect of different inhibitors on the vacuolar pH was studied by pH imaging. Inhibition of vacuolar ATPases and pyrophosphatases resulted in a pH decrease in the vacuole, showing that the proton gradient over the vacuolar membrane is used for ATP and pyrophosphate generation. Blockage of the ETC decreased the vacuolar PMF, indicating that the proton gradient is build up by an ETC. Furthermore, addition of nitrate resulted in an increase of the vacuolar PMF. Inhibition of nitrate reduction, led to a decreased PMF. Nitric oxide was detected in vacuoles of cells exposed to nitrate showing that nitrite, the product of nitrate reduction, is reduced inside the vacuole. These findings show consistently that nitrate respiration contributes to the high proton concentration within the vacuole and the PMF over the vacuolar membrane is actively used for energy conservation. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  11. Impaired pH homeostasis in Arabidopsis lacking the vacuolar dicarboxylate transporter and analysis of carboxylic acid transport across the tonoplast.

    Science.gov (United States)

    Hurth, Marco Alois; Suh, Su Jeoung; Kretzschmar, Tobias; Geis, Tina; Bregante, Monica; Gambale, Franco; Martinoia, Enrico; Neuhaus, H Ekkehard

    2005-03-01

    Arabidopsis (Arabidopsis thaliana) mutants lacking the tonoplastic malate transporter AttDT (A. thaliana tonoplast dicarboxylate transporter) and wild-type plants showed no phenotypic differences when grown under standard conditions. To identify putative metabolic changes in AttDT knock-out plants, we provoked a metabolic scenario connected to an increased consumption of dicarboxylates. Acidification of leaf discs stimulated dicarboxylate consumption and led to extremely low levels of dicarboxylates in mutants. To investigate whether reduced dicarboxylate concentrations in mutant leaf cells and, hence, reduced capacity to produce OH(-) to overcome acidification might affect metabolism, we measured photosynthetic oxygen evolution under conditions where the cytosol is acidified. AttDT::tDNA protoplasts showed a much stronger inhibition of oxygen evolution at low pH values when compared to wild-type protoplasts. Apparently citrate, which is present in higher amounts in knock-out plants, is not able to replace dicarboxylates to overcome acidification. To raise more information on the cellular level, we performed localization studies of carboxylates. Although the total pool of carboxylates in mutant vacuoles was nearly unaltered, these organelles contained a lower proportion of malate and fumarate and a higher proportion of citrate when compared to wild-type vacuoles. These alterations concur with the observation that radioactively labeled malate and citrate are transported into Arabidopsis vacuoles by different carriers. In addition, wild-type vacuoles and corresponding organelles from AttDT::tDNA mutants exhibited similar malate channel activities. In conclusion, these results show that Arabidopsis vacuoles contain at least two transporters and a channel for dicarboxylates and citrate and that the activity of AttDT is critical for regulation of pH homeostasis.

  12. Impaired pH Homeostasis in Arabidopsis Lacking the Vacuolar Dicarboxylate Transporter and Analysis of Carboxylic Acid Transport across the Tonoplast1

    Science.gov (United States)

    Hurth, Marco Alois; Suh, Su Jeoung; Kretzschmar, Tobias; Geis, Tina; Bregante, Monica; Gambale, Franco; Martinoia, Enrico; Neuhaus, H. Ekkehard

    2005-01-01

    Arabidopsis (Arabidopsis thaliana) mutants lacking the tonoplastic malate transporter AttDT (A. thaliana tonoplast dicarboxylate transporter) and wild-type plants showed no phenotypic differences when grown under standard conditions. To identify putative metabolic changes in AttDT knock-out plants, we provoked a metabolic scenario connected to an increased consumption of dicarboxylates. Acidification of leaf discs stimulated dicarboxylate consumption and led to extremely low levels of dicarboxylates in mutants. To investigate whether reduced dicarboxylate concentrations in mutant leaf cells and, hence, reduced capacity to produce OH− to overcome acidification might affect metabolism, we measured photosynthetic oxygen evolution under conditions where the cytosol is acidified. AttDT::tDNA protoplasts showed a much stronger inhibition of oxygen evolution at low pH values when compared to wild-type protoplasts. Apparently citrate, which is present in higher amounts in knock-out plants, is not able to replace dicarboxylates to overcome acidification. To raise more information on the cellular level, we performed localization studies of carboxylates. Although the total pool of carboxylates in mutant vacuoles was nearly unaltered, these organelles contained a lower proportion of malate and fumarate and a higher proportion of citrate when compared to wild-type vacuoles. These alterations concur with the observation that radioactively labeled malate and citrate are transported into Arabidopsis vacuoles by different carriers. In addition, wild-type vacuoles and corresponding organelles from AttDT::tDNA mutants exhibited similar malate channel activities. In conclusion, these results show that Arabidopsis vacuoles contain at least two transporters and a channel for dicarboxylates and citrate and that the activity of AttDT is critical for regulation of pH homeostasis. PMID:15728336

  13. AmSUT1, a Sucrose Transporter in Collection and Transport Phloem of the Putative Symplastic Phloem Loader Alonsoa meridionalis1

    Science.gov (United States)

    Knop, Christian; Stadler, Ruth; Sauer, Norbert; Lohaus, Gertrud

    2004-01-01

    A sucrose (Suc) transporter cDNA has been cloned from Alonsoa meridionalis, a member of the Scrophulariaceae. This plant species has an open minor vein configuration and translocates mainly raffinose and stachyose in addition to Suc in the phloem (C. Knop, O. Voitsekhovskaja, G. Lohaus [2001] Planta 213: 80–91). These are typical properties of symplastic phloem loaders. For functional characterization, AmSUT1 cDNA was expressed in bakers' yeast (Saccharomyces cerevisiae). Substrate and inhibitor specificities, energy dependence, and Km value of the protein agree well with the properties measured for other Suc transporters of apoplastic phloem loaders. A polyclonal antiserum against the 17 N-terminal amino acids of the A. meridionalis Suc transporter AmSUT1 was used to determine the cellular localization of the AmSUT1 protein. Using fluorescence labeling on sections from A. meridionalis leaves and stems, AmSUT1 was localized exclusively in phloem cells. Further histological characterization identified these cells as companion cells and sieve elements. p-Chloromercuribenzenesulfonic acid affected the sugar exudation of cut leaves in such a way that the exudation rates of Suc and hexoses decreased, whereas those of raffinose and stachyose increased. The data presented indicate that phloem loading of Suc and retrieval of Suc in A. meridionalis are at least partly mediated by the activity of AmSUT1 in addition to symplastic phloem loading. PMID:14730068

  14. In silico analysis of cis-acting regulatory elements in 5' regulatory regions of sucrose transporter gene families in rice (Oryza sativa Japonica) and Arabidopsis thaliana.

    Science.gov (United States)

    Ibraheem, Omodele; Botha, Christiaan E J; Bradley, Graeme

    2010-12-01

    The regulation of gene expression involves a multifarious regulatory system. Each gene contains a unique combination of cis-acting regulatory sequence elements in the 5' regulatory region that determines its temporal and spatial expression. Cis-acting regulatory elements are essential transcriptional gene regulatory units; they control many biological processes and stress responses. Thus a full understanding of the transcriptional gene regulation system will depend on successful functional analyses of cis-acting elements. Cis-acting regulatory elements present within the 5' regulatory region of the sucrose transporter gene families in rice (Oryza sativa Japonica cultivar-group) and Arabidopsis thaliana, were identified using a bioinformatics approach. The possible cis-acting regulatory elements were predicted by scanning 1.5kbp of 5' regulatory regions of the sucrose transporter genes translational start sites, using Plant CARE, PLACE and Genomatix Matinspector professional databases. Several cis-acting regulatory elements that are associated with plant development, plant hormonal regulation and stress response were identified, and were present in varying frequencies within the 1.5kbp of 5' regulatory region, among which are; A-box, RY, CAT, Pyrimidine-box, Sucrose-box, ABRE, ARF, ERE, GARE, Me-JA, ARE, DRE, GA-motif, GATA, GT-1, MYC, MYB, W-box, and I-box. This result reveals the probable cis-acting regulatory elements that possibly are involved in the expression and regulation of sucrose transporter gene families in rice and Arabidopsis thaliana during cellular development or environmental stress conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. A Medicago truncatula H+-pyrophosphatase gene, MtVP1, improves sucrose accumulation and anthocyanin biosynthesis in potato (Solanum tuberosum L.).

    Science.gov (United States)

    Wang, J W; Wang, H Q; Xiang, W W; Chai, T Y

    2014-05-09

    We recently cloned MtVP1, a type I vacuolar-type H(+)-translocating inorganic pyrophosphatase from Medicago truncatula. In the present study, we investigated the cellular location and the function of this H(+)-PPase in Arabidopsis and potato (Solanum tuberosum L.). An MtVP1::enhanced green fluorescent protein fusion was constructed, which localized to the plasma membrane of onion epidermal cells. Transgenic Arabidopsis thaliana overexpressing MtVP1 had more robust root systems and redder shoots than wild-type (WT) plants under conditions of cold stress. Furthermore, overexpression of MtVP1 in potato accelerated the formation and growth of vegetative organs. The tuber buds and stem base of transgenic potatoes became redder than those of WT plants, but flowering was delayed by approximately half a month. Interestingly, anthocyanin biosynthesis was promoted in transgenic Arabidopsis seedlings and potato tuber buds. The sucrose concentration of transgenic potato tubers and tuber buds was enhanced compared with that of WT plants. Furthermore, sucrose concentration in tubers was higher than that in tuber buds. Although there was no direct evidence to support Fuglsang's hypothetical model regarding the effects of H(+)-PPase on sucrose phloem loading, we speculated that sucrose concentration was increased in tuber buds owing to the increased concentration in tubers. Therefore, overexpressed MtVP1 enhanced sucrose accumulation of source organs, which might enhance sucrose transport to sink organs, thus affecting anthocyanin biosynthesis.

  16. Radiosynthesis of 6’-Deoxy-6’[18F]Fluorosucrose via Automated Synthesis and Its Utility to Study In Vivo Sucrose Transport in Maize (Zea mays) Leaves

    Science.gov (United States)

    Ying, Weijiang; Gaddam, Vikram; Harmata, Michael; Robertson, J. David; Swyers, Michael; Jurisson, Silvia S.

    2015-01-01

    Sugars produced from photosynthesis in leaves are transported through the phloem tissues within veins and delivered to non-photosynthetic organs, such as roots, stems, flowers, and seeds, to support their growth and/or storage of carbohydrates. However, because the phloem is located internally within the veins, it is difficult to access and to study the dynamics of sugar transport. Radioactive tracers have been extensively used to study vascular transport in plants and have provided great insights into transport dynamics. To better study sucrose partitioning in vivo, a novel radioactive analog of sucrose was synthesized through a completely chemical synthesis route by substituting fluorine-18 (half-life 110 min) at the 6’ position to generate 6’-deoxy-6’[18F]fluorosucrose (18FS). This radiotracer was then used to compare sucrose transport between wild-type maize plants and mutant plants lacking the Sucrose transporter1 (Sut1) gene, which has been shown to function in sucrose phloem loading. Our results demonstrate that 18FS is transported in vivo, with the wild-type plants showing a greater rate of transport down the leaf blade than the sut1 mutant plants. A similar transport pattern was also observed for universally labeled [U-14C]sucrose ([U-14C]suc). Our findings support the proposed sucrose phloem loading function of the Sut1 gene in maize, and additionally demonstrate that the 18FS analog is a valuable, new tool that offers imaging advantages over [U-14C]suc for studying phloem transport in plants. PMID:26024520

  17. Miopatia vacuolar do lupus eritematoso

    Directory of Open Access Journals (Sweden)

    José Antonio Levy

    1962-06-01

    Full Text Available Após considerações rápidas sôbre as miosites, particularmente sôbre a miopatia vacuolar do lúpus eritematoso, é relatado o caso de uma paciente no qual êsse diagnóstico pôde ser confirmado pelo exame histopatológico.

  18. The Amborella vacuolar processing enzyme family

    Directory of Open Access Journals (Sweden)

    Valérie ePoncet

    2015-08-01

    Full Text Available Most vacuolar proteins are synthesized on rough endoplasmic reticulum as proprotein precursors and then transported to the vacuoles, where they are converted into their respective mature forms by vacuolar processing enzymes (VPEs. In the case of the seed storage proteins, this process is of major importance, as it conditions the establishment of vigorous seedlings. Toward the goal of identifying proteome signatures that could be associated with the origin and early diversification of angiosperms, we previously characterized the 11S-legumin-type of seed storage proteins from Amborella trichopoda, a rainforest shrub endemic to New Caledonia that is also the probable sister to all other angiosperms (Amborella Genome Project, 2013. In the present study, proteomic and genomic approaches were used to characterize the VPE family in this species. Three genes were found to encode VPEs in the Amborella’s genome. Phylogenetic analyses showed that the Amborella sequences grouped within two major clades of angiosperm VPEs, indicating that the duplication that generated the ancestors of these clades occurred before the most recent common ancestor of living angiosperms. A further important duplication within the VPE family appears to have occurred in common ancestor of the core eudicots, while many more recent duplications have also occurred in specific taxa, including both Arabidopsis thaliana and Amborella. An analysis of natural genetic variation for each of the three Amborella VPE genes revealed the absence of selective forces acting on intronic and exonic single-nucleotide polymorphisms among several natural Amborella populations of in New Caledonia.

  19. Vacuolar structures can be identified by AFM elasticity mapping

    International Nuclear Information System (INIS)

    Riethmueller, Christoph; Schaeffer, Tilman E.; Kienberger, Ferry; Stracke, Werner; Oberleithner, Hans

    2007-01-01

    Fluid-filled organelles like vesicles, endosomes and pinosomes are inevitable parts of cellular signalling and transport. Endothelial cells, building a barrier between blood and tissue, can form vacuolar organelles. These structures are implicated in upregulated fluid transport across the endothelium under inflammatory conditions. Vacuolar organelles have been described by transmission electron microscopy so far. Here, we present a method that images and mechanically characterizes intracellular structures in whole cells by atomic force microscopy (AFM). After crosslinking the cellular proteins with the fixative glutaraldehyde, plasma membrane depressions become observable, which are scattered around the cell nucleus. Nanomechanical analysis identifies them as spots of reduced stiffness. Scanning electron microscopy confirms their pit-like appearance. In addition, fluorescence microscopy detects an analogous pattern of protein-poor spots, thereby confirming mechanical rigidity to arise from crosslinked proteins. This AFM application opens up a mechanical dimension for the investigation of intracellular organelles

  20. Sucrose preload reduces snacking after mild mental stress in healthy participants as a function of 5-hydroxytryptamine transporter gene promoter polymorphism.

    Science.gov (United States)

    Markus, C Rob; Jonkman, Lisa M; Capello, Aimee; Leinders, Sacha; Hüsch, Fabian

    2015-01-01

    Brain serotonin (5-hydroxytryptamine, 5-HT) dysfunction is considered to promote food intake and eating-related disturbances, especially under stress or negative mood. Vulnerability for 5-HT disturbances is considered to be genetically determined, including a short (S) allele polymorphism in the serotonin transporter gene (5-HTTLPR) that is associated with lower serotonin function. Since 5-HT function may be slightly increased by carbohydrate consumption, S-allele 5-HTTLPR carriers in particular may benefit from a sugar-preload due to their enhanced 5-HT vulnerability. The aim of the current study was to investigate whether a sugar-containing preload may reduce appetite and energy intake after exposure to stress to induce negative mood, depending on genetic 5-HT vulnerability. From a population of 771 healthy young male and female genotyped college students 31 S/S carriers (8 males, 23 females) and 26 long allele (L/L) carriers (9 males, 17 females) (mean ± S.D. 22 ± 1.6 years; body mass index, BMI, 18-33 kg/m(2)) were monitored for changes in appetite and snacking behavior after stress exposure. Results revealed an increased energy intake after mild mental stress (negative mood) mainly for high-fat sweet foods, which was significantly greater in S/S carriers, and only in these genotypes this intake was significantly reduced by a sucrose-containing preload. Although alternative explanations are possible, it is suggested that S/S participants may have enhanced brain (hypothalamic) 5-HT responsiveness to food that makes them more susceptible to the beneficial satiation effects of a sucrose-preload as well as to the negative effects of mild mental stress on weight gain.

  1. Sucrose nonfermenting AMPK-related kinase (SNARK) mediates contraction-stimulated glucose transport in mouse skeletal muscle

    OpenAIRE

    Koh, Ho-Jin; Toyoda, Taro; Fujii, Nobuharu; Jung, Michelle M.; Rathod, Amee; Middelbeek, R. Jan-Willem; Lessard, Sarah J.; Treebak, Jonas T.; Tsuchihara, Katsuya; Esumi, Hiroyasu; Richter, Erik A.; Wojtaszewski, Jørgen F. P.; Hirshman, Michael F.; Goodyear, Laurie J.

    2010-01-01

    The signaling mechanisms that mediate the important effects of contraction to increase glucose transport in skeletal muscle are not well understood, but are known to occur through an insulin-independent mechanism. Muscle-specific knockout of LKB1, an upstream kinase for AMPK and AMPK-related protein kinases, significantly inhibited contraction-stimulated glucose transport. This finding, in conjunction with previous studies of ablated AMPKα2 activity showing no effect on contraction-stimulated...

  2. Sucrose nonfermenting AMPK-related kinase (SNARK) mediates contraction-stimulated glucose transport in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Koh, Ho-Jin; Toyoda, Taro; Fujii, Nobuharu

    2010-01-01

    The signaling mechanisms that mediate the important effects of contraction to increase glucose transport in skeletal muscle are not well understood, but are known to occur through an insulin-independent mechanism. Muscle-specific knockout of LKB1, an upstream kinase for AMPK and AMPK-related prot...

  3. Vacuolar Chloride Fluxes Impact Ion Content and Distribution during Early Salinity Stress1

    Science.gov (United States)

    Baetz, Ulrike; Tohge, Takayuki; Martinoia, Enrico; De Angeli, Alexis

    2016-01-01

    The ability to control the cytoplasmic environment is a prerequisite for plants to cope with changing environmental conditions. During salt stress, for instance, Na+ and Cl− are sequestered into the vacuole to help maintain cytosolic ion homeostasis and avoid cellular damage. It has been observed that vacuolar ion uptake is tied to fluxes across the plasma membrane. The coordination of both transport processes and relative contribution to plant adaptation, however, is still poorly understood. To investigate the link between vacuolar anion uptake and whole-plant ion distribution during salinity, we used mutants of the only vacuolar Cl− channel described to date: the Arabidopsis (Arabidopsis thaliana) ALMT9. After 24-h NaCl treatment, almt9 knock-out mutants had reduced shoot accumulation of both Cl− and Na+. In contrast, almt9 plants complemented with a mutant variant of ALMT9 that exhibits enhanced channel activity showed higher Cl− and Na+ accumulation. The altered shoot ion contents were not based on differences in transpiration, pointing to a vacuolar function in regulating xylem loading during salinity. In line with this finding, GUS staining demonstrated that ALMT9 is highly expressed in the vasculature of shoots and roots. RNA-seq analysis of almt9 mutants under salinity revealed specific expression profiles of transporters involved in long-distance ion translocation. Taken together, our study uncovers that the capacity of vacuolar Cl− loading in vascular cells plays a crucial role in controlling whole-plant ion movement rapidly after onset of salinity. PMID:27503602

  4. The Arabidopsis vacuolar malate channel is a member of the ALMT family.

    Science.gov (United States)

    Kovermann, Peter; Meyer, Stefan; Hörtensteiner, Stefan; Picco, Cristiana; Scholz-Starke, Joachim; Ravera, Silvia; Lee, Youngsook; Martinoia, Enrico

    2007-12-01

    In plants, malate is a central metabolite and fulfills a large number of functions. Vacuolar malate may reach very high concentrations and fluctuate rapidly, whereas cytosolic malate is kept at a constant level allowing optimal metabolism. Recently, a vacuolar malate transporter (Arabidopsis thaliana tonoplast dicarboxylate transporter, AttDT) was identified that did not correspond to the well-characterized vacuolar malate channel. We therefore hypothesized that a member of the aluminum-activated malate transporter (ALMT) gene family could code for a vacuolar malate channel. Using GFP fusion constructs, we could show that AtALMT9 (A. thaliana ALMT9) is targeted to the vacuole. Promoter-GUS fusion constructs demonstrated that this gene is expressed in all organs, but is cell-type specific as GUS activity in leaves was detected nearly exclusively in mesophyll cells. Patch-clamp analysis of an Atalmt9 T-DNA insertion mutant exhibited strongly reduced vacuolar malate channel activity. In order to functionally characterize AtALMT9 as a malate channel, we heterologously expressed this gene in tobacco and in oocytes. Overexpression of AtALMT9-GFP in Nicotiana benthamiana leaves strongly enhanced the malate current densities across the mesophyll tonoplasts. Functional expression of AtALMT9 in Xenopus oocytes induced anion currents, which were clearly distinguishable from endogenous oocyte currents. Our results demonstrate that AtALMT9 is a vacuolar malate channel. Deletion mutants for AtALMT9 exhibit only slightly reduced malate content in mesophyll protoplasts and no visible phenotype, indicating that AttDT and the residual malate channel activity are sufficient to sustain the transport activity necessary to regulate the cytosolic malate homeostasis.

  5. Characterization of Sugar Contents and Sucrose Metabolizing Enzymes in Developing Leaves of Hevea brasiliensis

    Directory of Open Access Journals (Sweden)

    Jinheng Zhu

    2018-02-01

    Full Text Available Sucrose-metabolizing enzymes in plant leaves have hitherto been investigated mainly in temperate plants, and rarely conducted in tandem with gene expression and sugar analysis. Here, we investigated the sugar content, gene expression, and the activity of sucrose-metabolizing enzymes in the leaves of Hevea brasiliensis, a tropical tree widely cultivated for natural rubber. Sucrose, fructose and glucose were the major sugars detected in Hevea leaves at four developmental stages (I to IV, with starch and quebrachitol as minor saccharides. Fructose and glucose contents increased until stage III, but decreased strongly at stage IV (mature leaves. On the other hand, sucrose increased continuously throughout leaf development. Activities of all sucrose-cleaving enzymes decreased markedly at maturation, consistent with transcript decline for most of their encoding genes. Activity of sucrose phosphate synthase (SPS was low in spite of its high transcript levels at maturation. Hence, the high sucrose content in mature leaves was not due to increased sucrose-synthesizing activity, but more to the decline in sucrose cleavage. Gene expression and activities of sucrose-metabolizing enzymes in Hevea leaves showed striking differences compared with other plants. Unlike in most other species where vacuolar invertase predominates in sucrose cleavage in developing leaves, cytoplasmic invertase and sucrose synthase (cleavage direction also featured prominently in Hevea. Whereas SPS is normally responsible for sucrose synthesis in plant leaves, sucrose synthase (synthesis direction was comparable or higher than that of SPS in Hevea leaves. Mature Hevea leaves had an unusually high sucrose:starch ratio of about 11, the highest reported to date in plants.

  6. Regulation of Vacuolar pH in Citrus limon

    Energy Technology Data Exchange (ETDEWEB)

    Lincoln Taiz

    2005-06-22

    The primary objective of this grant was to characterize the vacuolar V-ATPase of lemon fruits. Lemon fruit vacuoles have an internal pH of about 2.5. Since a typical plant vacuole has a luminal pH of around 5.5, the lemon fruit V-APTase must have special properties which allow it to acidify the lumen to such a low pH: (1) it might have a different structure; (2) it might have a different H{sup +}/ATP stoichiometry; and (3) it might be regulated differently. During the course of the investigations (which began in 1996) they characterized these aspects of the V-ATPases of both lemon fruits and lime fruits. They examined lime fruits because of the availability of both acidic limes with a low vacuolar pH and sweet limes, which have a much higher vacuolar pH. The existence of two types of lime fruits allowed a comparison of the V-ATPases of the two varieties. In this report they are including two publications from 1996 and 1997 as background for the later publications. A review article with Heven Sze on V-ATPase nomenclature was also generated during the funding period. In addition to the studies on citrus fruit vacuoles, they also initiated studies in two new areas: polar auxin transport and the regulation of stomatal opening by UV-B irradiation. These studies were intended to serve as a basis of future separate grants, but the proposals they submitted on these topics were not funded.

  7. TAI vacuolar invertase orthologs: the interspecific variability in tomato plants (Solanum section Lycopersicon).

    Science.gov (United States)

    Slugina, M A; Shchennikova, A V; Kochieva, E Z

    2017-10-01

    Understanding the genetic mechanisms underlying carbohydrate metabolism can promote the development of biotechnological advances in fruit plants. The flesh tomato fruit represents an ideal system for examining the role of sucrose cleavage enzymes in fruit development, and wild tomato species differing in storage sugars serve as an excellent research material for this purpose. Plant vacuolar invertase is a key enzyme of sucrose metabolism in the sink organs. In the present study, we identified complete gene sequences encoding the TAI vacuolar invertase in 11 wild and one cultivated tomato accessions of the Solanum section Lycopersicon. The average level of interspecific polymorphism in TAI genes was 8.58%; however, in the green-fruited tomatoes, the TAI genes contained 100 times more SNPs than those in the red-fruited accessions. The TAI proteins demonstrated 8% variability, whereas the red-fruited species had none. A TAI-based phylogenetic tree revealed two main clusters containing self-compatible and self-incompatible species, which concurs with the previous crossability-based division and demonstrates that the TAI genes reflect the evolutionary relationships between the red- and green-fruited tomatoes. Furthermore, we detected differential expression patterns of the TAI genes in the fruits of wild and cultivated tomatoes, which corresponded to sugar composition. The polymorphism analysis of the TAI acid invertases of Solanum section Lycopersicon species will contribute to the understanding of the genetic potential of TAI genes to impact tomato breeding through genetic engineering of the carbohydrate composition in the fruit.

  8. Structural studies of the vacuolar membrane ATPase from Neurospora crassa and comparison with the tonoplast membrane ATPase and Zea mays

    International Nuclear Information System (INIS)

    Bowman, E.J.; Mandala, S.; Taiz, L.; Bowman, B.J.

    1986-01-01

    The H + translocating ATPase located on vacuolar membranes of Neurospora crassa was partially purified by solubilization in two detergents, Triton X-100 and N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, followed by centrifugation on sucrose density gradients. Two polypeptides of M/sub r/ ≅ 70,000 and ≅ 62,000 consistently migrated with activity, along with several minor bands of lower molecular weight. Radioactively labeled inhibitors of ATPase activity, N-[ 14 C]ethylmaleimide and 7-chloro-4-nitro[ 14 C]benzo-2-oxa-1,3-diazole, labeled the M/sub r/ ≅ 70,000 polypeptide; this labeling was reduced in the presence of ATP. N,N'-[ 14 C]dicyclohexylcarbodiimide labeled a polypeptide of M/sub r/ ≅ 15,000. Estimation of the functional size of the vacuolar membrane ATPase by radiation inactivation gave a value of M/sub r/ 5.2 x 10 5 , 10-15% larger than the mitochondrial ATPase. The Neurospora vacuolar ATPase showed no crossreactivity with antiserum to plasma membrane or mitochrondrial ATPase but stongly crossreacted with antiserum against a polypeptide of M/sub r/ ≅ 70,000 associated with the tonoplast ATPase of corn coleoptiles. These results suggest that fungal and plant vacuolar ATPases may be large multisubunit complexes, somewhat similar to, but immunologically distinct from, known F 0 F 1 ATPases

  9. The plant vacuolar Na+/H+ antiport.

    Science.gov (United States)

    Barkla, B J; Apse, M P; Manolson, M F; Blumwald, E

    1994-01-01

    Salt stress imposes severe limitations on plant growth, however, the extent of growth reduction depends upon the soil salinity level and the plant species. One of the mechanisms employed by salt tolerant plants is the effective vacuolar compartmentalization of sodium. The sequestration of sodium into the vacuole occurs by the operation of a Na+/H+ antiport located at the tonoplast. Evidence for a plant vacuolar Na+/H+ antiport has been demonstrated in tissues, intact vacuoles and isolated tonoplast vesicles. In sugar beet cell suspensions, the activity of the vacuolar Na+/H+ antiport increased with increasing NaCl concentrations in the growth medium. This increased activity was correlated with the increased synthesis of a 170 kDa tonoplast polypeptide. In vivo labelling of tonoplast proteins showed the enhanced synthesis of the 170 kDa polypeptide not only upon exposure of the cells to salt, but also when the cells were grown in the presence of amiloride. Exposure of the cells to amiloride also resulted in increased vacuolar Na+/H+ antiport activity. Polyclonal antibodies raised against the 170 kDa polypeptide almost completely inhibited the antiport activity, suggesting the association of this protein with the plant vacuolar Na+/H+ antiport. Antibodies against the Na+/H+ antiport-associated polypeptide were used to screen a Beta lambda ZAP expression library. A partial clone of 1.65 kb was sequenced and found to encode a polypeptide with a putative transmembrane domain and a large hydrophilic C terminus. This clone showed no homology to any previously cloned gene at either the nucleic acid or the amino acid level.

  10. The plant homolog to the human sodium/dicarboxylic cotransporter is the vacuolar malate carrier.

    Science.gov (United States)

    Emmerlich, Vera; Linka, Nicole; Reinhold, Thomas; Hurth, Marco A; Traub, Michaela; Martinoia, Enrico; Neuhaus, H Ekkehard

    2003-09-16

    Malate plays a central role in plant metabolism. It is an intermediate in the Krebs and glyoxylate cycles, it is the store for CO2 in C4 and crassulacean acid metabolism plants, it protects plants from aluminum toxicity, it is essential for maintaining the osmotic pressure and charge balance, and it is therefore involved in regulation of stomatal aperture. To fulfil many of these roles, malate has to be accumulated within the large central vacuole. Many unsuccessful efforts have been made in the past to identify the vacuolar malate transporter; here, we describe the identification of the vacuolar malate transporter [A. thaliana tonoplast dicarboxylate transporter (AttDT)]. This transporter exhibits highest sequence similarity to the human sodium/dicarboxylate cotransporter. Independent T-DNA [portion of the Ti (tumor-inducing) plasmid that is transferred to plant cells] Arabidopsis mutants exhibit substantially reduced levels of leaf malate, but respire exogenously applied [14C]malate faster than the WT. An AttDT-GFP fusion protein was localized to vacuole. Vacuoles isolated from Arabidopsis WT leaves exhibited carbonylcyanide m-chlorophenylhydrazone and citrate inhibitable malate transport, which was not stimulated by sodium. Vacuoles isolated from mutant plants import [14C]-malate at strongly reduced rates, confirming that this protein is the vacuolar malate transporter.

  11. Complete Sucrose Metabolism Requires Fructose Phosphotransferase Activity in Corynebacterium glutamicum To Ensure Phosphorylation of Liberated Fructose

    OpenAIRE

    Dominguez, H.; Lindley, N. D.

    1996-01-01

    Sucrose uptake by Corynebacterium glutamicum involves a phosphoenolpyruvate-dependent sucrose phosphotransferase (PTS), but in the absence of fructokinase, further metabolism of the liberated fructose requires efflux of the fructose and reassimilation via the fructose PTS. Mutant strains lacking detectable fructose-transporting PTS activity accumulated fructose extracellularly but consumed sucrose at rates comparable to those of the wild-type strain.

  12. Cytosolic nucleotides block and regulate the Arabidopsis vacuolar anion channel AtALMT9.

    Science.gov (United States)

    Zhang, Jingbo; Martinoia, Enrico; De Angeli, Alexis

    2014-09-12

    The aluminum-activated malate transporters (ALMTs) form a membrane protein family exhibiting different physiological roles in plants, varying from conferring tolerance to environmental Al(3+) to the regulation of stomatal movement. The regulation of the anion channels of the ALMT family is largely unknown. Identifying intracellular modulators of the activity of anion channels is fundamental to understanding their physiological functions. In this study we investigated the role of cytosolic nucleotides in regulating the activity of the vacuolar anion channel AtALMT9. We found that cytosolic nucleotides modulate the transport activity of AtALMT9. This modulation was based on a direct block of the pore of the channel at negative membrane potentials (open channel block) by the nucleotide and not by a phosphorylation mechanism. The block by nucleotides of AtALMT9-mediated currents was voltage dependent. The blocking efficiency of intracellular nucleotides increased with the number of phosphate groups and ATP was the most effective cellular blocker. Interestingly, the ATP block induced a marked modification of the current-voltage characteristic of AtALMT9. In addition, increased concentrations of vacuolar anions were able to shift the ATP block threshold to a more negative membrane potential. The block of AtALMT9-mediated anion currents by ATP at negative membrane potentials acts as a gate of the channel and vacuolar anion tune this gating mechanism. Our results suggest that anion transport across the vacuolar membrane in plant cells is controlled by cytosolic nucleotides and the energetic status of the cell. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Cytosolic Nucleotides Block and Regulate the Arabidopsis Vacuolar Anion Channel AtALMT9*

    Science.gov (United States)

    Zhang, Jingbo; Martinoia, Enrico; De Angeli, Alexis

    2014-01-01

    The aluminum-activated malate transporters (ALMTs) form a membrane protein family exhibiting different physiological roles in plants, varying from conferring tolerance to environmental Al3+ to the regulation of stomatal movement. The regulation of the anion channels of the ALMT family is largely unknown. Identifying intracellular modulators of the activity of anion channels is fundamental to understanding their physiological functions. In this study we investigated the role of cytosolic nucleotides in regulating the activity of the vacuolar anion channel AtALMT9. We found that cytosolic nucleotides modulate the transport activity of AtALMT9. This modulation was based on a direct block of the pore of the channel at negative membrane potentials (open channel block) by the nucleotide and not by a phosphorylation mechanism. The block by nucleotides of AtALMT9-mediated currents was voltage dependent. The blocking efficiency of intracellular nucleotides increased with the number of phosphate groups and ATP was the most effective cellular blocker. Interestingly, the ATP block induced a marked modification of the current-voltage characteristic of AtALMT9. In addition, increased concentrations of vacuolar anions were able to shift the ATP block threshold to a more negative membrane potential. The block of AtALMT9-mediated anion currents by ATP at negative membrane potentials acts as a gate of the channel and vacuolar anion tune this gating mechanism. Our results suggest that anion transport across the vacuolar membrane in plant cells is controlled by cytosolic nucleotides and the energetic status of the cell. PMID:25028514

  14. Oligosaccharides Derived from Sucrose

    Science.gov (United States)

    Monsan, Pierre F.; Ouarné, Francois

    Sucrose is a non-reducing disaccharide, consisting of an α-D-glucopyranosyl residue and a β-D-fructofuranosyl residue linked covalently by their respective anomeric carbons (α-D-glucopyranosyl-1,2-β-D-fructofuranoside). It is not just a simple disaccharide, among others: in fact, the energy of its glycosidic bond is higher than that of a usual glycosidic bond. It is equal to 27.6 kJ/mol, which is similar to the energy of a nucleotide-sugar bond as in UDP-glucose or ADP-glucose. This means that sucrose is a protected and activated form of D-glucose (as well as of D-fructose), which plays a key role in the metabolism of plants, for a wide variety of synthesis reactions.

  15. Sucrose assimilation and the role of sucrose transporters in plant ...

    African Journals Online (AJOL)

    Plant cells are commonly exposed to a variety of injuries such as mechanical and herbivore ... changes in gene repression that contribute to cell defense and repairs. ... tissues or cells can only be met by an increased utilization of exogenously ...

  16. Glycolytic control of vacuolar-type ATPase activity: A mechanism to regulate influenza viral infection

    Energy Technology Data Exchange (ETDEWEB)

    Kohio, Hinissan P.; Adamson, Amy L., E-mail: aladamso@uncg.edu

    2013-09-15

    As new influenza virus strains emerge, finding new mechanisms to control infection is imperative. In this study, we found that we could control influenza infection of mammalian cells by altering the level of glucose given to cells. Higher glucose concentrations induced a dose-specific increase in influenza infection. Linking influenza virus infection with glycolysis, we found that viral replication was significantly reduced after cells were treated with glycolytic inhibitors. Addition of extracellular ATP after glycolytic inhibition restored influenza infection. We also determined that higher levels of glucose promoted the assembly of the vacuolar-type ATPase within cells, and increased vacuolar-type ATPase proton-transport activity. The increase of viral infection via high glucose levels could be reversed by inhibition of the proton pump, linking glucose metabolism, vacuolar-type ATPase activity, and influenza viral infection. Taken together, we propose that altering glucose metabolism may be a potential new approach to inhibit influenza viral infection. - Highlights: • Increased glucose levels increase Influenza A viral infection of MDCK cells. • Inhibition of the glycolytic enzyme hexokinase inhibited Influenza A viral infection. • Inhibition of hexokinase induced disassembly the V-ATPase. • Disassembly of the V-ATPase and Influenza A infection was bypassed with ATP. • The state of V-ATPase assembly correlated with Influenza A infection of cells.

  17. Glycolytic control of vacuolar-type ATPase activity: A mechanism to regulate influenza viral infection

    International Nuclear Information System (INIS)

    Kohio, Hinissan P.; Adamson, Amy L.

    2013-01-01

    As new influenza virus strains emerge, finding new mechanisms to control infection is imperative. In this study, we found that we could control influenza infection of mammalian cells by altering the level of glucose given to cells. Higher glucose concentrations induced a dose-specific increase in influenza infection. Linking influenza virus infection with glycolysis, we found that viral replication was significantly reduced after cells were treated with glycolytic inhibitors. Addition of extracellular ATP after glycolytic inhibition restored influenza infection. We also determined that higher levels of glucose promoted the assembly of the vacuolar-type ATPase within cells, and increased vacuolar-type ATPase proton-transport activity. The increase of viral infection via high glucose levels could be reversed by inhibition of the proton pump, linking glucose metabolism, vacuolar-type ATPase activity, and influenza viral infection. Taken together, we propose that altering glucose metabolism may be a potential new approach to inhibit influenza viral infection. - Highlights: • Increased glucose levels increase Influenza A viral infection of MDCK cells. • Inhibition of the glycolytic enzyme hexokinase inhibited Influenza A viral infection. • Inhibition of hexokinase induced disassembly the V-ATPase. • Disassembly of the V-ATPase and Influenza A infection was bypassed with ATP. • The state of V-ATPase assembly correlated with Influenza A infection of cells

  18. Intense pseudotransport of a cationic drug mediated by vacuolar ATPase: Procainamide-induced autophagic cell vacuolization

    International Nuclear Information System (INIS)

    Morissette, Guillaume; Lodge, Robert; Marceau, Francois

    2008-01-01

    Cationic drugs frequently exhibit large apparent volumes of distribution, consistent with various forms of cellular sequestration. The contributions of organelles and metabolic processes that may mimic drug transport were defined in human vascular smooth muscle cells. We hypothesized that procainamide-induced vacuolar cytopathology is driven by intense pseudotransport mediated by the vacuolar (V)-ATPase and pursued the characterization of vesicular trafficking alterations in this model. Large amounts of procainamide were taken up by intact cells (maximal in 2 h, reversible upon washout, apparent K M 4.69 mM; fluorometric determination of cell-associated drug). Procainamide uptake was extensively prevented or reversed by pharmacological inhibition of the V-ATPase with bafilomycin A1 or FR 167356, decreased at low extracellular pH and preceded vacuolar cell morphology. However, the uptake of procainamide was unaffected by mitochondrial poisons that reduced the uptake of rhodamine 6G. Large vacuoles induced by millimolar procainamide were labeled with the late endosome/lysosome markers Rab7 and CD63 and the autophagy effector LC3; their osmotic formation (but not procainamide uptake) was reduced by extracellular mannitol and parallel to LC3 II formation. Procainamide-induced vacuolization is associated with defective endocytosis of fluorophore-labeled bovine serum albumin, but not with induction of the unfolded protein response. The contents of a vacuole subset slowly (≥ 24 h) become positive for Nile red staining (phospholipidosis-like response). V-ATPase-driven ion trapping is a form of intense cation pseudotransport that concerns the uncharged form of the drugs, and is associated with a vacuolar, autophagic and evolutive cytopathology and profound effects on vesicular trafficking

  19. Sucrose Phosphate Synthase and Sucrose Accumulation at Low Temperature 1

    Science.gov (United States)

    Guy, Charles L.; Huber, Joan L. A.; Huber, Steven C.

    1992-01-01

    The influence of growth temperature on the free sugar and sucrose phosphate synthase content and activity of spinach (Spinacia oleracea) leaf tissue was studied. When plants were grown at 25°C for 3 weeks and then transferred to a constant 5°C, sucrose, glucose, and fructose accumulated to high levels during a 14-d period. Predawn sugar levels increased from 14- to 20-fold over the levels present at the outset of the low-temperature treatment. Sucrose was the most abundant free sugar before, during, and after exposure to 5°C. Leaf sucrose phosphate synthase activity was significantly increased by the low-temperature treatment, whereas sucrose synthase and invertases were not. Synthesis of the sucrose phosphate synthase subunit was increased during and after low-temperature exposure and paralleled an increase in the steady-state level of the subunit. The increases in sucrose and its primary biosynthetic enzyme, sucrose phosphate synthase, are discussed in relation to adjustment of metabolism to low nonfreezing temperature and freezing stress tolerance. Images Figure 1 Figure 2 Figure 3 PMID:16652990

  20. Switching the mode of sucrose utilization by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Miletti Luiz C

    2008-02-01

    Full Text Available Abstract Background Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. Results We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Conclusion Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by

  1. Switching the mode of sucrose utilization by Saccharomyces cerevisiae.

    Science.gov (United States)

    Badotti, Fernanda; Dário, Marcelo G; Alves, Sergio L; Cordioli, Maria Luiza A; Miletti, Luiz C; de Araujo, Pedro S; Stambuk, Boris U

    2008-02-27

    Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L) initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by effectively reducing sucrose uptake by the yeast cells

  2. Job Sharing in the Endomembrane System: Vacuolar Acidification Requires the Combined Activity of V-ATPase and V-PPase.

    Science.gov (United States)

    Kriegel, Anne; Andrés, Zaida; Medzihradszky, Anna; Krüger, Falco; Scholl, Stefan; Delang, Simon; Patir-Nebioglu, M Görkem; Gute, Gezahegn; Yang, Haibing; Murphy, Angus S; Peer, Wendy Ann; Pfeiffer, Anne; Krebs, Melanie; Lohmann, Jan U; Schumacher, Karin

    2015-12-01

    The presence of a large central vacuole is one of the hallmarks of a prototypical plant cell, and the multiple functions of this compartment require massive fluxes of molecules across its limiting membrane, the tonoplast. Transport is assumed to be energized by the membrane potential and the proton gradient established by the combined activity of two proton pumps, the vacuolar H(+)-pyrophosphatase (V-PPase) and the vacuolar H(+)-ATPase (V-ATPase). Exactly how labor is divided between these two enzymes has remained elusive. Here, we provide evidence using gain- and loss-of-function approaches that lack of the V-ATPase cannot be compensated for by increased V-PPase activity. Moreover, we show that increased V-ATPase activity during cold acclimation requires the presence of the V-PPase. Most importantly, we demonstrate that a mutant lacking both of these proton pumps is conditionally viable and retains significant vacuolar acidification, pointing to a so far undetected contribution of the trans-Golgi network/early endosome-localized V-ATPase to vacuolar pH. © 2015 American Society of Plant Biologists. All rights reserved.

  3. Metabolic engineering to expand the substrate spectrum of Pseudomonas putida toward sucrose.

    Science.gov (United States)

    Löwe, Hannes; Schmauder, Lukas; Hobmeier, Karina; Kremling, Andreas; Pflüger-Grau, Katharina

    2017-08-01

    Sucrose is an important disaccharide used as a substrate in many industrial applications. It is a major component of molasses, a cheap by-product of the sugar industry. Unfortunately, not all industrially relevant organisms, among them Pseudomonas putida, are capable of metabolizing sucrose. We chose a metabolic engineering approach to circumvent this blockage and equip P. putida with the activities necessary to consume sucrose. Therefore, we constructed a pair of broad-host range mini-transposons (pSST - sucrose splitting transposon), carrying either cscA, encoding an invertase able to split sucrose into glucose and fructose, or additionally cscB, encoding a sucrose permease. Introduction of cscA was sufficient to convey sucrose consumption and the additional presence of cscB had no further effect, though the sucrose permease was built and localized to the membrane. Sucrose was split extracellularly by the activity of the invertase CscA leaking out of the cell. The transposons were also used to confer sucrose consumption to Cupriavidus necator. Interestingly, in this strain, CscB acted as a glucose transporter, such that C. necator also gained the ability to grow on glucose. Thus, the pSST transposons are functional tools to extend the substrate spectrum of Gram-negative bacterial strains toward sucrose. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  4. Co-overexpressing a plasma membrane and a vacuolar membrane sodium/proton antiporter significantly improves salt tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    The Arabidopsis gene AtNHX1 encodes a vacuolar membrane bound sodium/proton (Sodium/Hydrogen) antiporter that transports sodium into the vacuole and exports hydrogen into the cytoplasm. The Arabidopsis gene SOS1 encodes a plasma membrane bound sodium/hydrogen antiporter that exports sodium to the ex...

  5. Additional synthesis of starch from sucrose in leaves of arabidopsis in the light

    International Nuclear Information System (INIS)

    Keerberg, O.; Ivanova, H.; Keerberg, H.; Paernik, T.

    2005-01-01

    Full text: Accumulating during daytime starch is converted in the night into sucrose and consumed in respiratory, biosynthetic and transport processes. However in the light the degradation and conversion of starch are blocked. In pulse chase experiments with wild type plants and starchless mutants pgm or adg1 of arabidopsis an increase of starch radioactivity during chase in nonradioactive medium in the light was detected. These findings suggest that starch was additionally synthesized from labeled cytosolic soluble photosynthates, preferentially from sucrose. Radiogasometric studies of gas exchange have revealed that sucrose is consumed also in photorespiratory decarboxylations. To be involved in photorespiration the products of sucrose degradation must be transported from cytosol into chloroplast. We presume that derived from sucrose hexoses are transported into chloroplast by hexose transporter and phosphorylated there in hexokinase reaction. The phosphorylated hexoses may be consumed either for additional synthesis of starch or incorporated into the reductive pentose phosphate cycle and, via this cycle, into the glycolate cycle. (author)

  6. The vacuolar channel VvALMT9 mediates malate and tartrate accumulation in berries of Vitis vinifera.

    Science.gov (United States)

    De Angeli, Alexis; Baetz, Ulrike; Francisco, Rita; Zhang, Jingbo; Chaves, Maria Manuela; Regalado, Ana

    2013-08-01

    Vitis vinifera L. represents an economically important fruit species. Grape and wine flavour is made from a complex set of compounds. The acidity of berries is a major parameter in determining grape berry quality for wine making and fruit consumption. Despite the importance of malic and tartaric acid (TA) storage and transport for grape berry acidity, no vacuolar transporter for malate or tartrate has been identified so far. Some members of the aluminium-activated malate transporter (ALMT) anion channel family from Arabidopsis thaliana have been shown to be involved in mediating malate fluxes across the tonoplast. Therefore, we hypothesised that a homologue of these channels could have a similar role in V. vinifera grape berries. We identified homologues of the Arabidopsis vacuolar anion channel AtALMT9 through a TBLASTX search on the V. vinifera genome database. We cloned the closest homologue of AtALMT9 from grape berry cDNA and designated it VvALMT9. The expression profile revealed that VvALMT9 is constitutively expressed in berry mesocarp tissue and that its transcription level increases during fruit maturation. Moreover, we found that VvALMT9 is targeted to the vacuolar membrane. Using patch-clamp analysis, we could show that, besides malate, VvALMT9 mediates tartrate currents which are higher than in its Arabidopsis homologue. In summary, in the present study we provide evidence that VvALMT9 is a vacuolar malate channel expressed in grape berries. Interestingly, in V. vinifera, a tartrate-producing plant, the permeability of the channel is apparently adjusted to TA.

  7. Amino Acid Availability Modulates Vacuolar H+-ATPase Assembly*

    Science.gov (United States)

    Stransky, Laura A.; Forgac, Michael

    2015-01-01

    The vacuolar H+-ATPase (V-ATPase) is an ATP-dependent proton pump composed of a peripheral ATPase domain (V1) and a membrane-integral proton-translocating domain (V0) and is involved in many normal and disease processes. An important mechanism of regulating V-ATPase activity is reversible assembly of the V1 and V0 domains. Increased assembly in mammalian cells occurs under various conditions and has been shown to involve PI3K. The V-ATPase is necessary for amino acid-induced activation of mechanistic target of rapamycin complex 1 (mTORC1), which is important in controlling cell growth in response to nutrient availability and growth signals. The V-ATPase undergoes amino acid-dependent interactions with the Ragulator complex, which is involved in recruitment of mTORC1 to the lysosomal membrane during amino acid sensing. We hypothesized that changes in the V-ATPase/Ragulator interaction might involve amino acid-dependent changes in V-ATPase assembly. To test this, we measured V-ATPase assembly by cell fractionation in HEK293T cells treated with and without amino acids. V-ATPase assembly increases upon amino acid starvation, and this effect is reversed upon readdition of amino acids. Lysosomes from amino acid-starved cells possess greater V-ATPase-dependent proton transport, indicating that assembled pumps are catalytically active. Amino acid-dependent changes in both V-ATPase assembly and activity are independent of PI3K and mTORC1 activity, indicating the involvement of signaling pathways distinct from those implicated previously in controlling assembly. By contrast, lysosomal neutralization blocks the amino acid-dependent change in assembly and reactivation of mTORC1 after amino acid starvation. These results identify an important new stimulus for controlling V-ATPase assembly. PMID:26378229

  8. Autoactivation of proteinase A initiates activation of yeast vacuolar zymogens

    DEFF Research Database (Denmark)

    van den Hazel, H B; Kielland-Brandt, Morten; Winther, Jakob R.

    1992-01-01

    The Saccharomyces cerevisiae PEP4 gene encodes proteinase A, an aspartyl protease. pep4 mutants are defective in the activation of many vacuolar hydrolases, including proteinase B. We have expressed a pep4 mutation which directs the accumulation of pro-proteinase A with a defective active site. Co...

  9. RNAi-based silencing of genes encoding the vacuolar- ATPase ...

    African Journals Online (AJOL)

    RNAi-based silencing of genes encoding the vacuolar- ATPase subunits a and c in pink bollworm (Pectinophora gossypiella). Ahmed M. A. Mohammed. Abstract. RNA interference is a post- transcriptional gene regulation mechanism that is predominantly found in eukaryotic organisms. RNAi demonstrated a successful ...

  10. Multiple pathways for vacuolar sorting of yeast proteinase A

    DEFF Research Database (Denmark)

    Westphal, V; Marcusson, E G; Winther, Jakob R.

    1996-01-01

    The sorting of the yeast proteases proteinase A and carboxypeptidase Y to the vacuole is a saturable, receptor-mediated process. Information sufficient for vacuolar sorting of the normally secreted protein invertase has in fusion constructs previously been found to reside in the propeptide...

  11. Abscisic acid induction of vacuolar H+-ATPase activity in mesembryanthemum crystallinum is developmentally regulated

    Science.gov (United States)

    Barkla; Vera-Estrella; Maldonado-Gama; Pantoja

    1999-07-01

    Abscisic acid (ABA) has been implicated as a key component in water-deficit-induced responses, including those triggered by drought, NaCl, and low- temperature stress. In this study a role for ABA in mediating the NaCl-stress-induced increases in tonoplast H+-translocating ATPase (V-ATPase) and Na+/H+ antiport activity in Mesembryanthemum crystallinum, leading to vacuolar Na+ sequestration, were investigated. NaCl or ABA treatment of adult M. crystallinum plants induced V-ATPase H+ transport activity, and when applied in combination, an additive effect on V-ATPase stimulation was observed. In contrast, treatment of juvenile plants with ABA did not induce V-ATPase activity, whereas NaCl treatment resulted in a similar response to that observed in adult plants. Na+/H+ antiport activity was induced in both juvenile and adult plants by NaCl, but ABA had no effect at either developmental stage. Results indicate that ABA-induced changes in V-ATPase activity are dependent on the plant reaching its adult phase, whereas NaCl-induced increases in V-ATPase and Na+/H+ antiport activity are independent of plant age. This suggests that ABA-induced V-ATPase activity may be linked to the stress-induced, developmentally programmed switch from C3 metabolism to Crassulacean acid metabolism in adult plants, whereas, vacuolar Na+ sequestration, mediated by the V-ATPase and Na+/H+ antiport, is regulated through ABA-independent pathways.

  12. AtHMA3, a P1B-ATPase allowing Cd/Zn/Co/Pb vacuolar storage in Arabidopsis.

    Science.gov (United States)

    Morel, Mélanie; Crouzet, Jérôme; Gravot, Antoine; Auroy, Pascaline; Leonhardt, Nathalie; Vavasseur, Alain; Richaud, Pierre

    2009-02-01

    The Arabidopsis (Arabidopsis thaliana) Heavy Metal Associated3 (AtHMA3) protein belongs to the P1B-2 subgroup of the P-type ATPase family, which is involved in heavy metal transport. In a previous study, we have shown, using heterologous expression in the yeast Saccharomyces cerevisiae, that in the presence of toxic metals, AtHMA3 was able to phenotypically complement the cadmium/lead (Cd/Pb)-hypersensitive strain ycf1 but not the zinc (Zn)-hypersensitive strain zrc1. In this study, we demonstrate that AtHMA3 in planta is located in the vacuolar membrane, with a high expression level in guard cells, hydathodes, vascular tissues, and the root apex. Confocal imaging in the presence of the Zn/Cd fluorescent probe BTC-5N revealed that AtHMA3 participates in the vacuolar storage of Cd. A T-DNA insertional mutant was found more sensitive to Zn and Cd. Conversely, ectopic overexpression of AtHMA3 improved plant tolerance to Cd, cobalt, Pb, and Zn; Cd accumulation increased by about 2- to 3-fold in plants overexpressing AtHMA3 compared with wild-type plants. Thus, AtHMA3 likely plays a role in the detoxification of biological (Zn) and nonbiological (Cd, cobalt, and Pb) heavy metals by participating in their vacuolar sequestration, an original function for a P1B-2 ATPase in a multicellular eukaryote.

  13. Sucrose compared with artificial sweeteners

    DEFF Research Database (Denmark)

    Sørensen, Lone Brinkmann; Vasilaras, Tatjana H; Astrup, Arne

    2014-01-01

    There is a lack of appetite studies in free-living subjects supplying the habitual diet with either sucrose or artificially sweetened beverages and foods. Furthermore, the focus of artificial sweeteners has only been on the energy intake (EI) side of the energy-balance equation. The data are from...

  14. SYNTHESIS OF HYDROXYMETHYLFURFURAL FROM SUCROSE ...

    African Journals Online (AJOL)

    The synthesis of 5-hydroxymethylfurfural (HMF) from sucrose was investigated in the ... It was concluded that IL 1-(3-sulfonic acid)-propyl-3- ... imidazolium chloride was also used as both solvent and catalyst for the reactions of fructose and.

  15. Sucrose ingestion causes opioid analgesia

    Directory of Open Access Journals (Sweden)

    F.N. Segato

    1997-08-01

    Full Text Available The intake of saccharin solutions for relatively long periods of time causes analgesia in rats, as measured in the hot-plate test, an experimental procedure involving supraspinal components. In order to investigate the effects of sweet substance intake on pain modulation using a different model, male albino Wistar rats weighing 180-200 g received either tap water or sucrose solutions (250 g/l for 1 day or 14 days as their only source of liquid. Each rat consumed an average of 15.6 g sucrose/day. Their tail withdrawal latencies in the tail-flick test (probably a spinal reflex were measured immediately before and after this treatment. An analgesia index was calculated from the withdrawal latencies before and after treatment. The indexes (mean ± SEM, N = 12 for the groups receiving tap water for 1 day or 14 days, and sucrose solution for 1 day or 14 days were 0.09 ± 0.04, 0.10 ± 0.05, 0.15 ± 0.08 and 0.49 ± 0.07, respectively. One-way ANOVA indicated a significant difference (F(3,47 = 9.521, P<0.001 and the Tukey multiple comparison test (P<0.05 showed that the analgesia index of the 14-day sucrose-treated animals differed from all other groups. Naloxone-treated rats (N = 7 receiving sucrose exhibited an analgesia index of 0.20 ± 0.10 while rats receiving only sucrose (N = 7 had an index of 0.68 ± 0.11 (t = 0.254, 10 degrees of freedom, P<0.03. This result indicates that the analgesic effect of sucrose depends on the time during which the solution is consumed and extends the analgesic effects of sweet substance intake, such as saccharin, to a model other than the hot-plate test, with similar results. Endogenous opioids may be involved in the central regulation of the sweet substance-produced analgesia.

  16. Biosynthesis of sucrose and mannitol as a function of leaf age in celery (Apium graveolens L. )

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.M.; Fellman, J.K.; Loescher, W.H.

    1988-01-01

    In celery (Apium graveolens L.), the two major translocated carbohydrates are sucrose and the acyclic polyol mannitol. Their metabolism, however, is different and their specific functions are uncertain. To compare their roles in carbon partitioning and sink-source transitions, developmental changes in /sup 14/CO/sub 2/ labeling, pool sizes, and key enzyme activities in leaf tissues were examined. The proportion of label in mannitol increased dramatically with leaf maturation whereas that in sucrose remained fairly constant. Mannitol content, however, was high in all leaves and sucrose content increased as leaves developed. Activities of mannose-6-P reductase, cytoplasmic and chloroplastic fructose-1,6-bis-phosphatases, sucrose phosphate synthase, and sucrose synthase increased with leaf maturation and decreased as leaves senesced. Ribulose bisphosphate carboxylase and nonreversible glyceraldehyde-3-P dehydrogenase activities rose as leaves developed but did not decrease. Thus, sucrose is produced in all photosynthetically active leaves whereas mannitol is synthesized primarily in mature leaves and stored in all leaves. Onset of sucrose export in celery may result from sucrose accumulation in expanding leaves, but mannitol export is clearly unrelated to mannitol concentration. Mannitol export, however, appears to coincide with increased mannitol biosynthesis. Although mannitol and sucrose arise from a common precursor in celery, subsequent metabolism and transport must be regulated separately.

  17. X-ray diffraction studies of sucrose and sucrose irradiated with γ-radiation

    International Nuclear Information System (INIS)

    Prasad, Mahendra

    1981-01-01

    In order to understand and solve numerous problems related to sugar quality and its storage life, X-ray diffraction studies of sucrose and sucrose irradiated with γ-radiation have been made. It is observed that the interplanar spacing 'd' in irradiated sucrose is reduced indicating the partial damage of sucrose lattice. (author)

  18. Differential compartmentation of sucrose and gentianose in the cytosol and vacuoles of storage root protoplasts from Gentiana Lutea L.

    Science.gov (United States)

    Keller, F; Wiemken, A

    1982-12-01

    The storage roots of perennial Gentiana lutea L.plants contain several sugars. The predominant carbohydrate reserve is gentianose (β-D-glucopyranosyl-(1 → 6)-α-D-glucopyranosyl-(1 ↔ 2)-β-D-fructofuranoside). Vacuoles were isolated from root protoplasts and purified through a betaine density gradient. The yield was about 75%. Gentianose and gentiobiose were localized to 100% in the vacuoles, fructose and glucose to about 80%, and sucrose to only about 50%. Taking the volumes of the vacuolar and extravacuolar (cytosolic) compartments into account it is inferred that gentianose is located exclusively in the vacuoles, whilst sucrose is much more concentrated in the cytosol where it may play a role as a cryoprotectant. The concentration of fructose and glucose appeared to be similar on both sides of the tonoplast.

  19. Vacuolar myelinopathy in waterfowl from a North Carolina impoundment

    Science.gov (United States)

    Augspurger, T.; Fischer, John R.; Thomas, Nancy; Sileo, L.; Brannian, Roger E.; Miller, Kimberli J.; Rocke, Tonie E.

    2003-01-01

    Vacuolar myelinopathy was confirmed by light and electron microscopic examination of mallards (Anas platyrhynchos), ring-necked ducks (Aythya collaris), and buffleheads (Bucephala albeola) collected during an epizootic at Lake Surf in central North Carolina (USA) between November 1998 and February 1999. Clinical signs of affected birds were consistent with central nervous system impairment of motor function (incoordination, abnormal movement and posture, weakness, paralysis). This is the first report of this disease in wild waterfowl (Anseriformes).Aug

  20. Magnetostructural study of iron sucrose

    International Nuclear Information System (INIS)

    Gutierrez, Lucia; Puerto Morales, Maria del; Jose Lazaro, Francisco

    2005-01-01

    Magnetic and structural analyses have been performed on an iron sucrose complex used as a haematinic agent. The system contains two-line ferrihydrite particles of about 5 nm that are superparamagnetic above approximately 50 K. The observed low-temperature magnetic dynamics of this compound is closer to simple models than in the case of other iron-containing drugs for intravenous use like iron dextran

  1. Vacuolar processing enzyme in plant programmed cell death

    Directory of Open Access Journals (Sweden)

    Noriyuki eHatsugai

    2015-04-01

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

  2. Cytokine expression of macrophages in HIV-1-associated vacuolar myelopathy.

    Science.gov (United States)

    Tyor, W R; Glass, J D; Baumrind, N; McArthur, J C; Griffin, J W; Becker, P S; Griffin, D E

    1993-05-01

    Macrophages are frequently present within the periaxonal and intramyelinic vacuoles that are located primarily in the posterior and lateral funiculi of the thoracic spinal cord in HIV-associated vacuolar myelopathy. But the role of these macrophages in the formation of the vacuoles is unclear. One hypothesis is that cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF)-alpha, are produced locally by macrophages and have toxic effects on myelin or oligodendrocytes. The resulting myelin damage eventually culminates in the removal of myelin by macrophages and vacuole formation. We studied thoracic spinal cord specimens taken at autopsy from HIV-positive (+) and HIV-negative individuals. The predominant mononuclear cells present in HIV+ spinal cords are macrophages. They are located primarily in the posterior and lateral funiculi regardless of the presence or absence of vacuolar myelopathy. Macrophages and microglia are more frequent in HIV+ than HIV-negative individuals and these cells frequently stain for class I and class II antigens, IL-1, and TNF-alpha. Activated macrophages positive for IL-1 and TNF-alpha are great increased in the posterior and lateral funiculi of HIV+ individuals with and without vacuolar myelopathy, suggesting they are present prior to the development of vacuoles. Cytokines, such as TNF-alpha, may be toxic for myelin or oligodendrocytes, leading to myelin damage and removal by macrophages and vacuole formation.

  3. Transcriptome Analysis of Sucrose Metabolism during Bulb Swelling and Development in Onion (Allium cepa L.

    Directory of Open Access Journals (Sweden)

    Yi Liang

    2016-09-01

    Full Text Available Allium cepa L. is a widely cultivated and economically significant vegetable crop worldwide, with beneficial dietary and health-related properties, but its sucrose metabolism is still poorly understood. To analyze sucrose metabolism during bulb swelling, and the development of sweet taste in onion, a global transcriptome profile of onion bulbs was undertaken at three different developmental stages, using RNA-seq. A total of 79,376 unigenes, with a mean length of 678 bp, was obtained. In total, 7% of annotated Clusters of Orthologous Groups (COG were involved in carbohydrate transport and metabolism. In the Kyoto Encyclopedia of Genes and Genomes (KEGG database, starch and sucrose metabolism (147, 2.40% constituted the primary metabolism pathway in the integrated library. The expression of sucrose transporter genes was greatest during the early-swelling stage, suggesting that sucrose transporters participated in sucrose metabolism mainly at an early stage of bulb development. A gene-expression analysis of the key enzymes of sucrose metabolism suggested that sucrose synthase, cell wall invertase and invertase were all likely to participate in the hydrolysis of sucrose, generating glucose and fructose. In addition, trehalose was hydrolyzed to two molecules of glucose by trehalase. From 15 to 40 days after swelling (DAS, both the glucose and fructose contents of bulbs increased, whereas the sucrose content decreased. The growth rate between 15 and 30 DAS was slower than that between 30 and 40 DAS, suggesting that the latter was a period of rapid expansion. The dataset generated by our transcriptome profiling will provide valuable information for further research.

  4. Toxoplasma gondii sequesters lysosomes from mammalian hosts in the vacuolar space.

    Science.gov (United States)

    Coppens, Isabelle; Dunn, Joe Dan; Romano, Julia D; Pypaert, Marc; Zhang, Hui; Boothroyd, John C; Joiner, Keith A

    2006-04-21

    The intracellular compartment harboring Toxoplasma gondii satisfies the parasite's nutritional needs for rapid growth in mammalian cells. We demonstrate that the parasitophorous vacuole (PV) of T. gondii accumulates material coming from the host mammalian cell via the exploitation of the host endo-lysosomal system. The parasite actively recruits host microtubules, resulting in selective attraction of endo-lysosomes to the PV. Microtubule-based invaginations of the PV membrane serve as conduits for the delivery of host endo-lysosomes within the PV. These tubular conduits are decorated by a parasite coat, including the tubulogenic protein GRA7, which acts like a garrote that sequesters host endocytic organelles in the vacuolar space. These data define an unanticipated process allowing the parasite intimate and concentrated access to a diverse range of low molecular weight components produced by the endo-lysosomal system. More generally, they identify a unique mechanism for unidirectional transport and sequestration of host organelles.

