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Sample records for gibberellin ga3 enhances

  1. Regulation effects of exogenous gibberellin acid (GA 3 ) on the ...

    African Journals Online (AJOL)

    To fully understand the regulation effects of gibberellin on tomato (Solanum Lycoperscium) ovary locule formation and the fasciated transcription, two varieties: multi-locule 'MLK1' and few- locule 'FL1' which were highly different in locule number and fasciated transcriptional levels, were used in this study. By spraying GA3 ...

  2. GA(3) enhances root responsiveness to exogenous IAA by modulating auxin transport and signalling in Arabidopsis.

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    Li, Guijun; Zhu, Changhua; Gan, Lijun; Ng, Denny; Xia, Kai

    2015-03-01

    We used auxin-signalling mutants, auxin transport mutants, and auxin-related marker lines to show that exogenously applied GA enhances auxin-induced root inhibition by affecting auxin signalling and transport. Variation in root elongation is valuable when studying the interactions of phytohormones. Auxins influence the biosynthesis and signalling of gibberellins (GAs), but the influence of GAs on auxins in root elongation is poorly understood. This study was conducted to investigate the effect of GA3 on Arabidopsis root elongation in the presence of auxin. Root elongation was inhibited in roots treated with both IAA and GA3, compared to IAA alone, and the effect was dose dependent. Further experiments showed that GA3 could modulate auxin signalling based on root elongation in auxin-signalling mutants and the expression of auxin-responsive reporters. The GA3-enhanced inhibition of root elongation observed in the wild type was not found in the auxin-signalling mutants tir1-1 and axr1-3. GA3 increased DR5::GUS expression in the root meristem and elongation zones, and IAA2::GUS in the columella. The DR5rev::GFP signal was enhanced in columella cells of the root caps and in the elongation zone in GA3-treated seedling roots. A reduction was observed in the stele of PAC-treated roots. We also examined the effect of GA3 on auxin transport. The enhanced responsiveness caused by GA3 was not observed in the auxin influx mutant aux1-7 or the efflux mutant eir1-1. Additional molecular data demonstrated that GA3 could promote auxin transport via AUX1 and PIN proteins. However, GA3-induced PIN gene expression did not fully explain GA-enhanced PIN protein accumulation. These results suggest that GA3 is involved in auxin-mediated primary root elongation by modulating auxin signalling and transport, and thus enhances root responsiveness to exogenous IAA.

  3. Heterologous expression and transcript analysis of gibberellin biosynthetic genes of grasses reveals novel functionality in the GA3ox family.

    Science.gov (United States)

    Pearce, Stephen; Huttly, Alison K; Prosser, Ian M; Li, Yi-dan; Vaughan, Simon P; Gallova, Barbora; Patil, Archana; Coghill, Jane A; Dubcovsky, Jorge; Hedden, Peter; Phillips, Andrew L

    2015-06-05

    The gibberellin (GA) pathway plays a central role in the regulation of plant development, with the 2-oxoglutarate-dependent dioxygenases (2-ODDs: GA20ox, GA3ox, GA2ox) that catalyse the later steps in the biosynthetic pathway of particularly importance in regulating bioactive GA levels. Although GA has important impacts on crop yield and quality, our understanding of the regulation of GA biosynthesis during wheat and barley development remains limited. In this study we identified or assembled genes encoding the GA 2-ODDs of wheat, barley and Brachypodium distachyon and characterised the wheat genes by heterologous expression and transcript analysis. The wheat, barley and Brachypodium genomes each contain orthologous copies of the GA20ox, GA3ox and GA2ox genes identified in rice, with the exception of OsGA3ox1 and OsGA2ox5 which are absent in these species. Some additional paralogs of 2-ODD genes were identified: notably, a novel gene in the wheat B genome related to GA3ox2 was shown to encode a GA 1-oxidase, named as TaGA1ox-B1. This enzyme is likely to be responsible for the abundant 1β-hydroxylated GAs present in developing wheat grains. We also identified a related gene in barley, located in a syntenic position to TaGA1ox-B1, that encodes a GA 3,18-dihydroxylase which similarly accounts for the accumulation of unusual GAs in barley grains. Transcript analysis showed that some paralogs of the different classes of 2-ODD were expressed mainly in a single tissue or at specific developmental stages. In particular, TaGA20ox3, TaGA1ox1, TaGA3ox3 and TaGA2ox7 were predominantly expressed in developing grain. More detailed analysis of grain-specific gene expression showed that while the transcripts of biosynthetic genes were most abundant in the endosperm, genes encoding inactivation and signalling components were more highly expressed in the seed coat and pericarp. The comprehensive expression and functional characterisation of the multigene families encoding the 2-ODD

  4. Exogenous GA3 Application Enhances Xylem Development and Induces the Expression of Secondary Wall Biosynthesis Related Genes in Betula platyphylla

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    Huiyan Guo

    2015-09-01

    Full Text Available Gibberellin (GA is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla (birch seeds were treated with 300 ppm GA3 and/or 300 ppm paclobutrazol (PAC, seed germination was recorded, and transverse sections of hypocotyls were stained with toluidine blue; the two-month-old seedlings were treated with 50 μM GA3 and/or 50 μM PAC, transverse sections of seedling stems were stained using phloroglucinol–HCl, and secondary wall biosynthesis related genes expression was analyzed by real-time quantitative PCR. Results indicated that germination percentage, energy and time of seeds, hypocotyl height and seedling fresh weight were enhanced by GA3, and reduced by PAC; the xylem development was wider in GA3-treated plants than in the control; the expression of NAC and MYB transcription factors, CESA, PAL, and GA oxidase was up-regulated during GA3 treatment, suggesting their role in GA3-induced xylem development in the birch. Our results suggest that GA3 induces the expression of secondary wall biosynthesis related genes to trigger xylogenesis in the birch plants.

  5. Effect of the Application of Gibberellin (GA3 on Tomato Seed Germination (Solanum Lycopersicum L. Variety Santa Cruz

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    Yuli Alexandra Deaquiz-Oyola

    2013-12-01

    Full Text Available The tomato is one of the most important vegetable, economical and nutritionally, around the world. For this reason the germination process in the tomato is a vital stage in the growth and development of plants. In this study, the effect of different doses of gibberellin over the germination of Santa Cruz variety tomato seeds was evaluated. The seeds were embedded for 24 hours in different concentrations of gibberellic acid, sown in a peat substrate in the screen house of the UPTC. A complete randomized design was used with 4 treatments corresponding to 0, 100, 200 and 400 mg L-1 of GAs with three replicates, for a total of 12 experimental units (EU, and each unit with 35 seeds. The treatment of 0 mg L-1 had a favorable impact on the mean germination time (GT, average speed of germination (ASG and germination percentage (GP, showing significant differences with respect to the other treatments. The seeds soaked in 400 mg L-1 of GAs presented the lowest values in the variables GT, ASG and GP, attributed to negative effect this type of hormone over this tomato variety, which delayed the death of the embryo and the seed germination.

  6. ABA and GA3 increase carbon allocation in different organs of grapevine plants by inducing accumulation of non-structural carbohydrates in leaves, enhancement of phloem area and expression of sugar transporters.

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    Murcia, Germán; Pontin, Mariela; Reinoso, Herminda; Baraldi, Rita; Bertazza, Gianpaolo; Gómez-Talquenca, Sebastián; Bottini, Rubén; Piccoli, Patricia N

    2016-03-01

    Grape quality for winemaking depends on sugar accumulation and metabolism in berries. Abscisic acid (ABA) and gibberellins (GAs) have been reported to control sugar allocation in economically important crops, although the mechanisms involved are still unknown. The present study tested if ABA and gibberellin A3 (GA3) enhance carbon allocation in fruits of grapevines by modifying phloem loading, phloem area and expression of sugar transporters in leaves and berries. Pot-grown Vitis vinifera cv. Malbec plants were sprayed with ABA and GA3 solutions. The amount of soluble sugars in leaves and berries related to photosynthesis were examined at three points of berry growth: pre-veraison, full veraison and post-veraison. Starch levels and amylase activity in leaves, gene expression of sugar transporters in leaves and berries and phloem anatomy were examined at full veraison. Accumulation of glucose and fructose in berries was hastened in ABA-treated plants at the stage of full veraison, which was correlated with enhancement of Vitis vinifera HEXOSE TRANSPORTER 2 (VvHT2) and Vitis vinifera HEXOSE TRANSPORTER 6 (VvHT6) gene expression, increases of phloem area and sucrose content in leaves. On the other hand, GA3 increased the quantity of photoassimilates delivered to the stem thus increasing xylem growth. In conclusion, stimulation of sugar transport by ABA and GA3 to berries and stems, respectively, was due to build-up of non-structural carbohydrates in leaves, modifications in phloem tissue and modulation in gene expression of sugar transporters. © 2015 Scandinavian Plant Physiology Society.

  7. Gibberellin-enhanced elongation of inverted Pharbitis nil shoot prevents the release of apical dominance

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    Prasad, T. K.; Cline, M. G.

    1987-01-01

    Ethylene evolution resulting from the gravity stress of shoot inversion appears to induce the release of apical dominance in Pharbitis nil (L.) by inhibiting elongation of the inverted shoot. It has been previously demonstrated that this shoot inversion release of apical dominance can be prevented by promoting elongation in the inverted shoot via interference with ethylene synthesis or action. In the present study it was shown that apical dominance release can also be prevented by promoting elongation of the inverted shoot via treatment with gibberellic acid (GA3). A synergistic effect was observed when AgNO3, the ethylene action inhibitor, was applied with GA3. Both GA3 and AgNO3 increased ethylene production in the inverted shoot. These results are consistent with the view that it is ethylene-induced inhibition of elongation and not any direct effect of ethylene per se which is responsible for the outgrowth of the highest lateral bud.

  8. Opposing effects of external gibberellin and Daminozide on Stevia growth and metabolites.

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    Karimi, Mojtaba; Hashemi, Javad; Ahmadi, Ali; Abbasi, Alireza; Pompeiano, Antonio; Tavarini, Silvia; Guglielminetti, Lorenzo; Angelini, Luciana G

    2015-01-01

    Steviol glycosides (SVglys) and gibberellins are originated from the shared biosynthesis pathway in Stevia (Stevia rebaudiana Bertoni). In this research, two experiments were conducted to study the opposing effects of external gibberellin (GA3) and Daminozide (a gibberellin inhibitor) on Stevia growth and metabolites. Results showed that GA3 significantly increased the stem length and stem dry weight in Stevia. Total soluble sugar content increased while the SVglys biosynthesis was decreased by external GA3 applying in Stevia leaves. In another experiment, the stem length was reduced by Daminozide spraying on Stevia shoots. The Daminozide did not affect the total SVglys content, while in 30 ppm concentration, significantly increased the soluble sugar production in Stevia leaves. Although the gibberellins biosynthesis pathway has previously invigorated in Stevia leaf, the Stevia response to external gibberellins implying on high precision regulation of gibberellins biosynthesis in Stevia and announces that Stevia is able to kept endogenous gibberellins in a low quantity away from SVglys production. Moreover, the assumption that the internal gibberellins were destroyed by Daminozide, lack of Daminozide effects on SVglys production suggests that gibberellins biosynthesis could not act as a competitive factor for SVglys production in Stevia leaves.

  9. Exposure to red light, temperature and exogenous gibberellins ...

    African Journals Online (AJOL)

    Red light, temperature and gibberellins are well known for their capacity to induce higher germination in dormant seeds of several plant species. In the current study, we investigated the effect of various temperature (10, 13, 16, 19, 22 and 25°C) and gibberellic acid (GA3) and GA4+7 concentrations (0.1, 1, 10, and 100 uM) ...

  10. Green revolution trees: semidwarfism transgenes modify gibberellins, promote root growth, enhance morphological diversity, and reduce competitiveness in hybrid poplar.

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    Elias, Ani A; Busov, Victor B; Kosola, Kevin R; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W; Rood, Stewart B; Strauss, Steven H

    2012-10-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA(20) and GA(8), in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations.

  11. A mutant gene that increases gibberellin production in Brassica

    International Nuclear Information System (INIS)

    Rood, S.B.; Williams, P.H.; Pearce, D.; Pharis, R.P.; Murofushi, Noboru; Mander, L.N.

    1990-01-01

    A single gene mutant (elongated internode [ein/ein]) with accelerated shoot elongation was identified from a rapid cycling line of Brassica rapa. Relative to normal plants, mutant plants had slightly accelerated floral development, greater stem dry weights, and particularly, increased internode and inflorescence elongation. The application of the triazole plant growth retardant, paclobutrazol, inhibited shoot elongation, returning ein to a more normal phenotype. Conversely, exogenous gibberellin A 3 (GA 3 ) can convert normal genotypes to a phenotype resembling ein. The content of endogenous GA 1 and GA 3 were estimated by gas chromatography-selected ion monitoring using [ 2 H]GA 1 as a quantitative internal standard and at day 14 were 1.5- and 12.1-fold higher per stem, respectively, in ein than in normal plants, although GA concentrations were more similar. The endogenous levels of GA 20 and GA 1 , and the rate of GA 19 metabolism were simultaneously analyzed. Levels of GA 1 and GA 20 were 4.6- and 12.9-fold higher, respectively, and conversions to GA 20 and GA 1 were 8.3 and 1.3 times faster in ein than normal plants. Confirming the enhanced rate of GA 1 biosynthesis in ein, the conversion of [ 3 H]GA 20 to [ 3 H] GA 1 was also faster in ein than in the normal genotype. Thus, the ein allele results in accelerated GA 1 biosynthesis and an elevated content of endogenous GAs, including the dihydroxylated GAs A 1 and A 3

  12. Analysis of Transcriptional Responses of the Inflorescence Meristems in Jatropha curcas Following Gibberellin Treatment

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    Wen-Kai Hui

    2018-02-01

    Full Text Available Jatropha curcas L. seeds an oilseed plant with great potential for biodiesel production. However, low seed yield, which was limited by its lower female flowers, was a major drawback for its utilization. Our previous study found that the flower number and female-to-male ratio were increased by gibberellin treatment. Here, we compared the transcriptomic profiles of inflorescence meristem at different time points after gibberellic acid A3 (GA3 treatment. The present study showed that 951 differentially expressed genes were obtained in response to gibberellin treatment, compared with control samples. The 6-h time point was an important phase in the response to exogenous gibberellin. Furthermore, the plant endogenous gibberellin, auxin, ethylene, abscisic acid, and brassinolide-signaling transduction pathways were repressed, whereas the genes associated with cytokinin and jasmonic acid signaling were upregulated for 24-h time point following GA3 treatment. In addition, the floral meristem determinacy genes (JcLFY, JcSOC1 and floral organ identity genes (JcAP3, JcPI, JcSEP1-3 were significantly upregulated, but their negative regulator (JcSVP was downregulated after GA3 treatment. Moreover, the effects of phytohormone, which was induced by exogenous plant growth regulator, mainly acted on the female floral differentiation process. To the best of our knowledge, this data is the first comprehensive analysis of the underlying transcriptional response mechanism of floral differentiation following GA3 treatment in J. curcas, which helps in engineering high-yielding varieties of Jatropha.

  13. Evidence for the Translocation of Gibberellin A_3 and Gibberellin-Like Substances in Grafts between Normal, Dwarf_1 and Dwarf_5 Seedlings of Zea mays L.

    OpenAIRE

    M., Katsumi; D.E., Foard; B.O., Phinney; Biology Department, International Christian University; Department of Botany and Plant Pathology, Purdue University; Department of Biology, University of California

    1983-01-01

    Approach grafts were made between the cut surfaces of mesocotyls from normal and dwarf seedlings of Zea mays L. (maize). The dwarfs were the non-allelic single gene gibberellin mutants, dwarf_1 and dwarf_5. The graft combinations were normal-normal, normal-dwarf_1, normal-dwarf_5, dwarf_1-dwarf_1, dwarf_5-dwarf_5, and dwarf_1-dwarf_5. The grafts were used to demonstrate the movement of gibberellin-like substances across the union. GA_3, added to one member of the graft, resulted in leaf-sheat...

  14. Gibberellin is required for the formation of tension wood and stem gravitropism in Acacia mangium seedlings.

    Science.gov (United States)

    Nugroho, Widyanto Dwi; Yamagishi, Yusuke; Nakaba, Satoshi; Fukuhara, Shiori; Begum, Shahanara; Marsoem, Sri Nugroho; Ko, Jae-Heung; Jin, Hyun-O; Funada, Ryo

    2012-09-01

    Angiosperm trees generally form tension wood on the upper sides of leaning stems. The formation of tension wood is an important response to gravitational stimulus. Gibberellin appears to be involved in the differentiation of secondary xylem, but it remains unclear whether gibberellin plays a key role in the formation of tension wood and plant gravitropism. Therefore, a study was designed to investigate the effects of gibberellin and of inhibitors of the synthesis of gibberellin, namely paclobutrazole and uniconazole-P, on the formation of tension wood and negative stem gravitropism in Acacia mangium seedlings. Gibberellic acid (GA(3)), paclobutrazole and uniconazole-P were applied to seedlings via the soil in which they were growing. Distilled water was applied similarly as a control. Three days after such treatment, seedlings were tilted at an angle of 45° from the vertical, and samples of stems were collected for analysis 2 weeks, 2 months and 6 months after tilting. The effects of treatments on the stem recovery degree (Rº) were analysed as an index of the negative gravitropism of seedlings, together the width of the region of tension wood in the upper part of inclined stems. It was found that GA(3) stimulated the negative gravitropism of tilted seedling stems of A. mangium, while paclobutrazole and uniconazole-P inhibited recovery to vertical growth. Moreover, GA(3) stimulated the formation of tension wood in tilted A. mangium seedlings, while paclobutrazole and uniconazole-P strongly suppressed the formation of tension wood, as assessed 2 weeks after tilting. The results suggest that gibberellin plays an important role at the initial stages of formation of tension wood and in stem gravitropism in A. mangium seedlings in response to a gravitational stimulus.

  15. [Mutual Effect on Determination of Gibberellins and Glyphosate in Groundwater by Spectrophotometry].

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    Zhang, Li; Chen, Liang; Liu, Fei

    2015-04-01

    In the present study, a spectrophotometry method for the simultaneous determination of gibberellins (GA3) and glyphosate in groundwater was established and optimized. In addition, the mutual effect on simultaneous determination of GA3 and glyphosate was studied. Based on the experiment, good linearity (R2 > 0.99) was obtained for GA3 in the range of 0-20 and 0-100 µg and for glyphosate in the range of 0-8 and 5-15 µg. The method's detection limit (MDL) of GA3 and glyphosate was 0.48 and 0.82 µg, respectively; and the recovery rates of 15 to 150 µg GA3 and 3 to 10 µg glyphosate in all samples at a spiked level were 71.3% ± 1.9% and 98.4% ± 8.1%, respectively. No obvious influence of glyphosate (0-100 mg · L(-1)) on the recovery rates of GA3 was observed, but the presence of glyphosate could cause slight determination precision decrease of GA3. Meanwhile, adding 2 mg · L(-1) GA3 can increase the recovery rate of glyphosate.

  16. Overexpression of gibberellin 20-oxidase1 from Pinus densiflora results in enhanced wood formation with gelatinous fiber development in a transgenic hybrid poplar.

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    Park, Eung-Jun; Kim, Hyun-Tae; Choi, Young-Im; Lee, Chanhui; Nguyen, Van Phap; Jeon, Hyung-Woo; Cho, Jin-Seong; Funada, Ryo; Pharis, Richard P; Kurepin, Leonid V; Ko, Jae-Heung

    2015-11-01

    Gibberellins (GAs) are important regulators of plant shoot biomass growth, and GA 20-oxidase (GA20ox) is one of the major regulatory enzymes in the GA biosynthetic pathway. Previously, we showed that the expression levels of a putative GA20ox1 (i.e., PdGA20ox1) in stem tissue of 3-month-old seedlings of 12 families of Pinus densiflora were positively correlated with stem diameter growth across those same families growing in an even-aged 32-year-old pine forest (Park EJ, Lee WY, Kurepin LV, Zhang R, Janzen L, Pharis RP (2015) Plant hormone-assisted early family selection in Pinus densiflora via a retrospective approach. Tree Physiol 35:86-94). To further investigate the molecular function of this gene in the stem wood growth of forest trees, we produced transgenic poplar lines expressing PdGA20ox1 under the control of the 35S promoter (designated as 35S::PdGA20ox1). By age 3 months, most of the 35S::PdGA20ox1 poplar trees were showing an exceptional enhancement of stem wood growth, i.e., up to fourfold increases in stem dry weight, compared with the nontransformed control poplar plants. Significant increases in endogenous GA1, its immediate precursor (GA20) and its catabolite (GA8) in elongating internode tissue accompanied the increased stem growth in the transgenic lines. Additionally, the development of gelatinous fibers occurred in vertically grown stems of the 35S::PdGA20ox1 poplars. An analysis of the cell wall monosaccharide composition of the 35S::PdGA20ox1 poplars showed significant increases in xylose and glucose contents, indicating a qualitative increase in secondary wall depositions. Microarray analyses led us to find a total of 276 probe sets that were upregulated (using threefold as a threshold) in the stem tissues of 35S::PdGA20ox1 poplars relative to the controls. 'Cell organization or biogenesis'- and 'cell wall'-related genes were overrepresented, including many of genes that are involved in cell wall modification. Several transcriptional

  17. Plant hormones in arbuscular mycorrhizal symbioses: an emerging role for gibberellins

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    Foo, Eloise; Ross, John J.; Jones, William T.; Reid, James B.

    2013-01-01

    Background and Aims Arbuscular mycorrhizal symbioses are important for nutrient acquisition in >80 % of terrestrial plants. Recently there have been major breakthroughs in understanding the signals that regulate colonization by the fungus, but the roles of the known plant hormones are still emerging. Here our understanding of the roles of abscisic acid, ethylene, auxin, strigolactones, salicylic acid and jasmonic acid is discussed, and the roles of gibberellins and brassinosteroids examined. Methods Pea mutants deficient in gibberellins, DELLA proteins and brassinosteroids are used to determine whether fungal colonization is altered by the level of these hormones or signalling compounds. Expression of genes activated during mycorrhizal colonization is also monitored. Key Results Arbuscular mycorrhizal colonization of pea roots is substantially increased in gibberellin-deficient na-1 mutants compared with wild-type plants. This is reversed by application of GA3. Mutant la cry-s, which lacks gibberellin signalling DELLA proteins, shows reduced colonization. These changes were parallelled by changes in the expression of genes associated with mycorrhizal colonization. The brassinosteroid-deficient lkb mutant showed no change in colonization. Conclusions Biologically active gibberellins suppress arbuscule formation in pea roots, and DELLA proteins are essential for this response, indicating that this role occurs within the root cells. PMID:23508650

  18. Storage behavior and changes in concentrations of abscisic acid and gibberellins during dormancy break and germination in seeds of Phellodendron amurense var. wilsonii (Rutaceae).

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    Chen, Shun-Ying; Chien, Ching-Te; Baskin, Jerry M; Baskin, Carol C

    2010-02-01

    The medicinal Asian plant genus Phellodendron is known to contain several very important compounds that have biological action. The main purpose of this study was to determine whether seeds of Phellodendron amurense var. wilsonii can be stored and to characterize their dormancy. Seeds of this taxon stored at -20 and -80 degrees C and in liquid nitrogen retained their high germinability, indicating that they have orthodox storage behavior. Intact seeds from freshly collected fruits were dormant and required 12 weeks of cold stratification at 4 degrees C for complete germination. Scarifying the seed coat was partially effective in breaking seed dormancy. Exogenous gibberellins (GA(3), GA(4) and GA(4+7)) promoted germination of scarified seeds, GA(4) and GA(4+7) being more effective than GA(3). Fluridone, an abscisic acid (ABA) biosynthesis inhibitor, was efficient in breaking dormancy, but it was less effective than GA(4) or GA(4+7) alone. Paclobutrazol, a GA biosynthesis inhibitor, inhibited seed germination, and the inhibitory effect was reversed completely by GA(4) and by GA(4+7). ABA content of seeds subjected to cold stratification or to incubation at 35/10 degrees C, which enhanced seed germination, was reduced about four- to sixfold compared to that of fresh seeds. Higher concentrations of GA(3), GA(4) and GA(7) were detected in nondormant seeds and in seeds with an emerged radicle than in fresh seeds. Present results seem to indicate that dormancy in P. amurense var. wilsonii seeds is imposed partially by the seed coat and partially by high ABA content. ABA content decreased and GA(3), GA(4) and GA(7) content increased during germination.

  19. Chemical screening and development of novel gibberellin mimics.

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    Jiang, Kai; Shimotakahara, Hiroaki; Luo, Ming; Otani, Masato; Nakamura, Hidemitsu; Moselhy, Said Salama; Abualnaja, Khalid Omer; Al-Malki, Abdulrahman Labeed; Kumosani, Taha Abduallah; Kitahata, Nobutaka; Nakano, Takeshi; Nakajima, Masatoshi; Asami, Tadao

    2017-08-15

    Gibberellin (GA) plays versatile roles in the regulation of plant growth and development and therefore is widely used as a regulator in agriculture. We performed a chemical library screening and identified a chemical, named 67D, as a stimulator of seed germination that was suppressed by paclobutrazol (PAC), a GA biosynthesis inhibitor. In vitro binding assays indicated that 67D binds to the GID1 receptor. Further studies on the structure-activity relationship identified a chemical, named chemical 6, that strongly promoted seed germination suppressed by PAC. Chemical 6 was further confirmed to promote the degradation of RGA (for repressor of ga1-3), a DELLA protein, and suppress the expression levels of GA3ox1 in the same manner as GA does. 67D and its analogs are supposed to be agonists of GID1 and are expected to be utilized in agriculture and basic research as an alternative to GA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Exogenous GA3 application can compensate the morphogenetic effects of the GA-responsive dwarfing gene Rht12 in bread wheat.

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    Liang Chen

    Full Text Available The most common dwarfing genes in wheat, Rht-B1b and Rht-D1b, classified as gibberellin-insensitive (GAI dwarfing genes due to their reduced response to exogenous GA, have been verified as encoding negative regulators of gibberellin signaling. In contrast, the response of gibberellin-responsive (GAR dwarfing genes, such as Rht12, to exogenous GA is still unclear and the role of them, if any, in GA biosynthesis or signaling is unknown. The responses of Rht12 to exogenous GA3 were investigated on seedling vigour, spike phenological development, plant height and other agronomic traits, using F2 ∶ 3 and F3 ∶ 4 lines derived from a cross between Ningchun45 and Karcagi-12 in three experiments. The application of exogenous GA3 significantly increased coleoptile length and seedling leaf 1 length and area. While there was no significant difference between the dwarf and the tall lines at the seedling stage in the responsiveness to GA3, plant height was significantly increased, by 41 cm (53% averaged across the three experiments, in the GA3-treated Rht12 dwarf lines. Plant height of the tall lines was not affected significantly by GA3 treatment (<10 cm increased. Plant biomass and seed size of the GA3-treated dwarf lines was significantly increased compared with untreated dwarf plants while there was no such difference in the tall lines. GA3-treated Rht12 dwarf plants with the dominant Vrn-B1 developed faster than untreated plants and reached double ridge stage 57 days, 11 days and 50 days earlier and finally flowered earlier by almost 7 days while the GA3-treated tall lines flowering only 1-2 days earlier than the untreated tall lines. Thus, it is clear that exogenous GA3 can break the masking effect of Rht12 on Vrn-B1 and also restore other characters of Rht12 to normal. It suggested that Rht12 mutants may be deficient in GA biosynthesis rather than in GA signal transduction like the GA-insensitive dwarfs.

  1. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    Science.gov (United States)

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

    2015-09-01

    The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.

  2. Oligo-carrageenan kappa-induced reducing redox status and activation of TRR/TRX system increase the level of indole-3-acetic acid, gibberellin A3 and trans-zeatin in Eucalyptus globulus trees.

    Science.gov (United States)

    González, Alberto; Contreras, Rodrigo A; Zúiga, Gustavo; Moenne, Alejandra

    2014-08-20

    Eucalyptus globulus trees treated with oligo-carrageenan (OC) kappa showed an increase in NADPH, ascorbate and glutathione levels and activation of the thioredoxin reductase (TRR)/thioredoxin (TRX) system which enhance photosynthesis, basal metabolism and growth. In order to analyze whether the reducing redox status and the activation of thioredoxin reductase (TRR)/thioredoxin (TRX) increased the level of growth-promoting hormones, trees were treated with water (control), with OC kappa, or with inhibitors of ascorbate synthesis, lycorine, glutathione synthesis, buthionine sulfoximine (BSO), NADPH synthesis, CHS-828, and thioredoxin reductase activity, auranofine, and with OC kappa, and cultivated for four additional months. Eucalyptus trees treated with OC kappa showed an increase in the levels of the auxin indole 3-acetic acid (IAA), gibberellin A3 (GA3) and the cytokinin trans-zeatin (t-Z) as well as a decrease in the level of the brassinosteroid epi-brassinolide (EB). In addition, treatment with lycorine, BSO, CHS-828 and auranofine inhibited the increase in IAA, GA3 and t-Z as well as the decrease in EB levels. Thus, the reducing redox status and the activation of TRR/TRX system induced by OC kappa increased the levels of IAA, GA3 and t-Z levels determining, at least in part, the stimulation of growth in Eucalyptus trees.