  5. Uptake and intracellular fate of [14C]sucrose-insulin in perfused rat livers

    International Nuclear Information System (INIS)

    Surmacz, C.A.; Wert, J.J. Jr.; Ward, W.F.; Mortimore, G.E.

    1988-01-01

    Insulin was covalently linked to [ 14 C]sucrose by means of cyanuric chloride to provide a label that would remain entrapped within the vacuolar system. The uptake of the conjugate by the perfused rat liver was rapid, competitively inhibited by native insulin, and abolished by alkali denaturation. As assessed by its distribution on self-generating gradients of colloidal silica-povidone, label in lysosome-enriched samples of liver taken at different times after the addition of the conjugate moved progressively during 15 min from the plasma membrane into an intermediate peak and then to dense lysosomal fractions. After 30-60 min, the label had equilibrated throughout the lysosomal-vacuolar system. The initial movement from the plasma membrane to the intermediate peak occurred between 2 and 5 min. Because label in the peak could be physically separated from the lysosomal marker, β-acetylglucosaminidase, by dispersing the sample through the gradient mixture before centrifugation rather than layering it, the authors concluded that the intermediate particles in question were not lysosomal in nature. On gel-filtration chromatography, label extracted from the intermediate peak did not move with insulin but rather as a broad band of lower molecular weight products, suggesting that insulin is subject to early proteolytic attack within a nonlysosomal compartment

  6. Uptake and intracellular fate of [14C]sucrose-insulin in perfused rat livers.

    Science.gov (United States)

    Surmacz, C A; Wert, J J; Ward, W F; Mortimore, G E

    1988-07-01

    Insulin was covalently linked to [14C]sucrose by means of cyanuric chloride to provide a label that would remain entrapped within the vacuolar system. The uptake of the conjugate by the perfused rat liver was rapid (half-life = 2.9 min), competitively inhibited by native insulin, and abolished by alkali denaturation. As assessed by its distribution on self-generating gradients of colloidal silica-povidone, label in lysosome-enriched samples of liver taken at different times after the addition of the conjugate moved progressively during 15 min from the plasma membrane into an intermediate peak and then to dense lysosomal fractions. After 30-60 min, the label had equilibrated throughout the lysosomal-vacuolar system. The initial movement from the plasma membrane to the intermediate peak occurred between 2 and 5 min. Because label in the peak could be physically separated from the lysosomal marker, beta-acetylglucosaminidase, by dispersing the sample through the gradient mixture before centrifugation rather than layering it, we concluded that the intermediate particles in question were not lysosomal in nature. On gel-filtration chromatography, label extracted from the intermediate peak did not move with insulin but rather as a broad band of lower molecular weight products, suggesting that insulin is subject to early proteolytic attack within a nonlysosomal compartment.

  7. Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis.

    Science.gov (United States)

    Ribeiro, Rafael V; Machado, Eduardo C; Magalhães Filho, José R; Lobo, Ana Karla M; Martins, Márcio O; Silveira, Joaquim A G; Yin, Xinyou; Struik, Paul C

    2017-01-01

    Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (g s ), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory effect of exogenous sucrose on photosynthesis. Source-sink relationship was perturbed in two sugarcane cultivars by imposing partial darkness, spraying a sucrose solution (50mM) and their combination. Five days after the onset of the treatments, the maximum Rubisco carboxylation rate (V cmax ) and the initial slope of A-C i curve (k) were estimated by measuring leaf gas exchange and chlorophyll fluorescence. Photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in V cmax , k, g s and ATP production driven by electron transport (J atp ). Photosynthesis of plants subjected to the combination of partial darkness and sucrose spraying was similar to photosynthesis of reference plants for both genotypes. Significant increases in V cmax , g s and J atp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Cadmium induces changes in sucrose partitioning, invertase activities, and membrane functionality in roots of Rangpur lime (Citrus limonia L. Osbeck).

    Science.gov (United States)

    Podazza, G; Rosa, M; González, J A; Hilal, M; Prado, F E

    2006-09-01

    Cadmium (Cd) uptake effects on sucrose content, invertase activities, and plasma membrane functionality were investigated in Rangpur lime roots ( CITRUS LIMONIA L. Osbeck). Cadmium accumulation was significant in roots but not in shoots and leaves. Cadmium produced significant reduction in roots DW and increment in WC. Leaves and shoots did not show significant differences on both parameters. Sucrose content was higher in control roots than in Cd-exposed ones. Apoplastic sucrose content was much higher in Cd-exposed roots than in control ones. Cd-exposed roots showed a significant decrease in both cell wall-bound and cytoplasmic (neutral) invertase activities; while the vacuolar isoform did not show any change. Alterations in lipid composition and membrane fluidity of Cd-exposed roots were also observed. In Cd-exposed roots phospholipid and glycolipid contents decreased about 50 %, while sterols content was reduced about 22 %. Proton extrusion was inhibited by Cd. Lipid peroxidation and proton extrusion inhibition were also detected by histochemical analysis. This work's findings demonstrate that Cd affects sucrose partitioning and invertase activities in apoplastic and symplastic regions in Rangpur lime roots as well as the plasma membrane functionality and H (+)-ATPase activity.

  9. Accumulation of sucrose in irradiated agricultural products

    International Nuclear Information System (INIS)

    Hayashi, T.

    1986-01-01

    Irradiation of agricultural products with ionizing radiation causes various physiological changes and one of the interesting phenomena is the increase of sucrose in irradiated potatoes. The relationship, however, between sucrose content and irradiation dose was not clarified. The author has made the relationship clear and found out that the sucrose content once enhanced by a high dose of irradiation does not lower during storage for a long period. It has been found that the sucrose accumulation caused by irradiation occurred in sweet potatoes and chestnuts as well as potatoes. In this article the effect of gamma-irradiation on the sucrose content of potato tubers, sweet potato roots and chestnuts will be reviewed and the mechanism of this sucrose accumulation will be discussed

  10. Accumulation of sucrose in irradiated agricultural products

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, T. [National Food Research Inst., Tsukuba, Ibaraki (Japan)

    1986-03-15

    Irradiation of agricultural products with ionizing radiation causes various physiological changes and one of the interesting phenomena is the increase of sucrose in irradiated potatoes. The relationship, however, between sucrose content and irradiation dose was not clarified. The author has made the relationship clear and found out that the sucrose content once enhanced by a high dose of irradiation does not lower during storage for a long period. It has been found that the sucrose accumulation caused by irradiation occurred in sweet potatoes and chestnuts as well as potatoes. In this article the effect of gamma-irradiation on the sucrose content of potato tubers, sweet potato roots and chestnuts will be reviewed and the mechanism of this sucrose accumulation will be discussed.

  11. Role of maltase in the utilization of sucrose by Candida albicans.

    Science.gov (United States)

    Williamson, P R; Huber, M A; Bennett, J E

    1993-01-01

    Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-->4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase. Images Figure 1 Figure 2 Figure 4 PMID:8489504

  12. Functional size of vacuolar H+ pumps: Estimates from radiation inactivation studies

    International Nuclear Information System (INIS)

    Sarafian, V.; Poole, R.J.

    1991-01-01

    The PPase and the ATPase from red beet (Beta vulgaris) vacuolar membranes were subjected to radiation inactivation by a 60 Co source in both the native tonoplast and detergent-solubilized states, in order to determine their target molecular sizes. Analysis of the residual phosphohydrolytic and proton transport activities, after exposure to varying doses of radiation, yielded exponential relationships between the activities and radiation doses. The deduced target molecular sizes for PPase activity in native and solubilized membranes were 125kD and 259kD respectively and 327kD for H + -transport. This suggests that the minimum number of subunits of 67kD for PPi hydrolysis is two in the native state and four after Triton X-100 solubilization. At least four subunits would be required for H + -translocation. Analysis of the ATPase inactivation patterns revealed target sizes of 384kD and 495kD for ATP hydrolysis in native and solubilized tonoplast respectively and 430kD for H + -transport. These results suggest that the minimum size for hydrolytic or transport functions is relatively constant for the ATPase

  13. Abscisic Acid Induction of Vacuolar H+-ATPase Activity in Mesembryanthemum crystallinum Is Developmentally Regulated1

    Science.gov (United States)

    Barkla, Bronwyn J.; Vera-Estrella, Rosario; Maldonado-Gama, Minerva; Pantoja, Omar

    1999-01-01

    Abscisic acid (ABA) has been implicated as a key component in water-deficit-induced responses, including those triggered by drought, NaCl, and low- temperature stress. In this study a role for ABA in mediating the NaCl-stress-induced increases in tonoplast H+-translocating ATPase (V-ATPase) and Na+/H+ antiport activity in Mesembryanthemum crystallinum, leading to vacuolar Na+ sequestration, were investigated. NaCl or ABA treatment of adult M. crystallinum plants induced V-ATPase H+ transport activity, and when applied in combination, an additive effect on V-ATPase stimulation was observed. In contrast, treatment of juvenile plants with ABA did not induce V-ATPase activity, whereas NaCl treatment resulted in a similar response to that observed in adult plants. Na+/H+ antiport activity was induced in both juvenile and adult plants by NaCl, but ABA had no effect at either developmental stage. Results indicate that ABA-induced changes in V-ATPase activity are dependent on the plant reaching its adult phase, whereas NaCl-induced increases in V-ATPase and Na+/H+ antiport activity are independent of plant age. This suggests that ABA-induced V-ATPase activity may be linked to the stress-induced, developmentally programmed switch from C3 metabolism to Crassulacean acid metabolism in adult plants, whereas, vacuolar Na+ sequestration, mediated by the V-ATPase and Na+/H+ antiport, is regulated through ABA-independent pathways. PMID:10398716

  14. Production of 16% ethanol from 35% sucrose

    International Nuclear Information System (INIS)

    Breisha, Gaber Z.

    2010-01-01

    A strain of Saccharomyces cerevisiae, which showed marked fermentation activity, ethanol and temperature tolerance and good flocculation ability, was selected for ethanol production. A stuck fermentation occurred at sucrose concentration of 25%. Increasing the yeast inoculum volume from 3% to 6% showed positive effects on fermentation from 25% sucrose. The ratio of added nitrogen to sucrose, which gave the best results (for the selected yeast strain), was determined. It was concluded that this ratio (nitrogen as ammonium sulphate at a rate of 5 mg g -1 of consumed sucrose) is constant at various sugar concentrations. Addition of nitrogen at this ratio produced 11.55% ethanol with complete consumption of 25% sucrose after 48 h of fermentation. However fermentation of 30% sucrose at the above optimum conditions was not complete. Addition of yeast extract at a level of 6 g l -1 together with thiamine at a level of 0.2 g l -1 led to complete utilization of 30% sucrose with resultant 14% ethanol production. However the selected yeast strain was not able to ferment 35% sucrose at the same optimum conditions. Addition of air at a rate of 150 dm 3 min -1 m 3 of reactor volume during the first 12 h of fermentation led to complete consumption of 35% sucrose and 16% ethanol was produced. This was approximately the theoretical maximum for ethanol production.

  15. Production of 16% ethanol from 35% sucrose

    Energy Technology Data Exchange (ETDEWEB)

    Breisha, Gaber Z. [Department of Agricultural Microbiology, Faculty of Agriculture, Minia University, Minia (Egypt)

    2010-08-15

    A strain of Saccharomyces cerevisiae, which showed marked fermentation activity, ethanol and temperature tolerance and good flocculation ability, was selected for ethanol production. A stuck fermentation occurred at sucrose concentration of 25%. Increasing the yeast inoculum volume from 3% to 6% showed positive effects on fermentation from 25% sucrose. The ratio of added nitrogen to sucrose, which gave the best results (for the selected yeast strain), was determined. It was concluded that this ratio (nitrogen as ammonium sulphate at a rate of 5 mg g{sup -1} of consumed sucrose) is constant at various sugar concentrations. Addition of nitrogen at this ratio produced 11.55% ethanol with complete consumption of 25% sucrose after 48 h of fermentation. However fermentation of 30% sucrose at the above optimum conditions was not complete. Addition of yeast extract at a level of 6 g l{sup -1} together with thiamine at a level of 0.2 g l{sup -1} led to complete utilization of 30% sucrose with resultant 14% ethanol production. However the selected yeast strain was not able to ferment 35% sucrose at the same optimum conditions. Addition of air at a rate of 150 dm{sup 3} min{sup -1} m{sup 3} of reactor volume during the first 12 h of fermentation led to complete consumption of 35% sucrose and 16% ethanol was produced. This was approximately the theoretical maximum for ethanol production. (author)

  16. The effect of ethylene on sucrose-uptake by senescing petunia flowers.

    OpenAIRE

    2008-01-01

    The influence of sucrose as an important factor in the vase-life of cut flowers has been dually noted. Sucrose is actively transported across the cell membrane via a symport system and the membrane-imbedded ATPase enzyme generates the required energy and proton gradient for the process. The activity of this enzyme decreases during the senescence of Petunia petals, concomitant with a decrease in sucrose-uptake in the post-climacteric phase. However, ATP does not appear to be limiting, indicati...

  17. THE TONOPLAST TRANSPORT SYSTEMS OF PLANT VACUOLES AND THEIR POTENTIAL APPLICATION IN BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    S. V. Isayenkov

    2013-06-01

    Full Text Available The pivotal role of plant vacuoles in plant survival was discussed in the review. Particularly, the providing of cellular turgor, accumulation of inorganic osmolytes and nutrients are the primary tasks of these cellular organelles. The main mechanisms of tonoplast transport systems were described. The known transport pathways of minerals, heavy metals, vitamins and other organic compounds were classified and outlined. The main systems of membrane vacuolar transport were reviewed. The outline of the physiological functions and features of vacuolar membrane transport proteins were performed. The physiological role of transport of minerals, nutrients and other compounds into vacuoles were discussed. This article reviews the main types of plant vacuoles and their functional role in plant cell. Current state and progress in vacuolar transport research was outlined. The examples of application for rinciples and mechanisms of vacuolar membrane transport in plant biotechnology were iven. The perspectives and approaches in plant and food biotechnology concerning transport and physiology of vacuoles are discussed.

  18. Vacuolar morphology of Saccharomyces cerevisiae during the process of wine making and Japanese sake brewing.

    Science.gov (United States)

    Izawa, Shingo; Ikeda, Kayo; Miki, Takeo; Wakai, Yoshinori; Inoue, Yoshiharu

    2010-09-01

    Although ethanol and osmotic stress affect the vacuolar morphology of Saccharomyces cerevisiae, little information is available about changes in vacuolar morphology during the processes of wine making and Japanese sake (rice wine) brewing. Here, we elucidated changes in the morphology of yeast vacuoles using Zrc1p-GFP, a vacuolar membrane protein, so as to better understand yeast physiology during the brewing process. Wine yeast cells (OC-2 and EC1118) contained highly fragmented vacuoles in the sake mash (moromi) as well as in the grape must. Although sake yeast cells (Kyokai no. 9 and no. 10) also contained highly fragmented vacuoles during the wine-making process, they showed quite a distinct vacuolar morphology during sake brewing. Since the environment surrounding sake yeast cells in the sake mash did not differ much from that surrounding wine yeast cells, the difference in vacuolar morphology during sake brewing between wine yeast and sake yeast was likely caused by innate characters.

  19. Proton pump inhibitors as anti vacuolar-ATPases drugs: a novel anticancer strategy.

    Science.gov (United States)

    Spugnini, Enrico P; Citro, Gennaro; Fais, Stefano

    2010-05-08

    The vacuolar ATPases are ATP-dependent proton pumps whose functions include the acidification of intracellular compartments and the extrusion of protons through the cell cytoplasmic membrane. These pumps play a pivotal role in the regulation of cell pH in normal cells and, to a much greater extent, in tumor cells. In fact, the glucose metabolism in hypoxic conditions by the neoplasms leads to an intercellular pH drift towards acidity. The acid microenvironment is modulated through the over-expression of H+ transporters that are also involved in tumor progression, invasiveness, distant spread and chemoresistance. Several strategies to block/downmodulate the efficiency of these transporters are currently being investigated. Among them, proton pump inhibitors have shown to successfully block the H+ transporters in vitro and in vivo, leading to apoptotic death. Furthermore, their action seems to synergize with conventional chemotherapy protocols, leading to chemosensitization and reversal of chemoresistance. Aim of this article is to critically revise the current knowledge of this cellular machinery and to summarize the therapeutic strategies developed to counter this mechanism.

  20. Proton pump inhibitors as anti vacuolar-ATPases drugs: a novel anticancer strategy

    Directory of Open Access Journals (Sweden)

    Fais Stefano

    2010-05-01

    Full Text Available Abstract The vacuolar ATPases are ATP-dependent proton pumps whose functions include the acidification of intracellular compartments and the extrusion of protons through the cell cytoplasmic membrane. These pumps play a pivotal role in the regulation of cell pH in normal cells and, to a much greater extent, in tumor cells. In fact, the glucose metabolism in hypoxic conditions by the neoplasms leads to an intercellular pH drift towards acidity. The acid microenvironment is modulated through the over-expression of H+ transporters that are also involved in tumor progression, invasiveness, distant spread and chemoresistance. Several strategies to block/downmodulate the efficiency of these transporters are currently being investigated. Among them, proton pump inhibitors have shown to successfully block the H+ transporters in vitro and in vivo, leading to apoptotic death. Furthermore, their action seems to synergize with conventional chemotherapy protocols, leading to chemosensitization and reversal of chemoresistance. Aim of this article is to critically revise the current knowledge of this cellular machinery and to summarize the therapeutic strategies developed to counter this mechanism.

  1. A pivotal role of vacuolar H(+)-ATPase in regulation of lipid production in Phaeodactylum tricornutum.

    Science.gov (United States)

    Zhang, Huiying; Zeng, Rensen; Chen, Daoyi; Liu, Jian

    2016-08-08

    Microalgal lipids have been considered as a promising source for biodiesel production. Alkaline pH can induce neutral lipid accumulation in microalgae cells. However, whether and how proton pumps, especially vacuolar H(+)-ATPase (V-ATPase), function in these processes is not well known. In this study, we treated Phaeodactylum tricornutum with V-ATPase specific inhibitor bafilomycin A1 (BFA1) to determine its role in lipid production. Firstly, V-ATPase activity was increased in the latter phase of microalgae growth. BFA1 treatment decreased the cell density and lipid contents. Further analysis showed that BFA1 treatment reduced the number and size of oil bodies. GC-MS analysis showed that lipid components were not affected by BFA1 treatment. Intracellular pH was decreased and nitrogen depletion was delayed after BFA1 treatment. RNA-Seq analysis showed that expression of genes involved in calcium signaling, sulfur metabolism, cell cycle, glycolysis, pentose phosphate pathway, porphyrin, chlorophyll metabolism and lipid catabolic metabolism were upregulated, while expression of genes involved in ion transmembrane transport, ubiquitin mediated proteolysis, SNARE interactions in vesicular transport, fatty acid biosynthesis were downregulated under BFA1 treatment. Our findings provided insights into the molecular mechanisms underlying lipid accumulation and the key genes involved in lipid metabolism in Phaeodactylum tricornutum in response to BFA1.

  2. [Sucrose reward promotes rats' motivation for cocaine].

    Science.gov (United States)

    Li, Yan-Qing; LE, Qiu-Min; Yu, Xiang-Chen; Ma, Lan; Wang, Fei-Fei

    2016-06-25

    Caloric diet, such as fat and sugar intake, has rewarding effects, and has been indicated to affect the responses to addictive substances in animal experiments. However, the possible association between sucrose reward and the motivation for addictive drugs remains to be elucidated. Thus, we carried out behavioral tests after sucrose self-administration training to determine the effects of sucrose experience on rats' motivation for cocaine, locomotor sensitivity to cocaine, basal locomotor activity, anxiety level, and associative learning ability. The sucrose-experienced (sucrose) group exhibited higher lever press, cocaine infusion and break point, as well as upshift of cocaine dose-response curve in cocaine self-administration test, as compared with the control (chow) group. Additionally, despite similar locomotor activity in open field test and comparable score in cocaine-induced conditioned place preference, the sucrose group showed higher cocaine-induced locomotor sensitivity as compared with the chow group. The anxiety level and the performance in vocal-cue induced fear memory were similar between these two groups in elevated plus maze and fear conditioning tests, respectively. Taken together, our work indicates that sucrose experience promotes the rats' motivation for cocaine.

  3. IDENTIFICATION AND CHARACTERIZATION OF THE SUCROSE SYNTHASE 2 GENE (Sus2 IN DURUM WHEAT

    Directory of Open Access Journals (Sweden)

    Mariateresa eVolpicella

    2016-03-01

    Full Text Available Sucrose transport is the central system for the allocation of carbon resources in vascular plants. Sucrose synthase, which reversibly catalyzes sucrose synthesis and cleavage, represents a key enzyme in the control of the flow of carbon into starch biosynthesis. In the present study the genomic identification and characterization of the Sus2-2A and Sus2-2B genes coding for sucrose synthase in durum wheat (cultivars Ciccio and Svevo is reported. The genes were analyzed for their expression in different tissues and at different seed maturation stages, in four tetraploid wheat genotypes (Svevo, Ciccio, Primadur and 5-BIL42. The activity of the encoded proteins was evaluated by specific activity assays on endosperm extracts and their structure established by modelling approaches. The combined results of SUS2 expression and activity levels were then considered in the light of their possible involvement in starch yield.

  4. vph6 mutants of Saccharomyces cerevisiae require calcineurin for growth and are defective in vacuolar H(+)-ATPase assembly.

    Science.gov (United States)

    Hemenway, C S; Dolinski, K; Cardenas, M E; Hiller, M A; Jones, E W; Heitman, J

    1995-11-01

    We have characterized a Saccharomyces cerevisiae mutant strain that is hypersensitive to cyclosporin A (CsA) and FK506, immunosuppressants that inhibit calcineurin, a serine-threonine-specific phosphatase (PP2B). A single nuclear mutation, designated cev1 for calcineurin essential for viability, is responsible for the CsA-FK506-sensitive phenotype. The peptidyl-prolyl cis-trans isomerases cyclophilin A and FKBP12, respectively, mediate CsA and FK506 toxicity in the cev1 mutant strain. We demonstrate that cev1 is an allele of the VPH6 gene and that vph6 mutant strains fail to assemble the vacuolar H(+)-ATPase (V-ATPase). The VPH6 gene was mapped on chromosome VIII and is predicted to encode a 181-amino acid (21 kD) protein with no identity to other known proteins. We find that calcineurin is essential for viability in many mutant strains with defects in V-ATPase function or vacuolar acidification. In addition, we find that calcineurin modulates extracellular acidification in response to glucose, which we propose occurs via calcineurin regulation of the plasma membrane H(+)-ATPase PMA1. Taken together, our findings suggest calcineurin plays a general role in the regulation of cation transport and homeostasis.

  5. Vacuolar processing enzyme: an executor of plant cell death.

    Science.gov (United States)

    Hara-Nishimura, Ikuko; Hatsugai, Noriyuki; Nakaune, Satoru; Kuroyanagi, Miwa; Nishimura, Mikio

    2005-08-01

    Apoptotic cell death in animals is regulated by cysteine proteinases called caspases. Recently, vacuolar processing enzyme (VPE) was identified as a plant caspase. VPE deficiency prevents cell death during hypersensitive response and cell death of limited cell layers at the early stage of embryogenesis. Because plants do not have macrophages, dying cells must degrade their materials by themselves. VPE plays an essential role in the regulation of the lytic system of plants during the processes of defense and development. VPE is localized in the vacuoles, unlike animal caspases, which are localized in the cytosol. Thus, plants might have evolved a regulated cellular suicide strategy that, unlike animal apoptosis, is mediated by VPE and the vacuoles.

  6. Structural development of sucrose-sweetened and sucrose-free sponge cakes during baking.

    Science.gov (United States)

    Baeva, Marianna Rousseva; Terzieva, Vesselina Velichkova; Panchev, Ivan Nedelchev

    2003-06-01

    The influence of sucrose, wheat starch and sorbitol upon the heat- and mass-exchanging processes forming the structure of sponge cake was studied. Under the influence of wheat starch and sorbitol the structure of the sucrose-free sponge cake was formed at more uniform total moisture release. This process was done at lower temperatures and smoother change of the sponge cake height with respect to the sucrose-sweetened sponge cake. The porous and steady structure of both cakes was finally formed at identical time--between 18th and 19th minute, at the applied conditions for baking of each batter (metal pan with diameter 15.4 cm and depth 6.2 cm containing 300 g of batter and placed in an electric oven "Rahovetz-02", Bulgaria for 30 min at 180 degrees C). The water-losses at the end of baking (10.30% and 10.40% for the sucrose-sweetened cake and sucrose-free cake, respectively) and the final temperatures reached in the crumb central layers (96.6 degrees C and 96.3 degrees C for the sucrose-sweetened cake and sucrose-free cake, respectively) during baking of both samples were not statistically different. The addition of wheat starch and sorbitol in sucrose-free sponge cake lead to the statistically different values for the porosity (76.15% and 72.98%) and the volume (1014.17 cm3 and 984.25 cm3) of the sucrose-sweetened and sucrose-free sponge cakes, respectively. As a result, the sucrose-free sponge cake formed during baking had a more homogeneous and finer microstructure with respect to that ofthe sucrose-sweetened one.

  7. Regulation of transport processes across the tonoplast

    Science.gov (United States)

    Neuhaus, H. Ekkehard; Trentmann, Oliver

    2014-01-01

    In plants, the vacuole builds up the cellular turgor and represents an important component in cellular responses to diverse stress stimuli. Rapid volume changes of cells, particularly of motor cells, like guard cells, are caused by variation of osmolytes and consequently of the water contents in the vacuole. Moreover, directed solute uptake into or release out of the large central vacuole allows adaptation of cytosolic metabolite levels according to the current physiological requirements and specific cellular demands. Therefore, solute passage across the vacuolar membrane, the tonoplast, has to be tightly regulated. Important principles in vacuolar transport regulation are changes of tonoplast transport protein abundances by differential expression of genes or changes of their activities, e.g., due to post-translational modification or by interacting proteins. Because vacuolar transport is in most cases driven by an electro-chemical gradient altered activities of tonoplast proton pumps significantly influence vacuolar transport capacities. Intense studies on individual tonoplast proteins but also unbiased system biological approaches have provided important insights into the regulation of vacuolar transport. This short review refers to selected examples of tonoplast proteins and their regulation, with special focus on protein phosphorylation. PMID:25309559

  8. Sucrose, Its Proprieties and the New Sweeteners

    Directory of Open Access Journals (Sweden)

    Tatiana Monique Manhani

    2014-06-01

    Full Text Available The aims of this paper are to review the literature on sucrose, commonly known as table sugar; to report as it appeared in Brazil and in the world; to discuss the differences between crystal and refined sucrose; to show the harmful effects of overconsumption; and to list their main sweeteners. Sucrose appeared over 7000 years ago and since then it has actively participated in the creation of new forms of food consumption, in the development of societies and in the social and political relations. Carbohydrates are the main source of energy for the body and considering that they are present in different foods, their consumption in excess can cause diseases such as obesity and diabetes. The amount of processed products with sucrose in its composition is uncountable and overconsumption has caused concern in the medical field. The manufacture of sugar is a process that involves a series of operations to obtain the final product. There are several kinds of sucrose that are available according to its use (domestic and industrial. The sweeteners can be used to sweeten, and may replace sucrose. Some of these compounds are known as intense sweeteners, being used in very small quantities, are indicated to people who have a disorder in the metabolism of sugars (diabetics or consumers who are in search of products of low calorific value.

  9. Identification of small molecules that disrupt vacuolar function in the pathogen Candida albicans.

    Directory of Open Access Journals (Sweden)

    Helene Tournu

    Full Text Available The fungal vacuole is a large acidified organelle that performs a variety of cellular functions. At least a sub-set of these functions are crucial for pathogenic species of fungi, such as Candida albicans, to survive within and invade mammalian tissue as mutants with severe defects in vacuolar biogenesis are avirulent. We therefore sought to identify chemical probes that disrupt the normal function and/or integrity of the fungal vacuole to provide tools for the functional analysis of this organelle as well as potential experimental therapeutics. A convenient indicator of vacuolar integrity based upon the intracellular accumulation of an endogenously produced pigment was adapted to identify Vacuole Disrupting chemical Agents (VDAs. Several chemical libraries were screened and a set of 29 compounds demonstrated to reproducibly cause loss of pigmentation, including 9 azole antifungals, a statin and 3 NSAIDs. Quantitative analysis of vacuolar morphology revealed that (excluding the azoles a sub-set of 14 VDAs significantly alter vacuolar number, size and/or shape. Many C. albicans mutants with impaired vacuolar function are deficient in the formation of hyphal elements, a process essential for its pathogenicity. Accordingly, all 14 VDAs negatively impact C. albicans hyphal morphogenesis. Fungal selectivity was observed for approximately half of the VDA compounds identified, since they did not alter the morphology of the equivalent mammalian organelle, the lysosome. Collectively, these compounds comprise of a new collection of chemical probes that directly or indirectly perturb normal vacuolar function in C. albicans.

  10. Sucrose metabolic pathways in sweetgum and pecan seedlings

    Science.gov (United States)

    S.S. Sung; P.P. Kormanik; D.P. Xu; C.C. Black

    1989-01-01

    Sucrose metabolism and glycolysis were studied in one- to two-year-old seedlings of sweetgum (Liquidambar styraciflua L.) and pecan (Carya illinoinensis (Wangenh.) C. Koch). The sucrose synthase pathway was identified as the dominant sucrose metabolic activity in sucrose sink tissues such as terminal buds and the root cambial...

  11. Vacuolar biogenesis and aquaporin expression at early germination of broad bean seeds.

    Science.gov (United States)

    Novikova, Galina V; Tournaire-Roux, Colette; Sinkevich, Irina A; Lityagina, Snejana V; Maurel, Christophe; Obroucheva, Natalie

    2014-09-01

    A key event in seed germination is water uptake-mediated growth initiation in embryonic axes. Vicia faba var. minor (broad bean) seeds were used for studying cell growth, vacuolar biogenesis, expression and function of tonoplast water channel proteins (aquaporins) in embryonic axes during seed imbibition, radicle emergence and growth. Hypocotyl and radicle basal cells showed vacuole restoration from protein storage vacuoles, whereas de novo vacuole formation from provacuoles was observed in cells newly produced by root meristem. cDNA fragments of seven novel aquaporin isoforms including five Tonoplast Intrinsic Proteins (TIP) from three sub-types were amplified by PCR. The expression was probed using q-RT-PCR and when possible with isoform-specific antibodies. Decreased expression of TIP3s was associated to the transformation of protein storage vacuoles to vacuoles, whereas enhanced expression of a TIP2 homologue was closely linked to the fast cell elongation. Water channel functioning checked by inhibitory test with mercuric chloride showed closed water channels prior to growth initiation and active water transport into elongating cells. The data point to a crucial role of tonoplast aquaporins during germination, especially during growth of embryonic axes, due to accelerated water uptake and vacuole enlargement resulting in rapid cell elongation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. Regulatory assembly of the vacuolar proton pump VoV1-ATPase in yeast cells by FLIM-FRET

    Science.gov (United States)

    Ernst, Stefan; Batisse, Claire; Zarrabi, Nawid; Böttcher, Bettina; Börsch, Michael

    2010-02-01

    We investigate the reversible disassembly of VOV1-ATPase in life yeast cells by time resolved confocal FRET imaging. VOV1-ATPase in the vacuolar membrane pumps protons from the cytosol into the vacuole. VOV1-ATPase is a rotary biological nanomotor driven by ATP hydrolysis. The emerging proton gradient is used for secondary transport processes as well as for pH and Ca2+ homoeostasis in the cell. The activity of the VOV1-ATPase is regulated through assembly / disassembly processes. During starvation the two parts of VOV1-ATPase start to disassemble. This process is reversed after addition of glucose. The exact mechanisms are unknown. To follow the disassembly / reassembly in vivo we tagged two subunits C and E with different fluorescent proteins. Cellular distributions of C and E were monitored using a duty cycle-optimized alternating laser excitation scheme (DCO-ALEX) for time resolved confocal FRET-FLIM measurements.

  13. Structural rearrangements of sucrose phosphorylase from Bifidobacterium adolescentis during sucrose conversion

    DEFF Research Database (Denmark)

    Mirza, Osman; Henriksen, Lars Skov; Sprogøe, Desiree

    2006-01-01

    The reaction mechanism of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) was studied by site-directed mutagenesis and x-ray crystallography. An inactive mutant of BiSP (E232Q) was co-crystallized with sucrose. The structure revealed a substrate-binding mode comparable with that se...

  14. Failure to transmit avian vacuolar myelinopathy to mallard ducks

    Science.gov (United States)

    Larsen, R.S.; Nutter, F.B.; Augspurger, T.; Rocke, T.E.; Thomas, N.J.; Stoskopf, M.K.

    2003-01-01

    Avian vacuolar myelinopathy (AVM) is a neurologic disease that has been diagnosed in free-ranging birds in the southeastern United States. Bald eagles (Haliaeetus leuocephalus), American coots (Fulica americana), and mallards (Anas platyrhynchos) have been affected. Previous investigations have not determined the etiology of this disease. In November and December 2002, we attempted to induce AVM in game-farmed mallards through four, 7-day exposure trials. Mallards were housed in six groups of eight, with two of these groups serving as controls. One group was housed with AVM-affected coots; one group was tube fed daily with water from the lake where affected coots were captured; one group was tube fed daily with aquatic vegetation (Hydrilla verticillata) from the same lake; and another group was tube fed daily with sediment from the lake. No ducks exhibited clinical neurologic abnormalities consistent with AVM and no evidence of AVM was present at histopathologic examination of brain tissue. Although limitations in sample size, quantity of individual doses, frequency of dose administration, duration of exposure, and timing of these trials restrict the interpretation of the findings, AVM was not readily transmitted by direct contact, water, hydrilla, or sediment in this investigation.

  15. Regulation of vacuolar H+-ATPase in microglia by RANKL

    International Nuclear Information System (INIS)

    Serrano, Eric M.; Ricofort, Ryan D.; Zuo, Jian; Ochotny, Noelle; Manolson, Morris F.; Holliday, L. Shannon

    2009-01-01

    Vacuolar H + -ATPases (V-ATPases) are large electrogenic proton pumps composed of numerous subunits that play vital housekeeping roles in the acidification of compartments of the endocytic pathway. Additionally, V-ATPases play specialized roles in certain cell types, a capacity that is linked to cell type selective expression of isoforms of some of the subunits. We detected low levels of the a3 isoform of the a-subunit in mouse brain extracts. Examination of various brain-derived cell types by immunoblotting showed a3 was expressed in the N9 microglia cell line and in primary microglia, but not in other cell types. The expression of a3 in osteoclasts requires stimulation by Receptor Activator of Nuclear Factor κB-ligand (RANKL). We found that Receptor Activator of Nuclear Factor κB (RANK) was expressed by microglia. Stimulation of microglia with RANKL triggered increased expression of a3. V-ATPases in microglia were shown to bind microfilaments, and stimulation with RANKL increased the proportion of V-ATPase associated with the detergent-insoluble cytoskeletal fraction and with actin. In summary, microglia express the a3-subunit of V-ATPase. The expression of a3 and the interaction between V-ATPases and microfilaments was modulated by RANKL. These data suggest a novel molecular pathway for regulating microglia.

  16. Characterization of the vacuolar H sup + -ATPase of higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Manolson, M F

    1988-01-01

    The tonoplast H{sup +}-ATPase of Beta vulgaris L. was partially purified by Triton X-100 solubilization and Sepharose 4B chromatography resulting in the enrichment of two polypeptides. Kinetic analysis of ({alpha}-{sup 32}P) BzATP labeling identified the 57 kDa polypeptide as a nucleotide-binding subunit with a possible regulatory function. In addition, ({sup 14}C) DCCD-labeling identified a 16 kDa polypeptide as a putative transmembrane proton channel. It is concluded that the tonoplast H{sup +}-ATPase is a multimer composed of at least three polypeptides. Anti-57 and anti-67 kDa sera reacted with polypeptides of the corresponding size in bovine chromaffin granules, bovine clathrin-coated vesicles, and yeast vacuolar membranes, suggesting common structural features and common ancestry for endomembrane H{sup +}-ATPase of different organelles and different phyla. Anti-57 serum was used to isolate a cDNA encoding the corresponding subunit from Arabidopsis. Protein sequence analysis revealed homologies between endomembrane, F{sub 0}F{sub 1} and archaebacterial ATPases, suggesting that these different classes of ATPases have evolved from a common ancestor.

  17. TBK1 protects vacuolar integrity during intracellular bacterial infection.

    Directory of Open Access Journals (Sweden)

    Andrea L Radtke

    2007-03-01

    Full Text Available TANK-binding kinase-1 (TBK1 is an integral component of Type I interferon induction by microbial infection. The importance of TBK1 and Type I interferon in antiviral immunity is well established, but the function of TBK1 in bacterial infection is unclear. Upon infection of murine embryonic fibroblasts with Salmonella enterica serovar Typhimurium (Salmonella, more extensive bacterial proliferation was observed in tbk1(-/- than tbk1(+/+ cells. TBK1 kinase activity was required for restriction of bacterial infection, but interferon regulatory factor-3 or Type I interferon did not contribute to this TBK1-dependent function. In tbk1(-/-cells, Salmonella, enteropathogenic Escherichia coli, and Streptococcus pyogenes escaped from vacuoles into the cytosol where increased replication occurred, which suggests that TBK1 regulates the integrity of pathogen-containing vacuoles. Knockdown of tbk1 in macrophages and epithelial cells also resulted in increased bacterial localization in the cytosol, indicating that the role of TBK1 in maintaining vacuolar integrity is relevant in different cell types. Taken together, these data demonstrate a requirement for TBK1 in control of bacterial infection distinct from its established role in antiviral immunity.

  18. TBK1 Protects Vacuolar Integrity during Intracellular Bacterial Infection

    Science.gov (United States)

    Radtke, Andrea L; Delbridge, Laura M; Balachandran, Siddharth; Barber, Glen N; O'Riordan, Mary X. D

    2007-01-01

    TANK-binding kinase-1 (TBK1) is an integral component of Type I interferon induction by microbial infection. The importance of TBK1 and Type I interferon in antiviral immunity is well established, but the function of TBK1 in bacterial infection is unclear. Upon infection of murine embryonic fibroblasts with Salmonella enterica serovar Typhimurium (Salmonella), more extensive bacterial proliferation was observed in tbk1−/− than tbk1+/+ cells. TBK1 kinase activity was required for restriction of bacterial infection, but interferon regulatory factor-3 or Type I interferon did not contribute to this TBK1-dependent function. In tbk1−/−cells, Salmonella, enteropathogenic Escherichia coli, and Streptococcus pyogenes escaped from vacuoles into the cytosol where increased replication occurred, which suggests that TBK1 regulates the integrity of pathogen-containing vacuoles. Knockdown of tbk1 in macrophages and epithelial cells also resulted in increased bacterial localization in the cytosol, indicating that the role of TBK1 in maintaining vacuolar integrity is relevant in different cell types. Taken together, these data demonstrate a requirement for TBK1 in control of bacterial infection distinct from its established role in antiviral immunity. PMID:17335348

  19. Genome-wide analysis reveals the vacuolar pH-stat of Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Christopher L Brett

    Full Text Available Protons, the smallest and most ubiquitous of ions, are central to physiological processes. Transmembrane proton gradients drive ATP synthesis, metabolite transport, receptor recycling and vesicle trafficking, while compartmental pH controls enzyme function. Despite this fundamental importance, the mechanisms underlying pH homeostasis are not entirely accounted for in any organelle or organism. We undertook a genome-wide survey of vacuole pH (pH(v in 4,606 single-gene deletion mutants of Saccharomyces cerevisiae under control, acid and alkali stress conditions to reveal the vacuolar pH-stat. Median pH(v (5.27±0.13 was resistant to acid stress (5.28±0.14 but shifted significantly in response to alkali stress (5.83±0.13. Of 107 mutants that displayed aberrant pH(v under more than one external pH condition, functional categories of transporters, membrane biogenesis and trafficking machinery were significantly enriched. Phospholipid flippases, encoded by the family of P4-type ATPases, emerged as pH regulators, as did the yeast ortholog of Niemann Pick Type C protein, implicated in sterol trafficking. An independent genetic screen revealed that correction of pH(v dysregulation in a neo1(ts mutant restored viability whereas cholesterol accumulation in human NPC1(-/- fibroblasts diminished upon treatment with a proton ionophore. Furthermore, while it is established that lumenal pH affects trafficking, this study revealed a reciprocal link with many mutants defective in anterograde pathways being hyperacidic and retrograde pathway mutants with alkaline vacuoles. In these and other examples, pH perturbations emerge as a hitherto unrecognized phenotype that may contribute to the cellular basis of disease and offer potential therapeutic intervention through pH modulation.

  20. Effect of exogenous phytohormones and sucrose on ...

    African Journals Online (AJOL)

    The effect of exogenous phytohormones and sucrose on micropropagation and microtuberization from nodal cuttings of Manihot esculenta was studied. Direct and indirect organogeneses were established from these explants. When nodal cuttings were cultured in the presence of 0.01 to 0.1 mg.L-1 of BAP or NAA there was ...

  1. Advances in targeting the vacuolar proton-translocating ATPase (V-ATPase for anti-fungal therapy

    Directory of Open Access Journals (Sweden)

    Summer R. Hayek

    2014-01-01

    Full Text Available Vacuolar proton-translocating ATPase (V-ATPase is a membrane-bound, multi-subunit enzyme that uses the energy of ATP hydrolysis to pump protons across membranes. V-ATPase activity is critical for pH homeostasis and organelle acidification as well as for generation of the membrane potential that drives secondary transporters and cellular metabolism. V-ATPase is highly conserved across species and is best characterized in the model fungus Saccharomyces cerevisiae (S. cerevisiae. However, recent studies in mammals have identified significant alterations from fungi, particularly in the isoform composition of the 14 subunits and in the regulation of complex disassembly. These differences could be exploited for selectivity between fungi and humans and highlight the potential for V-ATPase as an anti-fungal drug target. Candida albicans (C. albicans is a major human fungal pathogen and causes fatality in 35% of systemic infections, even with anti-fungal treatment. The pathogenicity of C. albicans correlates with environmental, vacuolar, and cytoplasmic pH regulation, and V-ATPase appears to play a fundamental role in each of these processes. Genetic loss of V-ATPase in pathogenic fungi leads to defective virulence, and a comprehensive picture of the mechanisms involved is emerging. Recent studies have explored the practical utility of V-ATPase as an anti-fungal drug target in C. albicans, including pharmacological inhibition, azole therapy, and targeting of downstream pathways. This overview will discuss these studies as well as hypothetical ways to target V-ATPase and novel high-throughput methods for use in future drug discovery screens.

  2. TRANSPARENT TESTA 13 is a tonoplast P3A -ATPase required for vacuolar deposition of proanthocyanidins in Arabidopsis thaliana seeds

    NARCIS (Netherlands)

    Appelhagen, I.; Nordholt, N.; Seidel, T.; Spelt, K.; Koes, R.; Quattrochio, F.; Sagasser, M.; Weisshaar, B.

    2015-01-01

    Intracellular pH homeostasis is essential for all living cells. In plants, pH is usually maintained by three structurally distinct and differentially localized types of proton pump: P-type H(+) -ATPases in the plasma membrane, and multimeric vacuolar-type H(+) -ATPases (V-ATPases) and vacuolar H(+)

  3. Arabidopsis Vacuolar Pyrophosphatase gene (AVP1) induces drought and salt tolerance in Nicotiana tabacum plants (abstract)

    International Nuclear Information System (INIS)

    Arif, A.; Mohsin, A.M.; Shafiq, S.; Zafar, Y.; Hameed, S.M.; Arif, M.; Javed, M.; Gaxiola, R.A.

    2005-01-01

    Drought and salinity are global problems. In Pakistan these problems are increasing to an alarming situation due to low rain-fall and bad agricultural practices. Salt and drought stress shows a high degree of similarity with respect to physiological, biochemical, molecular and genetic effects. This is due to the fact that sub-lethal salt-stress condition is ultimately an osmotic effect which is apparently similar to that brought in by water deficit. Genetic engineering allows the re-introduction of plant genes into their genomes by increasing their expression level. Plant vacuoles play a central role in cellular mechanisms of adaptation to salinity and drought stresses. In principle, increased vacuolar solute accumulation should have a positive impact in the adaptation of plants to salinity and drought. The active transport of the solutes depends on the proton gradients established by proton pumps. We have over expressed Arabidopsis gene AVP1 (Arabidopsis thaliana vacuolar pyro phosphatase H/sup +/ pump) to increase drought/salt tolerance in tobacco. The AVP1 ORF with a tandem repeat of 358 promoter was cloned in pPZP212 vector and Agrobacterium-mediated transformation was performed. Transgenic plants were selected on plant nutrient agar medium supplemented with 50 mg/liter kanamycin. Transgenic plants were confirmed for transfer of genes by AVP1 and nptll gene specific PCR and Southern hybridization. AVP1 transgenic plants were screened for salt tolerance by providing NaCl solution in addition to nutrient solution. AVP1 transgenic plants showed tolerance up to 300 mM NaCl as compared to control which died ten days after 200 mM NaCl. Sodium and potassium were measured in salt treated and control plants. Results showed that sodium ion uptake in the salt treated transgenic plants was four times more as compared to wild type. This remarkable increase in Na/sup +/ ion uptake indicates that AVP1 vacuole proton pumps are actively involved in the transport of Na

  4. Regulation of proximal tubule vacuolar H+-ATPase by PKA and AMP-activated protein kinase

    Science.gov (United States)

    Al-bataineh, Mohammad M.; Gong, Fan; Marciszyn, Allison L.; Myerburg, Michael M.

    2014-01-01

    The vacuolar H+-ATPase (V-ATPase) mediates ATP-driven H+ transport across membranes. This pump is present at the apical membrane of kidney proximal tubule cells and intercalated cells. Defects in the V-ATPase and in proximal tubule function can cause renal tubular acidosis. We examined the role of protein kinase A (PKA) and AMP-activated protein kinase (AMPK) in the regulation of the V-ATPase in the proximal tubule as these two kinases coregulate the V-ATPase in the collecting duct. As the proximal tubule V-ATPases have different subunit compositions from other nephron segments, we postulated that V-ATPase regulation in the proximal tubule could differ from other kidney tubule segments. Immunofluorescence labeling of rat ex vivo kidney slices revealed that the V-ATPase was present in the proximal tubule both at the apical pole, colocalizing with the brush-border marker wheat germ agglutinin, and in the cytosol when slices were incubated in buffer alone. When slices were incubated with a cAMP analog and a phosphodiesterase inhibitor, the V-ATPase accumulated at the apical pole of S3 segment cells. These PKA activators also increased V-ATPase apical membrane expression as well as the rate of V-ATPase-dependent extracellular acidification in S3 cell monolayers relative to untreated cells. However, the AMPK activator AICAR decreased PKA-induced V-ATPase apical accumulation in proximal tubules of kidney slices and decreased V-ATPase activity in S3 cell monolayers. Our results suggest that in proximal tubule the V-ATPase subcellular localization and activity are acutely coregulated via PKA downstream of hormonal signals and via AMPK downstream of metabolic stress. PMID:24553431

  5. Covalent structures of potato tuber lipases (patatins) and implications for vacuolar import

    DEFF Research Database (Denmark)

    Welinder, Karen Gjesing; Jørgensen, Malene

    that the path is via the Golgi apparatus. However, the vacuolar targeting signal has never been identified for this storage and defence protein, which amounts to 25-40% of tuber protein. We propose that a six-residue ct-propeptide, -ANKASY-COO- composes this signal. The crystallographic structure...... the Danish Research Council for Technology and Production, and grant 2052-03-0022 from the Danish Research Agency.   Reference Welinder KG, Jørgensen M (2009) Covalent structures of potato tuber lipases (patatins) and implications for vacuolar import. J. Biol. Chem., Feb 2009; doi:10.1074/jbc.M809674200....

  6. Regulation of transport processes across the tonoplast membrane

    Directory of Open Access Journals (Sweden)

    Oliver eTrentmann

    2014-09-01

    Full Text Available In plants, the vacuole builds up the cellular turgor and represents an important component in cellular responses to diverse stress stimuli. Rapid volume changes of cells, particularly of motor cells, like guard cells, are caused by variation of osmolytes and consequently of the water contents in the vacuole. Moreover, directed solute uptake into or release out of the large central vacuole allows adaptation of cytosolic metabolite levels according to the current physiological requirements and specific cellular demands. Therefore, solute passage across the vacuolar membrane, the tonoplast, has to be tightly regulated. Important principles in vacuolar transport regulation are changes of tonoplast transport protein abundances by differential expression of genes or changes of their activities, e.g. due to post-translational modification or by interacting proteins. Because vacuolar transport is in most cases driven by an electro-chemical gradient altered activities of tonoplast proton pumps significantly influence vacuolar transport capacities. Intense studies on individual tonoplast proteins but also unbiased system biological approaches have provided important insights into the regulation of vacuolar transport. This short review refers to selected examples of tonoplast proteins and their regulation, with special focus on protein phosphorylation.

  7. Determining sucrose recovery in Saccarrum officinarum L. using ...

    African Journals Online (AJOL)

    Variation for sucrose content on single factor basis was caused by tillers, therefore, this character was the most important to increase overall sucrose of S. officinarum L. However, second variable model exhibited that tillers and internodal length were important traits for increasing overall sucrose in sugarcane.

  8. Comparative Transcriptome Analysis Reveals Critical Function of Sucrose Metabolism Related-Enzymes in Starch Accumulation in the Storage Root of Sweet Potato

    Directory of Open Access Journals (Sweden)

    Kai Zhang

    2017-06-01

    Full Text Available The starch properties of the storage root (SR affect the quality of sweet potato (Ipomoea batatas (L. Lam.. Although numerous studies have analyzed the accumulation and properties of starch in sweet potato SRs, the transcriptomic variation associated with starch properties in SR has not been quantified. In this study, we measured the starch and sugar contents and analyzed the transcriptome profiles of SRs harvested from sweet potatoes with high, medium, and extremely low starch contents, at five developmental stages [65, 80, 95, 110, and 125 days after transplanting (DAP]. We found that differences in both water content and starch accumulation in the dry matter affect the starch content of SRs in different sweet potato genotypes. Based on transcriptome sequencing data, we assembled 112336 unigenes, and identified several differentially expressed genes (DEGs involved in starch and sucrose metabolism, and revealed the transcriptional regulatory network controlling starch and sucrose metabolism in sweet potato SRs. Correlation analysis between expression patterns and starch and sugar contents suggested that the sugar–starch conversion steps catalyzed by sucrose synthase (SuSy and UDP-glucose pyrophosphorylase (UGPase may be essential for starch accumulation in the dry matter of SRs, and IbβFRUCT2, a vacuolar acid invertase, might also be a key regulator of starch content in the SRs. Our results provide valuable resources for future investigations aimed at deciphering the molecular mechanisms determining the starch properties of sweet potato SRs.

  9. Covalent structures of potato tuber lipases (patatins) and implications for vacuolar import

    DEFF Research Database (Denmark)

    Welinder, Karen Gjesing; Jørgensen, Malene

    2009-01-01

    patatin (Rydel, T. J., Williams, J. M., Krieger, E., Moshiri, F., Stallings, W. C., Brown, S. M., Pershing, J. C., Prucell, J. P., and Alibhai, M. F. (2003) Biochemistry 42, 6696-6708), which included this propeptide thus, for the first time, shows the structure of a putative ligand of the vacuolar...

  10. Analysis of sucrose-induced small RNAs in Streptococcus mutans in the presence of different sucrose concentrations.

    Science.gov (United States)

    Liu, Shan Shan; Zhu, Wen Hui; Zhi, Qing Hui; Liu, Jia; Wang, Yan; Lin, Huan Cai

    2017-07-01

    Streptococcus mutans (S. mutans) is the major pathogen contributing to dental caries. Sucrose is an important carbohydrate source for S. mutans and is crucial for dental caries. Small RNAs (sRNAs) are key post-transcriptional regulators of stress adaptation and virulence in bacteria. Here, for the first time, we created three replicate RNA libraries exposed to either 1 or 5% sucrose. The expression levels of sRNAs and target genes (gtfB, gtfC, and spaP) related to virulence were assessed. In addition, some phenotypic traits were evaluated. We obtained 2125 sRNA candidates with at least 100 average reads in 1% sucrose or 5% sucrose. Of these candidates, 2 were upregulated and 20 were downregulated in 1% sucrose. Six of these 22 differentially expressed sRNAs were validated by qRT-PCR. The expression level of target gene gtfB was higher in 1% sucrose. The adherence ratio of S. mutans was higher in 1% sucrose than in 5% sucrose. The synthesis of water-insoluble glucans (WIGs) was significantly higher in 5% sucrose than in 1% sucrose. These data suggest that a series of sRNAs can be induced in response to sucrose, and that some sRNAs might be involved in the regulation of phenotypes, providing new insight into the prevention of caries.

  11. Tonoplast Na+/H+ Antiport Activity and Its Energization by the Vacuolar H+-ATPase in the Halophytic Plant Mesembryanthemum crystallinum L.

    Science.gov (United States)

    Barkla, B. J.; Zingarelli, L.; Blumwald, E.; Smith, JAC.

    1995-10-01

    Tonoplast vesicles were isolated from leaf mesophyll tissue of the inducible Crassulacean acid metabolism plant Mesembryanthemum crystallinum to investigate the mechanism of vacuolar Na+ accumulation in this halophilic species. In 8-week-old plants exposed to 200 mM NaCl for 2 weeks, tonoplast H+-ATPase activity was approximately doubled compared with control plants of the same age, as determined by rates of both ATP hydrolysis and ATP-dependent H+ transport. Evidence was also obtained for the presence of an electroneutral Na+/H+ antiporter at the tonoplast that is constitutively expressed, since extravesicular Na+ was able to dissipate a pre-existing transmembrane pH gradient. Initial rates of H+ efflux showed saturation kinetics with respect to extravesicular Na+ concentration and were 2.1-fold higher from vesicles of salt-treated plants compared with the controls. Na+-dependent H+ efflux also showed a high selectivity for Na+ over K+, was insensitive to the transmembrane electrical potential difference, and was more than 50% inhibited by 200 [mu]M N-amidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride. The close correlation between increased Na+/H+ antiport and H+-ATPase activities in response to salt treatment suggests that accumulation of the very high concentrations of vacuolar Na+ found in M. crystallinum is energized by the H+ electrochemical gradient across the tonoplast.

  12. Enhanced Sucrose Loading Improves Rice Yield by Increasing Grain Size.

    Science.gov (United States)

    Wang, Liang; Lu, Qingtao; Wen, Xiaogang; Lu, Congming

    2015-12-01

    Yield in cereals is a function of grain number and size. Sucrose (Suc), the main carbohydrate product of photosynthesis in higher plants, is transported long distances from source leaves to sink organs such as seeds and roots. Here, we report that transgenic rice plants (Oryza sativa) expressing the Arabidopsis (Arabidopsis thaliana) phloem-specific Suc transporter (AtSUC2), which loads Suc into the phloem under control of the phloem protein2 promoter (pPP2), showed an increase in grain yield of up to 16% relative to wild-type plants in field trials. Compared with wild-type plants, pPP2::AtSUC2 plants had larger spikelet hulls and larger and heavier grains. Grain filling was accelerated in the transgenic plants, and more photoassimilate was transported from the leaves to the grain. In addition, microarray analyses revealed that carbohydrate, amino acid, and lipid metabolism was enhanced in the leaves and grain of pPP2::AtSUC2 plants. Thus, enhancing Suc loading represents a promising strategy to improve rice yield to feed the global population. © 2015 American Society of Plant Biologists. All Rights Reserved.

  13. Sucrose and warmth for analgesia in healthy newborns: an RCT.

    Science.gov (United States)

    Gray, Larry; Garza, Elizabeth; Zageris, Danielle; Heilman, Keri J; Porges, Stephen W

    2015-03-01

    Increasing data suggest that neonatal pain has long-term consequences. Nonpharmacologic techniques (sucrose taste, pacifier suckling, breastfeeding) are effective and now widely used to combat minor neonatal pain. This study examined the analgesic effect of sucrose combined with radiant warmth compared with the taste of sucrose alone during a painful procedure in healthy full-term newborns. A randomized, controlled trial included 29 healthy, full-term newborns born at the University of Chicago Hospital. Both groups of infants were given 1.0 mL of 25% sucrose solution 2 minutes before the vaccination, and 1 group additionally was given radiant warmth from an infant warmer before the vaccination. We assessed pain by comparing differences in cry, grimace, heart rate variability (ie, respiratory sinus arrhythmia), and heart rate between the groups. The sucrose plus warmer group cried and grimaced for 50% less time after the vaccination than the sucrose alone group (P < .05, respectively). The sucrose plus warmer group had lower heart rate and heart rate variability (ie, respiratory sinus arrhythmia) responses compared with the sucrose alone group (P < .01), reflecting a greater ability to physiologically regulate in response to the painful vaccination. The combination of sucrose and radiant warmth is an effective analgesic in newborns and reduces pain better than sucrose alone. The ready availability of this practical nonpharmacologic technique has the potential to reduce the burden of newborn pain. Copyright © 2015 by the American Academy of Pediatrics.

  14. Sucrose accumulation in watermelon fruits: genetic variation and biochemical analysis.

    Science.gov (United States)

    Yativ, Merav; Harary, Idan; Wolf, Shmuel

    2010-05-15

    Sugar accumulation, the key process determining fruit quality, is controlled by both the translocation of sugars and their metabolism in developing fruits. Sugar composition in watermelon, as in all cucurbit fruits, includes sucrose, fructose and glucose. The proportions of these three sugars are determined primarily by three enzyme families: invertases, sucrose synthases (SuSys) and sucrose phosphate synthases (SPSs). The goal of the present research was to explore the process of sugar metabolism in watermelon fruits. Crosses between the domestic watermelon (Citrullus lanatus) and three wild species provided a wide germplasm to explore genetic variability in sugar composition and metabolism. This survey demonstrated great genetic variability in sugar content and in the proportions of sucrose, glucose and fructose in mature fruits. Genotypes accumulating high and low percentage of sucrose provided an experimental system to study sugar metabolism in developing fruits. Insoluble invertase activity was high and constant throughout fruit development in control lines and in genotypes accumulating low levels of sucrose, while in genotypes accumulating high levels of sucrose, activity declined sharply 4 weeks after pollination. Soluble acid invertase activity was significantly lower in genotypes accumulating high levels of sucrose than in low-sucrose-accumulating genotypes. Conversely, activities of SuSy and SPS were higher in the high-sucrose-accumulating genotypes. The present results establish that, within the genus Citrullus, there are genotypes that accumulate a high percentage of sucrose in the fruit, while others accumulate high percentages of glucose and fructose. The significant negative correlation between insoluble invertase activity and fruit sucrose level suggests that sucrose accumulation is affected by both phloem unloading and sugar metabolism. (c) 2009 Elsevier GmbH. All rights reserved.

  15. Leaves Of Cut Rose Flower Convert Exogenously Applied Glucose To Sucrose And Translocate It To Petals

    Directory of Open Access Journals (Sweden)

    Horibe Takanori

    2014-12-01

    Full Text Available To understand the role that the leaves play in the translocation of soluble carbohydrates in cut rose flowers, we first evaluated the effect of leaf removal on flower quality and the sugar content in petals. Cut rose flowers with leaves had higher soluble sugar content in petals compared with cut flower without leaves. Next, we treated cut flowers with radioactive glucose to clarify translocation routes of exogenously applied sugar. There was no significant difference between the specific radioactivity of sucrose and glucose in leaves, but specific radioactivity of sucrose in petals was much higher than that of glucose. These results suggested that most of the exogenously applied glucose first moved to the leaves, where it was converted into sucrose and then the synthesised sucrose was translocated to the petals. Our results showed that the leaves of cut rose flowers play an important role in the metabolism and transportation of exogenously applied soluble carbohydrates toward the petals, thus contributing to sustaining the post-harvest quality.

  16. Analysis and protease-catalysed synthesis of sucrose alkanoate regioisomers

    DEFF Research Database (Denmark)

    Lie, Aleksander

    2014-01-01

    The aims of the presented research were to develop quantifiable methods for reversed-phase high-performance liquid chromatography analysis of sucrose alkanoate regioisomers and to investigate the activity and regioisomeric distribution in the biocatalytic esterification of sucrose with vinyl laur...... in the reaction mixture appeared to be catalysed by the presence of aluminosilicate molecular sieves in the reaction medium. Mass spectrometry analysis of sucrose laurate product confirmed the molecular mass.......The aims of the presented research were to develop quantifiable methods for reversed-phase high-performance liquid chromatography analysis of sucrose alkanoate regioisomers and to investigate the activity and regioisomeric distribution in the biocatalytic esterification of sucrose with vinyl...... laurate in DMF using serine proteases and a metalloprotease. A broad range of elution strategies for the chromatographic analysis of sucrose alkanoate regioisomers was systematically investigated using design of experiments strategies and statistical and multivariate analysis and modelling. Efficiency...

  17. Rapid Nuclear Exclusion of Hcm1 in Aging Saccharomyces cerevisiae Leads to Vacuolar Alkalization and Replicative Senescence

    Directory of Open Access Journals (Sweden)

    Ata Ghavidel

    2018-05-01

    Full Text Available The yeast, Saccharomyces cerevisiae, like other higher eukaryotes, undergo a finite number of cell divisions before exiting the cell cycle due to the effects of aging. Here, we show that yeast aging begins with the nuclear exclusion of Hcm1 in young cells, resulting in loss of acidic vacuoles. Autophagy is required for healthy aging in yeast, with proteins targeted for turnover by autophagy directed to the vacuole. Consistent with this, vacuolar acidity is necessary for vacuolar function and yeast longevity. Using yeast genetics and immunofluorescence microscopy, we confirm that vacuolar acidity plays a critical role in cell health and lifespan, and is potentially maintained by a series of Forkhead Box (Fox transcription factors. An interconnected transcriptional network involving the Fox proteins (Fkh1, Fkh2 and Hcm1 are required for transcription of v-ATPase subunits and vacuolar acidity. As cells age, Hcm1 is rapidly excluded from the nucleus in young cells, blocking the expression of Hcm1 targets (Fkh1 and Fkh2, leading to loss of v-ATPase gene expression, reduced vacuolar acidification, increased α-syn-GFP vacuolar accumulation, and finally, diminished replicative lifespan (RLS. Loss of vacuolar acidity occurs about the same time as Hcm1 nuclear exclusion and is conserved; we have recently demonstrated that lysosomal alkalization similarly contributes to aging in C. elegans following a transition from progeny producing to post-reproductive life. Our data points to a molecular mechanism regulating vacuolar acidity that signals the end of RLS when acidification is lost.

  18. Evolutionary divergence of plant borate exporters and critical amino acid residues for the polar localization and boron-dependent vacuolar sorting of AtBOR1

    KAUST Repository

    Wakuta, Shinji

    2015-01-24

    Boron (B) is an essential micronutrient for plants but is toxic when accumulated in excess. The plant BOR family encodes plasma membrane-localized borate exporters (BORs) that control translocation and homeostasis of B under a wide range of conditions. In this study, we examined the evolutionary divergence of BORs among terrestrial plants and showed that the lycophyte Selaginella moellendorffii and angiosperms have evolved two types of BOR (clades I and II). Clade I includes AtBOR1 and homologs previously shown to be involved in efficient transport of B under conditions of limited B availability. AtBOR1 shows polar localization in the plasma membrane and high-B-induced vacuolar sorting, important features for efficient B transport under low-B conditions, and rapid down-regulation to avoid B toxicity. Clade II includes AtBOR4 and barley Bot1 involved in B exclusion for high-B tolerance. We showed, using yeast complementation and B transport assays, that three genes in S. moellendorffii, SmBOR1 in clade I and SmBOR3 and SmBOR4 in clade II, encode functional BORs. Furthermore, amino acid sequence alignments identified an acidic di-leucine motif unique in clade I BORs. Mutational analysis of AtBOR1 revealed that the acidic di-leucine motif is required for the polarity and high-B-induced vacuolar sorting of AtBOR1. Our data clearly indicated that the common ancestor of vascular plants had already acquired two types of BOR for low- and high-B tolerance, and that the BOR family evolved to establish B tolerance in each lineage by adapting to their environments. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  19. A vacuolar carboxypeptidase mutant of Arabidopsis thaliana is degraded by the ERAD pathway independently of its N-glycan

    International Nuclear Information System (INIS)

    Yamamoto, Masaya; Kawanabe, Mitsuyoshi; Hayashi, Yoko; Endo, Toshiya; Nishikawa, Shuh-ichi

    2010-01-01

    Misfolded proteins produced in the endoplasmic reticulum (ER) are degraded by a mechanism, the ER-associated degradation (ERAD). Here we report establishment of the experimental system to analyze the ERAD in plant cells. Carboxypeptidase Y (CPY) is a vacuolar enzyme and its mutant CPY* is degraded by the ERAD in yeast. Since Arabidopsis thaliana has AtCPY, an ortholog of yeast CPY, we constructed and expressed fusion proteins consisting of AtCPY and GFP and of AtCPY*, which carries a mutation homologous to yeast CPY*, and GFP in A. thaliana cells. While AtCPY-GFP was efficiently transported to the vacuole, AtCPY*-GFP was retained in the ER to be degraded in proteasome- and Cdc48-dependent manners. We also found that AtCPY*-GFP was degraded by the ERAD in yeast cells, but that its single N-glycan did not function as a degradation signal in yeast or plant cells. Therefore, AtCPY*-GFP can be used as a marker protein to analyze the ERAD pathway, likely for nonglycosylated substrates, in plant cells.

  20. A vacuolar carboxypeptidase mutant of Arabidopsis thaliana is degraded by the ERAD pathway independently of its N-glycan

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Masaya; Kawanabe, Mitsuyoshi; Hayashi, Yoko; Endo, Toshiya [Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Nishikawa, Shuh-ichi, E-mail: shuh@biochem.chem.nagoya-u.ac.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)

    2010-03-12

    Misfolded proteins produced in the endoplasmic reticulum (ER) are degraded by a mechanism, the ER-associated degradation (ERAD). Here we report establishment of the experimental system to analyze the ERAD in plant cells. Carboxypeptidase Y (CPY) is a vacuolar enzyme and its mutant CPY* is degraded by the ERAD in yeast. Since Arabidopsis thaliana has AtCPY, an ortholog of yeast CPY, we constructed and expressed fusion proteins consisting of AtCPY and GFP and of AtCPY*, which carries a mutation homologous to yeast CPY*, and GFP in A. thaliana cells. While AtCPY-GFP was efficiently transported to the vacuole, AtCPY*-GFP was retained in the ER to be degraded in proteasome- and Cdc48-dependent manners. We also found that AtCPY*-GFP was degraded by the ERAD in yeast cells, but that its single N-glycan did not function as a degradation signal in yeast or plant cells. Therefore, AtCPY*-GFP can be used as a marker protein to analyze the ERAD pathway, likely for nonglycosylated substrates, in plant cells.

  1. Functional characterization of sucrose phosphorylase and scrR, a regulator of sucrose metabolism in Lactobacillus reuteri.

    Science.gov (United States)

    Teixeira, Januana S; Abdi, Reihaneh; Su, Marcia Shu-Wei; Schwab, Clarissa; Gänzle, Michael G

    2013-12-01

    Lactobacillus reuteri harbours alternative enzymes for sucrose metabolism, sucrose phosphorylase, fructansucrases, and glucansucrases. Sucrose phosphorylase and fructansucrases additionally contribute to raffinose metabolism. Glucansucrases and fructansucrases produce exopolysaccharides as alternative to sucrose hydrolysis. L. reuteri LTH5448 expresses a levansucrase (ftfA) and sucrose phosphorylase (scrP), both are inducible by sucrose. This study determined the contribution of scrP to sucrose and raffinose metabolism in L. reuteri LTH5448, and elucidated the role of scrR in regulation sucrose metabolism. Disruption of scrP and scrR was achieved by double crossover mutagenesis. L. reuteri LTH5448, LTH5448ΔscrP and LTH5448ΔscrR were characterized with respect to growth and metabolite formation with glucose, sucrose, or raffinose as sole carbon source. Inactivation of scrR led to constitutive transcription of scrP and ftfA, demonstrating that scrR is negative regulator. L. reuteri LTH5448 and the LTH5448ΔscrP or LTH5448ΔscrR mutant strains did not differ with respect to glucose, sucrose or raffinose utilization. However, L. reuteri LTH5448ΔscrP produced more levan, indicating that the lack of sucrose phosphorylase is compensated by an increased metabolic flux through levansucrase. In conclusion, the presence of alternate pathways for sucrose and raffinose metabolism and their regulation indicate that these substrates, which are abundant in plants, are preferred carbohydrate sources for L. reuteri. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Appropriate vacuolar acidification in Saccharomyces cerevisiae is associated with efficient high sugar fermentation.

    Science.gov (United States)

    Nguyen, Trung D; Walker, Michelle E; Gardner, Jennifer M; Jiranek, Vladimir

    2018-04-01

    Vacuolar acidification serves as a homeostatic mechanism to regulate intracellular pH, ion and chemical balance, as well as trafficking and recycling of proteins and nutrients, critical for normal cellular function. This study reports on the importance of vacuole acidification during wine-like fermentation. Ninety-three mutants (homozygous deletions in lab yeast strain, BY4743), which result in protracted fermentation when grown in a chemically defined grape juice with 200 g L -1 sugar (pH 3.5), were examined to determine whether fermentation protraction was in part due to a dysfunction in vacuolar acidification (VA) during the early stages of fermentation, and whether VA was responsive to the initial sugar concentration in the medium. Cells after 24 h growth were dual-labelled with propidium iodide and vacuolar specific probe 6-carboxyfluorescein diacetate (6-CFDA) and examined with a FACS analyser for viability and impaired VA, respectively. Twenty mutants showed a greater than two-fold increase in fluorescence intensity; the experimental indicator for vacuolar dysfunction; 10 of which have not been previously annotated to this process. With the exception of Δhog1, Δpbs2 and Δvph1 mutants, where dysfunction was directly related to osmolality; the remainder exhibited increased CF-fluorescence, independent of sugar concentration at 20 g L -1 or 200 g L -1 . These findings offer insight to the importance of VA to cell growth in high sugar media. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Hereditary vacuolar internal anal sphincter myopathy causing proctalgia fugax and constipation: a new case contribution.

    Science.gov (United States)

    de la Portilla, Fernando; Borrero, Juan José; Rafel, Enrique

    2005-03-01

    Hereditary anal sphincter myopathy is rare. We present a family with one affected member with proctalgia fugax, constipation and internal anal sphincter hypertrophy. Ultrastructural findings show vacuolization of smooth muscle cells without the characteristic polyglucosan inclusion. Further relief of symptoms was obtained using an oral calcium antagonist. Based on clinical presentation, endosonography and morphological findings, we consider our case is a histological variant of the vacuolar myopathy originally described.

  4. Compartmentation of sucrose during radial transfer in mature sorghum culm

    Directory of Open Access Journals (Sweden)

    Vietor Donald M

    2007-06-01

    Full Text Available Abstract Background The sucrose that accumulates in the culm of sorghum (Sorghum bicolor (L. Moench and other large tropical andropogonoid grasses can be of commercial value, and can buffer assimilate supply during development. Previous study conducted with intact plants showed that sucrose can be radially transferred to the intracellular compartment of mature ripening sorghum internode without being hydrolysed. In this study, culm-infused radiolabelled sucrose was traced between cellular compartments and among related metabolites to determine if the compartmental path of sucrose during radial transfer in culm tissue was symplasmic or included an apoplasmic step. This transfer path was evaluated for elongating and ripening culm tissue of intact plants of two semidwarf grain sorghums. The metabolic path in elongating internode tissue was also evaluated. Results On the day after culm infusion of the tracer sucrose, the specific radioactivity of sucrose recovered from the intracellular compartment of growing axillary-branch tissue was greater (nearly twice than that in the free space, indicating that sucrose was preferentially transferred through symplasmic routes. In contrast, the sucrose specific radioactivity in the intracellular compartment of the mature (ripening culm tissue was probably less (about 3/4's than that in free space indicating that sucrose was preferentially transferred through routes that included an apoplasmic step. In growing internodes of the axillary branch of sorghum, the tritium label initially provided in the fructose moiety of sucrose molecules was largely (81% recovered in the fructose moiety, indicating that a large portion of sucrose molecules is not hydrolysed and resynthesized during radial transfer. Conclusion During radial transfer of sucrose in ripening internodes of intact sorghum plants, much of the sucrose is transferred intact (without hydrolysis and resynthesis and primarily through a path that includes an

  5. Kinetically Determined Hygroscopicity and Efflorescence of Sucrose-Ammonium Sulfate Aerosol Droplets under Lower Relative Humidity.

    Science.gov (United States)

    Wang, Lin-Na; Cai, Chen; Zhang, Yun-Hong

    2017-09-14

    Organic aerosols will likely form in semisolid, glassy, and high viscous state in the atmosphere, which show nonequilibrium kinetic characteristics at low relative humidity (RH) conditions. In this study, we applied optical tweezers to investigate the water transport in a sucrose/(NH 4 ) 2 SO 4 droplet with high organic to inorganic mole ratio (OIR). The characteristic time ratio between the droplet radius and the RH was used to describe the water mass transfer difference dependent on RH. For OIR greater than 1:1 in sucrose/(NH 4 ) 2 SO 4 droplets, the characteristic time ratio at low RH (∼60%). We also coupled vacuum FTIR spectrometer and a high-speed photography to study the efflorescence process in sucrose/(NH 4 ) 2 SO 4 droplets with low OIR. The crystalline fraction of (NH 4 ) 2 SO 4 was used to understand efflorescence behavior when the RH was linearly decreasing with a velocity of 1.2% RH min -1 . Because of suppression of (NH 4 ) 2 SO 4 nucleation by addition of sucrose, the efflorescence relative humidity (ERH) of (NH 4 ) 2 SO 4 decrease from the range of ∼48.2% to ∼36.1% for pure (NH 4 ) 2 SO 4 droplets to from ∼44.7% to ∼25.4%, from ∼43.2% to ∼21.2%, and from ∼41.7% to ∼21.1% for the mixed droplets with OIR of 1:4, 1:3, and 1:2, respectively. No crystallization was observed when the OIR is higher than 1:1. Suppression of (NH 4 ) 2 SO 4 crystal growth was also observed under high viscous sucrose/(NH 4 ) 2 SO 4 droplets at lower RH.

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

    Science.gov (United States)

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

    2000-01-01

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

  7. Subcellular localization and vacuolar targeting of sorbitol dehydrogenase in apple seed.

    Science.gov (United States)

    Wang, Xiu-Ling; Hu, Zi-Ying; You, Chun-Xiang; Kong, Xiu-Zhen; Shi, Xiao-Pu

    2013-09-01

    Sorbitol is the primary photosynthate and translocated carbohydrate in fruit trees of the Rosaceae family. NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), which mainly catalyzes the oxidation of sorbitol to fructose, plays a key role in regulating sink strength in apple. In this study, we found that apple NAD-SDH was ubiquitously distributed in epidermis, parenchyma, and vascular bundle in developing cotyledon. NAD-SDH was localized in the cytosol, the membranes of endoplasmic reticulum and vesicles, and the vacuolar lumen in the cotyledon at the middle stage of seed development. In contrast, NAD-SDH was mainly distributed in the protein storage vacuoles in cotyledon at the late stage of seed development. Sequence analysis revealed there is a putative signal peptide (SP), also being predicated to be a transmembrane domain, in the middle of proteins of apple NAD-SDH isoforms. To investigate whether the putative internal SP functions in the vacuolar targeting of NAD-SDH, we analyzed the localization of the SP-deletion mutants of MdSDH5 and MdSDH6 (two NAD-SDH isoforms in apple) by the transient expression system in Arabidopsis protoplasts. MdSDH5 and MdSDH6 were not localized in the vacuoles after their SPs were deleted, suggesting the internal SP functions in the vacuolar targeting of apple NAD-SDH. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu

    2014-11-21

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  9. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu; Gehring, Christoph A; Zhu, Jianhua; Li, Feng-Min; Zhu, Jian-Kang; Xiong, Liming

    2014-01-01

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  10. Sequence analysis of cereal sucrose synthase genes and isolation ...

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    Oct 18, 2007 ... sequencing of sucrose synthase gene fragment from sor- ghum using primers designed at their conserved exons. MATERIALS AND METHODS. Multiple sequence alignment. Sucrose synthase gene sequences of various cereals like rice, maize, and barley were accessed from NCBI Genbank database.

  11. Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers

    Science.gov (United States)

    Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y.; Miao, Xiaoqing

    2013-01-01

    In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources. PMID:24194958

  12. Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers.

    Science.gov (United States)

    Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y; Miao, Xiaoqing

    2013-01-01

    In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

  13. Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers.

    Directory of Open Access Journals (Sweden)

    Wenchao Yang

    Full Text Available In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

  14. Functionality of Inulin as a Sucrose Replacer in Cookie Baking

    Science.gov (United States)

    Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

  15. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    HP

    Purpose: To investigate the effect of sucrose esters on the physicochemical properties of wheat starch. Methods: Sucrose ester was mixed with wheat starch extracted from normal soft wheat cultivars and heated. Change in starch properties arising from the interaction between were assessed for starch blue value, viscosity ...

  16. Sucrose and Saccharomyces cerevisiae: a relationship most sweet.

    Science.gov (United States)

    Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk, Boris Ugarte; Gombert, Andreas Karoly

    2016-02-01

    Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is focused on sucrose metabolism in S. cerevisiae, a rather unexplored subject in the scientific literature. An analysis of sucrose availability in nature and yeast sugar metabolism was performed, in order to understand the molecular background that makes S. cerevisiae consume this sugar efficiently. A historical overview on the use of sucrose and S. cerevisiae by humans is also presented considering sugarcane and sugarbeet as the main sources of this carbohydrate. Physiological aspects of sucrose consumption are compared with those concerning other economically relevant sugars. Also, metabolic engineering efforts to alter sucrose catabolism are presented in a chronological manner. In spite of its extensive use in yeast-based industries, a lot of basic and applied research on sucrose metabolism is imperative, mainly in fields such as genetics, physiology and metabolic engineering. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Citrate increases glass transition temperature of vitrified sucrose preparations

    NARCIS (Netherlands)

    Kets, E.P.W.; Lipelaar, P.J.; Hoekstra, F.A.; Vromans, H.

    2004-01-01

    The aim of this study was to investigate the effect of sodium citrate on the properties of dried amorphous sucrose glasses. Addition of sodium citrate to a sucrose solution followed by freeze-drying or convective drying resulted in a glass transition temperature (T-g) that was higher than the

  18. Sucrose Treated Carbon Nanotube and Graphene Yarns and Sheets

    Science.gov (United States)

    Sauti, Godfrey (Inventor); Kim, Jae-Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor)

    2017-01-01

    Consolidated carbon nanotube or graphene yarns and woven sheets are consolidated through the formation of a carbon binder formed from the dehydration of sucrose. The resulting materials, on a macro-scale are lightweight and of a high specific modulus and/or strength. Sucrose is relatively inexpensive and readily available, and the process is therefore cost-effective.

  19. Sucrose/bovine serum albumin mediated biomimetic crystallization

    Indian Academy of Sciences (India)

    To understand the role of the sucrose/bovine serum albumin system in the biomineralization process, we have tested the influence of different concentration of the sucrose/bovine serum albumin (BSA) on calcium carbonate (CaCO3) precipitation. The CaCO3 crystals were characterized by scanning electron microscope ...

  20. Kestose:sucrose fructosyl transfer - a potential problem in the investigation of fructan and sucrose metabolism

    International Nuclear Information System (INIS)

    Kanabus, J.; Carpita, N.C.; Housley, T.L.

    1990-01-01

    Wheat leaves can be induced by excision to produce fructans. Fructose residues of newly made oligofructans in leaves labeled in vivo with 14 CO 2 are not equally labeled. We report here on a fructosyl transferase activity in wheat leaves catalyzing the reaction: G * -F * + G-F-F = G * -F * -F + G-F. This activity, described previously in J. artichoke was attributed to fructan:fructan fructosyl transferase (FFT). The rate of this reaction in vitro is much higher than that of net kestose synthesis by SST. Hence, appearance of labeled 1-kestose from sucrose may not be an accurate measure of SST, but a curious reshuffling of hexoses between pools of 1-kestose and sucrose

  1. Modeling the vacuolar storage of malate shed lights on pre- and post-harvest fruit acidity.

    Science.gov (United States)

    Etienne, Audrey; Génard, Michel; Lobit, Philippe; Bugaud, Christophe

    2014-11-18

    Malate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. Several studies suggest that malate accumulation in fruit cells is controlled at the level of vacuolar storage. However, the regulation of vacuolar malate storage throughout fruit development, and the origins of the phenotypic variability of the malate concentration within fruit species remain to be clarified. In the present study, we adapted the mechanistic model of vacuolar storage proposed by Lobit et al. in order to study the accumulation of malate in pre and postharvest fruits. The main adaptation concerned the variation of the free energy of ATP hydrolysis during fruit development. Banana fruit was taken as a reference because it has the particularity of having separate growth and post-harvest ripening stages, during which malate concentration undergoes substantial changes. Moreover, the concentration of malate in banana pulp varies greatly among cultivars which make possible to use the model as a tool to analyze the genotypic variability. The model was calibrated and validated using data sets from three cultivars with contrasting malate accumulation, grown under different fruit loads and potassium supplies, and harvested at different stages. The model predicted the pre and post-harvest dynamics of malate concentration with fairly good accuracy for the three cultivars (mean RRMSE = 0.25-0.42). The sensitivity of the model to parameters and input variables was analyzed. According to the model, vacuolar composition, in particular potassium and organic acid concentrations, had an important effect on malate accumulation. The model suggested that rising temperatures depressed malate accumulation. The model also helped distinguish differences in malate concentration among the three cultivars and between the pre and post-harvest stages by highlighting the probable importance of proton pump activity and particularly of the free

  2. Identification and Functional Characterization of Sugarcane Invertase Inhibitor (ShINH1: A Potential Candidate for Reducing Pre- and Post-harvest Loss of Sucrose in Sugarcane

    Directory of Open Access Journals (Sweden)

    Suresha G. Shivalingamurthy

    2018-05-01

    Full Text Available In sugarcane, invertase enzymes play a key role in sucrose accumulation and are also involved in futile reactions where sucrose is continuously degraded during the pre- and post-harvest period, thereby reducing sugar yield and recovery. Invertase inhibitor (INVINH proteins play a key role in post-translation regulation of plant invertases through which sucrose hydrolysis is controlled. INVINH proteins are small (18 kDa members of the pectin methylesterase inhibitor superfamily and they are moderately conserved across plants. In the present study, we identified two INVINH genes from sugarcane, ShINH1 and ShINH2. In silico characterization of the encoded proteins revealed 43% sequence identity at the amino acid level, confirming the non-allelic nature of the proteins. The presence of putative signal peptide and subcellular targeting sequences revealed that ShINH1 and ShINH2 likely have apoplasmic and vacuolar localization, respectively. Experimental visualization of ShINH1–GFP revealed that ShINHI is indeed exported to the apoplast. Differential tissue-specific and developmental expression of ShINH1 between leaf, stalk, flower and root suggest that it plays a role in controlling source-sink metabolic regulation during sucrose accumulation in sugarcane. ShINH1 is expressed at relatively high levels in leaves and stalk compared to flowers and roots, and expression decreases significantly toward internodal maturity during stalk development. ShINH1 is expressed at variable levels in flowers with no specific association to floral maturity. Production of recombinant ShINH1 enabled experimental validation of protein function under in vitro conditions. Recombinant ShINH1 potently inhibited acid invertase (IC50 22.5 nM, making it a candidate for controlling pre- and post-harvest deterioration of sucrose in sugarcane. Our results indicate that ShINH1 and ShINH2 are likely to play a regulatory role in sucrose accumulation and contribute to the improvement

  3. Transportation

    National Research Council Canada - National Science Library

    Adams, James; Carr, Ron; Chebl, Maroun; Coleman, Robert; Costantini, William; Cox, Robert; Dial, William; Jenkins, Robert; McGovern, James; Mueller, Peter

    2006-01-01

    ...., trains, ships, etc.) and maximizing intermodal efficiency. A healthy balance must be achieved between the flow of international commerce and security requirements regardless of transportation mode...

  4. Identification of a probable pore-forming domain in the multimeric vacuolar anion channel AtALMT9.

    Science.gov (United States)

    Zhang, Jingbo; Baetz, Ulrike; Krügel, Undine; Martinoia, Enrico; De Angeli, Alexis

    2013-10-01

    Aluminum-activated malate transporters (ALMTs) form an important family of anion channels involved in fundamental physiological processes in plants. Because of their importance, the role of ALMTs in plant physiology is studied extensively. In contrast, the structural basis of their functional properties is largely unknown. This lack of information limits the understanding of the functional and physiological differences between ALMTs and their impact on anion transport in plants. This study aimed at investigating the structural organization of the transmembrane domain of the Arabidopsis (Arabidopsis thaliana) vacuolar channel AtALMT9. For that purpose, we performed a large-scale mutagenesis analysis and found two residues that form a salt bridge between the first and second putative transmembrane α-helices (TMα1 and TMα2). Furthermore, using a combination of pharmacological and mutagenesis approaches, we identified citrate as an "open channel blocker" of AtALMT9 and used this tool to examine the inhibition sensitivity of different point mutants of highly conserved amino acid residues. By this means, we found a stretch within the cytosolic moiety of the TMα5 that is a probable pore-forming domain. Moreover, using a citrate-insensitive AtALMT9 mutant and biochemical approaches, we could demonstrate that AtALMT9 forms a multimeric complex that is supposedly composed of four subunits. In summary, our data provide, to our knowledge, the first evidence about the structural organization of an ion channel of the ALMT family. We suggest that AtALMT9 is a tetramer and that the TMα5 domains of the subunits contribute to form the pore of this anion channel.

  5. Transportation

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Here is the decree of the thirtieth of July 1998 relative to road transportation, to trade and brokerage of wastes. It requires to firms which carry out a road transportation as well as to traders and to brokers of wastes to declare their operations to the prefect. The declaration has to be renewed every five years. (O.M.)

  6. Suppression of the vacuolar invertase gene delays senescent sweetening in chipping potatoes

    Science.gov (United States)

    Background: Potato chip processors require potato tubers that meet quality specifications for fried chip color, and color depends largely upon tuber sugar contents. At later times in storage, potatoes accumulate sucrose, glucose and fructose. This developmental process, senescent sweetening, manifes...

  7. Characterization of Sucrose Thin Films for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    S. L. Iconaru

    2011-01-01

    Full Text Available Sucrose is a natural osmolyte accumulated in the cells of organisms as they adapt to environmental stress. In vitro sucrose increases protein stability and forces partially unfolded structures to refold. Thin films of sucrose (C12H22O11 were deposited on thin cut glass substrates by the thermal evaporation technique (P∼10−5 torr. Characteristics of thin films were put into evidence by Fourier Transform Infrared Spectroscopy (FTIR, X-ray Photoelectron Spectroscopy (XPS, scanning electron microscopy (SEM, and differential thermal analysis and thermal gravimetric analysis (TG/DTA. The experimental results confirm a uniform deposition of an adherent layer. In this paper we present a part of the characteristics of sucrose thin films deposited on glass in medium vacuum conditions, as a part of a culture medium for osteoblast cells. Osteoblast cells were used to determine proliferation, viability, and cytotoxicity interactions with sucrose powder and sucrose thin films. The osteoblast cells have been provided from the American Type Culture Collection (ATCC Centre. The outcome of this study demonstrated the effectiveness of sucrose thin films as a possible nontoxic agent for biomedical applications.

  8. Sucrose and IQ induced mutations in rat colon by independent

    DEFF Research Database (Denmark)

    Hansen, Max; Hald, M. T.; Autrup, H.

    2004-01-01

    Sucrose-rich diets have repeatedly been observed to have co-carcinogenic actions in colon and liver of rats and to increase the number of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) induced aberrant crypt foci in rat colon. To investigate a possible interaction between sucrose and IQ...... on the genotoxicity in rat liver and colon, we gave Big Blue rats(TM) a diet containing sucrose (0%, 3.45% or 13.4% w/w) and/or IQ (70 ppm) for a period of 3 weeks. Sucrose and IQ increased the mutation frequency in the colon. The effect of combined treatments with IQ and sucrose on the mutation frequencies...... was additive indicating that sucrose and IQ act independently. This was supported by the mutation spectra where sucrose expands the background mutations in the colon, whereas IQ, in other studies, more specifically has induced G:C --> T:A transversions. In the liver IQ increased the mutation frequency, whereas...

  9. Transportation

    National Research Council Canada - National Science Library

    Allshouse, Michael; Armstrong, Frederick Henry; Burns, Stephen; Courts, Michael; Denn, Douglas; Fortunato, Paul; Gettings, Daniel; Hansen, David; Hoffman, D. W; Jones, Robert

    2007-01-01

    .... The ability of the global transportation industry to rapidly move passengers and products from one corner of the globe to another continues to amaze even those wise to the dynamics of such operations...

  10. Sucrose tricarboxylate by sonocatalysed TEMPO-mediated oxidation.

    Science.gov (United States)

    Lemoine, S; Thomazeau, C; Joannard, D; Trombotto, S; Descotes, G; Bouchu, A; Queneau, Y

    2000-06-16

    Oxidation of sucrose by the NaOCl/TEMPO system provided sucrose tricarboxylate without the addition of sodium bromide as co-catalyst when high-frequency (500 kHz) ultrasound was applied, in contrast to very limited conversion without sonication. In the presence of sodium bromide, sonication also caused acceleration of the oxidation. The rate increase due to sonication of the oxidant system prior to sucrose addition suggests that ultrasound acts at the level of the formation of the nitrosonium ion, the active oxidising species in the catalytic cycle.

  11. Molecular cloning, functional expression and subcellular localization of two putative vacuolar voltage-gated chloride channels in rice (Oryza sativa L.).

    Science.gov (United States)

    Nakamura, Atsuko; Fukuda, Atsunori; Sakai, Shingo; Tanaka, Yoshiyuki

    2006-01-01

    We isolated two cDNA clones (OsCLC-1 and OsCLC-2) homologous to tobacco CLC-Nt1, which encodes a voltage-gated chloride channel, from rice (Oryza sativa L. ssp. japonica, cv. Nipponbare). The deduced amino acid sequences were highly conserved (87.9% identity with each other). Southern blot analysis of the rice genomic DNA revealed that OsCLC-1 and OsCLC-2 were single-copy genes on chromosomes 4 and 2, respectively. OsCLC-1 was expressed in most tissues, whereas OsCLC-2 was expressed only in the roots, nodes, internodes and leaf sheaths. The level of expression of OsCLC-1, but not of OsCLC-2, was increased by treatment with NaCl. Both genes could partly substitute for GEF1, which encodes the sole chloride channel in yeast, by restoring growth under ionic stress. These results indicate that both genes are chloride channel genes. The proteins from both genes were immunochemically detected in the tonoplast fraction. Tagged synthetic green fluorescent protein which was fused to OsCLC-1 or OsCLC-2 localized in the vacuolar membranes. These results indicate that the proteins may play a role in the transport of chloride ions across the vacuolar membrane. We isolated loss-of-function mutants of both genes from a panel of rice mutants produced by the insertion of a retrotransposon, Tos17, in the exon region, and found inhibition of growth at all life stages.

  12. Molecular motions in sucrose-PVP and sucrose-sorbitol dispersions-II. Implications of annealing on secondary relaxations.

    Science.gov (United States)

    Bhattacharya, Sisir; Bhardwaj, Sunny P; Suryanarayanan, Raj

    2014-10-01

    To determine the effect of annealing on the two secondary relaxations in amorphous sucrose and in sucrose solid dispersions. Sucrose was co-lyophilized with either PVP or sorbitol, annealed for different time periods and analyzed by dielectric spectroscopy. In an earlier investigation, we had documented the effect of PVP and sorbitol on the primary and the two secondary relaxations in amorphous sucrose solid dispersions (1). Here we investigated the effect of annealing on local motions, both in amorphous sucrose and in the dispersions. The average relaxation time of the local motion (irrespective of origin) in sucrose, decreased upon annealing. However, the heterogeneity in relaxation time distribution as well as the dielectric strength decreased only for β1- (the slower relaxation) but not for β2-relaxations. The effect of annealing on β2-relaxation times was neutralized by sorbitol while PVP negated the effect of annealing on both β1- and β2-relaxations. An increase in local mobility of sucrose brought about by annealing could be negated with an additive.

  13. Listeria monocytogenes switches from dissemination to persistence by adopting a vacuolar lifestyle in epithelial cells

    Science.gov (United States)

    Mitchell, Gabriel

    2017-01-01

    Listeria monocytogenes causes listeriosis, a foodborne disease that poses serious risks to fetuses, newborns and immunocompromised adults. This intracellular bacterial pathogen proliferates in the host cytosol and exploits the host actin polymerization machinery to spread from cell-to-cell and disseminate in the host. Here, we report that during several days of infection in human hepatocytes or trophoblast cells, L. monocytogenes switches from this active motile lifestyle to a stage of persistence in vacuoles. Upon intercellular spread, bacteria gradually stopped producing the actin-nucleating protein ActA and became trapped in lysosome-like vacuoles termed Listeria-Containing Vacuoles (LisCVs). Subpopulations of bacteria resisted degradation in LisCVs and entered a slow/non-replicative state. During the subculture of host cells harboring LisCVs, bacteria showed a capacity to cycle between the vacuolar and the actin-based motility stages. When ActA was absent, such as in ΔactA mutants, vacuolar bacteria parasitized host cells in the so-called “viable but non-culturable” state (VBNC), preventing their detection by conventional colony counting methods. The exposure of infected cells to high doses of gentamicin did not trigger the formation of LisCVs, but selected for vacuolar and VBNC bacteria. Together, these results reveal the ability of L. monocytogenes to enter a persistent state in a subset of epithelial cells, which may favor the asymptomatic carriage of this pathogen, lengthen the incubation period of listeriosis, and promote bacterial survival during antibiotic therapy. PMID:29190284

  14. Macropinosomes are Key Players in Early Shigella Invasion and Vacuolar Escape in Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Allon Weiner

    2016-05-01

    Full Text Available Intracellular pathogens include all viruses, many bacteria and parasites capable of invading and surviving within host cells. Key to survival is the subversion of host cell pathways by the pathogen for the purpose of propagation and evading the immune system. The intracellular bacterium Shigella flexneri, the causative agent of bacillary dysentery, invades host cells in a vacuole that is subsequently ruptured to allow growth of the pathogen within the host cytoplasm. S. flexneri invasion has been classically described as a macropinocytosis-like process, however the underlying details and the role of macropinosomes in the intracellular bacterial lifestyle have remained elusive. We applied dynamic imaging and advanced large volume correlative light electron microscopy (CLEM to study the highly transient events of S. flexneri's early invasion into host epithelial cells and elucidate some of its fundamental features. First, we demonstrate a clear distinction between two compartments formed during the first step of invasion: the bacterial containing vacuole and surrounding macropinosomes, often considered identical. Next, we report a functional link between macropinosomes and the process of vacuolar rupture, demonstrating that rupture timing is dependent on the availability of macropinosomes as well as the activity of the small GTPase Rab11 recruited directly to macropinosomes. We go on to reveal that the bacterial containing vacuole and macropinosomes come into direct contact at the onset of vacuolar rupture. Finally, we demonstrate that S. flexneri does not subvert pre-existing host endocytic vesicles during the invasion steps leading to vacuolar rupture, and propose that macropinosomes are the major compartment involved in these events. These results provide the basis for a new model of the early steps of S. flexneri epithelial cell invasion, establishing a different view of the enigmatic process of cytoplasmic access by invasive bacterial

  15. Sucrose or sucrose and caffeine differentially impact memory and anxiety-like behaviours, and alter hippocampal parvalbumin and doublecortin.

    Science.gov (United States)

    Xu, Tanya J; Reichelt, Amy C

    2018-04-11

    Caffeinated sugar-sweetened "energy" drinks are a subset of soft drinks that are popular among young people worldwide. High sucrose diets impair cognition and alter aspects of emotional behaviour in rats, however, little is known about sucrose combined with caffeine. Rats were allocated to 2 h/day 10% sucrose (Suc), 10% sucrose plus 0.04% caffeine (CafSuc) or control (water) conditions. The addition of caffeine to sucrose appeared to increase the rewarding aspect of sucrose, as the CafSuc group consumed more solution than the Suc group. After 14 days of intermittent Suc or CafSuc access, anxiety was assessed in the elevated plus maze (EPM) prior to their daily solution access, whereby CafSuc and Suc rats spent more time in the closed arms, indicative of increased anxiety. Following daily solution access, CafSuc, but not Suc, rats showed reduced anxiety-like behaviour in the open-field. Control and CafSuc rats displayed intact place and long-term object memory, while Suc showed impaired memory performance. Sucrose reduced parvalbumin immunoreactivity in the hippocampus, but no differences were observed between Control and CafSuc conditions. Parvalbumin reactivity in the basolateral amygdala did not differ between conditions. Reduced doublecortin immunoreactivity in the dentate gyrus relative to controls was seen in the CafSuc, but not Suc, treatment conditions. These findings indicate that the addition of caffeine to sucrose attenuated cognitive deficits. However, the addition of caffeine to sucrose evoked anxiety-like responses under certain testing conditions, suggesting that frequent consumption of caffeinated energy drinks may promote emotional alterations and brain changes compared to standard soft drinks. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Inorganic polyphosphate in the yeast Saccharomyces cerevisiae with a mutation disturbing the function of vacuolar ATPase.

    Science.gov (United States)

    Tomaschevsky, A A; Ryasanova, L P; Kulakovskaya, T V; Kulaev, I S

    2010-08-01

    A mutation in the vma2 gene disturbing V-ATPase function in the yeast Saccharomyces cerevisiae results in a five- and threefold decrease in inorganic polyphosphate content in the stationary and active phases of growth on glucose, respectively. The average polyphosphate chain length in the mutant cells is decreased. The mutation does not prevent polyphosphate utilization during cultivation in a phosphate-deficient medium and recovery of its level on reinoculation in complete medium after phosphate deficiency. The content of short chain acid-soluble polyphosphates is recovered first. It is supposed that these polyphosphates are less dependent on the electrochemical gradient on the vacuolar membrane.

  17. Transient anterior subcapsular vacuolar change of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation.

    Science.gov (United States)

    Chung, Jin Kwon; Shin, Jin Hee; Lee, Sung Jin

    2013-10-25

    We present two cases of transient vacuolar changes in the anterior subcapsular space of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation. Implantable collamer lenses (ICL) were implanted in healthy myopic patients. Vacuolar changes developed just after the irrigating procedure through the narrow space between the ICL and the crystalline lens. Slit-lamp examinations and spectral domain optical coherence tomography showed bleb-like lesions in the anterior subcapsular space of one eye in each case, though the lesions gradually improved without visual deterioration. Consequently, the lesions turned into a few anterior subcapsular small faint opacities. Direct irrigation of the narrow space confined by the ICL and the crystalline lens is at risk for the development of vacuolar changes in the crystalline lens. The observed spontaneous reversal indicates that surgeons should not rush to surgical intervention but rather opt for close follow over several weeks.

  18. EFFECTS OF SUCROSE AND VEGETABLE OIL ON PROPERTIES ...

    African Journals Online (AJOL)

    nindjin.c

    diameter) to minimize the formation of air bubbles included in the film. ..... polymeric chains was more difficult to make due to the molecule structure of ... observed during storage, due to sucrose addition to cassava starch-xanthan gum films,.

  19. Effects of salinity on sucrose metabolism during tomato fruit ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-08

    Feb 8, 2010 ... (fructose and glucose) accumulated to higher levels and the content of ... But the effects of salinity treatment on sucrose phosphate synthase activities were ... analysis. Sink strength was expressed as the dry matter accumu-.

  20. Effects of salinity on sucrose metabolism during tomato fruit ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-08

    Feb 8, 2010 ... But the effects of salinity treatment on sucrose phosphate synthase activities were weak under the ... The growth of different sink organs depends firstly on the use of ..... isoforms, location and regulatory mechanisms by endo-.

  1. Sucrose effect on broomrape (Orobanche crenata) development on ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... Key words: Sucrose, Orobanche crenata, Vicia narbonensis and broomrape control. INTRODUCTION ... and forage legume used for livestock feed in the .... the yield of faba bean significantly (Kukula and Masri, 1984). More-.

  2. Gene structure, phylogeny and expression profile of the sucrose ...

    Indian Academy of Sciences (India)

    Gene structure, phylogeny and expression profile of the sucrose synthase gene family in .... 24, 701–713. Bate N. and Twell D. 1998 Functional architecture of a late pollen .... Manzara T. and Gruissem W. 1988 Organization and expression.

  3. Cloning and expression of pineapple sucrose- phosphate synthase ...

    African Journals Online (AJOL)

    hope&shola

    2010-12-06

    Dec 6, 2010 ... phosphate; EDTA, ethylene diamine tetraacetic acid; Ivr, invertase; SS .... phenolics, tannins and artifacts due to differences of tissue composition ..... Banana sucrose-phosphate synthase gene expression during fruit ripening.

  4. Sucrose Improves Insecticide Activity Against Drosophila suzukii (Diptera: Drosophilidae).

    Science.gov (United States)

    Cowles, Richard S; Rodriguez-Saona, Cesar; Holdcraft, Robert; Loeb, Gregory M; Elsensohn, Johanna E; Hesler, Steven P

    2015-04-01

    The addition of sucrose to insecticides targeting spotted wing drosophila, Drosophila suzukii (Matsumura), enhanced lethality in laboratory, semifield, and field tests. In the laboratory, 0.1% sucrose added to a spray solution enhanced spotted wing drosophila feeding. Flies died 120 min earlier when exposed to spinosad residues at label rates enhanced with sucrose. Added sucrose reduced the LC50 for dried acetamiprid residues from 82 to 41 ppm in the spray solution. Laboratory bioassays of spotted wing drosophila mortality followed exposure to grape and blueberry foliage and/or fruit sprayed and aged in the field. On grape foliage, the addition of 2.4 g/liter of sugar with insecticide sprays resulted in an 11 and 6% increase of spotted wing drosophila mortality at 1 and 2 d exposures to residues, respectively, averaged over seven insecticides with three concentrations. In a separate experiment, spinetoram and cyantraniliprole reduced by 95-100% the larval infestation of blueberries, relative to the untreated control, 7 d after application at labeled rates when applied with 1.2 g/liter sucrose in a spray mixture, irrespective of rainfall; without sucrose infestation was reduced by 46-91%. Adding sugar to the organically acceptable spinosyn, Entrust, reduced larval infestation of strawberries by >50% relative to without sugar for five of the six sample dates during a season-long field trial. In a small-plot field test with blueberries, weekly applications in alternating sprays of sucrose plus reduced-risk insecticides, spinetoram or acetamiprid, reduced larval infestation relative to the untreated control by 76%; alternating bifenthrin and phosmet (without sucrose) reduced infestation by 65%. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Sistemas primários de transporte de prótons integram os mecanismos de desintoxicação do mesotrione em plantas de milho Proton transport primary systems used as mechanisms of mesotrione detoxification in corn plants

    Directory of Open Access Journals (Sweden)

    J. Ogliari

    2009-01-01

    ão variaram mais do que 20 a 60% das atividades obtidas em vesículas de membranas oriundas de plantas não tratadas (controle. Os resultados demonstraram que o mesotrione promove uma ativação diferencial dos principais sistemas primários de transporte de H+, indicando que essas bombas iônicas são enzimas transportadoras essenciais aos mecanismos relacionados com o processo de desintoxicação das plantas de milho, possivelmente ao energizar a compartimentalização das moléculas do herbicida mesotrione no vacúolo ou a exceção celular através das membranas plasmáticas.The herbicide Mesotrione herbicides are very effective in the control of a wide range of weeds that infest corn (Zea mays fields. However, the biochemical and molecular bases of corn seedling tolerance to this herbicide have not been established so far. To understand the mechanisms of mesotrione detoxification in corn plants, the activities of the main primary proton (H+ ion transport systems of the vacuolar and plasma membranes (H+-ATPases V- and P-types, and H+-PPase of the cells from different tissues were analyzed, after post-emergence herbicide application. Thus, cell fractionation procedures on root, leaf and mesocotyl tissues were performed using differential membrane vesicle centrifugation and purification in sucrose density gradient. Hydrolytic activities of the proton pumps were measured by using a colorimetric method for phosphate released through enzymatic hydrolysis of the substrates adenosine-5'-triphosphate (ATP and pyrophosphate (PPi. Photosynthetic parameters were analyzed as physiological markers of the different stages of plant detoxification. Such analysis demonstrated that, three days after herbicide application (DAA, mesotrione induced a reduction in the photosynthetic rate and Fv/Fm ratio, but no significant effect could be found after the fifth DAA. These data suggest that the treatment with mesotrione promoted a spatial and temporal regulation of the H+ pump activities. In all

  6. Evaluation and comparison of antinociceptive activity of aspartame with sucrose.

    Science.gov (United States)

    Rani, Seema; Gupta, Mahesh C

    2012-01-01

    Artificial sweeteners are low-calorie substances used to sweeten a wide variety of foods. At present they are used increasingly not only by diabetics, but also by the general public as a mean of controlling the weight. This study was carried out to evaluate and compare antinociceptive activity of the artificial sweeteners, aspartame and sucrose and to study the mechanisms involved in this analgesic activity. Forty eight white albino Wistar rats were divided into two groups of 24 rats each. Group 1 received sucrose and group 2 received aspartame solution ad libitum for 14 days as their only source of liquid. On 14(th) day, both groups of rats were divided into 3 subgroups having 8 rats each. Group Ia and IIa served as control. Group Ib and IIb were given naloxone and Ic and IIc received ketanserin, the opioid and serotonergic receptor antagonists, respectively. Tail withdrawal latencies (tail flick analgesiometer) and paw licking/jumping latencies (Eddy's hot plate method) were increased significantly in both aspartame and sucrose group. The analgesia produced by aspartame was comparable with sucrose. The opioid receptor antagonist naloxone and the 5-HT(2A/2C) serotonergic receptor antagonist ketanserin partly reversed the antinociceptive effect of these sweeteners. Thus, the artificial sweetening agent aspartame showed antinociceptive activity like sucrose in rats. Reduction in antinociceptive activity of aspartame and sucrose by opioid and serotoninergic antagonists demonstrate the involvement of both opioid and serotonergic system.

  7. Glucose-responsive neurons of the paraventricular thalamus control sucrose-seeking behavior.

    Science.gov (United States)

    Labouèbe, Gwenaël; Boutrel, Benjamin; Tarussio, David; Thorens, Bernard

    2016-08-01

    Feeding behavior is governed by homeostatic needs and motivational drive to obtain palatable foods. Here, we identify a population of glutamatergic neurons in the paraventricular thalamus of mice that express the glucose transporter Glut2 (encoded by Slc2a2) and project to the nucleus accumbens. These neurons are activated by hypoglycemia and, in freely moving mice, their activation by optogenetics or Slc2a2 inactivation increases motivated sucrose-seeking but not saccharin-seeking behavior. These neurons may control sugar overconsumption in obesity and diabetes.

  8. A Dual Microscopy-Based Assay To Assess Listeria monocytogenes Cellular Entry and Vacuolar Escape.

    Science.gov (United States)

    Quereda, Juan J; Pizarro-Cerdá, Javier; Balestrino, Damien; Bobard, Alexandre; Danckaert, Anne; Aulner, Nathalie; Shorte, Spencer; Enninga, Jost; Cossart, Pascale

    2016-01-01

    Listeria monocytogenes is a Gram-positive bacterium and a facultative intracellular pathogen that invades mammalian cells, disrupts its internalization vacuole, and proliferates in the host cell cytoplasm. Here, we describe a novel image-based microscopy assay that allows discrimination between cellular entry and vacuolar escape, enabling high-content screening to identify factors specifically involved in these two steps. We first generated L. monocytogenes and Listeria innocua strains expressing a β-lactamase covalently attached to the bacterial cell wall. These strains were then incubated with HeLa cells containing the Förster resonance energy transfer (FRET) probe CCF4 in their cytoplasm. The CCF4 probe was cleaved by the bacterial surface β-lactamase only in cells inoculated with L. monocytogenes but not those inoculated with L. innocua, thereby demonstrating bacterial access to the host cytoplasm. Subsequently, we performed differential immunofluorescence staining to distinguish extracellular versus total bacterial populations in samples that were also analyzed by the FRET-based assay. With this two-step analysis, bacterial entry can be distinguished from vacuolar rupture in a single experiment. Our novel approach represents a powerful tool for identifying factors that determine the intracellular niche of L. monocytogenes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Decreased proteinase A excretion by strengthening its vacuolar sorting and weakening its constitutive secretion in Saccharomyces cerevisiae.

    Science.gov (United States)

    Chen, Yefu; Song, Lulu; Han, Yueran; Liu, Mingming; Gong, Rui; Luo, Weiwei; Guo, Xuewu; Xiao, Dongguang

    2017-01-01

    Proteinase A (PrA), encoded by PEP4 gene, is detrimental to beer foam stability. There are two transport pathways for the new synthesized PrA in yeast, sorting to the vacuole normally, or excreting out of the cells under stress conditions. They were designated as the Golgi-to-vacuole pathway and the constitutive secretory pathway, respectively. To reduce PrA excretion in some new way instead of its coding gene deletion, which had a negative effect on cell metabolism and beer fermentation, we modified the PrA transport based on these above two pathways. In the Golgi-to-vacuole pathway, after the verification that Vps10p is the dominant sorting receptor for PrA Golgi-to-vacuolar transportation by VPS10 deletion, VPS10 was then overexpressed. Furthermore, SEC5, encoding exocyst complexes' central subunit (Sec5p) in the constitutive secretory pathway, was deleted. The results show that PrA activity in the broth fermented with WGV10 (VPS10 overexpressing strain) and W∆SEC5 (SEC5 deletion strain) was lowered by 76.96 and 32.39%, compared with the parental strain W303-1A, at the end of main fermentation. There are negligible changes in fermentation performance between W∆SEC5 and W303-1A, whereas, surprisingly, WGV10 had a significantly improved fermentation performance compared with W303-1A. WGV10 has an increased growth rate, resulting in higher biomass and faster fermentation speed; finally, wort fermentation is performed thoroughly. The results show that the biomass production of WGV10 is always higher than that of W∆SEC5 and W303-1A at all stages of fermentation, and that ethanol production of WGV10 is 1.41-fold higher than that of W303-1A. Obviously, VPS10 overexpression is beneficial for yeast and is a more promising method for reduction of PrA excretion.

  10. Responding for sucrose and wheel-running reinforcement: effects of sucrose concentration and wheel-running reinforcer duration.

    Science.gov (United States)

    Belke, Terry W; Hancock, Stephanie D

    2003-03-01

    Six male albino rats were placed in running wheels and exposed to a fixed-interval 30-s schedule of lever pressing that produced either a drop of sucrose solution or the opportunity to run for a fixed duration as reinforcers. Each reinforcer type was signaled by a different stimulus. In Experiment 1, the duration of running was held constant at 15 s while the concentration of sucrose solution was varied across values of 0, 2.5. 5, 10, and 15%. As concentration decreased, postreinforcement pause duration increased and local rates decreased in the presence of the stimulus signaling sucrose. Consequently, the difference between responding in the presence of stimuli signaling wheel-running and sucrose reinforcers diminished, and at 2.5%, response functions for the two reinforcers were similar. In Experiment 2, the concentration of sucrose solution was held constant at 15% while the duration of the opportunity to run was first varied across values of 15, 45, and 90 s then subsequently across values of 5, 10, and 15 s. As run duration increased, postreinforcement pause duration in the presence of the wheel-running stimulus increased and local rates increased then decreased. In summary, inhibitory aftereffects of previous reinforcers occurred when both sucrose concentration and run duration varied; changes in responding were attributable to changes in the excitatory value of the stimuli signaling the two reinforcers.

  11. Transportation

    Science.gov (United States)

    2007-01-01

    Faculty ii INDUSTRY TRAVEL Domestic Assistant Deputy Under Secretary of Defense (Transportation Policy), Washington, DC Department of...developed between the railroad and trucking industries. Railroads: Today’s seven Class I freight railroad systems move 42% of the nation’s intercity ...has been successfully employed in London to reduce congestion and observed by this industry study during its travels . It is currently being

  12. Sucrose for analgesia in newborn infants undergoing painful procedures.

    Science.gov (United States)

    Stevens, Bonnie; Yamada, Janet; Ohlsson, Arne; Haliburton, Sarah; Shorkey, Allyson

    2016-07-16

    Administration of oral sucrose with and without non-nutritive sucking is the most frequently studied non-pharmacological intervention for procedural pain relief in neonates. To determine the efficacy, effect of dose, method of administration and safety of sucrose for relieving procedural pain in neonates as assessed by validated composite pain scores, physiological pain indicators (heart rate, respiratory rate, saturation of peripheral oxygen in the blood, transcutaneous oxygen and carbon dioxide (gas exchange measured across the skin - TcpO2, TcpCO2), near infrared spectroscopy (NIRS), electroencephalogram (EEG), or behavioural pain indicators (cry duration, proportion of time crying, proportion of time facial actions (e.g. grimace) are present), or a combination of these and long-term neurodevelopmental outcomes. We used the standard methods of the Cochrane Neonatal. We performed electronic and manual literature searches in February 2016 for published randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, Issue 1, 2016), MEDLINE (1950 to 2016), EMBASE (1980 to 2016), and CINAHL (1982 to 2016). We did not impose language restrictions. RCTs in which term or preterm neonates (postnatal age maximum of 28 days after reaching 40 weeks' postmenstrual age), or both, received sucrose for procedural pain. Control interventions included no treatment, water, glucose, breast milk, breastfeeding, local anaesthetic, pacifier, positioning/containing or acupuncture. Our main outcome measures were composite pain scores (including a combination of behavioural, physiological and contextual indicators). Secondary outcomes included separate physiological and behavioural pain indicators. We reported a mean difference (MD) or weighted MD (WMD) with 95% confidence intervals (CI) using the fixed-effect model for continuous outcome measures. For categorical data we used risk ratio (RR) and risk difference. We assessed

  13. Ligand recognition and domain structure of Vps10p, a vacuolar protein sorting receptor in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Jørgensen, M U; Emr, S D; Winther, Jakob R.

    1999-01-01

    Vp10p is a receptor that sorts several different vacuolar proteins by cycling between a late Golgi compartment and the endosome. The cytoplasmic tail of Vps10p is necessary for the recycling, whereas the lumenal domain is predicted to interact with the soluble ligands. We have studied ligand bind...

  14. Mutational analysis of the vacuolar sorting signal of procarboxypeptidase Y in yeast shows a low requirement for sequence conservation

    DEFF Research Database (Denmark)

    van Voorst, F; Kielland-Brandt, Morten; Winther, Jakob R.

    1996-01-01

    The core of the vacuolar targeting signal of yeast carboxypeptidase Y (CPY) is recognized by the receptor Vps10p and consists of four contiguous amino acid residues, Gln24-Arg-Pro-Leu27, near the amino terminus of the propeptide (Valls, L.A., Winther, J. R., and Stevens, T. H. (1990) J. Cell Biol...

  15. The patatin-like protein from the latex of Hevea brasiliensis (Hev b 7) is not a vacuolar protein

    NARCIS (Netherlands)

    Jekel, PA; Hofsteenge, J; Beintema, JJ

    Upon centrifugation, rubber latex is divided into a layer of rubber particles, the cytosol, and the lutoid-body fraction, which is of vacuolar origin. One of the proteins isolated from the lutoid-body fraction is a protein with a molecular mass of 43 kDa, which has esterase activity on

  16. Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

    Directory of Open Access Journals (Sweden)

    Daniel Rios Garza

    Full Text Available The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics.

  17. Drinking sucrose enhances quinpirole-induced yawning in rats.

    Science.gov (United States)

    Baladi, Michelle G; Newman, Amy H; Thomas, Yvonne M; France, Charles P

    2011-12-01

    Food and drugs can activate brain dopamine systems and sensitivity to the effects of drugs acting on those systems is influenced by amount and content of food consumed. This study examined the effects of drinking sucrose on behavioral effects of the direct-acting dopamine receptor agonist quinpirole. Male Sprague-Dawley rats (n=6/group) had free access to water or 10% sucrose and quinpirole dose-response curves (yawning and hypothermia) were generated weekly for 8 weeks. Subsequently, all rats drank water for 8 weeks with quinpirole dose-response curves determined on weeks 9, 10, and 16. In rats drinking sucrose, the ascending (D3 receptor-mediated), but not descending (D2 receptor-mediated), limb of the yawning dose-response curve shifted leftward. The D3 receptor-selective antagonist PG01037 shifted the ascending limb of the dose-response curve to the right in all rats. When rats that previously drank sucrose drank water, their sensitivity to quinpirole did not return to normal. Quinpirole-induced hypothermia was not different between groups. These data show that drinking sucrose increases sensitivity to a dopamine D3, but not D2, receptor-mediated effect and that this change is long lasting. Dopamine receptors mediate the effects of many drugs and the actions of those drugs are likely impacted by dietary factors.

  18. SUCROSE SYNTHASE: ELUCIDATION OF COMPLEX POST-TRANSLATIONAL REGULATORY MECHANISMS

    Energy Technology Data Exchange (ETDEWEB)

    Steven C. Huber

    2009-05-12

    Studies have focused on the enzyme sucrose synthase, which plays an important role in the metabolism of sucrose in seeds and tubers. There are three isoforms of SUS in maize, referred to as SUS1, SUS-SH1, and SUS2. SUS is generally considered to be tetrameric protein but recent evidence suggests that SUS can also occur as a dimeric protein. The formation of tetrameric SUS is regulated by sucrose concentration in vitro and this could also be an important factor in the cellular localization of the protein. We found that high sucrose concentrations, which promote tetramer formation, also inhibit the binding of SUS1 to actin filaments in vitro. Previously, high sucrose concentrations were shown to promote SUS association with the plasma membrane. The specific regions of the SUS molecule involved in oligomerization are not known, but we identified a region of the SUS1 moelcule by bioinformatic analysis that was predicted to form a coiled coil. We demonstrated that this sequence could, in fact, self-associate as predicted for a coiled coil, but truncation analysis with the full-length recombinant protein suggested that it was not responsible for formation of dimers or tetramers. However, the coiled coil may function in binding of other proteins to SUS1. Overall, sugar availability may differentially influence the binding of SUS to cellular structures, and these effects may be mediated by changes in the oligomeric nature of the enzyme.

  19. Human NKCC2 cation–Cl– co-transporter complements lack of Vhc1 transporter in yeast vacuolar membranes

    Czech Academy of Sciences Publication Activity Database

    Petrezsélyová, Silvia; Domínguez, A.; Herynková, Pavla; Macias, J. F.; Sychrová, Hana

    2013-01-01

    Roč. 30, č. 10 (2013), s. 395-402 ISSN 0749-503X R&D Projects: GA MŠk(CZ) LC531; GA AV ČR(CZ) IAA500110801 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200110901 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : heterologous expression * CCC family * alkali-metal-cation tolerance * Saccharomyces cerevisiae * ion homeostasis Subject RIV: EE - Microbiology, Virology Impact factor: 1.742, year: 2013

  20. The Citrus transcription factor, CitERF13, regulates citric acid accumulation via a protein-protein interaction with the vacuolar proton pump, CitVHA-c4.

    Science.gov (United States)

    Li, Shao-jia; Yin, Xue-ren; Xie, Xiu-lan; Allan, Andrew C; Ge, Hang; Shen, Shu-ling; Chen, Kun-song

    2016-02-03

    Organic acids are essential to fruit flavor. The vacuolar H(+) transporting adenosine triphosphatase (V-ATPase) plays an important role in organic acid transport and accumulation. However, less is known of V-ATPase interacting proteins and their relationship with organic acid accumulation. The relationship between V-ATPase and citric acid was investigated, using the citrus tangerine varieties 'Ordinary Ponkan (OPK)' and an early maturing mutant 'Zaoshu Ponkan (ZPK)'. Five V-ATPase genes (CitVHA) were predicted as important to citric acid accumulation. Among the genes, CitVHA-c4 was observed, using a yeast two-hybrid screen, to interact at the protein level with an ethylene response factor, CitERF13. This was verified using bimolecular fluorescence complementation assays. A similar interaction was also observed between Arabidopsis AtERF017 (a CitERF13 homolog) and AtVHA-c4 (a CitVHA-c4 homolog). A synergistic effect on citric acid levels was observed between V-ATPase proteins and interacting ERFs when analyzed using transient over-expression in tobacco and Arabidopsis mutants. Furthermore, the transcript abundance of CitERF13 was concomitant with CitVHA-c4. CitERF13 or AtERF017 over-expression leads to significant citric acid accumulation. This accumulation was abolished in an AtVHA-c4 mutant background. ERF-VHA interactions appear to be involved in citric acid accumulation, which was observed in both citrus and Arabidopsis.

  1. A kinetic and microautoradiographic study of 14C-sucrose translocation into developing wheat grains

    International Nuclear Information System (INIS)

    Ning Wang; Fisher, D.B.

    1991-01-01

    The kinetics of 14 C-photosynthate import by developing wheat grains was followed after pulse-labeling the flag leaf with 14 CO 2 . Samples were collected from four successive points along the transport pathway to and within the grain: exuding aphid stylets on the peduncle, exuding grain pedicels, the grain crease tissues, and the liquid contents of the endosperm cavity. In addition, microautoradiographs were prepared of the grain crease tissues during movement of the 14 C pulse into the grain. At all times, sucrose accounted for 93 to 97% of the total 14 C present at all four sampling sites. The main features of the 14 C kinetics could be accounted for by a simple compartmental model consisting of sucrose pools in series. Microautoradiographs of the crease tissues showed fairly uniform labeling of vascular parenchyma at all times, with a sharp gradient in labeling across the chalaza to the nucellus. Thus the principal resistance to post-phloem solute transport through the maternal tissues appears to be in the symplastic pathway across the chalaza

  2. Deregulation of sucrose-controlled translation of a bZIP-type transcription factor results in sucrose accumulation in leaves.

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Thalor

    Full Text Available Sucrose is known to repress the translation of Arabidopsis thaliana AtbZIP11 transcript which encodes a protein belonging to the group of S (S--stands for small basic region-leucine zipper (bZIP-type transcription factor. This repression is called sucrose-induced repression of translation (SIRT. It is mediated through the sucrose-controlled upstream open reading frame (SC-uORF found in the AtbZIP11 transcript. The SIRT is reported for 4 other genes belonging to the group of S bZIP in Arabidopsis. Tobacco tbz17 is phylogenetically closely related to AtbZIP11 and carries a putative SC-uORF in its 5'-leader region. Here we demonstrate that tbz17 exhibits SIRT mediated by its SC-uORF in a manner similar to genes belonging to the S bZIP group of the Arabidopsis genus. Furthermore, constitutive transgenic expression of tbz17 lacking its 5'-leader region containing the SC-uORF leads to production of tobacco plants with thicker leaves composed of enlarged cells with 3-4 times higher sucrose content compared to wild type plants. Our finding provides a novel strategy to generate plants with high sucrose content.

  3. Deregulation of sucrose-controlled translation of a bZIP-type transcription factor results in sucrose accumulation in leaves.

    Science.gov (United States)

    Thalor, Sunil Kumar; Berberich, Thomas; Lee, Sung Shin; Yang, Seung Hwan; Zhu, Xujun; Imai, Ryozo; Takahashi, Yoshihiro; Kusano, Tomonobu

    2012-01-01

    Sucrose is known to repress the translation of Arabidopsis thaliana AtbZIP11 transcript which encodes a protein belonging to the group of S (S--stands for small) basic region-leucine zipper (bZIP)-type transcription factor. This repression is called sucrose-induced repression of translation (SIRT). It is mediated through the sucrose-controlled upstream open reading frame (SC-uORF) found in the AtbZIP11 transcript. The SIRT is reported for 4 other genes belonging to the group of S bZIP in Arabidopsis. Tobacco tbz17 is phylogenetically closely related to AtbZIP11 and carries a putative SC-uORF in its 5'-leader region. Here we demonstrate that tbz17 exhibits SIRT mediated by its SC-uORF in a manner similar to genes belonging to the S bZIP group of the Arabidopsis genus. Furthermore, constitutive transgenic expression of tbz17 lacking its 5'-leader region containing the SC-uORF leads to production of tobacco plants with thicker leaves composed of enlarged cells with 3-4 times higher sucrose content compared to wild type plants. Our finding provides a novel strategy to generate plants with high sucrose content.

  4. Apoptosis Gene Hunting Using Retroviral Expression Cloning: Identification of Vacuolar ATPase Subunit E

    Directory of Open Access Journals (Sweden)

    Claire L. Anderson

    2003-01-01

    Full Text Available Over the past 10-15 years there has been an explosion of interest in apoptosis. The delayed realisation that cell death is an essential part of life for any multicellular organism has meant that, despite the recent and rapid developments of the last decade, the precise biochemical pathways involved in apoptosis remain incomplete and potentially novel genes may, as yet, remain undiscovered. The hunt is therefore on to bridge the remaining gaps in our knowledge. Our contribution to this research effort utilises a functional cloning approach to isolate important regulatory genes involved in apoptosis. This mini-review focuses on the use and advantages of a retroviral expression cloning strategy and describes the isolation and identification of one such potential apoptosis regulatory gene, namely that encoding vacuolar ATPase subunit E.

  5. Targeting vacuolar H+-ATPases as a new strategy against cancer.

    Science.gov (United States)

    Fais, Stefano; De Milito, Angelo; You, Haiyan; Qin, Wenxin

    2007-11-15

    Growing evidence suggests a key role of tumor acidic microenvironment in cancer development, progression, and metastasis. As a consequence, the need for compounds that specifically target the mechanism(s) responsible for the low pH of tumors is increasing. Among the key regulators of the tumor acidic microenvironment, vacuolar H(+)-ATPases (V-ATPases) play an important role. These proteins cover a number of functions in a variety of normal as well as tumor cells, in which they pump ions across the membranes. We discuss here some recent results showing that a molecular inhibition of V-ATPases by small interfering RNA in vivo as well as a pharmacologic inhibition through proton pump inhibitors led to tumor cytotoxicity and marked inhibition of human tumor growth in xenograft models. These results propose V-ATPases as a key target for new strategies in cancer treatment.

  6. Expression analysis of Arabidopsis vacuolar sorting receptor 3 reveals a putative function in guard cells.

    Science.gov (United States)

    Avila, Emily L; Brown, Michelle; Pan, Songqin; Desikan, Radhika; Neill, Steven J; Girke, Thomas; Surpin, Marci; Raikhel, Natasha V

    2008-01-01

    Vacuolar sorting receptors (VSRs) are responsible for the proper targeting of soluble cargo proteins to their destination compartments. The Arabidopsis genome encodes seven VSRs. In this work, the spatio-temporal expression of one of the members of this gene family, AtVSR3, was determined by RT-PCR and promoter::reporter gene fusions. AtVSR3 was expressed specifically in guard cells. Consequently, a reverse genetics approach was taken to determine the function of AtVSR3 by using RNA interference (RNAi) technology. Plants expressing little or no AtVSR3 transcript had a compressed life cycle, bolting approximately 1 week earlier and senescing up to 2 weeks earlier than the wild-type parent line. While the development and distribution of stomata in AtVSR3 RNAi plants appeared normal, stomatal function was altered. The guard cells of mutant plants did not close in response to abscisic acid treatment, and the mean leaf temperatures of the RNAi plants were on average 0.8 degrees C lower than both wild type and another vacuolar sorting receptor mutant, atvsr1-1. Furthermore, the loss of AtVSR3 protein caused the accumulation of nitric oxide and hydrogen peroxide, signalling molecules implicated in the regulation of stomatal opening and closing. Finally, proteomics and western blot analyses of cellular proteins isolated from wild-type and AtVSR3 RNAi leaves showed that phospholipase Dgamma, which may play a role in abscisic acid signalling, accumulated to higher levels in AtVSR3 RNAi guard cells. Thus, AtVSR3 may play an important role in responses to plant stress.

  7. Vacuolar ATPase regulates surfactant secretion in rat alveolar type II cells by modulating lamellar body calcium.

    Directory of Open Access Journals (Sweden)

    Narendranath Reddy Chintagari

    2010-02-01

    Full Text Available Lung surfactant reduces surface tension and maintains the stability of alveoli. How surfactant is released from alveolar epithelial type II cells is not fully understood. Vacuolar ATPase (V-ATPase is the enzyme responsible for pumping H(+ into lamellar bodies and is required for the processing of surfactant proteins and the packaging of surfactant lipids. However, its role in lung surfactant secretion is unknown. Proteomic analysis revealed that vacuolar ATPase (V-ATPase dominated the alveolar type II cell lipid raft proteome. Western blotting confirmed the association of V-ATPase a1 and B1/2 subunits with lipid rafts and their enrichment in lamellar bodies. The dissipation of lamellar body pH gradient by Bafilomycin A1 (Baf A1, an inhibitor of V-ATPase, increased surfactant secretion. Baf A1-stimulated secretion was blocked by the intracellular Ca(2+ chelator, BAPTA-AM, the protein kinase C (PKC inhibitor, staurosporine, and the Ca(2+/calmodulin-dependent protein kinase II (CaMKII, KN-62. Baf A1 induced Ca(2+ release from isolated lamellar bodies. Thapsigargin reduced the Baf A1-induced secretion, indicating cross-talk between lamellar body and endoplasmic reticulum Ca(2+ pools. Stimulation of type II cells with surfactant secretagogues dissipated the pH gradient across lamellar bodies and disassembled the V-ATPase complex, indicating the physiological relevance of the V-ATPase-mediated surfactant secretion. Finally, silencing of V-ATPase a1 and B2 subunits decreased stimulated surfactant secretion, indicating that these subunits were crucial for surfactant secretion. We conclude that V-ATPase regulates surfactant secretion via an increased Ca(2+ mobilization from lamellar bodies and endoplasmic reticulum, and the activation of PKC and CaMKII. Our finding revealed a previously unrealized role of V-ATPase in surfactant secretion.