  3. Decorative value of three dahlia cultivars (Dahlia ×cultorum Thorsr. et Reis treated with gibberellin

    Directory of Open Access Journals (Sweden)

    Krystyna Pudelska

    2013-04-01

    Full Text Available Dahlia (Dalia ×cultorumThorsr. et Reis is a perennial that due to special decorative value, diversity of inflorescences colours and shapes as well as plants height, is widely planted in flowerbeds, borders and different garden containers. Growth regulators play a significant role in ornamental plants cultivation. They influence size and shape of plants, number of inflorescences and flowering earliness. Gibberellins are among substances that are commonly used in plants production. In the years 2010-2011 research on the effect of GA 3 on morphological features of 3 Polish dahlia cultivars of Top-Mix group was conducted.

  4. Gibberellin and cytokinin effects on soybean growth Giberelina e citocinina no crescimento da soja

    Directory of Open Access Journals (Sweden)

    Vagner Maximino Leite

    2003-01-01

    Full Text Available Soybean is an important crop in Brazil. Nonetheless, there are no reports on the use of plant growth regulator potential in relation to this crop in the national literature. To better understand the role of these compounds, a pot experiment was carried out to study effects of GA3 and cytokinin on the vegetative growth of the soybean. GA3 (50 mg L-1 was applied as seed treatment, leaving plants with water application as control. GA3 (100 mg L-1 and cytokinin (30 mg L-1 were sprayed on leaves at the physiological stage V3/V4, and 15 days after, cytokinin (30 mg L-1, also as foliar spray. Seed treatment decreased plant emergence and initial soybean root growth, but as the season progressed, differences in root growth disappeared; plants were shorter, and presented a decrease in the number of nodes, in stem diameter, in leaf area and in dry matter yield. Conversely, foliar application of GA3 led to an increase in plant height, first node height and stem diameter. Leaf area and dry matter production also increased as a result of GA3 foliar application. There was no effect of exogenous gibberellin and cytokinin on the number of soybean leaves, number of stem branches and root dry matter. Joint application of gibberellin and cytokinin tended to inhibit gibberellin effects. Cytokinin applied to leaves during soybean vegetative growth was not effective in modifying any of the evaluated plant growth variables.A soja é uma das principais culturas no Brasil, porém não há relatos do potencial de utilização dos fitorreguladores nessa cultura na literatura nacional. Para saber mais sobre estes compostos, um experimento em vasos foi conduzido para estudar o efeito do GA3 e citocinina (CK sobre o crescimento vegetativo e floração da soja. GA3 (50 mg L-1 foi aplicado como tratamento de sementes. Plantas somente com aplicação de água foram aplicadas como controle. Foram feitas duas aplicações foliares, sendo na primeira aplicado 100 mg L-1 de GA3

  5. RNA sequencing reveals high resolution expression change of major plant hormone pathway genes after young seedless grape berries treated with gibberellin.

    Science.gov (United States)

    Chai, Lijuan; Li, Yanmei; Chen, Shangwu; Perl, Avihai; Zhao, Fengxia; Ma, Huiqin

    2014-12-01

    Seedless varieties are of particular importance to the table-grape and raisin industries. Gibberellin (GA) application is widely used in the early stages of seedless berry development to increase berry size and economic value. However, the underlying mechanism of GA induction of berry enlargement is not well understood. Here, RNA-sequencing analysis of 'Centennial Seedless' (Vitis vinifera L.) berries treated with GA3 12 days after flowering is reported. Pair-wise comparison of GA3-treated and control samples detected 165, 444, 463 genes with an over two-fold change in expression 1, 3, and 7 days after GA3 treatment, respectively. The number of differentially expressed genes increased with time after GA3 treatment, and the differential expression was dominated by downregulation. Significantly modulated expression included genes encoding synthesis and catabolism to manage plant hormone homeostasis, hormone transporters, receptors and key components in signaling pathways; exogenous GA3 induced multipoint cross talk with auxin, cytokinin, brassinosteroid, ABA and ethylene. The temporal gene-expression patterns of cell-wall-modification enzymes, cytoskeleton and membrane components and transporters revealed a pivotal role for cell-wall-relaxation genes in GA3-induced berry enlargement. Our results provide the first sequential transcriptomic atlas of exogenous GA3-induced berry enlargement and reveal the complexity of GA3's effect on berry sizing. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Gibberellins and Seed Development in Maize. I. Evidence That Gibberellin/Abscisic Acid Balance Governs Germination versus Maturation Pathways1

    Science.gov (United States)

    White, Constance N.; Proebsting, William M.; Hedden, Peter; Rivin, Carol J.

    2000-01-01

    Abscisic acid (ABA) is required for the regulation of seed maturation in maize (Zea mays L.). Mutants blocked in ABA synthesis (such as viviparous-5) do not mature to quiescent, desiccation-tolerant seeds, but germinate on the ear midway through kernel development. Because gibberellins (GA) and ABA act antagonistically in many aspects of plant development, we hypothesized that ABA antagonizes a positive GA signal for precocious germination in maize. In these experiments, we show that a GA deficiency early in seed development, induced genetically or via biosynthesis inhibitors, suppresses vivipary in ABA-deficient developing kernels. The resulting seeds have both desiccation tolerance and storage longevity. Temporal analysis of GA accumulation in wild-type kernels revealed the accumulation of bioactive GA1 and GA3 prior to the peak in ABA content. We speculate that these GAs stimulate a developmental program leading to vivipary in the absence of normal amounts of ABA, and that a reduction of GA content re-establishes an ABA/GA ratio appropriate for suppression of germination and induction of maturation. In contrast, the induction of a GA deficiency did not suppress vivipary in viviparous-1 mutant kernels, suggesting that VP1 acts downstream of both GA and ABA in programming seed development. PMID:10759503

  7. Morphological Performance of Onion under Exogenous Treatments of GA3

    Directory of Open Access Journals (Sweden)

    Md.Dulal SARKAR

    2018-03-01

    Full Text Available The present study was conducted to assess the morphological response of onion plants to different GA3 levels (0, 20, 40 and 60 ppm. The factor levels of GA3 were applied during transplanting by root soaking and foliar spray at 30 and 60 days after transplanting. The gibberellic acid had a great effect on increasing plant height (46.50 cm, shoot biomass (641.67 g m-2, bulb biomass (1125.00 g m-2 and also dry matter accumulation in onion plants under the effect of 60 ppm compared to control. Plants grown up without GA3 application were shorter than those grown with GA3 spray where the lowest plant height (34.67 cm was remarked. The leaf number (11.43 was considerably increased when 60 ppm GA3 was used as the growth promoter factor in comparison to control. The plants attain minimum fresh biomass at harvesting time in the shoot (441.67 g m-2 and bulb (641.67 g m-2 grown in control plot. Considerably (41.63% more dry shoot biomass accumulation was recorded in 60 ppm GA3 treated plants in comparison with the control at harvesting stages. Insignificant effect by all concentration of GA3 was found in bulb length, fresh root biomass and dry root biomass. Thus, the use of 60 ppm GA3 can be recommend for onion production due to the significantly increased of the fresh bulb biomass with about 42.96% over control.

  8. Carbohydrates and gibberellins relationship in potato tuberization

    Czech Academy of Sciences Publication Activity Database

    Ševčíková, H.; Mašková, P.; Tarkowská, Danuše; Mašek, T.; Lipavská, H.

    2017-01-01

    Roč. 214, JUL (2017), s. 53-63 ISSN 0176-1617 R&D Projects: GA ČR GA14-34792S Institutional support: RVO:61389030 Keywords : Carbohydrate distribution * Gibberellin * Photoautotrophic cultivation * Potato * Tuberization Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Plant sciences, botany Impact factor: 3.121, year: 2016

  9. Genome-Wide Analysis of the Biosynthesis and Deactivation of Gibberellin-Dioxygenases Gene Family in Camellia sinensis (L. O. Kuntze

    Directory of Open Access Journals (Sweden)

    Cheng Pan

    2017-09-01

    Full Text Available Gibberellins (GAs, a class of diterpenoid phytohormones, play a key role in regulating diverse processes throughout the life cycle of plants. Bioactive GA levels are rapidly regulated by Gibberellin-dioxygenases (GAox, which are involved in the biosynthesis and deactivation of gibberellin. In this manuscript, a comprehensive genome-wide analysis was carried out to find all GAox in Camellia sinensis. For the first time in a tea plant, 14 CsGAox genes, containing two domains, DIOX_N (PF14226 and 2OG-FeII_Oxy, were identified (PF03171. These genes all belong to 2-oxoglutarate-dependent dioxygenases (2-ODD, including four CsGA20ox (EC: 1.14.11.12, three CsGA3ox (EC: 1.14.11.15, and seven CsGA2ox (EC: 1.14.11.13. According to the phylogenetic classification as in Arabidopsis, the CsGAox genes spanned five subgroups. Each CsGAox shows tissue-specific expression patterns, although these vary greatly. Some candidate genes, which may play an important role in response to external abiotic stresses, have been identified with regards to patterns, such as CsGA20ox2, CsGA3ox2, CsGA3ox3, CsGA2ox1, CsGA2ox2, and CsGA2ox4. The bioactive GA levels may be closely related to the GA20ox, GA3ox and GA2ox genes. In addition, the candidate genes could be used as marker genes for abiotic stress resistance breeding in tea plants.

  10. Stamen-derived bioactive gibberellin is essential for male flower development of Cucurbita maxima L.

    Science.gov (United States)

    Pimenta Lange, Maria João; Knop, Nicole; Lange, Theo

    2012-04-01

    Gibberellin (GA) signalling during pumpkin male flower development is highly regulated, including biosynthetic, perception, and transduction pathways. GA 20-oxidases, 3-oxidases, and 2-oxidases catalyse the final part of GA synthesis. Additionally, 7-oxidase initiates this part of the pathway in some cucurbits including Cucurbita maxima L. (pumpkin). Expression patterns for these GA-oxidase-encoding genes were examined by competitive reverse transcription-PCR (RT-PCR) and endogenous GA levels were determined during pumpkin male flower development. In young flowers, GA20ox3 transcript levels are high in stamens, followed by high levels of the GA precursor GA(9). Later, just before flower opening, transcript levels for GA3ox3 and GA3ox4 increase in the hypanthium and stamens, respectively. In the stamen, following GA3ox4 expression, bioactive GA(4) levels rise dramatically. Accordingly, catabolic GA2ox2 and GA2ox3 transcript levels are low in developing flowers, and increase in mature flowers. Putative GA receptor GID1b and DELLA repressor GAIPb transcript levels do not change in developing flowers, but increase sharply in mature flowers. Emasculation arrests floral development completely and leads to abscission of premature flowers. Application of GA(4) (but not of its precursors GA(12)-aldehyde or GA(9)) restores normal growth of emasculated flowers. These results indicate that de novo GA(4) synthesis in the stamen is under control of GA20ox3 and GA3ox4 genes just before the rapid flower growth phase. Stamen-derived bioactive GA is essential and sufficient for male flower development, including the petal and the pedicel growth.

  11. The gene pat-2, which induces natural parthenocarpy, alters the gibberellin content in unpollinated tomato ovaries.

    Science.gov (United States)

    Fos, M; Nuez, F; García-Martínez, J L

    2000-02-01

    We investigated the role of gibberellins (GAs) in the effect of pat-2, a recessive mutation that induces facultative parthenocarpic fruit development in tomato (Lycopersicon esculentum Mill.) using near-isogenic lines with two different genetic backgrounds. Unpollinated wild-type Madrigal (MA/wt) and Cuarenteno (CU/wt) ovaries degenerated, but GA(3) application induced parthenocarpic fruit growth. On the contrary, parthenocarpic growth of MA/pat-2 and CU/pat-2 fruits, which occurs in the absence of pollination and hormone application, was not affected by GA(3). Pollinated MA/wt and parthenocarpic MA/pat-2 ovary development was negated by paclobutrazol, and this inhibitory effect was counteracted by GA(3). The main GAs of the early-13-hydroxylation pathway (GA(1), GA(3), GA(8), GA(19), GA(20), GA(29), GA(44), GA(53), and, tentatively, GA(81)) and two GAs of the non-13-hydroxylation pathway (GA(9) and GA(34)) were identified in MA/wt ovaries by gas chromatography-selected ion monitoring. GAs were quantified in unpollinated ovaries at flower bud, pre-anthesis, and anthesis. In unpollinated MA/pat-2 and CU/pat-2 ovaries, the GA(20) content was much higher (up to 160 times higher) and the GA(19) content was lower than in the corresponding non-parthenocarpic ovaries. The application of an inhibitor of 2-oxoglutarate-dependent dioxygenases suggested that GA(20) is not active per se. The pat-2 mutation may increase GA 20-oxidase activity in unpollinated ovaries, leading to a higher synthesis of GA(20), the precursor of an active GA.

  12. Expression Studies of Gibberellin Oxidases in Developing Pumpkin Seeds1

    Science.gov (United States)

    Frisse, Andrea; Pimenta, Maria João; Lange, Theo

    2003-01-01

    Two cDNA clones, 3-ox and 2-ox, have been isolated from developing pumpkin (Cucurbita maxima) embryos that show significant amino acid homology to gibberellin (GA) 3-oxidases and 2-oxidases, respectively. Recombinant fusion protein of clone 3-ox converted GA12-aldehyde, GA12, GA15, GA24, GA25, and GA9 to GA14-aldehyde, GA14, GA37, GA36, GA13, and GA4, respectively. Recombinant 2-ox protein oxidized GA9, GA4, and GA1 to GA51, GA34, and GA8, respectively. Previously cloned GA 7-oxidase revealed additional 3β-hydroxylation activity of GA12. Transcripts of this gene were identified in endosperm and embryo of the developing seed by quantitative reverse transcriptase-polymerase chain reaction and localized in protoderm, root apical meristem, and quiescent center by in situ hybridization. mRNA of the previously cloned GA 20-oxidase from pumpkin seeds was localized in endosperm and in tissues of protoderm, ground meristem, and cotyledons of the embryo. However, transcripts of the recently cloned GA 20-oxidase from pumpkin seedlings were found all over the embryo, and in tissues of the inner seed coat at the micropylar end. Previously cloned GA 2β,3β-hydroxylase mRNA molecules were specifically identified in endosperm tissue. Finally, mRNA molecules of the 3-ox and 2-ox genes were found in the embryo only. 3-ox transcripts were localized in tissues of cotyledons, protoderm, and inner cell layers of the root apical meristem, and 2-ox transcripts were found in all tissues of the embryo except the root tips. These results indicate tissue-specific GA-biosynthetic pathways operating within the developing seed. PMID:12644672

  13. Evolutionary rate patterns of the Gibberellin pathway genes

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    Zhang Fu-min

    2009-08-01

    Full Text Available Abstract Background Analysis of molecular evolutionary patterns of different genes within metabolic pathways allows us to determine whether these genes are subject to equivalent evolutionary forces and how natural selection shapes the evolution of proteins in an interacting system. Although previous studies found that upstream genes in the pathway evolved more slowly than downstream genes, the correlation between evolutionary rate and position of the genes in metabolic pathways as well as its implications in molecular evolution are still less understood. Results We sequenced and characterized 7 core structural genes of the gibberellin biosynthetic pathway from 8 representative species of the rice tribe (Oryzeae to address alternative hypotheses regarding evolutionary rates and patterns of metabolic pathway genes. We have detected significant rate heterogeneity among 7 GA pathway genes for both synonymous and nonsynonymous sites. Such rate variation is mostly likely attributed to differences of selection intensity rather than differential mutation pressures on the genes. Unlike previous argument that downstream genes in metabolic pathways would evolve more slowly than upstream genes, the downstream genes in the GA pathway did not exhibited the elevated substitution rate and instead, the genes that encode either the enzyme at the branch point (GA20ox or enzymes catalyzing multiple steps (KO, KAO and GA3ox in the pathway had the lowest evolutionary rates due to strong purifying selection. Our branch and codon models failed to detect signature of positive selection for any lineage and codon of the GA pathway genes. Conclusion This study suggests that significant heterogeneity of evolutionary rate of the GA pathway genes is mainly ascribed to differential constraint relaxation rather than the positive selection and supports the pathway flux theory that predicts that natural selection primarily targets enzymes that have the greatest control on fluxes.

  14. Ga 3 -Mediated Dormancy Alleviation In The Reputed African Potato ...

    African Journals Online (AJOL)

    In the ex vitro experiment, intact seeds were sown and left to germinate in a potting soil mix under greenhouse conditions. Results: Highest levels of germination (36.7-60.0% in the light and 36.7-46.7% in the dark) were achieved by treating mechanically scarified seeds with GA3 at various concentrations for 24 h. This was ...

  15. Role of gibberellins in parthenocarpic fruit development induced by the genetic system pat-3/pat-4 in tomato.

    Science.gov (United States)

    Fos, Mariano; Proaño, Karina; Nuez, Fernando; García-Martínez, José L.

    2001-04-01

    The role of gibberellins (GAs) in the induction of parthenocarpic fruit-set and growth by the pat-3/pat-4 genetic system in tomato (Lycopersicon esculentum Mill.) was investigated using wild type (WT; Cuarenteno) and a near-isogenic line derived from the German line RP75/59 (the source of pat-3/pat-4 parthenocarpy). Unpollinated WT ovaries degenerated but GA3 application induced parthenocarpic fruit growth. On the contrary, parthenocarpic growth of pat-3/pat-4 fruits, which occurs in the absence of pollination and hormone treatment, was not affected by applied GA3. Unpollinated pat-3/pat-4 fruit growth was negated by paclobutrazol, an inhibitor of ent-kaurene oxidase, and this inhibitory effect was negated by GA3. The quantification of the main GAs of the early 13-hydroxylation pathway (GA1, GA8, GA19, GA20, GA29 and GA44) in unpollinated ovaries at 3 developmental stages (flower bud, FB; pre-anthesis, PR; and anthesis, AN), by gas chromatography-selected ion monitoring, showed that the concentration of most of them was higher in pat-3/pat-4 than in WT ovaries at PR and AN stages. The concentration of GA1, suggested previously to be the active GA in tomate, was 2-4 times higher. Unpollinated pat-3/pat-4 ovaries at FB, PR and AN stages also contained relatively high amounts (5-12 ng g-1) of GA3, a GA found at less than 0.5 ng g-1 in WT ovaries. It is concluded that the mutations pat-3/pat-4 may induce natural facultative parthenocarpy capacity in tomato by increasing the concentration of GA1 and GA3 in the ovaries before pollination.

  16. Gibberellin mediates daylength-controlled differentiation of vegetative meristems in strawberry (Fragaria x ananassa Duch).

    Science.gov (United States)

    Hytönen, Timo; Elomaa, Paula; Moritz, Thomas; Junttila, Olavi

    2009-02-11

    Differentiation of long and short shoots is an important developmental trait in several species of the Rosaceae family. However, the physiological mechanisms controlling this differentiation are largely unknown. We have studied the role of gibberellin (GA) in regulation of shoot differentiation in strawberry (Fragaria x ananassa Duch.) cv. Korona. In strawberry, differentiation of axillary buds to runners (long shoot) or to crown branches (short shoot) is promoted by long-day and short-day conditions, respectively. Formation of crown branches is a prerequisite for satisfactory flowering because inflorescences are formed from the apical meristems of the crown. We found that both prohexadione-calcium and short photoperiod inhibited runner initiation and consequently led to induction of crown branching. In both cases, this correlated with a similar decline in GA1 level. Exogenous GA3 completely reversed the effect of prohexadione-calcium in a long photoperiod, but was only marginally effective in short-day grown plants. However, transfer of GA3-treated plants from short days to long days restored the normal runner formation. This did not occur in plants that were not treated with GA3. We also studied GA signalling homeostasis and found that the expression levels of several GA biosynthetic, signalling and target genes were similarly affected by prohexadione-calcium and short photoperiod in runner tips and axillary buds, respectively. GA is needed for runner initiation in strawberry, and the inhibition of GA biosynthesis leads to the formation of crown branches. Our findings of similar changes in GA levels and in GA signalling homeostasis after prohexadione-calcium and short-day treatments, and photoperiod-dependent responsiveness of the axillary buds to GA indicate that GA plays a role also in the photoperiod-regulated differentiation of axillary buds. We propose that tightly regulated GA activity may control induction of cell division in subapical tissues of axillary

  17. Gibberellin mediates daylength-controlled differentiation of vegetative meristems in strawberry (Fragaria × ananassa Duch

    Directory of Open Access Journals (Sweden)

    Moritz Thomas

    2009-02-01

    Full Text Available Abstract Background Differentiation of long and short shoots is an important developmental trait in several species of the Rosaceae family. However, the physiological mechanisms controlling this differentiation are largely unknown. We have studied the role of gibberellin (GA in regulation of shoot differentiation in strawberry (Fragaria × ananassa Duch. cv. Korona. In strawberry, differentiation of axillary buds to runners (long shoot or to crown branches (short shoot is promoted by long-day and short-day conditions, respectively. Formation of crown branches is a prerequisite for satisfactory flowering because inflorescences are formed from the apical meristems of the crown. Results We found that both prohexadione-calcium and short photoperiod inhibited runner initiation and consequently led to induction of crown branching. In both cases, this correlated with a similar decline in GA1 level. Exogenous GA3 completely reversed the effect of prohexadione-calcium in a long photoperiod, but was only marginally effective in short-day grown plants. However, transfer of GA3-treated plants from short days to long days restored the normal runner formation. This did not occur in plants that were not treated with GA3. We also studied GA signalling homeostasis and found that the expression levels of several GA biosynthetic, signalling and target genes were similarly affected by prohexadione-calcium and short photoperiod in runner tips and axillary buds, respectively. Conclusion GA is needed for runner initiation in strawberry, and the inhibition of GA biosynthesis leads to the formation of crown branches. Our findings of similar changes in GA levels and in GA signalling homeostasis after prohexadione-calcium and short-day treatments, and photoperiod-dependent responsiveness of the axillary buds to GA indicate that GA plays a role also in the photoperiod-regulated differentiation of axillary buds. We propose that tightly regulated GA activity may control

  18. Gibberellin mediates daylength-controlled differentiation of vegetative meristems in strawberry (Fragaria × ananassa Duch)

    Science.gov (United States)

    Hytönen, Timo; Elomaa, Paula; Moritz, Thomas; Junttila, Olavi

    2009-01-01

    Background Differentiation of long and short shoots is an important developmental trait in several species of the Rosaceae family. However, the physiological mechanisms controlling this differentiation are largely unknown. We have studied the role of gibberellin (GA) in regulation of shoot differentiation in strawberry (Fragaria × ananassa Duch.) cv. Korona. In strawberry, differentiation of axillary buds to runners (long shoot) or to crown branches (short shoot) is promoted by long-day and short-day conditions, respectively. Formation of crown branches is a prerequisite for satisfactory flowering because inflorescences are formed from the apical meristems of the crown. Results We found that both prohexadione-calcium and short photoperiod inhibited runner initiation and consequently led to induction of crown branching. In both cases, this correlated with a similar decline in GA1 level. Exogenous GA3 completely reversed the effect of prohexadione-calcium in a long photoperiod, but was only marginally effective in short-day grown plants. However, transfer of GA3-treated plants from short days to long days restored the normal runner formation. This did not occur in plants that were not treated with GA3. We also studied GA signalling homeostasis and found that the expression levels of several GA biosynthetic, signalling and target genes were similarly affected by prohexadione-calcium and short photoperiod in runner tips and axillary buds, respectively. Conclusion GA is needed for runner initiation in strawberry, and the inhibition of GA biosynthesis leads to the formation of crown branches. Our findings of similar changes in GA levels and in GA signalling homeostasis after prohexadione-calcium and short-day treatments, and photoperiod-dependent responsiveness of the axillary buds to GA indicate that GA plays a role also in the photoperiod-regulated differentiation of axillary buds. We propose that tightly regulated GA activity may control induction of cell division in

  19. Strigolactone versus gibberellin signaling: reemerging concepts?

    Science.gov (United States)

    Wallner, Eva-Sophie; López-Salmerón, Vadir; Greb, Thomas

    2016-06-01

    In this review, we compare knowledge about the recently discovered strigolactone signaling pathway and the well established gibberellin signaling pathway to identify gaps of knowledge and putative research directions in strigolactone biology. Communication between and inside cells is integral for the vitality of living organisms. Hormonal signaling cascades form a large part of this communication and an understanding of both their complexity and interactive nature is only beginning to emerge. In plants, the strigolactone (SL) signaling pathway is the most recent addition to the classically acting group of hormones and, although fundamental insights have been made, knowledge about the nature and impact of SL signaling is still cursory. This narrow understanding is in spite of the fact that SLs influence a specific spectrum of processes, which includes shoot branching and root system architecture in response, partly, to environmental stimuli. This makes these hormones ideal tools for understanding the coordination of plant growth processes, mechanisms of long-distance communication and developmental plasticity. Here, we summarize current knowledge about SL signaling and employ the well-characterized gibberellin (GA) signaling pathway as a scaffold to highlight emerging features as well as gaps in our knowledge in this context. GA signaling is particularly suitable for this comparison because both signaling cascades share key features of hormone perception and of immediate downstream events. Therefore, our comparative view demonstrates the possible level of complexity and regulatory interfaces of SL signaling.

  20. Cloning of gibberellin 3 beta-hydroxylase cDNA and analysis of endogenous gibberellins in the developing seeds in watermelon.

    Science.gov (United States)

    Kang, Hong-Gyu; Jun, Sung-Hoon; Kim, Joonyul; Kawaide, Hiroshi; Kamiya, Yuji; An, Gynheung

    2002-02-01

    We have isolated Cv3h, a cDNA clone from the developing seeds of watermelon, and have demonstrated significant amino acid homology with gibberellin (GA) 3 beta-hydroxylases. This cDNA clone was expressed in Escherichia coli as a fusion protein that oxidized GA(9) and GA(12) to GA(4) and GA(14), respectively. The Cv3h protein had the highest similarity with pumpkin GA 2 beta,3 beta-hydroxylase, but did not possess 2 beta-hydroxylation function. RNA blot analysis showed that the gene was expressed primarily in the inner parts of developing seeds, up to 10 d after pollination (DAP). In the parthenocarpic fruits induced by treatment with 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU), the embryo and endosperm of the seeds were undeveloped, whereas the integumental tissues, of maternal origin, showed nearly normal development. Cv3h mRNA was undetectable in the seeds of CPPU-treated fruits, indicating that the GA 3 beta-hydroxylase gene was expressed in zygotic cells. In our analysis of endogenous GAs from developing seeds, GA(9) and GA(4) were detected at high levels but those of GA(20) and GA(1) were very low. This demonstrates that GA biosynthesis in seeds prefers a non-13-hydroxylation pathway over an early 13-hydroxylation pathway. We also analyzed endogenous GAs from seeds of the parthenocarpic fruits. The level of bioactive GA(4 )was much lower there than in normal seeds, indicating that bioactive GAs, unconnected with Cv3h, exist in integumental tissues during early seed development.

  1. Effect of GA3 on photosynthate allocation and invertase activity in radish plants grown on different potassium levels

    Directory of Open Access Journals (Sweden)

    Barbara Niemyska

    2014-01-01

    Full Text Available The effect of GA3 application to the swollen hypocotyl was studied in radish cultivars Saxa and Tetra Iłowiecka, supplied with various amount of K and grown in greenhouse in hydroponic culture. In low-K plants of both compared cultivars, strong depression of 14C02 assimilation preceded diminished export of current photosynthates. In plants with K+-deficit, transfer for 3 days from low- to high-K solution stimulated photosynthesis without effect on 14C-export. Three days after GA3 treatment of the swollen hypocotyl 14C02 assimilation was stimulated while 14C-retention in the blades was diminished, but only in low-K plants. In Tetra low-K plants with poorly developed storage organs, treatment with GA3 caused their better supply with current photosynthates at the expense of the roots. In the Saxa cultivar, the pattern of photosynthate allocation was only slightly affected by GA3 even in K-deficient plants; the swollen hypocotyl was already developed before K depletion from the nutrient solution. Nevertheless, in Saxa plants, GA3 prolonged not only growth of the storage organ, but also enhanced acid invertase which at that time was greatly diminished in low- and high-K plants. In contrast, the relatively high activity of invertase in Tetra cv. was not affected by GA3 treatment in low-K plants and was even depressed in high-K plants. This suggests that growth and accumulation of substances in the storage organ of radish plants and acid invertase activity greatly differ in their response to applied GAY

  2. Acides gras oméga-3 et dyslexie

    Science.gov (United States)

    Zelcer, Michal; Goldman, Ran D.