  8. Anharmonicity and hydrogen bonding in electrooptic sucrose crystal

    Science.gov (United States)

    Szostak, M. M.; Giermańska, J.

    1990-03-01

    The polarized absorption spectra of the sucrose crystal in the 5300 - 7300 cm -1 region have been measured. The assignments of all the eight OH stretching overtones are proposed and their mechanical anharmonicities are estimated. The discrepancies from the oriented gas model (OGM) in the observed relative band intensities, especially of the -CH vibrations, are assumed to be connected with vibronic couplings enhanced by the helical arrangement of molecules joined by hydrogen bondings. It seems that this kind of interactions might be important for the second harmonic generation (SHG) by the sucrose crystal.

  9. Abscisic acid and sucrose regulate tomato and strawberry fruit ripening through the abscisic acid-stress-ripening transcription factor.

    Science.gov (United States)

    Jia, Haifeng; Jiu, Songtao; Zhang, Cheng; Wang, Chen; Tariq, Pervaiz; Liu, Zhongjie; Wang, Baoju; Cui, Liwen; Fang, Jinggui

    2016-10-01

    Although great progress has been made towards understanding the role of abscisic acid (ABA) and sucrose in fruit ripening, the mechanisms underlying the ABA and sucrose signalling pathways remain elusive. In this study, transcription factor ABA-stress-ripening (ASR), which is involved in the transduction of ABA and sucrose signalling pathways, was isolated and analysed in the nonclimacteric fruit, strawberry and the climacteric fruit, tomato. We have identified four ASR isoforms in tomato and one in strawberry. All ASR sequences contained the ABA stress- and ripening-induced proteins and water-deficit stress-induced proteins (ABA/WDS) domain and all ASR transcripts showed increased expression during fruit development. The expression of the ASR gene was influenced not only by sucrose and ABA, but also by jasmonic acid (JA) and indole-3-acetic acid (IAA), and these four factors were correlated with each other during fruit development. ASR bound the hexose transporter (HT) promoter, which contained a sugar box that activated downstream gene expression. Overexpression of the ASR gene promoted fruit softening and ripening, whereas RNA interference delayed fruit ripening, as well as affected fruit physiological changes. Change in ASR gene expression influenced the expression of several ripening-related genes such as CHS, CHI, F3H, DFR, ANS, UFGT, PG, PL, EXP1/2, XET16, Cel1/2 and PME. Taken together, this study may provide new evidence on the important role of ASR in cross-signalling between ABA and sucrose to regulate tomato and strawberry fruit ripening. The findings of this study also provide new insights into the regulatory mechanism underlying fruit development. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  10. Variability in Phytochemicals, Á-Galactosides, Sucrose Composition ...

    African Journals Online (AJOL)

    In vitro protein digestibility varied significantly (P <0.05) among the bean varieties and had a positive significant correlation with sucrose content and negative correlations with trypsin inhibitors, tannins, lectins, á-galactosides and saponins. The correlation matrix indicated that variability in á-galactosides, the protein ...

  11. Gene structure, phylogeny and expression profile of the sucrose ...

    Indian Academy of Sciences (India)

    2015-09-16

    Sep 16, 2015 ... serine residue for phosphorylation by Ser/Thr protein kinase is indicated by a red star. The characteristic sucrose synthase domain (single underline) and a glycosyltransferases domain (double underline) were identified by the Interproscan algorithm (http://www.ebi.ac.uk/Tools/ pfa/iprscan/). 464. Journal of ...

  12. Sucrose Responsiveness, Learning Success, and Task Specialization in Ants

    Science.gov (United States)

    Perez, Margot; Rolland, Uther; Giurfa,, Martin; d'Ettorre, Patrizia

    2013-01-01

    Social insects possess remarkable learning capabilities, which are crucial for their ecological success. They also exhibit interindividual differences in responsiveness to environmental stimuli, which underlie task specialization and division of labor. Here we investigated for the first time the relationships between sucrose responsiveness,…

  13. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    In addition, the structure and thermodynamic properties of the modified starch were analyzed by Fourier transform infrared spectroscopy (FITR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Results: The properties of wheat starch changed greatly by adding different sucrose esters to their ...

  14. Radiation effect on sucrose content of inverted sugar

    International Nuclear Information System (INIS)

    Podadera, Priscilla; Sabato, Susy F.

    2007-01-01

    Inverted sugar is a mixture of sucrose, glucose and fructose used as an ingredient in the food and beverage industry. During production there are points of contamination by microorganisms that can modify the sugar properties and reduce shelf life. This work aims to consider one efficient technique in the sanitization of this ingredient with minimum alterations in the sugar ratios. Irradiation with Cobalt 60 is a technique with proven efficacy in the reduction of microorganisms. Samples of inverted sugar had been radiated with Cobalt 60, Gammacell type, at the CTR-IPEN, with doses of 5, 10, 20, 30 and 50 kGy, and dose rate of 3.88 kGy/h. The content of sucrose was determined by the Fehling method. The sample irradiated at highest dose presented the most intense reduction in the concentration of sucrose: 13% in comparison to the control. Irradiated samples up to 30 kGy did not presented statistical difference in relation to the control (p<0.05), indicating that radiation can be applied to the inverted sugar without significant alterations in the concentration of sucrose. (author)

  15. Radiation effect on sucrose content of inverted sugar

    Energy Technology Data Exchange (ETDEWEB)

    Podadera, Priscilla; Sabato, Susy F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes]. E-mails: ppodadera@yahoo.com.br; sfsabato@ipen.br

    2007-07-01

    Inverted sugar is a mixture of sucrose, glucose and fructose used as an ingredient in the food and beverage industry. During production there are points of contamination by microorganisms that can modify the sugar properties and reduce shelf life. This work aims to consider one efficient technique in the sanitization of this ingredient with minimum alterations in the sugar ratios. Irradiation with Cobalt 60 is a technique with proven efficacy in the reduction of microorganisms. Samples of inverted sugar had been radiated with Cobalt 60, Gammacell type, at the CTR-IPEN, with doses of 5, 10, 20, 30 and 50 kGy, and dose rate of 3.88 kGy/h. The content of sucrose was determined by the Fehling method. The sample irradiated at highest dose presented the most intense reduction in the concentration of sucrose: 13% in comparison to the control. Irradiated samples up to 30 kGy did not presented statistical difference in relation to the control (p<0.05), indicating that radiation can be applied to the inverted sugar without significant alterations in the concentration of sucrose. (author)

  16. Steroid hormone excretion is enhanced by sucrose feeding to rats

    International Nuclear Information System (INIS)

    Kruger, T.C.; Hsu, H.; Saunders, J.P.; Kim, S.S.; Given-Proctor, J.; Ahrens, R.A.

    1986-01-01

    The hypothesis tested was that feeding rats sucrose rather than invert sugar (50:50 mixture of glucose and fructose) or cornstarch would result in a more rapid excretion of intravenously injected 1,2- 3 H aldosterone or 1,2,6,7- 3 H cortisol. The three carbohydrate sources provided 45% of dietary energy when fed, respectively, to one of three groups of 10 male, Sprague Dawley rats. After 4 or 8 weeks of ad lib feeding of the three diets 5 μCI of 3 H-labeled hormones were injected intravenously and % recovery in urine and feces was measured for 4 days by liquid scintillation counting. Nearly 90% of the 3 H injected as 1,2- 3 H aldosterone was recovered over 4 days in the excreta of the sucrose fed rats. This recovery of 3 H from aldosterone was significantly greater (P 3 H from intravenously injected 1,2,6,7- 3 H cortisol followed a similar pattern. The authors anticipate that the excretion of all metabolic end products and xenobiotics excreted as glucuronides would be enhanced by sucrose feeding. Oxocarbonium ions from the glucose portion of sucrose digestion in the mammalian small intestine are thought to compete with oxocarbonium ions from the glucuronic acid portion of glucuronide hydrolysis. Such competition may slow glucuronide hydrolysis and promote glucuronide excretion, including the glucuronides derived from aldosterone and cortisol

  17. Synthesis of Fructooligosaccharides from Sucrose Using Inulinase from Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    Francisco Maugeri

    2007-01-01

    Full Text Available Fructooligosaccharides (FOS from sucrose, new alternative sweeteners with functional properties, also called soluble fibers, have a number of desirable characteristics such as low calories, no cariogenicity, and safety for diabetics and Bifidus stimulating factor. Fructooligosaccharides are also known as prebiotics, since they stimulate probiotic organisms. The production, as well as the application of food-grade fructooligosaccharides, has increased rapidly during last years. In this work, experimental factorial design has been applied to optimize the fructooligosaccharide synthesis conditions by inulinase from Kluyveromyces marxianus var. bulgaricus. The studied variables were: temperature, pH, sucrose and enzyme concentrations. According to the results, only temperature and sucrose concentrations have shown to be significant parameters. The syntheses of the fructooligosaccharides were carried out on stirred reactor and packed bed reactors, using free and immobilized enzymes, with the best conditions obtained from the experimental design. It has been shown that there is no significant difference between these processes. The final sugar concentrations can be tailor made by varying residence time in the reactor to cope with the different standard needs in food industries. A typical solution product consists of a mixture of fructose (155 g/L, glucose (155 g/L, sucrose (132 g/L and fructooligosaccharides (50 g/L. These concentrations are suitable for applications in most food industries, in products such as sweets, candies, chocolates and yogurts. Besides, the prebiotic function of fructooligosaccharides as stimulants of the beneficial intestinal flora will give the product a functional and differentiated feature.

  18. Sucrose/bovine serum albumin mediated biomimetic crystallization ...

    Indian Academy of Sciences (India)

    Administrator

    stereo-chemical, and structural interactions at the ... are considered to play a principal role in biominer- alization, but their function is still ... men powders were prepared for SEM analysis by coating each .... mixture of two components and micro-absorption ef- fects are ... With the addition of the BSA, protein–sucrose com-.

  19. Transitions in aqueous solutions of sucrose at subzero temperatures

    Czech Academy of Sciences Publication Activity Database

    Sikora, Antonín; Dupanov, V. O.; Kratochvíl, Jaroslav; Zámečník, J.

    2007-01-01

    Roč. 46, č. 1 (2007), s. 71-85 ISSN 0022-2348 R&D Projects: GA ČR(CZ) GA522/04/0384 Institutional research plan: CEZ:AV0Z40500505 Keywords : aqueous sucrose solutions * subzero temperature * glass transitions Subject RIV: BJ - Thermodynamics Impact factor: 0.809, year: 2007

  20. High affinity capture and concentration of quinacrine in polymorphonuclear neutrophils via vacuolar ATPase-mediated ion trapping: Comparison with other peripheral blood leukocytes and implications for the distribution of cationic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Caroline; Gagné, Valérie; Fernandes, Maria J.G.; Marceau, François, E-mail: francois.marceau@crchul.ulaval.ca

    2013-07-15

    Many cationic drugs are concentrated in acidic cell compartments due to low retro-diffusion of the protonated molecule (ion trapping), with an ensuing vacuolar and autophagic cytopathology. In solid tissues, there is evidence that phagocytic cells, e.g., histiocytes, preferentially concentrate cationic drugs. We hypothesized that peripheral blood leukocytes could differentially take up a fluorescent model cation, quinacrine, depending on their phagocytic competence. Quinacrine transport parameters were determined in purified or total leukocyte suspensions at 37 °C. Purified polymorphonuclear leukocytes (PMNLs, essentially neutrophils) exhibited a quinacrine uptake velocity inferior to that of lymphocytes, but a consistently higher affinity (apparent K{sub M} 1.1 vs. 6.3 μM, respectively). However, the vacuolar (V)-ATPase inhibitor bafilomycin A1 prevented quinacrine transport or initiated its release in either cell type. PMNLs capture most of the quinacrine added at low concentrations to fresh peripheral blood leukocytes compared with lymphocytes and monocytes (cytofluorometry). Accumulation of the autophagy marker LC3-II occurred rapidly and at low drug concentrations in quinacrine-treated PMNLs (significant at ≥ 2.5 μM, ≥ 2 h). Lymphocytes contained more LAMP1 than PMNLs, suggesting that the mass of lysosomes and late endosomes is a determinant of quinacrine uptake V{sub max}. PMNLs, however, exhibited the highest capacity for pinocytosis (uptake of fluorescent dextran into endosomes). The selectivity of quinacrine distribution in peripheral blood leukocytes may be determined by the collaboration of a non-concentrating plasma membrane transport mechanism, tentatively identified as pinocytosis in PMNLs, with V-ATPase-mediated concentration. Intracellular reservoirs of cationic drugs are a potential source of toxicity (e.g., loss of lysosomal function in phagocytes). - Highlights: • Quinacrine is concentrated in acidic organelles via V-ATPase-mediated ion

  1. High affinity capture and concentration of quinacrine in polymorphonuclear neutrophils via vacuolar ATPase-mediated ion trapping: Comparison with other peripheral blood leukocytes and implications for the distribution of cationic drugs

    International Nuclear Information System (INIS)

    Roy, Caroline; Gagné, Valérie; Fernandes, Maria J.G.; Marceau, François

    2013-01-01

    Many cationic drugs are concentrated in acidic cell compartments due to low retro-diffusion of the protonated molecule (ion trapping), with an ensuing vacuolar and autophagic cytopathology. In solid tissues, there is evidence that phagocytic cells, e.g., histiocytes, preferentially concentrate cationic drugs. We hypothesized that peripheral blood leukocytes could differentially take up a fluorescent model cation, quinacrine, depending on their phagocytic competence. Quinacrine transport parameters were determined in purified or total leukocyte suspensions at 37 °C. Purified polymorphonuclear leukocytes (PMNLs, essentially neutrophils) exhibited a quinacrine uptake velocity inferior to that of lymphocytes, but a consistently higher affinity (apparent K M 1.1 vs. 6.3 μM, respectively). However, the vacuolar (V)-ATPase inhibitor bafilomycin A1 prevented quinacrine transport or initiated its release in either cell type. PMNLs capture most of the quinacrine added at low concentrations to fresh peripheral blood leukocytes compared with lymphocytes and monocytes (cytofluorometry). Accumulation of the autophagy marker LC3-II occurred rapidly and at low drug concentrations in quinacrine-treated PMNLs (significant at ≥ 2.5 μM, ≥ 2 h). Lymphocytes contained more LAMP1 than PMNLs, suggesting that the mass of lysosomes and late endosomes is a determinant of quinacrine uptake V max . PMNLs, however, exhibited the highest capacity for pinocytosis (uptake of fluorescent dextran into endosomes). The selectivity of quinacrine distribution in peripheral blood leukocytes may be determined by the collaboration of a non-concentrating plasma membrane transport mechanism, tentatively identified as pinocytosis in PMNLs, with V-ATPase-mediated concentration. Intracellular reservoirs of cationic drugs are a potential source of toxicity (e.g., loss of lysosomal function in phagocytes). - Highlights: • Quinacrine is concentrated in acidic organelles via V-ATPase-mediated ion trapping

  2. Maternal chocolate and sucrose soft drink intake induces hepatic steatosis in rat offspring associated with altered lipid gene expression profile

    DEFF Research Database (Denmark)

    Kjærgaard, Maj; Nilsson, C.; Rosendal, A.

    2014-01-01

    weight gain and adiposity in offspring born to chow-fed dams. Conclusion: Our results suggest that supplementation of chocolate and soft drink during gestation and lactation contributes to early onset of hepatic steatosis associated with changes in hepatic gene expression and lipid handling....... until weaning, giving four dietary groups. Results: At postnatal day 1, offspring from high-fat/high-sucrose-fed dams were heavier and had increased hepatic triglycerides (TG), hepatic glycogen, blood glucose and plasma insulin compared with offspring from chow-fed dams. Hepatic genes involved in lipid...... oxidation, VLDL transport and insulin receptor were down-regulated, whereas FGF21 expression was up-regulated. Independent of postnatal litter size, offspring from high-fat/high-sucrose-fed dams aged 21 days had still increased hepatic TG and up-regulated FGF21 expression, while plasma insulin started...

  3. Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.

    Science.gov (United States)

    Durso, S C; Vieira, L M; Cruz, J N S; Azevedo, C S; Rodrigues, P H; Simionato, M R L

    2014-01-01

    Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

  4. Hijacking membrane transporters for arsenic phytoextraction

    Science.gov (United States)

    LeBlanc, Melissa S.; McKinney, Elizabeth C.; Meagher, Richard B.; Smith, Aaron P.

    2012-01-01

    Arsenic is a toxic metalloid and recognized carcinogen. Arsenate and arsenite are the most common arsenic species available for uptake by plants. As an inorganic phosphate (Pi) analog, arsenate is acquired by plant roots through endogenous Pi transport systems. Inside the cell, arsenate is reduced to the thiol-reactive form arsenite. Glutathione (GSH)-conjugates of arsenite may be extruded from the cell or sequestered in vacuoles by members of the ATP-binding cassette (ABC) family of transporters. In the present study we sought to enhance both plant arsenic uptake through Pi transporter overexpression, and plant arsenic tolerance through ABC transporter overexpression. We demonstrate that Arabidopsis thaliana plants overexpressing the high-affinity Pi transporter family members, AtPht1;1 or AtPht1;7, are hypersensitive to arsenate due to increased arsenate uptake. These plants do not exhibit increased sensitivity to arsenite. Co-overexpression of the yeast ABC transporter YCF1 in combination with AtPht1;1 or AtPht1;7 suppresses the arsenate-sensitive phenotype while further enhancing arsenic uptake. Taken together, our results support an arsenic transport mechanism in which arsenate uptake is increased through Pi transporter overexpression, and arsenic tolerance is enhanced through YCF1-mediated vacuolar sequestration. This work substantiates the viability of coupling enhanced uptake and vacuolar sequestration as a means for developing a prototypical engineered arsenic hyperaccumulator. PMID:23108027

  5. The Path of Carbon in Photosynthesis XIX. The Identification of Sucrose Phosphate in Sugar Beet Leaves

    Science.gov (United States)

    Buchanan, J. G.

    1952-09-01

    The recognition and characterization of a sucrose phosphate as an intermediate in sucrose by synthesis by green plants is described. A tentative structure for this phosphate is proposed and its mode of formation suggested.

  6. Genome-wide screen in Saccharomyces cerevisiae identifies vacuolar protein sorting, autophagy, biosynthetic, and tRNA methylation genes involved in life span regulation.

    Directory of Open Access Journals (Sweden)

    Paola Fabrizio

    2010-07-01

    Full Text Available The study of the chronological life span of Saccharomyces cerevisiae, which measures the survival of populations of non-dividing yeast, has resulted in the identification of homologous genes and pathways that promote aging in organisms ranging from yeast to mammals. Using a competitive genome-wide approach, we performed a screen of a complete set of approximately 4,800 viable deletion mutants to identify genes that either increase or decrease chronological life span. Half of the putative short-/long-lived mutants retested from the primary screen were confirmed, demonstrating the utility of our approach. Deletion of genes involved in vacuolar protein sorting, autophagy, and mitochondrial function shortened life span, confirming that respiration and degradation processes are essential for long-term survival. Among the genes whose deletion significantly extended life span are ACB1, CKA2, and TRM9, implicated in fatty acid transport and biosynthesis, cell signaling, and tRNA methylation, respectively. Deletion of these genes conferred heat-shock resistance, supporting the link between life span extension and cellular protection observed in several model organisms. The high degree of conservation of these novel yeast longevity determinants in other species raises the possibility that their role in senescence might be conserved.

  7. Genome-wide screen in Saccharomyces cerevisiae identifies vacuolar protein sorting, autophagy, biosynthetic, and tRNA methylation genes involved in life span regulation.

    Science.gov (United States)

    Fabrizio, Paola; Hoon, Shawn; Shamalnasab, Mehrnaz; Galbani, Abdulaye; Wei, Min; Giaever, Guri; Nislow, Corey; Longo, Valter D

    2010-07-15

    The study of the chronological life span of Saccharomyces cerevisiae, which measures the survival of populations of non-dividing yeast, has resulted in the identification of homologous genes and pathways that promote aging in organisms ranging from yeast to mammals. Using a competitive genome-wide approach, we performed a screen of a complete set of approximately 4,800 viable deletion mutants to identify genes that either increase or decrease chronological life span. Half of the putative short-/long-lived mutants retested from the primary screen were confirmed, demonstrating the utility of our approach. Deletion of genes involved in vacuolar protein sorting, autophagy, and mitochondrial function shortened life span, confirming that respiration and degradation processes are essential for long-term survival. Among the genes whose deletion significantly extended life span are ACB1, CKA2, and TRM9, implicated in fatty acid transport and biosynthesis, cell signaling, and tRNA methylation, respectively. Deletion of these genes conferred heat-shock resistance, supporting the link between life span extension and cellular protection observed in several model organisms. The high degree of conservation of these novel yeast longevity determinants in other species raises the possibility that their role in senescence might be conserved.

  8. Co-overexpressing a Plasma Membrane and a Vacuolar Membrane Sodium/Proton Antiporter Significantly Improves Salt Tolerance in Transgenic Arabidopsis Plants

    Science.gov (United States)

    Pehlivan, Necla; Sun, Li; Jarrett, Philip; Yang, Xiaojie; Mishra, Neelam; Chen, Lin; Kadioglu, Asim; Shen, Guoxin; Zhang, Hong

    2016-01-01

    The Arabidopsis gene AtNHX1 encodes a vacuolar membrane-bound sodium/proton (Na+/H+) antiporter that transports Na+ into the vacuole and exports H+ into the cytoplasm. The Arabidopsis gene SOS1 encodes a plasma membrane-bound Na+/H+ antiporter that exports Na+ to the extracellular space and imports H+ into the plant cell. Plants rely on these enzymes either to keep Na+ out of the cell or to sequester Na+ into vacuoles to avoid the toxic level of Na+ in the cytoplasm. Overexpression of AtNHX1 or SOS1 could improve salt tolerance in transgenic plants, but the improved salt tolerance is limited. NaCl at concentration >200 mM would kill AtNHX1-overexpressing or SOS1-overexpressing plants. Here it is shown that co-overexpressing AtNHX1 and SOS1 could further improve salt tolerance in transgenic Arabidopsis plants, making transgenic Arabidopsis able to tolerate up to 250 mM NaCl treatment. Furthermore, co-overexpression of AtNHX1 and SOS1 could significantly reduce yield loss caused by the combined stresses of heat and salt, confirming the hypothesis that stacked overexpression of two genes could substantially improve tolerance against multiple stresses. This research serves as a proof of concept for improving salt tolerance in other plants including crops. PMID:26985021

  9. Regulated Assembly of Vacuolar ATPase Is Increased during Cluster Disruption-induced Maturation of Dendritic Cells through a Phosphatidylinositol 3-Kinase/mTOR-dependent Pathway*

    Science.gov (United States)

    Liberman, Rachel; Bond, Sarah; Shainheit, Mara G.; Stadecker, Miguel J.; Forgac, Michael

    2014-01-01

    The vacuolar (H+)-ATPases (V-ATPases) are ATP-driven proton pumps composed of a peripheral V1 domain and a membrane-embedded V0 domain. Regulated assembly of V1 and V0 represents an important regulatory mechanism for controlling V-ATPase activity in vivo. Previous work has shown that V-ATPase assembly increases during maturation of bone marrow-derived dendritic cells induced by activation of Toll-like receptors. This increased assembly is essential for antigen processing, which is dependent upon an acidic lysosomal pH. Cluster disruption of dendritic cells induces a semi-mature phenotype associated with immune tolerance. Thus, semi-mature dendritic cells are able to process and present self-peptides to suppress autoimmune responses. We have investigated V-ATPase assembly in bone marrow-derived, murine dendritic cells and observed an increase in assembly following cluster disruption. This increased assembly is not dependent upon new protein synthesis and is associated with an increase in concanamycin A-sensitive proton transport in FITC-loaded lysosomes. Inhibition of phosphatidylinositol 3-kinase with wortmannin or mTORC1 with rapamycin effectively inhibits the increased assembly observed upon cluster disruption. These results suggest that the phosphatidylinositol 3-kinase/mTOR pathway is involved in controlling V-ATPase assembly during dendritic cell maturation. PMID:24273170

  10. Co-overexpressing a Plasma Membrane and a Vacuolar Membrane Sodium/Proton Antiporter Significantly Improves Salt Tolerance in Transgenic Arabidopsis Plants.

    Science.gov (United States)

    Pehlivan, Necla; Sun, Li; Jarrett, Philip; Yang, Xiaojie; Mishra, Neelam; Chen, Lin; Kadioglu, Asim; Shen, Guoxin; Zhang, Hong

    2016-05-01

    The Arabidopsis gene AtNHX1 encodes a vacuolar membrane-bound sodium/proton (Na(+)/H(+)) antiporter that transports Na(+) into the vacuole and exports H(+) into the cytoplasm. The Arabidopsis gene SOS1 encodes a plasma membrane-bound Na(+)/H(+) antiporter that exports Na(+) to the extracellular space and imports H(+) into the plant cell. Plants rely on these enzymes either to keep Na(+) out of the cell or to sequester Na(+) into vacuoles to avoid the toxic level of Na(+) in the cytoplasm. Overexpression of AtNHX1 or SOS1 could improve salt tolerance in transgenic plants, but the improved salt tolerance is limited. NaCl at concentration >200 mM would kill AtNHX1-overexpressing or SOS1-overexpressing plants. Here it is shown that co-overexpressing AtNHX1 and SOS1 could further improve salt tolerance in transgenic Arabidopsis plants, making transgenic Arabidopsis able to tolerate up to 250 mM NaCl treatment. Furthermore, co-overexpression of AtNHX1 and SOS1 could significantly reduce yield loss caused by the combined stresses of heat and salt, confirming the hypothesis that stacked overexpression of two genes could substantially improve tolerance against multiple stresses. This research serves as a proof of concept for improving salt tolerance in other plants including crops. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  11. Single, but not multiple pairings of sucrose and corticosterone enhance memory for sucrose drinking and amplify remote reward relativity effects

    NARCIS (Netherlands)

    Pecoraro, Norman; Gomez, Francisca; La Fleur, Susanne; Roy, Monica; Dallman, Mary F.

    2005-01-01

    This study tested whether pre-training pairings of ingestion of a 32% sucrose solution and injection(s) of corticosterone (B) would enhance later ingestion in the absence of B, and whether these effects would carry over into later contrast-like effects when animals were subsequently shifted to 4%

  12. Choline but not its derivative betaine blocks slow vacuolar channels in the halophyte Chenopodium quinoa: implications for salinity stress responses.

    Science.gov (United States)

    Pottosin, Igor; Bonales-Alatorre, Edgar; Shabala, Sergey

    2014-11-03

    Activity of tonoplast slow vacuolar (SV, or TPC1) channels has to be under a tight control, to avoid undesirable leak of cations stored in the vacuole. This is particularly important for salt-grown plants, to ensure efficient vacuolar Na(+) sequestration. In this study we show that choline, a cationic precursor of glycine betaine, efficiently blocks SV channels in leaf and root vacuoles of the two chenopods, Chenopodium quinoa (halophyte) and Beta vulgaris (glycophyte). At the same time, betaine and proline, two major cytosolic organic osmolytes, have no significant effect on SV channel activity. Physiological implications of these findings are discussed. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  13. Osmotic distillation and quality evaluation of sucrose, apple and orange juices in hollow fiber membrane contactor

    Directory of Open Access Journals (Sweden)

    Rehman Waheed Ur

    2017-01-01

    Full Text Available Sucrose solution, apple and orange juices were concentrated through osmotic distillation (OD process using a mini-module Liqui-CelTM hollow fibre membrane contactor. Mass transport characteristics of water molecules from feed to stripping solution were studied. Process parameters such as feed temperature, feed flow rate and concentration of stripping solution (CaCl2 were varied. Sucrose solution was concentrated from 135 to 510 g TSS kg-1 in 340 min using feed-in- -lumen flow configuration at a start-up water flux of 0.250 L m-2 h-1 and a temperature of 30°C. Similarly, it was concentrated up to 510 g TSS kg-1 in 200 min using feed-in-shell flow configuration at a start-up water flux of 0.505 L m-2 hr1 and a temperature of 30°C. In a total recycle time of 340 min, clarified apple and orange juices were concentrated up to 500 g TSS kg-1 using feed-in-lumen flow configuration at a start-up water flux of 0.204 and 0.294 L m-2 hr1, respectively. It was found that quality parameters of fruit juices were well improved after the osmotic distillation process. The process therefore has good potential for application in the fruit processing industry for concentration of fruit juices.

  14. Process control of an ethanol fermentation with an enzyme thermistor as a sucrose sensor

    Energy Technology Data Exchange (ETDEWEB)

    Mandenius, C F; Danielsson, B; Mattiasson, B

    1981-01-01

    An enzyme thermistor was used to monitor and control the sucrose concentration in a conversion of sucrose to EtOH with immobilized yeast. A continuous stirred tank reactor containing Ca alginate-immobilized Saccharomyces cerevisiae was used. The enzyme thermistor continuously measured the sucrose concentration in the fermentor with an online arrangement giving stable and reproducible heat signals. The control of the sucrose concentration level was performed with an analog P1-controller.

  15. Schisandrin B protects PC12 cells by decreasing the expression of amyloid precursor protein and vacuolar protein sorting 35★

    Science.gov (United States)

    Yan, Mingmin; Mao, Shanping; Dong, Huimin; Liu, Baohui; Zhang, Qian; Pan, Gaofeng; Fu, Zhiping

    2012-01-01

    PC12 cell injury was induced using 20 μM amyloid β-protein 25–35 to establish a model of Alzheimer's disease. The cells were then treated with 5, 10, and 25 μM Schisandrin B. Methylthiazolyldiphenyl-tetrazolium bromide assays and Hoechst 33342 staining results showed that with increasing Schisandrin B concentration, the survival rate of PC12 cells injured by amyloid β-protein 25–35 gradually increased and the rate of apoptosis gradually decreased. Reverse transcription-PCR, immunocytochemical staining and western blot results showed that with increasing Schisandrin B concentration, the mRNA and protein expression of vacuolar protein sorting 35 and amyloid precursor protein were gradually decreased. Vacuolar protein sorting 35 and amyloid precursor protein showed a consistent trend for change. These findings suggest that 5, 10, and 25 μM Schisandrin B antagonizes the cellular injury induced by amyloid β-protein 25–35 in a dose-dependent manner. This may be caused by decreasing the expression of vacuolar protein sorting 35 and amyloid precursor protein. PMID:25745458

  16. Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H+ -pumping pyrophosphatase in pepper plants.

    Science.gov (United States)

    Vigani, Gianpiero; Rolli, Eleonora; Marasco, Ramona; Dell'Orto, Marta; Michoud, Grégoire; Soussi, Asma; Raddadi, Noura; Borin, Sara; Sorlini, Claudia; Zocchi, Graziano; Daffonchio, Daniele

    2018-05-22

    It has been previously shown that the transgenic overexpression of the plant root vacuolar proton pumps H + -ATPase (V-ATPase) and H + -PPase (V-PPase) confer tolerance to drought. Since plant-root endophytic bacteria can also promote drought tolerance, we hypothesize that such promotion can be associated to the enhancement of the host vacuolar proton pumps expression and activity. To test this hypothesis, we selected two endophytic bacteria endowed with an array of in vitro plant growth promoting traits. Their genome sequences confirmed the presence of traits previously shown to confer drought resistance to plants, such as the synthesis of nitric oxide and of organic volatile organic compounds. We used the two strains on pepper (Capsicuum annuum L.) because of its high sensitivity to drought. Under drought conditions, both strains stimulated a larger root system and enhanced the leaves' photosynthetic activity. By testing the expression and activity of the vacuolar proton pumps, H + -ATPase (V-ATPase) and H + -PPase (V-PPase), we found that bacterial colonization enhanced V-PPase only. We conclude that the enhanced expression and activity of V-PPase can be favoured by the colonization of drought-tolerance-inducing bacterial endophytes. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia

    Science.gov (United States)

    Belke, Terry W.; Duncan, Ian D.; Pierce, W. David

    2006-01-01

    Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior…

  18. Turgor-mediated transport of sugars

    International Nuclear Information System (INIS)

    Daie, J.

    1986-01-01

    Membrane associated processes have been suggested to be modulated by cellular turgor. The nature of this regulation is not, however, clearly understood. Evidence is presented that active but not passive transport of sugars is turgor regulated. Isolated phloem tissue, vascular bundles or storage parenchyma of celery were incubated in buffered solutions adjusted to 100, 200 or 400 m osmolal that contained various concentrations of 14 C-sugars. Cellular turgor was manipulated by using the non-permeating PEG (3350). Saturating carrier-mediated sucrose transport which is present only in phloem-containing tissue was enhanced under low turgor conditions. Sucrose diffusion, the predominant mode of uptake in non-phloem parenchyma tissue was not affected by cellular turgor. Furthermore, GA and IAA seem to interact with cellular turgor to bring about modified rates of sucrose uptake. The data are consistent with observations that sucrose loading is enhanced under mild water deficit conditions

  19. Analysis of Nanobody-Epitope Interactions in Living Cells via Quantitative Protein Transport Assays.

    Science.gov (United States)

    Früholz, Simone; Pimpl, Peter

    2017-01-01

    Over the past few decades, quantitative protein transport analyses have been used to elucidate the sorting and transport of proteins in the endomembrane system of plants. Here, we have applied our knowledge about transport routes and the corresponding sorting signals to establish an in vivo system for testing specific interactions between soluble proteins.Here, we describe the use of quantitative protein transport assays in tobacco mesophyll protoplasts to test for interactions occurring between a GFP-binding nanobody and its GFP epitope. For this, we use a secreted GFP-tagged α-amylase as a reporter together with a vacuolar-targeted RFP-tagged nanobody. The interaction between these proteins is then revealed by a transport alteration of the secretory reporter due to the interaction-triggered attachment of the vacuolar sorting signal.

  20. Vacuolar and cytoskeletal dynamics during elicitor-induced programmed cell death in tobacco BY-2 cells.

    Science.gov (United States)

    Higaki, Takumi; Kadota, Yasuhiro; Goh, Tatsuaki; Hayashi, Teruyuki; Kutsuna, Natsumaro; Sano, Toshio; Hasezawa, Seiichiro; Kuchitsu, Kazuyuki

    2008-09-01

    Responses of plant cells to environmental stresses often involve morphological changes, differentiation and redistribution of various organelles and cytoskeletal network. Tobacco BY-2 cells provide excellent model system for in vivo imaging of these intracellular events. Treatment of the cell cycle-synchronized BY-2 cells with a proteinaceous oomycete elicitor, cryptogein, induces highly synchronous programmed cell death (PCD) and provide a model system to characterize vacuolar and cytoskeletal dynamics during the PCD. Sequential observation revealed dynamic reorganization of the vacuole and actin microfilaments during the execution of the PCD. We further characterized the effects cryptogein on mitotic microtubule organization in cell cycle-synchronized cells. Cryptogein treatment at S phase inhibited formation of the preprophase band, a cortical microtubule band that predicts the cell division site. Cortical microtubules kept their random orientation till their disruption that gradually occurred during the execution of the PCD twelve hours after the cryptogein treatment. Possible molecular mechanisms and physiological roles of the dynamic behavior of the organelles and cytoskeletal network in the pathogenic signal-induced PCD are discussed.

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

    Science.gov (United States)

    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.

  2. Regulation of vacuolar H{sup +}-ATPase in microglia by RANKL

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Eric M.; Ricofort, Ryan D.; Zuo, Jian [Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL 32610 (United States); Ochotny, Noelle [Department of Pharmacology, University of Toronto, Toronto, Ont., Canada M5G 1G6 (Canada); Manolson, Morris F. [Faculty of Dentistry, University of Toronto, Toronto, Ont., Canada M5G 1G6 (Canada); Holliday, L. Shannon, E-mail: sholliday@dental.ufl.edu [Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL 32610 (United States); Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL 32610 (United States)

    2009-11-06

    Vacuolar H{sup +}-ATPases (V-ATPases) are large electrogenic proton pumps composed of numerous subunits that play vital housekeeping roles in the acidification of compartments of the endocytic pathway. Additionally, V-ATPases play specialized roles in certain cell types, a capacity that is linked to cell type selective expression of isoforms of some of the subunits. We detected low levels of the a3 isoform of the a-subunit in mouse brain extracts. Examination of various brain-derived cell types by immunoblotting showed a3 was expressed in the N9 microglia cell line and in primary microglia, but not in other cell types. The expression of a3 in osteoclasts requires stimulation by Receptor Activator of Nuclear Factor {kappa}B-ligand (RANKL). We found that Receptor Activator of Nuclear Factor {kappa}B (RANK) was expressed by microglia. Stimulation of microglia with RANKL triggered increased expression of a3. V-ATPases in microglia were shown to bind microfilaments, and stimulation with RANKL increased the proportion of V-ATPase associated with the detergent-insoluble cytoskeletal fraction and with actin. In summary, microglia express the a3-subunit of V-ATPase. The expression of a3 and the interaction between V-ATPases and microfilaments was modulated by RANKL. These data suggest a novel molecular pathway for regulating microglia.

  3. Cryo-EM studies of the structure and dynamics of vacuolar-type ATPases

    Science.gov (United States)

    Mazhab-Jafari, Mohammad T.; Rubinstein, John L.

    2016-01-01

    Electron cryomicroscopy (cryo-EM) has significantly advanced our understanding of molecular structure in biology. Recent innovations in both hardware and software have made cryo-EM a viable alternative for targets that are not amenable to x-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Cryo-EM has even become the method of choice in some situations where x-ray crystallography and NMR spectroscopy are possible but where cryo-EM can determine structures at higher resolution or with less time or effort. Rotary adenosine triphosphatases (ATPases) are crucial to the maintenance of cellular homeostasis. These enzymes couple the synthesis or hydrolysis of adenosine triphosphate to the use or production of a transmembrane electrochemical ion gradient, respectively. However, the membrane-embedded nature and conformational heterogeneity of intact rotary ATPases have prevented their high-resolution structural analysis to date. Recent application of cryo-EM methods to the different types of rotary ATPase has led to sudden advances in understanding the structure and function of these enzymes, revealing significant conformational heterogeneity and characteristic transmembrane α helices that are highly tilted with respect to the membrane. In this Review, we will discuss what has been learned recently about rotary ATPase structure and function, with a particular focus on the vacuolar-type ATPases. PMID:27532044

  4. Vacuolar processing enzyme plays an essential role in the crystalline structure of glutelin in rice seed.

    Science.gov (United States)

    Kumamaru, Toshihiro; Uemura, Yuji; Inoue, Yoshimi; Takemoto, Yoko; Siddiqui, Sadar Uddin; Ogawa, Masahiro; Hara-Nishimura, Ikuko; Satoh, Hikaru

    2010-01-01

    To identify the function of genes that regulate the processing of proglutelin, we performed an analysis of glup3 mutants, which accumulates excess amounts of proglutelin and lack the vacuolar processing enzyme (VPE). VPE activity in developing seeds from glup3 lines was reduced remarkably compared with the wild type. DNA sequencing of the VPE gene in glup3 mutants revealed either amino acid substitutions or the appearance of a stop codon within the coding region. Microscopic observations showed that alpha-globulin and proglutelin were distributed homogeneously within glup3 protein storage vacuoles (PSVs), and that glup3 PSVs lacked the crystalline lattice structure typical of wild-type PSVs. This suggests that the processing of proglutelin by VPE in rice is essential for proper PSV structure and compartmentalization of storage proteins. Growth retardation in glup3 seedlings was also observed, indicating that the processing of proglutelin influences early seedling development. These findings indicate that storage of glutelin in its mature form as a crystalline structure in PSVs is required for the rapid use of glutelin as a source of amino acids during early seedling development. In conclusion, VPE plays an important role in the formation of protein crystalline structures in PSVs.

  5. Sucrose synthase: A unique glycosyltransferase for biocatalytic glycosylation process development.

    Science.gov (United States)

    Schmölzer, Katharina; Gutmann, Alexander; Diricks, Margo; Desmet, Tom; Nidetzky, Bernd

    2016-01-01

    Sucrose synthase (SuSy, EC 2.4.1.13) is a glycosyltransferase (GT) long known from plants and more recently discovered in bacteria. The enzyme catalyzes the reversible transfer of a glucosyl moiety between fructose and a nucleoside diphosphate (NDP) (sucrose+NDP↔NDP-glucose+fructose). The equilibrium for sucrose conversion is pH dependent, and pH values between 5.5 and 7.5 promote NDP-glucose formation. The conversion of a bulk chemical to high-priced NDP-glucose in a one-step reaction provides the key aspect for industrial interest. NDP-sugars are important as such and as key intermediates for glycosylation reactions by highly selective Leloir GTs. SuSy has gained renewed interest as industrially attractive biocatalyst, due to substantial scientific progresses achieved in the last few years. These include biochemical characterization of bacterial SuSys, overproduction of recombinant SuSys, structural information useful for design of tailor-made catalysts, and development of one-pot SuSy-GT cascade reactions for production of several relevant glycosides. These advances could pave the way for the application of Leloir GTs to be used in cost-effective processes. This review provides a framework for application requirements, focusing on catalytic properties, heterologous enzyme production and reaction engineering. The potential of SuSy biocatalysis will be presented based on various biotechnological applications: NDP-sugar synthesis; sucrose analog synthesis; glycoside synthesis by SuSy-GT cascade reactions. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Alveolar wound healing in rats fed on high sucrose diet.

    Science.gov (United States)

    Baró, María A; Rocamundi, Marina R; Viotto, Javier O; Ferreyra, Ruth S

    2013-01-01

    The potential for bone repair is influenced by various biochemical, biomechanical, hormonal, and pathological mechanisms and factors such as diet and its components, all of which govern the behavior and function of the cells responsible for forming new bone. Several authors suggest that a high sucrose diet could change the calcium balance and bone composition in animals, altering hard tissue mineralization. The mechanism by which it occurs is unclear. Alveolar healing following tooth extraction has certain characteristics making this type of wound unique, in both animals and humans. The general aim of this study was to evaluate and quantify the biological response during alveolar healing following tooth extraction in rats fed on high sucrose diets, by means of osteocyte lacunae histomorphometry, counting empty lacunae and measuring areas of bone quiescence, formation and resorption. Forty-two Wistar rats of both sexes were divided into two groups: an experimental group fed on modified Stephan Harris diet (43% sucrose) and a control group fed on standard balanced diet. The animals were anesthetized and their left and right lower molars extracted. They were killed at 0 hours, 14, 28, 60 and 120 days. Samples were fixed, decalcified in EDTA and embedded in paraffin to prepare sections for optical microscopy which were stained with hematoxylin/eosin. Histomorphometric analysis showed significant differences in the size of osteocyte lacunae between groups at 28 and 60 days, with the experimental group having larger lacunae. There were more empty lacunae in the experimental group at 14 days, and no significant difference in the areas of bone activity. A high sucrose diet could modify the morphology and quality of bone tissue formed in the alveolus following tooth extraction.

  7. Sucrose polyesters from poultry fat as non-ionic emulsifiers

    Directory of Open Access Journals (Sweden)

    Megahed, Mohamed G.

    2000-12-01

    Full Text Available Poultry fats are rich in palmitic and oleic acids are produced as by-products from poultry industries. These fats can be utilized in the preparation of emulsifiers. Sucrose esters of poultry fat are prepared from low-cost poultry fat and sucrose by esterification. The yield of sucrose esters prepared in this work exceeds than 85%. The hydrophilic-lipophilic balance (HLB, surface tension, interfacial tension and stability index (SI were evaluated and compared with standard emulsifiers prepared from pure palmitate and oleate esters. Concerning the stability of emulsions, the values of interfacial tension and HLB were higher for the sucrose esters of poultry fat.Las grasas de aves de corral son ricas en ácidos palmítico y oleico y son producidas como subproductos de las industrias avícolas. Estas grasas pueden ser utilizadas en la preparación de emulsionantes. Los ésteres de sacarosa de grasas de aves de corral fueron preparadas a partir de grasas de bajo coste y sacarosa por esterificación. El rendimiento de los ésteres de sacarosa preparados en este trabajo superó el 85%. El balance hidrofílicolipofílico (HLB, tensión superficial, tensión interfacial e índice de estabilidad (SI fueron evaluados y comparados con emulsionantes estandar preparados de ésteres de palmitato y oleato puros. Los valores de tensión interfacial y el HLB fueron más altos en los poliésteres de sacarosa de las grasas de aves de corral.

  8. Structural analyses of sucrose laurate regioisomers by mass spectrometry techniques

    DEFF Research Database (Denmark)

    Lie, Aleksander; Stensballe, Allan; Pedersen, Lars Haastrup

    2015-01-01

    6- And 6′-O-lauroyl sucrose were isolated and analyzed by matrix-assisted laser desorption/ionisation (MALDI) time-of-flight (TOF) mass spectrometry (MS), Orbitrap high-resolution (HR) MS, and electrospray-ionization (ESI) tandem mass spectrometry (MS/MS). The analyses aimed to explore the physic......6- And 6′-O-lauroyl sucrose were isolated and analyzed by matrix-assisted laser desorption/ionisation (MALDI) time-of-flight (TOF) mass spectrometry (MS), Orbitrap high-resolution (HR) MS, and electrospray-ionization (ESI) tandem mass spectrometry (MS/MS). The analyses aimed to explore.......8, respectively, and Orbitrap HRMS confirmed the mass of [M+Na]+ (m/z 547.2712). ESI-MS/MS on the precursor ion [M+Na]+ resulted in product ion mass spectra showing two high-intensity signals for each sample. 6-O-Lauroyl sucrose produced signals located at m/z 547.27 and m/z 385.21, corresponding to the 6-O...

  9. Effect of heavy ion irradiation on sucrose radical production

    International Nuclear Information System (INIS)

    Nakagawa, Kouichi; Sato, Yukio

    2004-01-01

    We investigated sucrose radicals produced by heavy-ion irradiation with various LETs (linear energy transfer) and the possibility for a sucrose ESR (electron spin resonance) dosimeter. The obtained spectral pattern was the same as that for helium (He) ions, carbon (C) ions, neon (Ne) ions, argon (Ar) ions, and iron (Fe) ions. Identical spectra were measured after one year, but the initial intensities decreased by a few percent when the samples were kept in ESR tubes with the caps at ambient temperature. The total spin concentration obtained by heavy-ion irradiation had a linear relation with the absorbed dose, and correlated logarithmically with the LET. Qualitative ESR analyses showed that the production of sucrose radicals depended on both the particle identity and the LET at the same dose. The production of spin concentration by He ions was the most sensitive to LET. Empirical relations between the LET and the spin yield for various particles imply that the LET at a certain dose can be estimated by the spin concentration. (authors)

  10. Photocatalytic properties of hierarchical ZnO flowers synthesized by a sucrose-assisted hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Lv Wei [Key Laboratory of Photonic and Electric Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Wei Bo [Center for Condensed Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Xu Lingling, E-mail: xulingling_hit@163.com [Key Laboratory of Photonic and Electric Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China) and Center for Condensed Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Zhao Yan, E-mail: zhaoyan516@126.com [Department of Physics, Northeast Forestry University, Harbin 150040 (China); Gao Hong; Liu Jia [Key Laboratory of Photonic and Electric Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Hierarchical ZnO flowers were synthesized via a sucrose-assisted urea hydrothermal method. Black-Right-Pointing-Pointer The sucrose added ZnO flowers showed improved activity mainly due to the improved crystallinity. Black-Right-Pointing-Pointer The effect of sucrose content was studied and optimized. - Abstract: In this work, hierarchical ZnO flowers were synthesized via a sucrose-assisted urea hydrothermal method. The thermogravimetric analysis/differential thermal analysis (TGA-DTA) and Fourier transform infrared spectra (FTIR) showed that sucrose acted as a complexing agent in the synthesis process and assisted combustion during annealing. Photocatalytic activity was evaluated using the degradation of organic dye methyl orange. The sucrose added ZnO flowers showed improved activity, which was mainly attributed to the better crystallinity as confirmed by X-ray photoelectron spectroscopy (XPS) analysis. The effect of sucrose amount on photocatalytic activity was also studied.

  11. The genes and enzymes of sucrose metabolism in moderately thermophilic methanotroph Methylocaldum szegediense O12.

    Science.gov (United States)

    But, Sergey Y; Solntseva, Natalia P; Egorova, Svetlana V; Mustakhimov, Ildar I; Khmelenina, Valentina N; Reshetnikov, Alexander; Trotsenko, Yuri A

    2018-05-01

    Four enzymes involved in sucrose metabolism: sucrose phosphate synthase (Sps), sucrose phosphate phosphatase (Spp), sucrose synthase (Sus) and fructokinase (FruK), were obtained as his-tagged proteins from the moderately thermophilic methanotroph Methylocaldum szegediense O12. Sps, Spp, FruK and Sus demonstrated biochemical properties similar to those of other bacterial counterparts, but the translated amino acid sequences of Sps and Spp displayed high divergence from the respective microbial enzymes. The Sus of M. szegediense O12 catalyzed the reversible reaction of sucrose cleavage in the presence of ADP or UDP and preferred ADP as a substrate, thus implying a connection between sucrose and glycogen metabolism. Sus-like genes were found only in a few methanotrophs, whereas amylosucrase was generally used in sucrose cleavage in this group of bacteria. Like other microbial fructokinases, FruK of M. szegediense O12 showed a high specificity to fructose.

  12. Structures and immunolocalization of Na+, K+ -ATPase, Na+ /H+ exchanger 3 and vacuolar-type H+ -ATPase in the gills of blennies (Teleostei: Blenniidae) inhabiting rocky intertidal areas.

    Science.gov (United States)

    Uchiyama, M; Komiyama, M; Yoshizawa, H; Shimizu, N; Konno, N; Matsuda, K

    2012-05-01

    The structure and immunolocalization of the ion transporters Na(+) ,K(+) -ATPase (NKA), Na(+) /H(+) exchanger (NHE3) and vacuolar-type H(+) -ATPase (VHA) were examined in the gills of teleosts of the family Blenniidae, which inhabit rocky shores with vertical zonation in subtropical seas. These features were compared among the following species with different ecologies: the amphibious rockskipper blenny Andamia tetradactylus, the intertidal white-finned blenny Praealticus tanegasimae and the purely marine yaeyama blenny Ecsenius yaeyamaensis. Light and electron microscopic observations indicated that thick gill filaments were arranged close to each other and alternately on two hemibranches of a gill arch in the opercular space of A. tetradactylus. Many mucous cells (MC) and mitochondrion-rich cells (MRC) were present in the interlamellar regions of the gill filament. An immunohistochemical study demonstrated that numerous NKA, NHE3 and some VHA were located predominantly on presumed MRCs of gill filaments and at the base of the lamellae. Analyses using serial (mirror image) sections of the gills indicated that only a few NKA immunoreactive cells (IRC) were colocalized with VHA on some MRCs in the filaments. In the gills of P. tanegasimae, NKA- and NHE3-IRCs were observed in the interlamellar region of the filaments and at the base of the lamellae. VHA-IRCs were located sparsely on the lamellae and filaments. In the gills of E. yaeyamaensis, the lamellae and filaments were thin and straight, respectively. MCs were located at the tip as well as found scattered in the interlamellar region of gill filaments. NKA-, NHE3- and VHA-IRCs were moderately frequently observed in the filaments and rarely on the lamellae. This study shows that the structure and distribution of ion transporters in the gills differ among the three blennid species, presumably reflecting their different ecologies. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the

  13. Impact of AtNHX1, a vacuolar Na+/H+ antiporter, upon gene expression during short- and long-term salt stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Blumwald Eduardo

    2007-04-01

    Full Text Available Abstract Background AtNHX1, the most abundant vacuolar Na+/H+ antiporter in Arabidopsis thaliana, mediates the transport of Na+ and K+ into the vacuole, influencing plant development and contributing to salt tolerance. In this report, microarray expression profiles of wild type plants, a T-DNA insertion knockout mutant of AtNHX1 (nhx1, and a 'rescued' line (NHX1::nhx1 were exposed to both short (12 h and 48 h and long (one and two weeks durations of a non-lethal salt stress to identify key gene transcripts associated with the salt response that are influenced by AtNHX1. Results 147 transcripts showed both salt responsiveness and a significant influence of AtNHX1. Fifty-seven of these genes showed an influence of the antiporter across all salt treatments, while the remaining genes were influenced as a result of a particular duration of salt stress. Most (69% of the genes were up-regulated in the absence of AtNHX1, with the exception of transcripts encoding proteins involved with metabolic and energy processes that were mostly down-regulated. Conclusion While part of the AtNHX1-influenced transcripts were unclassified, other transcripts with known or putative roles showed the importance of AtNHX1 to key cellular processes that were not necessarily limited to the salt stress response; namely calcium signaling, sulfur metabolism, cell structure and cell growth, as well as vesicular trafficking and protein processing. Only a small number of other salt-responsive membrane transporter transcripts appeared significantly influenced by AtNHX1.

  14. Anti-obesity effect of Lactobacillus gasseri BNR17 in high-sucrose diet-induced obese mice.

    Directory of Open Access Journals (Sweden)

    Ji-Hee Kang

    Full Text Available Previously, we reported that Lactobacillus gasseri BNR17 (BNR17, a probiotic strain isolated from human breast milk, inhibited increases in body weight and adipocyte tissue weight in high-sucrose diet-fed Sprague-Dawley (SD rats and reduced glucose levels in type 2 diabetes mice. In the current study, we conducted further experiments to extend these observations and elucidate the mechanism involved. C57BL/6J mice received a normal diet, high-sucrose diet or high-sucrose diet containing L. gasseri BNR17 (10(9 or 10(10 CFU for 10 weeks. The administration of L. gasseri BNR17 significantly reduced the body weight and white adipose tissue weight regardless of the dose administered. In BNR17-fed groups, mRNA levels of fatty acid oxidation-related genes (ACO, CPT1, PPARα, PPARδ were significantly higher and those of fatty acid synthesis-related genes (SREBP-1c, ACC were lower compared to the high-sucrose-diet group. The expression of GLUT4, main glucose transporter-4, was elevated in BNR17-fed groups. L. gasseri BNR17 also reduced the levels of leptin and insulin in serum. These results suggest that the anti-obesity actions of L. gasseri BNR17 can be attributed to elevated expression of fatty acid oxidation-related genes and reduced levels of leptin. Additionally, data suggested the anti-diabetes activity of L. gasseri BNR17 may be to due elevated GLUT4 and reduced insulin levels.

  15. Evaluation of [14C] and [13C]Sucrose as Blood-Brain Barrier Permeability Markers.

    Science.gov (United States)

    Miah, Mohammad K; Chowdhury, Ekram A; Bickel, Ulrich; Mehvar, Reza

    2017-06-01

    Nonspecific quantitation of [ 14 C]sucrose in blood and brain has been routinely used as a quantitative measure of the in vivo blood-brain barrier (BBB) integrity. However, the reported apparent brain uptake clearance (K in ) of the marker varies widely (∼100-fold). We investigated the accuracy of the use of the marker in comparison with a stable isotope of sucrose ([ 13 C]sucrose) measured by a specific liquid chromatography-tandem mass spectrometry method. Rats received single doses of each marker, and the K in values were determined. Surprisingly, the K in value of [ 13 C]sucrose was 6- to 7-fold lower than that of [ 14 C]sucrose. Chromatographic fractionation after in vivo administration of [ 14 C]sucrose indicated that the majority of the brain content of radioactivity belonged to compounds other than the intact [ 14 C]sucrose. However, mechanistic studies failed to reveal any substantial metabolism of the marker. The octanol:water partition coefficient of [ 14 C]sucrose was >2-fold higher than that of [ 13 C]sucrose, indicating the presence of lipid-soluble impurities in the [ 14 C]sucrose solution. Our data indicate that [ 14 C]sucrose overestimates the true BBB permeability to sucrose. We suggest that specific quantitation of the stable isotope ( 13 C) of sucrose is a more accurate alternative to the current widespread use of the radioactive sucrose as a BBB marker. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  16. Ion transporters involved in acidification of the resorption lacuna in osteoclasts

    DEFF Research Database (Denmark)

    Henriksen, K.; Sorensen, M.G.; Jensen, V.K.

    2008-01-01

    Osteoclasts possess a large amount of ion transporters, which participate in bone resorption; of these, the vacuolar-adenosine trisphosphatase (V-ATPase) and the chloride-proton antiporter ClC-7 acidify the resorption lacuna. However, whether other ion transporters participate in this process is ......, including carbonic anhydrase II, the NHEs, and potassium-chloride cotransporters, are all involved in resorption but do not seem to directly be involved in acidification of the lysosomes Udgivelsesdato: 2008/9......Osteoclasts possess a large amount of ion transporters, which participate in bone resorption; of these, the vacuolar-adenosine trisphosphatase (V-ATPase) and the chloride-proton antiporter ClC-7 acidify the resorption lacuna. However, whether other ion transporters participate in this process...

  17. Identification of a new target of miR-16, Vacuolar Protein Sorting 4a.

    Directory of Open Access Journals (Sweden)

    Neeta Adhikari

    Full Text Available The rationale was to utilize a bioinformatics approach to identify miRNA binding sites in genes with single nucleotide mutations (SNPs to discover pathways in heart failure (HF.The objective was to focus on the genes containing miRNA binding sites with miRNAs that were significantly altered in end-stage HF and in response to a left ventricular assist device (LVAD.BEDTools v2.14.3 was used to discriminate SNPs within predicted 3'UTR miRNA binding sites. A member of the miR-15/107 family, miR-16, was decreased in the circulation of end-stage HF patients and increased in response to a LVAD (p<0.001. MiR-16 decreased Vacuolar Protein Sorting 4a (VPS4a expression in HEK 293T cells (p<0.01. The SNP rs16958754 was identified in the miR-15/107 family binding site of VPS4a which abolished direct binding of miR-16 to the 3'UTR of VPS4a (p<0.05. VPS4a was increased in the circulation of end-stage HF patients (p<0.001, and led to a decrease in the number of HEK 293T cells in vitro (p<0.001.We provide evidence that miR-16 decreases in the circulation of end-stage HF patients and increases with a LVAD. Modeling studies suggest that miR-16 binds to and decreases expression of VPS4a. Overexpression of VPS4a decreases cell number. Together, these experiments suggest that miR-16 and VPS4a expression are altered in end-stage HF and in response to unloading with a LVAD. This signaling pathway may lead to reduced circulating cell number in HF.

  18. Functionally Similar WRKY Proteins Regulate Vacuolar Acidification in Petunia and Hair Development in Arabidopsis.

    Science.gov (United States)

    Verweij, Walter; Spelt, Cornelis E; Bliek, Mattijs; de Vries, Michel; Wit, Niek; Faraco, Marianna; Koes, Ronald; Quattrocchio, Francesca M

    2016-03-01

    The WD40 proteins ANTHOCYANIN11 (AN11) from petunia (Petunia hybrida) and TRANSPARENT TESTA GLABRA1 (TTG1) from Arabidopsis thaliana and associated basic helix-loop-helix (bHLH) and MYB transcription factors activate a variety of differentiation processes. In petunia petals, AN11 and the bHLH protein AN1 activate, together with the MYB protein AN2, anthocyanin biosynthesis and, together with the MYB protein PH4, distinct genes, such as PH1 and PH5, that acidify the vacuole. To understand how AN1 and AN11 activate anthocyanin biosynthetic and PH genes independently, we isolated PH3. We found that PH3 is a target gene of the AN11-AN1-PH4 complex and encodes a WRKY protein that can bind to AN11 and is required, in a feed-forward loop, together with AN11-AN1-PH4 for transcription of PH5. PH3 is highly similar to TTG2, which regulates hair development, tannin accumulation, and mucilage production in Arabidopsis. Like PH3, TTG2 can bind to petunia AN11 and the Arabidopsis homolog TTG1, complement ph3 in petunia, and reactivate the PH3 target gene PH5. Our findings show that the specificity of WD40-bHLH-MYB complexes is in part determined by interacting proteins, such as PH3 and TTG2, and reveal an unanticipated similarity in the regulatory circuitry that controls petunia vacuolar acidification and Arabidopsis hair development. © 2016 American Society of Plant Biologists. All rights reserved.

  19. Pontine and Thalamic Influences on Fluid Rewards: I. Operant Responding for Sucrose and Corn Oil

    Science.gov (United States)

    Liang, Nu-Chu; Freet, Christopher S.; Grigson, Patricia S; Norgren, Ralph

    2011-01-01

    The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil. PMID:21703290

  20. Nanoscale domain formation of phosphatidylinositol 4-phosphate in the plasma and vacuolar membranes of living yeast cells.

    Science.gov (United States)

    Tomioku, Kan-Na; Shigekuni, Mikiko; Hayashi, Hiroki; Yoshida, Akane; Futagami, Taiki; Tamaki, Hisanori; Tanabe, Kenji; Fujita, Akikazu

    2018-05-01

    In budding yeast Saccharomyces cerevisiae, PtdIns(4)P serves as an essential signalling molecule in the Golgi complex, endosomal system, and plasma membrane, where it is involved in the control of multiple cellular functions via direct interactions with PtdIns(4)P-binding proteins. To analyse the distribution of PtdIns(4)P in yeast cells at a nanoscale level, we employed an electron microscopy technique that specifically labels PtdIns(4)P on the freeze-fracture replica of the yeast membrane. This method minimizes the possibility of artificial perturbation, because molecules in the membrane are physically immobilised in situ. We observed that PtdIns(4)P is localised on the cytoplasmic leaflet, but not the exoplasmic leaflet, of the plasma membrane, Golgi body, vacuole, and vesicular structure membranes. PtdIns(4)P labelling was not observed in the membrane of the endoplasmic reticulum, and in the outer and inner membranes of the nuclear envelope or mitochondria. PtdIns(4)P forms clusters of plasma membrane and vacuolar membrane according to point pattern analysis of immunogold labelling. There are three kinds of compartments in the cytoplasmic leaflet of the plasma membrane. In the present study, we showed that PtdIns(4)P is specifically localised in the flat undifferentiated plasma membrane compartment. In the vacuolar membrane, PtdIns(4)P was concentrated in intramembrane particle (IMP)-deficient raft-like domains, which are tightly bound to lipid droplets, but not surrounding IMP-rich non-raft domains in geometrical IMP-distributed patterns in the stationary phase. This is the first report showing microdomain formations of PtdIns(4)P in the plasma membrane and vacuolar membrane of budding yeast cells at a nanoscale level, which will illuminate the functionality of PtdIns(4)P in each membrane. Copyright © 2018 Elsevier GmbH. All rights reserved.

  1. Vacuolar H+-ATPase Protects Saccharomyces cerevisiae Cells against Ethanol-Induced Oxidative and Cell Wall Stresses.

    Science.gov (United States)

    Charoenbhakdi, Sirikarn; Dokpikul, Thanittra; Burphan, Thanawat; Techo, Todsapol; Auesukaree, Choowong

    2016-05-15

    During fermentation, increased ethanol concentration is a major stress for yeast cells. Vacuolar H(+)-ATPase (V-ATPase), which plays an important role in the maintenance of intracellular pH homeostasis through vacuolar acidification, has been shown to be required for tolerance to straight-chain alcohols, including ethanol. Since ethanol is known to increase membrane permeability to protons, which then promotes intracellular acidification, it is possible that the V-ATPase is required for recovery from alcohol-induced intracellular acidification. In this study, we show that the effects of straight-chain alcohols on membrane permeabilization and acidification of the cytosol and vacuole are strongly dependent on their lipophilicity. These findings suggest that the membrane-permeabilizing effect of straight-chain alcohols induces cytosolic and vacuolar acidification in a lipophilicity-dependent manner. Surprisingly, after ethanol challenge, the cytosolic pH in Δvma2 and Δvma3 mutants lacking V-ATPase activity was similar to that of the wild-type strain. It is therefore unlikely that the ethanol-sensitive phenotype of vma mutants resulted from severe cytosolic acidification. Interestingly, the vma mutants exposed to ethanol exhibited a delay in cell wall remodeling and a significant increase in intracellular reactive oxygen species (ROS). These findings suggest a role for V-ATPase in the regulation of the cell wall stress response and the prevention of endogenous oxidative stress in response to ethanol. The yeast Saccharomyces cerevisiae has been widely used in the alcoholic fermentation industry. Among the environmental stresses that yeast cells encounter during the process of alcoholic fermentation, ethanol is a major stress factor that inhibits yeast growth and viability, eventually leading to fermentation arrest. This study provides evidence for the molecular mechanisms of ethanol tolerance, which is a desirable characteristic for yeast strains used in alcoholic

  2. Effect of external pH on the cytoplasmic and vacuolar pHs in Mung bean root-tip cells

    International Nuclear Information System (INIS)

    Torimitsu, Keiichi; Yazaki, Yoshiaki; Nagasuka, Kinuyo; Ohta, Eiji; Sakata, Makoto

    1984-01-01

    The effect of the external pH on the intracellular pH in mung bean (Vigna mungo (L.) Hepper) root-tip cells was investigated with the 31 P nuclear magnetic resonance (NMR) method. The 31 P NMR spectra showed three peaks caused by cytoplasmic G-6-P, cytoplasmic Psub(i) and vacuolar Psub(i). The cytoplasmic and vacuolar pHs could be determined by comparing the Psub(i) chemical shifts with the titration curve. When the external pH was changed over a range from pH 3 to 10, the cytoplasmic pH showed smaller changes than the vacuolar pH, suggesting that the former is regulated more strictly than the latter. The H + -ATPase inhibitor, DCCD, caused the breakdown of the mechanism that regulates the intracellular pH. H + -ATPase appears to have an important part in the regulation of the intracellular pH. (author)

  3. Crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis

    DEFF Research Database (Denmark)

    Sprogøe, Desiree; van den Broek, Lambertus A M; Mirza, Osman

    2004-01-01

    phosphorylase from Bifidobacterium adolescentis (BiSP) refined at 1.77 A resolution. It represents the first 3D structure of a sucrose phosphorylase and is the first structure of a phosphate-dependent enzyme from the glycoside hydrolase family 13. The structure of BiSP is composed of the four domains A, B, B...... binding and reduces the size of the substrate access channel compared to other family 13 members, underlining the role of this domain in modulating the function of these enzymes. It is remarkable that the fold of the C domain is not observed in any other known hydrolases of family 13. BiSP was found...

  4. Increasing Sucrose Uptake Capacity of Wheat Grains Stimulates Storage Protein Synthesis1[W

    Science.gov (United States)

    Weichert, Nicola; Saalbach, Isolde; Weichert, Heiko; Kohl, Stefan; Erban, Alexander; Kopka, Joachim; Hause, Bettina; Varshney, Alok; Sreenivasulu, Nese; Strickert, Marc; Kumlehn, Jochen; Weschke, Winfriede; Weber, Hans

    2010-01-01

    Increasing grain sink strength by improving assimilate uptake capacity could be a promising approach toward getting higher yield. The barley (Hordeum vulgare) sucrose transporter HvSUT1 (SUT) was expressed under control of the endosperm-specific Hordein B1 promoter (HO). Compared with the wild type, transgenic HOSUT grains take up more sucrose (Suc) in vitro, showing that the transgene is functional. Grain Suc levels are not altered, indicating that Suc fluxes are influenced rather than steady-state levels. HOSUT grains have increased percentages of total nitrogen and prolamins, which is reflected in increased levels of phenylalanine, tyrosine, tryptophan, isoleucine, and leucine at late grain development. Transcript profiling indicates specific stimulation of prolamin gene expression at the onset of storage phase. Changes in gene expression and metabolite levels related to carbon metabolism and amino acid biosynthesis suggest deregulated carbon-nitrogen balance, which together indicate carbon sufficiency and relative depletion of nitrogen. Genes, deregulated together with prolamin genes, might represent candidates, which respond positively to assimilate supply and are related to sugar-starch metabolism, cytokinin and brassinosteroid functions, cell proliferation, and sugar/abscisic acid signaling. Genes showing inverse expression patterns represent potential negative regulators. It is concluded that HvSUT1 overexpression increases grain protein content but also deregulates the metabolic status of wheat (Triticum aestivum) grains, accompanied by up-regulated gene expression of positive and negative regulators related to sugar signaling and assimilate supply. In HOSUT grains, alternating stimulation of positive and negative regulators causes oscillatory patterns of gene expression and highlights the capacity and great flexibility to adjust wheat grain storage metabolism in response to metabolic alterations. PMID:20018590

  5. Mechanisms of Sucrose and Non-Nutritive Sucking in Procedural Pain Management in Infants

    Directory of Open Access Journals (Sweden)

    Sharyn Gibbins

    2001-01-01

    Full Text Available The administration of sucrose with and without non-nutritive sucking (NNS has been examined for relieving procedural pain in newborn infants. The calming and pain-relieving effects of sucrose are thought to be mediated by endogenous opioid pathways activated by sweet taste. The orogustatory effects of sucrose have been demonstrated in animal newborns, and in preterm and full term human infants during painful procedures. In contrast to sucrose, the analgesic effects of NNS are hypothesized to be activated through nonopioid pathways by stimulation of orotactile and mechanoreceptor mechanisms. Although there is uncertainty as to whether the effects of sucrose and NNS are synergistic or additive, there is sufficient evidence to support the efficacy of combining the two interventions for procedural pain relief in infants. In this review article, the underlying mechanisms of sucrose and NNS, separately and in combination for relieving procedural pain in preterm and full term infants, are examined. Clinical and research implications are addressed.

  6. A sucrose-rich diet induces mutations in the rat colon

    DEFF Research Database (Denmark)

    Dragsted, L.O.; Daneshvar, B.; Vogel, Ulla Birgitte

    2002-01-01

    A sucrose-rich diet has repeatedly been observed to have cocarcinogenic actions in the colon and liver of rats and to increase the number of aberrant crypt foci in rat colon. To investigate whether sucrose-rich diets might directly increase the genotoxic response in the rat colon or liver, we have...... or in blood plasma. We conclude that a sucrose-rich diet directly or indirectly increases the mutation frequency in rat colon in a dose-dependent manner and concomitantly decreases the level of background DNA adducts, without a direct effect on the expression of major DNA repair enzyme systems. We also...... conclude that an oxidative mechanism for this effect of sucrose is unlikely. This is the first demonstration of a genotoxic action of increased dietary sucrose in vivo. Both sucrose intake and colon cancer rates are high in the Western world, and our present results call for an examination of a possible...

  7. Study on the preparation and characterization of sucrose-LDPE sheet for radiation dosimeter

    International Nuclear Information System (INIS)

    Ki, Yup Kim; Hwang, In Ra; Kyung, Young Lee

    2008-01-01

    To improve the dosimetry performance of sucrose, we investigated the possibility of a radiation detector with the sucrose/polymer composite. For this purpose we manufactured the sucrose/polyethylene composite for dosimetry system and investigated the suitable manufacture conditions of that. The possibility of sample for dosimetry system was measured by EPR and chemiluminescence. The sample had a possibility of dosimetry system from the experimental results. (author)

  8. Varietal performance of potato on induction and development of microtuber in response to sucrose

    Directory of Open Access Journals (Sweden)

    Md. Sadek Hossain

    2017-06-01

    Full Text Available Tissue culture techniques are the most momentous and extensively method to produce disease-free quality plantlets and microtubers in potato. In spite of this, there has been a lack of research information into in vitro microtuberization for seed tuber production program in Bangladesh. In this experiment, we assessed the appropriateness of different concentrations of sucrose with especial accent on their effects for induction and development of microtuber in potato varieties. In vitro plantlets of three potato varieties; Asterix, Granola, and Diamant were treated with eight level of sucrose as 0, 3, 4, 6, 8, 10, 12 and 14% for 70 days of incubation producing microtuber. Asterix induces microtuber after 10.69 days, it was statistically shorter duration than other two varieties. Tuberization did not occur without sucrose and were required a minimum (8.92 days with 8% sucrose, while it delayed with either increasing or decreasing rate of sucrose concentration. A single number of microtuber was not formed in absence of sucrose after 28 days of incubation. Microtuber plantlet−1 was the highest more or less in all varieties at harvest with 8% sucrose concentration. Hundred percent of microtuber below 250 mg induced in 3% sucrose concentration and from then the microtuber grade induction decreased with the increase of sucrose concentration. >500 mg grade microtuber produced by Granola (47.95% with 10% sucrose while Diamant produced 50.15% above 500 mg grade microtuber with 14% sucrose. It is also noticeable by Astrerix variety where >500 mg microtuber were produced about 46.95% with 8% sucrose.

  9. Dimerization effect of sucrose octasulfate on rat FGF1

    International Nuclear Information System (INIS)

    Kulahin, N.; Kiselyov, V.; Kochoyan, A.; Kristensen, O.; Kastrup, Jette S.; Berezin, V.; Bock, E.; Gajhede, M.

    2008-01-01

    The work describes the sucrose octasulfate-mediated dimerization of rat FGF1 by gel-filtration experiments and crystal structure determination. Fibroblast growth factors (FGFs) constitute a family of at least 23 structurally related heparin-binding proteins that are involved in regulation of cell growth, survival, differentiation and migration. Sucrose octasulfate (SOS), a chemical analogue of heparin, has been demonstrated to activate FGF signalling pathways. The structure of rat FGF1 crystallized in the presence of SOS has been determined at 2.2 Å resolution. SOS-mediated dimerization of FGF1 was observed, which was further supported by gel-filtration experiments. The major contributors to the sulfate-binding sites in rat FGF1 are Lys113, Lys118, Arg122 and Lys128. An arginine at position 116 is a consensus residue in mammalian FGF molecules; however, it is a serine in rat FGF1. This difference may be important for SOS-mediated FGF1 dimerization in rat

  10. Body weight manipulation, reinforcement value and choice between sucrose and wheel running: a behavioral economic analysis.

    Science.gov (United States)

    Belke, Terry W; Pierce, W David

    2009-02-01

    Twelve female Long-Evans rats were exposed to concurrent variable (VR) ratio schedules of sucrose and wheel-running reinforcement (Sucrose VR 10 Wheel VR 10; Sucrose VR 5 Wheel VR 20; Sucrose VR 20 Wheel VR 5) with predetermined budgets (number of responses). The allocation of lever pressing to the sucrose and wheel-running alternatives was assessed at high and low body weights. Results showed that wheel-running rate and lever-pressing rates for sucrose and wheel running increased, but the choice of wheel running decreased at the low body weight. A regression analysis of relative consumption as a function of relative price showed that consumption shifted toward sucrose and interacted with price differences in a manner consistent with increased substitutability. Demand curves showed that demand for sucrose became less elastic while demand for wheel running became more elastic at the low body weight. These findings reflect an increase in the difference in relative value of sucrose and wheel running as body weight decreased. Discussion focuses on the limitations of response rates as measures of reinforcement value. In addition, we address the commonalities between matching and demand curve equations for the analysis of changes in relative reinforcement value.

  11. Combined compared to dissociated oral and intestinal sucrose stimuli induce different brain hedonic processes

    Science.gov (United States)

    Clouard, Caroline; Meunier-Salaün, Marie-Christine; Meurice, Paul; Malbert, Charles-Henri; Val-Laillet, David

    2014-01-01

    The characterization of brain networks contributing to the processing of oral and/or intestinal sugar signals in a relevant animal model might help to understand the neural mechanisms related to the control of food intake in humans and suggest potential causes for impaired eating behaviors. This study aimed at comparing the brain responses triggered by oral and/or intestinal sucrose sensing in pigs. Seven animals underwent brain single photon emission computed tomography (99mTc-HMPAO) further to oral stimulation with neutral or sucrose artificial saliva paired with saline or sucrose infusion in the duodenum, the proximal part of the intestine. Oral and/or duodenal sucrose sensing induced differential cerebral blood flow changes in brain regions known to be involved in memory, reward processes and hedonic (i.e., pleasure) evaluation of sensory stimuli, including the dorsal striatum, prefrontal cortex, cingulate cortex, insular cortex, hippocampus, and parahippocampal cortex. Sucrose duodenal infusion only and combined sucrose stimulation induced similar activity patterns in the putamen, ventral anterior cingulate cortex and hippocampus. Some brain deactivations in the prefrontal and insular cortices were only detected in the presence of oral sucrose stimulation. Finally, activation of the right insular cortex was only induced by combined oral and duodenal sucrose stimulation, while specific activity patterns were detected in the hippocampus and parahippocampal cortex with oral sucrose dissociated from caloric load. This study sheds new light on the brain hedonic responses to sugar and has potential implications to unravel the neuropsychological mechanisms underlying food pleasure and motivation. PMID:25147536

  12. [14C]sucrose uptake and labeling of starch in developing grains of normal segl barley

    International Nuclear Information System (INIS)

    Felker, F.C.; Peterson, D.M.; Nelson, O.E.

    1984-01-01

    Previous work showed that the segl mutant of barley (Hordeum vulgare o Betzes) did not differ from normal Betzes in plant growth, photosynthesis, or fertility, but it produced only shrunken seeds regardless of pollen source. To determine whether defects in sucrose uptake or starch synthesis resulted in the shrunken condition, developing grains of Betzes and segl were cultured in [ 14 C]sucrose solutions after slicing transversely to expose the endosperm cavity and free space. In both young grains (before genotypes differed in dry weight) and older grains (17 days after anthesis, when segl grains were smaller than Betzes), sucrose uptake and starch synthesis were similar in both genotypes on a dry weight basis. To determine if sucrose was hydrolyzed during uptake, spikes of Betzes and segl were allowed to take up [fructose-U- 14 C]sucrose 14 days after anthesis and the radioactivity of endosperm sugars was examined during 3 hours of incubation. Whereas less total radioactivity entered the endosperm and the endosperm cavity (free space) of segl, in both genotypes over 96% of the label of endosperm sugars was in sucrose, and there was no apparent initial or progressive randomization of label among hexose moieties of sucrose as compared to the free space sampled after 1 hour of incubation. The authors conclude that segl endosperms are capable of normal sucrose uptake and starch synthesis and that hydrolysis of sucrose is not required for uptake in either genotype. Evidence suggests abnormal development of grain tissue of maternal origin during growth of segl grains

  13. Sucrose delays senescence and preserves functional compounds in Asparagus officinalis L.

    Science.gov (United States)

    Park, Me-Hea

    2016-11-11

    The high metabolic rate of harvested asparagus spears (Asparagus officinalis L.) causes rapid deterioration. To extend shelf life, we investigated the effect of sucrose treatment on asparagus during storage. Asparagus spears were treated with 3%, 5%, and 10% sucrose and stored at 2 °C for 20 h. Cellular respiration decreased, but other processes were unaltered by exogenous sucrose. The overall appearance of asparagus treated with 3% sucrose and stored at 2 °C for 18 days was rated as good and excellent, unlike that of untreated spears. Asparagus treated with sucrose maintained firmness for 15 days, while untreated spears lost firmness and showed increased water-soluble pectin content during storage. Carbohydrate levels were also higher in sucrose-treated than in control samples. Transcript levels of cell-wall-related genes, including xyloglucan endotransglycosylase (XET)1, XET2, and peroxidase (prx)1, prx2, and prx3 were upregulated by sucrose. Cyanidin 3-O-rutinoside and rutin levels immediately increased upon addition of sucrose and remained high relative to the control during storage. Thus, sucrose modulates asparagus cell wall components and maintains the functionality of important compounds during storage, thus effectively prolonging shelf life. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  14. Pep3p/Pep5p complex: a putative docking factor at multiple steps of vesicular transport to the vacuole of Saccharomyces cerevisiae.

    OpenAIRE

    Srivastava, A; Woolford, C A; Jones, E W

    2000-01-01

    Pep3p and Pep5p are known to be necessary for trafficking of hydrolase precursors to the vacuole and for vacuolar biogenesis. These proteins are present in a hetero-oligomeric complex that mediates transport at the vacuolar membrane. PEP5 interacts genetically with VPS8, implicating Pep5p in the earlier Golgi to endosome step and/or in recycling from the endosome to the Golgi. To understand further the cellular roles of Pep3p and Pep5p, we isolated and characterized a set of pep3 conditional ...

  15. Using biomass of starch-rich transgenic Arabidopsis vacuolar as feedstock for fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Yung-Chung; Cheng, Chieh-Lun; Chen, Chun-Yen [National Cheng Kung Univ., Tainan, Taiwan (China). Dept. of Chemical Engineering; Huang, Li-Fen; Chang, Jo-Shu [Yuan Ze Univ., Tao-yuan, Taiwan (China). Graduate School of Biotechnology and Bioengineering

    2010-07-01

    Cellulose is the major constitute of plant biomass and highly available in agricultural wastes and industrial effluents, thereby being a cost-effective feedstock for bioenergy production. However, most hydrogen producing bacteria (HPB) could not directly convert cellulosic materials (such as rice husk and rice straw) into hydrogen whereas most HPB could utilize sugar and starch for hydrogen production. In this work, we used an indigenous bacterial isolate Clostridium butyricum CGS2 as HPB, which could directly convert soluble starch into H2 with a maximum H2 production rate and a H2 yield of 205.07 ml H2/h/l and 6.46 mmol H2/g starch, respectively. However, C. butyricum CGS2 could not ferment pure cellulosic materials such as carboxymethyl cellulose and xylan. Moreover, we found that C. butyricum CGS2 could utilize rich husk to produce H2 at a rate of 13.19 ml H2/h/l due to the starch content in rice husk (H2 yield = 1.49 mmol H2/g rice husk). In contrast, since lacking starch content, rice straw cannot be converted to H2 by C. butyricum CGS2. The foregoing results suggest that increasing the starch content in the natural agricultural wastes may make them better feedstock for fermentative H2 production. Hence, a genetically modified plant (Arabidopsis vacuolar) was constructed to enhance its starch concentration. The starch concentration of mutant plant S1 increased to 10.67 mg/fresh weight, which is four times higher than that of wild type plant. Using mutant plant S1 as carbon source, C. butyricum CGS2 was able to give a high cumulative H2 production and H2 production rate of 285.4 ml H2/l and 43.6 ml/h/l, respectively. The cumulative H2 production and H2 production rate both increased when the concentration of the transgenic plant was increased. Therefore, this study successful demonstrated the feasibility of expressing starch on genetically-modified plants to create a more effective feedstock for dark H2 fermentation. (orig.)

  16. Phytoremediation potential of Arabidopsis thaliana, expressing ectopically a vacuolar proton pump, for the industrial waste phosphogypsum.

    Science.gov (United States)

    Khoudi, Habib; Maatar, Yafa; Brini, Faïçal; Fourati, Amine; Ammar, Najoua; Masmoudi, Khaled

    2013-01-01

    transgenic A. thaliana lines were more Cd-tolerant than the WT plants. These results suggested that ectopic expression of a vacuolar proton pump in A. thaliana plants can lead to various biotechnological applications including the phytoremediation of industrial wastes.

  17. Involvement of Vacuolar Sequestration and Active Transport in Tolerance of Saccharomyces cerevisiae to Hop Iso-?-Acids

    NARCIS (Netherlands)

    Hazelwood, L.A.; Walsh, M.C.; Pronk, J.T.; Daran, J.M.

    2009-01-01

    The hop plant, Humulus lupulus L., has an exceptionally high content of secondary metabolites, the hop -acids, which possess a range of beneficial properties, including antiseptic action. Studies performed on the mode of action of hop iso--acids have hitherto been restricted to lactic acid bacteria.

  18. Encoding of Sucrose's Palatability in the Nucleus Accumbens Shell and Its Modulation by Exteroceptive Auditory Cues

    Directory of Open Access Journals (Sweden)

    Miguel Villavicencio

    2018-05-01

    Full Text Available Although the palatability of sucrose is the primary reason for why it is over consumed, it is not well understood how it is encoded in the nucleus accumbens shell (NAcSh, a brain region involved in reward, feeding, and sensory/motor transformations. Similarly, untouched are issues regarding how an external auditory stimulus affects sucrose palatability and, in the NAcSh, the neuronal correlates of this behavior. To address these questions in behaving rats, we investigated how food-related auditory cues modulate sucrose's palatability. The goals are to determine whether NAcSh neuronal responses would track sucrose's palatability (as measured by the increase in hedonically positive oromotor responses lick rate, sucrose concentration, and how it processes auditory information. Using brief-access tests, we found that sucrose's palatability was enhanced by exteroceptive auditory cues that signal the start and the end of a reward epoch. With only the start cue the rejection of water was accelerated, and the sucrose/water ratio was enhanced, indicating greater palatability. However, the start cue also fragmented licking patterns and decreased caloric intake. In the presence of both start and stop cues, the animals fed continuously and increased their caloric intake. Analysis of the licking microstructure confirmed that auditory cues (either signaling the start alone or start/stop enhanced sucrose's oromotor-palatability responses. Recordings of extracellular single-unit activity identified several distinct populations of NAcSh responses that tracked either the sucrose palatability responses or the sucrose concentrations by increasing or decreasing their activity. Another neural population fired synchronously with licking and exhibited an enhancement in their coherence with increasing sucrose concentrations. The population of NAcSh's Palatability-related and Lick-Inactive neurons were the most important for decoding sucrose's palatability. Only the Lick

  19. Vacuolar ATPases, like F1,F0-ATPases, show a strong dependence of the reaction velocity on the binding of more than one ATP per enzyme

    International Nuclear Information System (INIS)

    Kasho, V.N.; Boyer, P.D.

    1989-01-01

    Recent studies with vacuolar ATPases have shown that multiple copies catalytic subunits are present and that these have definite sequence homology with catalytic subunits of the F 1 , F 0 -ATPases. Experiments are reported that assess whether the vacuolar ATPases may have the unusual catalytic cooperativity with sequential catalytic site participation as in the binding change mechanism for the F 1 ,F 0 -ATPases. The extent of reversal of bound ATP hydrolysis to bound ADP and P i as medium ATP concentration was lowered was determined by 18 O-exchange measurements for yeast and neurospora vacuolar ATPases. The results show a pronounced increase in the extent of water oxygen incorporation into the P i formed as ATP concentration is decreased to the micromolar range. The F 1 ,F 0 -ATPase from neurospora mitochondria showed an event more pronounced modulation, similar to that of other F 1 -type ATPases. The vacuolar ATPases thus appear to have a catalytic mechanism quite analogous to that of the F 1 ,F 0 -ATPases

  20. The vacuolar V1/V0-ATPase is involved in the release of the HOPS subunit Vps41 from vacuoles, vacuole fragmentation and fusion

    DEFF Research Database (Denmark)

    Takeda, Kozue; Cabrera, Margarita; Rohde, Jan

    2008-01-01

    At yeast vacuoles, phosphorylation of the HOPS subunit Vps41 depends on the Yck3 kinase. In a screen for mutants that mimic the yck3Delta phenotype, in which Vps41 accumulates in vacuolar dots, we observed that mutants in the V0-part of the V0/V1-ATPase, in particular in vma16Delta, also accumulate...

  1. Fructose and Sucrose Intake Increase Exogenous Carbohydrate Oxidation during Exercise

    Science.gov (United States)

    Trommelen, Jorn; Fuchs, Cas J.; Beelen, Milou; Lenaerts, Kaatje; Jeukendrup, Asker E.; Cermak, Naomi M.; van Loon, Luc J. C.

    2017-01-01

    Peak exogenous carbohydrate oxidation rates typically reach ~1 g·min−1 during exercise when ample glucose or glucose polymers are ingested. Fructose co-ingestion has been shown to further increase exogenous carbohydrate oxidation rates. The purpose of this study was to assess the impact of fructose co-ingestion provided either as a monosaccharide or as part of the disaccharide sucrose on exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. Ten trained male cyclists (VO2peak: 65 ± 2 mL·kg−1·min−1) cycled on four different occasions for 180 min at 50% Wmax during which they consumed a carbohydrate solution providing 1.8 g·min−1 of glucose (GLU), 1.2 g·min−1 glucose + 0.6 g·min−1 fructose (GLU + FRU), 0.6 g·min−1 glucose + 1.2 g·min−1 sucrose (GLU + SUC), or water (WAT). Peak exogenous carbohydrate oxidation rates did not differ between GLU + FRU and GLU + SUC (1.40 ± 0.06 vs. 1.29 ± 0.07 g·min−1, respectively, p = 0.999), but were 46% ± 8% higher when compared to GLU (0.96 ± 0.06 g·min−1: p exogenous carbohydrate oxidation rates during the latter 120 min of exercise were 46% ± 8% higher in GLU + FRU or GLU + SUC compared with GLU (1.19 ± 0.12, 1.13 ± 0.21, and 0.82 ± 0.16 g·min−1, respectively, p exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. PMID:28230742

  2. Sucrose Synthase Is Associated with the Cell Wall of Tobacco Pollen Tubes

    NARCIS (Netherlands)

    Persia, D.; Cai, G.; Casino, C.; Willemse, M.T.M.; Cresti, M.

    2008-01-01

    Sucrose synthase (Sus; EC 2.4.1.13) is a key enzyme of sucrose metabolism in plant cells, providing carbon for respiration and for the synthesis of cell wall polymers and starch. Since Sus is important for plant cell growth, insights into its structure, localization, and features are useful for

  3. Coordination of sucrose uptake and respiration in the yeast Debaryomyces yamadae

    NARCIS (Netherlands)

    Kaliterna, J.; Weusthuis, R.A.; Castrillo, J.I.; Dijken, van J.P.; Pronk, J.T.

    1995-01-01

    Screening in batch cultures identified Debaryomyces yamadae as a yeast that exhibits the Kluyver effect for sucrose: this disaccharide can be respired but, even under oxygen-limited conditions, alcoholic fermentation of sucrose does not occur. Ethanol, glycerol and arabitol were the main

  4. Influence of concentration of sucrose on the acetone-butanol fermentation by different strains of Clostridium

    Energy Technology Data Exchange (ETDEWEB)

    Bahadue, K; Saroj, K K

    1959-01-01

    To culture media containing (NH/sub 4/)/sub 2/SO/sub 4/ (0.34 g) and MgSO/sub 4/ (0.16 g), were added 5, 10, and 20% sucrose, respectively; the pH was adjusted to 6.4 with KH/sub 2/PO/sub 4/-NaOH buffer; the volume of each medium was made up to 200 ml. The media were sterilized. After cooling, the media at the 5, 10, 20% sucrose levels were inoculated separately with C. butyricum, C. butyricum 6084, C. acetobutylicum NRRL B-527, C. pasteurianum NRRL B-598, C. butylicus NRRL B-592, and C. pasteurianum ATCC 6013. The cultures were incubated for 20 days at 35 degrees. For maximum butanol yield the 5% sucrose level was optimum for all the strains tested. At the 10% sucrose level great increase in sugar consumption occurred with C. butyricum Frolund, C. pasteurianum ATCC-6013, and C. butylicus IAL 15-152. Twice as much sucrose was consumed with C. acetobutylicum ATCC 6013, and NRRL B-572, and C. pasteurianum NRRL B-598. The increased sucrose consumption did not result in increased production of butanol or acetone. No acetone or butanol was formed with C. butyricum Frolund when the sucrose concentration was increased from 5 to 10%. With the increase in sucrose concentration, the formation of butanol and acetone decreased; acid formation was also inhibited.

  5. Influence of concentration of sucrose on the acetone-butanol fermentation by different strains of Clostridium

    Energy Technology Data Exchange (ETDEWEB)

    Bahadur, K; Saroj, K K

    1959-01-01

    To culture media containing (NH/sub 4/)/sub 2/SO/sub 4/ (0.34 g) and MgSO/sub 4/ (0.16 g), were added 5, 10, and 20% sucrose, respectively; the pH was adjusted to 6.4 with KH/sub 2/PO/sub 4/-NaOH buffer; the volume of each medium was made up to 200 ml. The media were sterilized. After cooling, the media at the 5, 10, 20% sucrose levels were inoculated separately with C. butyricum, C. butyricum 6084, C. acetobutylicum NRRL B-527, C. pasteurianum NRRL B-598, C. butylicus NRRL B-592, nd C. pasteurianum ATCC 6013. The cultures were incubated for 20 days at 35/sup 0/. For maximum BuOH yield the 5% sucrose level was optimum for all the strains tested. At the 10% sucrose level great increase in sugar consumption occurred with C. butyricum Frolund, C. pasteurianum ATCC-6013, and C. butylicus IAL 15-152. Twice as much sucrose was consumed with C. acetobutylicum ATCC 10132, and NRRL B-572, and C. pasteurianum NRRL B-598. The increased sucrose consumption did not result in increased production of BuOH or acetone. No acetone or BuOH was formed with C. butyricum Frolund when the sucrose concentration was increased from 5 to 10%. With the increase in sucrose concentration, the formation of BuH and acetone decreased; acid formation was also inhibited.

  6. Effect of gel texture and sucrose spatial distribution on sweetness perception

    NARCIS (Netherlands)

    Mosca, A.C.; Velde, van de F.; Bult, J.H.F.; Boekel, van M.A.J.S.; Stieger, M.A.

    2012-01-01

    Layered gels differing in mechanical and breakdown properties (soft, medium and hard gels) and in the distribution of sucrose in the matrix (homogeneous and inhomogeneous distributions) were used to investigate the effects of texture and spatial distribution of sucrose on sweetness perception.

  7. Oxytocin differentially affects sucrose taking and seeking in male and female rats.

    Science.gov (United States)

    Zhou, Luyi; Ghee, Shannon M; See, Ronald E; Reichel, Carmela M

    2015-04-15

    Oxytocin has a modulatory role in natural and drug reward processes. While the role of oxytocin in pair bonding and reproduction has been extensively studied, sex differences in conditioned and unconditioned behavioral responses to oxytocin treatment have not been fully characterized. Here, we determined whether male and female rats would show similar dose response curves in response to acute oxytocin on measures of locomotor activity, sucrose seeking, and sucrose intake. Male and freely cycling female rats received vehicle or oxytocin (0.1, 0.3, 1, 3mg/kg, IP) injections before behavioral tests designed to assess general motor activity, as well as sucrose self-administration and seeking. Lower doses of oxytocin decreased motor activity in a novel environment in females relative to males. Likewise, lower doses of oxytocin in females decreased responding for sucrose during maintenance of sucrose self-administration and reinstatement to sucrose-conditioned cues. However, sucrose seeking in response to a sucrose prime was only decreased by the highest oxytocin dose in both sexes. In general, oxytocin had similar effects in both sexes. However, females were more sensitive to lower doses of oxytocin than males. These findings are consistent with the notion that oxytocin regulates many of the same behaviors in males and females, but that the effects are typically more profound in females. Therapeutic use of oxytocin should include sex as a factor in determining dose regimens. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Evidence for the presence of a sucrose carrier in immature sugar-beet roots

    International Nuclear Information System (INIS)

    Lemoine, R.; Daie, J.; Wyse, R.

    1987-01-01

    Unlike in mature sugar-beet roots, sucrose is assumed to be hydrolyzed by a wall-bound invertase prior to uptake by immature roots. To test this hypothesis, they used a sucrose analog, 1'fluorosucrose which is recognized by the carrier but is a poor substrate for invertases. Asymmetrically labeled sucrose ( 3 H-fructose) 1'fluorosucrose ( 14 C-glucose) were applied at 10 mM ( 3 H/ 14 C=1) to an attached source leaf. After 6 h, sugars from plant parts in the translocation path were separated on HPLC. 14 C-1'fluorosucrose was translocated and accumulated in the root at a higher rate than 3 H-sucrose due to greater metabolism of 3 H-sucrose in the shoot (indicated by the presence of 3 H in hexose fractions and loss of asymmetry). In the root 25% of the 3 H-sucrose was hydrolyzed to hexoses whereas no 14 C was detected in hexose fractions. The data indicate that despite high cell-wall invertase and cytoplasmic sucrose synthase activities, young sugar-beet roots import and store sucrose without hydrolysis. Therefore, the function of a group translocator at the tonoplast is unclear

  9. Dextran-induced depletion flocculation in oil-water emulsions in the presence of sucrose

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Zoet, F.D.; Vliet, van T.; Linden, van der E.; Aken, van G.A.

    2004-01-01

    The phase behaviour and mechanical properties of 10 wt% oil-in-water emulsions, stabilised by ß-lactoglobulin (ß-lg) and flocculated by the polysaccharide dextran were studied as a function of sucrose concentration. The sucrose concentration affected neither the polysaccharide concentration above

  10. Rats' preferences for high fructose corn syrup vs. sucrose and sugar mixtures.

    Science.gov (United States)

    Ackroff, Karen; Sclafani, Anthony

    2011-03-28

    High fructose corn syrup (HFCS) has replaced sucrose in many food products, which has prompted research comparing these two sweeteners in rodents. The present study examined the relative palatability of HFCS and sucrose for rats, offering 11% carbohydrate solutions to match the content of common beverages for human consumption. The animals initially preferred HFCS to sucrose but after separate experience with each solution they switched to sucrose preference. Approximating the composition of HFCS with a mixture of fructose and glucose (55:45) yielded a solution that was less attractive than sucrose or HFCS. However, HFCS contains a small amount of glucose polymers, which are very attractive to rats. A 55:42:3 mixture of fructose, glucose and glucose polymers (Polycose) was equally preferred to HFCS and was treated similarly to HFCS in comparisons vs. sucrose. Post-oral effects of sucrose, which is 50% fructose and 50% glucose, may be responsible for the shift in preference with experience. This shift, and the relatively small magnitude of differences in preference for HFCS and sucrose, suggest that palatability factors probably do not contribute to any possible difference in weight gain responses to these sweeteners. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Isolation, Fractionation, and Identification of Sucrose Esters from Various Oriental Tobaccos Employing Supercritical Fluids

    Directory of Open Access Journals (Sweden)

    Ashraf-Khorassani M

    2014-12-01

    Full Text Available Isolation, fractionation, and identification of sucrose esters from aged oriental tobacco employing supercritical fluids have been completed. Underivatized sucrose ester-rich extracts were obtained using supercritical CO2 at densities greater than 0.73 g/mL. Lower density CO2 provided extracts with notable amounts of tobacco derived material; yet, no detectable sucrose ester content. Preparative supercritical fluid chromatography (SFC provided for an additional purification of the sucrose ester-enriched fraction after column optimization. Structural assignments of the SFC fractions were facilitated using gas chromatography/mass spectrometry (GC/MS accompanied by N, O-bis(trimethylsilyltrifluoroacetamide-dimethylformamide (BSTFA-DMF derivatization of the free hydroxyl groups and high performance-liquid chromatography/mass spectrometry (HPLC/MS. From a relative quantitative perspective regardless of tobacco type, sucrose esters having an acetyl group on C6 of the glucose function (Group III were in higher concentration compared to both the concentration observed for sucrose ester of Group I (acetyl group on C3 of fructose and sucrose ester of Group II (no acetyl group on either glucose or fructose. Saturated fatty acid constituents were found to range from a maximum total of 18 carbons to a minimum total of 13 carbons. Unsaturated and isomeric fatty acid homologues were detected within the Group II sucrose ester.

  12. Phenotypic and Genotypic Characterization of Virulent Yersinia enterocolitica Strains Unable To Ferment Sucrose

    Science.gov (United States)

    Guiyoule, Annie; Guinet, Françoise; Martin, Liliane; Benoit, Catherine; Desplaces, Nicole; Carniel, Elisabeth

    1998-01-01

    Several atypical sucrose-negative Yersinia strains, isolated from clinical samples and sometimes associated with symptoms, proved to have full virulence potential in in vitro and in vivo testings. DNA-relatedness studies revealed that they were authentic Yersinia enterocolitica strains. Therefore, atypical sucrose-negative Yersinia isolates should be analyzed for their virulence potential. PMID:9705424

  13. Transgenic alfalfa (Medicago sativa) with increased sucrose phosphate synthase activity shows enhanced growth when grown under N2-fixing conditions.

    Science.gov (United States)

    Gebril, Sayed; Seger, Mark; Villanueva, Fabiola Muro; Ortega, Jose Luis; Bagga, Suman; Sengupta-Gopalan, Champa

    2015-10-01

    Overexpression of SPS in alfalfa is accompanied by early flowering, increased plant growth and an increase in elemental N and protein content when grown under N2-fixing conditions. Sucrose phosphate synthase (SPS; EC 2.3.1.14) is the key enzyme in the synthesis of sucrose in plants. The outcome of overexpression of SPS in different plants using transgenic approaches has been quite varied, but the general consensus is that increased SPS activity is associated with the production of new sinks and increased sink strength. In legumes, the root nodule is a strong C sink and in this study our objective was to see how increasing SPS activity in a legume would affect nodule number and function. Here we have transformed alfalfa (Medicago sativa, cv. Regen SY), with a maize SPS gene driven by the constitutive CaMV35S promoter. Our results showed that overexpression of SPS in alfalfa, is accompanied by an increase in nodule number and mass and an overall increase in nitrogenase activity at the whole plant level. The nodules exhibited an increase in the level of key enzymes contributing to N assimilation including glutamine synthetase and asparagine synthetase. Moreover, the stems of the transformants showed higher level of the transport amino acids, Asx, indicating increased export of N from the nodules. The transformants exhibited a dramatic increase in growth both of the shoots and roots, and earlier flowering time, leading to increased yields. Moreover, the transformants showed an increase in elemental N and protein content. The overall conclusion is that increased SPS activity improves the N status and plant performance, suggesting that the availability of more C in the form of sucrose enhances N acquisition and assimilation in the nodules.

  14. Pronounced Phenotypic Changes in Transgenic Tobacco Plants Overexpressing Sucrose Synthase May Reveal a Novel Sugar Signaling Pathway

    Science.gov (United States)

    Nguyen, Quynh Anh; Luan, Sheng; Wi, Seung G.; Bae, Hanhong; Lee, Dae-Seok; Bae, Hyeun-Jong

    2016-01-01

    Soluble sugars not only serve as nutrients, but also act as signals for plant growth and development, but how sugar signals are perceived and translated into physiological responses in plants remains unclear. We manipulated sugar levels in transgenic plants by overexpressing sucrose synthase (SuSy), which is a key enzyme believed to have reversible sucrose synthesis and sucrose degradation functions. The ectopically expressed SuSy protein exhibited sucrose-degrading activity, which may change the flux of sucrose demand from photosynthetic to non-photosynthetic cells, and trigger an unknown sucrose signaling pathway that lead to increased sucrose content in the transgenic plants. An experiment on the transition from heterotrophic to autotrophic growth demonstrated the existence of a novel sucrose signaling pathway, which stimulated photosynthesis, and enhanced photosynthetic synthesis of sucrose, which was the direct cause or the sucrose increase. In addition, a light/dark time treatment experiment, using different day length ranges for photosynthesis/respiration showed the carbohydrate pattern within a 24-h day and consolidated the role of sucrose signaling pathway as a way to maintain sucrose demand, and indicated the relationships between increased sucrose and upregulation of genes controlling development of the shoot apical meristem (SAM). As a result, transgenic plants featured a higher biomass and a shorter time required to switch to reproduction compared to those of control plants, indicating altered phylotaxis and more rapid advancement of developmental stages in the transgenic plants. PMID:26793204

  15. Frequency of sucrose exposure on the cariogenicity of a biofilm-caries model

    Science.gov (United States)

    Díaz-Garrido, Natalia; Lozano, Carla; Giacaman, Rodrigo A.

    2016-01-01

    Objective: Although sucrose is considered the most cariogenic carbohydrate in the human diet, the question of how many exposures are needed to induce damage on the hard dental tissues remains unclear. To approach this question, different frequencies of daily sucrose exposure were tested on a relevant biological caries model. Materials and Methods: Biofilms of the Streptococcus mutans were formed on enamel slabs and exposed to cariogenic challenges with 10% sucrose for 5 min at 0, 1, 3, 5, 8, or 10 times per day. After 5 days, biofilms were retrieved to analyze biomass, protein content, viable bacteria, and polysaccharide formation. Enamel demineralization was evaluated by percentage of microhardness loss (percentage surface hardness loss [%SHL]). Results: Biomass, protein content, polysaccharide production, acidogenicity of the biofilm, and %SHL proportionally increased with the number of daily exposures to sucrose (P 0.05). Conclusions: Higher sucrose exposure seems to increase cariogenicity, in a frequency-dependent manner, by the modification of bacterial virulent properties. PMID:27403051

  16. EPR response of sucrose and microcrystalline cellulose to measure high doses of gamma radiation

    International Nuclear Information System (INIS)

    Torijano, E.; Cruz, L.; Gutierrez, G.; Azorin, J.; Aguirre, F.; Cruz Z, E.

    2015-10-01

    Solid dosimeters of sucrose and microcrystalline cellulose (Avicel Ph-102) were prepared, following the same process, in order to compare their EPR response against that of the l-alanine dosimeters considered as reference. All lots of dosimeters were irradiated with gamma radiation in Gamma beam irradiator with 8 kGy/h of the Nuclear Sciences Institute of UNAM. Doses ranged from 1 to 10 kGy respectively. We found that both the response of sucrose as microcrystalline cellulose were linear; however, the response intensity was, on average, twenty times more for sucrose. Comparing this against the EPR response of l-alanine in the range of doses, it was found that the response to sucrose is a third part; and microcrystalline cellulose is a sixtieth, approximately. The results agree with those found in the literature for sucrose, leaving open the possibility of investigating other dosage ranges for cellulose. (Author)

  17. Aroma volatility from aqueous sucrose solutions at low and subzero temperatures.

    Science.gov (United States)

    Covarrubias-Cervantes, Marco; Champion, Dominique; Debeaufort, Frédéric; Voilley, Andrée

    2004-11-17

    The gas-liquid partition coefficients of ethyl acetate and ethyl hexanoate have been measured in water and aqueous sucrose solutions from 25 to -10 degrees C by dynamic headspace. Experiments were carried out on sucrose solutions at temperatures where no ice formation was possible. Results showed that when sucrose concentration increased, aroma volatility increased except for ethyl hexanoate and in the highest sucrose concentration solution (57.5%). A quasi-linear temperature decrease on aroma volatility was observed in sucrose solutions from 25 to around 4 and 0 degrees C. Then, from 0 to -10 degrees C, aroma volatility did not decrease: ethyl acetate volatility remained constant but that of ethyl hexanoate increased. Enthalpy of vaporization and activity coefficients of the aroma compounds were calculated.

  18. Effectiveness of sucrose during the frozen storage of arazá (Eugenia stipitata Mc. Vaugh pulp

    Directory of Open Access Journals (Sweden)

    Kelly Johanna Silva-Bustos

    2011-12-01

    Full Text Available The effects of sucrose on the quality of frozen arazá pulp were investigated. Five levels of sucrose (0, 5, 10, 20, and 30% were evaluated in combination with freezing at low speed, storage during one month, and thawing at two different speeds. Sensory quality and water loss after centrifugation (WLAC were evaluated in the samples. Before freezing sucrose addition (5-30% to the pulp did not affect the sensory quality of the samples, but a negative effect on WLAC at 5-10% sucrose was observed. Furthermore, addition of 20-30% sucrose to arazá pulp, in combination with low speed-freezing, frozen storage, and low-speed-thawing, can be a useful technique to preserve the texture of arazá pulp. The described treatment gave results comparable to those obtained for the fresh pulp and much better than those obtained when freezing was done at high speed

  19. [14C]-Sucrose uptake by guard cell protoplasts of pisum sativum, argenteum mutant

    International Nuclear Information System (INIS)

    Rohrig, K.; Raschke, K.

    1991-01-01

    Guard cells rely on import for their supply with reduced carbon. The authors tested by silicone oil centrifugation the ability of guard cell protoplasts to accumulated [ 14 C]-sucrose. Uptake rates were corrected after measurement of 14 C-sorbitol and 3 H 2 O spaces. Sucrose uptake followed biphasic kinetics, with a high-affinity component below 1 mM external sucrose (apparent K m 0.8 mM at 25C) and a low-affinity nonsaturable component above. Uptake depended on pH (optimum at pH 5.0). Variations in the concentrations of external KCl, CCCP, and valinomycin indicated that about one-half of the sucrose uptake rate could be related to an electrochemical gradient across the plasmalemma. Total uptake rates measured at 5 mM external sucrose seem to be sufficient to replenish emptied plastids with starch within a few hours

  20. A sucrose-rich diet induces mutations in the rat colon

    DEFF Research Database (Denmark)

    Dragsted, Lars O.; Daneshvar, Bahram; Vogel, Ulla

    2002-01-01

    A sucrose-rich diet has repeatedly been observed to have cocarcinogenic actions in the colon and liver of rats and to increase the number of aberrant crypt foci in rat colon. To investigate whether sucrose-rich diets might directly increase the genotoxic response in the rat colon or liver, we have...... added sucrose to the diet of Big Blue rats, a strain of Fischer rats carrying 40 copies of the lambda-phage on chromosome 4. Dietary sucrose was provided to the rats for 3 weeks at four dose levels including the background level in the purified diet [3.4% (control), 6.9%, 13.8%, or 34.5%] without...... of a sucrose-rich diet. No significant increase in mutations was observed in the liver. To seek an explanation for this finding, a variety of parameters were examined representing different mechanisms, including increased oxidative stress, changes in oxidative defense, effects on DNA repair, or changes...

  1. Possible roles of vacuolar H+-ATPase and mitochondrial function in tolerance to air-drying stress revealed by genome-wide screening of Saccharomyces cerevisiae deletion strains.

    Science.gov (United States)

    Shima, Jun; Ando, Akira; Takagi, Hiroshi

    2008-03-01

    Yeasts used in bread making are exposed to air-drying stress during dried yeast production processes. To clarify the genes required for air-drying tolerance, we performed genome-wide screening using the complete deletion strain collection of diploid Saccharomyces cerevisiae. The screening identified 278 gene deletions responsible for air-drying sensitivity. These genes were classified based on their cellular function and on the localization of their gene products. The results showed that the genes required for air-drying tolerance were frequently involved in mitochondrial functions and in connection with vacuolar H(+)-ATPase, which plays a role in vacuolar acidification. To determine the role of vacuolar acidification in air-drying stress tolerance, we monitored intracellular pH. The results showed that intracellular acidification was induced during air-drying and that this acidification was amplified in a deletion mutant of the VMA2 gene encoding a component of vacuolar H(+)-ATPase, suggesting that vacuolar H(+)-ATPase helps maintain intracellular pH homeostasis, which is affected by air-drying stress. To determine the effects of air-drying stress on mitochondria, we analysed the mitochondrial membrane potential under air-drying stress conditions using MitoTracker. The results showed that mitochondria were extremely sensitive to air-drying stress, suggesting that a mitochondrial function is required for tolerance to air-drying stress. We also analysed the correlation between oxidative-stress sensitivity and air-drying-stress sensitivity. The results suggested that oxidative stress is a critical determinant of sensitivity to air-drying stress, although ROS-scavenging systems are not necessary for air-drying stress tolerance. (c) 2008 John Wiley & Sons, Ltd.

  2. Diurnal fluctuations in cotton leaf carbon export, carbohydrate content, and sucrose synthesizing enzymes.

    Science.gov (United States)

    Hendrix, D L; Huber, S C

    1986-06-01

    In fully expanded leaves of greenhouse-grown cotton (Gossypium hirsutum L., cv Coker 100) plants, carbon export, starch accumulation rate, and carbon exchange rate exhibited different behavior during the light period. Starch accumulation rates were relatively constant during the light period, whereas carbon export rate was greater in the afternoon than in the morning even though the carbon exchange rate peaked about noon. Sucrose levels increased throughout the light period and dropped sharply with the onset of darkness; hexose levels were relatively constant except for a slight peak in the early morning. Sucrose synthase, usually thought to be a degradative enzyme, was found in unusually high activities in cotton leaf. Both sucrose synthase and sucrose phosphate synthetase activities were found to fluctuate diurnally in cotton leaves but with different rhythms. Diurnal fluctuations in the rate of sucrose export were generally aligned with sucrose phosphate synthase activity during the light period but not with sucrose synthase activity; neither enzyme activity correlated with carbon export during the dark. Cotton leaf sucrose phosphate synthase activity was sufficient to account for the observed carbon export rates; there is no need to invoke sucrose synthase as a synthetic enzyme in mature cotton leaves. During the dark a significant correlation was found between starch degradation rate and leaf carbon export. These results indicate that carbon partitioning in cotton leaf is somewhat independent of the carbon exchange rate and that leaf carbon export rate may be linked to sucrose formation and content during the light period and to starch breakdown in the dark.

  3. Effect of Sucrose and Growth Regulator’s Level on Ginger Micropropagation

    Directory of Open Access Journals (Sweden)

    Resham Babu Amgai

    2017-05-01

    Full Text Available Ginger is most important cash crop of the hilly region of Nepal. However, availability of disease free planting material (rhizome is the major problem faced by Nepalese farmers. Tissue culture is the only option to produce disease free rhizome of ginger. Suitable culture media combination is most important for the production of planting material in ginger through tissue culture. Therefore, effect of different level of sucrose and growth regulators on micro-propagation of ginger was studied using local collection ‘Kaski Local’. Early stage bud was used as explant. MS basal media with different level of sucrose and growth regulators was used as tissue culture media. 30 g/L sucrose, 30 g/L sucrose+5mg/L BA, 30 g/L sucrose+5 mg/L BA+0.5 mg/L NAA, 60 g/L sucrose+5mg/L BA, 60 g/L sucrose+5 mg/L BA+0.5mg/L NAA, 90 g/L sucrose+5 mg/L BA was used in this study. The explants were surface sterilized, cultured and incubated at 25±2°C, 90-95% relative humidity and 14:10 hours light:dark photoperiod for 8 weeks. Increased level of the sucrose increased the rhizome weight, however, addition of NAA produced more positive effect for this. MS basal media with 60 g/L sucrose+5 mg/L BA+0.5 mg/L NAA produced higher rhizome weight.

  4. The catalytic effect of honey on formation of reducing sugars during sucrose hydrolysis

    Directory of Open Access Journals (Sweden)

    Radovanović Mirjana N.

    2017-01-01

    Full Text Available In commercial apiculture, beekepers usually remove honey from hives and replenish food reserves with sugar syrup. When honeybees use sugar syrup (sucrose solution, they break down sucrose into glucose and fructose. These processes exhaust and weaken bees. In order to prevent bee exhaustion resulting from this processing, bees should preferably be supplied with ready made food before winter, i.e., with syrup in which sucrose has already been inverted. Feeding with inverted syrups is the most popular way of honeybee feeding. Beekeepers usually prepare inverted syrups by adding a weak organic acid (citric, oxalic, acetic or lactic acid to sucrose solution at elevated temperatures. Inverted syrup production under uncontrolled pH, temperature and time conditions can cause the formation of 5-hydroxymethyl-2-furaldehyde (HMF, a compound harmful to bees. High quality inverted syrup can be obtained through the hydrolytic decomposition of sucrose by the enzyme invertase. Due to its invertase content, honey can be used as a biocatalyst for sucrose inversion. Invertase activity depends on the type, method and time of honey storage. This study evaluates the catalytic effect of acacia honey on formation of reducing sugars during hydrolysis of 50 wt.% sucrose solution. The ratio of reducing sugars and sucrose at 40°C, after 5 days of hydrolysis at a concentration of honey and 10 wt.% was 0.30 g reducing sugars/g of sucrose. The highest content of reducing sugars was achieved at a temperature of 35°C, after 48 h of invertion. In all samples of hydrolysates obtained at different temperatures (35–65°C, HMF was detected at concentrations of less than 4.32 mg kg–1. A high degree of negative correlation (coefficient of linearity –0.94 was established between parameters of volumetric and polarimetric measurements during the hydrolysis of sucrose. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 46010

  5. Tonoplast- and plasma membrane-localized aquaporin-family transporters in blue hydrangea sepals of aluminum hyperaccumulating plant.

    Directory of Open Access Journals (Sweden)

    Takashi Negishi

    Full Text Available Hydrangea (Hydrangea macrophylla is tolerant of acidic soils in which toxicity generally arises from the presence of the soluble aluminum (Al ion. When hydrangea is cultivated in acidic soil, its resulting blue sepal color is caused by the Al complex formation of anthocyanin. The concentration of vacuolar Al in blue sepal cells can reach levels in excess of approximately 15 mM, suggesting the existence of an Al-transport and/or storage system. However, until now, no Al transporter has been identified in Al hyperaccumulating plants, animals or microorganisms. To identify the transporter being responsible for Al hyperaccumulation, we prepared a cDNA library from blue sepals according to the sepal maturation stage, and then selected candidate genes using a microarray analysis and an in silico study. Here, we identified the vacuolar and plasma membrane-localized Al transporters genes vacuolar Al transporter (VALT and plasma membrane Al transporter 1 (PALT1, respectively, which are both members of the aquaporin family. The localization of each protein was confirmed by the transient co-expression of the genes. Reverse transcription-PCR and immunoblotting results indicated that VALT and PALT1 are highly expressed in sepal tissue. The overexpression of VALT and PALT1 in Arabidopsis thaliana conferred Al-tolerance and Al-sensitivity, respectively.

  6. Crystal Nucleation and Crystal Growth and Mass Transfer in Internally Mixed Sucrose/NaNO3 Particles.

    Science.gov (United States)

    Ji, Zhi-Ru; Zhang, Yun; Pang, Shu-Feng; Zhang, Yun-Hong

    2017-10-19

    Secondary organic aerosols (SOA) can exist in a glassy or semisolid state under low relative humidity (RH) conditions, in which the particles show nonequilibrium kinetic characteristics with changing ambient RH. Here, we selected internally mixed sucrose/NaNO 3 droplets with organic to inorganic molar ratios (OIRs) of 1:8, 1:4, 1:2, and 1:1 as a proxy for multicomponent ambient aerosols to study crystal nucleation and growth processes and water transport under a highly viscous state with the combination of an RH-controlling system and a vacuum Fourier transform infrared (FTIR) spectrometer. The initial efflorescence RH (ERH) of NaNO 3 decreased from ∼45% for pure NaNO 3 droplets to ∼38.6 and ∼37.9% for the 1:8 and 1:4 sucrose/NaNO 3 droplets, respectively, while no crystallization of NaNO 3 occurred for the 1:2 and 1:1 droplets in the whole RH range. Thus, the addition of sucrose delayed the ERH and even completely inhibited nucleation of NaNO 3 in the mixed droplets. In addition, the crystal growth of NaNO 3 was suppressed in the 1:4 and 1:8 droplets most likely due to the slow diffusion of Na + and NO 3 - ions at low RH. Water uptake/release of sucrose/NaNO 3 particles quickly arrived at equilibrium at high RH, while the hygroscopic process was kinetically controlled under low RH. The half-time ratio between the liquid water content and the RH was used to describe the mass transfer behavior. For the 1:1 droplets, no mass limitation was observed with the ratio approaching to 1 when the RH was higher than 53%. The ratio increased 1 order of magnitude under an ultraviscous state with RH ranging from 53 to 15% and increased a further 1 order of magnitude at RH < 15% under a glassy state.

  7. RNAi-directed downregulation of vacuolar H(+ -ATPase subunit a results in enhanced stomatal aperture and density in rice.

    Directory of Open Access Journals (Sweden)

    Huiying Zhang

    Full Text Available Stomatal movement plays a key role in plant development and response to drought and salt stress by regulating gas exchange and water loss. A number of genes have been demonstrated to be involved in the regulation of this process. Using inverse genetics approach, we characterized the function of a rice (Oryza sativa L. vacuolar H(+-ATPase subunit A (OsVHA-A gene in stomatal conductance regulation and physiological response to salt and osmotic stress. OsVHA-A was constitutively expressed in different rice tissues, and the fusion protein of GFP-OsVHA-A was exclusively targeted to tonoplast when transiently expressed in the onion epidermal cells. Heterologous expression of OsVHA-A was able to rescue the yeast mutant vma1Δ (lacking subunit A activity phenotype, suggesting that it partially restores the activity of V-ATPase. Meanwhile, RNAi-directed knockdown of OsVHA-A led to a reduction of vacuolar H(+-ATPase activity and an enhancement of plasma membrane H(+-ATPase activity, thereby increasing the concentrations of extracellular H(+ and intracellular K(+ and Na(+ under stress conditions. Knockdown of OsVHA-A also resulted in the upregulation of PAM3 (plasma membrane H(+-ATPase 3 and downregulation of CAM1 (calmodulin 1, CAM3 (calmodulin 3 and YDA1 (YODA, a MAPKK gene. Altered level of the ion concentration and the gene expression by knockdown of OsVHA-A probably resulted in expanded aperture of stomatal pores and increased stomatal density. In addition, OsVHA-A RNAi plants displayed significant growth inhibition under salt and osmotic stress conditions. Taken together, our results suggest that OsVHA-A takes part in regulating stomatal density and opening via interfering with pH value and ionic equilibrium in guard cells and thereby affects the growth of rice plants.

  8. Sugar transport by maize endosperm suspension cultures

    International Nuclear Information System (INIS)

    Felker, F.C.; Goodwin, J.C.

    1987-01-01

    To determine the mechanism of sugar uptake by suspension cultures derived from developing maize (Zea mays L.) endosperm, incorporation of radioactivity from 14 C-sugars by the tissue in the mid-log phase of growth was examined. Among the sugars tested was l'-deoxy-l'-fluorosucrose (FS), a derivative not hydrolyzed by invertase but recognized by sucrose carriers in other systems. At 40 mM, uptake of label from FS was 23% of that from sucrose, while uptake of label from L-glucose (used as a control for medium carry-over and adsorption) was 16% of that from sucrose. Uptake of label from sucrose did not increase at concentrations above 50 mM, possibly due to a rate-limiting requirement for extracellular hydrolysis. Kinetic analysis revealed both saturable and linear components of uptake for glucose and fructose. The rate of fructose uptake exceeded that of glucose at all concentrations. Fructose uptake at 20 mM was inhibited by NaN 3 , HgCl 2 , dinitrophenol, carbonyl cyanide m-chlorophenylhydrazone, and p-chloromercuribenzenesulfonic acid. Results suggest that sucrose is hydrolyzed prior to uptake, and that fructose is transported preferentially by a carrier sensitive to an external sulfhydryl group inhibitor. Metabolic activity is required for sugar uptake. The specificity of the hexose transporter is currently being investigated

  9. CHEMOENZYMATIC SYNTHESIS OF BIODEGRADABLE POLY(1′-O-VINYLADIPOYL-SUCROSE)

    Institute of Scientific and Technical Information of China (English)

    Des-hui Lu; Qi Wu; Xian-fu Lin

    2002-01-01

    A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymaticallyprepared monomer, 1′-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate inanhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60℃ for 7 days gave VAS (yield 55%) withoutany blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiatorto give poly(1′-O-vinyladipoyl-sucrose) with Mn = 33,000 and Mw = 53,200, Mw/Mn = 1.61. The polymer was biodegradable.After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1′-O-vinyladipoyl-sucrose) to Mn of ca.1080, Mw/Mn = 3.30 (37℃), and Mn of ca. 5200, Mw/Mn = 2.44 (4℃). The polymer containing the sucrose branch would be afunctional material in various application fields.

  10. Family history of alcoholism and the human brain response to oral sucrose.

    Science.gov (United States)

    Eiler, William J A; Dzemidzic, Mario; Soeurt, Christina M; Carron, Claire R; Oberlin, Brandon G; Considine, Robert V; Harezlak, Jaroslaw; Kareken, David A

    2018-01-01

    A heightened hedonic response to sweet tastes has been associated with increased alcohol preference and alcohol consumption in both humans and animals. The principal goal of this study was to examine blood oxygenation level dependent (BOLD) activation to high- and low-concentration sweet solutions in subjects who are either positive (FHP) or negative (FHN) for a family history of alcoholism. Seventy-four non-treatment seeking, community-recruited, healthy volunteers (22.8 ± 1.6 SD years; 43% men) rated a range of sucrose concentrations in a taste test and underwent functional magnetic resonance imaging (fMRI) during oral delivery of water, 0.83 M, and 0.10 M sucrose. Sucrose compared to water produced robust activation in primary gustatory cortex, ventral insula, amygdala, and ventral striatum. FHP subjects displayed greater bilateral amygdala activation than FHN subjects in the low sucrose concentration (0.10 M). In secondary analyses, the right amygdala response to the 0.10 M sucrose was greatest in FHP women. When accounting for group differences in drinks per week, the family history groups remained significantly different in their right amygdala response to 0.10 M sucrose. Our findings suggest that the brain response to oral sucrose differs with a family history of alcoholism, and that this response to a mildly reinforcing primary reward might be an endophenotypic marker of alcoholism risk.

  11. Family history of alcoholism and the human brain response to oral sucrose

    Directory of Open Access Journals (Sweden)

    William J.A. Eiler, II

    2018-01-01

    Full Text Available A heightened hedonic response to sweet tastes has been associated with increased alcohol preference and alcohol consumption in both humans and animals. The principal goal of this study was to examine blood oxygenation level dependent (BOLD activation to high- and low-concentration sweet solutions in subjects who are either positive (FHP or negative (FHN for a family history of alcoholism. Seventy-four non-treatment seeking, community-recruited, healthy volunteers (22.8 ± 1.6 SD years; 43% men rated a range of sucrose concentrations in a taste test and underwent functional magnetic resonance imaging (fMRI during oral delivery of water, 0.83 M, and 0.10 M sucrose. Sucrose compared to water produced robust activation in primary gustatory cortex, ventral insula, amygdala, and ventral striatum. FHP subjects displayed greater bilateral amygdala activation than FHN subjects in the low sucrose concentration (0.10 M. In secondary analyses, the right amygdala response to the 0.10 M sucrose was greatest in FHP women. When accounting for group differences in drinks per week, the family history groups remained significantly different in their right amygdala response to 0.10 M sucrose. Our findings suggest that the brain response to oral sucrose differs with a family history of alcoholism, and that this response to a mildly reinforcing primary reward might be an endophenotypic marker of alcoholism risk.

  12. Physical properties and consumer liking of cookies prepared by replacing sucrose with tagatose.

    Science.gov (United States)

    Taylor, T P; Fasina, O; Bell, L N

    2008-04-01

    The objective of this study was to investigate the suitability of tagatose, a minimally absorbed prebiotic monosaccharide, as a replacement for sucrose in cookies. A sucrose-containing cookie recipe was prepared as the control. Sucrose was replaced with tagatose at various levels ranging from 25% to 100%. Cookies containing fructose were also prepared for comparison due to the structural similarities between tagatose and fructose. The rheological properties of the dough were measured using texture profile analysis. The baked cookies were evaluated for spread, color, and hardness. For tagatose-containing cookies, the extent of likeness was evaluated by 53 untrained panelists using a 9-point hedonic scale. When sucrose was replaced by tagatose, doughs with similar rheological properties to the control resulted. The tagatose-containing cookies were harder and darker with a lower spread than the control. Sensory data indicated that panelists liked the brown color of the 100% tagatose cookies better than the control, but disliked their sweetness. Overall likeness scores of the control and cookies made by replacing half of the sucrose with tagatose were the same. Tagatose appears to be suitable as a partial replacer for sucrose in cookies based on similar dough properties, cookie properties, and likeness scores. Using tagatose to replace sucrose in foods would reduce the amount of metabolizeable sugars in the diet as well as provide the desirable prebiotic effect.

  13. Oral sucrose for heel lance increases adenosine triphosphate use and oxidative stress in preterm neonates.

    Science.gov (United States)

    Asmerom, Yayesh; Slater, Laurel; Boskovic, Danilo S; Bahjri, Khaled; Holden, Megan S; Phillips, Raylene; Deming, Douglas; Ashwal, Stephen; Fayard, Elba; Angeles, Danilyn M

    2013-07-01

    To examine the effects of sucrose on pain and biochemical markers of adenosine triphosphate (ATP) degradation and oxidative stress in preterm neonates experiencing a clinically required heel lance. Preterm neonates that met study criteria (n = 131) were randomized into 3 groups: (1) control; (2) heel lance treated with placebo and non-nutritive sucking; and (3) heel lance treated with sucrose and non-nutritive sucking. Plasma markers of ATP degradation (hypoxanthine, xanthine, and uric acid) and oxidative stress (allantoin) were measured before and after the heel lance. Pain was measured with the Premature Infant Pain Profile. Data were analyzed by the use of repeated-measures ANOVA and Spearman rho. We found significant increases in plasma hypoxanthine and uric acid over time in neonates who received sucrose. We also found a significant negative correlation between pain scores and plasma allantoin concentration in a subgroup of neonates who received sucrose. A single dose of oral sucrose, given before heel lance, significantly increased ATP use and oxidative stress in premature neonates. Because neonates are given multiple doses of sucrose per day, randomized trials are needed to examine the effects of repeated sucrose administration on ATP degradation, oxidative stress, and cell injury. Copyright © 2013 Mosby, Inc. All rights reserved.

  14. Reduced infant response to a routine care procedure after sucrose analgesia.

    Science.gov (United States)

    Taddio, Anna; Shah, Vibhuti; Katz, Joel

    2009-03-01

    Sucrose has analgesic and calming effects in newborns. To date, it is not known whether the beneficial effects extend to caregiving procedures that are performed after painful procedures. Our objective was to determine the effect of sucrose analgesia for procedural pain on infant pain responses during a subsequent caregiving procedure. We conducted a double-blind, randomized, controlled trial. Healthy neonates within 2 strata (normal infants and infants of diabetic mothers) were randomly assigned to a sucrose or placebo water group before all needle procedures after birth. Pain response during a diaper change performed after venipuncture for the newborn screening test was determined by using a validated multidimensional measure, the Premature Infant Pain Profile. The study was conducted between September 15, 2003, and July 27, 2004. Altogether, 412 parents were approached; 263 consented. Twenty-three infants were not assigned, leaving 240 for participation (n = 120 per group), with an equal number in each infant strata. Of those, 186 (78%) completed the study. There were no significant differences in birth characteristics between groups. During diaper change, sucrose-treated infants had lower pain scores than placebo-treated infants. The relative risk of having pain, defined as a Premature Infant Pain Profile score of >/=6, was 0.64 with sucrose compared with placebo. This study demonstrates that when used to manage pain, sucrose reduces the pain response to a subsequent routine caregiving procedure. Therefore, the benefits of sucrose analgesia extend beyond the painful event to other aversive and potentially painful procedures.

  15. Transport and phosphorylation of disaccharides by the ruminal bacterium Streptococcus bovis

    International Nuclear Information System (INIS)

    Martin, S.A.; Russell, J.B.