    2015-01-01

    Résumé Question À la lumière de la hausse du nombre d’enfants d’âge scolaire ayant reçu un diagnostic de dyslexie, quel est le rôle des suppléments d’acides gras oméga-3 dans la prise en charge de cette affection? Réponse La dyslexie est le trouble d’apprentissage le plus répandu et elle est connue pour ses causes multifactorielles. De récentes données probantes pointent vers une corrélation entre le métabolisme défectueux des acides gras polyinsaturés et les troubles de neurodéveloppement, tels que la dyslexie. Bien que l’administration de suppléments d’acides gras oméga-3 aux enfants dyslexiques ait fait l’objet d’études, les données probantes sont limitées. Les critères diagnostiques homogènes de dyslexie, les mesures objectives de carence en acides gras et la surveillance étroite de l’apport alimentaire ne sont que quelques-uns des facteurs pouvant améliorer la qualité de la recherche dans ce domaine.

  3. Molecular Characterization of Three GIBBERELLIN-INSENSITIVE DWARF2 Homologous Genes in Common Wheat.

    Directory of Open Access Journals (Sweden)

    XueYuan Lou

    Full Text Available F-box protein is a core component of the ubiquitin E3 ligase SCF complex and is involved in the gibberellin (GA signaling pathway. To elucidate the molecular mechanism of GA signaling in wheat, three homologous GIBBERELLIN-INSENSITIVE DWARF2 genes, TaGID2s, were isolated from the Chinese Spring wheat variety. A subcellular localization assay in onion epidermal cells and Arabidopsis mesophyll protoplasts showed that TaGID2s are localized in the nuclei. The expression profiles using quantitative real-time polymerase chain reaction showed that TaGID2s were downregulated by GA3. The interaction between TaGID2s and TSK1 (homologous to ASK1 in yeast indicated that TaGID2s might function as a component of an E3 ubiquitin-ligase SCF complex. Yeast two-hybrid assays showed that a GA-independent interaction occurred between three TaGID2s and RHT-A1a, RHT-B1a, and RHT-D1a. Furthermore, TaGID2s interact with most RHT-1s, such as RHT-B1h, RHT-B1i, RHT-D1e, RHT-D1f, etc., but cannot interact with RHT-B1b or RHT-B1e, which have a stop codon in the DELLA motif, resulting in a lack of a GRAS domain. In addition, RHT-B1k has a frame-shift mutation in the VHIID motif leading to loss of the LHRII motif in the GRAS domain and RHT-D1h has a missense mutation in the LHRII motif. These results indicate that TaGID2s, novel positive regulators of the GA response, recognize RHT-1s in the LHRII motif resulting in poly-ubiquitination and degradation of the DELLA protein.

  4. Overexpression of a Protein Phosphatase 2C from Beech Seeds in Arabidopsis Shows Phenotypes Related to Abscisic Acid Responses and Gibberellin Biosynthesis1

    Science.gov (United States)

    Reyes, David; Rodríguez, Dolores; González-García, Mary Paz; Lorenzo, Oscar; Nicolás, Gregorio; García-Martínez, José Luis; Nicolás, Carlos

    2006-01-01

    A functional abscisic acid (ABA)-induced protein phosphatase type 2C (PP2C) was previously isolated from beech (Fagus sylvatica) seeds (FsPP2C2). Because transgenic work is not possible in beech, in this study we overexpressed this gene in Arabidopsis (Arabidopsis thaliana) to provide genetic evidence on FsPP2C2 function in seed dormancy and other plant responses. In contrast with other PP2Cs described so far, constitutive expression of FsPP2C2 in Arabidopsis, under the cauliflower mosaic virus 35S promoter, produced enhanced sensitivity to ABA and abiotic stress in seeds and vegetative tissues, dwarf phenotype, and delayed flowering, and all these effects were reversed by gibberellic acid application. The levels of active gibberellins (GAs) were reduced in 35S:FsPP2C2 plants, although transcript levels of AtGA20ox1 and AtGA3ox1 increased, probably as a result of negative feedback regulation, whereas the expression of GASA1 was induced by GAs. Additionally, FsPP2C2-overexpressing plants showed a strong induction of the Responsive to ABA 18 (RAB18) gene. Interestingly, FsPP2C2 contains two nuclear targeting sequences, and transient expression assays revealed that ABA directed this protein to the nucleus. Whereas other plant PP2Cs have been shown to act as negative regulators, our results support the hypothesis that FsPP2C2 is a positive regulator of ABA. Moreover, our results indicate the existence of potential cross-talk between ABA signaling and GA biosynthesis. PMID:16815952

  5. Radioresistance of kohlrabi (Brassicaoleacea L., var. gongylodes L.) seeds in relation to the metabolism of indoles, auxins and gibberellins

    International Nuclear Information System (INIS)

    Vackova, K.; Kutacek, M.

    1976-01-01

    Irradiation of the seeds of radioresistant kohlrabi with gamma-rays at doses 50 to 300 kR resulted in a decrease in growth and a drop in tryptophan (Try) level in seven-day-old plants. The level of glucobrassicin (GLUBR), 3-indolylacetonitrile (IAN) and gibberellic acid (GA 3 ) in the plants increased up to a maximum with a dose of about 150-200 kR, afterwards it decreased. It is assumed that the specific system of auxin synthesis in Brassica plants played an important role in the reparation processes and thus also in the radioresistance of these plants. In contrast to the divergent systems of auxin biosynthesis in other plants which are damaged by lower doses of radiation, the specific system of auxin formation via GLUBR synthesis, under formation of IAN intermediate, is widely not attacked by radiation. Thus, these irradiated plants are supplied with auxins and with gibberellins, the both hormones having a radioprotective effect. (author)

  6. Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L. Assisted by Corynebacterium variabile.

    Directory of Open Access Journals (Sweden)

    Sen Yang

    Full Text Available The accumulation of a considerable quantity of gibberellin fermentation residue (GFR during gibberellic acid A3 (GA3 production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL and microbes (Corynebacterium variabile to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

  7. Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile.

    Science.gov (United States)

    Yang, Sen; Xie, Jiufeng; Hu, Nan; Liu, Yixiong; Zhang, Jiner; Ye, Xiaobin; Liu, Ziduo

    2015-01-01

    The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

  8. The role of gibberellins in improving the resistance of tebuconazole-coated maize seeds to chilling stress by microencapsulation

    Science.gov (United States)

    Yang, Lijuan; Yang, Daibin; Yan, Xiaojing; Cui, Li; Wang, Zhenying; Yuan, Huizhu

    2016-11-01

    Chilling stress during germination often causes severe injury. In the present study, maize seed germination and shoot growth under chilling stress were negatively correlated with the dose of tebuconazole in an exponential manner as predicted by the model Y = A + B × e(-x/k). Microencapsulation was an effective means of eliminating potential phytotoxic risk. The gibberellins (GAs) contents were higher after microencapsulation treatment than after conventional treatment when the dose of tebuconazole was higher than 0.12 g AI (active ingredient) kg-1 seed. Further analysis indicated that microencapsulation can stimulate ent-kaurene oxidase (KO) activity to some extent, whereas GA 3-oxidase (GA3ox) and GA 2-oxidase (GA2ox) activities remained similar to those in the control. Genes encoding GA metabolic enzymes exhibited different expression patterns. Transcript levels of ZmKO1 increased in the microcapsule treatments compared to the control. Even when incorporated into microcapsules, tebuconazole led to the upregulation of ZmGA3ox1 at doses of less than 0.12 g AI kg-1 seed and to the upregulation of ZmGA3ox2 when the dose was higher than 0.12 g AI kg-1 seed. With increasing doses of microencapsulated tebuconazole, the transcript levels of ZmGA2ox4, ZmGA2ox5 and ZmGA2ox6 exhibited upward trends, whereas the transcript levels of ZmGA2ox7 exhibited a downward trend.

  9. The Gene pat-2, Which Induces Natural Parthenocarpy, Alters the Gibberellin Content in Unpollinated Tomato Ovaries1

    Science.gov (United States)

    Fos, Mariano; Nuez, Fernando; García-Martínez, José L.

    2000-01-01

    We investigated the role of gibberellins (GAs) in the effect of pat-2, a recessive mutation that induces facultative parthenocarpic fruit development in tomato (Lycopersicon esculentum Mill.) using near-isogenic lines with two different genetic backgrounds. Unpollinated wild-type Madrigal (MA/wt) and Cuarenteno (CU/wt) ovaries degenerated, but GA3 application induced parthenocarpic fruit growth. On the contrary, parthenocarpic growth of MA/pat-2 and CU/pat-2 fruits, which occurs in the absence of pollination and hormone application, was not affected by GA3. Pollinated MA/wt and parthenocarpic MA/pat-2 ovary development was negated by paclobutrazol, and this inhibitory effect was counteracted by GA3. The main GAs of the early-13-hydroxylation pathway (GA1, GA3, GA8, GA19, GA20, GA29, GA44, GA53, and, tentatively, GA81) and two GAs of the non-13-hydroxylation pathway (GA9 and GA34) were identified in MA/wt ovaries by gas chromatography-selected ion monitoring. GAs were quantified in unpollinated ovaries at flower bud, pre-anthesis, and anthesis. In unpollinated MA/pat-2 and CU/pat-2 ovaries, the GA20 content was much higher (up to 160 times higher) and the GA19 content was lower than in the corresponding non-parthenocarpic ovaries. The application of an inhibitor of 2-oxoglutarate-dependent dioxygenases suggested that GA20 is not active per se. The pat-2 mutation may increase GA 20-oxidase activity in unpollinated ovaries, leading to a higher synthesis of GA20, the precursor of an active GA. PMID:10677440

  10. The role of gibberellins in improving the resistance of tebuconazole-coated maize seeds to chilling stress by microencapsulation.

    Science.gov (United States)

    Yang, Lijuan; Yang, Daibin; Yan, Xiaojing; Cui, Li; Wang, Zhenying; Yuan, Huizhu

    2016-11-07

    Chilling stress during germination often causes severe injury. In the present study, maize seed germination and shoot growth under chilling stress were negatively correlated with the dose of tebuconazole in an exponential manner as predicted by the model Y = A + B × e (-x/k) . Microencapsulation was an effective means of eliminating potential phytotoxic risk. The gibberellins (GAs) contents were higher after microencapsulation treatment than after conventional treatment when the dose of tebuconazole was higher than 0.12 g AI (active ingredient) kg -1 seed. Further analysis indicated that microencapsulation can stimulate ent-kaurene oxidase (KO) activity to some extent, whereas GA 3-oxidase (GA3ox) and GA 2-oxidase (GA2ox) activities remained similar to those in the control. Genes encoding GA metabolic enzymes exhibited different expression patterns. Transcript levels of ZmKO1 increased in the microcapsule treatments compared to the control. Even when incorporated into microcapsules, tebuconazole led to the upregulation of ZmGA3ox1 at doses of less than 0.12 g AI kg -1 seed and to the upregulation of ZmGA3ox2 when the dose was higher than 0.12 g AI kg -1 seed. With increasing doses of microencapsulated tebuconazole, the transcript levels of ZmGA2ox4, ZmGA2ox5 and ZmGA2ox6 exhibited upward trends, whereas the transcript levels of ZmGA2ox7 exhibited a downward trend.

  11. Effects of gibberellin mutations on in vitro shoot bud regeneration of ...

    African Journals Online (AJOL)

    hormone in regulating plant growth and development. It is interesting to know the effects of gibberellin and its signalling pathway on plant regeneration. In this report Arabidopsis thaliana landsberg (wild type), ga1-3 (gibberellin biosynthesis deficiency mutant), gai (gibberellin insensitive mutant), penta mutant (lacking GA1, ...

  12. Auxins and gibberellins in embryonic shoots of Scots pine in relation to flower sex differentiation

    Directory of Open Access Journals (Sweden)

    H. Kulikowska

    2015-01-01

    Full Text Available Flower sex differentiation in Scots pine is correlated with endogenous balance of auxins to gibberellins. Male flower primordia initiation is connected with high amounts of gibberellins whereas the initiation of female ones is associated with a high level of auxins and a low content of gibberellins.

  13. Auxins and gibberellins in embryonic shoots of Scots pine in relation to flower sex differentiation

    OpenAIRE

    H. Kulikowska; J. Kopcewicz; Z. Zatorska; T. Szcześniak

    2015-01-01

    Flower sex differentiation in Scots pine is correlated with endogenous balance of auxins to gibberellins. Male flower primordia initiation is connected with high amounts of gibberellins whereas the initiation of female ones is associated with a high level of auxins and a low content of gibberellins.

  14. Vegetative development and production of essential oil of Patchouli under radiation levels and GA3 applicationDesenvolvimento vegetativo e produção de óleo essencial de patchouli, sombreamento e aplicação de GA3

    Directory of Open Access Journals (Sweden)

    Rafaellen Caroline Storck

    2013-10-01

    Full Text Available Pogostemon cablin Benth. has economical importance due to the essential oil which is used in the pharmaceutical and perfume industries. Among the environment factors, the radiation is extremely important for plant development and its limitation can result on decrease of yield. The application of gibberellins promotes the cellular elongation resulting on increase of plant height. Therefore, the radiation level and plant growth regulators can indirectly affect the essential oil production due its accumulation in the biomass. The objective of this work was to evaluate vegetative development and essential oil production of patchouli under shading and after GA3 application. The experimental design was completely randomized in a 2 x 3 factorial arrangement comparing shading levels (0, 54, and 77% with or without GA3 application (200 mg.L-1. The GA3 was applied 30 days after planting. The plants showed a superior height under 77% of shading and with GA3 at 120 days after planting. The leaf number was superior on plants developed under no radiation limitation and after 75 days of GA3 application. The stem number also was significantly superior under no shading and without GA3. The application of the growth regulator at 75 days also promoted great stem number of branches with 54% of shading. However, treatment with GA3 increased essential oil yield and productivity and greater yield in P. Cablin under shading conditions. The growth regulator can be used to compensate the negative effect of lower radiation levels. This is of great interest for patchouli cultivation as the GA3 application allows to increase plant population and, consequently, biomass and essential oil production.Pogostemon cablin Benth. possui importância econômica devido à produção de óleo essencial utilizado pelas indústrias farmacêuticas e de perfumarias. Dentre os fatores ambientais, a radiação é de extrema importância no desenvolvimento das plantas, onde sua limita

  15. Divergence and adaptive evolution of the gibberellin oxidase genes in plants.

    Science.gov (United States)

    Huang, Yuan; Wang, Xi; Ge, Song; Rao, Guang-Yuan

    2015-09-29

    The important phytohormone gibberellins (GAs) play key roles in various developmental processes. GA oxidases (GAoxs) are critical enzymes in GA synthesis pathway, but their classification, evolutionary history and the forces driving the evolution of plant GAox genes remain poorly understood. This study provides the first large-scale evolutionary analysis of GAox genes in plants by using an extensive whole-genome dataset of 41 species, representing green algae, bryophytes, pteridophyte, and seed plants. We defined eight subfamilies under the GAox family, namely C19-GA2ox, C20-GA2ox, GA20ox,GA3ox, GAox-A, GAox-B, GAox-C and GAox-D. Of these, subfamilies GAox-A, GAox-B, GAox-C and GAox-D are described for the first time. On the basis of phylogenetic analyses and characteristic motifs of GAox genes, we demonstrated a rapid expansion and functional divergence of the GAox genes during the diversification of land plants. We also detected the subfamily-specific motifs and potential sites of some GAox genes, which might have evolved under positive selection. GAox genes originated very early-before the divergence of bryophytes and the vascular plants and the diversification of GAox genes is associated with the functional divergence and could be driven by positive selection. Our study not only provides information on the classification of GAox genes, but also facilitates the further functional characterization and analysis of GA oxidases.

  16. Identification of anther-specific/predominant genes regulated by gibberellin during development of lily anthers.

    Science.gov (United States)

    Hsu, Yi-Feng; Tzeng, Jhih-Deng; Liu, Ming-Che; Yei, Fung-Ling; Chung, Mei-Chu; Wang, Co-Shine

    2008-01-01

    We successfully identify anther-specific/predominant genes induced by gibberellin (GA) at the microspore stage of lily (Lilium longiflorum) anthers. We used a suppression-subtractive hybridization strategy to identify 22 individual cDNAs followed by a reverse RNA dot plot to determine their specificities at the microspore stage. Of the 22 genes, 12 are clearly anther-specific and three are anther-predominant. Sequence analysis revealed that five anther-specific/predominant genes are novel. The transcripts of anther-specific/predominant genes were differentially detected at the microspore development phase; some began accumulating in level as early as the occurrence of meiosis. When uniconazole, an inhibitor of GA biosynthesis was applied in young lily plants we found that all of the anther-specific/predominant genes, with the exception of LLA-139, were up-regulated by GAs in the anther while only some were responsive to the exogenous addition of 100 microM GA3. In situ hybridization with antisense riboprobes of selected genes in the anther showed a strong signal localized to the tapetal layer. The different actions of GA on gene expression in anthers are discussed.

  17. Gibberellins and gravitropism in maize shoots: endogenous gibberellin-like substances and movement and metabolism of [3]gibberellin A

    International Nuclear Information System (INIS)

    Rood, S.B.; Kaufman, P.B.; Abe, H.; Pharis, R.P.

    1987-01-01

    [ 3 H]Gibberellin A 20 (GA 20 ) of high specific radioactivity was applied equilaterally in a ring of microdrops to the internodal pulvinus of shoots of 3-week-old vertical normal maize (Zea mays L.), and to a pleiogravitropic (prostrate) maize mutant, lazy (la). All plants converted the [ 3 H]GA 1 - and [ 3 H]GA 29 -like metabolites as well as to several metabolites with the partitioning and chromatographic behavior of glucosyl conjugates of [ 3 H]GA 1 [ 3 H]GA 29 , and [ 3 H]GA 8 . The tentative identification of these putative [ 3 H]GA glucosyl conjugates was further supported by the release of the free [ 3 H]GA moiety after cleavage with cellulase. Within 12 hours of the [ 3 H]GA 20 feed, there was a significantly higher proportion of total radioactivity in lower than in upper halves of internode and leaf sheaf pulvini in gravistimulated normal maize. Further, there was a significantly higher proportion of putative free GA metabolites of [ 3 H]GA 20 , especially [ 3 H] GA 1 , in the lower halves of normal maize relative to upper halves. The differential localization of the metabolites between upper and lower halves was not apparent in the pleiogravitropic mutant, la. Endogenous GA-like substances were also examined in gravistimulated maize shoots. Forty-eight hours after gravistimulation of 3-week-old maize seedlings, endogenous free GA-like substances in upper and lower leaf sheath and internode pulvini halves were extracted, chromatographed, and bioassayed using the Tanginbozu dwarf rice microdroassay. Lower halves contained higher total levels of GA-like activity

  18. Endophytic fungi: resource for gibberellins and crop abiotic stress resistance.

    Science.gov (United States)

    Khan, Abdul Latif; Hussain, Javid; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung

    2015-03-01

    The beneficial effects of endophytes on plant growth are important for agricultural ecosystems because they reduce the need for fertilizers and decrease soil and water pollution while compensating for environmental perturbations. Endophytic fungi are a novel source of bioactive secondary metabolites; moreover, recently they have been found to produce physiologically active gibberellins as well. The symbiosis of gibberellins producing endophytic fungi with crops can be a promising strategy to overcome the adverse effects of abiotic stresses. The association of such endophytes has not only increased plant biomass but also ameliorated plant-growth during extreme environmental conditions. Endophytic fungi represent a trove of unexplored biodiversity and a frequently overlooked component of crop ecology. The present review describes the role of gibberellins producing endophytic fungi, suggests putative mechanisms involved in plant endophyte stress interactions and discusses future prospects in this field.

  19. Different Responses of an Invasive Clonal Plant Wedelia trilobata and its Native Congener to Gibberellin: Implications for Biological Invasion.

    Science.gov (United States)

    Dai, Zhi-Cong; Fu, Wei; Qi, Shan-Shan; Zhai, De-Li; Chen, Si-Chong; Wan, Ling-Yun; Huang, Ping; Du, Dao-Lin

    2016-02-01

    The invasive clonal plant Wedelia trilobata contains higher levels of ent-kaurane diterpenes, which are precursors of gibberellins (GAs), and higher rates of clonal growth than its native congener W. chinensis in invaded habitats. We hypothesized that the higher levels of endogenous GAs facilitate greater ramet growth in W. trilobata compared with W. chinensis. We quantified endogenous levels of GA1+3 in the two species and compared their growth responses to the changes of endogenous and exogenous GA3 by using short-term and long-term hydroponics experiments. After a period of homogeneous cultivation, levels of endogenous GA1+3 were higher in W. trilobata than in W. chinensis. The reduction of endogenous GAs repressed the emergence of adventitious roots and the growth of W. trilobata in the initial cultivation stage, and inhibited its shoot elongation and biomass. Levels of endogenous GA1+3 were positively correlated with the length of shoots and adventitious roots of W. trilobata. Adventitious roots of W. trilobata also emerged earlier and grew faster when treated with exogenous GA3. In contrast, exogenous GA3 treatment inhibited the length of adventitious roots in W. chinensis, and levels of endogenous GA1+3 did not correlate with shoot or adventitious root length. Our study suggests that GAs accelerate the rapid clonal growth of W. trilobata, more than that of its native congener W. chinensis, illustrating the relationship between plant hormones and the clonal growth of invasive plants. These findings are important for understanding the mechanisms associated with the invasiveness of clonal plants and their potential management.

  20. Increased Nicotiana tabacum fitness through positive regulation of carotenoid, gibberellin and chlorophyll pathways promoted by Daucus carota lycopene β-cyclase (Dclcyb1) expression.

    Science.gov (United States)

    Moreno, J C; Cerda, A; Simpson, K; Lopez-Diaz, I; Carrera, E; Handford, M; Stange, C

    2016-04-01

    Carotenoids, chlorophylls and gibberellins are derived from the common precursor geranylgeranyl diphosphate (GGPP). One of the enzymes in carotenoid biosynthesis is lycopene β-cyclase (LCYB) that catalyzes the conversion of lycopene into β-carotene. In carrot, Dclcyb1 is essential for carotenoid synthesis in the whole plant. Here we show that when expressed in tobacco, increments in total carotenoids, β-carotene and chlorophyll levels occur. Furthermore, photosynthetic efficiency is enhanced in transgenic lines. Interestingly, and contrary to previous observations where overexpression of a carotenogenic gene resulted in the inhibition of the synthesis of gibberellins, we found raised levels of active GA4 and the concommitant increases in plant height, leaf size and whole plant biomass, as well as an early flowering phenotype. Moreover, a significant increase in the expression of the key carotenogenic genes, Ntpsy1, Ntpsy2 and Ntlcyb, as well as those involved in the synthesis of chlorophyll (Ntchl), gibberellin (Ntga20ox, Ntcps and Ntks) and isoprenoid precursors (Ntdxs2 and Ntggpps) was observed. These results indicate that the expression of Dclcyb1 induces a positive feedback affecting the expression of isoprenoid gene precursors and genes involved in carotenoid, gibberellin and chlorophyll pathways leading to an enhancement in fitness measured as biomass, photosynthetic efficiency and carotenoid/chlorophyll composition. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  1. Gibberellins – terpenoid plant hormones: Biological importance and chemical analysis

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Terezie; Tarkowská, Danuše; Strnad, Miroslav; Hedden, P.

    2011-01-01

    Roč. 76, č. 12 (2011), s. 1669-1686 ISSN 0010-0765 R&D Projects: GA AV ČR KAN200380801; GA MŠk ED0007/01/01 Keywords : Gibberellins * Biosynthesis * Signaling * Profiling * Extraction * Purification * Mass spectrometry * Liquid chromatography Subject RIV: EF - Botanics Impact factor: 1.283, year: 2011

  2. Interplay between cytochrome c and gibberellins during Arabidopsis vegetative development

    Czech Academy of Sciences Publication Activity Database

    Racca, S.; Welchen, E.; Gras, D. E.; Tarkowská, Danuše; Turečková, Veronika; Maurino, V. G.; Gonzalez, D. H.

    2018-01-01

    Roč. 94, č. 1 (2018), s. 105-121 ISSN 0960-7412 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Arabidopsis thaliana * cytochrome c * DELLA protein * gibberellin * mitochondrion Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 5.901, year: 2016

  3. Growth, yield and quality responses to gibberellic acid (GA3)of Wax ...

    African Journals Online (AJOL)

    Administrator

    2011-09-26

    Sep 26, 2011 ... quality of jambu madu fruits under field conditions. Key words: Gibberellin, growth, quality, wax apple, yield. INTRODUCTION. The wax apple or jambu var. jambu air madu is a tropical .... according to Miller and Rice-Evans (1997). Total anthocyanin contents of the hydrophilic extracts were measured by the ...

  4. Effects of cold stratification and GA 3 on germination of Arbutus ...

    African Journals Online (AJOL)

    Materials and Methods: The effects of gibberellic acid (GA3) and cold stratification (CS) on seed germination performance were investigated in A. unedo seeds collected from three provenances in the Northern part of Greece. Seeds of each provenance were soaked in solutions of GA3 (500, 1000 or 2000 ppm) for 24 h and ...

  5. GA 3 improves flower yield in some cucurbits treated with lead and ...

    African Journals Online (AJOL)

    Present study reveals florigenic effects of growth hormones (i.e. gibberellic acid, GA3) and heavy metals (i.e., Pb(NO3)2 and HgCl2) in Cucumis sativus L. and Momordica charantia L. Applied GA3 at 400 ppm caused precocious flowering, increasing the number of pistillate and staminate flowers in both plants. Application of ...

  6. Effect of GA3 treatment on seed development and seed-related gene expression in grape.

    Directory of Open Access Journals (Sweden)

    Chenxia Cheng

    Full Text Available The phytohormone gibberellic acid (GA3 is widely used in the table grape industry to induce seedlessness in seeded varieties. However, there is a paucity of information concerning the mechanisms by which GAs induce seedlessness in grapes.In an effort to systematically analyze the cause of this GA3-induced seed abortion, we conducted an in depth characterization of two seeded grape cultivars ('Kyoho' and 'Red Globe', along with a seedless cultivar ('Thompson Seedless', following treatment with GA3. In a similar fashion to the seedless control, which exhibited GA3-induced abortion of the seeds 9 days after full bloom (DAF, both 'Kyoho' and 'Red Globe' seeded varieties exhibited complete abortion of the seeds 15 DAF when treated with GA3. Morphological analyses indicated that while fertilization appeared to occur normally following GA3 treatment, as well as in the untreated seedless control cultivar, seed growth eventually ceased. In addition, we found that GA3 application had an effect on redox homeostasis, which could potentially cause cell damage and subsequent seed abortion. Furthermore, we carried out an analysis of antioxidant enzyme activities, as well as transcript levels from various genes believed to be involved in seed development, and found several differences between GA3-treated and untreated controls.Therefore, it seems that the mechanisms driving GA3-induced seedlessness are similar in both seeded and seedless cultivars, and that the observed abortion of seeds may result at least in part from a GA3-induced increase in cell damage caused by reactive oxygen species, a decrease in antioxidant enzymatic activities, and an alteration of the expression of genes related to seed development.

  7. Oxygen interstitials and vacancies in LaSrGa3O7-based melilites

    Science.gov (United States)

    Xu, Jungu; Li, Xiaohui; Lu, Fengqi; Fu, Hui; Brown, Craig M.; Kuang, Xiaojun

    2015-10-01

    The Sr-rich composition of the layered tetrahedral meililite, La0.8Sr1.2Ga3O6.9, was synthesized and a structural investigation on La0.8Sr1.2Ga3O6.9 using neutron powder diffraction revealed a site preference of oxygen vacancies on the bridging oxygen sites of the 4-linked GaO4 tetrahedra. Impedance measurement revealed limited ionic conduction in the oxygen-deficient La0.8Sr1.2Ga3O6.9, presumably associated with oxygen vacancies, which is ~2 orders of magnitude higher than the parent material LaSrGa3O7 but ~3-4 orders of magnitude lower than the interstitial oxide ionic conductivity in La-rich composition, La1.54Sr0.46Ga3O7.27. Low temperature neutron powder diffraction characterization was performed for the oxygen-excess, La-rich composition, La1.54Sr0.46Ga3O7.27, which confirmed the position near the center of the pentagonal tunnels for the oxygen interstitials identified previously using the room temperature data. Solid state 71Ga NMR data collected on these LaSrGa3O7-based materials with stoichometric, excess, and deficient oxygen contents was found not able to distinguish these three compositions. A metastability temperature gap within 850-1280 °C was identified for the oxygen interstitial-conducting La1.54Sr0.46Ga3O7.27. The structures of these oxygen excess and deficient gallate melilites further demonstrate the structural flexibility of the LaSrGa3O7-based layer tetrahedral network.

  8. Inhibition of growth of microcultured Hancornia speciosa shoots by 3beta-hydroxylated gibberellins and one of their C-3 deoxy precursors.