    1987-01-01

    Toluene-treated cells of Streptococcus bovis JB1 phosphorylated cellobiose, glucose, maltose, and sucrose by the phosphoenolpyruvate-dependent phosphotransferase system. Glucose phosphorylation was constitutive, while all three disaccharide systems were inducible. Competition experiments, indicated that separate phosphotransferases systems existed for glucose, maltose, and sucrose. [ 14 C]maltose transport was inhibited by excess glucose and to a lesser extent by sucrose. [ 14 C]glucose and [ 14 C]sucrose transports were not inhibited by an excess of maltose. Since [ 14 C]maltose phosphorylation in triethanolamine buffer was increased 160-fold as the concentration of P/sub i/ was increased from 0 to 100 mM, a maltose phosphorylase was present, and this activity was inducible. Maltose was also hydrolyzed by an inducible maltase. Glucose 1-phosphate arising from the maltose phosphorylase was metabolized by a constitutive phosphoglucomutase that was specific for α-glucose 1-phosphate. Only sucrose-grown cells possessed sucrose hydrolase activity, and this activity was much lower than the sucrose phosphotransferase system and sucrose-phosphate hydrolase activities

  16. Combined compared to dissociated oral and intestinal sucrose stimuli induce different brain hedonic processes

    Directory of Open Access Journals (Sweden)

    Caroline eClouard

    2014-08-01

    Full Text Available The characterization of brain networks contributing to the processing of oral and/or intestinal sugar signals in a relevant animal model might help to understand the neural mechanisms related to the control of food intake in humans and suggest potential causes for impaired eating behaviors. This study aimed at comparing the brain responses triggered by oral and/or intestinal sucrose sensing in pigs. Seven animals underwent brain single photon emission computed tomography (99mTc-HMPAO further to oral stimulation with neutral or sucrose artificial saliva paired with saline or sucrose infusion in the duodenum, the proximal part of the intestine. Oral and/or duodenal sucrose sensing induced differential cerebral blood flow (CBF changes in brain regions known to be involved in memory, reward processes and hedonic (i.e. pleasure evaluation of sensory stimuli, including the dorsal striatum, prefrontal cortex, cingulate cortex, insular cortex, hippocampus and parahippocampal cortex. Sucrose duodenal infusion only and combined sucrose stimulation induced similar activity patterns in the putamen, ventral anterior cingulate cortex and hippocampus. Some brain deactivations in the prefrontal and insular cortices were only detected in the presence of oral sucrose stimulation. Finally, activation of the right insular cortex was only induced by combined oral and duodenal sucrose stimulation, while specific activity patterns were detected in the hippocampus and parahippocampal cortex with oral sucrose dissociated from caloric load. This study sheds new light on the brain hedonic responses to sugar and has potential implications to unravel the neuropsychological mechanisms underlying food pleasure and motivation.

  17. Glycaemic, uricaemic and blood pressure response to beverages with partial fructose replacement of sucrose.

    Science.gov (United States)

    Rodrigues, Natasha; Peng, Mei; Oey, Indrawati; Venn, Bernard Joseph

    2018-03-20

    The European Food Safety Authority approved a health claim (ID558) relating to lowered postprandial glycaemia when fructose replaces 30% of sucrose in foods and beverages. We assessed the effects of partial replacement of sucrose with fructose on serum glucose, uric acid and blood pressure. A randomised, crossover, double blind trial of 12 normoglycaemic participants consuming beverages containing 50 g blends of fructose and sucrose in proportions; 67% sucrose/33% fructose (67%S:33%F); 50% each (50%S:50%F) and 33%S:67%F; a 100% sucrose reference beverage was tested twice. Serum glucose and uric acid concentrations were measured at 0, 15, 30, 45, 60, 90 and 120 min and incremental area-under-the-curve (iAUC) calculated. The geometric mean (95% CI) glycaemic iAUC following the 100% sucrose, 67%S:33%F, 50%S:50%F and 33%S:67%F blended beverages were 96 (63,145), 71 (46,109), 60 (39, 93) and 39 (12, 86) mmol/L min, respectively. At 33% fructose replacement, the proportionally lower iAUC of -28.5% (95% CI: -62.1, 5.2) mmol/L min was not different to sucrose alone. The response was lowered by fructose replacement of 50 and 67% and overall there was an inverse association (p beverages were 1320 (393, 2248), 3062 (1553, 4570), 3646 (2446, 4847), 3623 (2020, 5226) µmol/L min. Uric acid concentration was raised by all fructose-containing beverages with 33% fructose replacement causing an increase of 1741 (95% CI: 655, 2829) µmol/L min compared with sucrose alone. Blood pressure was not different among beverages. Reduced postprandial glycaemia was achieved by the substitution of sucrose with fructose although elevated uricaemic responses should be cautioned.

  18. Chronic high-sucrose diet increases fibroblast growth factor 21 production and energy expenditure in mice.

    Science.gov (United States)

    Maekawa, Ryuya; Seino, Yusuke; Ogata, Hidetada; Murase, Masatoshi; Iida, Atsushi; Hosokawa, Kaori; Joo, Erina; Harada, Norio; Tsunekawa, Shin; Hamada, Yoji; Oiso, Yutaka; Inagaki, Nobuya; Hayashi, Yoshitaka; Arima, Hiroshi

    2017-11-01

    Excess carbohydrate intake causes obesity in humans. On the other hand, acute administration of fructose, glucose or sucrose in experimental animals has been shown to increase the plasma concentration of anti-obesity hormones such as glucagon-like peptide 1 (GLP-1) and Fibroblast growth factor 21 (FGF21), which contribute to reducing body weight. However, the secretion and action of GLP-1 and FGF21 in mice chronically fed a high-sucrose diet has not been investigated. To address the role of anti-obesity hormones in response to increased sucrose intake, we analyzed mice fed a high-sucrose diet, a high-starch diet or a normal diet for 15 weeks. Mice fed a high-sucrose diet showed resistance to body weight gain, in comparison with mice fed a high-starch diet or control diet, due to increased energy expenditure. Plasma FGF21 levels were highest among the three groups in mice fed a high-sucrose diet, whereas no significant difference in GLP-1 levels was observed. Expression levels of uncoupling protein 1 (UCP-1), FGF receptor 1c (FGFR1c) and β-klotho (KLB) mRNA in brown adipose tissue were significantly increased in high sucrose-fed mice, suggesting increases in FGF21 sensitivity and energy expenditure. Expression of carbohydrate responsive element binding protein (ChREBP) mRNA in liver and brown adipose tissue was also increased in high sucrose-fed mice. These results indicate that FGF21 production in liver and brown adipose tissue is increased in high-sucrose diet and participates in resistance to weight gain. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Feasibility study of sucrose and fat replacement using inulin and rebaudioside A in cake formulations.

    Science.gov (United States)

    Majzoobi, Mahsa; Mohammadi, Mahshid; Mesbahi, Gholamreza; Farahnaky, Asgar

    2018-02-20

    Cake is a popular food around the world, however, it is considered as unhealthy due to its high fat and sucrose content. To satisfy customers' demand for a low fat and sucrose cake, in this research both sucrose and fat content of the cake were reduced by using rebaudioside A (Reb A; as a natural sucrose replacer) and inulin (as a natural fat replacer) at 0%, 25%, 50%, 75%, and 100%. The water content of different formulation was adjusted to obtain a constant batter viscosity similar to the control (3,757 cP). By reducing sucrose and fat content up to 50%, water activity increased and the cakes became more asymmetrical. However, other physical properties including baking weight loss, height, volume, crust color, and texture were similar to those of the control. Higher levels of replacement (75% and 100%) resulted in remarkable loss of different quality attributes. These samples showed higher water activity and baking loss, lower volume, harder texture, darker color, and highly asymmetrical shape. Thus, successful reduction of both fat and sucrose in cakes is possible by using inulin and Reb A at replacement levels no more than 50%. Customers' demand for healthy and yet tasty and high-quality foods is increasing around the world. Therefore, finding applicable and safe methods to produce such products is of great interest in the food manufacturing to satisfy customers. Health conscious customers avoid consumption of cakes because it contains high sucrose and fat content. Many studies have been performed to reduce either fat or sucrose content, while a few studies are available to show the reduction of both fat and sucrose in the same product. This study indicates the results of an applicable method to reduce fat and sucrose content of cakes simultaneously. Using rebaudioside A (as a natural sucrose replacer) and inulin (as a natural fat replacer) up to 50% of sucrose and fat content of cakes were reduced and the resulting cake had very similar physical properties to

  20. Forced-flow bioreactor for sucrose inversion using ceramic membrane activated by silanization.

    Science.gov (United States)

    Nakajima, M; Watanabe, A; Jimbo, N; Nishizawa, K; Nakao, S

    1989-02-20

    A forced-flow enzyme membrane reactor system for sucrose inversion was investigated using three ceramic membranes having different pore sizes. Invertase was immobilized chemically to the inner surface of a ceramic membrane activated by a silane-glutaraldehyde technique. With the cross-flow filtration of sucrose solution, the reaction rate was a function of the permeate flux, easily controlled by pressure. Using 0.5 microm support pore size of membrane, the volumetric productivity obtained was 10 times higher than that in a reported immobilized enzyme column reactor, with a short residence time of 5 s and 100% conversion of the sucrose inversion.

  1. Consumption of baked nuts or seeds reduces dental plaque acidogenicity after sucrose challenge.

    Science.gov (United States)

    Wang, Xiaoling; Cheng, Chuoyue; Ge, Chunling; Wang, Bing; Gan, Ye-Hua

    2016-06-01

    To assess the acidogenic potential of eight different types of baked nuts or seeds eaten alone and after a sucrose challenge using in-dwelling electrode telemetry. Six participants wearing a mandibular partial prosthesis incorporated with a miniature glass pH electrode were enrolled. The plaque pH was measured after 5 or 6 days of plaque accumulation. To establish a control, the subjects were instructed to rinse with sucrose, without any subsequent treatment, at the first visit. At each subsequent test visit, the subjects were asked to chew sugar free xylitol gum or consume 10 g of baked (180 degrees C, 5 minutes) peanuts, walnuts, pistachios, cashews, almonds, sunflower seeds, pumpkin seeds, or watermelon seeds alone and 10 minutes after a sucrose rinse. The minimum plaque pH value and area of plaque pH curve under 5.7 (AUC5.7) during and after nut/seed consumption or gum chewing alone, the plaque pH value at 10 minutes after the sucrose rinse, the time required for the pH to return to >5.7 and AUC5.7 after the sucrose rinse with or without nut/seed consumption or gum chewing were calculated from the telemetric curves. The sucrose rinse induced a rapid decrease in the plaque pH to 4.32 +/- 0.17 at 10 minutes; this value remained below 5.7 for the measurement period. The AUC5.7 values were 34.58 +/- 7.27 and 63.55 +/- 15.17 for 40 and 60 minutes after the sucrose challenge, respectively. With the exception of cashews and pumpkin seeds (minimum pH, 5.42 and 5.63 respectively), the nuts or seeds did not decrease the plaque pH to below 5.7 when consumed alone, with the AUC5.7 values during and after consumption (total 40 minutes) ranging from 0.24 to 2.5 (8.44 for cashews), which were significantly lower than those after the sucrose challenge. Furthermore, nut/seed consumption or gum chewing after the sucrose challenge significantly reversed the sucrose-induced decrease in the plaque pH, and the time required for the pH to return to >5.7 and the AUC5.7 values for 60

  2. The apo structure of sucrose hydrolase from Xanthomonas campestris pv. campestris shows an open active-site groove

    DEFF Research Database (Denmark)

    Champion, Elise; Remaud-Simeon, Magali; Skov, Lars Kobberøe

    2009-01-01

    Glycoside hydrolase family 13 (GH-13) mainly contains starch-degrading or starch-modifying enzymes. Sucrose hydrolases utilize sucrose instead of amylose as the primary glucosyl donor. Here, the catalytic properties and X-ray structure of sucrose hydrolase from Xanthomonas campestris pv. campestris...... of GH-13. Comparisons with structures of the highly similar sucrose hydrolase from X. axonopodis pv. glycines most notably showed that residues Arg516 and Asp138, which form a salt bridge in the X. axonopodis sucrose complex and define part of the subsite -1 glucosyl-binding determinants...

  3. Sugar Transporters in Plants: New Insights and Discoveries.

    Science.gov (United States)

    Julius, Benjamin T; Leach, Kristen A; Tran, Thu M; Mertz, Rachel A; Braun, David M

    2017-09-01

    Carbohydrate partitioning is the process of carbon assimilation and distribution from source tissues, such as leaves, to sink tissues, such as stems, roots and seeds. Sucrose, the primary carbohydrate transported long distance in many plant species, is loaded into the phloem and unloaded into distal sink tissues. However, many factors, both genetic and environmental, influence sucrose metabolism and transport. Therefore, understanding the function and regulation of sugar transporters and sucrose metabolic enzymes is key to improving agriculture. In this review, we highlight recent findings that (i) address the path of phloem loading of sucrose in rice and maize leaves; (ii) discuss the phloem unloading pathways in stems and roots and the sugar transporters putatively involved; (iii) describe how heat and drought stress impact carbohydrate partitioning and phloem transport; (iv) shed light on how plant pathogens hijack sugar transporters to obtain carbohydrates for pathogen survival, and how the plant employs sugar transporters to defend against pathogens; and (v) discuss novel roles for sugar transporters in plant biology. These exciting discoveries and insights provide valuable knowledge that will ultimately help mitigate the impending societal challenges due to global climate change and a growing population by improving crop yield and enhancing renewable energy production. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Sucrose in Cyanobacteria: From a Salt-Response Molecule to Play a Key Role in Nitrogen Fixation

    Directory of Open Access Journals (Sweden)

    María A. Kolman

    2015-01-01

    Full Text Available In the biosphere, sucrose is mainly synthesized in oxygenic photosynthetic organisms, such as cyanobacteria, green algae and land plants, as part of the carbon dioxide assimilation pathway. Even though its central position in the functional biology of plants is well documented, much less is known about the role of sucrose in cyanobacteria. In those prokaryotes, sucrose accumulation has been associated with salt acclimation, and considered as a compatible solute in low-salt tolerant strains. In the last years, functional characterizations of sucrose metabolizing enzymes, metabolic control analysis, cellular localization of gene expressions, and reverse genetic experiments have revealed that sucrose metabolism is crucial in the diazotrophic growth of heterocystic strains, and besides, that it can be connected to glycogen synthesis. This article briefly summarizes the current state of knowledge of sucrose physiological functions in modern cyanobacteria and how they might have evolved taking into account the phylogenetic analyses of sucrose enzymes.

  5. Starch and sucrose synthesis in Phaseolus vulgaris as affected by light, CO2, and abscisic acid

    International Nuclear Information System (INIS)

    Sharkey, T.D.; Berry, J.A.; Raschke, K.

    1985-01-01

    Phaseolus vulgaris L. leaves were subjected to various light, CO 2 , and O 2 levels and abscisic acid, then given a 10 minute pulse of 14 CO 2 followed by a 5 minute chase with unlabeled CO 2 . After the chase period, very little label remained in the ionic fractions except at low CO 2 partial pressure. Most label was found in the neutral, alcohol soluble fraction or in the insoluble fraction digestable by amyloglucosidase. Sucrose formation was linearly related to assimilation rate. Starch formation increased linearly with assimilation rate, but did not occur if the assimilation rate was below 4 micromoles per square meter per second. Neither abscisic acid, nor high CO 2 in combination with low O 2 caused significant perturbations of the sucrose/starch formation ratio. These studies indicate that the pathways for starch and sucrose synthesis both are controlled by the rate of net CO 2 assimilation, with sucrose the preferred product at very low assimilation rates

  6. Production of Viscous Dextran-Containing Whey-Sucrose Broths by Leuconostoc mesenteroides ATCC 14935

    OpenAIRE

    Schwartz, Robert D.; Bodie, Elizabeth A.

    1984-01-01

    Viscous broths were produced by growing Leuconostoc mesenteroides on a medium containing whey supplemented with sucrose. When combined with similarly produced xanthan-containing broths, a synergistic increase in viscosity was observed.

  7. The effect of nicotine pre-exposure on demand for cocaine and sucrose in male rats.

    Science.gov (United States)

    Schwartz, Lindsay P; Kearns, David N; Silberberg, Alan

    2018-06-01

    The aim of the present study was to determine how nicotine pre-exposure affects the elasticity of demand for intravenous cocaine and for sucrose pellets in adult male rats. In Experiment 1, demand for cocaine was assessed in rats that had nicotine in their drinking water. Nicotine pre-exposure significantly decreased rats' willingness to defend cocaine consumption as the price (measured as the number of responses per cocaine infusion) increased compared with a control group with no nicotine pre-exposure. That is, nicotine increased the elasticity of demand for cocaine infusions. Experiment 2 repeated the first experiment, but with rats working for sucrose pellets instead of cocaine. Nicotine pre-exposure had no effect on the elasticity of demand for sucrose. This pattern of results suggests that nicotine pre-exposure can reduce the reinforcing effects of cocaine, but not sucrose, in adult male rats.

  8. Improvement of Fructanohydrolase Production in Aspergillus niger SL-09 by Sucrose Ester

    Directory of Open Access Journals (Sweden)

    Xiang-Yang Ge

    2006-01-01

    Full Text Available The influence of carbon sources, nitrogen sources, and the addition of sucrose ester on fructanohydrolase production was investigated. The enzyme production varied depending on the carbon source. Apart from that, it was found that the enzyme activities formed by Aspergillus niger SL-09 were enhanced dramatically by the addition of sucrose ester S-770 to the medium. The effect of sucrose ester on enzyme production was also studied on molecular level, and it was confirmed that the transcription was activated by the addition of sucrose ester to the medium. The response surface methodology (RSM was used to optimize the composition for the production of fructanohydrolase, and the enzyme activities were enhanced more than 7-fold than those obtained in the basal medium.

  9. Diverse Exopolysaccharide Producing Bacteria Isolated from Milled Sugarcane: Implications for Cane Spoilage and Sucrose Yield.

    Directory of Open Access Journals (Sweden)

    Stanton Hector

    Full Text Available Bacterial deterioration of sugarcane during harvesting and processing is correlated with significant loss of sucrose yield and the accumulation of bacterial polysaccharides. Dextran, a homoglucan produced by Leuconostoc mesenteroides, has been cited as the primary polysaccharide associated with sugarcane deterioration. A culture-based approach was used to isolate extracellular polysaccharide (EPS producing bacterial strains from milled sugarcane stalks. Ribosomal RNA sequencing analysis grouped 25 isolates into 4 genera. This study identified 2 bacterial genera not previously associated with EPS production or sucrose degradation. All isolates produced polysaccharide when grown in the presence of sucrose. Monosaccharide analysis of purified polymers by Gas Chromatography revealed 17 EPSs consisting solely of glucose (homoglucans, while the remainder contained traces of mannose or fructose. Dextranase treatment of polysaccharides yielded full digestion profiles for only 11 extracts. Incomplete hydrolysis profiles of the remaining polysaccharides suggest the release of longer oligosaccharides which may interfere with sucrose crystal formation.

  10. Minimization of sucrose losses in sugar industry by pH and temperature optimization

    International Nuclear Information System (INIS)

    Panpae, Kornvalai; Jaturonrusmee, Wasna; Mingvanish, Withawat; Santudrob, Kittisak; Triphanpitak, Siriphan

    2008-01-01

    Invert sugar has several disadvantage properties that play an important role in many food applications. It has a high affinity for water and is the cause of making products retain moisture. Invert sugar also affects the carmelization process, producing a browning effect. In this study, the possibility of minimization of sucrose inversion during the industrial production of sugar cane was investigated by the variation of the important parameters, i.e. temperature and pH of sugar cane juice for each of samples. The amounts of sucrose and reducing sugar alerting during the sucrose inversion process were determined by the values of % Pol and % reducing sugar (% RS), respectively. Starting with the study of temperature and pH effects of the sucrose solution with the concentration of 16 Brix, used as a sample model, it was found that no change in amounts of reducing sugar and sucrose was observed at room temperature (34 degree Celsius) in the pH range of 5-11. At pH 3, the amounts of reducing sugar increased and the amount of sucrose decreased as the time increased. These indicated that the process of sucrose inversion should better occur in more acidic solutions. Compared to the room temperature, it was found that the increment of temperature led to enhance the process of sucrose inversion. This was depicted by higher values of % RS and lower value of % Pol as the temperatures were elevated. The experiments were also done with real sugar cane juice, i.e. first, last, and mixed juice. The tendency of changes of the amounts of reducing sugar and sucrose in sugar cane samples by varying temperature and pH were found to resemble to those for the sample model. The increment of temperatures have also affected on a reduction of amounts of sucrose in each sugar cane juice. In addition, it could be concluded that the acidity of the solution affects sucrose easier to be broken down to glucose and fructose molecules. (author)

  11. Heat capacity and transition behavior of sucrose by standard, fast scanning and temperature-modulated calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Magoń, A. [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland); Wurm, A.; Schick, C. [Department of Physics, University of Rostock, 18057 Rostock (Germany); Pangloli, Ph.; Zivanovic, S. [Department of Food Science and Technology, University of Tennessee, Knoxville, TN 37996 (United States); Skotnicki, M. [Department of Pharmaceutical Technology, Poznan University of Medical Sciences, 60-780 Poznań (Poland); Pyda, M., E-mail: mpyda@utk.edu [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland)

    2014-08-10

    Highlights: • Experimental, apparent heat capacity of sucrose was investigated by advanced thermal analysis. • Vibrational heat capacity of solid state was linked with a low temperature experimental heat capacity of sucrose. • Equilibrium melting parameters of sucrose were determined. • Decomposition, superheating of crystalline sucrose during melting process were presented. • TGA, DSC, TMDSC, and FSC are useful tools for characterization of sucrose. - Abstract: The heat capacity (C{sub p}) of crystalline and amorphous sucrose was determined using standard and quasi-isothermal temperature modulated differential scanning calorimetry. The results were combined with the published data determined by adiabatic calorimetry, and the C{sub p} values are now reported for the wide 5–600 K range. The experimental C{sub p} of solid sucrose at 5–300 K was used to calculate the vibrational, solid C{sub p} based on the vibrational molecular motions. The calculated solid and liquid C{sub p} together with the transition parameters for equilibrium conditions were used as references for detailed quantitative thermal analysis of crystalline and amorphous sucrose. Melting temperature (T{sub m}) of the crystalline sucrose was identified in a broad 442–465 K range with a heat of fusion of 40–46 J/mol determined at heating rates 0.5–20 K/min, respectively. The equilibrium T{sub m} and heat of fusion of crystalline sucrose were estimated at zero heating rate as T{sup o}{sub m} = 424.4 K and ΔH{sup o}{sub f} = 32 kJ/mol, respectively. The glass transition temperature (T{sub g}) of amorphous sucrose was at 331 K with a change in C{sub p} of 267 J/(mol K) as it was estimated from reversing heat capacity by quasi-isothermal TMDSC on cooling. At heating rates less than 30 K/min, thermal decomposition occurred during melting, while at extreme rate of 1000 K/s, degradation was not observed. Data obtained by fast scanning calorimetry (FSC) at 1000 K/s, showed that T{sub m} was

  12. Dissecting genomic hotspots underlying seed protein, oil, and sucrose content in an interspecific mapping population of soybean using high-density linkage mapping.

    Science.gov (United States)

    Patil, Gunvant; Vuong, Tri D; Kale, Sandip; Valliyodan, Babu; Deshmukh, Rupesh; Zhu, Chengsong; Wu, Xiaolei; Bai, Yonghe; Yungbluth, Dennis; Lu, Fang; Kumpatla, Siva; Grover Shannon, J; Varshney, Rajeev K; Nguyen, Henry T

    2018-04-04

    The cultivated [Glycine max (L) Merr.] and wild [Glycine soja Siebold & Zucc.] soybean species comprise wide variation in seed composition traits. Compared to wild soybean, cultivated soybean contains low protein, high oil and high sucrose. In this study, an inter-specific population was derived from a cross between G. max (Williams 82) and G. soja (PI 483460B). This recombinant inbred line (RIL) population of 188 lines was sequenced at 0.3x depth. Based on 91,342 single nucleotide polymorphisms (SNPs), recombination events in RILs were defined, and a high-resolution bin map was developed (4,070 bins). In addition to bin mapping, QTL analysis for protein, oil and sucrose was performed using 3,343 polymorphic SNPs (3K-SNP), derived from Illumina Infinium BeadChip sequencing platform. The QTL regions from both platforms were compared and a significant concordance was observed between bin and 3K-SNP markers. Importantly, the bin map derived from next generation sequencing technology enhanced mapping resolution (from 1325 Kb to 50 Kb). A total of 5, 9 and 4 QTLs were identified for protein, oil and sucrose content, respectively and some of the QTLs coincided with soybean domestication related genomic loci. The major QTL for protein and oil was mapped on Chr. 20 (qPro_20) and suggested negative correlation between oil and protein. In terms of sucrose content, a novel and major QTL was identified on Chr. 8 (qSuc_08) and harbors putative genes involved in sugar transport. In addition, genome-wide association (GWAS) using 91,342 SNPs confirmed the genomic loci derived from QTL mapping. A QTL based haplotype using whole genome resequencing of 106 diverse soybean lines identified unique allelic variation in wild soybean that could be utilized to widen the genetic base in cultivated soybean. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. A sucrose-derived scaffold for multimerization of bioactive peptides.

    Science.gov (United States)

    Rao, Venkataramanarao; Alleti, Ramesh; Xu, Liping; Tafreshi, Narges K; Morse, David L; Gillies, Robert J; Mash, Eugene A

    2011-11-01

    A spherical molecular scaffold bearing eight terminal alkyne groups was synthesized in one step from sucrose. One or more copies of a tetrapeptide azide, either N(3)(CH(2))(5)(CO)-His-DPhe-Arg-Trp-NH(2) (MSH4) or N(3)(CH(2))(5)(CO)-Trp-Met-Asp-Phe-NH(2) (CCK4), were attached to the scaffold via the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Competitive binding assays using Eu-labeled probes based on the superpotent ligands Ser-Tyr-Ser-Nle-Glu-His-DPhe-Arg-Trp-Gly-Lys-Pro-Val-NH(2) (NDP-α-MSH) and Asp-Tyr-Met-Gly-Trp-Met-Asp-Phe-NH(2) (CCK8) were used to study the interactions of monovalent and multivalent MSH4 and CCK4 constructs with Hek293 cells engineered to overexpress MC4R and CCK2R. All of the monovalent and multivalent MSH4 constructs exhibited binding comparable to that of the parental ligand, suggesting that either the ligand spacing was inappropriate for multivalent binding, or MSH4 is too weak a binder for a second 'anchoring' binding event to occur before the monovalently-bound construct is released from the cell surface. In contrast with this behavior, monovalent CCK4 constructs were significantly less potent than the parental ligand, while multivalent CCK4 constructs were as or more potent than the parental ligand. These results are suggestive of multivalent binding, which may be due to increased residence times for monovalently bound CCK4 constructs on the cell surface relative to MSH4 constructs, the greater residence time being necessary for the establishment of multivalent binding. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Moderate High Fat Diet Increases Sucrose Self-Administration In Young Rats

    OpenAIRE

    Figlewicz, Dianne P.; Jay, Jennifer L.; Acheson, Molly A.; Magrisso, Irwin J.; West, Constance H.; Zavosh, Aryana; Benoit, Stephen C.; Davis, Jon F.

    2012-01-01

    We have previously reported that a moderately high fat diet increases motivation for sucrose in adult rats. In this study, we tested the motivational, neurochemical, and metabolic effects of the high fat diet in male rats transitioning through puberty, during 5-8 weeks of age. We observed that the high fat diet increased motivated responding for sucrose, which was independent of either metabolic changes or changes in catecholamine neurotransmitter metabolites in the nucleus accumbens. However...

  15. Role of plaque in the clearance of salivary sucrose and its influence on salivary ph

    OpenAIRE

    A Kumar; R Hedge; U Dixit

    2011-01-01

    Background: The prevalence of dental caries in children, in India, is higher than many of the industrialized countries. The sugar most commonly associated with dental caries is sucrose, as the microorganisms in the dental plaque have the ability to convert this dietary constituent into various organic acids. Aims and Objectives: This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and to study the effect of the presence of plaque on saliv...

  16. A mouse model for binge-like sucrose overconsumption: Contribution of enhanced motivation for sweetener consumption.

    Science.gov (United States)

    Yasoshima, Yasunobu; Shimura, Tsuyoshi

    2015-01-01

    Behavioral and neural features of binge-like sugar overconsumption have been studied using rat models. However, few mouse models are available to examine the interaction between neural and genetic underpinnings of bingeing. In the present study, we first aim to establish a simple mouse model of binge-like sucrose overconsumption using daytime limited access training in food-restricted male mice. Trained mice received 4-h limited access to both 0.5M sucrose solution and chow for 10 days. Three control groups received (1) 4-h sucrose and 20-h chow access, (2) 20-h sucrose and 4-h, or (3) 20-h chow access, respectively. Only the trained group showed progressively increased sucrose consumption during brief periods of time and developed binge-like excessive behavior. Next, we examined whether the present mouse model mimicked a human feature of binge eating known as "eating when not physically hungry." Trained mice consumed significantly more sucrose or non-caloric sweetener (saccharin) during post-training days even after they nocturnally consumed substantial chow prior to daytime sweetener access. In other trained groups, both a systemic administration of glucose and substantial chow consumption prior to the daytime limited sucrose access failed to reduce binge-like sucrose overconsumption. Our results suggest that even when caloric consumption is not necessarily required, limited access training shapes and triggers binge-like overconsumption of sweetened solution in trained mice. The binge-like behavior in trained mice may be mainly due to enhanced hedonic motivation for the sweetener's taste. The present study suggests that our mouse model for binge-like sugar overconsumption may mimic some human features of binge eating and can be used to investigate the roles of neural and genetic mechanisms in binge-like overconsumption of sweetened substances in the absence of physical hunger. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Preparation of 6,6,1',1',6',6'-hexadeutero sucrose.

    Science.gov (United States)

    Gouy, Marie-Hélène; Danel, Mathieu; Gayral, Maud; Bouchu, Alain; Queneau, Yves

    2007-11-05

    The preparation of 6,6,1',1',6',6'-hexadeutero sucrose is reported. The synthesis is based on a triple oxidation of a protected sucrose 6,1',6'-triol to the corresponding 6,1',6'-tricarboxylic acid or ester, followed by reduction with lithium aluminium deuteride. This triple oxidation could be achieved either using cat. TEMPO-NaOCl (to the acid) or PDC-Ac(2)O-t-BuOH (to the t-butyl carboxylic ester).

  18. Possible consequences of the sucrose replacement by a fructose-glucose syrup

    OpenAIRE

    Judit Süli; Ingrid Hamarová; Anna Sobeková

    2017-01-01

    The fructose-glucose syrup is currently used instead of sucrose in bakery products for economic and technological reasons. The authors investigated the extent to which this change affects the formation of non-enzymatic browning products (Advanced Glycation End - AGE-Products and melanoidins). Formation of these products in model systems - mixtures of various sugars (sucrose, fructose, glucose - concentration 6%) with glycine (concentration 0.7%) or/and lysine (concentration 0.3%), heat-treate...

  19. Sucrose Fermentation by Brazilian Ethanol Production Yeasts in Media Containing Structurally Complex Nitrogen Sources

    OpenAIRE

    Miranda Junior, Messias [UNESP; Batistote, Margareth [UNESP; Cilli, Eduardo Maffud [UNESP; Ernandes, Jose Roberto [UNESP

    2009-01-01

    Four Saccharomyces cerevisiae Brazilian industrial ethanol production strains were grown, under shaken and static conditions, in media containing 22% (w/v) sucrose supplemented with nitrogen sources varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Sucrose fermentations by Brazilian industrial ethanol production yeasts strains were strongly affected by both the structural complexity of the nitrogen source and the availability o...

  20. Oxytocin Differentially Affects Sucrose Taking and Seeking in Male and Female Rats

    OpenAIRE

    Zhou, Luyi; Ghee, Shannon M.; See, Ronald E.; Reichel, Carmela M.

    2015-01-01

    Oxytocin has a modulatory role in natural and drug reward processes. While the role of oxytocin in pair bonding and reproduction has been extensively studied, sex differences in conditioned and unconditioned behavioral responses to oxytocin treatment have not been fully characterized. Here, we determined whether male and female rats would show similar dose response curves in response to acute oxytocin on measures of locomotor activity, sucrose seeking, and sucrose intake. Male and freely cycl...

  1. Investigation of melt agglomeration process with a hydrophobic binder in combination with sucrose stearate.

    Science.gov (United States)

    Heng, Paul Wan Sia; Wong, Tin Wui; Cheong, Wai See

    2003-08-01

    The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added.

  2. Sucrose exposure in early life alters adult motivation and weight gain.

    Directory of Open Access Journals (Sweden)

    Cristianne R M Frazier

    2008-09-01

    Full Text Available The cause of the current increase in obesity in westernized nations is poorly understood but is frequently attributed to a 'thrifty genotype,' an evolutionary predisposition to store calories in times of plenty to protect against future scarcity. In modern, industrialized environments that provide a ready, uninterrupted supply of energy-rich foods at low cost, this genetic predisposition is hypothesized to lead to obesity. Children are also exposed to this 'obesogenic' environment; however, whether such early dietary experience has developmental effects and contributes to adult vulnerability to obesity is unknown. Using mice, we tested the hypothesis that dietary experience during childhood and adolescence affects adult obesity risk. We gave mice unlimited or no access to sucrose for a short period post-weaning and measured sucrose-seeking, food consumption, and weight gain in adulthood. Unlimited access to sucrose early in life reduced sucrose-seeking when work was required to obtain it. When high-sugar/high-fat dietary options were made freely-available, however, the sucrose-exposed mice gained more weight than mice without early sucrose exposure. These results suggest that early, unlimited exposure to sucrose reduces motivation to acquire sucrose but promotes weight gain in adulthood when the cost of acquiring palatable, energy dense foods is low. This study demonstrates that early post-weaning experience can modify the expression of a 'thrifty genotype' and alter an adult animal's response to its environment, a finding consistent with evidence of pre- and peri-natal programming of adult obesity risk by maternal nutritional status. Our findings suggest the window for developmental effects of diet may extend into childhood, an observation with potentially important implications for both research and public policy in addressing the rising incidence of obesity.

  3. Monitoring and control of enzymic sucrose hydrolysis using on-line biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Mandenius, C F; Buelow, L; Danielsson, B; Mosbach, K

    1985-02-01

    Previously reported flow microcalorimeter devices for enzymic reaction heat measurement, enzyme thermistors, have here been extended with systems for on-line sample treatment. Glucose analysis was performed by intermittent flow injection of 50 ..mu..l samples through such an enzyme thermistor device containing immobilized glucose oxidase and catalase. Sucrose analysis was performed by allowing diluted samples to continuously pass through an additional enzyme thermistor containing immobilized invertase. The reaction heats were recorded as temperature changes in the order of 10-50 m degrees C for concentration of 0.05-0.30 M glucose or sucrose present in the original non-diluted samples. The performance of this system was investigated by its ability to follow concentration changes obtained from a gradient mixer. The system was applied to monitoring and controlling the hydrolysis of sucrose to glucose and fructose in a plug-flow reactor with immobilized invertase. The reactor was continuously fed by a flow of sucrose of up to 0.3 M (100 g/l). Glucose and remaining sucrose were monitored in the effluent of the column. By using flow rate controlled feed pumps for sucrose and diluent the influent concentration of sucrose was varied while the overall flow rate remained constant. On-line control of the effluent concentration of glucose and sucrose was achieved by a proportional and integral regulator implemented on a microcomputer. Present concentration of glucose in the effluent could be maintained over an extended period of time despite changes in the overall capacity of the invertase reactor. Long delay times in the sensor system and the enzyme column made it necessary to carefully tune the control parameters. Changes of set-point value and temperature disturbances were used to verify accuracy of controlling performance. 32 references.

  4. Sucrose exposure in early life alters adult motivation and weight gain.

    Science.gov (United States)

    Frazier, Cristianne R M; Mason, Peggy; Zhuang, Xiaoxi; Beeler, Jeff A

    2008-09-17

    The cause of the current increase in obesity in westernized nations is poorly understood but is frequently attributed to a 'thrifty genotype,' an evolutionary predisposition to store calories in times of plenty to protect against future scarcity. In modern, industrialized environments that provide a ready, uninterrupted supply of energy-rich foods at low cost, this genetic predisposition is hypothesized to lead to obesity. Children are also exposed to this 'obesogenic' environment; however, whether such early dietary experience has developmental effects and contributes to adult vulnerability to obesity is unknown. Using mice, we tested the hypothesis that dietary experience during childhood and adolescence affects adult obesity risk. We gave mice unlimited or no access to sucrose for a short period post-weaning and measured sucrose-seeking, food consumption, and weight gain in adulthood. Unlimited access to sucrose early in life reduced sucrose-seeking when work was required to obtain it. When high-sugar/high-fat dietary options were made freely-available, however, the sucrose-exposed mice gained more weight than mice without early sucrose exposure. These results suggest that early, unlimited exposure to sucrose reduces motivation to acquire sucrose but promotes weight gain in adulthood when the cost of acquiring palatable, energy dense foods is low. This study demonstrates that early post-weaning experience can modify the expression of a 'thrifty genotype' and alter an adult animal's response to its environment, a finding consistent with evidence of pre- and peri-natal programming of adult obesity risk by maternal nutritional status. Our findings suggest the window for developmental effects of diet may extend into childhood, an observation with potentially important implications for both research and public policy in addressing the rising incidence of obesity.

  5. Sucrose and raffinose family oligosaccharides (RFOs) in soybean seeds as influenced by genotype and growing location.

    Science.gov (United States)

    Kumar, Vineet; Rani, Anita; Goyal, Lokesh; Dixit, Amit Kumar; Manjaya, J G; Dev, Jai; Swamy, M

    2010-04-28

    Sucrose content in soybean seeds is desired to be high because as a sweetness-imparting component, it helps in wider acceptance of soy-derived food products. Conversely, galactosyl derivatives of sucrose, that is, raffinose and stachyose, which are flatulence-inducing components, need to be in low concentration in soybean seeds not only for augmenting utilization of the crop in food uses but also for delivering soy meal with improved metabolizable energy for monogastric animals. In the present study, analysis of 148 soybean genotypes for sucrose and total raffinose family oligosaccharides (RFOs) contents revealed a higher variation (4.80-fold) for sucrose than for RFOs content (2.63-fold). High-performance liquid chromatography analyses revealed ranges of 0.64-2.53 and 2.09-7.1 mmol/100 g for raffinose and stachyose contents, respectively. As information concerning the environmental effects on the sucrose and RFOs content in soybean seeds is not available, we also investigated a set of seven genotypes raised at widely different geographical locations for these quality traits. Sucrose content was found to be significantly higher at cooler location (Palampur); however, differences observed for raffinose and stachyose contents across the growing locations were genotype-dependent. The results suggest that soybean genotypes grown at cooler locations may be better suited for processing soy food products with improved taste and flavor.

  6. Moderate high fat diet increases sucrose self-administration in young rats.

    Science.gov (United States)

    Figlewicz, Dianne P; Jay, Jennifer L; Acheson, Molly A; Magrisso, Irwin J; West, Constance H; Zavosh, Aryana; Benoit, Stephen C; Davis, Jon F

    2013-02-01

    We have previously reported that a moderately high fat diet increases motivation for sucrose in adult rats. In this study, we tested the motivational, neurochemical, and metabolic effects of the high fat diet in male rats transitioning through puberty, during 5-8 weeks of age. We observed that the high fat diet increased motivated responding for sucrose, which was independent of either metabolic changes or changes in catecholamine neurotransmitter metabolites in the nucleus accumbens. However, AGRP mRNA levels in the hypothalamus were significantly elevated. We demonstrated that increased activation of AGRP neurons is associated with motivated behavior, and that exogenous (third cerebroventricular) AGRP administration resulted in significantly increased motivation for sucrose. These observations suggest that increased expression and activity of AGRP in the medial hypothalamus may underlie the increased responding for sucrose caused by the high fat diet intervention. Finally, we compared motivation for sucrose in pubertal vs. adult rats and observed increased motivation for sucrose in the pubertal rats, which is consistent with previous reports that young animals and humans have an increased preference for sweet taste, compared with adults. Together, our studies suggest that background diet plays a strong modulatory role in motivation for sweet taste in adolescent animals. Published by Elsevier Ltd.

  7. Carbon particle induced foaming of molten sucrose for the preparation of carbon foams

    International Nuclear Information System (INIS)

    Narasimman, R.; Vijayan, Sujith; Prabhakaran, K.

    2014-01-01

    Graphical abstract: - Highlights: • An easy method for the preparation of carbon foam from sucrose is presented. • Wood derived activated carbon particles are used to stabilize the molten sucrose foam. • The carbon foams show relatively good mechanical strength. • The carbon foams show excellent CO 2 adsorption and oil absorption properties. • The process could be scaled up for the preparation of large foam bodies. - Abstract: Activated carbon powder was used as a foaming and foam setting agent for the preparation of carbon foams with a hierarchical pore structure from molten sucrose. The rheological measurements revealed the interruption of intermolecular hydrogen bonding in molten sucrose by the carbon particles. The carbon particles stabilized the bubbles in molten sucrose by adsorbing on the molten sucrose–gas interface. The carbon foams obtained at the activated carbon powder to sucrose weight ratios in the range of 0–0.25 had a compressive strength in the range of 1.35–0.31 MPa. The produced carbon foams adsorb 2.59–3.04 mmol/g of CO 2 at 760 mmHg at 273 K and absorb oil from oil–water mixtures and surfactant stabilized oil-in-water emulsions with very good selectivity and recyclability

  8. Nitrate Activation of Cytosolic Protein Kinases Diverts Photosynthetic Carbon from Sucrose to Amino Acid Biosynthesis

    Science.gov (United States)

    Champigny, Marie-Louise; Foyer, Christine

    1992-01-01

    The regulation of carbon partitioning between carbohydrates (principally sucrose) and amino acids has been only poorly characterized in higher plants. The hypothesis that the pathway of sucrose and amino acid biosynthesis compete for carbon skeletons and energy is widely accepted. In this review, we suggest a mechanism involving the regulation of cytosolic protein kinases whereby the flow of carbon is regulated at the level of partitioning between the pathways of carbohydrate and nitrogen metabolism via the covalent modulation of component enzymes. The addition of nitrate to wheat seedlings (Triticum aestivum) grown in the absence of exogenous nitrogen has a dramatic, if transient, impact on sucrose formation and on the activities of sucrose phosphate synthase (which is inactivated) and phosphoenolpyruvate carboxylase (which is activated). The activities of these two enzymes are modulated by protein phosphorylation in response to the addition of nitrate, but they respond in an inverse fashion. Sucrose phosphate synthase in inactivated and phosphoenolpyruvate carboxylase is activated. Nitrate functions as a signal metabolite activating the cytosolic protein kinase, thereby modulating the activities of at least two of the key enzymes in assimilate partitioning and redirecting the flow of carbon away from sucrose biosynthesis toward amino acid synthesis. PMID:16653003

  9. Pontine and Thalamic Influences on Fluid Rewards: III. Anticipatory Contrast for Sucrose and Corn Oil

    Science.gov (United States)

    Liang, Nu-Chu; Norgren, Ralph; Grigson, Patricia S

    2011-01-01

    An anticipatory contrast effect (ACE) occurs when, across daily trials, an animal comes to respond less than normally to a first stimulus when it is followed shortly by a second, more preferred solution. Classically, ACE is studied using a low (L) concentration of saccharin or sucrose, followed by access to a higher (H) concentration of sucrose. Subjects in the control condition have two bouts of access to the weaker solution presented on the same schedule. The ACE is measured by the difference in intake of the first bout low solution between subjects in the low-low (L-L) vs. the low-high (L-H) conditions. Here we used this paradigm with sham feeding rats and determined that nutritional feedback was unnecessary for the development of ACE with two concentrations of sucrose or with two concentrations of corn oil. Next we showed that ibotenic acid lesions centered in the orosensory thalamus spared ACEs for both sucrose and corn oil. In contrast, lesions of the pontine parabrachial nuclei (PBN), the second central relay for taste in the rat, disrupted ACEs for both sucrose and corn oil. Although the sensory modalities needed for the oral detection of fats remain controversial, it appears that the PBN is involved in processing the comparison of disparate concentrations of sucrose and oil reward. PMID:21703289

  10. Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels

    Science.gov (United States)

    Anton, Stephen D.; Martin, Corby K.; Han, Hongmei; Coulon, Sandra; Cefalu, William T.; Geiselman, Paula; Williamson, Donald A.

    2010-01-01

    Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low-calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. Design: 19 healthy lean (BMI = 20.0 – 24.9) and 12 obese (BMI = 30.0 – 39.9) individuals 18 to 50 years old completed three separate food test days during which they received preloads containing stevia (290 kcal), aspartame (290 kcal), or sucrose (493 kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20 minutes after the lunch preload. Despite the caloric difference in preloads (290 vs. 493 kcals), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia = 301 kcal, p Stevia preloads significantly lowered postprandial glucose levels compared to sucrose preloads (p stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload. PMID:20303371

  11. Oral sucrose for heel lance enhances adenosine triphosphate use in preterm neonates with respiratory distress.

    Science.gov (United States)

    Angeles, Danilyn M; Asmerom, Yayesh; Boskovic, Danilo S; Slater, Laurel; Bacot-Carter, Sharon; Bahjri, Khaled; Mukasa, Joseph; Holden, Megan; Fayard, Elba

    2015-01-01

    To examine the effects of oral sucrose on procedural pain, and on biochemical markers of adenosine triphosphate utilization and oxidative stress in preterm neonates with mild to moderate respiratory distress. Preterm neonates with a clinically required heel lance that met study criteria (n = 49) were randomized into three groups: (1) control (n = 24), (2) heel lance treated with placebo and non-nutritive sucking (n = 15) and (3) heel lance treated with sucrose and non-nutritive sucking (n = 10). Plasma markers of adenosine triphosphate degradation (hypoxanthine, xanthine and uric acid) and oxidative stress (allantoin) were measured before and after the heel lance. Pain was measured using the Premature Infant Pain Profile. Data were analyzed using repeated measures analysis of variance, chi-square and one-way analysis of variance. We found that in preterm neonates who were intubated and/or were receiving ⩾30% FiO2, a single dose of oral sucrose given before a heel lance significantly increased markers of adenosine triphosphate use. We found that oral sucrose enhanced adenosine triphosphate use in neonates who were intubated and/or were receiving ⩾30% FiO2. Although oral sucrose decreased pain scores, our data suggest that it also increased energy use as evidenced by increased plasma markers of adenosine triphosphate utilization. These effects of sucrose, specifically the fructose component, on adenosine triphosphate metabolism warrant further investigation.

  12. Analgesic effect of breast milk versus sucrose for analgesia during heel lance in late preterm infants.

    Science.gov (United States)

    Simonse, Eva; Mulder, Paul G H; van Beek, Ron H T

    2012-04-01

    The purpose of this trial was to investigate whether breast milk (either breastfed or bottle-fed) has a better analgesic effect than sucrose in newborns born at a postmenstrual age between 32 and 37 weeks. We conducted a randomized controlled trial at a secondary care neonatal unit in the Netherlands on 71 preterm neonates (postmenstrual age at birth 32-37 weeks), undergoing heel lance with an automated piercing device. Newborns were randomly assigned to breast milk (either breastfed or bottle-fed) administered during heel lance or oral sucrose administered before heel lance. We assessed the Premature Infant Pain Profile (PIPP) score (range, 0-21) to investigate whether there was a difference in pain score between neonates receiving breast milk and those receiving sucrose solution. There was no significant difference in mean PIPP score between neonates receiving breast milk (6.1) and those receiving sucrose (5.5), with a mean difference of 0.6 (95% confidence interval -1.6 to 2.8; P = .58). From this study, it cannot be concluded that breast milk has a better analgesic effect than sucrose in late preterm infants. From the results, it follows with 95% confidence that the analgesic effect of breast milk is not >1.6 points better and not > 2.8 points worse on the PIPP scale (SD 3.7) than the analgesic effect of sucrose in late preterm infants.

  13. Modulation of receptors and adenylate cyclase activity during sucrose feeding, food deprivation, and cold exposure

    International Nuclear Information System (INIS)

    Scarpace, P.J.; Baresi, L.A.; Morley, J.E.

    1987-01-01

    Thermogenesis in brown adipose tissue (BAT) serves as a regulator of body temperature and weight maintenance. Thermogenesis can be stimulated by catecholamine activation of adenylate cyclase through the β-adrenergic receptor. To investigate the effects of sucrose feeding, food deprivation, and cold exposure on the β-adrenergic pathway, adenylate cyclase activity and β-adrenergic receptors were assessed in rat BAT after 2 wk of sucrose feeding, 2 days of food deprivation, or 2 days of cold exposure. β-Adrenergic receptors were identified in BAT using [ 125 I]iodocyanopindolol. Binding sites had the characteristics of mixed β 1 - and β 2 -type adrenergic receptors at a ratio of 60/40. After sucrose feeding or cold exposure, there was the expected increase in BAT mitochondrial mass as measured by total cytochrome-c oxidase activity but a decrease in β-adrenergic receptor density due to a loss of the β 1 -adrenergic subtype. This BAT β-adrenergic receptor downregulation was tissue specific, since myocardial β-adrenergic receptors were unchanged with either sucrose feeding or cold exposure. Forskolin-stimulated adenylate cyclase activity increased in BAT after sucrose feeding or cold exposure but not after food deprivation. These data suggest that in BAT, sucrose feeding or cold exposure result in downregulation of β-adrenergic receptors and that isoproterenol-stimulated adenylate cyclase activity was limited by receptor availability

  14. Effects of sucrose reduction on the structural characteristics of sponge cake

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    Rosane Souza Cavalcante

    Full Text Available ABSTRACTThe consumption of reduced-calorie cakes has been increasing, however this has presented challenges to be overcome concerning the formation of their structure when the sucrose is substituted by alternative sweeteners, gums or thickening agents. The present study evaluated the internal characteristics of cakes with a reduction in sucrose, and the effects of its substitution on starch gelatinisation. Starting with a pre-established formulation, the sucrose was gradually substituted by a 1.0% mixture of sucralose in a 1.5% xanthan gum solution. In the substituted cake mix, the apparent viscosity and its thermal properties were evaluated using differential scanning calorimetry (DSC. Specific volume (SV and cell count (CC were evaluated in the cakes. As the sucrose content decreased (52.17 to 10.00%, the specific volume (1.94 to 0.7 mL/g, cell count (36.2 to 4.0 cell/cm2 and the apparent viscosity of the batter (337.56 to 631.40 cP were also reduced. The results showed that substituting the sucrose contributed greatly to the formation of defects in the cake structure (holes. From the data obtained, and thermograms of standard cake batters and those with a reduction in sucrose, it can be concluded that sucralose reduced the temperature of starch gelatinisation, speeding the process and causing compaction of the cake structure during baking, favouring the formation of bubbles throughout the batter.

  15. A study on alfalfa-dodder relationships by 14C-sucrose incorporation in their tissues

    International Nuclear Information System (INIS)

    Tsenova, M.

    1975-01-01

    Plant-parasite relationships between lesser-dodder (Cuscuta epithymum) and alfalfa (Medicago sativa) are investigated. 14 C-sucrose was incorporated via the cut stems of host and parasite into their tissues and the content of the free sugars, keto acids and free amino acids are determined. 14 C-sucrose was introduced also in lesser-dodder previously taken from the host-plant and immersed directly into radioactive sucrose. It is shown that the parasite intensively absorbs sucrose from the host-plant tissues using it as a source of energy and as a substrat for different synthetic processes. In the case when the parasite was previously taken away from the host-plant 14 C-sucrose taken up directly from the solution was used for the synthesis of various compounds (carbohydrates, amino- and keto acids). The suggestion was made that the respective enzyme systems are present in dodder tissues. The 14 C-glucose and 14 C-fructose content is an evidence for high invertase hydrolytic activity. The presence of 14 C-keto acids shows that the 14 C-sucrose incorporated in lesser-dodder tissues without the mediation of the host-plant was used as a respiratory substrate by the degradation following Krebs cycle. (author)

  16. Effect of sucrose ingestion on the performance of wild Anastrepha obliqua (Macquart) females (Diptera: Tephritidae)

    International Nuclear Information System (INIS)

    Fontellas, Tania M.L.; Zucoloto, Fernando S.

    2003-01-01

    Carbohydrates are the main source of energy for insects and the lack of these nutrients in the diet can cause serious damage to the biology of these arthropods. In order to better understand the effect of sucrose on the performance and dietary selection of adult Anastrepha obliqua (Macquart), the following experiments were carried out: 1) effect of different amount of sucrose on diet ingestion, longevity and egg production; 2) dietary selection that contains different amounts of sucrose, and 3) discrimination threshold for sucrose in adult individuals deprived or not of carbohydrates. The control diet showed the best results in relation to ingestion, longevity and egg production for these species, probably due to the fact that it presents an optimal nutritional balance between sucrose and yeast. The control diet was also the preferred diet of females, indicating a positive correlation between the nutritional value of a diet and chemical perception by A. obliqua. Sucrose-deprived females were able to perceive lower carbohydrate quantity than non-deprived females. This characteristic might represent a biological advantage since it reduces the food foraging time for these insects. (author)

  17. Bimodal Porous Scaffolds by Sequential Electro spinning of Poly(glycolic acid) with Sucrose Particles

    International Nuclear Information System (INIS)

    Wulkersdorfer, B.; Kao, K.K.; Agopian, V.G.; Ahn, A.; Dunn, J.C.; Wu, B.M.; Stelzner, M.; Kao, K.K.; Agopian, K.J.; Dunn, J.C.; Wu, B.M.; Stelzner, M.; Dunn, J.C.; Wu, B.M.

    2009-01-01

    Electro spinning is a method to produce fine, bio polymer mesh with a three-dimensional architecture that mimics native extra-cellular matrix. Due to the small fiber diameter created in this process, conventional electro spun scaffolds have pore sizes smaller than the diameter of most cells. These scaffolds have limited application in tissue engineering due to poor cell penetration. We developed a hybrid electro spinning/particulate leaching technique to create scaffolds with increased porosity and improved cellular ingrowth. Poly(glycolic acid) (PGA) and a sucrose-ethanol suspension were electro spun in equal, alternating sequences at intervals of one, two, and ten minutes each. The scaffolds revealed fiber mesh with micropores of 10 μm and uniformly distributed sucrose particles. Particulate leaching of sucrose from the one- or two-minute scaffolds revealed honeycomb structures with interconnected macro pores between 50 and 250 μm. Sucrose leaching from the ten-minute scaffolds resulted in laminated structures with isolated macro pores between 200 and 350 μm. Macro pore size was directly proportional to the duration of the sucrose spinning interval. After 24 hours of cell culture, conventionally spun scaffolds demonstrated no cellular penetration. Conversely, the PGA/sucrose scaffolds demonstrated deep cellular penetration. This hybrid technique represents a novel method of generating electro spun scaffolds with interconnected pores suitable for cellular ingrowth.

  18. Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels.

    Science.gov (United States)

    Anton, Stephen D; Martin, Corby K; Han, Hongmei; Coulon, Sandra; Cefalu, William T; Geiselman, Paula; Williamson, Donald A

    2010-08-01

    Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. 19 healthy lean (BMI=20.0-24.9) and 12 obese (BMI=30.0-39.9) individuals 18-50 years old completed three separate food test days during which they received preloads containing stevia (290kcal), aspartame (290kcal), or sucrose (493kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20min after the lunch preload. Despite the caloric difference in preloads (290kcal vs. 493kcal), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia=301kcal, paspartame=330kcal, paspartame and sucrose preloads (paspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload. Published by Elsevier Ltd.

  19. Sucrose-induced anthocyanin accumulation in vegetative tissue of Petunia plants requires anthocyanin regulatory transcription factors.

    Science.gov (United States)

    Ai, Trinh Ngoc; Naing, Aung Htay; Arun, Muthukrishnan; Lim, Sun-Hyung; Kim, Chang Kil

    2016-11-01

    The effects of three different sucrose concentrations on plant growth and anthocyanin accumulation were examined in non-transgenic (NT) and transgenic (T 2 ) specimens of the Petunia hybrida cultivar 'Mirage rose' that carried the anthocyanin regulatory transcription factors B-Peru+mPAP1 or RsMYB1. Anthocyanin accumulation was not observed in NT plants in any treatments, whereas a range of anthocyanin accumulation was observed in transgenic plants. The anthocyanin content detected in transgenic plants expressing the anthocyanin regulatory transcription factors (B-Peru+mPAP1 or RsMYB1) was higher than that in NT plants. In addition, increasing sucrose concentration strongly enhanced anthocyanin content as shown by quantitative real-time polymerase chain reaction (qRT-PCR) analysis, wherein increased concentrations of sucrose enhanced transcript levels of the transcription factors that are responsible for the induction of biosynthetic genes involved in anthocyanin synthesis; this pattern was not observed in NT plants. In addition, sucrose affected plant growth, although the effects were different between NT and transgenic plants. Taken together, the application of sucrose could enhance anthocyanin production in vegetative tissue of transgenic Petunia carrying anthocyanin regulatory transcription factors, and this study provides insights about interactive effects of sucrose and transcription factors in anthocyanin biosynthesis in the transgenic plant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Inhibition of acid-induced lung injury by hyperosmolar sucrose in rats.

    Science.gov (United States)

    Safdar, Zeenat; Yiming, Maimiti; Grunig, Gabriele; Bhattacharya, Jahar

    2005-10-15

    Acid aspiration causes acute lung injury (ALI). Recently, we showed that a brief intravascular infusion of hyperosmolar sucrose, given concurrently with airway acid instillation, effectively blocks the ensuing ALI. The objective of the present study was to determine the extent to which intravascular infusion of hyperosmolar sucrose might protect against acid-induced ALI when given either before or after acid instillation. Our studies were conducted in anesthetized rats and in isolated, blood-perfused rat lungs. We instilled HCl through the airway, and we quantified lung injury in terms of the extravascular lung water (EVLW) content, filtration coefficient (Kfc), and cell counts and protein concentration in the bronchoalveolar lavage. We infused hyperosmolar sucrose via the femoral vein. In anesthetized rats, airway HCl instillation induced ALI as indicated by a 52% increase of EVLW and a threefold increase in Kfc. However, a 15-min intravenous infusion of hyperosmolar sucrose given up to 1 h before or 30 min after acid instillation markedly blunted the increases in EVLW, as well as the increases in cell count, and in protein concentration in the bronchoalveolar lavage. Hyperosmolar pretreatment also blocked the acid-induced increase of Kfc. Studies in isolated perfused lungs indicated that the protective effect of hyperosmolar sucrose was leukocyte independent. We conclude that a brief period of vascular hyperosmolarity protects against acid-induced ALI when the infusion is administered shortly before, or shortly after, acid instillation in the airway. The potential applicability of hyperosmolar sucrose in therapy for ALI requires consideration.

  1. Vacuolar invertase gene silencing in potato (Solanum tuberosum L. improves processing quality by decreasing the frequency of sugar-end defects.

    Directory of Open Access Journals (Sweden)

    Xiaobiao Zhu

    Full Text Available Sugar-end defect is a tuber quality disorder and persistent problem for the French fry processing industry that causes unacceptable darkening of one end of French fries. This defect appears when environmental stress during tuber growth increases post-harvest vacuolar acid invertase activity at one end of the tuber. Reducing sugars produced by invertase form dark-colored Maillard reaction products during frying. Acrylamide is another Maillard reaction product formed from reducing sugars and acrylamide consumption has raised health concerns worldwide. Vacuolar invertase gene (VInv expression was suppressed in cultivars Russet Burbank and Ranger Russet using RNA interference to determine if this approach could control sugar-end defect formation. Acid invertase activity and reducing sugar content decreased at both ends of tubers. Sugar-end defects and acrylamide in fried potato strips were strongly reduced in multiple transgenic potato lines. Thus vacuolar invertase silencing can minimize a long-standing French fry quality problem while providing consumers with attractive products that reduce health concerns related to dietary acrylamide.

  2. Expression Patterns, Activities and Carbohydrate-Metabolizing Regulation of Sucrose Phosphate Synthase, Sucrose Synthase and Neutral Invertase in Pineapple Fruit during Development and Ripening

    Science.gov (United States)

    Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

    2012-01-01

    Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion. PMID:22949808

  3. Sucrose-enhanced biosynthesis of medicinally important antioxidant secondary metabolites in cell suspension cultures of Artemisia absinthium L.

    Science.gov (United States)

    Ali, Mohammad; Abbasi, Bilal Haider; Ahmad, Nisar; Ali, Syed Shujait; Ali, Shahid; Ali, Gul Shad

    2016-12-01

    Natural products are gaining tremendous importance in pharmaceutical industry and attention has been focused on the applications of in vitro technologies to enhance yield and productivity of such products. In this study, we investigated the accumulation of biomass and antioxidant secondary metabolites in response to different carbohydrate sources (sucrose, maltose, fructose and glucose) and sucrose concentrations (1, 3, 5, 7 and 9 %). Moreover, the effects of 3 % repeated sucrose feeding (day-12, -18 and -24) were also investigated. The results showed the superiority of disaccharides over monosaccharides for maximum biomass and secondary metabolites accumulation. Comparable profiles for maximum biomass were observed in response to sucrose and maltose and initial sucrose concentrations of 3 and 5 %. Maximum total phenolic and total flavonoid contents were displayed by cultures treated with sucrose and maltose; however, initial sucrose concentrations of 5 and 7 % were optimum for both classes of metabolites, respectively. Following 3 % extra sucrose feeding, cultures fed on day-24 (late-log phase) showed higher biomass, total phenolic and total flavonoid contents as compared to control cultures. Highest antioxidant activity was exhibited by maltose-treated cultures. Moreover, sucrose-treated cultures displayed positive correlation of antioxidant activity with total phenolics and total flavonoids production. This work describes the stimulatory role of disaccharides and sucrose feeding strategy for higher accumulation of phenolics and flavonoids, which could be potentially scaled up to bioreactor level for the bulk production of these metabolites in suspension cultures of A. absinthium.

  4. ZINC-INDUCED HYPERLEPTINEMIA IN RATS RELATED TO THE AMELIORATION OF SUCROSE-INDUCED OBESITY WITH ZINC REPLETION

    International Nuclear Information System (INIS)

    HEIBASHY, M.I.; EL-NAHLA, A.M.; ASHOUR, I.; SALEH, SH.Y.A.

    2008-01-01

    Thirty adult albino rats (Rattus rattus) at 6 weeks of age were divided into three groups (ten for each). The first group was fed a standard laboratory diet for 8 weeks (control). The second group was made obese by giving them 32% sucrose solution in addition to the standard laboratory diet .The third group was received zinc supplementation (50 mg zinc acetate/ litre) with their sucrose solution. Body weight of all rats was measured weekly for 8 weeks. At 14 weeks of age, rats were killed and fasting blood samples were obtained. Serum glucose, insulin, cholesterol, triglyceride, leptin, tumour necrosis factor-α and zinc were measured.Results showed remarkable changes in body weights in sucrose fed rats only when compared to control and supplemented zinc rats group. Serum glucose, insulin, cholesterol and triglycerides were significantly increased in sucrose fed rats than both control and sucrose with zinc group. Serum leptin showed significant increase in sucrose fed rats than control and also showed higher significant value in sucrose fed rats supplemented with zinc comparing with sucrose fed rats and control ones. Tumour necrosis factor-? did not show any significant difference between all groups. Serum zinc concentration was decreased significantly in sucrose fed rats as compared to control. On the other hand, it was increased significantly in sucrose fed rats supplemented with zinc than other both groups. It could be concluded that zinc supplementation induced hyperleptinemia caused ameliorating effects in obese rats

  5. Identification of a 170-kDa protein associated with the vacuolar Na+/H+ antiport of Beta vulgaris.

    Science.gov (United States)

    Barkla, B J; Blumwald, E

    1991-12-15

    The effect of the addition of amiloride to the growth medium was tested on the Na+/H+ antiport activity of tonoplast vesicles isolated from sugar beet (beta vulgaris L.) cell suspensions. Cells grown in the presence of NaCl and amiloride displayed an increased antiport activity. Analysis of the kinetic data showed that while the affinity of the antiport for Na+ ions did not change, the maximal velocity of the Na+/H+ exchange increased markedly. These results suggest the addition of more antiport molecules to the tonoplast and/or an increase in the turnover rate of the Na+/H+ exchange. The increase in activity of the antiport by the presence of amiloride was correlated with the enhanced synthesis of a tonoplast 170-kDa polypeptide. The increased synthesis of this polypeptide was detected not only upon exposure of the cells to amiloride but also when the cells were exposed to high NaCl concentrations. Polyclonal antibodies against the 170-kDa polypeptide almost completely inhibited the antiport activity. These results suggest the association of the 170-kDa polypeptide with the vacuolar Na+/H+ antiport.

  6. Clinical features of progressive vacuolar hepatopathy in Scottish Terriers with and without hepatocellular carcinoma: 114 cases (1980-2013).

    Science.gov (United States)

    Cortright, Catherine C; Center, Sharon A; Randolph, John F; McDonough, Sean P; Fecteau, Kellie A; Warner, Karen L; Chiapella, Ann M; Pierce, Rhonda L; Graham, A Heather; Wall, Linda J; Heidgerd, John H; Degen, Melisa A; Lucia, Patricia A; Erb, Hollis N

    2014-10-01

    To characterize signalment, clinical features, clinicopathologic variables, hepatic ultrasonographic characteristics, endocrinologic profiles, treatment response, and age at death of Scottish Terriers with progressive vacuolar hepatopathy (VH) with or without hepatocellular carcinoma (HCC). Retrospective case series. 114 Scottish Terriers with progressive VH. Electronic databases from 1980 to 2013 were searched for adult (age > 1 year) Scottish Terriers with histopathologic diagnoses of diffuse glycogen-like VH. Available sections of liver specimens were histologically reevaluated to confirm diffuse VH with or without HCC; 8 dogs with HCC only had neoplastic tissue available. Physical examination, clinicopathologic, treatment, and survival data were obtained. 39 of 114 (34%) dogs with VH had HCC detected at surgery or necropsy or by abdominal ultrasonography. Histologic findings indicated that HCC was seemingly preceded by dysplastic hepatocellular foci. No significant differences were found in clinicopathologic variables or age at death between VH-affected dogs with or without HCC. Fifteen of 26 (58%) dogs with high hepatic copper concentrations had histologic features consistent with copper-associated hepatopathy. Although signs consistent with hyperadrenocorticism were observed in 40% (46/114) of dogs, definitive diagnosis was inconsistently confirmed. Assessment of adrenal sex hormone concentrations before and after ACTH administration identified high progesterone and androstenedione concentrations in 88% (22/25) and 80% (20/25) of tested dogs, respectively. Results suggested that VH in Scottish Terriers may be linked to adrenal steroidogenesis and a predisposition to HCC. In dogs with VH, frequent serum biochemical analysis and ultrasonographic surveillance for early tumor detection are recommended.

  7. The Loss of Vacuolar Protein Sorting 11 (vps11) Causes Retinal Pathogenesis in a Vertebrate Model of Syndromic Albinism

    Science.gov (United States)

    Thomas, Jennifer L.; Vihtelic, Thomas S.; denDekker, Aaron D.; Willer, Gregory; Luo, Xixia; Murphy, Taylor R.; Gregg, Ronald G.; Hyde, David R.

    2011-01-01

    Purpose. To establish the zebrafish platinum mutant as a model for studying vision defects caused by syndromic albinism diseases such as Chediak-Higashi syndrome, Griscelli syndrome, and Hermansky-Pudlak syndrome (HPS). Methods. Bulked segregant analysis and candidate gene sequencing revealed that the zebrafish platinum mutation is a single-nucleotide insertion in the vps11 (vacuolar protein sorting 11) gene. Expression of vps11 was determined by RT-PCR and in situ hybridization. Mutants were analyzed for pigmentation defects and retinal disease by histology, immunohistochemistry, and transmission electron microscopy. Results. Phenocopy and rescue experiments determined that a loss of Vps11 results in the platinum phenotype. Expression of vps11 appeared ubiquitous during zebrafish development, with stronger expression in the developing retina and retinal pigmented epithelium (RPE). Zebrafish platinum mutants exhibited reduced pigmentation in the body and RPE; however, melanophore development, migration, and dispersion occurred normally. RPE, photoreceptors, and inner retinal neurons formed normally in zebrafish platinum mutants. However, a gradual loss of RPE, an absence of mature melanosomes, and the subsequent degradation of RPE/photoreceptor interdigitation was observed. Conclusions. These data show that Vps11 is not necessary for normal retinal development or initiation of melanin biosynthesis, but is essential for melanosome maturation and healthy maintenance of the RPE and photoreceptors. PMID:21330665

  8. The LRRC8A Mediated “Swell Activated” Chloride Conductance Is Dispensable for Vacuolar Homeostasis in Neutrophils

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    Philippe Behe

    2017-05-01

    Full Text Available The dialysis of human and mouse neutrophils in patch clamp experiments in the conventional whole-cell mode induces the emergence of a chloride (Cl- current that appeared to be primarily regulated by cytoplasmic ionic strength. The characteristics of this current resembled that of the classical, and ubiquitous volume-sensitive outwardly rectifying Cl- current: strong outward rectification, selectivity sequence of the Eisenman1 type, insensitivity to external pH and strong inhibition by tamoxifen, DCPIB and WW781. We show that this current is essentially supported by the leucine rich repeat containing 8 A (LRRC8A; the naturally occurring LRRC8A truncation mutant in ebo/ebo mice drastically reduced Cl- conductance in neutrophils. Remarkably, the residual component presents a distinct pharmacology, but appears equally potentiated by reduced ionic strength. We have investigated the role of the LRRC8A-supported current in the ionic homeostasis of the phagosomal compartment. The vacuolar pH, measured using SNARF-1 labeled Candida albicans, normally rises because of NADPH oxidase activity, and this elevation is blocked by certain Cl- channel inhibitors. However, the pH rise remains intact in neutrophils from the ebo/ebo mice which also demonstrate preserved phagocytic and respiratory burst capacities and normal-sized vacuoles. Thus, the LRRC8A-dependent conductance of neutrophils largely accounts for their “swell activated” Cl- current, but is not required for homeostasis of the phagosomal killing compartment.

  9. Inhibition of the Vacuolar-like ATPase from Halobacterium saccharovorum by Thiol Reagents: Evidence for Different Functional Thiols

    Science.gov (United States)

    Hochstein, L. I.; Stanlotter, H.; Emrich, E.; Morrison, David (Technical Monitor)

    1994-01-01

    N-Ethylmaleimide (NEM) inhibited the vacuolar-like ATPase from Halobacterium saccharovorum (K(sub i) approximately 1 mM) by modifying one or more of the thiols located on the largest of the subunit. ATP protected against inhibition and coincidentally prevented NEM binding which suggested that NEM acts at or near the catalytic site. p-Chloromercuriphenylsulfonate (PCMS) also inhibited this ATPase (K(sub i) approximately 90 microM). ATP did not protect against PCMS inhibition. Dithiothreitol (DTT) partially reversed PCMS inhibition and restored approximately half of the initial activity of 90% inhibited enzyme. DTT did not restore activity of the NEM-inhibited enzyme or the PCMS-inhibited enzyme when it was subsequently incubated with NEM. The failure of ATP to protect against PCMS inhibition and the inability of DTT to restore activity of enzyme incubated in the presence of PCMS and NEM suggests these reagents react with different thiols and that the PCMS-sensitive thiol may have a structural role.

  10. CHANGES OF SUCROSE CONTENT AND INVERTASE ACTIVITY DURING SUGARCANE STEM STORAGE

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    Tri Agus Siswoyo

    2016-10-01

    Full Text Available Invertases (beta-D-fructofuranosidase, E.C. 3.2.1.26 are the key enzymes involved in sucrose metabolism in sugarcane plants. They are highly correlated with sucrose and reducing sugar contents during plant growth. The sugarcane plants have two kinds of invertases, namely neutral invertase (NI and acid invertase (AI. They have different function in sucrose accumulation. The research aimed to study the role of AI and NI in accumulation of reducing sugar during storage of sugarcane stems. Plant materials of 18-month-old field grown sugarcane of the commercial variety R-579 (wet-land and M 442-51 (dry-land were used. Three internodes were sampled to represent immature (internode 1-8/F1, maturing (internode 9-16/F2, and mature (internode 17-24/F3 stem tissues. All tissues were stored for 0-9 days at room temperature (28-32oC and each day, the samplewas extracted to determine invertase activity, total soluble protein, and sugar contents. This observation was valid for invertase activity expressed on a protein basis. At the initiateharvested (0-3 days, NI had a higher specific activity than AI in the sucrose-accumulating region of the sugarcane stems. Negative significant correlation was found between NI specific activity and sucrose accumulation (r2 = 0.41, P < 0.05. AI showed a higher specific activity after 4 days harvested and had negative correlation with sucrose accumulation (r2 = 0.40, P < 0.05. These results showed that NI could be more  responsible in sucrose hydrolisis than AI at early storage of sugarcane stems.

  11. Short-term effects of glucose and sucrose on cognitive performance and mood in elderly people.

    Science.gov (United States)

    van der Zwaluw, Nikita L; van de Rest, Ondine; Kessels, Roy P C; de Groot, Lisette C P G M

    2014-01-01

    In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (-0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.

  12. Social defeat-induced anhedonia: effects on operant sucrose-seeking behavior

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    Danai eRiga

    2015-08-01

    Full Text Available Reduced capacity to experience pleasure, also known as anhedonia, is a key feature of the depressive state and is associated with poor disease prognosis and treatment outcome. Various behavioral readouts (e.g. reduced sucrose intake have been employed in animal models of depression as a measure of anhedonia. However, several aspects of anhedonia are poorly represented within the repertoire of current preclinical assessments. We recently adopted the social defeat-induced persistent stress (SDPS paradigm that models a maintained depressive-like state in the rat, including social withdrawal and deficits in short-term spatial memory. Here we investigated whether SDPS elicited persistent deficits in natural reward evaluation, as part of anhedonia. We examined cue-paired operant sucrose self-administration, enabling us to study acquisition, motivation, extinction and relapse to sucrose seeking following SDPS. Furthermore, we addressed whether guanfacine, an α2-adrenergic agonist that reduces stress-triggered maladaptive behavioral responses to drugs of abuse, could relief from SDPS-induced anhedonia. SDPS, consisting of 5 social defeat episodes followed by prolonged (≥8 weeks social isolation, did not affect sucrose consumption during acquisition of self-administration. However, it strongly enhanced the motivational drive to acquire a sucrose reward in progressive ratio training. Moreover, SDPS induced initial resilience to extinction and rendered animals more sensitive to cue-induced reinstatement of sucrose-seeking. Guanfacine treatment attenuated SDPS-induced motivational overdrive and limited reinstatement of sucrose seeking, normalizing behavior to control levels. Together, our data indicate that long after the termination of stress exposure, SDPS induces guanfacine-reversible deficits in evaluation of a natural reward. Importantly, the SDPS-triggered anhedonia reflects many aspects of the human phenotype, including impaired motivation and

  13. A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes

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    Yanhan Wang

    2016-11-01

    Full Text Available Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS. The level of macrophage-inflammatory protein-2 (MIP-2 and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne.

  14. Trial of Music, Sucrose, and Combination Therapy for Pain Relief during Heel Prick Procedures in Neonates.

    Science.gov (United States)

    Shah, Swapnil R; Kadage, Shahajahan; Sinn, John

    2017-11-01

    To compare the effectiveness of music, oral sucrose, and combination therapy for pain relief in neonates undergoing a heel prick procedure. This randomized, controlled, blinded crossover clinical trial included stable neonates >32 weeks of postmenstrual age. Each neonate crossed over to all 3 interventions in random order during consecutive heel pricks. A video camera on mute mode recorded facial expressions, starting 2 minutes before until 7 minutes after the heel prick. The videos were later analyzed using the Premature Infant Pain Profile-Revised (PIPP-R) scale once per minute by 2 independent assessors, blinded to the intervention. The PIPP-R scores were compared between treatment groups using Friedman test. For the 35 participants, the postmenstrual age was 35 weeks (SD, 2.3) with an average weight of 2210 g (SD, 710). The overall median PIPP-R scores following heel prick over 6 minutes were 4 (IQR 0-6), 3 (IQR 0-6), and 1 (IQR 0-3) for the music, sucrose, and combination therapy interventions, respectively. The PIPP-R scores were significantly lower at all time points after combination therapy compared with the groups given music or sucrose alone. There was no difference in PIPP-R scores between the music and sucrose groups. In relatively stable and mature neonates, the combination of music therapy with sucrose provided better pain relief during heel prick than when sucrose or music was used alone. Recorded music in isolation had a similar effect to the current gold standard of oral sucrose. www.anzctr.org.au ACTRN12615000271505. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Sucrose-induced analgesia during early life modulates adulthood learning and memory formation.

    Science.gov (United States)

    Nuseir, Khawla Q; Alzoubi, Karem H; Alabwaini, Jehad; Khabour, Omar F; Kassab, Manal I

    2015-06-01

    This study is aimed at examining the long-term effects of chronic pain during early life (postnatal day 0 to 8weeks), and intervention using sucrose, on cognitive functions during adulthood in rats. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution or paracetamol was administered for analgesia before the paw prick. Control groups include tactile stimulation to account for handling and touching the paws, and sucrose alone was used. All treatments were started on day one of birth and continued for 8weeks. At the end of the treatments, behavioral studies were conducted to test the spatial learning and memory using radial arm water maze (RAWM), as well as pain threshold via foot-withdrawal response to a hot plate apparatus. Additionally, the hippocampus was dissected, and blood was collected. Levels of neurotrophins (BDNF, IGF-1 and NT-3) and endorphins were assessed using ELISA. The results show that chronic noxious stimulation resulted in comparable foot-withdrawal latency between noxious and tactile groups. On the other hand, pretreatment with sucrose or paracetamol increased pain threshold significantly both in naive rats and noxiously stimulated rats (Pmemory, and sucrose treatment prevented such impairment (Pmemory impairment, and pretreatment with sucrose prevented this impairment via mechanisms that seem to involve BDNF. As evident in the results, sucrose, whether alone or in the presence of pre-noxious stimulation, increases pain threshold in such circumstances; most likely via a mechanism that involves an increase in endogenous opioids. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Arsenic and Antimony Transporters in Eukaryotes

    Directory of Open Access Journals (Sweden)

    Ewa Maciaszczyk-Dziubinska

    2012-03-01

    Full Text Available Arsenic and antimony are toxic metalloids, naturally present in the environment and all organisms have developed pathways for their detoxification. The most effective metalloid tolerance systems in eukaryotes include downregulation of metalloid uptake, efflux out of the cell, and complexation with phytochelatin or glutathione followed by sequestration into the vacuole. Understanding of arsenic and antimony transport system is of high importance due to the increasing usage of arsenic-based drugs in the treatment of certain types of cancer and diseases caused by protozoan parasites as well as for the development of bio- and phytoremediation strategies for metalloid polluted areas. However, in contrast to prokaryotes, the knowledge about specific transporters of arsenic and antimony and the mechanisms of metalloid transport in eukaryotes has been very limited for a long time. Here, we review the recent advances in understanding of arsenic and antimony transport pathways in eukaryotes, including a dual role of aquaglyceroporins in uptake and efflux of metalloids, elucidation of arsenic transport mechanism by the yeast Acr3 transporter and its role in arsenic hyperaccumulation in ferns, identification of vacuolar transporters of arsenic-phytochelatin complexes in plants and forms of arsenic substrates recognized by mammalian ABC transporters.

  17. Arsenic and Antimony Transporters in Eukaryotes

    Science.gov (United States)

    Maciaszczyk-Dziubinska, Ewa; Wawrzycka, Donata; Wysocki, Robert

    2012-01-01

    Arsenic and antimony are toxic metalloids, naturally present in the environment and all organisms have developed pathways for their detoxification. The most effective metalloid tolerance systems in eukaryotes include downregulation of metalloid uptake, efflux out of the cell, and complexation with phytochelatin or glutathione followed by sequestration into the vacuole. Understanding of arsenic and antimony transport system is of high importance due to the increasing usage of arsenic-based drugs in the treatment of certain types of cancer and diseases caused by protozoan parasites as well as for the development of bio- and phytoremediation strategies for metalloid polluted areas. However, in contrast to prokaryotes, the knowledge about specific transporters of arsenic and antimony and the mechanisms of metalloid transport in eukaryotes has been very limited for a long time. Here, we review the recent advances in understanding of arsenic and antimony transport pathways in eukaryotes, including a dual role of aquaglyceroporins in uptake and efflux of metalloids, elucidation of arsenic transport mechanism by the yeast Acr3 transporter and its role in arsenic hyperaccumulation in ferns, identification of vacuolar transporters of arsenic-phytochelatin complexes in plants and forms of arsenic substrates recognized by mammalian ABC transporters. PMID:22489166

  18. Effect of Incubation Time and Sucrose Addition on the Characteristics of Cheese Whey Yoghurt

    Science.gov (United States)

    Nurhartadi, E.; Utami, R.; Nursiwi, A.; Sari, A. M.; Widowati, E.; Sanjaya, A. P.; Esnadewi, E. A.

    2017-04-01

    The effect of incubation time and concentration of sucrose addition on the characteristics of cheese whey yogurt (lactic acid content, pH, total lactic acid bacteria, antioxidant activity, viscosity) and sensory characteristics (color, odor, flavor, consistency, and overalls) were investigated. The cheese whey yogurt fermentation process was carried out for 24h and 36h with the addition of sucrose 8, 10, and 12% (w/w) of total solid, respectively. The results showed that the lactic acid content, total lactic acid bacteria, antioxidant activity, and viscosity of cheese whey yogurt were affected by the incubation time and sucrose addition. The level of pH of yogurt which was incubated at 24h and 36h were relatively in the same levels, which were 4.51 up to 4.63. Due the sensory characteristic of cheese whey yogurt the panellists gave the high score for the cheese whey yogurt which was incubated at 24h and sucrose addition 12% (w/w) of total solid. The cheese whey yogurt has 0.41% lactic acid content; pH 4.51; 7.09 log total lactic acid bacteria cells / ml; 5.78% antioxidant activity; and 5.97 cP viscosity. The best sensory and physico-chemical characteristic of cheese whey yogurt was achieved by 24h incubation time and 12% concentration of sucrose addition.

  19. Cryopreservation at -75 °C of Agaricus subrufescens on wheat grains with sucrose

    Directory of Open Access Journals (Sweden)

    Lienine Luiz Zaghi Júnior

    Full Text Available Abstract Agaricus subrufescens is a basidiomycete which is studied because of its medicinal and gastronomic importance; however, less attention has been paid to its preservation. This study aimed to evaluate the effect of sucrose addition to substrate and cryotube on the viability of Agaricus subrufescens cryopreserved at -20 °C and at -75 °C for one and two years. Zero, 10% or 20% sucrose was added to potato dextrose agar or wheat grain. The mycelia were cryopreserved in the absence of cryoprotectant or with sucrose solutions at 15%, 30% or 45%. After one or two years at -75 °C or at -20 °C, mycelia were thawed and evaluated about viability, initial time of growth, colony diameter and genomic stability. Cryopreservation at -20 °C is not effective to keep mycelial viability of this fungus. Cryopreservation at -75 °C is effective when sucrose is used in substrates and/or cryotubes. Without sucrose, cryopreservation at -75 °C is effective only when wheat grains are used. Physiological characteristic as mycelial colony diameter is negatively affected when potato dextrose agar is used and unaffected when wheat grain is used after two-year cryopreservation at -75 °C. The fungus genome does not show alteration after two-year cryopreservation at -75 °C.

  20. Antisense repression of sucrose phosphate synthase in transgenic muskmelon alters plant growth and fruit development

    International Nuclear Information System (INIS)

    Tian, Hongmei; Ma, Leyuan; Zhao, Cong; Hao, Hui; Gong, Biao; Yu, Xiyan; Wang, Xiufeng

    2010-01-01

    To unravel the roles of sucrose phosphate synthase (SPS) in muskmelon (Cucumis melo L.), we reduced its activity in transgenic muskmelon plants by an antisense approach. For this purpose, an 830 bp cDNA fragment of muskmelon sucrose phosphate synthase was expressed in antisense orientation behind the 35S promoter of the cauliflower mosaic virus. The phenotype of the antisense plants clearly differed from that of control plants. The transgenic plant leaves were markedly smaller, and the plant height and stem diameter were obviously shorter and thinner. Transmission electron microscope observation revealed that the membrane degradation of chloroplast happened in transgenic leaves and the numbers of grana and grana lamella in the chloroplast were significantly less, suggesting that the slow growth and weaker phenotype of transgenic plants may be due to the damage of the chloroplast ultrastructure, which in turn results in the decrease of the net photosynthetic rate. The sucrose concentration and levels of sucrose phosphate synthase decreased in transgenic mature fruit, and the fruit size was smaller than the control fruit. Together, our results suggest that sucrose phosphate synthase may play an important role in regulating the muskmelon plant growth and fruit development.

  1. Role of plaque in the clearance of salivary sucrose and its influence on salivary ph.

    Science.gov (United States)

    Kumar, A; Hedge, R; Dixit, U

    2011-01-01

    The prevalence of dental caries in children, in India, is higher than many of the industrialized countries. The sugar most commonly associated with dental caries is sucrose, as the microorganisms in the dental plaque have the ability to convert this dietary constituent into various organic acids. This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and to study the effect of the presence of plaque on salivary pH, following sucrose clearance. Salivary sucrose determination was done by using the anthrone technique. A Digital MHOS pH meter estimated the salivary pH. Presence of plaque increased the salivary sucrose clearance time and decreased the salivary pH at various time intervals. The microbial etiology of dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and pH lowering, and the cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

  2. EPR and UV spectrometry investigation of sucrose irradiated with carbon particles

    International Nuclear Information System (INIS)

    Karakirova, Yordanka; Yordanov, Nicola D.

    2010-01-01

    Solid state/EPR (SS/EPR) dosimeters of carbon ions irradiated sucrose are studied with EPR, and their water solutions - with UV spectroscopy. Doses between 20 and 200 Gy are used with linear energy transfer (LET) values for carbon ions of 63, 77, 96 and 230 keV μm -1 . After irradiation all samples show typical for irradiated sucrose EPR and UV spectra. The obtained data are compared with those previously reported for nitrogen particles and gamma rays irradiated sucrose. The identical shape of both the EPR and UV spectra of irradiated with various type radiation samples suggests that generated free radicals are not influenced by the nature of radiation. The lack of difference in the line width of the separate lines or the whole EPR spectrum, obtained for gamma and heavy particles irradiation, suggests negligible spin-spin interaction among the radiation-generated free radicals in the samples. The linear dependence of the EPR response on the absorbed dose radiation is found to be higher when generated by gamma rays, than by the same absorbed dose of heavy particles. In addition, the EPR response for carbon ions is higher than that for nitrogen ions. Water solutions of irradiated sucrose exhibit UV spectrum with absorption maximum at 267 nm, attributed to the recombination products of free radicals. The UV band intensity depends on the absorbed dose radiation. The UV spectra obtained for carbon, nitrogen and gamma rays irradiated sucrose are also compared.

  3. Heavy-ion-induced sucrose radicals investigated using EPR and UV spectroscopy

    Science.gov (United States)

    Nakagawa, Kouichi; Karakirova, Yordanka; Yordanov, Nicola D.

    2015-01-01

    The potential use of a sucrose dosimeter for estimating both linear energy transfer (LET) and the absorbed dose of heavy ion and X-ray radiation was investigated. The stable free radicals were produced when sucrose was irradiated with heavy ions, such as helium, carbon, silicon and neon ions, and when the X-ray radiation was similar to the obtained electron paramagnetic resonance (EPR) spectra, which were ∼7 mT wide and composed of several hyperfine structures. In addition, the total spin concentration resulting from heavy-ion irradiation increased linearly as the absorbed dose increased, and decreased logarithmically as the LET increased. These empirical relations imply that the LET at a certain dose can be determined from the spin concentration. For sucrose and alanine, both cross-sections following C-ion irradiation with a 50 Gy dose were ∼1.3 × 10−12 [μm2], taking into account the molecular size of the samples. The values of these cross-sections imply that multiple ionizing particles were involved in the production of stable radicals. Furthermore, UV absorbance at 267 nm of an aqueous solution of irradiated sucrose was found to linearly increase with increasing absorbed dose. Therefore, the EPR and UV results suggest that sucrose can be a useful dosimeter for heavy-ion irradiation. PMID:25480828

  4. Milk iron content in breast-feeding mothers after administration of intravenous iron sucrose complex.

    Science.gov (United States)

    Breymann, Christian; von Seefried, Bettina; Stahel, Michele; Geisser, Peter; Canclini, Camillo

    2007-01-01

    To study the transfer of parenteral iron sucrose into maternal milk in the postpartum period. Ten healthy lactating mothers with functional iron deficiency 2-3 days after delivery received 100 mg intravenous iron sucrose and were observed together with a control group (n=5) without iron treatment during four days. Milk samples were taken before the treatment and every day afterwards. Mean milk iron levels at baseline were 0.43 and 0.46 mg/kg in the treatment and control group and decreased until the end of observation in both groups by 0.11 mg/kg. No significant difference between the groups was found on any study day as well as in the mean change from baseline over all four days. We could not show transfer of iron-sucrose into maternal milk for the given dosage. Since parenteral iron sucrose is widely used in obstetrics, the results provide information about safety of parenteral iron sucrose in the lactation period. The findings are also in agreement with other reports on active biological mammary gland regulation of milk iron concentration.

  5. Responding for sucrose and wheel-running reinforcement: effect of pre-running.

    Science.gov (United States)

    Belke, Terry W

    2006-01-10

    Six male albino Wistar rats were placed in running wheels and exposed to a fixed interval 30-s schedule that produced either a drop of 15% sucrose solution or the opportunity to run for 15s as reinforcing consequences for lever pressing. Each reinforcer type was signaled by a different stimulus. To assess the effect of pre-running, animals were allowed to run for 1h prior to a session of responding for sucrose and running. Results showed that, after pre-running, response rates in the later segments of the 30-s schedule decreased in the presence of a wheel-running stimulus and increased in the presence of a sucrose stimulus. Wheel-running rates were not affected. Analysis of mean post-reinforcement pauses (PRP) broken down by transitions between successive reinforcers revealed that pre-running lengthened pausing in the presence of the stimulus signaling wheel running and shortened pauses in the presence of the stimulus signaling sucrose. No effect was observed on local response rates. Changes in pausing in the presence of stimuli signaling the two reinforcers were consistent with a decrease in the reinforcing efficacy of wheel running and an increase in the reinforcing efficacy of sucrose. Pre-running decreased motivation to respond for running, but increased motivation to work for food.

  6. Biosynthesis of inulin from sucrose using inulosucrase from Lactobacillus gasseri DSM 20604.

    Science.gov (United States)

    Ni, Dawei; Zhu, Yingying; Xu, Wei; Bai, Yuxiang; Zhang, Tao; Mu, Wanmeng

    2018-04-01

    Inulin is composed of fructose residues connected by β-(2, 1) glycosidic linkages with many promising physiochemical and physiological properties. In this study, an inulin-producing inulosucrase gene from Lactobacillus gasseri DSM 20604 was cloned, expressed and purified. SDS-PAGE and gel filtration found that the recombinant inulosucrase is a monomeric protein with a molecular weight of 63KDa. The optimal pH for its sucrose hydrolysis and transfructosylation activities was pH 5.5. The optimal temperatures were measured to be 45, 25, and 35°C for sucrose hydrolysis, transfructosylation, and total activity, respectively. Biosynthesis studies showed that the optimal enzyme dosage was 4.5U/g sucrose. Higher sucrose concentrations immensely contributed to inulin biosynthesis; the inulin yield reached its maximum after 1.5h of reaction. Structural analyses of the polysaccharide produced by the recombinant enzyme from sucrose revealed that it is an inulin-type fructan with a molecular weight of 5.858×10 6 Da. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Cloning and characterization of a Candida albicans maltase gene involved in sucrose utilization.

    Science.gov (United States)

    Geber, A; Williamson, P R; Rex, J H; Sweeney, E C; Bennett, J E

    1992-01-01

    In order to isolate the structural gene involved in sucrose utilization, we screened a sucrose-induced Candida albicans cDNA library for clones expressing alpha-glucosidase activity. The C. albicans maltase structural gene (CAMAL2) was isolated. No other clones expressing alpha-glucosidase activity. were detected. A genomic CAMAL2 clone was obtained by screening a size-selected genomic library with the cDNA clone. DNA sequence analysis reveals that CAMAL2 encodes a 570-amino-acid protein which shares 50% identity with the maltase structural gene (MAL62) of Saccharomyces carlsbergensis. The substrate specificity of the recombinant protein purified from Escherichia coli identifies the enzyme as a maltase. Northern (RNA) analysis reveals that transcription of CAMAL2 is induced by maltose and sucrose and repressed by glucose. These results suggest that assimilation of sucrose in C. albicans relies on an inducible maltase enzyme. The family of genes controlling sucrose utilization in C. albicans shares similarities with the MAL gene family of Saccharomyces cerevisiae and provides a model system for studying gene regulation in this pathogenic yeast. Images PMID:1400249

  8. Role of plaque in the clearance of salivary sucrose and its influence on salivary ph

    Directory of Open Access Journals (Sweden)

    A Kumar

    2011-01-01

    Full Text Available Background: The prevalence of dental caries in children, in India, is higher than many of the industrialized countries. The sugar most commonly associated with dental caries is sucrose, as the microorganisms in the dental plaque have the ability to convert this dietary constituent into various organic acids. Aims and Objectives: This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and to study the effect of the presence of plaque on salivary pH, following sucrose clearance. Materials and Methods: Salivary sucrose determination was done by using the anthrone technique. A Digital MHOS pH meter estimated the salivary pH. Results: Presence of plaque increased the salivary sucrose clearance time and decreased the salivary pH at various time intervals. Conclusions: The microbial etiology of dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and pH lowering, and the cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

  9. Effects of elevated carbon dioxide and sucrose concentrations on Arabidopsis thaliana root architecture and anatomy

    International Nuclear Information System (INIS)

    Lee-Ho, E.; Walton, L.J.; Reid, D.M.; Yeung, E.C.; Kurepin, L.V.

    2007-01-01

    Plant root growth is known to be influenced by higher levels of atmospheric carbon dioxide (CO 2 ). Roots of some species grown in hydroponics under elevated CO 2 concentrations may be more competitive sinks for photosynthetic assimilates than roots grown under lower CO 2 conditions. Root branching patterns may also be influenced by elevated CO 2 concentrations. Studies have also shown that factors such as soil compaction, salinity and the availability of nitrate, phosphorous, oxygen and water also influence root growth, and the effects of higher CO 2 on roots can be confounded by such environmental factors. This study evaluated the effects of elevated carbon dioxide and sucrose concentrations on Arabidopsis thaliana root growth, morphology, and architecture. Both ambient and elevated CO 2 levels were used along with various sucrose concentrations. The study revealed that A. thaliana plants grown on a phytagar medium in small chambers with elevated CO 2 had longer roots, more lateral root growth than plants grown in ambient CO 2 . Roots in elevated CO 2 were found to have wider root diameters, and more secondary growth. The addition of sucrose to the media closely resembled the effects of elevated CO 2 . In addition, the increase in sucrose concentration had a bigger effect on root morphology under ambient, than elevated CO 2 . Therefore, both elevated CO 2 and increased sucrose concentrations promote root growth by increasing their number, length, and diameter. The dichotomy branching index (DBI) also dropped resulting in a more dichotomous branching pattern. 34 refs., 5 figs

  10. Electrical stimulation of the lateral habenula produces an inhibitory effect on sucrose self-administration.

    Science.gov (United States)

    Friedman, Alexander; Lax, Elad; Dikshtein, Yahav; Abraham, Lital; Flaumenhaft, Yakov; Sudai, Einav; Ben-Tzion, Moshe; Yadid, Gal

    2011-01-01

    The lateral habenula (LHb) plays a role in prediction of negative reinforcement, punishment and aversive responses. In the current study, we examined the role that the LHb plays in regulation of negative reward responses and aversion. First, we tested the effect of intervention in LHb activity on sucrose reinforcing behavior. An electrode was implanted into the LHb and rats were trained to self-administer sucrose (20%; 16 days) until at least three days of stable performance were achieved (as represented by the number of active lever presses in self-administration cages). Rats subsequently received deep brain stimulation (DBS) of the LHb, which significantly reduced sucrose self-administration levels. In contrast, lesion of the LHb increased sucrose-seeking behavior, as demonstrated by a delayed extinction response to substitution of sucrose with water. Furthermore, in a modified non-rewarding conditioned-place-preference paradigm, DBS of the LHb led to aversion to the context associated with stimulation of this brain region. We postulate that electrical stimulation of the LHb attenuates positive reward-associated reinforcement by natural substances. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. ESR investigation of L-α-alanine and sucrose radicals produced by heavy-ion irradiation

    International Nuclear Information System (INIS)

    Nakagawa, K.; Sato, Y.

    2005-01-01

    We investigated sucrose and L-α-alanine radicals produced by heavy (particle) ion irradiation with various LETs (linear energy transfer). The impact of the heavy ions on the samples produced stable free radicals, which were analyzed by ESR (electron spin resonance). Identical spectra were measured after one year. The obtained spectral patterns were the same as those for helium (He), carbon (C), and neon (Ne) ions irradiation. The absorbed dose dependences for the irradiated sucrose and alanine samples were examined. The ESR response has a linear relation with the absorbed dose. The ESR response at 60 Gy was slightly lower than a linear line for sucrose; however, the response showed good linearity for the alanine. In addition, the total spin concentration obtained by heavy-ion irradiation correlated logarithmically with the LET. Qualitative ESR analyse showed that the production of sucrose and alanine radicals depended on both different particle irradiation and the LET under the same dose. Thus, the present ESR results imply that sucrose together with L-α-alanine can be used to monitor LET as well as the number of ionizing particle for the production of stable free radicals. (author)

  12. The effects of sucrose on the mechanical properties of acid milk proteins-kappa-carrageenan gels

    Directory of Open Access Journals (Sweden)

    E. Sabadini

    2006-03-01

    Full Text Available Mechanical properties have been widely correlated with textural characteristics to determine the interactions during the process formation of dairy gel. These interactions are strongly affected by process conditions and system composition. In the present study, the rheological of acid-induced protein dairy gels with (2(7-3 and without (2(6-2 sucrose and subjected to small and large deformations were studied using an experimental design. The independent variables were the sodium caseinate, whey protein concentrate (WPC, carrageenan and sucrose concentrations as well as stirring speed and heat treatment time and temperature. Mechanical deformation tests were performed at 0.1, 1, 5, and 9 mm/s up to 80% of initial height. A heavy dependence of rupture stress on increasing crosshead speed and the formation of harder gels with the addition of sucrose were observed. Moreover the elastic and viscous moduli, obtained by fitting the Maxwell model to stress relaxation data, increased with increasing addition of sucrose. These results can be explained by preferential hydration of the casein with sucrose, causing an induction of casein-polysaccharide and casein-casein interactions.

  13. Antisense repression of sucrose phosphate synthase in transgenic muskmelon alters plant growth and fruit development

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Hongmei; Ma, Leyuan; Zhao, Cong; Hao, Hui; Gong, Biao [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai' an, Shandong 271018 (China); Yu, Xiyan, E-mail: yuxiyan@sdau.edu.cn [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai' an, Shandong 271018 (China); Wang, Xiufeng, E-mail: xfwang@sdau.edu.cn [College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai' an, Shandong 271018 (China)

    2010-03-12

    To unravel the roles of sucrose phosphate synthase (SPS) in muskmelon (Cucumis melo L.), we reduced its activity in transgenic muskmelon plants by an antisense approach. For this purpose, an 830 bp cDNA fragment of muskmelon sucrose phosphate synthase was expressed in antisense orientation behind the 35S promoter of the cauliflower mosaic virus. The phenotype of the antisense plants clearly differed from that of control plants. The transgenic plant leaves were markedly smaller, and the plant height and stem diameter were obviously shorter and thinner. Transmission electron microscope observation revealed that the membrane degradation of chloroplast happened in transgenic leaves and the numbers of grana and grana lamella in the chloroplast were significantly less, suggesting that the slow growth and weaker phenotype of transgenic plants may be due to the damage of the chloroplast ultrastructure, which in turn results in the decrease of the net photosynthetic rate. The sucrose concentration and levels of sucrose phosphate synthase decreased in transgenic mature fruit, and the fruit size was smaller than the control fruit. Together, our results suggest that sucrose phosphate synthase may play an important role in regulating the muskmelon plant growth and fruit development.

  14. Dietary sucrose and starch affect dysplastic characteristics in carcinogen-induced aberrant crypt foci in rat colon.

    Science.gov (United States)

    Caderni, G; Lancioni, L; Luceri, C; Giannini, A; Lodovici, M; Biggeri, A; Dolara, P

    1997-03-19

    To study whether dietary carbohydrates affect dysplasia in aberrant crypt foci (ACF), rats treated with 1,2-dimethilhydrazine (DMH) were fed for three months with diets containing 46% sucrose or corn starch. The number of ACF/colon in the two dietary groups was similar (P = 0.58), but ACF were smaller in the starch than in sucrose group (P colon carcinogenesis while sucrose in the diet is detrimental, promoting the dysplasia of preneoplastic lesions like ACF.

  15. Evaluation of the risk of fungal spoilage when substituting sucrose with commercial purified Stevia glycosides in sweetened bakery products.

    Science.gov (United States)

    Rodríguez, Alicia; Magan, Naresh; Medina, Angel

    2016-08-16

    The objectives of this study were to compare the effect of different Stevia-based sugar substitutes (S1-S3), sucrose alone and a mixture of sucrose+S1 on: (a) humectant properties, (b) relative colonisation rates of sponge cake slices at 0.90 aw by strains of Aspergillus flavus, Eurotium amstelodami, Fusarium graminearum and Penicillium verrucosum at 20 and 25°C and (c) shelf-life periods in days prior to visible growth. Results showed that sucrose, S1 commercial sugar substitute and the mixture of sucrose+S1 in water solutions were able to reach water activity levels similar to those of glycerol and glucose mixtures. The S2 and S3 commercial sugar substitutes were unable to reduce aw levels significantly. At 25°C, colonisation of sponge cake slices by E. amstelodami, A. flavus and P. verrucosum occurred in all the treatments. Growth of F. graminearum only occurred on sponge cake slices containing S2 and S3 Stevia-based products at both temperatures. The best control of growth (30days) was achieved in cake slices modified with sucrose or S1 Stevia treatments inoculated with A. flavus and in the sucrose treatment for E. amstelodami at 20°C. F. graminearum growth was completely inhibited when sucrose alone, S1 or sucrose+S1 treatments were used at both temperatures. This study suggests that, as part of a hurdle technology approach, replacing sucrose with low calorie sugar substitutes based on Stevia glycosides needs to be done with care. This is because different products may have variable humectant properties and bulking agents which may shorten the potential shelf-life of intermediate moisture bakery products. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Evaluation of antidiabetic property of Andrographis paniculata powder in high fat and sucrose-induced type-2 diabetic adult male rat

    Directory of Open Access Journals (Sweden)

    Anne Williams Augustine

    2014-02-01

    Full Text Available Objective: To evaluate the antidiabetic effect of the aerial part of Andrographis paniculata (A. paniculata powder (500 mg/kg body weight in high fat and sucrose-induced type-2 diabetic rat model. Methods: The fasting blood glucose, oral glucose tolerance test, serum insulin, lipid profile, mRNA and protein levels of insulin signaling molecules, 14C-2 deoxy glucose uptake and 14C glucose oxidation in liver were checked. Results: In the type-2 diabetes-induced group, the fasting blood glucose, oral glucose tolerance, serum insulin, lipid profile, glucose uptake and oxidation, Akt and glucose transporter 2 mRNA, insulin receptor and glucose transporter 2 protein (both cytosolic and plasma membrane and phosphorylation of insulin receptor substrate 1 and Akt were impaired. A. paniculata was able to successfully reinstate this impairment. In addition to this, A. paniculata did not cause a hypoglycemic condition in normal rat, affirming its activity in hyperglycemic state alone. Conclusions: A. paniculata possesses significant antidiabetic and antihyperlipidemic activities in high fat and sucrose-induced type-2 diabetic rat and the molecular actions at the level of insulin signaling molecules in liver reinforce it.

  17. ZIFL1.1 transporter modulates polar auxin transport by stabilizing membrane abundance of multiple PINs in Arabidopsis root tip

    Science.gov (United States)

    Remy, Estelle; Baster, Pawel; Friml, Jiří; Duque, Paula

    2013-01-01

    Cell-to-cell directional flow of the phytohormone auxin is primarily established by polar localization of the PIN auxin transporters, a process tightly regulated at multiple levels by auxin itself. We recently reported that, in the context of strong auxin flows, activity of the vacuolar ZIFL1.1 transporter is required for fine-tuning of polar auxin transport rates in the Arabidopsis root. In particular, ZIFL1.1 function protects plasma-membrane stability of the PIN2 carrier in epidermal root tip cells under conditions normally triggering PIN2 degradation. Here, we show that ZIFL1.1 activity at the root tip also promotes PIN1 plasma-membrane abundance in central cylinder cells, thus supporting the notion that ZIFL1.1 acts as a general positive modulator of polar auxin transport in roots. PMID:23857365

  18. Characterization of sucrose-negative Pasteurella multocida variants, including isolates from large-cat bite wounds

    DEFF Research Database (Denmark)

    Christensen, Henrik Grimmig; Bisgaard, Magne; Angen, Øystein

    2005-01-01

    To validate the identification of Pasteurella multocida-like bacteria negative for acid formation from sucrose, including isolates from bite wounds caused by large cats, 17 strains were phenotypically and genotypically characterized. Phylogenetic analysis of partially sequenced rpoB and infB genes...... showed the monophyly of the strains characterized and the reference strains of P. multocida. The sucrose-negative strains formed two groups, one related to reference strains of P. multocida and the other related to a separate species-like group (taxon 45 of Bisgaard). DNA-DNA hybridization further...... and the reference strains of P. multocida. Two strains isolated from leopard bite wounds were related to the type strain of P. dagmatis; however, they represented a new taxon (taxon 46 of Bisgaard), in accordance with their distinct phenotypic and genotypic identifications. The present study documents that sucrose-negative...

  19. Impact of sucrose contents and cooking time on cowpea prices in Senegal

    Directory of Open Access Journals (Sweden)

    Mb.D Faye

    2014-07-01

    Full Text Available An alternative approach to traditional consumer behaviour and demand theory is characteristics theory, which assumes that a consumer’s utility function is generated by the characteristics, or attributes, that goods and services possess. Instead of a utility being a function of a product, it becomes a function of the attributes provided by these products. In this paper a hedonic pricing model is used to investigate the influence of sucrose level and cooking time on cowpea prices in Senegal.  Cooking time has a significant impact on price only at Tilene market in Dakar, while the sucrose contents tend to provide a premium throughout. Further investigation shows that the local varieties, AW, Matam and Ndiassiw have higher sucrose contents than the other cowpea varieties.

  20. Expression, purification and preliminary crystallographic analysis of sucrose phosphate synthase (SPS) from Halothermothrix orenii

    International Nuclear Information System (INIS)

    Huynh, Frederick; Tan, Tien-Chye; Swaminathan, Kunchithapadam; Patel, Bharat K. C.

    2004-01-01

    The first crystallographic study of a sucrose phosphate synthase from H. orenii, an organism that is both thermophilic and halophilic, is reported. The protein crystal diffracts X-rays to 3.01 Å. This is the first report of the crystallization of a sucrose phosphate synthase (SPS; EC 2.4.1.14). It also constitutes the first study of a sucrose phosphate synthase from a non-photosynthetic thermohalophilic anaerobic bacterium, Halothermothrix orenii. The purified recombinant spsA protein has been crystallized in the monoclinic space group C2, with unit-cell parameters a = 154.2, b = 47.9, c = 72.3 Å, β = 103.16°, using the hanging-drop vapour-diffusion method. The crystal diffracts X-rays to a resolution limit of 3.01 Å. Heavy-metal and halide-soaking trials are currently in progress to solve the structure

  1. Sucrose, glucose and fructose have similar genotoxicity in the rat colon and affect the metabolism

    DEFF Research Database (Denmark)

    Hansen, Max; Baunsgaard, D.; Autrup, H.

    2008-01-01

    We have shown previously that a high sucrose intake increases the background level of somatic mutations and the level of bulky DNA adducts in the colon epithelium of rats. The mechanism may involve either glucose or fructose formed by hydrolysis of sucrose. Male Big Blue (R) rats were fed 30......% sucrose, glucose, fructose or potato starch as part of the diet. Mutation rates and bulky DNA adduct levels were determined in colon and liver. The concentration of short-chain fatty acids and pH were deter-mined in caecum, C-peptide was determined in plasma, biomarkers for oxidative damage....... The metabonomic studies indicated disturbed amino acid metabolism and decrease in plasma and urinary acetate as a common feature for all sugars and confirmed triglyceridemic effects of fructose. In conclusion, the genotoxicity may be related to the altered chemical environment in the caecum and thereby also...

  2. Solid-phase radioimmunoassay of immunoglobulins G, A and M: applicability in analysis of sucrose gradients

    Energy Technology Data Exchange (ETDEWEB)

    Eriksen, E F; Danielsen, H [Aarhus Kommunehospital (Denmark). Medical Department C; Johansen, A S [Aarhus Univ. (Denmark). Institute of Medical Biochemistry; Larsson, L I [Unit of Histochemistry, University Institute of Pathology, Copenhagen, Denmark

    1984-01-01

    A simple and sensitive solid-phase radioimmunoassay for the detection of immunoglobulins G, A and M in sucrose gradients is described. The solid-phase consisted of immunoglobulins adsorbed to polystyrene tubes. Using buffers without detergent and /sup 125/I-labeled sheep anti-rabbit IgA as radioligand, the assay was able to detect 0.8 ng per tube in the IgG assay and 1.6 ng per tube in the IgA and IgM assays. Standard curves with antigen dissolved in 10% and 32% sucrose were superimposable and did not deviate from standard curves with antigen dissolved in buffer without sucrose. Using these techniques on ultracentrifugation samples from patients with systemic lupus erythematosus, Schoenlein-Henoch nephritis and IgA glorulonephritis is was possible to detect both immunoglobulin fragments and immunoglobulin aggregates at the same time without prior dialysis of the samples.

  3. Transport Statistics - Transport - UNECE

    Science.gov (United States)

    Sustainable Energy Statistics Trade Transport Themes UNECE and the SDGs Climate Change Gender Ideas 4 Change UNECE Weekly Videos UNECE Transport Areas of Work Transport Statistics Transport Transport Statistics About us Terms of Reference Meetings and Events Meetings Working Party on Transport Statistics (WP.6

  4. Ketoprofen and antinociception in hypo-oestrogenic Wistar rats fed on a high sucrose diet.

    Science.gov (United States)

    Jaramillo-Morales, Osmar Antonio; Espinosa-Juárez, Josué Vidal; García-Martínez, Betzabeth Anali; López-Muñoz, Francisco Javier

    2016-10-05

    Non-steroidal anti-inflammatory drugs such as ketoprofen are the most commonly used analgesics for the treatment of pain. However, no studies have evaluated the analgesic response to ketoprofen in conditions of obesity. The aim of this study was to analyse the time course of nociceptive pain in Wistar rats with and without hypo-oestrogenism on a high sucrose diet and to compare the antinociceptive response using ketoprofen. Hypo-oestrogenic and naïve rats received a hyper caloric diet (30% sucrose) or water ad libitum for 17 weeks, the thermal nociception ("plantar test" method) and body weight were tested during this period. A biphasic response was observed: thermal latency decreased in the 4th week (hyperalgesia), while from 12th to 17th week, thermal latency increased (hypoalgesia) in hypo-oestrogenic rats fed with high sucrose diet compared with the hypo-oestrogenic control group. At 4th and 17th weeks, different doses of ketoprofen (1.8-100mg/kg p.o.), were evaluated in all groups. The administration of ketoprofen at 4th and 17th weeks showed dose-dependent effects in the all groups; however, a greater pharmacological efficacy was observed in the 4th week in the hypo-oestrogenic animals that received sucrose. Nevertheless, in all the groups significantly diminish the antinociceptive effects in the 17th week. Our data showed that nociception was altered in the hypo-oestrogenic animals that were fed sucrose (hyperalgesia and hypoalgesia). Ketoprofen showed a dose-dependent antinociceptive effect at both time points. However, hypo-oestrogenism plus high-sucrose diet modifies the antinociceptive effect of ketoprofen. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Effect of sucrose concentrations on Stevia rebaudiana Bertoni tissue culture and gene expression.

    Science.gov (United States)

    Ghorbani, T; Kahrizi, D; Saeidi, M; Arji, I

    2017-08-30

    Stevia rebaudiana (Bert.) Bertoni is known as sweet plant which it contains a high level of steviol glycosides in the leaves.  This plant has been used from centuries ago as a sweetener for tea. One of the most important steviol glycosides is stevioside that is attractive for diabetic persons. Tissue culture is the only rapid process for the mass propagation of stevia. One of the most important factors in the medium is sucrose that is a necessary for plant growth. In the present study, we use nodal segments of the stem as explants in mediums with different sucrose concentration (50 mM, 100mM and 150mM). Several morphological traits were measured in a 28 day period. Results analysis showed a significant variation between treatments. The highest growth rate, rooting and leaf production was obtained in medium with 100mM sucrose. The correlation between measured traits was significant at the 0.01 level. To investigation of UGT74G1, UGT76G1, UGT85C2 and KS genes expression that are involved in the synthesis of SGs, RT- PCR was done with the housekeeping gene of as internal control. There were significant differences between all media. The results showed thatsucrose 100 mM containing media was more desirable than others for expression of UGT76G1 and UGT85C2 genes. Whereas, the best medium for expression of UGT74G1 was sucrose 150 mM and sucrose 50 mM for KS gene. Totally, it seems that sucrose at a concentration of 100 mMprovides the best condition for stevia growth and steviol glycosides production.

  6. Operant licking for intragastric sugar infusions: differential reinforcing actions of glucose, sucrose and fructose in mice

    Science.gov (United States)

    Sclafani, Anthony; Ackroff, Karen

    2015-01-01

    Intragastric (IG) flavor conditioning studies in rodents indicate that isocaloric sugar infusions differ in their reinforcing actions, with glucose and sucrose more potent than fructose. Here we determined if the sugars also differ in their ability to maintain operant self-administration by licking an empty spout for IG infusions. Food-restricted C57BL/6J mice were trained 1 h/day to lick a food-baited spout, which triggered IG infusions of 16% sucrose. In testing, the mice licked an empty spout, which triggered IG infusions of different sugars. Mice shifted from sucrose to 16% glucose increased dry licking, whereas mice shifted to 16% fructose rapidly reduced licking to low levels. Other mice shifted from sucrose to IG water reduced licking more slowly but reached the same low levels. Thus IG fructose, like water, is not reinforcing to hungry mice. The more rapid decline in licking induced by fructose may be due to the sugar's satiating effects. Further tests revealed that the Glucose mice increased their dry licking when shifted from 16% to 8% glucose, and reduced their dry licking when shifted to 32% glucose. This may reflect caloric regulation and/or differences in satiation. The Glucose mice did not maintain caloric intake when tested with different sugars. They self-infused less sugar when shifted from 16% glucose to 16% sucrose, and even more so when shifted to 16% fructose. Reduced sucrose self-administration may occur because the fructose component of the disaccharide reduces its reinforcing potency. FVB mice also reduced operant licking when tested with 16% fructose, yet learned to prefer a flavor paired with IG fructose. These data indicate that sugars differ substantially in their ability to support IG self-administration and flavor preference learning. The same post-oral reinforcement process appears to mediate operant licking and flavor learning, although flavor learning provides a more sensitive measure of sugar reinforcement. PMID:26485294

  7. Vacuolar Protein Sorting Genes in Parkinson's Disease: A Re-appraisal of Mutations Detection Rate and Neurobiology of Disease.

    Science.gov (United States)

    Gambardella, Stefano; Biagioni, Francesca; Ferese, Rosangela; Busceti, Carla L; Frati, Alessandro; Novelli, Giuseppe; Ruggieri, Stefano; Fornai, Francesco

    2016-01-01

    Mammalian retromers play a critical role in protein trans-membrane sorting from endosome to the trans-Golgi network (TGN). Recently, retromer alterations have been related to the onset of Parkinson's Disease (PD) since the variant p.Asp620Asn in VPS35 (Vacuolar Protein Sorting 35) was identified as a cause of late onset PD. This variant causes a primary defect in endosomal trafficking and retromers formation. Other mutations in VPS genes have been reported in both sporadic and familial PD. These mutations are less defined. Understanding the specific prevalence of all VPS gene mutations is key to understand the relevance of retromers impairment in the onset of PD. A number of PD-related mutations despite affecting different biochemical systems (autophagy, mitophagy, proteasome, endosomes, protein folding), all converge in producing an impairment in cell clearance. This may explain how genetic predispositions to PD may derive from slightly deleterious VPS mutations when combined with environmental agents overwhelming the clearance of the cell. This manuscript reviews genetic data produced in the last 5 years to re-define the actual prevalence of VPS gene mutations in the onset of PD. The prevalence of p.Asp620Asn mutation in VPS35 is 0.286 of familial PD. This increases up to 0.548 when considering mutations affecting all VPS genes. This configures mutations in VPS genes as the second most frequent autosomal dominant PD genotype. This high prevalence, joined with increased awareness of the role played by retromers in the neurobiology of PD, suggests environmentally-induced VPS alterations as crucial in the genesis of PD.

  8. Experimental feeding of Hydrilla verticillata colonized by stigonematales cyanobacteria induces vacuolar myelinopathy in painted turtles (Chrysemys picta.

    Directory of Open Access Journals (Sweden)

    Albert D Mercurio

    Full Text Available Vacuolar myelinopathy (VM is a neurologic disease primarily found in birds that occurs when wildlife ingest submerged aquatic vegetation colonized by an uncharacterized toxin-producing cyanobacterium (hereafter "UCB" for "uncharacterized cyanobacterium". Turtles are among the closest extant relatives of birds and many species directly and/or indirectly consume aquatic vegetation. However, it is unknown whether turtles can develop VM. We conducted a feeding trial to determine whether painted turtles (Chrysemys picta would develop VM after feeding on Hydrilla (Hydrilla verticillata, colonized by the UCB (Hydrilla is the most common "host" of UCB. We hypothesized turtles fed Hydrilla colonized by the UCB would exhibit neurologic impairment and vacuolation of nervous tissues, whereas turtles fed Hydrilla free of the UCB would not. The ability of Hydrilla colonized by the UCB to cause VM (hereafter, "toxicity" was verified by feeding it to domestic chickens (Gallus gallus domesticus or necropsy of field collected American coots (Fulica americana captured at the site of Hydrilla collections. We randomly assigned ten wild-caught turtles into toxic or non-toxic Hydrilla feeding groups and delivered the diets for up to 97 days. Between days 82 and 89, all turtles fed toxic Hydrilla displayed physical and/or neurologic impairment. Histologic examination of the brain and spinal cord revealed vacuolations in all treatment turtles. None of the control turtles exhibited neurologic impairment or had detectable brain or spinal cord vacuolations. This is the first evidence that freshwater turtles can become neurologically impaired and develop vacuolations after consuming toxic Hydrilla colonized with the UCB. The southeastern United States, where outbreaks of VM occur regularly and where vegetation colonized by the UCB is common, is also a global hotspot of freshwater turtle diversity. Our results suggest that further investigations into the effect of the

  9. Silencing of vacuolar invertase and asparagine synthetase genes and its impact on acrylamide formation of fried potato products.

    Science.gov (United States)

    Zhu, Xiaobiao; Gong, Huiling; He, Qunyan; Zeng, Zixian; Busse, James S; Jin, Weiwei; Bethke, Paul C; Jiang, Jiming

    2016-02-01

    Acrylamide is produced in a wide variety of carbohydrate-rich foods during high-temperature cooking. Dietary acrylamide is a suspected human carcinogen, and health concerns related to dietary acrylamide have been raised worldwide. French fries and potato chips contribute a significant proportion to the average daily intake of acrylamide, especially in developed countries. One way to mitigate health concerns related to acrylamide is to develop potato cultivars that have reduced contents of the acrylamide precursors asparagine, glucose and fructose in tubers. We generated a large number of silencing lines of potato cultivar Russet Burbank by targeting the vacuolar invertase gene VInv and the asparagine synthetase genes StAS1 and StAS2 with a single RNA interference construct. The transcription levels of these three genes were correlated with reducing sugar (glucose and fructose) and asparagine content in tubers. Fried potato products from the best VInv/StAS1/StAS2-triple silencing lines contained only one-fifteenth of the acrylamide content of the controls. Interestingly, the extent of acrylamide reduction of the best triple silencing lines was similar to that of the best VInv-single silencing lines developed previously from the same potato cultivar Russet Burbank. These results show that an acrylamide mitigation strategy focused on developing potato cultivars with low reducing sugars is likely to be an effective and sufficient approach for minimizing the acrylamide-forming potential of French fry processing potatoes. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  10. Vacuolar H+ -ATPase c protects glial cell death induced by sodium nitroprusside under glutathione-depleted condition.

    Science.gov (United States)

    Byun, Yu Jeong; Lee, Seong-Beom; Lee, Hwa Ok; Son, Min Jeong; Kim, Ho-Shik; Kwon, Oh-Joo; Jeong, Seong-Whan

    2011-08-01

    We examined the role of the c subunit (ATP6L) of vacuolar H(+) -ATPase and its molecular mechanisms in glial cell death induced by sodium nitroprusside (SNP). ATP6L siRNA-transfected cells treated with SNP showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, but reduction of ATP6L did not affect the regulation of lysosomal pH in analyses with lysosomal pH-dependent fluorescence probes. Photodegraded SNP and ferrous sulfate induced cytotoxicity with the same pattern as that of SNP, but SNAP and potassium cyanide did not show activity. Pretreatment of the transfected cells with deferoxamine (DFO) reduced ROS production and significantly inhibited the cytotoxicity, which indicates that primarily iron rather than nitric oxide or cyanide from SNP contributes to cell death. Involvement of apoptotic processes in the cells was not shown. Pretreatment with JNK or p38 chemical inhibitor significantly inhibited the cytotoxicity, and we also confirmed that the MAPKs were activated in the cells by immunoblot analysis. Significant increase of LC3-II conversion was observed in the cells, and the conversions were inhibited by cotransfection of the MAPK siRNAs and pretreatment with DFO. Introduction of Atg5 siRNA inhibited the cytotoxicity and inhibited the activation of MAPKs and the conversion of LC3. We finally confirmed autophagic cell death and involvement of MAPKs by observation of autophagic vacuoles via electron microscopy. These data suggest that ATP6L has a protective role against SNP-induced autophagic cell death via inhibition of JNK and p38 in GSH-depleted glial cells. Copyright © 2011 Wiley-Liss, Inc.

  11. Vacuolar Protein Sorting Genes in Parkinson's Disease: A Re-appraisal of Mutations Detection Rate and Neurobiology of Disease

    Science.gov (United States)

    Gambardella, Stefano; Biagioni, Francesca; Ferese, Rosangela; Busceti, Carla L.; Frati, Alessandro; Novelli, Giuseppe; Ruggieri, Stefano; Fornai, Francesco

    2016-01-01

    Mammalian retromers play a critical role in protein trans-membrane sorting from endosome to the trans-Golgi network (TGN). Recently, retromer alterations have been related to the onset of Parkinson's Disease (PD) since the variant p.Asp620Asn in VPS35 (Vacuolar Protein Sorting 35) was identified as a cause of late onset PD. This variant causes a primary defect in endosomal trafficking and retromers formation. Other mutations in VPS genes have been reported in both sporadic and familial PD. These mutations are less defined. Understanding the specific prevalence of all VPS gene mutations is key to understand the relevance of retromers impairment in the onset of PD. A number of PD-related mutations despite affecting different biochemical systems (autophagy, mitophagy, proteasome, endosomes, protein folding), all converge in producing an impairment in cell clearance. This may explain how genetic predispositions to PD may derive from slightly deleterious VPS mutations when combined with environmental agents overwhelming the clearance of the cell. This manuscript reviews genetic data produced in the last 5 years to re-define the actual prevalence of VPS gene mutations in the onset of PD. The prevalence of p.Asp620Asn mutation in VPS35 is 0.286 of familial PD. This increases up to 0.548 when considering mutations affecting all VPS genes. This configures mutations in VPS genes as the second most frequent autosomal dominant PD genotype. This high prevalence, joined with increased awareness of the role played by retromers in the neurobiology of PD, suggests environmentally-induced VPS alterations as crucial in the genesis of PD. PMID:27932943

  12. Sucrose-sweetened beverages increase fat storage in the liver, muscle, and visceral fat depot

    DEFF Research Database (Denmark)

    Mærsk, Maria; Sparre, Anita Belza; Stødkilde-Jørgensen, Hans

    2012-01-01

    The consumption of sucrose-sweetened soft drinks (SSSDs) has been associated with obesity, the metabolic syndrome, and cardiovascular disorders in observational and short-term intervention studies. Too few long-term intervention studies in humans have examined the effects of soft drinks.......The consumption of sucrose-sweetened soft drinks (SSSDs) has been associated with obesity, the metabolic syndrome, and cardiovascular disorders in observational and short-term intervention studies. Too few long-term intervention studies in humans have examined the effects of soft drinks....

  13. Sucrose modulates insulin amyloid-like fibril formation: effect on the aggregation mechanism and fibril morphology

    DEFF Research Database (Denmark)

    Marasini, Carlotta; Foderà, Vito; Vestergaard, Bente

    2017-01-01

    the protein self-assembly pathways. Using a combination of fluorescence spectroscopy, synchrotron radiation circular dichroism and transmission electron microscopy, we study the kinetics of formation and structural properties of human insulin fibrils in the presence of sucrose. The presence of sucrose results...... in a delay of the onset of fibrillation. Moreover, it leads to a dramatic change in both the morphology and overall amount of fibrils. Our results emphasize that the detailed composition of protein surroundings likely influences not only the fibrillation kinetics but also the balance between different...

  14. Mortality of Bemisia tabaci biotype B (sternorrhyncha: aleyrodidae adults by aliphatic and aromatic synthetic sucrose esters

    Directory of Open Access Journals (Sweden)

    Mariangela Alves

    2008-12-01

    Full Text Available The B-strain of Bemisia tabaci Gennadius is a key pest of several crops and chemical control is the main control method used by growers, although reduction in efficacy due to insecticide resistance has already been reported. The aim of this work was to investigate the insecticidal effect of an array of synthetic sucrose esters with the aliphatic and aromatic groups on whitefly adults. Sucrose butyrate, caprate, octanoate, palmitate, oleate, octaacetate, phthalate, benzoate, and sucrose diacetate hexaisobutyrate were tested. The solutions were prepared and applied on the adults caught on yellow sticky traps using the Potter spray tower. Long-chains sucrose aliphatic esters were more effective against the silverleaf whiteflies and the highest mortality was obtained with sucrose oleate and sucrose octanoate. Since these compounds were tensoactive, sodium dodecylsulphate was also tested for the comparison but no effect was observed. Sucrose butyrate and other aliphatic and aromatic sucrose polyesters showed negligible effect on the silverleaf whiteflies.O biótipo B de B. tabaci Gennadius tem se destacado como uma praga-chave de diversas culturas. O controle químico tem sido a principal tática de controle utilizada, embora já se tenha observado redução na eficiência dos produtos devido ao desenvolvimento de resistência. Assim, o objetivo do presente trabalho foi avaliar o efeito de diversos ésteres de sacarose com grupos alifáticos ou aromáticos sobre adultos de mosca-branca. Butirato de sacarose, caprato, octanoato, palmitato, oleato, actaacetato, ftlato, benzoato e diacetato hexaisobutirato de sacarose foram testados. Soluções de éster de sacarose foram preparadas e aplicadas sobre adultos capturados em armadilhas adesivas utilizando Torre de Potter. Ésteres alifáticos de sacarose com longas cadeias foram mais efetivos contra mosca-branca e as maiores taxas de mortalidade foram obtidas com oleato e octanoato de sacarose. Uma vez que

  15. In vivo survival of [14C]sucrose-loaded porcine carrier erythrocytes

    International Nuclear Information System (INIS)

    DeLoach, J.R.

    1983-01-01

    Porcine carrier erythrocyte survival was measured in adult pigs. [14C]Sucrose-loaded erythrocytes had a biphasic survival curve, with as much as 50% of the cells removed from circulation in the first 24 hours. The remaining cells had a 35-day half-life. Encapsulation values were measured for porcine erythrocytes and entrapment of [14C]sucrose was greater than 45%. Addition of inosine and glucose to the dialyzed cells and to the final wash buffer before reinjection of autologous cells did not improve their survival

  16. ERG2 and ERG24 Are Required for Normal Vacuolar Physiology as Well as Candida albicans Pathogenicity in a Murine Model of Disseminated but Not Vaginal Candidiasis.