    Science.gov (United States)

    Pereira-Netto, A B; McCown, B H; Pharis, R P

    2003-01-01

    Gibberellins (GAs) A(1), A(3), A(4) and A(7), all 3beta-hydroxylated, growth-active GAs, significantly inhibited shoot elongation and the formation of nodes in in vitro-grown Hancornia speciosa, as did GA(20), a 3-deoxy precursor of GA(1). Ancymidol, an early-stage inhibitor of GA biosynthesis, significantly retarded shoot elongation without affecting the formation of nodes. Co-application of ancymidol and GA(1 )did not overcome the ancymidol-induced growth retardation. Trinexapac-ethyl, which can inhibit 3beta-hydroxylation (GA activation) and 2beta-hydroxylation (GA inactivation), gave no significant response on either shoot elongation or node formation, while two isomers of 16,17-dihydro GA(5), also inhibitors of GA 3beta-hydroxylation, significantly inhibited both shoot growth and the formation of nodes. These unusual results may indicate a unique metabolism for GAs in microcultured shoots of H. speciosa.

  9. Expression of NAC1 up-stream regulatory region and its relationship to the lateral root initiation induced by gibberellins and auxins.

    Science.gov (United States)

    Wang, Youhua; Duan, Liusheng; Lu, Mengzhu; Li, Zhaohu; Wang, Minjie; Zhai, Zhixi

    2006-10-01

    A 1050 bp up-stream regulatory fragment of the transcription factor gene NAC1 in Arabidopsis thaliana was isolated using polymerase chain reaction (PCR) based techniques. The fragment was used to substitute the 35S promoter of the pBI121 plasmid to construct a beta-glucuronidase gene (GUS) expression system. The construct was introduced into tobacco (Nicotiana tabaccum) plants by the Agrobacterium-mediated transferring method. GUS expression pattern was studied by using the transgenic lines. The results showed that the GUS driven by the NAC1 up-stream regulatory region was specifically expressed in the root meristem region, basal areas of the lateral root primordium and the lateral roots. The GUS expression was induced by 3-indolebutyric acid (IBA) and gibberellins (GA3 and GA4+7). The results indicated that the up-stream regulatory fragment of NAC1 responded to plant hormones. The fragment might be involved in both auxins and gibberellins signaling in promoting the development of lateral roots.

  10. CvADH1, a member of short-chain alcohol dehydrogenase family, is inducible by gibberellin and sucrose in developing watermelon seeds.

    Science.gov (United States)

    Kim, Joonyul; Kang, Hong-Gyu; Jun, Sung-Hoon; Lee, Jinwon; Yim, Jieun; An, Gynheung

    2003-01-01

    To understand the molecular mechanisms that control seed formation, we selected a seed-preferential gene (CvADH1) from the ESTs of developing watermelon seeds. RNA blot analysis and in situ localization showed that CvADH1 was preferentially expressed in the nucellar tissue. The CvADH1 protein shared about 50% homology with short-chain alcohol dehydrogenase including ABA2 in Arabidopsis thaliana, stem secoisolariciresinol dehydrogenase in Forsythia intermedia, and 3beta-hydroxysterol dehydrogenase in Digitalis lanata. We investigated gene-expression levels in seeds from both normally pollinated fruits and those made parthenocarpic via N-(2-chloro-4-pyridyl)-N'-phenylurea treatment, the latter of which lack zygotic tissues. Whereas the transcripts of CvADH1 rapidly started to accumulate from about the pre-heart stage in normal seeds, they were not detectable in the parthenocarpic seeds. Treating the parthenogenic fruit with GA(3) strongly induced gene expression, up to the level accumulated in pollinated seeds. These results suggest that the CvADH1 gene is induced in maternal tissues by signals made in the zygotic tissues, and that gibberellin might be one of those signals. We also observed that CvADH1 expression was induced by sucrose in the parthenocarpic seeds. Therefore, we propose that the CvADH1 gene is inducible by gibberellin, and that sucrose plays an important role in the maternal tissues of watermelon during early seed development.

  11. Gibberellin mediates the development of gelatinous fibres in the tension wood of inclined Acacia mangium seedlings.

    Science.gov (United States)

    Nugroho, Widyanto Dwi; Nakaba, Satoshi; Yamagishi, Yusuke; Begum, Shahanara; Marsoem, Sri Nugroho; Ko, Jae-Heung; Jin, Hyun-O; Funada, Ryo

    2013-11-01

    Gibberellin stimulates negative gravitropism and the formation of tension wood in tilted Acacia mangium seedlings, while inhibitors of gibberellin synthesis strongly inhibit the return to vertical growth and suppress the formation of tension wood. To characterize the role of gibberellin in tension wood formation and gravitropism, this study investigated the role of gibberellin in the development of gelatinous fibres and in the changes in anatomical characteristics of woody elements in Acacia mangium seedlings exposed to a gravitational stimulus. Gibberellin, paclobutrazol and uniconazole-P were applied to the soil in which seedlings were growing, using distilled water as the control. Three days after the start of treatment, seedlings were inclined at 45 ° to the vertical and samples were harvested 2 months later. The effects of the treatments on wood fibres, vessel elements and ray parenchyma cells were analysed in tension wood in the upper part of inclined stems and in the opposite wood on the lower side of inclined stems. Application of paclobutrazol or uniconazole-P inhibited the increase in the thickness of gelatinous layers and prevented the elongation of gelatinous fibres in the tension wood of inclined stems. By contrast, gibberellin stimulated the elongation of these fibres. Application of gibberellin and inhibitors of gibberellin biosynthesis had only minor effects on the anatomical characteristics of vessel and ray parenchyma cells. The results suggest that gibberellin is important for the development of gelatinous fibres in the tension wood of A. mangium seedlings and therefore in gravitropism.

  12. Isolation and characterisation of a dwarf rice mutant exhibiting defective gibberellins biosynthesis.

    Science.gov (United States)

    Ji, S H; Gururani, M A; Lee, J W; Ahn, B-O; Chun, S-C

    2014-03-01

    We have isolated a severe dwarf mutant derived from a Ds (Dissociation) insertion mutant rice (Oryza sativa var. japonica c.v. Dongjin). This severe dwarf phenotype, has short and dark green leaves, reduced shoot growth early in the seedling stage, and later severe dwarfism with failure to initiate flowering. When treated with bioactive GA3 , mutants are restored to the normal wild-type phenotype. Reverse transcription PCR analyses of 22 candidate genes related to the gibberellin (GA) biosynthesis pathway revealed that among 22 candidate genes tested, a dwarf mutant transcript was not expressed only in one OsKS2 gene. Genetic analysis revealed that the severe dwarf phenotype was controlled by recessive mutation of a single nuclear gene. The putative OsKS2 gene was a chromosome 4-located ent-kaurene synthase (KS), encoding the enzyme that catalyses an early step of the GA biosynthesis pathway. Sequence analysis revealed that osks2 carried a 1-bp deletion in the ORF region of OsKS2, which led to a loss-of-function mutation. The expression pattern of OsKS2 in wild-type cv Dongjin, showed that it is expressed in all organs, most prominently in the stem and floral organs. Morphological characteristics of the dwarf mutant showed dramatic modifications in internal structure and external morphology. We propose that dwarfism in this mutant is caused by a point mutation in OsKS2, which plays a significant role in growth and development of higher plants. Further investigation on OsKS2 and other OsKS-like proteins is underway and may yield better understanding of the putative role of OsKS in severe dwarf mutants. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Effects of GA3 applications on seedlesness and fruit quality in black myrtle (Myrtus communis L.

    Directory of Open Access Journals (Sweden)

    Esra Alım

    2017-12-01

    Full Text Available Myrtle (Myrtus communis L. is one of the medical and aromatic plants naturally grown in Mediterranean basin. Myrtle fruits are mostly consumed as fresh or dried while essential oils obtained from the leaves are widely used in pharmacy, perfumery, cosmetic and even as pesticide. Myrtle fruits have white and black color. Nowadays, there is a big demand for myrtle fruits because of its high antioxidant capacity. But it contains high amount of seeds which reduce marketing and production. Main objective of this study is to investigate the effects of GA3 on seedlesness and quality in black myrtle fruits. At different flowering stages, GA3 dose of 100 ppm were applied to whole of the plants. Some applications significantly reduced seed number in fruits. Two applications of GA3 at great ballon and full bloom stages consecutively decreased seed number from 10.69 (control to 1.98 seed fruit-1 . In addition, with three consecutive application of GA3, seed rate decreased to 4.98% while 15.08% in control. Some GA3 applications resulted in fully seedless fruits up to 10.67%. Conversely, GA3 applications did not change fruit weight and some biochemical parameters of fruits.

  14. Efek Konsentrasi Hormon Giberelin (Ga3) dan Lama Perendaman pada Berbagai Pembelahan terhadap Perkecambahan Benih Manggis (Garcinia Mangostana L)

    OpenAIRE

    Suhendra, Dede; Nisa, T. Chairun; Sofia Hanafiah, Diana

    2016-01-01

    Purpose of this study is to determine the best number of seeds cuttings, gibberellin concentration and immersion time for the germination of mangosteen seeds. This research conducted at Laboratory of Seed Technology Faculty Agriculture, University of Sumatera Utara, Medan from December to March 2016. Experimental design used a factorial randomized block design with three factors, seed cutting, gibberellin concentrations and immersion time. Parameters measured were membrane leakage (μmhos), no...

  15. Germination induction of dormant Avena fatua caryopses by KAR(1) and GA(3) involving the control of reactive oxygen species (H2O2 and O2(·-)) and enzymatic antioxidants (superoxide dismutase and catalase) both in the embryo and the aleurone layers.

    Science.gov (United States)

    Cembrowska-Lech, Danuta; Koprowski, Marek; Kępczyński, Jan

    2015-03-15

    Avena fatua L. caryopses did not germinate at 20 °C in darkness because they were dormant. However, they were able to germinate in the presence of karrikinolide (KAR1), a key bioactive compound present in smoke, and also in the presence of gibberellin A3 (GA3), a commonly known stimulator of seed germination. The aim of this study was to collect information on a possible relationship between the above regulators and abscisic acid (ABA), reactive oxygen species (ROS) and ROS scavenging antioxidants in the regulation of dormant caryopses germination. KAR1 and GA3 caused complete germination of dormant A. fatua caryopses. Hydrogen peroxide (H2O2), compounds generating the superoxide (O2(·-)), i.e. menadione (MN), methylviologen (MV) and an inhibitor of catalase activity, aminotriazole (AT), induced germination of dormant caryopses. KAR1, GA3, H2O2 and AT decreased ABA content in embryos. Furthermore, KAR1, GA3, H2O2, MN, MV and AT increased α-amylase activity in caryopses. The effect of KAR1 and GA3 on ROS (H2O2, O2(·-)) and activities of the superoxide dismutase (SOD) and catalase (CAT) were determined in caryopses, embryos and aleurone layers. SOD was represented by four isoforms and catalase by one. In situ localization of ROS showed that the effect of KAR1 and GA3 was associated with the localization of hydrogen peroxide mainly on the coleorhiza. However, the superoxide was mainly localized on the surface of the scutellum. Superoxide was also detected in the protruding radicle. Germination induction of dormant caryopses by KAR1 and GA3 was related to an increasing content of H2O2, O2(·-)and activities of SOD and CAT in embryos, thus ROS homeostasis was probably required for the germination of dormant caryopses. The above regulators increased the content of ROS in aleurone layers and decreased the activities of SOD and CAT, probably leading to the programmed cell death. The presented data provide new insights into the germination induction of A. fatua dormant

  16. Transcriptome profiling reveals the regulatory mechanism underlying pollination dependent and parthenocarpic fruit set mainly mediated by auxin and gibberellin.

    Science.gov (United States)

    Tang, Ning; Deng, Wei; Hu, Guojian; Hu, Nan; Li, Zhengguo

    2015-01-01

    Fruit set is a key process for crop production in tomato which occurs after successful pollination and fertilization naturally. However, parthenocarpic fruit development can be uncoupled from fertilization triggered by exogenous auxin or gibberellins (GAs). Global transcriptome knowledge during fruit initiation would help to characterize the molecular mechanisms by which these two hormones regulate pollination-dependent and -independent fruit set. In this work, digital gene expression tag profiling (DGE) technology was applied to compare the transcriptomes from pollinated and 2, 4-D/GA3-treated ovaries. Activation of carbohydrate metabolism, cell division and expansion as well as the down-regulation of MADS-box is a comprehensive regulatory pathway during pollination-dependent and parthenocarpic fruit set. The signaling cascades of auxin and GA are significantly modulated. The feedback regulations of Aux/IAAs and DELLA genes which functioned to fine-tune auxin and GA response respectively play fundamental roles in triggering fruit initiation. In addition, auxin regulates GA synthesis via up-regulation of GA20ox1 and down-regulation of KNOX. Accordingly, the effect of auxin on fruit set is mediated by GA via ARF2 and IAA9 down-regulation, suggesting that both pollination-dependent and parthenocarpic fruit set depend on the crosstalk between auxin and GA. This study characterizes the transcriptomic features of ovary development and more importantly unravels the integral roles of auxin and GA on pollination-dependent and parthenocarpic fruit set.

  17. Transcriptome profiling reveals the regulatory mechanism underlying pollination dependent and parthenocarpic fruit set mainly mediated by auxin and gibberellin.

    Directory of Open Access Journals (Sweden)

    Ning Tang

    Full Text Available Fruit set is a key process for crop production in tomato which occurs after successful pollination and fertilization naturally. However, parthenocarpic fruit development can be uncoupled from fertilization triggered by exogenous auxin or gibberellins (GAs. Global transcriptome knowledge during fruit initiation would help to characterize the molecular mechanisms by which these two hormones regulate pollination-dependent and -independent fruit set.In this work, digital gene expression tag profiling (DGE technology was applied to compare the transcriptomes from pollinated and 2, 4-D/GA3-treated ovaries. Activation of carbohydrate metabolism, cell division and expansion as well as the down-regulation of MADS-box is a comprehensive regulatory pathway during pollination-dependent and parthenocarpic fruit set. The signaling cascades of auxin and GA are significantly modulated. The feedback regulations of Aux/IAAs and DELLA genes which functioned to fine-tune auxin and GA response respectively play fundamental roles in triggering fruit initiation. In addition, auxin regulates GA synthesis via up-regulation of GA20ox1 and down-regulation of KNOX. Accordingly, the effect of auxin on fruit set is mediated by GA via ARF2 and IAA9 down-regulation, suggesting that both pollination-dependent and parthenocarpic fruit set depend on the crosstalk between auxin and GA.This study characterizes the transcriptomic features of ovary development and more importantly unravels the integral roles of auxin and GA on pollination-dependent and parthenocarpic fruit set.

  18. Differential expression of gibberellin- and abscisic acid-related genes implies their roles in the bud activity-dormancy transition of tea plants.

    Science.gov (United States)

    Yue, Chuan; Cao, Hongli; Hao, Xinyuan; Zeng, Jianming; Qian, Wenjun; Guo, Yuqiong; Ye, Naixing; Yang, Yajun; Wang, Xinchao

    2018-03-01

    Thirty genes involved in GA and ABA metabolism and signalling were identified, and the expression profiles indicated that they play crucial roles in the bud activity-dormancy transition in tea plants. Gibberellin (GA) and abscisic acid (ABA) are fundamental phytohormones that extensively regulate plant growth and development, especially bud dormancy and sprouting transition in perennial plants. However, there is little information on GA- and ABA-related genes and their expression profiles during the activity-dormancy transition in tea plants. In the present study, 30 genes involved in the metabolism and signalling pathways of GA and ABA were first identified, and their expression patterns in different tissues were assessed. Further evaluation of the expression patterns of selected genes in response to GA 3 and ABA application showed that CsGA3ox, CsGA20ox, CsGA2ox, CsZEP and CsNCED transcripts were differentially expressed after exogenous treatment. The expression profiles of the studied genes during winter dormancy and spring sprouting were investigated, and somewhat diverse expression patterns were found for GA- and ABA-related genes. This diversity was associated with the bud activity-dormancy cycle of tea plants. These results indicate that the genes involved in the metabolism and signalling of GA and ABA are important for regulating the bud activity-dormancy transition in tea plants.

  19. Gibberellin biosynthesis in cell-free extracts from developing Cucurbita maxima embryos and the identification of new endogenous gibberellins.

    Science.gov (United States)

    Lange, T; Hedden, P; Graebe, J E

    1993-03-01

    Gibberellin (GA) biosynthetic pathways from GA12-aldehyde, GA12 and GA53 were investigated in cell-free systems from developing embryos of Cucurbita maxima L. Gibberellin A12-aldehyde and GA12 were converted to GA25, putative 12α-hydroxyGA25, GA13 and GA39 as main products. Minor products were GA4, GA34 and, when GA12 was the substrate, putative 12α-hydroxyGA12. The intermediates GA15 and GA24 accumulated at low protein concentrations. The influence of various factors on GA12 metabolism was examined. At low 2-oxoglutarate and ascorbate concentrations, or at acid pH, 3β-hydroxylated products predominated, whereas with increasing 2-oxoglutarate and ascorbate concentrations, or at neutral pH, the yield of 12α-hydroxylated GAs increased. Gibberellin A53 was metabolised mainly to the C20-GAs GA44, GA19, GA17, GA23 and GA28, with the C19-GAs GA20, GA1 and GA8 as minor products. Only C19-GAs were 2β-hydroxylated, which is a main characteristic of the embryo systems. In addition to GA13, GA25, GA39, GA43, GA49, GA58, GA74, 12α-hydroxyGA25 and GA39 3-isovalerate, which were known previously from embryos of C. maxima, GA1, GA4, GA17, GA28, GA37, GA38, GA48, GA85, 12α-hydroxyGA37 and putative 12α-hydroxyGA43 were identified as endogenous components by full-scan capillary gas chromatography-mass spectrometry and Kovats retention indices. Evidence for putative 2β-hydroxyGA28 and GA23 was also obtained but it was less conclusive because of contamination.

  20. Effects of auxin transport inhibitors on gibberellins in pea

    International Nuclear Information System (INIS)

    Ross, J.J.

    1998-01-01

    The effects of the auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA), 9-hydroxyfluorene-9-carboxylic acid (HFCA), and 1-N-naphthylphthalamic acid (NPA) on gibberellins (GAs) in the garden pea (Pisum sativum L.) were studied. Application of these compounds to elongating internodes of intact wild type plants reduced markedly the endogenous level of the bioactive gibberellin A1. (GA1) below the application site. Indole-3-acetic acid (IAA) levels were also reduced, as was internode elongation. The auxin transport inhibitors did not affect the level of endogenous GA1 above the application site markedly, nor that of GA1 precursors above or below it. When plants were treated with [13C,3H]GA20, TIBA reduced dramatically the level of [13C,3H]GA1 recovered below the TIBA application site. The internodes treated with auxin transport inhibitors appeared to be still in the phase where endogenous GA1 affects elongation, as indicated by the strong response to applied GA1 by internodes of a GA1-deficient line at the same stage of expansion. On the basis of the present results it is suggested that caution be exercised when attributing the developmental effects of auxin transport inhibitors to changes in IAA level alone

  1. QTL mapping for microtuber dormancy and GA3content in a diploid potato population.

    Science.gov (United States)

    Naz, Raja Mohib Muazzam; Li, Mengtai; Ramzan, Safia; Li, Gege; Liu, Jun; Cai, Xingkui; Xie, Conghua

    2018-01-23

    The genetic control of dormancy is poorly understood in most plant species, but dormancy is a prominent feature for the potato industry. We used the microtuber system, in which tubers were produced in vitro and stored at 20°C, to perform quantitative trait locus (QTL) analysis for dormancy and gibberellic acid (GA 3 ) content in an F 1 population consisting of 178 genotypes derived from an interspecific cross between Solanum chacoense acc. PI 320285 (long dormancy) and Solanum phureja acc. DM1-3 516 R44 (short dormancy). In this analysis, 163 markers were used to construct a genetic map with a total length of 591.8 cM. Through QTL analysis, we identified 22 markers closely linked to the timing of dormancy release and GA 3 content. The male parent alleles were closely related with long dormancy, with the most significant effect on chromosome I, which accounted for 9.4% of phenotypic variation. The dormancy and GA 3 QTLs localized to the same position in the genome, confirming that same genomic region controls GA 3 content at different developmental stages or in dormant and sprouting tubers. The identified QTLs may be useful for future breeding strategies and studies of dormancy in potato. © 2018. Published by The Company of Biologists Ltd.

  2. Growth, yield and quality responses to gibberellic acid (GA 3 ) of ...

    African Journals Online (AJOL)

    A study was carried out to investigate the effects of gibberellic acid (GA3) on the growth and development of the red jambu air madu fruits (Syzygium samarangense). Various horticultural parameters were monitored during two seasons of fruit growth between December, 2008 to December, 2009 with the application of three ...

  3. Effect of Thiamine, Ascorbic acid and Gibberellic acid (GA3 on Growth Characteristics, Pigment Content and Reduced Sugars of Petunia

    Directory of Open Access Journals (Sweden)

    moslem salehi

    2017-02-01

    analyzed using statistical package SAS and means were compared using LSD test at the level of statistical significance of P˂0.05. Results and Discussion: The results indicated that GA3 affected all the measured characteristics except carotenoids in comparison with thiamine and ascorbic acid. Meanwhile, the combined application of GA3 and ascorbic acid affected stem growth, root growth and flower diameter. Simultaneous use of GA3 and thiamine was effective on pigments, reducing sugar, carotenoids and flower number. The simultaneous application of three chemicals resulted in a considerable increase in growth and development traits, such as stem and root growth, flower number and diameter, pigments and reducing sugar compared to control. Generally, gibberellic acid will increase vegetative growth with impress cellular processes, including stimulation cell division and cell elongation. It was reported that the uses of ascorbic acid and gibberellic acid in Thyme (Thymus vulgaris increased plant height and root length. Ascorbic acid makes a set of functions such as cell division and enlargements, cell wall development and other developmental processes in plants. Ascorbic acid affects plasma membrane proton pump and according to the acidic theory stimulates weaking cell wall and consequently will increase cell wall development and cell enlargement. It was found that thiamine significantly increased flower number in chrysanthemum . Conclusion: The results indicated that the synergistic effects of this material can be used to enhance the growth and development of petunia. On the other hand, in arid and semiarid areas of the country, that drought and salinity stresses somewhat inevitable, these materials, especially vitamins are effective in reducing stress and increase flowering period.

  4. Molecular biology of gibberellins signaling in higher plants.

    Science.gov (United States)

    Itoh, Hironori; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto

    2008-01-01

    Gibberellins (GAs), a large family of tetracyclic, diterpenoid plant hormones, play an important role in regulating diverse processes throughout plant development. In recent years, significant advances have been made in the isolation of GA signaling components and GA-responsive genes. All available data have indicated that DELLA proteins are an essential negative regulator in the GA signaling pathway and GA derepresses DELLA-mediated growth suppression by inducing degradation of DELLA proteins through the ubiquitin-26S proteasome proteolytic pathway. Identification of GID1, a gene encoding an unknown protein with similarity to hormone-sensitive lipases, has revealed that GID1 acts as a functional GA receptor with a reasonable binding affinity to biologically active GAs. Furthermore, the GID1 receptor interacts with DELLA proteins in a GA-dependent manner. These results suggest that formation of a GID1-GA-DELLA protein complex targets DELLA protein into the ubiquitin-26S proteasome pathway for degradation.

  5. Genetics of dwarfness in induced mutants of hexaploid triticale and its response to exogenous GA3

    International Nuclear Information System (INIS)

    Reddy, V.D.; Reddy, G.M.

    1991-01-01

    Genetics of dwarfism in two induced mutant (d 1 and d 2 ) of hexaploid triticale, DTS 330, revealed that this trait is governed by single recessive gene. Both d 1 and d 2 were allelic to each other and d 1 was dominant over d 2 . Both d 1 , d 2 and their F 1 showed no response to exogenous GA 3 , whereas, DTS 330, d 1 x DTS 330 and d 2 x DTS 330 were responsive. The endogenous levels of GA 3 were more in the dwarf mutants than control, suggesting that dwarfness in these may be due to a partial block in the GA utilizing mechanism, rather than a block in GA biosynthesis. (author). 5 refs., 2 tabs

  6. Gibberellin overproduction promotes sucrose synthase expression and secondary cell wall deposition in cotton fibers.

    Directory of Open Access Journals (Sweden)

    Wen-Qin Bai

    Full Text Available Bioactive gibberellins (GAs comprise an important class of natural plant growth regulators and play essential roles in cotton fiber development. To date, the molecular base of GAs' functions in fiber development is largely unclear. To address this question, the endogenous bioactive GA levels in cotton developing fibers were elevated by specifically up-regulating GA 20-oxidase and suppressing GA 2-oxidase via transgenic methods. Higher GA levels in transgenic cotton fibers significantly increased micronaire values, 1000-fiber weight, cell wall thickness and cellulose contents of mature fibers. Quantitative RT-PCR and biochemical analysis revealed that the transcription of sucrose synthase gene GhSusA1 and sucrose synthase activities were significantly enhanced in GA overproducing transgenic fibers, compared to the wild-type cotton. In addition, exogenous application of bioactive GA could promote GhSusA1 expression in cultured fibers, as well as in cotton hypocotyls. Our results suggested that bioactive GAs promoted secondary cell wall deposition in cotton fibers by enhancing sucrose synthase expression.

  7. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions

    Science.gov (United States)

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-01-01

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis. PMID:26902640

  8. An intense charge transfer broadband sensitized near-infrared emitting CaLaGa3S3O:Yb3+ phosphor suitable for solar spectral convertor.

    Science.gov (United States)

    Zhang, Gongguo; Liu, Chunmeng; Wang, Jing; Kuang, Xiaojun; Su, Qiang

    2011-11-21

    A near-infrared (NIR) phosphor, CaLaGa(3)S(6)O:Yb(3+), is developed as a promising solar spectral convertor for Si solar cells. The structure, photoluminescence excitation and emission spectra, concentration effect are investigated. The results show that CaLaGa(3)S(6)O:Yb(3+) has an efficient broad absorption band dominating around the 345 nm ascribing to the charge transfer state (CTS) of Yb(3+)-S(2-) and exhibits an intense NIR emission of Yb(3+) between 920 and 1150 nm, perfectly matching the maximum spectral response of Si solar cells. The NIR emission intensity of CaLaGa(3)S(6)O:Yb(3+) is 12 times as intense as that of a NIR quantum cutting phosphor Ca(2)BO(3)Cl:Ce(3+), Tb(3+), Yb(3+) (CBC) upon 4f-5d excitation of Ce(3+). These results demonstrate that the allowed CTS of Yb(3+)-S(2-) with high absorption cross-section can be an efficient and direct sensitizer harvesting UV-blue photons and greatly enhancing the NIR emission of Yb(3+) ion. © 2011 Optical Society of America

  9. Infrared and Raman scattering spectra of layered structured Ga3InSe4 crystals

    Science.gov (United States)

    Isik, M.; Gasanly, N. M.; Korkmaz, F.

    2013-03-01

    The infrared reflectivity and transmittance and Raman scattering in Ga3InSe4 layered crystals were investigated in the frequency ranges of 100-400, 400-4000 and 25-500 cm-1. The refractive and absorption indices, the frequencies of transverse and longitudinal optical modes, high- and low-frequency dielectric constants were obtained from the analysis of the IR reflectivity spectra. The bands observed in IR transmittance spectra were interpreted in terms of two-phonon absorption processes.

  10. Growth of a mangrove (Rhizophora apiculata seedlings as influenced by GA3 , light and salinity

    Directory of Open Access Journals (Sweden)

    K Kathiresan

    2002-06-01

    Full Text Available The growth performance of Rhizophora apiculata Blume (mangrove seedlings in the presence and absence of exogenous gibberellic acid (GA3 under different combinations of salinity and light was analyzed. Root and shoot growth responses of 75-day old seedlings in liquid-culture, were measured. It was concluded that light exhibited a significant inhibitory effect on all the growth parameters-number of primary roots, primary root length, shoot elongation, number of leaves, total leaf area; and, the GA3 treatment singly or in combinations with light, showed a significant influence on the total leaf area and primary root lengthSe analizó el crecimiento de las semillas de mangle Rhizophora apiculata Blume en presencia y ausencia de ácido giberelico (GA3 exógeno bajo diferentes combinaciones de salinidad y luz. Se midió crecimiento de la raíz y el brote en plántulas de 75 días de germinación en medio de cultivo líquido. Se concluye que la luz presenta un efecto inhibitorio significativo respecto a todos los parámetros de crecimiento - número de raíces primarias, longitud de la raíz primaria, elongación de la plántula, número de hojas, área total de las hojas; y el tratamiento de GA3 solo o en combinaciones con luz, mostró una influencia significativa sobre el área total de las hojas y longitud de la raíz primaria

  11. Acides gras oméga 3 et maladies cardiovasculaires : approches épidémiologiques

    Directory of Open Access Journals (Sweden)

    Ducimetiere Pierre

    2004-01-01

    Full Text Available La prise alimentaire d’acides gras oméga 3 a de nombreuses conséquences biologiques en particulier dans les domaines intéressant le risque cardiovasculaire (thrombose, métabolisme lipidique, inflammation. A partir de l’énorme littérature épidémiologique sur le sujet, on peut conclure que la consommation de poisson « gras » ou d’oméga 3 à longue chaîne a un effet protecteur sur la mortalité coronaire et plus généralement sur les maladies cardiovasculaires. Il existe des indications en faveur d’un effet similaire de l’apport en alphalinolénique (ALA. Les essais de prévention secondaire avec des oméga 3 à longue chaîne ont confirmé ces résultats mais les essais de conseils nutritionnels favorisant la consommation d’ALA ne sont qu’indicatifs. Il n’existe guère « d’evidence » en faveur du rôle des oméga sur le développement quantitatif de l’athérome alors que leur effet protecteur sur la vulnérabilité cardiaque aux arythmies est bien établie. Ces données expérimentales et cliniques fournissent une base biologique à la relation observée entre un apport augmenté de poisson ou d’oméga 3 et un risque abaissé de mort subite dans plusieurs études de cohortes.

  12. Influence of GA3 and NAA on certain carbohydrate fractions in corms of saffron crocus (Crocus sativus L. during development

    Directory of Open Access Journals (Sweden)

    Nikhil K. Chrungoo

    2014-01-01

    Full Text Available Application of gibberellic acid (GA3 and napthaleneacetic acid (NAA to corms of saffron crocus (Crocus sativus L. markedly influenced degradation of reserve carbohydrates in the corm tissues. GA3 stimulated the breakdown of starch and promoted the accumulation of soluble sugars, especially sucrose. Although NAA treatment stimulated starch breakdown for the first 14 days after the treatment, the effect was less pronounced as compared to that of GA3. NAA treatment promoted the accumulation of reducing sugars but suppressed accumulation of non reducing sugars in the corm tissues. Corms treated with GA3 showed an increased accumulation of total pentoses and total ketoses. In NAA treated corms, accumulation of total pentoses was stimulated but that of total ketoses was suppressed. The effects of GA3 and NAA on carbohydrate changes in the corm tissues are discussed in the light of their effects on bud development.

  13. Endogenous diterpenes derived from ent-kaurene, a common gibberellin precursor, regulate protonema differentiation of the moss Physcomitrella patens.

    Science.gov (United States)

    Hayashi, Ken-ichiro; Horie, Keisuke; Hiwatashi, Yuji; Kawaide, Hiroshi; Yamaguchi, Shinjiro; Hanada, Atsushi; Nakashima, Tamotsu; Nakajima, Masatoshi; Mander, Lewis N; Yamane, Hisakazu; Hasebe, Mitsuyasu; Nozaki, Hiroshi

    2010-07-01

    Gibberellins (GAs) are a group of diterpene-type plant hormones biosynthesized from ent-kaurene via ent-kaurenoic acid. GAs are ubiquitously present in seed plants. The GA signal is perceived and transduced by the GID1 GA receptor/DELLA repressor pathway. The lycopod Selaginella moellendorffii biosynthesizes GA and has functional GID1-DELLA signaling components. In contrast, no GAs or functionally orthologous GID1-DELLA components have been found in the moss Physcomitrella patens. However, P. patens produces ent-kaurene, a common precursor for GAs, and possesses a functional ent-kaurene synthase, PpCPS/KS. To assess the biological role of ent-kaurene in P. patens, we generated a PpCPS/KS disruption mutant that does not accumulate ent-kaurene. Phenotypic analysis demonstrates that the mutant has a defect in the protonemal differentiation of the chloronemata to caulonemata. Gas chromatography-mass spectrometry analysis shows that P. patens produces ent-kaurenoic acid, an ent-kaurene metabolite in the GA biosynthesis pathway. The phenotypic defect of the disruptant was recovered by the application of ent-kaurene or ent-kaurenoic acid, suggesting that ent-kaurenoic acid, or a downstream metabolite, is involved in protonemal differentiation. Treatment with uniconazole, an inhibitor of ent-kaurene oxidase in GA biosynthesis, mimics the protonemal phenotypes of the PpCPS/KS mutant, which were also restored by ent-kaurenoic acid treatment. Interestingly, the GA(9) methyl ester, a fern antheridiogen, rescued the protonemal defect of the disruption mutant, while GA(3) and GA(4), both of which are active GAs in angiosperms, did not. Our results suggest that the moss P. patens utilizes a diterpene metabolite from ent-kaurene as an endogenous developmental regulator and provide insights into the evolution of GA functions in land plants.

  14. Salinity Inhibits Rice Seed Germination by Reducing α-Amylase Activity via Decreased Bioactive Gibberellin Content

    Directory of Open Access Journals (Sweden)

    Li Liu

    2018-03-01

    Full Text Available Seed germination plays important roles in the establishment of seedlings and their subsequent growth; however, seed germination is inhibited by salinity, and the inhibitory mechanism remains elusive. Our results indicate that NaCl treatment inhibits rice seed germination by decreasing the contents of bioactive gibberellins (GAs, such as GA1 and GA4, and that this inhibition can be rescued by exogenous bioactive GA application. To explore the mechanism of bioactive GA deficiency, the effect of NaCl on GA metabolic gene expression was investigated, revealing that expression of both GA biosynthetic genes and GA-inactivated genes was up-regulated by NaCl treatment. These results suggest that NaCl-induced bioactive GA deficiency is caused by up-regulated expression of GA-inactivated genes, and the up-regulated expression of GA biosynthetic genes might be a consequence of negative feedback regulation of the bioactive GA deficiency. Moreover, we provide evidence that NaCl-induced bioactive GA deficiency inhibits rice seed germination by decreasing α-amylase activity via down-regulation of α-amylase gene expression. Additionally, exogenous bioactive GA rescues NaCl-inhibited seed germination by enhancing α-amylase activity. Thus, NaCl treatment reduces bioactive GA content through promotion of bioactive GA inactivation, which in turn inhibits rice seed germination by decreasing α-amylase activity via down-regulation of α-amylase gene expression.

  15. Interaction of a Brassinosteroid with IAA and GA_3 in the Elongation of Cucumber Hypocotyl Sections

    OpenAIRE

    Masayuki, Katsumi; Biology Department, International Christian University

    1985-01-01

    A synthetic brassinosteroid, 22,23(S,S)-homobrassinolide (hBR), was examined for its interaction with IAA and GA_3 In the elongation of hypocotyl sections of light-grown cucumber (Cucumis sativus L. cv. Aonagajibai) seedlings. hBR alone was less active than IAA. Its optimal concentration was around 10μM and the lowest effective concentration between 10 and 100μM, which is more than 100 times higher than that of brassinolide. hBR was more active in sections from younger seedlings. Its growth-p...

  16. Infrared and Raman scattering spectra of layered structured Ga3InSe4 crystals

    International Nuclear Information System (INIS)

    Isik, M.; Gasanly, N.M.; Korkmaz, F.

    2013-01-01

    The infrared reflectivity and transmittance and Raman scattering in Ga 3 InSe 4 layered crystals were investigated in the frequency ranges of 100–400, 400–4000 and 25–500 cm −1 . The refractive and absorption indices, the frequencies of transverse and longitudinal optical modes, high- and low-frequency dielectric constants were obtained from the analysis of the IR reflectivity spectra. The bands observed in IR transmittance spectra were interpreted in terms of two-phonon absorption processes

  17. Analyses of gibberellins in coconut (Cocos nucifera L.) water by partial filling-micellar electrokinetic chromatography-mass spectrometry with reversal of electroosmotic flow.

    Science.gov (United States)

    Ge, Liya; Yong, Jean Wan Hong; Tan, Swee Ngin; Hua, Lin; Ong, Eng Shi

    2008-05-01

    In this paper, we present the results of simultaneous screening of eight gibberellins (GAs) in coconut (Cocos nucifera L.) water by MEKC directly coupled to ESI-MS detection. During the development of MEKC-MS, partial filling (PF) was used to prevent the micelles from reaching the mass spectrometer as this is detrimental to the MS signal, and a cationic surfactant, cetyltrimethylammonium hydroxide, was added to the electrolyte to reverse the EOF. On the basis of the resolution of the neighboring peaks, different parameters (i.e., the pH and concentration of buffer, surfactant concentrations, length of the injected micellar plug, organic modifier, and applied separation voltage) were optimized to achieve a satisfactory PF-MEKC separation of eight GA standards. Under optimum conditions, a baseline separation of GA standards, including GA1, GA3, GA5, GA6, GA7, GA9, GA12, and GA13, was accomplished within 25 min. Satisfactory results were obtained in terms of precision (RSD of migration time below 0.9%), sensitivity (LODs in the range of 0.8-1.9 microM) and linearity (R2 between 0.981 and 0.997). MS/MS with multiple reaction monitoring (MRM) detection was carried out to obtain sufficient selectivity. PF-MEKC-MS/MS allowed the direct identification and confirmation of the GAs presented in coconut water (CW) sample after SPE, while, the quantitative analysis of GAs was performed by PF-MEKC-MS approach. GA1 and GA3 were successfully detected and quantified in CW. It is anticipated that the current PF-MEKC-MS method can be applicable to analyze GAs in a wide range of biological samples.

  18. Functional analysis of synthetic DELLA domain peptides and bioactive gibberellin assay using surface plasmon resonance technology.

    Science.gov (United States)

    Zhao, Zhuoya; Xing, Zenan; Zhou, Min; Chen, Yi; Li, Chenzhong; Wang, Ruozhong; Xu, Wenzhong; Ma, Mi

    2015-11-01

    DELLA proteins and phytohormone gibberellin act together to control convergence point of plant development. A gibberellin-bound nuclear receptor that interacts with the N-terminal domain of DELLA proteins is required for gibberellin induced degradation of DELLA proteins. N-terminal DELLA domain includes two conserved motifs: DELLA and VHYNP. However, their respective functions remain unclear. Meanwhile, the identification and detection of several bioactive gibberellins from the more than 100 gibberellin metabolites are overwhelmingly difficult for their similar structures. Using in vitro biochemical approach, our work demonstrates for the first time that the synthetic GAI N-terminal DELLA domain peptides have similar bioactive function as the expressed protein to interact with AtGID1a receptor. Furthermore, our results reveal that DELLA motif is vitally important region and DELLA segment is essentially required region to recognize AtGID1a receptor. Finally, based on bioactive GA-dependent of the interaction between AtGID1a and DELLA protein, we generated a new method that could identify and detect bioactive GAs accurately and rapidly with surface plasmon resonance assays. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. GROWTH RETARDANTS: Effects on Gibberellin Biosynthesis and Other Metabolic Pathways.

    Science.gov (United States)

    Rademacher, Wilhelm

    2000-06-01

    Plant growth retardants are applied in agronomic and horticultural crops to reduce unwanted longitudinal shoot growth without lowering plant productivity. Most growth retardants act by inhibiting gibberellin (GA) biosynthesis. To date, four different types of such inhibitors are known: (a) Onium compounds, such as chlormequat chloride, mepiquat chloride, chlorphonium, and AMO-1618, which block the cyclases copalyl-diphosphate synthase and ent-kaurene synthase involved in the early steps of GA metabolism. (b) Compounds with an N-containing heterocycle, e.g. ancymidol, flurprimidol, tetcyclacis, paclobutrazol, uniconazole-P, and inabenfide. These retardants block cytochrome P450-dependent monooxygenases, thereby inhibiting oxidation of ent-kaurene into ent-kaurenoic acid. (c) Structural mimics of 2-oxoglutaric acid, which is the co-substrate of dioxygenases that catalyze late steps of GA formation. Acylcyclohexanediones, e.g. prohexadione-Ca and trinexapac-ethyl and daminozide, block particularly 3ss-hydroxylation, thereby inhibiting the formation of highly active GAs from inactive precursors, and (d) 16,17-Dihydro-GA5 and related structures act most likely by mimicking the GA precursor substrate of the same dioxygenases. Enzymes, similar to the ones involved in GA biosynthesis, are also of importance in the formation of abscisic acid, ethylene, sterols, flavonoids, and other plant constituents. Changes in the levels of these compounds found after treatment with growth retardants can mostly be explained by side activities on such enzymes.

  20. Adventitious staminate flower formation in gibberellin treated gynoecious cucumber plants

    International Nuclear Information System (INIS)

    Fuchs, E.; Atsmon, D.; Halevy, A.H.

    1977-01-01

    Single gibberellin (A sub(4 + 7)) treatments induced the appearance of staminate floral buds in several consecutive nodes on the main stem of genetically female cucumber (Cucumis sativus L.). The staminate buds appeared next to pistillate buds which showed various degrees of degeneration. Similarly, repeated GA treatments induced the appearance of staminate flowers in otherwise strictly hermaphrodite plants, next to bisexual flowers. However, the bisexual buds, unlike the pistillate ones, did not show any deleterious effects of the GA treatment. Therefore, it is inferred that the hormonally induced staminate buds did not develop by sexual reversion of would-be pistillate or bisexual buds, but rather, represent adventitious buds which, in normally grown female or hermaphrodite plants, never develop. It thus seems that predetermined pistillate or bisexual buds do not change into staminate ones, while change in the reverse direction has been demonstrated in the past (at least for the gynoecious ones). The effectiveness of the GA treatment in the gynoecious plants showed an acropetal gradient both within the affected region, as well as along the main stem. Autoradiographic histological examinations showed that the course of development of the induced staminate floral bud did not differ from that of normally developing buds. (auth.)

  1. Thermoinductive regulation of gibberellin metabolism in Thlaspi arvense L

    International Nuclear Information System (INIS)

    Hazebroek, J.P.; Metzger, J.D.

    1990-01-01

    Field pennycress (Thlaspi arvense L.) is a winter annual crucifer with a cold requirement for stem elongation and flowering. In the present study, the metabolism of exogenous [ 2 H]-ent-kaurenoic acid (KA) and [ 14 C]-gibberellin A 12 -aldehyde (GA 12 -aldehyde) was compared in thermo- and noninduced plants. Thermoinduction greatly altered both quantitative and qualitative aspects of [ 2 H]-KA metabolism in the shoot tips. The rate of disappearance of the parent compound was much greater in thermoinduced shoot tips. These results are consistent with the suggestion that the conversion of KA in to GAs is under thermoinductive control only in the shoot tip, the site of perception for thermoinductive temperatures in field pennycress. There were essentially no differences in the qualitative or quantitative distribution of metabolites formed following the application of [ 14 C]GA 12 -aldehyde to the shoot tips of thermo- or noninduced plants. Thus, the apparent thermoinductive regulation of the KA metabolism into GAs is probably limited to the two metabolic steps involved in converting KA to GA 12 -aldehyde

  2. Changes in endogenous gibberellin-like substances in onion bulbs (Allium cepa L. cv. Sochaczewska during storage

    Directory of Open Access Journals (Sweden)

    Elżbieta Kielak

    2013-12-01

    Full Text Available Onions cv. Sochaczewska were dried up under an umbrella roof till October 15th or till November 15th and thereafter stored in a cold room at 0-1°C until May 15th. During 4-year of experiment gibberellin activity was determined each month during storage. Three periods of high activity of gibberellins were found in most cases: in December, in February-March and in late spring. In general, onions dried longer (till November 15th, showed lower gibberellin activity than onions dried shorter. Gibberellin-like substances under investigation are localized in almost all Rf zones of chromatogram. Sprouting and rooting was related to gibberellin activity.

  3. GA3 e Paclobutrazol no florescimento e na produção de frutos em duas cultivares de morangueiro GA3 and Paclobutrazol on the flowering and yield of strawberry

    Directory of Open Access Journals (Sweden)

    Jaime Duarte Filho

    2004-06-01

    Full Text Available Neste trabalho estudou-se o efeito dos fitorreguladores Ga3 e Paclobutrazol no florescimento e produção de frutos de morangueiro (Fragaria x ananassa Duch.. O experimento foi conduzido em Caldas (MG, na EPAMIG. O delineamento experimental adotado foi o de blocos casualizados, com quatro repetições, num esquema fatorial 2x4, onde as variáveis dependentes foram duas cultivares ('Oso Grande' e 'Seascape' e os tratamentos controle (água; GA3 a 40 mg L-1 em duas aplicações (aos 45 e 65 dias após o transplante; paclobutrazol (produto comercial Cultar 10% a 100 mg L-1 aos 75 dias após o transplante das mudas; combinação de GA3 + paclobutrazol aplicados aos 45; 65 e aos 75 dias, respectivamente, após o transplante. Os tratamentos foram aplicados via foliar em ambas as cultivares. A resposta à aplicação dos fitorreguladores GA3 e paclobutrazol em morangueiro depende da cultivar. A cv. Seascape, de dia neutro, respondeu melhor à aplicação de GA3 que a 'Oso Grande', de dia curto; Por outro lado, o paclobutrazol, quando aplicado via foliar, aos 75 dias após o transplante, reduziu o florescimento do morangueiro o que mostra a necessidade de mais pesquisas sobre dosagens e épocas de aplicação do paclobutrazol nesta cultura.The effect of bioregulators GA3 and paclobutrazol was evaluated on flowering and yield of strawberry cultivars Oso Grande and Seascape. The experiment was carried out in Caldas, Minas Gerais State, Brazil. The treatments consisted of control (no application of bioregulators; GA3 at 40 mg L-1, in two applications (45 and 65 days after transplanting date; paclobutrazol (commercial product Cultar, 10% at 100 mg L-1, 75 days after transplanting date; combination of GA3 + paclobutrazol, applied 45; 65 and 75 days, respectively, after transplanting date. The experimental design was a randomized complete block, with four replications, in a factorial 2x4. The response to the bioregulators GA3 and Paclobutrazol was cultivar

  4. Seed-borne endophytic Bacillus amyloliquefaciens RWL-1 produces gibberellins and regulates endogenous phytohormones of Oryza sativa.

    Science.gov (United States)

    Shahzad, Raheem; Waqas, Muhammad; Khan, Abdul Latif; Asaf, Sajjad; Khan, Muhammad Aaqil; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

    2016-09-01

    Some microorganisms are adapted to an endophytic mode, living symbiotically with plants through vertical transmission in seeds. The role of plant growth-promoting endophytes has been well studied, but those of seed-associated endophytic bacteria are less understood. The current study aimed to isolate and identify bacterial endophytes associated with rice (Oryza sativa L. 'Jin so mi') seeds, their potential to produce gibberellins (GAs), and role in improving host-plant physiology. The isolated bacterial endophyte RWL-1 was identified as Bacillus amyloliquefaciens by using 16S rRNA sequencing and phylogenetic analysis. The pure culture of B. amyloliquefaciens RWL-1, supplied with deuterated internal standards, was subjected to gas chromatography and mass spectrometric selected ion monitoring (GC-MS/SIM) for quantification of GAs. Results showed the presence of GAs in various quantities (ng/mL) viz., GA20 (17.88 ± 4.04), GA36 (5.75 ± 2.36), GA24 (5.64 ± 2.46), GA4 (1.02 ± 0.16), GA53 (0.772 ± 0.20), GA9 (0.12 ± 0.09), GA19 (0.093 ± 0.13), GA5 (0.08 ± 0.04), GA12 (0.014 ± 0.34), and GA8 (0.013 ± 0.01). Since endogenous seed GAs are essential for prolonged seed growth and subsequent plant development, we used exogenous GA3 as a positive control and water as a negative control for comparative analysis of the application of B. amyloliquefaciens RWL-1 to rice plants. The growth parameters of rice plants treated with endophytic bacterial cell application was significantly increased compared to the plants treated with exogenous GA3 and water. This was also revealed by the significant up-regulation of endogenous GA1 (17.54 ± 2.40 ng), GA4 (310 ± 5.41 ng), GA7 (192.60 ± 3.32 ng), and GA9 (19.04 ± 2.49 ng) as compared to results of the positive and negative control treatments. Rice plants inoculated with B. amyloliquefaciens RWL-1 exhibited significantly higher endogenous salicylic acid (1615.06 ± 10.81 μg), whereas

  5. Oméga 3 et neurotransmission cérébrale

    Directory of Open Access Journals (Sweden)

    Vancassel Sylvie

    2004-01-01

    Full Text Available Les acides gras polyinsaturés (AGPI sont des constituants structuraux fondamentaux du système nerveux central (SNC dont la teneur conditionne le fonctionnement des cellules neuronales. Ils sont des acteurs de la communication intercellulaire, notamment à travers les processus de neurotransmission. De nombreuses études ont montré chez l’animal que le déficit des membranes cérébrales en oméga 3, et plus particulièrement en acide docosahexaénoïque (22 : 6ω-3 ou DHA induit par une carence alimentaire spécifique en cette famille d’AGPI, s’accompagne de troubles de l’apprentissage. Un support neurochimique a été avancé, impliquant les processus de libération de neurotransmetteurs, notamment les monoamines et l’acétylcholine. Cette relation entre AGPI ω3 et neurotransmission est d’autant plus intéressante qu’elle pourrait être également impliquée chez l’Homme dans l’apparition et\\\\ou la sévérité de certains troubles neuropsychiatriques dans lesquels des dysfonctionnements de la neurotransmission sont constatés (schizophrénie, dépression, hyperactivité chez l’enfant. En effet, de nombreuses études révèlent un déficit du statut corporel en AGPI oméga 3 (20 : 5 et 22 : 6 mais aussi en oméga 6, qui peut être corrigé par voie nutritionnelle, permettant alors de réduire significativement certains des symptômes pathologiques. Dans ce contexte, nous développons au laboratoire des recherches visant à comprendre les mécanismes d’action des oméga 3, et en particulier du DHA, dans les membranes nerveuses et l’incidence sur le fonctionnement de ces cellules.

  6. Photocontrol of gibberellin metabolism in situ in maize

    International Nuclear Information System (INIS)

    Rood, S.B.; Beall, F.D.; Pharis, R.P.

    1986-01-01

    Mature maize seeds were labeled with 10 to 100 pg per seed of [ 3 H] gibberellins (GA) and [ 3 H]GA glucosyl conjugate-like substances by feeding [ 3 H]GA 20 of high specific activity (2.3 Curies per millimole) during seed maturation. The dry seeds, which contained 14% [ 3 H]GA 20 , 7% putative [ 3 H]GA 1 and 78% [ 3 H]GA glucosyl conjugate-like metabolites, were imbibed and germinated in the dark and under incandescent light. In both light and dark the proportion of [ 3 H]GA conjugate-like metabolities declined (relative to that in the mature dry seeds) during imbibition and up to germination at hour 36. This decline was accompanied by increases in the proportions of [ 3 H]GA 20 and putative [ 3 H]GA 1 thereby indicating hydrolysis, which was greater in the dark than in the light. The proportions of [ 3 H]GA conjugate-like substances in light-grown germinants were higher (121 and 141% of dark-grown) at 24 and 48 hour harvests and this statistically significant pattern was sustained up to 120 hours after imbibition. Conversely, the proportions of [ 3 H]GA 20 and putative [ 3 H]GA 1 were lower in the light-grown seedlings. Thus, during imbibition, hydrolysis (de-conjugation) of [ 3 H]GA glucosyl conjugate-like substances apparently occurred, and occurred more rapidly in the dark than in the light. Subsequently, during germination the reformation of [ 3 H]GA conjugate-like substances was less rapid in the dark than in the light

  7. Origin of low temperature deactivation of Ni5Ga3 nanoparticles as catalyst for methanol synthesis

    DEFF Research Database (Denmark)

    Gardini, Diego; Sharafutdinov, Irek; Damsgaard, Christian Danvad

    -Ga alloys as active catalysts for methanol production from syngas mixtures and Ni-Ga nanoparticles supported on highly porous silica have been prepared using an incipient wetness impregnation technique from a solution of nickel and gallium nitrates [2]. Tests conducted in a fixed-bed reactor showed...... silica, on this new support Ni5Ga3 nanoparticles becomes directly exposed to the electron beam (Figure 2) allowing us to obtain high resolution TEM images and perform more accurate electron energy loss spectroscopy (EELS) measurements.......In an effort to find alternative energy sources capable to compete with fossil fuels, methanol synthesis could represent a realistic solution to store “green” hydrogen produced from electrolysis or photo-induced water splitting. Recently, density functional theory (DFT) calculations [1] proposed Ni...

  8. Colonization by the endophyte Piriformospora indica leads to early flowering in Arabidopsis thaliana likely by triggering gibberellin biosynthesis.

    Science.gov (United States)

    Kim, Dongjin; Abdelaziz, Mohamad E; Ntui, Valentine Otang; Guo, Xiujie; Al-Babili, Salim

    2017-09-02

    Piriformospora indica is an endophytic fungus colonizing roots of a wide variety of plants. Previous studies showed that P. indica promotes early flowering and plant growth in the medicinal plant Coleus forskohlii. To determine the impact of P. indica on flowering time in Arabidopsis, we co-cultivated the plants with P. indica under long day condition. P. indica inoculated Arabidopsis plants displayed significant early flowering phenotype. qRT-PCR analysis of colonized plants revealed an up-regulation of flowering regulatory (FLOWERING LOCUS T, LEAFY, and APETALA1) and gibberellin biosynthetic (Gibberellin 20-Oxidase2, Gibberellin 3-Oxidase1 and Gibberellin requiring1) genes, while the flowering-repressing gene FLOWERING LOCUS C was down regulated. Quantification of gibberellins content showed that the colonization with P. indica caused an increase in GA 4 content. Compared to wild-type plants, inoculation of the Arabidopsis ga5 mutant affected in gibberellin biosynthetic gene led to less pronounced changes in the expression of genes regulating flowering and to a lower increase in GA 4 content. Taken together, our data indicate that P. indica promotes early flowering in Arabidopsis likely by increasing gibberellin content. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Colonization by the endophyte Piriformospora indica leads to early flowering in Arabidopsis thaliana likely by triggering gibberellin biosynthesis

    KAUST Repository

    Kim, Dongjin

    2017-06-28

    Piriformospora indica is an endophytic fungus colonizing roots of a wide variety of plants. Previous studies showed that P. indica promotes early flowering and plant growth in the medicinal plant Coleus forskohlii. To determine the impact of P. indica on flowering time in Arabidopsis, we co-cultivated the plants with P. indica under long day condition. P. indica inoculated Arabidopsis plants displayed significant early flowering phenotype. qRT-PCR analysis of colonized plants revealed an up-regulation of flowering regulatory (FLOWERING LOCUS T, LEAFY, and APETALA1) and gibberellin biosynthetic (Gibberellin 20-Oxidase2, Gibberellin 3-Oxidase1 and Gibberellin requiring1) genes, while the flowering-repressing gene FLOWERING LOCUS C was down regulated. Quantification of gibberellins content showed that the colonization with P. indica caused an increase in GA4 content. Compared to wild-type plants, inoculation of the Arabidopsis ga5 mutant affected in gibberellin biosynthetic gene led to less pronounced changes in the expression of genes regulating flowering and to a lower increase in GA4 content. Taken together, our data indicate that P. indica promotes early flowering in Arabidopsis likely by increasing gibberellin content.

  10. Synthesis of methanol from CO2hydrogenation promoted by dissociative adsorption of hydrogen on a Ga3Ni5(221) surface.

    Science.gov (United States)

    Tang, Qingli; Shen, Zhemin; Huang, Liang; He, Ting; Adidharma, Hertanto; Russell, Armistead G; Fan, Maohong

    2017-07-19

    Catalytic carbon dioxide (CO 2 ) hydrogenation to liquid fuels including methanol (CH 3 OH) has attracted great attention in recent years. In this work, density functional theory (DFT) calculations have been employed to study the reaction mechanisms of CO 2 hydrogenation to CH 3 OH on Ga 3 Ni 5 (221) surfaces. The results show that all intermediates except for the O atom prefer to adsorb on Ni sites, and dissociative adsorption of hydrogen (H 2 ) on the Ga 3 Ni 5 (221) surface is almost barrierless and highly exothermic, favoring CO 2 hydrogenation. Moreover, the presence of Ga indeed enhances the dissociative adsorption of H 2 , and this is verified by the projected density of states (PDOS) analysis. Importantly, three possible reaction pathways based on formate (HCOO) and hydrocarboxyl (COOH) formations and reverse water gas shift (rWGS) with carbon monoxide (CO) hydrogenation have been discussed. It is found that CO 2 reduction to CH 3 OH in these pathways prefers to occur entirely via the Langmuir-Hinshelwood (L-H) mechanism. COOH generation is the most favorable pathway because the HCOO and rWGS with CO hydrogenation pathways have high energy barriers and the resulting HCOOH intermediate in the HCOO pathway is unstable. In the COOH reaction pathway, CO 2 is firstly hydrogenated to trans-COOH, followed by the formation of COH via three isomers of COHOH, its hydrogenation to trans-HCOH, and then the production of CH 3 OH via a CH 2 OH intermediate.

  11. Gibberellin hormone signal perception: down-regulating DELLA repressors of plant growth and development

    Science.gov (United States)

    The gibberellin (GA) hormone signal is perceived by a receptor with homology to hormone sensitive lipases, GID1 (GA-INSENSITIVE DWARF1). This leads to GA-stimulated responses including stem elongation, seed germination, and the transition to flowering. GA-binding enables GID1 to interact with and ...

  12. Gibberellin-Abscisic Acid Balances during Arbuscular Mycorrhiza Formation in Tomato

    Czech Academy of Sciences Publication Activity Database

    Martin-Rodriguez, J.A.; Huertas, R.; Ho-Plagaro, T.; Ocampo, J.A.; Turečková, Veronika; Tarkowská, Danuše; Ludwig-Mueller, J.; Garcia-Garrido, J.M.

    2016-01-01

    Roč. 7, AUG 23 (2016), s. 1273 ISSN 1664-462X R&D Projects: GA ČR GA14-34792S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : arbuscular mycorrhiza * plant hormones * gibberellins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.298, year: 2016

  13. Hormonal regulation of gluconeogenesis in cereal aleurone is strongly cultivar-dependent and gibberellin action involves SLENDER1 but not GAMYB.

    Science.gov (United States)

    Eastmond, Peter J; Jones, Russell L

    2005-11-01

    Storage oil is a major constituent in the cereal aleurone layer. The aim of this study was to investigate how gibberellin (GA) and abscisic acid (ABA) regulate conversion of oil to sugar in barley aleurone. The activity of the glyoxylate cycle enzyme isocitrate lyase (ICL) was surveyed in eight barley cultivars. Surprisingly, some cultivars do not require GA for the induction of ICL (e.g. Himalaya), whereas some do (e.g. Golden Promise). Furthermore, in Golden Promise, GA also stimulates triacylglycerol breakdown and enhances the net flux of carbon from acetate to sugar. In contrast, ABA strongly represses ICL activity and the flux of carbon from oil to sugar in both Golden Promise and Himalaya. Biolistics using a promoter reporter showed that GA and ABA regulate ICL at the level of transcription. Studies using barley and rice mutants and pharmacological agents show that GA-dependent induction of ICL activity is mediated by SLENDER1 and requires cGMP, but does not involve the transcription factor GAMYB. Gibberellin and ABA therefore act antagonistically to regulate gluconeogenesis in the aleurone layer as well as controlling the production and secretion of hydrolases into the starchy endosperm. We suggest that the variation between different barley cultivars might be a result of selective breeding to alter seed dormancy.

  14. The synthesis and the luminescence properties of Sr2Ga3La1-xDyxGe3O14

    Science.gov (United States)

    Wang, Qiang; Mu, Zhongfei; Yang, Lurong; Zhang, Shaoan; Zhu, Daoyun; Yang, Yibin; Luo, Dongxiang; Wu, Fugen

    2018-02-01

    A series of Sr2Ga3La1-xDyxGe3O14 (x = 0, 0.015, 0.03, 0.045, 0.06, 0.075, 0.09) phosphors were synthesized by high temperature solid state reactions. X-ray diffraction analysis proves that single-phase Sr2Ga3La1-xDyxGe3O14 (0 ≤ x ≤ 0.09) has been obtained. The particle size of these powders is in the range from 1 to 3 μm. The host Sr2Ga3LaGe3O14 emits blue white light under the excitation of 260 nm ultraviolet light. Dy3+ doped samples can be effectively excited with near ultraviolet light and exhibit two emission bands in the blue (4F9/2 → 6H15/2) and yellow regions (4F9/2 → 6H13/2), which can form white light. Present research indicates that Dy3+ doped Sr2Ga3LaGe3O14 have the potential to be a single-phase full-color emitting phosphor.

  15. Gibberellin-like effects of KAR1 on dormancy release of Avena fatua caryopses include participation of non-enzymatic antioxidants and cell cycle activation in embryos.

    Science.gov (United States)

    Cembrowska-Lech, Danuta; Kępczyński, Jan

    2016-02-01

    The induction of dormancy release and germination of Avena fatua caryopses by KAR 1 involves ABA degradation to phaseic acid. Both, KAR 1 and GA 3 , control the AsA-GSH cycle, DNA replication and accumulation of β-tubulin in embryos before caryopses germination. Avena fatua caryopses cannot germinate in darkness at 20 °C because of dormancy, but karrikinolide-1 (KAR1), a compound in plant-derived smoke, and gibberellic acid (GA3) induced an almost complete germination. The radicle protrusion through the coleorhiza was preceded by increased water uptake, rupture of coat, increased embryo size and coleorhiza length as well as coleorhiza protrusion through covering structures. The stimulatory effect of KAR1 was correlated with the reduced content of abscisic acid (ABA) and an increase in phaseic acid (PA) in embryos from caryopses before coleorhiza protrusion. Two non-enzymatic antioxidants, ascorbate (AsA) and reduced glutathione (GSH), did not affect the germination of dormant caryopses, but in the presence of KAR1 or GA3 they only slightly delayed the germination. The stimulatory effect of KAR1 or GA3 on the final germination percentage was markedly antagonized by lycorine, an AsA biosynthesis inhibitor. KAR1 and GA3 applied during caryopses imbibition resulted in increases of AsA, dehydroascorbate (DHA) and GSH, but reduced the embryos' oxidized glutathione (GSSG) content. Furthermore, both KAR1 and GA3 induced an additional ascorbate peroxidase (APX) isoenzyme and increased the glutathione reductase (GR) activity. Both compounds stimulated β-tubulin accumulation in radicle+coleorhiza (RC) and plumule+coleoptile (PC), and enhanced the transition from G1 to S and also from S to G2 phases. The comparison of the effects produced by KAR1 and GA3  shows a similar action; thus the KAR1 effect may not be specific. The study provides new data regarding the mechanism with which KAR1, a representative of a novel class of plant growth regulators, regulates dormancy and

  16. Biosynthesis of 12α-and 13-hydroxylated gibberellins in a cell-free system from Cucurbita maxima endosperm and the identification of new endogenous gibberellins.

    Science.gov (United States)

    Lange, T; Hedden, P; Graebe, J E

    1993-03-01

    Gibberellin (GA) biosynthesis in cell-free systems from Cucurbita maxima L. endosperm was reinvestigated using incubation conditions different from those employed in previous work. The metabolism of GA12 yielded GA13, GA43 and 12α-hydroxyGA43 as major products, GA4, GA37, GA39, GA46 and four unidentified compounds as minor products. The intermediates GA15, GA24 and GA25 accumulated at low protein concentrations. The structure of the previously uncharacterised 12α-hydroxyGA43 was inferred from its mass spectrum and by its formation from both GA39 and GA43. Gibberellin A39 and 12α-hydroxyGA43 were formed by a soluble 12α-hydroxylase that had not been detected before. Gibberellin A12-aldehyde was metabolised to essentially the same products as GA12 but with less efficiency. A new 13-hydroxylation pathway was found. Gibberellin A53, formed from GA12 by a microsomal oxidase, was converted by soluble 2-oxoglutarate-dependent oxidases to GA1 GA23, GA28, GA44, and putative 2β-hydroxyGA28. Minor products were GA19, GA20, GA38 and three unidentified GAs. Microsomal 13-hydroxylation (the formation of GA53) was suppressed by the cofactors for 2-oxoglutarate-dependent enzymes. Reinvestigation of the endogenous GAs confirmed the significance of the new metabolic products. In addition to the endogenous GAs reported by Blechschmidt et al. (1984, Phytochemistry 23, 553-558), GA1, GA8, GA25, GA28, GA36, GA48 and 12α-hydroxyGA43 were identified by full-scan capillary gas chromatography-mass spectrometry and Kovats retention indices. Thus both the 12α-hydroxylation and the 13-hydroxylation pathways found in the cell-free system operate also in vivo, giving rise to 12α-hydroxyGA43 and GA1 (or GA8), respectively, as their end products. Evidence for endogenous GA20 and GA24 was also obtained but it was less conclusive due to interference.

  17. Gibberellin biosynthetic inhibitors make human malaria parasite Plasmodium falciparum cells swell and rupture to death.

    Directory of Open Access Journals (Sweden)

    Tomoko Toyama

    Full Text Available Malaria remains as one of the most devastating infectious disease, and continues to exact an enormous toll in medical cost and days of labor lost especially in the tropics. Effective malaria control and eventual eradication remain a huge challenge, with efficacious antimalarials as important intervention/management tool. Clearly new alternative drugs that are more affordable and with fewer side effects are desirable. After preliminary in vitro assays with plant growth regulators and inhibitors, here, we focus on biosynthetic inhibitors of gibberellin, a plant hormone with many important roles in plant growth, and show their inhibitory effect on the growth of both apicomplexa, Plasmodium falciparum and Toxoplasma gondii. Treatment of P. falciparum cultures with the gibberellin biosynthetic inhibitors resulted in marked morphological changes that can be reversed to a certain degree under hyperosmotic environment. These unique observations suggest that changes in the parasite membrane permeability may explain the pleiotropic effects observed within the intracellular parasites.

  18. OsGA2ox5, a Gibberellin Metabolism Enzyme, Is Involved in Plant Growth, the Root Gravity Response and Salt Stress

    Science.gov (United States)

    Cai, Weiming; Shan, Chi

    Gibberellin (GA) 2-oxidases play an important role in the GA catabolic pathway through 2b-hydroxylation. There are two classes of GA2oxs, i.e., a larger class of C19-GA2oxs and a smaller class of C20-GA2oxs. In this study, the gene encoding a GA 2-oxidase of rice, Oryza sativa GA 2-oxidase 5 (OsGA2ox5), was cloned and characterized. BLASTP analysis showed that OsGA2ox5 belongs to the C20-GA2oxs subfamily, a subfamily of GA2oxs acting on C20-GAs (GA12, GA53). Subcellular localization of OsGA2ox5-YFP in transiently transformed onion epidermal cells revealed the presence of this protein in both of the nucleus and cytoplasm. Real-time PCR analysis, along with GUS staining, revealed that OsGA2ox5 is expressed in the roots, culms, leaves, sheaths and panicles of rice. Rice plants overexpressing OsGA2ox5 exhibited dominant dwarf and GAdeficient phenotypes, with shorter stems and later development of reproductive organs than the wild type. The dwarfism phenotype was partially rescued by the application of exogenous GA3 at a concentration of 10 mM. Ectopic expression of OsGA2ox5 cDNA in Arabidopsis resulted in a similar phenotype. Real-time PCR assays revealed that both GA synthesis-related genes and GA signaling genes were expressed at higher levels in transgenic rice plants than in wild-type rice; OsGA3ox1, which encodes a key enzyme in the last step of the bioactive GAs synthesis pathway, was highly expressed in transgenic rice. The roots of OsGA2ox5-ox plants exhibited increased starch granule accumulation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Furthermore, rice and Arabidopsis plants overexpressing OsGA2ox5 were more resistant to high-salinity stress than wild-type plants. These results suggest that OsGA2ox5 plays important roles in GAs homeostasis, development, gravity responses and stress tolerance in rice.

  19. Ácido Giberélico (GA3 e maturação de frutos das tangerinas 'Mexerica Montenegrina'e 'Poncã' Gibberellic acid (GA3 and the ripening of 'Ponkan' and 'Montenegrina' mandarin fruits

    Directory of Open Access Journals (Sweden)

    Celso Jamil Marur

    1999-07-01

    Full Text Available Na região norte do estado do Paraná, Brasil, as tangerinas `Ponkan' (Citrus reticulata e `Montenegrina' (Citrus deliciosa geralmente são colhidas em maio e julho, respectivamente. Aplicações de produtos à base de GA3 podem estender o período de produção, permitindo aos produtores programar a colheita e obter melhores preços. Neste trabalho foi estudado o efeito do GA3 sobre a maturação dos frutos de ambas as espécies, nos anos de 1996 e 1997. Os tratamentos constaram de concentrações compreendidas entre 20 e 60 mg L-1 de GA3 aplicadas ao início da mudança de cor dos frutos e quando a coloração alaranjada estava mais avançada. A cada 21 dias a maturação dos frutos foi visualmente avaliada e 6 frutos por parcela foram amostrados para análises do grau Brix e acidez. Com os resultados obtidos, pode-se concluir que a aplicação do produto parece ser mais eficiente quando efetuada no início de mudança de coloração do fruto, por mantê-los verdes por um período maior. Para ambas as espécies parece não ter havido diferenças entre as concentrações do produto, que estenderam o período de colheita por aproximadamente 3 semanas. Verificou-se, também, que o produto aplicado agiu somente na aparência da casca, sem alterar as características do suco.In the North region of the Paraná State, Brazil, 'Ponkan' (Citrus reticulata and 'Montenegrina' (Citrus deliciosa mandarins are usually harvested in May and July, respectively. Application of giberelic acid (GA3 could extend the ripening period, allowing farmers to program harvest to obtain better prices for the fruits. In this work, the effect of GA3 on the maturation of fruits of both species of mandarins, was studied during 1996 and 1997. GA3 was applied at rates between 20 and 60 mg L-1, at the begining of fruit colour change or when the orange colour was more advanced. Every 21 days, the ripening of fruits was visually evaluated and 6 fruits per plot were sampled for

  20. Analysis of gibberellins as free acids by ultra performance liquid chromatography-tandem mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Terezie; Tarkowská, Danuše; Novák, Ondřej; Hedden, P.; Strnad, M.

    2013-01-01

    Roč. 112, č. 2013 (2013), s. 85-94 ISSN 0039-9140 R&D Projects: GA AV ČR KAN200380801 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional research plan: CEZ:AV0Z50380511 Keywords : Gibberellins * Brassica napus * Arabidopsis thaliana Subject RIV: EC - Immunology Impact factor: 3.511, year: 2013

  1. Interactions between ethylene, gibberellins, and brassinosteroids in the development of rhizobial and mycorrhizal symbioses of pea

    Science.gov (United States)

    Foo, Eloise; McAdam, Erin L.; Weller, James L.; Reid, James B.

    2016-01-01

    The regulation of arbuscular mycorrhizal development and nodulation involves complex interactions between the plant and its microbial symbionts. In this study, we use the recently identified ethylene-insensitive ein2 mutant in pea (Pisum sativum L.) to explore the role of ethylene in the development of these symbioses. We show that ethylene acts as a strong negative regulator of nodulation, confirming reports in other legumes. Minor changes in gibberellin1 and indole-3-acetic acid levels in ein2 roots appear insufficient to explain the differences in nodulation. Double mutants produced by crosses between ein2 and the severely gibberellin-deficient na and brassinosteroid-deficient lk mutants showed increased nodule numbers and reduced nodule spacing compared with the na and lk single mutants, but nodule numbers and spacing were typical of ein2 plants, suggesting that the reduced number of nodules in na and lk plants is largely due to the elevated ethylene levels previously reported in these mutants. We show that ethylene can also negatively regulate mycorrhizae development when ethylene levels are elevated above basal levels, consistent with a role for ethylene in reducing symbiotic development under stressful conditions. In contrast to the hormone interactions in nodulation, ein2 does not override the effect of lk or na on the development of arbuscular mycorrhizae, suggesting that brassinosteroids and gibberellins influence this process largely independently of ethylene. PMID:26889005

  2. Low temperature storage of NAA, GA3 and 2,4-D treated citrus budsticks Armazenamento em baixa temperatura de hastes porta-borbulhas de citros tratadas com ANA, GA3 e 2,4-D

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Chamhum Salomão

    2008-01-01

    Full Text Available Cold storage allows citrus budstick conservation for several months, although gradual bud viability loss and abscission of leaf petioles is observed. This study aimed to maintain bud viability reducing leaf petiole abscission in budsticks of 'Baianinha' and 'Valencia' sweet oranges (C. sinensis Osbeck, 'Tahiti' lime (C. latifolia Tanaka, and 'Murcott' tangor (C. sinensis × C. reticulata, using NAA, GA3, 2,4-D, and low temperature storage. After a 15-minutes-immersion in distilled water and NAA and GA3 solutions at concentrations of 10, 100, 500 and 1000 µmol L-1, and 2,4-D solutions at concentrations of 1, 10, 50 and 100 µmol L-1, the shoots were stored in polyethylene bags at 5 ± 1ºC for 74 days. Percentage of leaf petiole abscission, fresh and dry matter losses, bud viability, and growth flush were evaluated. NAA and 2,4-D had the highest efficiency for petiole abscission inhibition, reaching almost 99% of success. The packaging system and shoot storage under low temperature efficiently reduced fresh and dry matter losses. Bud viability of 'Baianinha', 'Valencia' and 'Murcott' shoots was not reduced by storage, maintaining above 95% of grafting success. NAA, GA3 and 2,4-D treatments had no influence on sprout growth.O armazenamento refrigerado possibilita a conservação de hastes porta-borbulhas de citros por vários meses, embora ocorra perda gradual da viabilidade das borbulhas e abscisão dos pecíolos foliares. Este estudo objetivou manter a viabilidade das borbulhas e reduzir a abscisão dos pecíolos foliares das hastes porta-borbulhas das laranjeiras 'Baianinha' e 'Valência'(C. sinensis Osbeck, da lima ácida 'Tahiti'(C. latifolia Tanaka e da tangoreira 'Murcote' (C. sinensis × C. reticulata por meio do tratamento com ANA, GA3, 2,4-D e armazenamento refrigerado. As hastes foram imersas por 15 minutos em água destilada e em soluções com os reguladores de crescimento ANA e GA3 nas concentrações 10, 100, 500 e 1000 µmol L-1 e

  3. Short Communication The efficacy of 6-benzyladenine, gibberellins ...

    African Journals Online (AJOL)

    Fruit size is an important marketing and quality parameter and has a significant effect on the economic value of fruit. The application of synthetic cytokinins are believed to enhance fruit size by stimulating and extending the cell division stage in fruit when applied at the correct time during fruit growth. In addition, a ...

  4. Gibberellin-Regulation and Genetic Variations in Leaf Elongation for Tall Fescue in Association with Differential Gene Expression Controlling Cell Expansion.

    Science.gov (United States)

    Xu, Qian; Krishnan, Sanalkumar; Merewitz, Emily; Xu, Jichen; Huang, Bingru

    2016-07-26

    Leaf elongation rate (LER) is an important factor controlling plant growth and productivity. The objective of this study was to determine whether genetic variation in LER for a fast-growing ('K-31'), and a dwarf cultivar ('Bonsai') of tall fescue (Festuca arundinacea) and gibberellic acid (GA) regulation of LER were associated with differential expression of cell-expansion genes. Plants were treated with GA3, trinexapac-ethyl (TE) (GA inhibitor), or water (untreated control) in a hydroponic system. LER of 'K-31' was 63% greater than that of 'Bonsai', which corresponded with 32% higher endogenous GA4 content in leaf and greater cell elongation and production rates under the untreated control condition. Exogenous application of GA3 significantly enhanced LER while TE treatment inhibited leaf elongation due to GA3-stimulation or TE-inhibition of cell elongation and production rate in leaves for both cultivars. Real-time quantitative polymerase chain reaction analysis revealed that three α-expansins, one β-expansin, and three xyloglucan endotransglycosylase (XET) genes were associated with GA-stimulation of leaf elongation, of which, the differential expression of EXPA4 and EXPA7 was related to the genotypic variation in LER of two cultivars. Those differentially-expressed expansin and XET genes could play major roles in genetic variation and GA-regulated leaf elongation in tall fescue.

  5. Hollow fiber-based liquid-liquid-liquid micro-extraction with osmosis: II. Application to quantification of endogenous gibberellins in rice plant.

    Science.gov (United States)

    Wu, Qian; Wu, Dapeng; Duan, Chunfeng; Shen, Zheng; Guan, Yafeng

    2012-11-23

    The phenomenon and benefits of osmosis in hollow fiber-based liquid-liquid-liquid micro-extraction (HF-LLLME) were theoretically discussed in part I of this study. In this work, HF-LLLME with osmosis was coupled with high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-triple quadrupole MS/MS) to analyze eight gibberellins (gibberellin A(1), gibberellin A(3), gibberellin A(4), gibberellin A(7), gibberellin A(8), gibberellin A(9), gibberellin A(19) and gibberellin A(20)) in rice plant samples. According to the theory of HF-LLLME with osmosis, single factor experiments, orthogonal design experiments and mass transfer simulation of extraction process were carried out to select the optimal conditions. Cyclohexanol - n-octanol (1:3, v/v) was selected as organic membrane. Donor phase of 12 mL was adjusted to pH 2 and 20% NaCl (w/v) was added. Acceptor phase with an initial volume of 20 μL was the solution of 0.12 mol L(-1) Na(2)CO(3)-NaHCO(3) buffer (pH 9). Temperature was chosen to be 30 °C and extraction time was selected to be 90 min. Under optimized conditions, this method provided good linearity (r, 0.99552-0.99991) and low limits of detection (0.0016-0.061 ng mL(-1)). Finally, this method was applied to the analysis of endogenous gibberellins from plant extract which was obtained with traditional solvent extraction of rice plant tissues, and the relative recoveries were from 62% to 166%. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Purification and partial amino-acid sequence of gibberellin 20-oxidase from Cucurbita maxima L. endosperm.

    Science.gov (United States)

    Lange, T

    1994-01-01

    Gibberellin (GA) 20-oxidase was purified to apparent homogeneity from Cucurbita maxima endosperm by fractionated ammonium-sulphate precipitation, gel-filtration chromatography and anion-exchange and hydrophobic-interaction high-performance liquid chromatography (HPLC). Average purification after the last step was 55-fold with 3.9% of the activity recovered. The purest single fraction was enriched 101-fold with 0.2% overall recovery. Apparent relative molecular mass of the enzyme was 45 kDa, as determined by gel-filtration HPLC and sodium dodecyl sulphate-polyacrylamide gel electrophoresis, indicating that GA 20-oxidase is probably a monomeric enzyme. The purified enzyme degraded on two-dimensional gel electrophoresis, giving two protein spots: a major one corresponding to a molecular mass of 30 kDa and a minor one at 45 kDa. The isoelectric point for both was 5.4. The amino-acid sequences of the amino-terminus of the purified enzyme and of two peptides from a tryptic digest were determined. The purified enzyme catalysed the sequential conversion of [14C]GA12 to [14C]GA15, [14C]GA24 and [14C]GA25, showing that carbon atom 20 was oxidised to the corresponding alcohol, aldehyde and carboxylic acid in three consecutive reactions. [14C]Gibberellin A53 was similarly converted to [14C]GA44, [14C]GA19, [14C]GA17 and small amounts of a fourth product, which was preliminarily identified as [14C]GA20, a C19-gibberellin. All GAs except [14C]GA20 were identified by combined gas chromatography-mass spectrometry. The cofactor requirements in the absence of dithiothreitol were essentially as in its presence (Lange et al., Planta 195, 98-107, 1994), except that ascorbate was essential for enzyme activity and the optimal concentration of catalase was lower.

  7. High prevalence of sensitization to gibberellin-regulated protein (peamaclein) in fruit allergies with negative immunoglobulin E reactivity to Bet v 1 homologs and profilin: Clinical pattern, causative fruits and cofactor effect of gibberellin-regulated protein allergy.

    Science.gov (United States)

    Inomata, Naoko; Miyakawa, Mami; Aihara, Michiko

    2017-07-01

    Gibberellin-regulated protein (GRP) is a new allergen in peach allergy, with an amino acid sequence very well conserved through several botanical species. We investigated the allergenicity of GRP in fruit allergies other than peaches and identified the clinical characteristics of fruit allergy patients with GRP sensitization. One hundred consecutive Japanese patients with fruit allergies were enrolled in the present study. To identify the features of GRP sensitization, we selected patients with negative ImmunoCAP results for Bet v 1 homologs and profilin, which are marker allergens for pollen-food allergy syndrome (PFAS), or lipid transfer protein. These patients underwent specific immunoglobulin E measurements by enzyme-linked immunosorbent assay (ELISA) and skin prick tests (SPT) using purified nPru p 7. Twenty of 100 consecutive patients with fruit allergies had negative ImmunoCAP results for Bet v 1 homologs and profilin. Thirteen (65.0%) of the 20 patients had positive ELISA and/or SPT results using nPru p 7, whereas one of the 20 patients had positive ImmunoCAP results for Pru p 3. In 13 nPru p 7-sensitized patients, the causative foods were peaches (92.3%), apricots (61.5%), oranges (46.2%) and apples (30.8%). Ten patients (76.9%) had multiple causative fruits. Frequent symptoms included facial edema (92.3%) and laryngeal tightness (66.7%). In eight patients (61.5%), exercise or aspirin intake enhanced the allergic reaction onset as cofactors. The prevalence of GRP sensitization was high in Japanese fruit allergy patients except for PFAS patients. In conclusion, GRP-sensitized patients may have allergies to multiple fruits and may show peculiar characteristics such as facial swelling and cofactor dependence. © 2017 Japanese Dermatological Association.

  8. Superconductivity and magnetism in heavy-fermion UPd2(Al,Ga)3

    Science.gov (United States)

    Süllow, S.; Ludoph, B.; Becker, B.; Nieuwenhuys, G. J.; Menovsky, A. A.; Mydosh, J. A.

    1997-07-01

    We present bulk properties (resistivity, specific heat, and susceptibility) of the quasiternary system UPd2(Al1-xGax)3 and derive the superconducting and magnetic phase diagrams. For low Ga substitution (xx the magnetic transition temperature TN gradually decreases, and the mass enhancement of the electrons increases, until at x=0.8-0.9 a crystallographic transition takes place from the PrNi2Al3 to the BaB2Pt3 lattice. At the structural transition TN discontinuously increases, while the electronic specific heat γ grows smoothly through the transition. We discuss the relationship between the alloying parameter x and the magnetic ordering and electronic hybridization, respectively. The strong suppression of the superconductivity in UPd2Al3 with Ga suggests an unconventional mechanism of superconductivity, most probably related to spin fluctuations mediating the pairing.

  9. Gibberellins regulate iron deficiency-response by influencing iron transport and translocation in rice seedlings (Oryza sativa).

    Science.gov (United States)

    Wang, Baolan; Wei, Haifang; Xue, Zhen; Zhang, Wen-Hao

    2017-04-01

    Gibberellins (GAs) are a class of plant hormones with diverse functions. However, there has been little information on the role of GAs in response to plant nutrient deficiency. To evaluate the roles of GAs in regulation of Fe homeostasis, the effects of GA on Fe accumulation and Fe translocation in rice seedlings were investigated using wild-type, a rice mutant ( eui1 ) displaying enhnaced endogenous GA concentrations due to a defect in GA deactivation, and transgenic rice plants overexpressing OsEUI . Exposure to Fe-deficient medium significantly reduced biomass of rice plants. Both exogenous application of GA and an endogenous increase of bioactive GA enhanced Fe-deficiency response by exaggerating foliar chlorosis and reducing growth. Iron deficiency significantly suppressed production of GA 1 and GA 4 , the biologically active GAs in rice. Exogenous application of GA significantly decreased leaf Fe concentration regardless of Fe supply. Iron concentration in shoot of eui1 mutants was lower than that of WT plants under both Fe-sufficient and Fe-deficient conditions. Paclobutrazol, an inhibitor of GA biosynthesis, alleviated Fe-deficiency responses, and overexpression of EUI significantly increased Fe concentration in shoots and roots. Furthermore, both exogenous application of GA and endogenous increase in GA resulting from EUI mutation inhibited Fe translocation within shoots by suppressing OsYSL2 expression, which is involved in Fe transport and translocation. The novel findings provide compelling evidence to support the involvement of GA in mediation of Fe homeostasis in strategy II rice plants by negatively regulating Fe transport and translocation. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  10. Gibberellin-induced changes in the populations of translatable mRNAs and accumulated polypeptides in dwarfs of maize and pea

    International Nuclear Information System (INIS)

    Chory, J.; Voytas, D.F.; Olszewski, N.E.; Ausubel, F.M.

    1987-01-01

    Two-dimensional gel electrophoresis was used to characterize the molecular mechanism of gibberellin-induced stem elongation in maize and pea. Dwarf mutants of maize and pea lack endogenous gibberellin (GA 1 ) but become phenotypically normal with exogenous applications of this hormone. Sections from either etiolated maize or green pea seedlings were incubated in the presence of [ 35 S] methionine for 3 hours with or without gibberellin. Labeled proteins from soluble and particulate fractions were analyzed by two-dimensional gel electrophoresis and specific changes in the patterns of protein synthesis were observed upon treatment with gibberellin. Polyadenylated mRNAs from etiolated or green maize shoots and green pea epicotyls treated or not with gibberellin (a 0.5 to 16 hour time course) were assayed by translation in a rabbit reticulocyte extract and separation of products by two-dimensional gel electrophoresis. Both increases and decreases in the levels of specific polypeptides were seen for pea and corn, and these changes were observed within 30 minutes of treatment with gibberellin. Together, these data indicate that gibberellin induces changes in the expression of a subset of gene products within elongating dwarfs. This may be due to changes in transcription rate, mRNA stability, or increased efficiency of translation of certain mRNAs

  11. Characterization of novel mutants with an altered gibberellin spectrum in comparison to different wild-type strains of Fusarium fujikuroi.

    Science.gov (United States)

    Albermann, Sabine; Elter, Tino; Teubner, Andreas; Krischke, Wolfgang; Hirth, Thomas; Tudzynski, Bettina

    2013-09-01

    The rice pathogen Fusarium fujikuroi is known for producing a wide range of secondary metabolites such as pigments, mycotoxins, and a group of phytohormones, the gibberellic acids (GAs). Bioactive forms of these diterpenes are responsible for hyperelongation of rice stems, yellowish chlorotic leaves, and reduced grain formation during the bakanae disease leading to severely decreased crop yields. GAs are also successfully applied in agriculture and horticulture as plant growth regulators to enhance crop yields, fruit size, and to induce earlier flowering. In this study, six F. fujikuroi wild-type and mutant strains differing in GA yields and the spectrum of produced GAs were cultivated in high-quality lab fermenters for optimal temperature and pH control and compared regarding their growth, GA production, and GA gene expression levels. Comparative analysis of the six strains revealed that strain 6314/ΔDES/ΔPPT1, holding mutations in two GA biosynthetic genes and an additional deletion of the 4'-phosphopantetheinyl transferase gene PPT1, exhibits the highest total GA amount. Expression studies of two GA biosynthesis genes, CPS/KS and DES, showed a constantly high expression level for both genes under production conditions (nitrogen limitation) in all strains. By cultivating these genetically engineered mutant strains, we were able to produce not only mixtures of different bioactive GAs (GA3, GA4, and GA7) but also pure GA4 or GA7. In addition, we show that the GA yields are not only determined by different production rates, but also by different decomposition rates of the end products GA3, GA4, and GA7 explaining the varying GA levels of genetically almost identical mutant strains.

  12. Further identification of endogenous gibberellins in the shoots of pea, line G2

    International Nuclear Information System (INIS)

    Halinska, A.; Davies, P.J.; Lee, J.W.; Zhu, Yuxian

    1989-01-01

    To interpret the metabolism of radiolabeled gibberellins A 12 -aldehyde and A 12 in shoots of pea (Pisum sativum L.), the identity of the radiolabeled peaks has to be determined and the endogenous presence of the gibberellins demonstrated. High specific activity [ 14 C]GA 12 and [ 14 C]GA 12 -aldehyde were synthesized using a pumpkin endosperm enzyme preparation, and purified by high performance liquid chromatography (HPLC). [ 14 C]GA 12 was supplied to upper shoots of pea, line G2, to produce radiolabeled metabolites on the 13-OH pathway. Endogenous compounds copurifying with the [ 14 C]GAs on HPLC were analyzed by gas chromatography-mass spectrometry. The endogenous presence of GA 53 , GA 44 , GA 19 and GA 20 was demonstrated and their HPLC peak identity ascertained. The 14 C was progressively diluted in GAs further down the pathway, proportional to the levels found in the tissue and inversely proportional to the speed of metabolism, ranging from 63% in GA 53 to 4% in GA 20 . Calculated levels of GA 20 , GA 19 , GA 44 , and GA 53 were 42, 8, 10, and 0.5 nanograms/gram, respectively

  13. The Involvement of Gibberellins in 1,8-Cineole-Mediated Inhibition of Sprout Growth in Russet Burbank Tubers

    Science.gov (United States)

    The involvement of gibberellins in 1,8-cineole-mediated inhibition of tuber sprout growth was investigated in non-dormant field- and greenhouse-grown tubers of Russet Burbank. Continuous exposure of tubers to cineole in the vapor-phase resulted in a dose-dependent inhibition of sprout growth. Comp...

  14. Transformation of a Dwarf "Arabidopsis" Mutant Illustrates Gibberellin Hormone Physiology and the Function of a Green Revolution Gene

    Science.gov (United States)

    Molina, Isabel; Weber, Katrin; Alves Cursino dos Santos, Deborah Y.; Ohlrogge, John

    2009-01-01

    The introduction of dwarfing traits into crops was a major factor in increased grain yields during the "Green Revolution." In most cases those traits were the consequence of altered synthesis or response to the gibberellin (GA) plant hormones. Our current understanding of GA synthesis and physiology has been facilitated by the characterization of…

  15. Hormonal regulation of seed development and germination in tomato : studies on abscisic acid- and gibberellin-deficient mutants

    NARCIS (Netherlands)

    Groot, S.P.C.

    1987-01-01

    The role of endogenous gibberellins (GAs) and abscisic acid (ABA) in seed development and germination of tomato, was studied with the use of GA- and/or ABA-deficient mutants.

    GAs are indispensable for the development of fertile flowers. Fertility of GA-deficient flowers is restored

  16. Induction of chilling tolerance in wheat during germination by pre-soaking seed with nitric oxide and gibberellin

    DEFF Research Database (Denmark)

    Li, Xiangnan; Jiang, Haidong; Liu, Fulai

    2013-01-01

    Chilling depresses seed germination and seedling establishment, and is one major constraint to grain yield formation in late sown winter wheat. Seeds of winter wheat (Triticum aestivum L.) were separately pre-soaked with sodium nitroprusside (SNP, as nitric oxide donor) and Gibberellic acid (GA3......) before germination and then germinated under low temperature. SNP and GA3 pre-treatment increased seed germination rate, germination index, weights and lengths of coleoptile and radicle, while they decreased mean germination time and weight of seeds germinating under low temperature. Exogenous NO and GA3...... by exogenous NO and GA3 as a result of improved seed germination and maintenance of better reactive oxygen species homeostasis in seedling growing under chilling temperatures. It is indicated that exogenous NO was more effective than GA3 in alleviating chilling stress during seed germination and seedling...

  17. Luminescence and light yield of (Gd2Y)(Ga3Al2)O12:Pr3+ single crystal scintillators

    Science.gov (United States)

    Lertloypanyachai, Prapon; Pathumrangsan, Nichakorn; Sreebunpeng, Krittiya; Pattanaboonmee, Nakarin; Chewpraditkul, Weerapong; Yoshikawa, Akira; Kamada, Kei; Nikl, Martin

    2017-06-01

    Praseodymium-doped (Gd2Y)(Ga3Al2)O12 (GYGAG: Pr) single crystals are grown by the micro-pulling down method with different Pr concentrations. The energy transfer process between Pr3+ and Gd3+ is investigated by photoluminescence excitation (PLE) and emission (PL) spectra measurements. Photoelectron yield measurements are carried out using photomultiplier. At 662 keV γ-rays, photoelectron yield of 2520 phe/MeV obtained for the GYGAG: Pr (0.01%) sample is larger than that of 1810 phe/MeV obtained for BGO crystal. Light yield degradation for the GYGAG: Pr scintillators is presumably due to the energy transfer from 5d state of Pr3+ to 4f state of Gd3+ together with the concentration quenching in the Gd3+-sublattice.

  18. Genome-wide identification and expression profiling reveal tissue-specific expression and differentially-regulated genes involved in gibberellin metabolism between Williams banana and its dwarf mutant.

    Science.gov (United States)

    Chen, Jingjing; Xie, Jianghui; Duan, Yajie; Hu, Huigang; Hu, Yulin; Li, Weiming

    2016-05-27

    Dwarfism is one of the most valuable traits in banana breeding because semi-dwarf cultivars show good resistance to damage by wind and rain. Moreover, these cultivars present advantages of convenient cultivation, management, and so on. We obtained a dwarf mutant '8818-1' through EMS (ethyl methane sulphonate) mutagenesis of Williams banana 8818 (Musa spp. AAA group). Our research have shown that gibberellins (GAs) content in 8818-1 false stems was significantly lower than that in its parent 8818 and the dwarf type of 8818-1 could be restored by application of exogenous GA3. Although GA exerts important impacts on the 8818-1 dwarf type, our understanding of the regulation of GA metabolism during banana dwarf mutant development remains limited. Genome-wide screening revealed 36 candidate GA metabolism genes were systematically identified for the first time; these genes included 3 MaCPS, 2 MaKS, 1 MaKO, 2 MaKAO, 10 MaGA20ox, 4 MaGA3ox, and 14 MaGA2ox genes. Phylogenetic tree and conserved protein domain analyses showed sequence conservation and divergence. GA metabolism genes exhibited tissue-specific expression patterns. Early GA biosynthesis genes were constitutively expressed but presented differential regulation in different tissues in Williams banana. GA oxidase family genes were mainly transcribed in young fruits, thus suggesting that young fruits were the most active tissue involved in GA metabolism, followed by leaves, bracts, and finally approximately mature fruits. Expression patterns between 8818 and 8818-1 revealed that MaGA20ox4, MaGA20ox5, and MaGA20ox7 of the MaGA20ox gene family and MaGA2ox7, MaGA2ox12, and MaGA2ox14 of the MaGA2ox gene family exhibited significant differential expression and high-expression levels in false stems. These genes are likely to be responsible for the regulation of GAs content in 8818-1 false stems. Overall, phylogenetic evolution, tissue specificity and differential expression analyses of GA metabolism genes can provide a

  19. Combination of the auxins NAA, IBA, and IAA with GA3 improves the commercial seed-tuber production of potato (Solanum tuberosum L.) under in vitro conditions.

    Science.gov (United States)

    Kumlay, Ahmet Metin

    2014-01-01

    The study compared the effects of 1.0 × MS medium containing various concentrations of α-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA), alone or in combination with gibberellic acid (GA3) in micropropagation of three potato (Solanum tuberosum L.) cultivars Pasinler, Granola, and Caspar using binodal stem cuttings. The results testified improved regeneration on 1.0 × MS medium containing variants of NAA, IAA, and IBA plus GA3 on all cultivars. The minimum days to shoot induction on three cultivars ranged 4.25-5 d on 1.0 × MS medium containing 0.25 mg L(-1) GA3 + 1 mg L(-1) NAA. The longest shoots (11.8 cm), maximum number of nodes (13.50), and maximum number of leaves (11.00) were recorded on cv. Caspar on 1.0 × MS medium containing 1 mg L(-1) NAA + 0.25 mg L(-1) GA3. The minimum time to root induction (12.25 d) was noted on cv. Pasinler on the same medium. All of the regenerated shoots could be easily rooted. The results showed that the combined effect of various concentrations of NAA, IAA, and IBA plus GA3 was more pronounced compared to the auxins used alone. The results of this research are of significant importance for potato breeders.

  20. Independent Control of Gibberellin Biosynthesis and Flowering Time by the Circadian Clock in Arabidopsis1

    Science.gov (United States)

    Blázquez, Miguel A.; Trénor, Marta; Weigel, Detlef

    2002-01-01

    Flowering of the facultative long-day plant Arabidopsis is controlled by several endogenous and environmental factors, among them gibberellins (GAs) and day length. The promotion of flowering by long days involves an endogenous clock that interacts with light cues provided by the environment. Light, and specifically photoperiod, is also known to regulate the biosynthesis of GAs, but the effects of GAs and photoperiod on flowering are at least partially separable. Here, we have used a short-period mutant, toc1, to investigate the role of the circadian clock in the control of flowering time by GAs and photoperiod. We show that toc1 affects expression of several floral regulators and a GA biosynthetic gene, but that these effects are independent. PMID:12481060

  1. The Arabidopsis GAI gene defines a signaling pathway that negatively regulates gibberellin responses.

    Science.gov (United States)

    Peng, J; Carol, P; Richards, D E; King, K E; Cowling, R J; Murphy, G P; Harberd, N P

    1997-12-01

    The Arabidopsis gai mutant allele confers a reduction in gibberellin (GA) responsiveness. Here we report the molecular cloning of GAI and a closely related gene GRS. The predicted GAI (wild-type) and gai (mutant) proteins differ only by the deletion of a 17-amino-acid segment from within the amino-terminal region. GAI and GRS contain nuclear localization signals, a region of homology to a putative transcription factor, and motifs characteristic of transcriptional coactivators. Genetic analysis indicates that GAI is a repressor of GA responses, that GA can release this repression, and that gai is a mutant repressor that is relatively resistant to the effects of GA. Mutations at SPY and GAR2 suppress the gai phenotype, indicating the involvement of GAI, SPY, and GAR2 in a signaling pathway that regulates GA responses negatively. The existence of this pathway suggests that GA modulates plant growth through derepression rather than through simple stimulation.

  2. In Vivo Gibberellin Biosynthesis in Endosperm of Sechium edule Sw. Seeds

    Science.gov (United States)

    Ceccarelli, Nello; Lorenzi, Roberto

    1990-01-01

    Biosynthesis of gibberellins (GAs) was studied in vivo in endosperms of Sechium edule Sw. Exogenous ent-[14C]kaurene was metabolized into four major products: GA12, GA4, GA7 and 16, 17-dihydro-16-hydroxy-GA15 alcohol glucoside. Other minor metabolites were also observed including ent-kaurenol and ent-kaurenal. Conversion of ent-[14C]kaurene to ent-kaurenol glucoside by endosperm cell-free preparations in the presence of UDPG was observed. However, the finding was not confirmed in in vivo studies and is probably artifactual. Overall evidence coming from the analysis of endogenous GAs and in vitro and in vivo biosynthetic studies are discussed in relation to the possible existence in the Sechium seeds of a different route, along with the known pathway, branching from ent-kaurene or ent-7-α-hydroxykaurenoic acid and this also leading to biologically active GAs. PMID:16667553

  3. In Vivo Gibberellin Biosynthesis in Endosperm of Sechium edule Sw. Seeds.

    Science.gov (United States)

    Ceccarelli, N; Lorenzi, R

    1990-07-01

    Biosynthesis of gibberellins (GAs) was studied in vivo in endosperms of Sechium edule Sw. Exogenous ent-[(14)C]kaurene was metabolized into four major products: GA(12), GA(4), GA(7) and 16, 17-dihydro-16-hydroxy-GA(15) alcohol glucoside. Other minor metabolites were also observed including ent-kaurenol and ent-kaurenal. Conversion of ent-[(14)C]kaurene to ent-kaurenol glucoside by endosperm cell-free preparations in the presence of UDPG was observed. However, the finding was not confirmed in in vivo studies and is probably artifactual. Overall evidence coming from the analysis of endogenous GAs and in vitro and in vivo biosynthetic studies are discussed in relation to the possible existence in the Sechium seeds of a different route, along with the known pathway, branching from ent-kaurene or ent-7-alpha-hydroxykaurenoic acid and this also leading to biologically active GAs.

  4. Role of Endogenous Plant Growth Regulators in Seed Dormancy of Avena fatua: II. Gibberellins.

    Science.gov (United States)

    Metzger, J D

    1983-11-01

    Gibberellin A(1) (GA(1)) was identified by combined gas chromatographymass spectrometry as the major biologically active gibberellin (GA) in seeds of wild oat (Avena fatua L.) regardless of the depth of dormany or stage of imbibition. Both unimbibed dormant and nondromant seeds contained similar amounts of GA(1) as estimated by the d5-maize bioassay. During imbibition, the level of GA(1) declined in both dormant and non-dormant seeds, although the decline was more rapid in dormant seeds. Only in imbibing nondormant seeds did the GA biosynthesis inhibitor, 2-chloroethyltrimethyl ammonium chloride (CCC), cause a reduction in the level of GA(1) from that observed in control seeds. These results are interpreted as an indication that while afterripening does not cause a direct change in the levels of GAs during dry storage, it does induce a greater capacity for GA biosynthesis during imbibition.Nondormant seeds imbibed in the presence of 50 millimolar CCC germinated equally as well as untreated seeds. When wild oat plants were fed CCC throughout the entire life cycle, viable seeds were produced that lacked detectable GA-like substances. These seeds afterripened at a slightly slower rate than the controls. Moreover, completely afterripened (nondormant) seeds from plants fed CCC continuously contained no detectable GA-like substances, and when these seeds germinated, dwarf seedlings were produced, indicating GA biosynthesis was inhibited during and after germination. In total, these results suggest that the increased capacity for GA biosynthesis observed in imbibing nondormant seeds is not a necessary prerequisite for germination. It is therefore possible that GA biosynthesis in imbibing nondormant seeds is one of many coordinated biochemical events that occur during germination rather than an initiator of the processes leading to germination.

  5. Data in support of Gallium (Ga3+ antibacterial activities to counteract E. coli and S. epidermidis biofilm formation onto pro-osteointegrative titanium surfaces

    Directory of Open Access Journals (Sweden)

    A. Cochis

    2016-03-01

    In this article we included an indirect cytocompatibility evaluation towards Saos2 human osteoblasts and extended the microbial evaluation of the Ga3+ enriched titanium surfaces against the biofilm former Escherichia coli and Staphylococcus epidermidis strains. Cell viability was assayed by the Alamar Blue test, while bacterial viability was evaluated by the metabolic colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT assay. Finally biofilm morphology was analyzed by Scanning Electron Microscopy (SEM. Data regarding Ga3+ activity were compared to Silver.

  6. The Effects of Stratification Periods and GA3 (Gibberellic acid) Applicatıons on Germination of Seeds of Some Grape Cultivars

    OpenAIRE

    ÇELİK, Mustafa

    2015-01-01

    It is neccessery to know the effects of applications increasing the percentage of seed germination for assisting the breeding researches. The aim of this research is to determine the effects of different doses of GA3(Gibberellic acid) and different cold stratification times on germination abilities of the seeds of Gelin, Razakı and Alphonse Lavallee cv. (Vitis vinifera L.). 75 and 90 days stratification periods at +5ºC together with 0, 250 and 750 ppm GA3 doses have been applied in completely...

  7. Metabolism of [3H]Gibberellin A20 by plants of Bryophyllum daigremontianum under long- and short-day conditions

    International Nuclear Information System (INIS)

    Durley, R.C.; Pharis, R.P.; Zeevaart, J.A.D.

    1975-01-01

    [ 3 H]Gibberellin A 20 ([ 3 H]GA 20 ), a native gibberellin of this plant, was injected into mature leaves of Bryophyllum daigremontianum (Hamet et Perr.) Berg. under long- and short-day conditions. It was converted, in order of decreasing yields, to GA 29 , 3-epi-GA 1 (pseudo GA 1 ), C/D-ring-rearranged GA 20 , and two minor, unidentified metabolites. Identifications were made by gas-liquid chromatography with radioactive monitoring using three different phases. Metabolism to 3-epi-GA 1 was greater under short days, particularly in the treated leaf pair, although the absolute amount of GA 29 was greater than that of 3-epi-GA 1 under both photoperiods. The levels of radioactive metabolites in the shoots above the treated leaf pair gradually increased over a 51-day period, GA 29 reaching 5 times the content of 3-epi-GA 1 . (orig.) [de

  8. Gibberellin-to-abscisic acid balances govern development and differentiation of the nucellar projection of barley grains

    Czech Academy of Sciences Publication Activity Database

    Weier, D.; Thiel, J.; Kohl, S.; Tarkowská, Danuše; Strnad, Miroslav; Schaarschmidt, S.; Weschke, W.; Weber, H.; Hause, B.

    2014-01-01

    Roč. 65, č. 18 (2014), s. 5291-5304 ISSN 0022-0957 R&D Projects: GA MŠk LK21306 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional support: RVO:61389030 Keywords : Assimilate transfer * barley endosperm * gibberellin-to- abscisic acid balances Subject RIV: EF - Botanics Impact factor: 5.526, year: 2014

  9. The mitochondrial phosphate transporters modulate plant responses to salt stress via affecting ATP and gibberellin metabolism in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Wei Zhu

    Full Text Available The mitochondrial phosphate transporter (MPT plays crucial roles in ATP production in plant cells. Three MPT genes have been identified in Arabidopsis thaliana. Here we report that the mRNA accumulations of AtMPTs were up-regulated by high salinity stress in A. thaliana seedlings. And the transgenic lines overexpressing AtMPTs displayed increased sensitivity to salt stress compared with the wild-type plants during seed germination and seedling establishment stages. ATP content and energy charge was higher in overexpressing plants than those in wild-type A. thaliana under salt stress. Accordingly, the salt-sensitive phenotype of overexpressing plants was recovered after the exogenous application of atractyloside due to the change of ATP content. Interestingly, Genevestigator survey and qRT-PCR analysis indicated a large number of genes, including those related to gibberellin synthesis could be regulated by the energy availability change under stress conditions in A. thaliana. Moreover, the exogenous application of uniconazole to overexpressing lines showed that gibberellin homeostasis was disturbed in the overexpressors. Our studies reveal a possible link between the ATP content mediated by AtMPTs and gibberellin metabolism in responses to high salinity stress in A. thaliana.

  10. Synergism between demethylation inhibitor fungicides or gibberellin inhibitor plant growth regulators and bifenthrin in a pyrethroid-resistant population of Listronotus maculicollis (Coleoptera: Curculionidae).

    Science.gov (United States)

    Ramoutar, D; Cowles, R S; Requintina, E; Alm, S R

    2010-10-01

    In 2007-2008, the "annual bluegrass weevil," Listronotus maculicollis Kirby (Coleoptera: Curculionidae), a serious pest of Poa annua L. (Poales: Poaceae) on U.S. golf courses, was shown to be resistant to two pyrethroids, bifenthrin and lambda-cyhalothrin. In 2008, we showed that bifenthrin resistance was principally mediated by oxidase detoxification (cytochrome P450 [P450]). P450s can be inhibited by demethylation inhibitor fungicides and gibberellin inhibitor plant growth regulators, both of which are commonly used on golf courses. We tested these compounds for synergistic activity with bifenthin against a pyrethroid-resistant population of L. maculicollis. The LD50 value for bifenthrin was significantly reduced from 87 ng per insect (without synergists) to 9.6-40 ng per insect after exposure to the fungicides fenarimol, fenpropimorph, prochloraz, propiconazole, and pyrifenox and the plant growth regulators flurprimidol, paclobutrazol, and trinexapac-ethyl. Simulated field exposure with formulated products registered for use on turf revealed enhanced mortality when adult weevils were exposed to bifenthrin (25% mortality, presented alone) combined with field dosages of propiconizole, fenarimol, flurprimidol, or trinexapac-ethyl (range, 49-70% mortality).

  11. Synthesis, Structure, and Electrical Property of Ce1−xSr1+xGa3O7−δ

    Directory of Open Access Journals (Sweden)

    Xiaohui Li

    2015-01-01

    Full Text Available Ce1−xSr1+xGa3O7−δ powders were synthesized by a solid state reaction method under reducing atmosphere. Single melilite phase was obtained for x≤0.2. X-ray diffraction pattern displays a preferred orientation on (002 peak of the Ce0.9Sr1.1Ga3O7−δ composition. Scanning electron microscope disclosed the nanoscale needle-like micromorphology of this material, with an average length of ~2.5 μm and a diameter of ~500 nm. Transmission electron microscopy and selected area electron diffraction reveal the single crystal nature of these individual Ce0.9Sr1.1Ga3O7−δ needles and build up a relationship between the preferred orientation observed in X-ray diffraction pattern and the micromorphology. The phase stability of Ce1−xSr1+xGa3O7−δ in air was studied and the electrical property was investigated by impedance spectroscopy.

  12. Effect of GA3 and 2,4-D foliar application on the anatomy of date palm (Phoenix dactylifera L.) seedling leaf.

    Science.gov (United States)

    Doaigey, Abdullah R; Al-Whaibi, M H; Siddiqui, M H; Al Sahli, A A; El-Zaidy, M E

    2013-04-01

    Two concentrations (10-5M and 10-3M) of both GA3 and 2,4-D were used as foliar spray to evaluate the response of date palm (Phoenix dactylifera L.) cv. Khedri seedlings. They affected some of the anatomical characteristics of the first leaf emerging after the beginning of the spray. The high concentration of GA3 increased the size of the midrib and its vascular bundle numbers. Both low and high concentrations of 2,4-D inhibited the formation of the midrib. 2,4-D in both low and high concentrations decreased the number of vessels in both protoxylem and metaxylem and also decreased their diameters, where as GA3 in low and high concentrations have less effect on the number of vessels and its diameters. GA3 in high concentration increased the number of vascular bundles in 1mm long of the leaf blade, while 2,4-D in low and high concentrations decreased their numbers. 10-3M of 2,4-D increased the size and layers of special hypodermal cells.

  13. Combination of the Auxins NAA, IBA, and IAA with GA3 Improves the Commercial Seed-Tuber Production of Potato (Solanum tuberosum L. under In Vitro Conditions

    Directory of Open Access Journals (Sweden)

    Ahmet Metin Kumlay

    2014-01-01

    Full Text Available The study compared the effects of 1.0×MS medium containing various concentrations of α-naphthaleneacetic acid (NAA, indole-3-acetic acid (IAA, and indole-3-butyric acid (IBA, alone or in combination with gibberellic acid (GA3 in micropropagation of three potato (Solanum tuberosum L. cultivars Pasinler, Granola, and Caspar using binodal stem cuttings. The results testified improved regeneration on 1.0×MS medium containing variants of NAA, IAA, and IBA plus GA3 on all cultivars. The minimum days to shoot induction on three cultivars ranged 4.25–5 d on 1.0×MS medium containing 0.25 mg L−1  GA3+1 mg L−1 NAA. The longest shoots (11.8 cm, maximum number of nodes (13.50, and maximum number of leaves (11.00 were recorded on cv. Caspar on 1.0×MS medium containing 1 mg L−1  NAA+0.25 mg L−1 GA3. The minimum time to root induction (12.25 d was noted on cv. Pasinler on the same medium. All of the regenerated shoots could be easily rooted. The results showed that the combined effect of various concentrations of NAA, IAA, and IBA plus GA3 was more pronounced compared to the auxins used alone. The results of this research are of significant importance for potato breeders.

  14. MADS-box genes and gibberellins regulate bolting in lettuce (Lactuca sativa L.

    Directory of Open Access Journals (Sweden)

    Yingyan Han

    2016-12-01

    Full Text Available Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines.

  15. MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativaL.).

    Science.gov (United States)

    Han, Yingyan; Chen, Zijing; Lv, Shanshan; Ning, Kang; Ji, Xueliang; Liu, Xueying; Wang, Qian; Liu, Renyi; Fan, Shuangxi; Zhang, Xiaolan

    2016-01-01

    Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs. S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA) treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines.

  16. Comparison of Effect of Brassinosteroid and Gibberellin Biosynthesis Inhibitors on Growth of Rice Seedlings

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    Tadashi Matusmoto

    2016-01-01

    Full Text Available Brassinosteroid (BR and gibberellin (GA are two predominant plant hormones that regulate plant cell elongation. Mutants disrupt the biosynthesis of these hormones and display different degrees of dwarf phenotypes in rice. Although the role of each plant hormone in promoting the longitudinal growth of plants has been extensively studied using genetic methods, their relationship is still poorly understood. In this study, we used two specific inhibitors targeting BR and GA biosynthesis to investigate the roles of BR and GA in growth of rice seedlings. Yucaizol, a specific inhibitor of BR biosynthesis, and Trinexapac-ethyl, a commercially available inhibitor of GA biosynthesis, were used. The effect of Yucaizol on rice seedlings indicated that Yucaizol significantly retarded stem elongation. The IC50 value was found to be approximately 0.8 μmol/L. Yucaizol also induced small leaf angle phenocopy in rice seedlings, similarly to BR-deficient rice, while Trinexapac-ethyl did not. When Yucaizol combined with Trinexapac-ethyl was applied to the rice plants, the mixture of these two inhibitors retarded stem elongation of rice at lower doses. Our results suggest that the use of a BR biosynthesis inhibitor combined with a GA biosynthesis inhibitor may be useful in the development of new technologies for controlling rice plant height.

  17. 2-Oxoglutarate: linking TCA cycle function with amino acid, glucosinolate, flavonoid, alkaloid, and gibberellin biosynthesis.

    Science.gov (United States)

    Araújo, Wagner L; Martins, Auxiliadora O; Fernie, Alisdair R; Tohge, Takayuki

    2014-01-01

    The tricarboxylic acid (TCA) cycle intermediate 2-oxoglutarate (2-OG) is used as an obligatory substrate in a range of oxidative reactions catalyzed by 2-OG-dependent dioxygenases. These enzymes are widespread in nature being involved in several important biochemical processes. We have recently demonstrated that tomato plants in which the TCA cycle enzyme 2-OG dehydrogenase (2-ODD) was antisense inhibited were characterized by early senescence and modified fruit ripening associated with differences in the levels of bioactive gibberellin (GA). Accordingly, there is now compelling evidence that the TCA cycle plays an important role in modulating the rate of flux from 2-OG to amino acid metabolism. Here we discuss recent advances in the biochemistry and molecular biology of 2-OG metabolism occurring in different biological systems indicating the importance of 2-OG and 2-OG dependent dioxygenases not only in glucosinolate, flavonoid and alkaloid metabolism but also in GA and amino acid metabolism. We additionally summarize recent findings regarding the impact of modification of 2-OG metabolism on biosynthetic pathways involving 2-ODDs.

  18. 2-Oxoglutarate: linking TCA cycle function with amino acid, glucosinolate, flavonoid, alkaloid and gibberellin biosynthesis

    Directory of Open Access Journals (Sweden)

    Wagner L. Araújo

    2014-10-01

    Full Text Available The tricarboxylic acid (TCA cycle intermediate 2-oxoglutarate (2-OG is used as an obligatory substrate in a range of oxidative reactions catalyzed by 2-OG-dependent dioxygenases. These enzymes are widespread in nature being involved in several important biochemical processes. We have recently demonstrated that tomato plants in which the TCA cycle enzyme 2-OG dehydrogenase (2-ODD was antisense inhibited were characterized by early senescence and modified fruit ripening associated with differences in the levels of bioactive gibberellin (GA. Accordingly, there is now compelling evidence that the TCA cycle plays an important role in modulating the rate of flux from 2-OG to amino acid metabolism. Here we discuss recent advances in the biochemistry and molecular biology of 2-OG metabolism occurring in different biological systems indicating the importance of 2-OG and 2-OG dependent dioxygenases not only in glucosinolate, flavonoid and alkaloid metabolism but also in GA and amino acid metabolism. We additionally summarize recent findings regarding the impact of modification of 2-OG metabolism on biosynthetic pathways involving 2-ODDs.

  19. CHANGES IN THE CHARACTERISTICS OF ‘PRATA’ BANANA TREATED WITH CYTOKININ AND GIBBERELLIN

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    JULIANA DOMINGUES LIMA

    Full Text Available ABSTRACT Plant growth regulators can influence fruit yield and quality. This study aimed to evaluate the effect of cytokinin and gibberelin on the agronomic and physicochemical characteristics of banana fruits cv. ‘Prata’ (Musa spp. AAB, according to the formation period and position in the bunch. The experiment was conducted in a completely randomized 2 x 5 factorial design, two periods of bunch development (summer and winter, five treatments and ten replicates. To study the effect of position in the bunch, split plot was adopted, considering in the plot, 2 x 5 factorial and in subplots, hand 1, hand 4 and last hand. Treatments consisted of 2 pulverizations with water, 150 mg L-1 cytokinin, 200 mg L-1 of gibberellic acid, 100 mg L-1 of cytokinin plus 200 mg L-1 of gibberellic acid and 200 mg L-1 of cytokinin plus 200 mg L-1 of gibberellic acid, applied from the fourth to the last hand of the bunch. Cytokinin and gibberellin, alone or associated, regardless of formation period and position, did not affect the size and physicochemical characteristics of fruits, only delayed the bunch harvest.

  20. Exploring the response of rice (Oryza sativa) leaf to gibberellins: a proteomic strategy.

    Science.gov (United States)

    Wang, Xiaoqin; Han, Feng; Yang, Mingfeng; Yang, Pingfang; Shen, Shihua

    2013-07-01

    Gibberellins (GAs) are plant-specific hormones that play a central role in the regulation of growth and development with respect to environmental variability. Plants respond to GAs signal through various biochemical and physiological processes. To better understand the response for GA signal, we carried out a proteomic study in rice (Oryza sativa L. spp. japonica) leaf. Through two-dimensional gel electrophoresis (2-DE) and mass spectroscopy analysis, we identified 61 proteins as GA-responsive. These proteins were annotated in various biological functions, such as signal transduction and cell growth/division, photosynthesis and energy metabolism, protein stability and defense. Among these, photosynthetic proteins decreased while many catabolic proteins increased. In addition, GA up-regulated a variety of cell growth/division, protein stability and defense proteins such as cell division cycle protein 48, molecular chaperones, and catalases. This is the first report that cell division cycle protein 48 may be responsible for leaf expansion after leaf sensing GA signal. The results presented here provide new insight into the mechanism of rice leaf in response to GA signal.

  1. In vivo gibberellin biosynthesis in endosperm of Sechium edule Sw. seeds

    Energy Technology Data Exchange (ETDEWEB)

    Ceccarelli, N.; Lorenzi, R. (Universita degli Studi, Pisa (Italy))

    1990-07-01

    Biosynthesis of gibberellins (GAs) was studied in vivo in endosperms of Sechium edule Sw. Exogenous ent-({sup 14}C)kaurene was metabolized into four major products: GA{sub 12}, GA{sub 4}, GA{sub 7} and 16,17-dihydro-16-hydroxy-GA{sub 15} alcohol glucoside. Other minor metabolites were also observed including ent-kaurenol and ent-kaurenal. Conversion of ent-({sup 14}C)kaurene to ent-karuenol glucoside by endosperm cell-free preparations in the presence of UDPG was observed. However, the finding was not confirmed in in vivo studies and is probably artifactual. Overall evidence coming from the analysis of endogenous GAs and in vitro and in vivo biosynthetic studies are discussed in relation to the possible existence in the Sechium seeds of a different route, along with the known pathway, branching from ent-kaurene or ent-7-{alpha}-hydroxykaurenoic acid and this also leading to biologically active GAs.

  2. Phytochrome, Gibberellins, and Hypocotyl Growth (A Study Using the Cucumber (Cucumis sativus L.) long hypocotyl Mutant).

    Science.gov (United States)

    Lopez-Juez, E.; Kobayashi, M.; Sakurai, A.; Kamiya, Y.; Kendrick, R. E.

    1995-01-01

    The possible involvement of gibberellins (GAs) in the regulation of hypocotyl elongation by phytochrome was examined. Under white light the tall long hypocotyl (lh) cucumber (Cucumis sativus L.) mutant, deficient in a type B-like phytochrome, shows an increased "responsiveness" (defined as response capability) to applied GA4 (the main endogenous active GA) compared to the wild type. Supplementing far-red irradiation results in a similar increase in responsiveness in the wild type. Experiments involving application of the precursor GA9 and of an inhibitor of GA4 inactivation suggest that both the GA4 activation and inactivation steps are phytochrome independent. Endogenous GA levels of whole seedlings were analyzed by combined gas chromatography-mass spectrometry using deuterated internal standards. The levels of GA4 (and those of GA34, the inactivated GA4) were lower in the lh mutant under low-irradiance fluorescent light compared with the wild type, similar to wild type under higher irradiance light during the initial hypocotyl extension phase, and higher during the phase of sustained growth, in which extension involved an increase in the number of cells in the upper region. In all cases, growth of the lh mutant was more rapid than that of the wild type. It is proposed that GA4 and phytochrome control cell elongation primarily through separate mechanisms that interact at a step close to the terminal response. PMID:12228348

  3. Sugar Repression of a Gibberellin-Dependent Signaling Pathway in Barley Embryos.

    Science.gov (United States)

    Perata, P.; Matsukura, C.; Vernieri, P.; Yamaguchi, J.

    1997-01-01

    Increasing evidence shows that sugars can act as signals affecting plant metabolism and development. Some of the effects of sugars on plant growth and development suggest an interaction of sugar signals with hormonal regulation. We investigated the effects of sugars on the induction of [alpha]-amylase by gibberellic acid in barley embryos and aleurone layers. Our results show that sugar and hormonal signaling interact in the regulation of gibberellic acid-induced gene expression in barley grains. The induction of [alpha]-amylase by gibberellic acid in the aleurone layer is unaffected by the presence of sugars, but repression by carbohydrates is effective in the embryo. [alpha]-Amylase expression in the embryo is localized to the scutellar epithelium and is hormone and sugar modulated. The effects of glucose are independent from the effects of sugars on gibberellin biosynthesis. They are not due to an osmotic effect, they are independent of abscisic acid, and only hexokinase-phosphorylatable glucose analogs are able to trigger gene repression. Overall, the results suggest the existence of an interaction between the hormonal and metabolic regulation of [alpha]-amylase genes in barley grains. PMID:12237356

  4. GIBBERELLINS, FUNGICIDES AND STORAGE EFFECTS ON THE GERMINATION OF Genipa americana L. (RUBIACEAE SEEDS

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    Fábio de Almeida Vieira

    2006-06-01

    Full Text Available The aim of this paper was to verify the effect of different doses of gibberellic acid (GA3 (0, 250, 500, 750 and 1000 µg.L-1, of fungicides of the groups chemical benzimidazol (0, 25, 50 and 100 g.L-1 and ditiocarbamato (0, 1,25, 2,50 and 5,00 g.L-1 on seed germination. Viability of those seeds was evaluated through germination tests at 0, 15, 30 and 60 days. The experiment was carried out in greenhouse. The experimental design was fully randomized one, with five replicates per treatment. The traits evaluated were emergence and index of emergence speed. The treatment with GA3 didn't provide significant so much differences among the germination rates as well as for the emergence speed. It was verified that the use of the fungicides in smaller concentrations (25 g.L-1 of benzimidazol and 1,25 g.L-1 of ditiocarbamato promoted a better germination speed. The seeds of G. americana possess viability period relatively short, with germination absence 60 days period of storage, and it could be associated to the humidity tenors presented by the seeds in this period.

  5. Crystal structure of the compounds R8Ga3Co (R=Ce, Pr, Nd, Sm, Tb, Dy, Ho, Er, Tm)

    International Nuclear Information System (INIS)

    Grin', Yu.N.; Sichevich, O.M.; Gladyshevskij, R.E.; Yarmolyuk, Ya.P.

    1984-01-01

    The crystal structure of Pr 8 Ga 3 Co compounds is studied by the method of monocrystal (autodiffractometer, MoKsub(α)): space group P6 3 mc, a=10.489, c=6.910 A, Z=2. Coordination numbers of atoms are 11-14 for Pr, 11 for Ga, 7 for Co. The shortest interatomic distances are 3.365 for Pr-Pr, 3.047 for Pr-Ga, 2.75 A for Pr-Co. Pr 3 Ga 3 Co structure is akin to structures of R 2 In compounds (Ni 2 In type) and R 2 Ga (Cl 2 Pb type). Isostructural compounds form in systems of other rare earth metals with gallium and cobalt

  6. Luminescence and scintillation characteristics of (GdxY3-x)Al2Ga3O12:Ce (x = 1,2,3) single crystals

    Science.gov (United States)

    Chewpraditkul, Warut; Pattanaboonmee, Nakarin; Sakthong, Ongsa; Chewpraditkul, Weerapong; Szczesniak, Tomasz; Moszynski, Marek; Kamada, Kei; Yoshikawa, Akira; Nikl, Martin

    2018-02-01

    The luminescence and scintillation characteristics of Czochralski-grown (GdxY3-x)Al2Ga3O12:Ce (x = 1,2,3) single crystals are presented. With increasing Gd content in this garnet host, the 5d2 absorption band was blue-shifted while the 5d1 absorption and 5d1 → 4f emission bands were red-shifted due to an increase in the crystal field splitting of the 5d levels. In addition, the luminescence quenching temperature of the Ce3+emission and activation energy for thermal quenching decreased with increasing Gd content. The Gd3+ → Ce3+ energy transfer was evidenced by photoluminescence excitation spectra of Ce3+ emission. At 662 keV γ - rays, the light yield (LY) of 48,600 ph/MeV and energy resolution of 6.5% was measured for a Gd3Al2Ga3O12:Ce crystal. Scintillation decay measurements were performed using the time-correlated single photon counting technique. Superior time resolution of Gd3Al2Ga3O12:Ce is due to its high LY and fast scintillation response. The total mass attenuation coefficients at 60 and 662 keV γ - rays were also determined.

  7. Improvement of Orange II Photobleaching by Moderate Ga3+ Doping of Titania and Detrimental Effect of Structural Disorder on Ga Overloading

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    Václav Štengl

    2014-01-01

    Full Text Available Highly photoactive Ga3+-doped anatase modification of titania was prepared by homogeneous hydrolysis of aqueous solutions mixture of titanium oxo-sulphate TiOSO4 and gallium(III nitrate with urea. Incorporation of Ga3+ into the anatase lattice has a clear positive effect on the photocatalytic activity under UV and Vis light irradiation up to a certain extent of Ga. Ga3+ doping decreased the size of the crystallites, increased surface area, and affected texture of the samples. Higher amount of gallium leads to the formation of a nondiffractive phase, probably photocatalytically inactive. The titania sample with 2.18 wt.% Ge3+ had the highest activity during the photocatalysed degradation in the UV and visible light regions; the total bleaching of dye Orange II was achieved within 29 minutes. Ga concentration larger than 5% (up to 15% significantly inhibited the growth of the anatase crystal domains which formed the nondiffractive phase content and led to remarkable worsening of the photobleaching efficiency.

  8. Effect of Mg$^{2+}$ ions co-doping on timing performance and radiation tolerance of Cerium doped Gd$_{3}$Al$_{2}$Ga$_{3}$O$_{12}$ crystals

    CERN Document Server

    Lucchini, M.T.; Bohacek, P.; Gundacker, S.; Kamada, K.; Nikl, M.; Petrosyan, A.; Yoshikawa, A.; Auffray, E.

    2016-01-01

    Inorganic scintillators with high density and high light yield are of major interest for applications in medical imaging and high energy physics detectors. In this work, the optical and scintillation properties of Mg co-doped Ce:Gd3Al2Ga3O12 crystals, grown using Czochralski technique, have been investigated and compared with Ce:Gd3Al2Ga3O12 ones prepared with identical technology. Improvements in the timing performance of the Mg co-doped samples with respect to Ce:Gd3Al2Ga3O12 ones have been measured, namely a substantial shortening of the rise time and scintillation decay components and lower afterglow were achieved. In particular, a significantly better coincidence time resolution of 233 ps FWHM, being a fundamental parameter for TOF-PET devices, has been observed in Mg co-doped crystals. The samples have also shown a good radiation tolerance under high doses of γ-rays, making them suitable candidates for applications in harsh radiation environments, such as detectors at future collider experiments.

  9. Germinação de sementes de atemoia (Annona Cherimola Mill. x A. squamosa L. cv 'Gefner' submetidas a tratamentos com ácido Giberélico (GA3 e ethephon Germination of atemoya seeds (Annona Cherimola Mill. x A. squamosa L. cv 'Gefner' subjected to treatments with Gibberellic acid (GA3 and ethephon

    Directory of Open Access Journals (Sweden)

    Marcos Campos de Oliveira

    2010-06-01

    Full Text Available O objetivo deste trabalho foi estudar os efeitos do ácido giberélico (GA3, do ethephon e da interação de ambos os reguladores vegetais no processo germinativo de sementes de atemoia (Annona cherimola Mill. x A. squamosa L. , cultivar 'Gefner'. Empregou-se delineamento experimental inteiramente casualizado, em esquema fatorial 5², com os tratamentos constituídos pela combinação de cinco concentrações de GA3 (ácido giberélico e cinco concentrações de ethephon, resultando em 25 tratamentos, com quatro repetições de 25 sementes por parcela. As concentrações de GA3 empregadas foram: 0; 250; 500; 750 e 1.000 mg L-1 i.a.e de ethephon: 0; 25; 50; 75 e 100 mg L-1 i.a.. Os tratamentos com os reguladores vegetais foram aplicados na semente por imersão das mesmas nas soluções de GA3 e ethephon por período de 36 horas. As sementes foram semeadas em rolo de papel germitest e levadas à câmara de germinação onde permaneceram no escuro, com temperatura alternada entre 20ºC por 8 horas e 30ºC por 16 horas. As variáveis avaliadas foram: percentagem, tempo e índice de velocidade de germinação, percentagem de plântulas normais e percentagem de sementes dormentes. Existe interação da ação dos reguladores vegetais estudados no processo germinativo de sementes de atemoia, o que permite concluir que a percentagem de germinação de sementes de atemoia (Annona cherimola Mill. x A. squamosa L. cv 'Gefner' é aumentada com o emprego de 778 mg L-1 de GA3, enquanto a associação entre elevadas concentrações de GA3 e 75 a 100 mg L-1 de ethephon incrementam o índice de velocidade de germinação e a percentagem de plântulas normais.The aim of this work was to evaluate the effect of gibberellic acid (GA3 and ethephon, besides the interaction of both plant growth regulators, on the germinative process of atemoya seeds (Annona cherimola Mill. X A. squamosa L., cultivar 'Gefner'. Experimental design was completely randomized, in a 5

  10. ARABIDOPSIS THALIANA HOMEOBOX25 uncovers a role for Gibberellins in seed longevity.

    Science.gov (United States)

    Bueso, Eduardo; Muñoz-Bertomeu, Jesús; Campos, Francisco; Brunaud, Veronique; Martínez, Liliam; Sayas, Enric; Ballester, Patricia; Yenush, Lynne; Serrano, Ramón

    2014-02-01

    Seed longevity is crucial for agriculture and plant genetic diversity, but it is limited by cellular damage during storage. Seeds are protected against aging by cellular defenses and by structures such as the seed coat. We have screened an activation-tagging mutant collection of Arabidopsis (Arabidopsis thaliana) and selected four dominant mutants with improved seed longevity (isl1-1D to isl4-1D) under both natural and accelerated aging conditions. In the isl1-1D mutant, characterized in this work, overexpression of the transcription factor ARABIDOPSIS THALIANA HOMEOBOX25 (ATHB25; At5g65410) increases the expression of GIBBERELLIC ACID3-OXIDASE2, encoding a gibberellin (GA) biosynthetic enzyme, and the levels of GA1 and GA4 are higher (3.2- and 1.4-fold, respectively) in the mutant than in the wild type. The morphological and seed longevity phenotypes of the athb25-1D mutant were recapitulated in transgenic plants with moderate (4- to 6-fold) overexpression of ATHB25. Simultaneous knockdown of ATHB25, ATHB22, and ATHB31 expression decreases seed longevity, as does loss of ATHB25 and ATHB22 function in a double mutant line. Seeds from wild-type plants treated with GA and from a quintuple DELLA mutant (with constitutive GA signaling) are more tolerant to aging, providing additional evidence for a role of GA in seed longevity. A correlation was observed in several genotypes between seed longevity and mucilage formation at the seed surface, suggesting that GA may act by reinforcing the seed coat. This mechanism was supported by the observation of a maternal effect in reciprocal crosses between the wild type and the athb25-1D mutant.

  11. ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity1[C][W

    Science.gov (United States)

    Bueso, Eduardo; Muñoz-Bertomeu, Jesús; Campos, Francisco; Brunaud, Veronique; Martínez, Liliam; Sayas, Enric; Ballester, Patricia; Yenush, Lynne; Serrano, Ramón

    2014-01-01

    Seed longevity is crucial for agriculture and plant genetic diversity, but it is limited by cellular damage during storage. Seeds are protected against aging by cellular defenses and by structures such as the seed coat. We have screened an activation-tagging mutant collection of Arabidopsis (Arabidopsis thaliana) and selected four dominant mutants with improved seed longevity (isl1-1D to isl4-1D) under both natural and accelerated aging conditions. In the isl1-1D mutant, characterized in this work, overexpression of the transcription factor ARABIDOPSIS THALIANA HOMEOBOX25 (ATHB25; At5g65410) increases the expression of GIBBERELLIC ACID3-OXIDASE2, encoding a gibberellin (GA) biosynthetic enzyme, and the levels of GA1 and GA4 are higher (3.2- and 1.4-fold, respectively) in the mutant than in the wild type. The morphological and seed longevity phenotypes of the athb25-1D mutant were recapitulated in transgenic plants with moderate (4- to 6-fold) overexpression of ATHB25. Simultaneous knockdown of ATHB25, ATHB22, and ATHB31 expression decreases seed longevity, as does loss of ATHB25 and ATHB22 function in a double mutant line. Seeds from wild-type plants treated with GA and from a quintuple DELLA mutant (with constitutive GA signaling) are more tolerant to aging, providing additional evidence for a role of GA in seed longevity. A correlation was observed in several genotypes between seed longevity and mucilage formation at the seed surface, suggesting that GA may act by reinforcing the seed coat. This mechanism was supported by the observation of a maternal effect in reciprocal crosses between the wild type and the athb25-1D mutant. PMID:24335333

  12. Association genetics and transcriptome analysis reveal a gibberellin-responsive pathway involved in regulating photosynthesis.

    Science.gov (United States)

    Xie, Jianbo; Tian, Jiaxing; Du, Qingzhang; Chen, Jinhui; Li, Ying; Yang, Xiaohui; Li, Bailian; Zhang, Deqiang

    2016-05-01

    Gibberellins (GAs) regulate a wide range of important processes in plant growth and development, including photosynthesis. However, the mechanism by which GAs regulate photosynthesis remains to be understood. Here, we used multi-gene association to investigate the effect of genes in the GA-responsive pathway, as constructed by RNA sequencing, on photosynthesis, growth, and wood property traits, in a population of 435 Populus tomentosa By analyzing changes in the transcriptome following GA treatment, we identified many key photosynthetic genes, in agreement with the observed increase in measurements of photosynthesis. Regulatory motif enrichment analysis revealed that 37 differentially expressed genes related to photosynthesis shared two essential GA-related cis-regulatory elements, the GA response element and the pyrimidine box. Thus, we constructed a GA-responsive pathway consisting of 47 genes involved in regulating photosynthesis, including GID1, RGA, GID2, MYBGa, and 37 photosynthetic differentially expressed genes. Single nucleotide polymorphism (SNP)-based association analysis showed that 142 SNPs, representing 40 candidate genes in this pathway, were significantly associated with photosynthesis, growth, and wood property traits. Epistasis analysis uncovered interactions between 310 SNP-SNP pairs from 37 genes in this pathway, revealing possible genetic interactions. Moreover, a structural gene-gene matrix based on a time-course of transcript abundances provided a better understanding of the multi-gene pathway affecting photosynthesis. The results imply a functional role for these genes in mediating photosynthesis, growth, and wood properties, demonstrating the potential of combining transcriptome-based regulatory pathway construction and genetic association approaches to detect the complex genetic networks underlying quantitative traits. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights

  13. Efeitos do CPPU e GA3 no cultivo de uva-'Itália' na região do submédio São Francisco, nordeste do Brasil Effect of CPPU and GA3 in grapes 'Itália' in Submedium São Francisco River Valley region, northeast Brazil

    Directory of Open Access Journals (Sweden)

    CARLOS AUGUSTO MENEZES FEITOSA

    2002-08-01

    Full Text Available Na região do submédio do São Francisco, a uva-'Itália' destaca-se com 63,2% da área total plantada. Atualmente, é a principal variedade para exportação. O objetivo principal deste trabalho foi avaliar o efeito das doses do CPPU (forchlorfenuron e GA3, no aumento do tamanho da baga, que foram aplicadas por meio de pulverização dirigida sobre os cachos durante a fase de pegamento dos frutos, quando as bagas haviam atingido, aproximadamente, 8 mm de diâmetro. Este experimento foi conduzido na Fazenda Cooperyama, no município de Juazeiro-BA. O delineamento experimental foi o inteiramente casualizado, com oito tratamentos e três repetições, avaliando-se 15 cachos por tratamento com as seguintes doses: 1- Testemunha absoluta; 2- GA3 20 mg/l;3- GA3 20 mg/l+ CPPU 3 mg/l; 4- GA3 20 mg/l + CPPU 5 mg/l; 5- GA3 20 mg/l + CPPU 10 mg/l; 6- CPPU 3 mg/l; 7- CPPU 5 mg/l; 8- CPPU 10 mg/l.O melhor resultado obtido no crescimento da baga deu-se com a aplicação do CPPU 10 mg/l. Este tratamento diferiu significativamente da testemunha e da aplicação convencional com GA3 20 mg/l, aumentando 8% e 4,6% o comprimento da baga, 13,6% e 7,3% sua largura, e o peso de baga em 32% e 16,3%, respectivamente. Nos tratamentos com CPPU aplicado isoladamente e/ou associado com GA3, a colheita foi retardada em oito dias. Não se verificou diferença significativa para os teores de sólidos solúveis; no entanto, foi constatado que a acidez titulável obteve valores mais elevados na testemunha e no tratamento com GA3, aplicando 20 mg/l. Com relação ao peso do engaço, não foi verificada diferença estatística entre os tratamentos.The Itália grape cultivar participates with 63,2% of the total growing area in Submedium São Francisco River Valley it's the main variety for exportation. The main objective in this work was to evaluate the effect of CPPU (forchlorfenuron and GA3 doses on the berry size increase. The products were applied by spraying them on the

  14. [Bi3GaS5]2[Ga3Cl10]2[GaCl4]2·S8 containing heterocubane-type [Bi3GaS5]2+, star-shaped [Ga3Cl10]-, monomeric [GaCl4]- and crown-like S8.

    Science.gov (United States)

    Freudenmann, Dominic; Feldmann, Claus

    2011-01-14

    By reaction of elemental bismuth, sulfur, bismuth(III) chloride and gallium(III) chloride in the ionic liquid (BMIm)Cl (BMIm: 1-butyl-3-methylimidazolium), [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is obtained as red transparent crystals. According to X-ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and is composed of heterocubane-type [Bi(3)GaS(5)](2+) cations, trimeric star-shaped [Ga(3)Cl(10)](-) anions with three (GaCl(4)) tetrahedra sharing a single central chlorine atom, monomeric [GaCl(4)](-) tetrahedra and neutral, crown-shaped S(8)-rings. Here, the heterocubane [Bi(3)GaS(5)](2+) as well as the star-shaped [Ga(3)Cl(10)](-) are observed as building units for the first time. [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is further characterized by X-ray powder diffraction as well as by thermogravimetry/differential thermal analysis.

  15. Effects of chilling and ABA on [3H]gibberellin A4 metabolism in somatic embryos of grape (Vitis vinifera L. x V. rupestris Scheele)

    International Nuclear Information System (INIS)

    Pearce, D.; Pharis, R.P.; Rajasekaran, K.; Mullins, M.G.

    1987-01-01

    Previous work has indicated that changes in gibberellin (GA) metabolism may be involved in chilling-induced release from dormancy in somatic embryos of grape (Vitis vinifera L. x V. rupestris Scheele). The authors have chilled somatic embryos of grape for 2, 4, or 8 weeks, then incubated them with [ 3 H]GA 4 (of high specific activity, 4.81 x 10 19 becquerel per millimole) for 48 hours at 26 0 C. Chilling had little effect on the total amount of free [ 3 H]GA-like metabolites formed during incubation at 26 0 C, but did change the relative proportions of individual metabolites. The amount of highly water-soluble [ 3 H] metabolites formed at 26 0 C decreased in embryos chilled for 4 or 8 weeks. The concentration of endogeneous GA precursors (e.g., GA 12 aldehyde-, kaurene, and kaurenoic acid-like substances) increased in embryos chilled for 4 or 8 weeks. Treatment with abscisic acid (ABA) (known to inhibit germination in grape embryos) concurrent with [ 3 H]GA 4 treatment at 26 0 C, reduced the uptake of [ 3 H] GA 4 but had little effect on the qualitative spectrum of metabolites. However, in the embryos chilled for 8 weeks and then treated with ABA for 48 hours at 26 0 C, there was a higher concentration of GA precursors than in untreated control embryos. Chilled embryos thus have an enhanced potential for an increase in free GAs through synthesis from increased amounts of GA precursors, or through a reduced ability to form highly water-soluble GA metabolites (i.e., GA conjugates or polyhydroxylated free GAs)

  16. Overexpression of AtDREB1A causes a severe dwarf phenotype by decreasing endogenous gibberellin levels in soybean [Glycine max (L. Merr].

    Directory of Open Access Journals (Sweden)

    Haicui Suo

    Full Text Available Gibberellic acids (GAs are plant hormones that play fundamental roles in plant growth and developmental processes. Previous studies have demonstrated that three key enzymes of GA20ox, GA3ox, and GA2ox are involved in GA biosynthesis. In this study, the Arabidopsis DREB1A gene driven by the CaMV 35S promoter was introduced into soybean plants by Agrobacterium- mediated transformation. The results showed that the transgenic soybean plants exhibited a typical phenotype of GA-deficient mutants, such as severe dwarfism, small and dark-green leaves, and late flowering compared to those of the non-transgenic plants. The dwarfism phenotype was rescued by the application of exogenous GA(3 once a week for three weeks with the concentrations of 144 µM or three times in one week with the concentrations of 60 µM. Quantitative RT-PCR analysis revealed that the transcription levels of the GA synthase genes were higher in the transgenic soybean plants than those in controls, whereas GA-deactivated genes except GmGA2ox4 showed lower levels of expression. The transcript level of GmGA2ox4 encoding the only deactivation enzyme using C(20-GAs as the substrates in soybean was dramatically enhanced in transgenic plants compared to that of wide type. Furthermore, the contents of endogenous bioactive GAs were significantly decreased in transgenic plants than those of wide type. The results suggested that AtDREB1A could cause dwarfism mediated by GA biosynthesis pathway in soybean.

  17. Overexpression of AtDREB1A causes a severe dwarf phenotype by decreasing endogenous gibberellin levels in soybean [Glycine max (L.) Merr].

    Science.gov (United States)

    Suo, Haicui; Ma, Qibin; Ye, Kaixin; Yang, Cunyi; Tang, Yujuan; Hao, Juan; Zhang, Zhanyuan J; Chen, Mingluan; Feng, Yuqi; Nian, Hai

    2012-01-01

    Gibberellic acids (GAs) are plant hormones that play fundamental roles in plant growth and developmental processes. Previous studies have demonstrated that three key enzymes of GA20ox, GA3ox, and GA2ox are involved in GA biosynthesis. In this study, the Arabidopsis DREB1A gene driven by the CaMV 35S promoter was introduced into soybean plants by Agrobacterium- mediated transformation. The results showed that the transgenic soybean plants exhibited a typical phenotype of GA-deficient mutants, such as severe dwarfism, small and dark-green leaves, and late flowering compared to those of the non-transgenic plants. The dwarfism phenotype was rescued by the application of exogenous GA(3) once a week for three weeks with the concentrations of 144 µM or three times in one week with the concentrations of 60 µM. Quantitative RT-PCR analysis