    Science.gov (United States)

    Luna-Tapia, Arturo; Peters, Brian M; Eberle, Karen E; Kerns, Morgan E; Foster, Timothy P; Marrero, Luis; Noverr, Mairi C; Fidel, Paul L; Palmer, Glen E

    2015-10-01

    Several important classes of antifungal agents, including the azoles, act by blocking ergosterol biosynthesis. It was recently reported that the azoles cause massive disruption of the fungal vacuole in the prevalent human pathogen Candida albicans. This is significant because normal vacuolar function is required to support C. albicans pathogenicity. This study examined the impact of the morpholine antifungals, which inhibit later steps of ergosterol biosynthesis, on C. albicans vacuolar integrity. It was found that overexpression of either the ERG2 or ERG24 gene, encoding C-8 sterol isomerase or C-14 sterol reductase, respectively, suppressed C. albicans sensitivity to the morpholines. In addition, both erg2Δ/Δ and erg24Δ/Δ mutants were hypersensitive to the morpholines. These data are consistent with the antifungal activity of the morpholines depending upon the simultaneous inhibition of both Erg2p and Erg24p. The vacuoles within both erg2Δ/Δ and erg24Δ/Δ C. albicans strains exhibited an aberrant morphology and accumulated large quantities of the weak base quinacrine, indicating enhanced vacuolar acidification compared with that of control strains. Both erg mutants exhibited significant defects in polarized hyphal growth and were avirulent in a mouse model of disseminated candidiasis. Surprisingly, in a mouse model of vaginal candidiasis, both mutants colonized mice at high levels and induced a pathogenic response similar to that with the controls. Thus, while targeting Erg2p or Erg24p alone could provide a potentially efficacious therapy for disseminated candidiasis, it may not be an effective strategy to treat vaginal infections. The potential value of drugs targeting these enzymes as adjunctive therapies is discussed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. The assembly of metals chelation by thiols and vacuolar compartmentalization conferred increased tolerance to and accumulation of cadmium and arsenic in transgenic Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Guo, Jiangbo; Xu, Wenzhong; Ma, Mi

    2012-01-01

    Highlights: ► Simultaneous transformation of AsPCS1 and ScYCF1 into Arabidopsis thaliana which is sensitive to heavy metals, leads to transgenic plants tolerant to Arsenic and cadmium. ► Dual-gene transgenic Arabidopsis showed higher accumulation of Arsenic and cadmium than single and non-transgenic plants. ► Our results proved that improved thiol peptides synthesis and vacuolar compartmentation in plant dramatically boosted the survival rates of plants when exposed to heavy metals. ► A new strategy for efficient phytoremediation of heavy metals by stacking genes transformation in plants was developed in this article. - Abstract: Transgenic Arabidopsis thaliana were developed to increase tolerance for and accumulation of heavy metals and metalloids by simultaneous overexpression of AsPCS1 and YCF1 (derived from garlic and baker's yeast) based on the fact that chelation of metals and vacuolar compartmentalization are the main strategies for heavy metals/metalloids detoxification and tolerance in plants. Dual-gene transgenic lines had the longest roots and the highest accumulation of Cd and As than single-gene transgenic lines and wildtype. When grown on cadmium or arsenic (arsenite/arsenate), Dual-gene transgenic lines accumulated over 2–10 folds cadmium/arsenite and 2–3 folds arsenate than wild type or plants expressing AsPCS1 or YCF1 alone. Such stacking modified genes involved in chelation of toxic metals and vacuolar compartmentalization represents a highly promising new tool for use in phytoremediation efforts.

  18. Pollination in Nicotiana alata stimulates synthesis and transfer to the stigmatic surface of NaStEP, a vacuolar Kunitz proteinase inhibitor homologue.

    Science.gov (United States)

    Busot, Grethel Yanet; McClure, Bruce; Ibarra-Sánchez, Claudia Patricia; Jiménez-Durán, Karina; Vázquez-Santana, Sonia; Cruz-García, Felipe

    2008-01-01

    After landing on a wet stigma, pollen grains hydrate and germination generally occurs. However, there is no certainty of the pollen tube growth through the style to reach the ovary. The pistil is a gatekeeper that evolved in many species to recognize and reject the self-pollen, avoiding endogamy and encouraging cross-pollination. However, recognition is a complex process, and specific factors are needed. Here the isolation and characterization of a stigma-specific protein from N. alata, NaStEP (N. alata Stigma Expressed Protein), that is homologous to Kunitz-type proteinase inhibitors, are reported. Activity gel assays showed that NaStEP is not a functional serine proteinase inhibitor. Immunohistochemical and protein blot analyses revealed that NaStEP is detectable in stigmas of self-incompatible (SI) species N. alata, N. forgetiana, and N. bonariensis, but not in self-compatible (SC) species N. tabacum, N. plumbaginifolia, N. benthamiana, N. longiflora, and N. glauca. NaStEP contains the vacuolar targeting sequence NPIVL, and immunocytochemistry experiments showed vacuolar localization in unpollinated stigmas. After self-pollination or pollination with pollen from the SC species N. tabacum or N. plumbaginifolia, NaStEP was also found in the stigmatic exudate. The synthesis and presence in the stigmatic exudate of this protein was strongly induced in N. alata following incompatible pollination with N. tabacum pollen. The transfer of NaStEP to the stigmatic exudate was accompanied by perforation of the stigmatic cell wall, which appeared to release the vacuolar contents to the apoplastic space. The increase in NaStEP synthesis after pollination and its presence in the stigmatic exudates suggest that this protein may play a role in the early pollen-stigma interactions that regulate pollen tube growth in Nicotiana.

  19. The assembly of metals chelation by thiols and vacuolar compartmentalization conferred increased tolerance to and accumulation of cadmium and arsenic in transgenic Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiangbo [Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093 (China); Inner Mongolia Key Laboratory of Biomass-Energy Conversion, The Institute of Bioengineering and Technology, Inner Mongolia University of Science and Technology, Baotou 040100 (China); Xu, Wenzhong [Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093 (China); Ma, Mi, E-mail: mami@ibcas.ac.cn [Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Simultaneous transformation of AsPCS1 and ScYCF1 into Arabidopsis thaliana which is sensitive to heavy metals, leads to transgenic plants tolerant to Arsenic and cadmium. Black-Right-Pointing-Pointer Dual-gene transgenic Arabidopsis showed higher accumulation of Arsenic and cadmium than single and non-transgenic plants. Black-Right-Pointing-Pointer Our results proved that improved thiol peptides synthesis and vacuolar compartmentation in plant dramatically boosted the survival rates of plants when exposed to heavy metals. Black-Right-Pointing-Pointer A new strategy for efficient phytoremediation of heavy metals by stacking genes transformation in plants was developed in this article. - Abstract: Transgenic Arabidopsis thaliana were developed to increase tolerance for and accumulation of heavy metals and metalloids by simultaneous overexpression of AsPCS1 and YCF1 (derived from garlic and baker's yeast) based on the fact that chelation of metals and vacuolar compartmentalization are the main strategies for heavy metals/metalloids detoxification and tolerance in plants. Dual-gene transgenic lines had the longest roots and the highest accumulation of Cd and As than single-gene transgenic lines and wildtype. When grown on cadmium or arsenic (arsenite/arsenate), Dual-gene transgenic lines accumulated over 2-10 folds cadmium/arsenite and 2-3 folds arsenate than wild type or plants expressing AsPCS1 or YCF1 alone. Such stacking modified genes involved in chelation of toxic metals and vacuolar compartmentalization represents a highly promising new tool for use in phytoremediation efforts.

  20. Activity of enzymes that hydrolyze sucrose and raffinose in the first stages of germination of Lactuca sativa cv. Grand rapids. [Invertase, alpha-galactosidose, and sucrose synthetase were observed

    Energy Technology Data Exchange (ETDEWEB)

    Slabnik, E.; Calderon, P.; Diaz, H.

    1981-01-01

    The activities of enzymes capable of metabolizing raffinose and sucrose on achenes of lettuce were studied. During the first stages of germination, evidence was obtained for the occurrence of invertase in the endosperm and embryonic axis. Alpha-galactosidase was localized in the endosperm and cotyledons. Sucrose synthetase was present in the dry seed.

  1. Hexoses as phloem transport sugars: the end of a dogma?

    Science.gov (United States)

    van Bel, Aart J E; Hess, Paul H

    2008-01-01

    According to most textbooks, only non-reducing carbohydrate species such as sucrose, sugar alcohols, and raffinose-family sugars function as phloem translocates. Occasional abundance of reducing sugar species (such as hexoses) in sieve-tube sap has been discarded as an experimental artefact. This study, however, discloses a widespread occurrence of hexoses in the sieve-tube sap. Phloem exudation facilitated by EDTA provided evidence that many of the members of two plant families (Ranunculaceae and Papaveraceae) investigated translocate >80% of carbohydrates in the form of hexoses. Representatives of other families also appear to translocate appreciable amounts of hexoses in the sieve tubes. Promoting effects of EDTA, activities of sucrose-degrading enzymes, and sugar uptake by micro-organisms on hexose contents of phloem exudates were checked. The rate of sucrose degradation is far too low to explain the large proportions of hexoses measured in phloem exudates; nor did other factors tested seem to stimulate the occurrence of hexoses. The validity of the approach is further supported by the virtual absence of hexoses in exudates from species that were known as exclusive sucrose transporters. This study urges a rethink of the existing views on carbohydrate transport species in the phloem stream. Hexose translocation is to be regarded as a normal mode of carbohydrate transfer by the phloem equivalent to that of sucrose, raffinose-family sugars, or sugar alcohols.

  2. [Effect of exogenous sucrose on growth and active ingredient content of licorice seedlings under salt stress conditions].

    Science.gov (United States)

    Liu, Fu-zhi; Yang, Jun

    2015-11-01

    Licorice seedlings were taken as experimental materials, an experiment was conducted to study the effects of exogenous sucrose on growth and active ingredient content of licorice seedlings under NaCl stress conditions. The results of this study showed that under salt stress conditions, after adding a certain concentration of exogenous sucrose, the licorice seedlings day of relative growth rate was increasing, and this stress can be a significant weakening effect, indicating that exogenous sucrose salt stress-relieving effect. The total flavonoids and phenylalanine ammonia lyase (PAL) activity were significantly increased, the exogenous sucrose can mitigated the seedling roots under salt stress, the licorice flavonoid content in the enhanced growth was largely due to the activity of PAL an increased, when the concentration of exogenous sucrose wae 10 mmol x L(-1), PAL activity reaching a maximum, when the concentration of exogenous sucrose was 15 mmol x L(-1), PAL activity turned into a downward trend, the results indicating that this mitigation has concentration effect. After applying different concentrations of exogenous sugar, the contents of liquiritin changes with the change of flavonoids content was similar. After applying different concentrations of exogenous sucrose, the content of licorice acid under salt stress was higher than the levels were not reached during salt stress, the impact of exogenous sucrose concentration gradient of licorice acid accumulation was not obvious.

  3. The non-metabolizable sucrose analog sucralose is a potent inhibitor of hormogonium differentiation in the filamentous cyanobacterium Nostoc punctiforme.

    Science.gov (United States)

    Splitt, Samantha D; Risser, Douglas D

    2016-03-01

    Nostoc punctiforme is a filamentous cyanobacterium which forms nitrogen-fixing symbioses with several different plants and fungi. Establishment of these symbioses requires the formation of motile hormogonium filaments. Once infected, the plant partner is thought to supply a hormogonium-repressing factor (HRF) to maintain the cyanobacteria in a vegetative, nitrogen-fixing state. Evidence implies that sucrose may serve as a HRF. Here, we tested the effects of sucralose, a non-metabolizable sucrose analog, on hormogonium differentiation. Sucralose inhibited hormogonium differentiation at a concentration approximately one-tenth that of sucrose. This result implies that: (1) sucrose, not a sucrose catabolite, is perceived by the cell and (2) inhibition is not due to a more general osmolarity-dependent effect. Additionally, both sucrose and sucralose induced the accrual of a polysaccharide sheath which bound specifically to the lectin ConA, indicating the presence of α-D-mannose and/or α-D-glucose. A ConA-specific polysaccharide was also found to be expressed in N. punctiforme colonies from tissue sections of the symbiotically grown hornwort Anthoceros punctatus. These findings imply that plant-derived sucrose or sucrose analogs may have multiple effects on N. punctiforme, including both repression of hormogonia and the induction of a polysaccharide sheath that may be essential to establish and maintain the symbiotic state.

  4. Daily Access to Sucrose Impairs Aspects of Spatial Memory Tasks Reliant on Pattern Separation and Neural Proliferation in Rats

    Science.gov (United States)

    Reichelt, Amy C.; Morris, Margaret J.; Westbrook, Reginald Frederick

    2016-01-01

    High sugar diets reduce hippocampal neurogenesis, which is required for minimizing interference between memories, a process that involves "pattern separation." We provided rats with 2 h daily access to a sucrose solution for 28 d and assessed their performance on a spatial memory task. Sucrose consuming rats discriminated between objects…

  5. Examining the side effects of sucrose for pain relief in preterm infants: a case-control study

    Directory of Open Access Journals (Sweden)

    M.B.M. Linhares

    2014-06-01

    Full Text Available Sucrose solution is recommended as relevant pain relief management in neonates during acute painful procedures; however, only a few studies have analyzed the potentially adverse effects of sucrose administration to preterm neonates. The goal of this study was to examine the potential side effects of sucrose for pain relief in preterm infants, assessing feeding and weight gain during hospitalization and their feeding patterns postdischarge. The study sample consisted of 43 preterm neonates divided into two groups: a sucrose group (SG, n=18 and a control group (CG, n=25 in which no sucrose was administered. The SG received 0.5 mL/kg 25% oral sucrose for 2 min prior to all acute painful procedures during three consecutive days. A prospective review of medical charts was performed for all samples. The study was done prior to implementation of the institutional sucrose guidelines as a routine service, and followed all ethical requirements. There were no statistically significant differences between groups in terms of weight gain, length of stay with orogastric tubes, and parenteral feeding. Postdischarge, infant nutritional intake included feeding human milk to 67% of the SG and 74% of the CG. There were no statistically significant differences between groups regarding human milk feeding patterns postdischarge. Neonate feeding patterns and weight gain were unaffected following the short-term use of sucrose for pain relief.

  6. Chronic sucrose intake decreases concentrations of n6 fatty acids, but not docosahexaenoic acid in the rat brain phospholipids.

    Science.gov (United States)

    Mašek, Tomislav; Starčević, Kristina

    2017-07-13

    We investigated the influence of high sucrose intake, administered in drinking water, on the lipid profile of the brain and on the expression of SREBP1c and Δ-desaturase genes. Adult male rats received 30% sucrose solution for 20 weeks (Sucrose group), or plain water (Control group). After the 20th week of sucrose treatment, the Sucrose group showed permanent hyperglycemia. Sucrose treatment also increased the amount of total lipids and fatty acids in the brain. The brain fatty acid profile of total lipids as well as phosphatidylethanolamine, phosphatidylcholine and cardiolipin of the Sucrose group was extensively changed. The most interesting change was a significant decrease in n6 fatty acids, including the important arachidonic acid, whereas the content of oleic and docosahexaenoic acid remained unchanged. RT-qPCR revealed an increase in Δ-5-desaturase and SREBP1c gene expression. In conclusion, high sucrose intake via drinking water extensively changes rat brain fatty acid profile by decreasing n6 fatty acids, including arachidonic acid. In contrast, the content of docosahexaenoic acid remains constant in the brain total lipids as well as in phospholipids. Changes in the brain fatty acid profile reflect changes in the lipid metabolism of the rat lipogenic tissues and concentrations in the circulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Retention of Viability of Salmonella in Sucrose as Affected by Type of Inoculum, Water Activity, and Storage Temperature.

    Science.gov (United States)

    Beuchat, Larry R; Mann, David A; Kelly, Christine A; Ortega, Ynes R

    2017-09-01

    Outbreaks of salmonellosis have been associated with consumption of high-sugar, low-water activity (a w ) foods. The study reported here was focused on determining the effect of storage temperature (5 and 25°C) on survival of initially high and low levels of Salmonella in dry-inoculated sucrose (a w 0.26 ± 0.01 to 0.54 ± 0.01) and wet-inoculated sucrose (a w 0.24 ± 0.01 to 0.44 ± 0.04) over a 52-week period. With the exception of dry-inoculated sucrose at a w 0.26, Salmonella survived for 52 weeks in dry- and wet-inoculated sucrose stored at 5 and 25°C. Retention of viability was clearly favored in sucrose stored at 5°C compared with 25°C, regardless of level or type of inoculum or a w . Survival at 5°C was not affected by a w . Initial high-inoculum counts of 5.18 and 5.25 log CFU/g of dry-inoculated sucrose (a w 0.26 and 0.54, respectively) stored for 52 weeks at 5°C decreased by 0.56 and 0.53 log CFU/g; counts decreased by >4.18 and >4.25 log CFU/g in samples stored at 25°C. Inactivation rates in wet-inoculated sucrose were similar to those in dry-inoculated sucrose; however, a trend toward higher persistence of Salmonella in dry- versus wet-inoculated sucrose suggests there was a higher proportion of cells in the wet inoculum with low tolerance to osmotic stress. Survival patterns were similar in sucrose initially containing a low level of Salmonella (2.26 to 2.91 log CFU/g). The pathogen was recovered from low-inoculated sucrose stored at 5°C for 52 weeks regardless of type of inoculum or a w and from dry-inoculated sucrose (a w 0.54) and wet-inoculated sucrose (a w 0.24) stored at 25°C for 12 and 26 weeks, respectively. Results emphasize the importance of preventing contamination of sucrose intended for use as an ingredient in foods not subjected to a treatment that would be lethal to Salmonella.

  8. Synthesis, Characterization and Hexavalent Chromium Adsorption Characteristics of Aluminum- and Sucrose-Incorporated Tobermorite

    Directory of Open Access Journals (Sweden)

    Zhiguang Zhao

    2017-05-01

    Full Text Available Tobermorites were synthesized from the lime-quartz slurries with incorporations of aluminum and sucrose under hydrothermal conditions, and then used for adsorption of Cr(VI. The chemical components, and structural and morphological properties of tobermorite were characterized by X-ray diffraction (XRD, thermogravimetric-differential scanning calorimetry (TG-DSC, Fourier transform infrared spectroscopy (FT-IR, nuclear magnetic resonance (NMR, scanning electron microscopy (SEM, X-ray photoelectron spectroscopic (XPS and N2 adsorption–desorption measurements. The formation and crystallinity of tobermorite could be largely enhanced by adding 2.3 wt.% aluminum hydroxide or 13.3 wt.% sucrose. Sucrose also played a significantly positive role in increasing the surface area. The adsorption performances for Cr(VI were tested using a batch method taking into account the effects of pH, the adsorption kinetics, and the adsorption isotherms. The adsorption capacities of the aluminum- and sucrose-incorporated tobermorites reached up to 31.65 mg/g and 28.92 mg/g, respectively. Thus, the synthesized tobermorites showed good adsorption properties for removal of Cr(VI, making this material a promising candidate for efficient bulk wastewater treatment.

  9. 78 FR 66743 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose; Availability

    Science.gov (United States)

    2013-11-06

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2007-D-0369] Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose; Availability AGENCY... guidance, FDA recommended an in vivo fasting BE study with pharmacokinetic endpoints and in vitro studies...

  10. Biocatalytic Process for Production of α-Glucosylglycerol Using Sucrose Phosphorylase

    Directory of Open Access Journals (Sweden)

    Christiane Luley-Goedl

    2010-01-01

    Full Text Available Glycosylglycerols are powerful osmolytes, produced by various plants, algae and bacteria in adaptation to salt stress and drought. Among them, glucosylglycerol (2-O-α-D-glucopyranosyl-sn-glycerol; GG has attracted special attention for its promising application as a moisturizing agent in cosmetics. A biocatalytic process for the synthesis of GG as industrial fine chemical is described in which sucrose phosphorylase (from Leuconostoc mesenteroides catalyzes regioselective glucosylation of glycerol using sucrose as the donor substrate. The overall enzymatic conversion, therefore, is sucrose+glycerol→GG+D-fructose. Using a twofold molar excess of glycerol acceptor in highly concentrated substrate solution, GG yield was 90 % based on ≥250 g/L of converted sucrose. Enzymatic GG production was implemented on a multihundred kg-per-year manufacturing scale, and a commercial product for cosmetic applications is distributed on the market under the name Glycoin®. Technical features of the biotransformation that were decisive for a successful process development are elaborated. Stabilization of proteins is another interesting field of application for GG.

  11. Semiautomated system for the production and analysis of sucrose density gradients

    International Nuclear Information System (INIS)

    Lange, C.S.; Liberman, D.F.

    1974-01-01

    A semiautomated system in DNA damage studies permitting considerable accuracy, speed, and reproducibility in the making and fractionation of sucrose density gradients is described. The system consists of a modified Beckman gradient forming device that makes six gradients simultaneously and delivers them into six 12.5 ml polyallomer centrifuge tubes in such a manner that new material is continuously added to the meniscus of the gradient. The gradients are fractionated three at a time and up to 100 fractions per gradient can be collected automatically directly into scintillation vials with a choice of drop counting or time mode with rinse and automatic addition of scintillation fluid to each vial. The system can process up to six gradients per hour but centrifugation time is usually the limiting factor. With neutral sucrose gradients, sharp, reproducible, monodisperse peaks containing up to 100 percent of the gradient radioactivity are usually obtained but a smaller monodisperse peak containing as little as 3.5 percent of the gradient radioactivity can be detected under conditions where some pairs of molecules might tangle or dimerize. The resolution and reproducibility of this system when used with neutral sucrose gradients is at least the equal if not superior to that commonly claimed for alkaline sucrose gradients. (U.S.)

  12. Directed shift of vaginal microbiota induced by vaginal application of sucrose gel in rhesus macaques

    Directory of Open Access Journals (Sweden)

    Kai-tao Hu

    2015-04-01

    Conclusions: Rhesus macaques can be used as animal models of bacterial vaginosis to develop drugs and test treatment efficacy. Furthermore, the topical application of sucrose gel induced the shifting of vaginal flora of rhesus macaques from a BV kind of flora to a lactobacilli-dominating flora.

  13. Continuous production of glycerol by catalytic high pressure hydrogenolysis of sucrose

    NARCIS (Netherlands)

    van Ling, Gerrit; Driessen, Alfons J.; Piet, Arie C.; Vlugter, Jozef C.

    1970-01-01

    Several continuous reactor systems have been discussed for the catalytic high pressure hydrogenolysis of sucrose to glycerol. Theoretically and actually, continuous reactors lead to lower glycerol yields than in a batch process. Two continuous stirred tank reactors in cascade constitute a reasonable

  14. Effects of glucose and sucrose on mood: a systematic review of interventional studies

    NARCIS (Netherlands)

    Rest, van de O.; Zwaluw, van der N.L.; Groot, de C.P.G.M.

    2018-01-01

    Context: Glucose is the main energy source for the brain, and as such, manipulation of glucose supply may affect brain function. It has been suggested that a change in blood glucose may influence mood. Objective: The aim of this review was to investigate the potential effects of glucose and sucrose,

  15. Application of diffusion ordered-1H-nuclear magnetic resonance spectroscopy to quantify sucrose in beverages.

    Science.gov (United States)

    Cao, Ruge; Nonaka, Airi; Komura, Fusae; Matsui, Toshiro

    2015-03-15

    This work focuses on a quantitative analysis of sucrose using diffusion ordered-quantitative (1)H-nuclear magnetic resonance spectroscopy (DOSY-qNMR), where an analyte can be isolated from interference based on its characteristic diffusion coefficient (D) in gradient magnetic fields. The D value of sucrose in deuterium oxide at 30°C was 4.9 × 10(-10)m(2)/s at field gradient pulse from 5.0 × 10(-2) to 3.0 × 10(-1)T/m, separated from other carbohydrates (glucose and fructose). Good linearity (r(2)=0.9999) was obtained between sucrose (0.5-20.0 g/L) and the resonance area of target glucopyranosyl-α-C1 proton normalised to that of cellobiose C1 proton (100.0 g/L, as an internal standard) in 1D sliced DOSY spectrum. The DOSY-qNMR method was successfully applied to quantify sucrose in orange juice (36.1 ± 0.5 g/L), pineapple juice (53.5 ± 1.1g/L) and a sports drink (24.7 ± 0.6g/L), in good agreement with the results obtained by an F-kit method. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Overexpression, purification, crystallization and preliminary diffraction studies of the Protaminobacter rubrum sucrose isomerase SmuA

    International Nuclear Information System (INIS)

    Ravaud, Stéphanie; Watzlawick, Hildegard; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2005-01-01

    The P. rubrum sucrose isomerase SmuA, a key enzyme in the industrial production of isomaltulose, was crystallized and diffraction data were collected to 1.95 Å resolution. Palatinose (isomaltulose, α-d-glucosylpyranosyl-1,6-d-fructofuranose), a nutritional and acariogenic reducing sugar, is industrially obtained from sucrose by using immobilized cells of Protaminobacter rubrum that produce the sucrose isomerase SmuA. The isomerization of sucrose catalyzed by this enzyme also results in the formation of trehalulose (α-d-glucosylpyranosyl-1,1-d-fructofuranose) in smaller amounts and glucose, fructose and eventually isomaltose as by-products, which lower the yield of the reaction and complicate the recovery of palatinose. The determination of the three-dimensional structure of SmuA will provide a basis for rational protein-engineering studies in order to optimize the industrial production of palatinose. A recombinant form of the 67.3 kDa SmuA enzyme has been crystallized in the native state by the vapour-diffusion method. Crystals belong to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 61.6, b = 81.4, c = 135.6 Å, and diffract to 1.95 Å resolution on a synchrotron-radiation source

  17. Measurement of Enzyme Kinetics by Use of a Blood Glucometer: Hydrolysis of Sucrose and Lactose

    Science.gov (United States)

    Heinzerling, Peter; Schrader, Frank; Schanze, Sascha

    2012-01-01

    An alternative analytical method for measuring the kinetic parameters of the enzymes invertase and lactase is described. Invertase hydrolyzes sucrose to glucose and fructose and lactase hydrolyzes lactose to glucose and galactose. In most enzyme kinetics studies, photometric methods or test strips are used to quantify the derivates of the…

  18. Social defeat-induced anhedonia: effects on operant sucrose-seeking behavior

    NARCIS (Netherlands)

    Riga, D.; Theijs, J.T.; de Vries, T.J.; Smit, A.B.; Spijker, S.

    2015-01-01

    Reduced capacity to experience pleasure, also known as anhedonia, is a key feature of the depressive state and is associated with poor disease prognosis and treatment outcome. Various behavioral readouts (e.g., reduced sucrose intake) have been employed in animal models of depression as a measure of

  19. Sensory and physicochemical evaluation of acerola nectar sweetened with sucrose and different sweeteners

    Directory of Open Access Journals (Sweden)

    Mariana Borges de Lima Dutra

    2013-12-01

    Full Text Available This paper aims to evaluate the physicochemical characteristics, sensory acceptance, and purchase intent of acerola nectar sweetened with sucrose and other sweeteners (neotame, sucralose and stevia extracts with 40%, 60%, 80%, and 95% rebaudioside A. The analyses were carried out for pH, soluble solids, total titratable acidity, ascorbic acid, and colorimetry (L*a*b. The acceptance test was performed by 120 consumers who evaluated the appearance, aroma, flavor, texture, and overall impression of the samples using a 9-cm unstructured hedonic scale. Furthermore, the consumers were asked to rate overall purchase intent along the scale anchored with (1 "would definitely not purchase" to (5 "would definitely purchase." The results were evaluated using analysis of variance/Tukey test and the internal preference mapping technique. The acerola nectar samples did not differ significantly (p>0.05 between themselves in terms of vitamin C content and total titratable acidity. As for appearance and aroma, there was no significant difference (p>0.05 between the samples, and as for flavor and overall impression, the most accepted samples were those with sucrose and sucralose. The internal preference mapping indicated that the most accepted samples were those with sucrose, sucralose, and neotame were. The highest frequency of positive purchase intent scores was observed for sucrose and sucralose.

  20. Impact of Adolescent Sucrose Access on Cognitive Control, Recognition Memory, and Parvalbumin Immunoreactivity

    Science.gov (United States)

    Reichelt, Amy C.; Killcross, Simon; Hambly, Luke D.; Morris, Margaret J.; Westbrook, R. Fred

    2015-01-01

    In this study we sought to determine the effect of daily sucrose consumption in young rats on their subsequent performance in tasks that involve the prefrontal cortex and hippocampus. High levels of sugar consumption have been associated with the development of obesity, however less is known about how sugar consumption influences behavioral…

  1. Effect of sucrose concentration on the products of Kombucha fermentation on molasses.

    Science.gov (United States)

    Malbaša, R; Lončar, E; Djurić, M; Došenović, I

    2008-06-01

    Fermentation of 1.5g/l of Indian black tea, sweetened with adequate quantities of molasses (containing approx. 70g/l, 50g/l and 35g/l of sucrose), was conducted using domestic Kombucha. Inoculation was performed with 10% of fermentation broth from a previous process. The fermentation in cylindrical vessels containing 2l of liquid phase, was carried out at 22±1°C for 14 days, with periodical sampling, to measure pH, content of acids (total, acetic and l-lactic), content of remaining sucrose, and the yield of biomass at the end of fermentation. A product with 70g/l sucrose from molasses corresponds to an optimal concentration of carbon source, which provided metabolites with high pH, a low content of less desired acetic acid, a high content of highly desired l-lactic acid, an acceptable content of total acids and the highest possible level of utilisation of sucrose. Copyright © 2007 Elsevier Ltd. All rights reserved.

  2. Injectable Colloidal Gold in a Sucrose Acetate Isobutyrate Gelating Matrix with Potential Use in Radiation Therapy

    DEFF Research Database (Denmark)

    Jølck, Rasmus Irming; Binderup, Tina; Hansen, Anders Elias

    2014-01-01

    and sucrose acetate isobutyrate (SAIB) with improved properties compared to current solid fiducial markers. The developed nanogel is investigated in vitro and subsequently evaluated in vivo in immunocompetent NMRI mice. The nanogel shows high CT-contrast and excellent stability in vivo over a period of 12...

  3. Dextran synthesized by Leuconostoc mesenteroides BD1710 in tomato juice supplemented with sucrose.

    Science.gov (United States)

    Han, Jin; Hang, Feng; Guo, Benheng; Liu, Zhenmin; You, Chunpin; Wu, Zhengjun

    2014-11-04

    The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize approximately 32 g L(-1) dextran in the tomato-juice-sucrose medium when cultured at 28 °C for 48 h, which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the cultured tomato-juice-sucrose medium with various dextran contents was also measured. The results of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L. mesenteroides BD1710 in the tomato-juice-sucrose medium was dextran with a peak molecular weight of 6.35 × 10(5)Da, a linear backbone composed of consecutive α-(1 → 6)-linked d-glucopyranosyl units and approximately 6% α-(1 → 3) branches. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Comparative determination of sucrose content in sugar beet by polarimetric and isotope dilution methods

    Energy Technology Data Exchange (ETDEWEB)

    Malec, K; Szuchnik, A [Institute of Nuclear Research, Warsaw (Poland); Rydel, S; Walerianaczyk, E [Instytut Przemyslu Cukrowniczego, Warsaw (Poland)

    1976-01-01

    The comparative determination of sucrose content in sugar beets has been investigated by following methods: polarimetric, direct isotope dilution and double carrier-isotope dilution analysis. Basing upon the obtained results it has been ascertained, that in the case of worse quality beets the polarimetric determinations differ greatly from isotopic data.

  5. Composition of dental plaque formed in the presence of sucrose and after its interruption

    Directory of Open Access Journals (Sweden)

    Cury Jaime Aparecido

    2003-01-01

    Full Text Available Since dental plaque reservoirs of fluoride (F, calcium (Ca and inorganic phosphorus (Pi are susceptible to decreases in pH, this in situ crossover study was conducted to test the hypothesis that the low concentration of these ions in plaque, formed in the presence of sucrose, could be attributed merely to the fermentation of this sugar. Eleven volunteers wore palatal appliances containing 6 human enamel blocks during two stages. In each stage, the treatments were either 20% sucrose solution or distilled deionized water, which were dripped onto the blocks 8 times a day. After 28 days, in each stage, the dental plaque formed on two blocks was collected, the treatment was inverted and after a further 24 and 48 h, the biofilm formed was collected from the other blocks. The concentration of acid-soluble F, Ca and Pi, and the concentration of insoluble polysaccharide (IP were determined in the dental plaque. Statistically lower concentrations of F, Ca and Pi, and a higher concentration of IP were found in the 28-day biofilm formed in the presence of sucrose than in its absence; after the treatment inversion the change in F, Ca and Pi was not statistically significant, but the IP concentration changed significantly. The hypothesis was rejected because change in concentration of F, Ca and Pi is not due to fermentation of the sucrose.

  6. Sugar-Mediated Acclimation: The Importance of Sucrose Metabolism in Meristems

    NARCIS (Netherlands)

    Carpentier, S.C.; Vertommen, A.; Swennen, R.; Witters, E.; Fortes, C.; Souza, M.T.; Panis, B.

    2010-01-01

    We have designed an in vitro experimental setup to study the role of sucrose in sugar-mediated acclimation of banana meristems using established highly proliferating meristem cultures. It is a first step toward the systems biology of a meristem and the understanding of how it can survive severe

  7. Short-term effects of glucose and sucrose on cognitive performance and mood in elderly people

    NARCIS (Netherlands)

    Zwaluw, N.L. van der; Rest, O. van de; Kessels, R.P.C.; Groot, C.P.G.M. de

    2014-01-01

    In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with

  8. Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

    Directory of Open Access Journals (Sweden)

    Adewale Adewuyi

    2016-12-01

    Full Text Available Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.

  9. Directed shift of vaginal microbiota induced by vaginal application of sucrose gel in rhesus macaques.

    Science.gov (United States)

    Hu, Kai-tao; Zheng, Jin-xin; Yu, Zhi-jian; Chen, Zhong; Cheng, Hang; Pan, Wei-guang; Yang, Wei-zhi; Wang, Hong-yan; Deng, Qi-wen; Zeng, Zhong-ming

    2015-04-01

    Sucrose gel was used to treat bacterial vaginosis in a phase III clinical trial. However, the changes of vaginal flora after treatment were only examined by Nugent score in that clinical trial, While the vaginal microbiota of rhesus macaques is characterized by anaerobic, Gram-negative bacteria, few lactobacilli, and pH levels above 4.6, similar to the microbiota of patients with bacterial vaginosis. This study is aimed to investigate the change of the vaginal microbiota of rehsus macaques after topical use of sucrose gel to reveal more precisely the bacterial population shift after the topical application of sucrose gel. Sixteen rhesus macaques were treated with 0.5 g sucrose gel vaginally and three with 0.5 g of placebo gel. Vaginal swabs were collected daily following treatment. Vaginal pH levels and Nugent scores were recorded. The composition of the vaginal micotbiota was tested by V3∼V4 16S rDNA metagenomic sequencing. Dynamic changes in the Lactobacillus genus were analyzed by qPCR. The vaginal microbiota of rhesus macaques are dominated by anaerobic Gram-negative bacteria, with few lactobacilli and high pH levels above 4.6. After five days' treatment with topical sucrose gel, the component percentage of Lactobacillus in vaginal microbiota increased from 1.31% to 81.59%, while the component percentage of Porphyromonas decreased from 18.60% to 0.43%, Sneathia decreased from 15.09% to 0.89%, Mobiluncus decreased from 8.23% to 0.12%, etc.. The average vaginal pH values of 16 rhesus macaques of the sucrose gel group decreased from 5.4 to 3.89. There were no significant changes in microbiota and vaginal pH observed in the placebo group. Rhesus macaques can be used as animal models of bacterial vaginosis to develop drugs and test treatment efficacy. Furthermore, the topical application of sucrose gel induced the shifting of vaginal flora of rhesus macaques from a BV kind of flora to a lactobacilli-dominating flora. Copyright © 2015 The Authors. Published by

  10. Effect of sucrose concentration and gamma irradiation on growth and essential oil composition of spearmint plant through tissue culture

    International Nuclear Information System (INIS)

    El-Sharnouby, M.E.

    2007-01-01

    In vitro culture of spearmint plant (Mentha spicata L) using different sucrose concentrations and different gamma irradiation treatments was investigated. The shoot tips of spearmint plant were cultured on MS medium without hormones and supplemented with different concentrations of sucrose (10, 20, 30 and 40 g/l) then exposed to different gamma irradiation treatments (2,4,6 and 8 Krad) to determine their effects on growth and chemical composition in different sub-culturing media . The data showed that culturing shoots of Mentha spicata on MS medium containing 10 g/l sucrose produced the highest values of callus than other treatments and the maximum number of shoots was produced on MS medium supplemented with 20 g/l sucrose. Irradiation of spearmint shoots at 8 Krad when cultured on MS medium containing 30 or 40 g/l sucrose caused minimum number of shoots, whereas the longest shoots were produced with MS medium containing 20 g/l sucrose after irradiation at 60 Gy gamma dose. Treating shoots of Mentha spicata by gamma irradiation at 8 Krad and culturing on MS medium containing 30 g/l sucrose produced all sub-cultures in shortest length of shoots. Moreover, adding 40 g/l of sucrose in MS medium gave the highest number of leaves than other treatments. Exposing shoots of spearmint plant to gamma irradiation at 8 Krad decreased the number of leaves when culturing on MS medium containing 10 or 30 g/l sucrose. Furthermore, the selected samples showed many differences on spearmint oil composition and proline content regarding sucrose levels and gamma irradiation doses

  11. Effects of elevated carbon dioxide and sucrose concentrations on Arabidopsis thaliana root architecture and anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Lee-Ho, E.; Walton, L.J.; Reid, D.M.; Yeung, E.C.; Kurepin, L.V. [Calgary Univ., AB (Canada). Dept. of Biology

    2007-03-15

    Plant root growth is known to be influenced by higher levels of atmospheric carbon dioxide (CO{sub 2}). Roots of some species grown in hydroponics under elevated CO{sub 2} concentrations may be more competitive sinks for photosynthetic assimilates than roots grown under lower CO{sub 2} conditions. Root branching patterns may also be influenced by elevated CO{sub 2} concentrations. Studies have also shown that factors such as soil compaction, salinity and the availability of nitrate, phosphorous, oxygen and water also influence root growth, and the effects of higher CO{sub 2} on roots can be confounded by such environmental factors. This study evaluated the effects of elevated carbon dioxide and sucrose concentrations on Arabidopsis thaliana root growth, morphology, and architecture. Both ambient and elevated CO{sub 2} levels were used along with various sucrose concentrations. The study revealed that A. thaliana plants grown on a phytagar medium in small chambers with elevated CO{sub 2} had longer roots, more lateral root growth than plants grown in ambient CO{sub 2}. Roots in elevated CO{sub 2} were found to have wider root diameters, and more secondary growth. The addition of sucrose to the media closely resembled the effects of elevated CO{sub 2}. In addition, the increase in sucrose concentration had a bigger effect on root morphology under ambient, than elevated CO{sub 2}. Therefore, both elevated CO{sub 2} and increased sucrose concentrations promote root growth by increasing their number, length, and diameter. The dichotomy branching index (DBI) also dropped resulting in a more dichotomous branching pattern. 34 refs., 5 figs.

  12. Rheological and sensory performance of a protein-based sweetener (MNEI), sucrose, and aspartame in yogurt.

    Science.gov (United States)

    Miele, Nicoletta A; Cabisidan, Erliza K; Blaiotta, Giuseppe; Leone, Serena; Masi, Paolo; Di Monaco, Rossella; Cavella, Silvana

    2017-12-01

    Sweeteners and flavors are generally added to yogurt to make them more palatable. However, the addition of these ingredients may affect the fermentation process of yogurt as well as its physical and sensory characteristics. Consumers prioritize yogurt products that are "natural." A modified single-chain form of the natural sweet protein monellin extracted from the fruit of Dioscoreophyllum cumminsii, called MNEI, could be a useful alternative to artificial sweeteners. The aim of the present work was to evaluate new rapid sensory methods in combination with rheology to assess the viability of using MNEI to develop sweetened yogurts without the calories of sugar. We studied the gelation and cooling kinetics of 4 yogurt samples (unsweetened or sweetened with MNEI, aspartame, or sucrose) by using a rheometer. Furthermore, the 4 yogurts, with and without addition of a flavoring agent, were characterized from a sensory perspective using a combination of 2 rapid sensory methods, ultra flash profile and flash profile. Rheological results showed that, when added at typical usage levels, aspartame, sucrose, and MNEI did not generally affect the yogurt fermentation process or its rheological properties. Sensory results demonstrated that texture attributes of yogurts with aspartame and sucrose were strongly linked to sweetness and flavor perception, but this was not true for MNEI-sweetened yogurts. In contrast to results obtained from samples sweetened with sucrose and aspartame, MNEI protein did not sweeten the yogurt when added before fermentation. This study highlights the enhancing effect of flavor on sweetness perception, supporting previous reports that noted synergistic effects between sucrose or aspartame and flavors. Hence, future studies should be conducted to determine how sweet proteins behave in yogurt when added after fermentation. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Effects of sucrose concentration and water deprivation on Pavlovian conditioning and responding for conditioned reinforcement.

    Science.gov (United States)

    Tabbara, Rayane I; Maddux, Jean-Marie N; Beharry, Priscilla F; Iannuzzi, Jessica; Chaudhri, Nadia

    2016-04-01

    An appetitive Pavlovian conditioned stimulus (CS) can predict an unconditioned stimulus (US) and acquire incentive salience. We tested the hypothesis that US intensity and motivational state of the subject would influence Pavlovian learning and impact the attribution of incentive salience to an appetitive Pavlovian CS. To this end, we examined the effects of sucrose concentration and water deprivation on the acquisition of Pavlovian conditioning and responding for a conditioned reinforcer. Male Long-Evans rats (Harlan; 220-240 g) receiving 3% (3S) or 20% (20S) sucrose were either non-water deprived or given water for 1 hr per day. During Pavlovian conditioning sessions, half the rats in each concentration and deprivation condition received a 10-s CS paired with 0.2 ml of sucrose (16 trials/session; 3.2 ml/session). The remainder received unpaired CS and US presentations. Entries into a port where sucrose was delivered were recorded. Next, responding for conditioned reinforcement was tested, wherein pressing an active lever produced the CS and pressing an inactive lever had no consequences. CS-elicited port entries increased, and latency to the first CS-elicited port entry decreased across sessions in paired groups. Water deprivation augmented these effects, whereas sucrose concentration had no significant impact on behavior. Responding for conditioned reinforcement was observed in the 20S water-deprived, paired group. Thus, water deprivation can facilitate the acquisition of Pavlovian conditioning, potentially by enhancing motivational state, and a high-intensity US and a high motivational state can interact to heighten the attribution of incentive salience to an appetitive Pavlovian CS. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Intragastric Gelation of Heated Soy Protein Isolate-Alginate Mixtures and Its Effect on Sucrose Release.

    Science.gov (United States)

    Huang, Zhaozhi; Gruen, Ingolf; Vardhanabhuti, Bongkosh

    2018-06-15

    The goal of our study was to investigate the effect of alginate on in vitro gastric digestion and sucrose release of soy protein isolate (SPI) in model beverages. Model beverages containing 5% w/w SPI, 0% to 0.20% w/w alginate, and 10% w/w sucrose were prepared by heating the mixtures at 85 °C for 30 min at pH 6.0 or 7.0. Characterizations of beverages included determination of zeta potential, particle size and rheological properties. Digestion patterns and sucrose release profiles were determined during 2 hr in vitro gastric digestion using SDS-PAGE and HPLC analysis, respectively. Increasing alginate concentration led to increased negative surface charge, particle size, as well as viscosity and pseudoplastic behavior; however, no phase separation was observed. SPI beverages formed intragastric gel during in vitro gastric digestion when the formulations contained alginate or at pH 6.0 without alginate. Formation of the intragastric gel led to delayed protein digestion and release of sucrose. Higher resistance to digestion and a slower sucrose release rate were exhibited at increased alginate concentration, and to a lesser extent, at pH 6.0. This suggests that electrostatic interaction between SPI and alginate that occurred when the beverages were under gastric condition could be responsible for the intragastric gelation. These results could potentially lead to the formulation of SPI beverages with functionality to lower postprandial glycemic response. The results could be used to design beverages or semi solid food products with altered digestion properties and lowered or slower glucose release. © 2018 Institute of Food Technologists®.

  15. Structural insights into the cubic-hexagonal phase transition kinetics of monoolein modulated by sucrose solutions.

    Science.gov (United States)

    Reese, Caleb W; Strango, Zachariah I; Dell, Zachary R; Tristram-Nagle, Stephanie; Harper, Paul E

    2015-04-14

    Using DSC (differential scanning calorimetry), we measure the kinetics of the cubic-HII phase transition of monoolein in bulk sucrose solutions. We find that the transition temperature is dramatically lowered, with each 1 mol kg(-1) of sucrose concentration dropping the transition by 20 °C. The kinetics of this transition also slow greatly with increasing sucrose concentration. For low sucrose concentrations, the kinetics are asymmetric, with the cooling (HII-cubic) transition taking twice as long as the heating (cubic-HII) transition. This asymmetry in transition times is reduced for higher sucrose concentrations. The cooling transition exhibits Avrami exponents in the range of 2 to 2.5 and the heating transition shows Avrami exponents ranging from 1 to 3. A classical Avrami interpretation would be that these processes occur via a one or two dimensional pathway with variable nucleation rates. A non-classical perspective would suggest that these exponents reflect the time dependence of pore formation (cooling) and destruction (heating). New density measurements of monoolein show that the currently accepted value is about 5% too low; this has substantial implications for electron density modeling. Structural calculations indicate that the head group area and lipid length in the cubic-HII transition shrink by about 12% and 4% respectively; this reduction is practically the same as that seen in a lipid with a very different molecular structure (rac-di-12:0 β-GlcDAG) that makes the same transition. Thermodynamic considerations suggest there is a hydration shell about one water molecule thick in front of the lipid head groups in both the cubic and HII phases.

  16. Acute effects of feeding fructose, glucose and sucrose on blood lipid levels and systemic inflammation.

    Science.gov (United States)

    Jameel, Faizan; Phang, Melinda; Wood, Lisa G; Garg, Manohar L

    2014-12-16

    Recent studies have demonstrated a relationship between fructose consumption and risk of developing metabolic syndrome. Mechanisms by which dietary fructose mediates metabolic changes are poorly understood. This study compared the effects of fructose, glucose and sucrose consumption on post-postprandial lipemia and low grade inflammation measured as hs-CRP. This was a randomized, single blinded, cross-over trial involving healthy subjects (n=14). After an overnight fast, participants were given one of 3 different isocaloric drinks, containing 50 g of either fructose or glucose or sucrose dissolved in water. Blood samples were collected at baseline, 30, 60 and 120 minutes post intervention for the analysis of blood lipids, glucose, insulin and high sensitivity C-reactive protein (hs-CRP). Glucose and sucrose supplementation initially resulted in a significant increase in glucose and insulin levels compared to fructose supplementation and returned to near baseline values within 2 hours. Change in plasma cholesterol, LDL and HDL-cholesterol (measured as area under curve, AUC) was significantly higher when participants consumed fructose compared with glucose or sucrose (PAUC for plasma triglyceride levels however remained unchanged regardless of the dietary intervention. Change in AUC for hs-CRP was also significantly higher in subjects consuming fructose compared with those consuming glucose (P<0.05), but not sucrose (P=0.07). This study demonstrates that fructose as a sole source of energy modulates plasma lipids and hsCRP levels in healthy individuals. The significance of increase in HDL-cholesterol with a concurrent increase in LDL-cholesterol and elevated hs-CRP levels remains to be delineated when considering health effects of feeding fructose-rich diets. ACTRN12614000431628.

  17. Production of 5-ketofructose from fructose or sucrose using genetically modified Gluconobacter oxydans strains.

    Science.gov (United States)

    Siemen, Anna; Kosciow, Konrad; Schweiger, Paul; Deppenmeier, Uwe

    2018-02-01

    The growing consumer demand for low-calorie, sugar-free foodstuff motivated us to search for alternative non-nutritive sweeteners. A promising sweet-tasting compound is 5-keto-D-fructose (5-KF), which is formed by membrane-bound fructose dehydrogenases (Fdh) in some Gluconobacter strains. The plasmid-based expression of the fdh genes in Gluconobacter (G.) oxydans resulted in a much higher Fdh activity in comparison to the native host G. japonicus. Growth experiments with G. oxydans fdh in fructose-containing media indicated that 5-KF was rapidly formed with a conversion efficiency of 90%. 5-KF production from fructose was also observed using resting cells with a yield of about 100%. In addition, a new approach was tested for the production of the sweetener 5-KF by using sucrose as a substrate. To this end, a two-strain system composed of the fdh-expressing strain and a G. oxydans strain that produced the sucrose hydrolyzing SacC was developed. The strains were co-cultured in sucrose medium and converted 92.5% of the available fructose units into 5-KF. The glucose moiety of sucrose was converted to 2-ketogluconate and acetate. With regard to the development of a sustainable and resource-saving process for the production of 5-KF, sugar beet extract was used as substrate for the two-strain system. Fructose as product from sucrose cleavage was mainly oxidized to 5-KF which was detected in a concentration of over 200 mM at the end of the fermentation process. In summary, the two-strain system was able to convert fructose units of sugar beet extract to 5-KF with an efficiency of 82 ± 5%.

  18. Epizootic vacuolar myelinopathy of the central nervous system of bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana)

    Science.gov (United States)

    Thomas, N.J.; Meteyer, C.U.; Sileo, L.

    1998-01-01

    toxicity from hexachlorophene, triethyltin, bromethalin, isonicotinic acid hydrazide, and certain exotic plant toxins; however, despite exhaustive testing, no etiology was determined for the DeGray Lake mortality events. This is the first report of vacuolar myelinopathy associated with spontaneous mortality in wild birds.

  19. Evolution of vacuolar proton pyrophosphatase domains and volutin granules: clues into the early evolutionary origin of the acidocalcisome

    Directory of Open Access Journals (Sweden)

    Valerio Alejandro

    2011-10-01

    Full Text Available Abstract Background Volutin granules appear to be universally distributed and are morphologically and chemically identical to acidocalcisomes, which are electron-dense granular organelles rich in calcium and phosphate, whose functions include storage of phosphorus and various metal ions, metabolism of polyphosphate, maintenance of intracellular pH, osmoregulation and calcium homeostasis. Prokaryotes are thought to differ from eukaryotes in that they lack membrane-bounded organelles. However, it has been demonstrated that as in acidocalcisomes, the calcium and polyphosphate-rich intracellular "volutin granules (polyphosphate bodies" in two bacterial species, Agrobacterium tumefaciens, and Rhodospirillum rubrum, are membrane bound and that the vacuolar proton-translocating pyrophosphatases (V-H+PPases are present in their surrounding membranes. Volutin granules and acidocalcisomes have been found in organisms as diverse as bacteria and humans. Results Here, we show volutin granules also occur in Archaea and are, therefore, present in the three superkingdoms of life (Archaea, Bacteria and Eukarya. Molecular analyses of V-H+PPase pumps, which acidify the acidocalcisome lumen and are diagnostic proteins of the organelle, also reveal the presence of this enzyme in all three superkingdoms suggesting it is ancient and universal. Since V-H+PPase sequences contained limited phylogenetic signal to fully resolve the ancestral nodes of the tree, we investigated the divergence of protein domains in the V-H+PPase molecules. Using Protein family (Pfam database, we found a domain in the protein, PF03030. The domain is shared by 31 species in Eukarya, 231 in Bacteria, and 17 in Archaea. The universal distribution of the V-H+PPase PF03030 domain, which is associated with the V-H+PPase function, suggests the domain and the enzyme were already present in the Last Universal Common Ancestor (LUCA. Conclusion The importance of the V-H+PPase function and the

  20. Activity of the C-terminal-dependent vacuolar sorting signal of horseradish peroxidase C1a is enhanced by its secondary structure.

    Science.gov (United States)

    Matsui, Takeshi; Tabayashi, Ayako; Iwano, Megumi; Shinmyo, Atsuhiko; Kato, Ko; Nakayama, Hideki

    2011-02-01

    Plant class III peroxidase (PRX) catalyzes the oxidation and oxidative polymerization of a variety of phenolic compounds while reducing hydrogen peroxide. PRX proteins are classified into apoplast type and vacuole type based on the absence or the presence of C-terminal propeptides, which probably function as vacuolar sorting signals (VSSs). In this study, in order to improve our understanding of vacuole-type PRX, we analyzed regulatory mechanisms of vacuolar sorting of a model vacuole-type PRX, the C1a isozyme of horseradish (Armoracia rusticana) (HRP C1a). Using cultured transgenic tobacco cells and protoplasts derived from horseradish leaves, we characterized HRP C1a's VSS, which is a 15 amino acid C-terminal propeptide (C15). We found that the C-terminal hexapeptide of C15 (C6), which is well conserved among vacuole-type PRX proteins, forms the core of the C-terminal-dependent VSS. We also found that the function of C6 is enhanced by the remaining N-terminal part of C15 which probably folds into an amphiphilic α-helix.

  1. Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm – caries model

    Directory of Open Access Journals (Sweden)

    Juliana Nunes BOTELHO

    2016-01-01

    Full Text Available Abstract Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day to one of the following treatments: 0.9% NaCl (negative control, 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose. To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day the culture medium pH. After 4 (dentine or 5 (enamel days of growth, biofilms (n = 9 were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001 on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

  2. Interaction of dietary sucrose and fiber on serum lipids in healthy young men fed high carbohydrate diets.

    Science.gov (United States)

    Albrink, M J; Ullrich, I H

    1986-03-01

    High sucrose diets may cause increased serum triglycerides and decreased high density lipoprotein concentration. To determine whether dietary fiber protects against these effects, four groups of six healthy young men were assigned to one of four very high carbohydrate diets providing 0, 18, 36, or 52% of calories as sucrose. Each diet was fed in both low (less than 14 g) and high (greater than 34 g) levels of dietary fiber for 10 days each. Triglycerides increased during the 36 and 52% sucrose diets compared to 0 and 18% sucrose diets, and fiber protected partially against this rise. Serum cholesterol and LDL cholesterol were lower during the 0 and 18% sucrose diets than the 36 or 52% sucrose diets but fiber had no effect. HDL cholesterol decreased during all low fat diets, with a trend toward a greater decrease during the high sucrose diets. The results suggest that fiber protects against carbohydrate-induced lipemia but has no effect on cholesterol during very high carbohydrate diets.

  3. Up-regulation of sucrose metabolizing enzymes in Oncidium goldiana grown under elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Chang Run Li; Sun, W.Q.; Choy Sin Hew [National Univ. of Singapore. dept. of Biological Sciences (Singapore)

    2001-07-01

    Experiments were conducted in controlled growth chambers to evaluate how increase in CO{sub 2} concentration affected sucrose metabolizing enzymes, especially sucrose phosphate synthase (SPS; EC 2.4.1.14) and sucrose synthase (SS; EC 2.4.1.13), as well as carbon metabolism and partitioning in a tropical epiphytic orchid species (Oncidium goldiana). Response of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) to elevated CO{sub 2} was determined along with dry mass production, photosynthesis rate, chlorophyll content, total nitrogen and total soluble protein content. After 60 days of growth, there was a 80% and 150% increase in dry mass production in plants grown at 750 and 1100 {mu} l{sup -}1 CO{sub 2}, respectively, compared with those grown at ambient CO{sub 2} (about 370 {mu} l{sup -}1). A similar increase in photosynthesis rate was detected throughout the growth period when measured under growth CO{sub 2} conditions. Concomitantly, there was a decline in leaf Rubisco activity in plants in elevated CO{sub 2} after 10 days of growth. Over the growth period, leaf SPS and SS activities were up-regulated by an average of 20% and 40% for plants grown at 750 and 1100 {mu} l{sup -}1 CO{sub 2}, respectively. Leaf sucrose content and starch content were significantly higher throughout the growth period in plants grown at elevated CO{sub 2} than those at ambient CO{sub 2}. The partitioning of photosynthetically fixed carbon between sucrose and starch appeared to be unaffected by the 750 {mu} l{sup -}1 CO{sub 2} treatment, but it was favored into starch under the 1100 {mu} l{sup -}1 CO{sub 2} condition. The activities of SPS and SS in leaf extracts were closely associated with photosynthetic rates and with partitioning of carbon between starch and sucrose in leaves. The data are consistent with the hypothesis that the up-regulation of leaf SPS and SS might be an acclimation response to optimize the utilization and export of organic carbon with the

  4. Enhanced salt stress tolerance of rice plants expressing a vacuolar H+-ATPase subunit c1 (SaVHAc1) gene from the halophyte grass Spartina alterniflora Löisel

    Science.gov (United States)

    The physiological role of a vacuolar ATPase subunit c1 (SaVHAc1) from a halophyte grass Spartina alterniflora was studied through its expression in rice. The SaVHAc1– expressing plants showed enhanced tolerance to salt stress than the wild-type plants, mainly through adjustments in early stage and p...

  5. HYPERPHAGIA INDUCED BY SUCROSE: RELATION TO CIRCULATING AND CSF GLUCOSE AND CORTICOSTERONE AND OREXIGENIC PEPTIDES IN THE ARCUATE NUCLEUS

    Science.gov (United States)

    Gaysinskaya, V. A.; Karatayev, O.; Shuluk, J.; Leibowitz, S. F.

    2010-01-01

    Sucrose-rich diets compared to starch-rich diets are known to stimulate overeating under chronic conditions. The present study in normal-weight rats established an acute “preload-to-test meal” paradigm for demonstrating sucrose-induced hyperphagia and investigating possible mechanisms that mediate this behavioral phenomenon. In this acute paradigm, the rats were first given a small (15 kcals) sucrose preload (30% sucrose) for 30 min compared to an equicaloric, starch preload (25% starch with 5% sucrose) and then allowed to freely consume a subsequent test meal of lab chow. The sucrose preload, when compared to a starch preload equal in energy density and palatability, consistently increased food intake in the subsequent test meal occurring between 60–120 min after the end of the preload. Measurements of hormones, metabolites and hypothalamic peptides immediately preceding this hyperphagia revealed marked differences between the sucrose vs starch groups that could contribute to the increase in food intake. Whereas the sucrose group compared to starch group immediately after the preload (at 10 min) had elevated levels of glucose in serum and cerebrospinal fluid (CSF) along with reduced expression of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus (ARC), the subsequent effects (at 30–60 min) just preceding the test meal hyperphagia were the reverse. Along with lower levels of glucose, they included markedly elevated serum and CSF levels of corticosterone and mRNA levels of NPY and AgRP in the ARC. In addition to establishing an animal model for sucrose-induced hyperphagia, these results demonstrate peripheral and central mechanisms that may mediate this behavioral phenomenon. PMID:21036188

  6. The effect of early-life stress and chronic high-sucrose diet on metabolic outcomes in female rats.

    Science.gov (United States)

    Maniam, Jayanthi; Antoniadis, Christopher P; Morris, Margaret J

    2015-01-01

    Early-life stress affects metabolic outcomes and choice of diet influences the development of metabolic disease. Here we tested the hypothesis that chronic sugar intake exacerbates metabolic deficits induced by early-life stress. Early-life stress was induced in Sprague-Dawley rats using limited nesting material in early lactation (LN, postnatal days 2-9), and siblings were given chow alone or with additional sucrose post weaning (n = 9-17 per group). Female control and LN siblings had unlimited access to either chow plus water, or chow and water plus 25% sucrose solution (Sucrose), from 3-15 weeks of age. Weekly body weight and food intake were measured. Glucose and insulin tolerance were tested at 13 and 14 weeks of age, respectively. Rats were killed at 15 weeks. Hepatic triglyceride and markers of lipid synthesis - fatty acid synthase, acetyl-CoA carboxylase alpha and oxidation - and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α) were examined. Mediators of hepatic glucocorticoid metabolism, specifically 11-beta hydroxysteroid dehydrogenase-1 (11βHSD-1), 5-α reductase, and glucocorticoid and mineralocorticoid receptor mRNAs were also measured. Sucrose increased caloric intake in both groups, but overall energy intake was not altered by LN exposure. LN exposure had no further impact on sucrose-induced glucose intolerance and increased plasma and liver triglycerides. Hepatic markers of fat synthesis and oxidation were concomitantly activated and 11βHSD-1 mRNA expression was increased by 53% in LN-Sucrose versus Con-Sucrose rats. Adiposity was increased by 26% in LN-Sucrose versus Con-Sucrose rats. Thus, LN exposure had minimal adverse metabolic effects despite high-sugar diet postweaning.

  7. Lactose and sucrose aqueous solutions for high-dose dosimetry with 10-MeV electron beam irradiation

    International Nuclear Information System (INIS)

    Amraei, R.; Kheirkhah, M.; Raisali, G.

    2012-01-01

    In the present study, dosimetric characterisation of aqueous solutions of lactose and sucrose was analysed by UV spectrometry following irradiation using 10-MeV electron beam at doses between 0.5 and 10.5 kGy. As a dosimetric index, absorbance is selected at 256 and 264 nm for lactose and sucrose aqueous solutions, respectively. The intensity of absorbance for irradiated solutions depends on the pre-irradiation concentration of lactose and sucrose. The post-irradiation stability of both solutions was investigated at room temperature for a measurement period of 22 d. (authors)

  8. Sucrose mimics the light induction of Arabidopsis nitrate reductase gene transcription

    DEFF Research Database (Denmark)

    Cheng, Chi-Lien; Acedo, Gregoria N; Kristensen, Michael

    1992-01-01

    can replace light in eliciting an increase of nitrate reductase mRNA accumulation in dark-adapted green Arabidopsis plants. We show further that sucrose alone is sufficient for the full expression of nitrate reductase genes in etiolated Arabidopsis plants. Finally, using a reporter gene, we show......Nitrate reductase, the first enzyme in nitrate assimilation, is located at the crossroad of two energy-consuming pathways: nitrate assimilation and carbon fixation. Light, which regulates the expression of many higher-plant carbon fixation genes, also regulates nitrate reductase gene expression....... Located in the cytosol, nitrate reductase obtains its reductant not from photosynthesis but from carbohydrate catabolism. This relationship prompted us to investigate the indirect role that light might play, via photosynthesis, in the regulation of nitrate reductase gene expression. We show that sucrose...

  9. Preparation of synaptic plasma membrane and postsynaptic density proteins using a discontinuous sucrose gradient.

    Science.gov (United States)

    Bermejo, Marie Kristel; Milenkovic, Marija; Salahpour, Ali; Ramsey, Amy J

    2014-09-03

    Neuronal subcellular fractionation techniques allow the quantification of proteins that are trafficked to and from the synapse. As originally described in the late 1960's, proteins associated with the synaptic plasma membrane can be isolated by ultracentrifugation on a sucrose density gradient. Once synaptic membranes are isolated, the macromolecular complex known as the post-synaptic density can be subsequently isolated due to its detergent insolubility. The techniques used to isolate synaptic plasma membranes and post-synaptic density proteins remain essentially the same after 40 years, and are widely used in current neuroscience research. This article details the fractionation of proteins associated with the synaptic plasma membrane and post-synaptic density using a discontinuous sucrose gradient. Resulting protein preparations are suitable for western blotting or 2D DIGE analysis.

  10. Diet-dependent gene expression in honey bees: honey vs. sucrose or high fructose corn syrup.

    Science.gov (United States)

    Wheeler, Marsha M; Robinson, Gene E

    2014-07-17

    Severe declines in honey bee populations have made it imperative to understand key factors impacting honey bee health. Of major concern is nutrition, as malnutrition in honey bees is associated with immune system impairment and increased pesticide susceptibility. Beekeepers often feed high fructose corn syrup (HFCS) or sucrose after harvesting honey or during periods of nectar dearth. We report that, relative to honey, chronic feeding of either of these two alternative carbohydrate sources elicited hundreds of differences in gene expression in the fat body, a peripheral nutrient-sensing tissue analogous to vertebrate liver and adipose tissues. These expression differences included genes involved in protein metabolism and oxidation-reduction, including some involved in tyrosine and phenylalanine metabolism. Differences between HFCS and sucrose diets were much more subtle and included a few genes involved in carbohydrate and lipid metabolism. Our results suggest that bees receive nutritional components from honey that are not provided by alternative food sources widely used in apiculture.

  11. Cloning and sequence analysis of sucrose phosphate synthase gene from varieties of Pennisetum species.

    Science.gov (United States)

    Li, H C; Lu, H B; Yang, F Y; Liu, S J; Bai, C J; Zhang, Y W

    2015-03-31

    Sucrose phosphate synthase (SPS) is an enzyme used by higher plants for sucrose synthesis. In this study, three primer sets were designed on the basis of known SPS sequences from maize (GenBank: NM_001112224.1) and sugarcane (GenBank: JN584485.1), and five novel SPS genes were identified by RT-PCR from the genomes of Pennisetum spp (the hybrid P. americanum x P. purpureum, P. purpureum Schum., P. purpureum Schum. cv. Red, P. purpureum Schum. cv. Taiwan, and P. purpureum Schum. cv. Mott). The cloned sequences showed 99.9% identity and 80-88% similarity to the SPS sequences of other plants. The SPS gene of hybrid Pennisetum had one nucleotide and four amino acid polymorphisms compared to the other four germplasms, and cluster analysis was performed to assess genetic diversity in this species. Additional characterization of the SPS gene product can potentially allow Pennisetum to be exploited as a biofuel source.

  12. Pilot scale anaerobic acidification of waste water containing sucrose and lactate

    Energy Technology Data Exchange (ETDEWEB)

    Zoetemeyer, R J; Borgerding, P H; Van den Heuvel, J C; Cohen, A; Boelhouwer, C

    1982-07-01

    The waste water from a sugar refinery, containing principally sucrose, lactate and ethanol as organic impurities, was anaerobically acidified at a pH of approximately 5.8 and an average temperature of 29 degrees C in a 1 meter cubed upflow reactor. The residence time was decreased, in steps, from 7.2 to 1.7 h. Sucrose was effectively metabolized in all cases, whereas lactate was only decomposed at longer residence times. Ethanol was not converted. The volume activity, and the sludge activity, could be increased to 250 kg/ cubic meters/d, and 14 kg/kg/d, respectively. Results indicated that in order to operate an acidification reactor at its maximum efficiency attention should be paid to the mixing system and to maintaining a constant pH. (Refs. 18).

  13. Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch

    Science.gov (United States)

    Gill, Balmeet Singh

    2014-01-01

    Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased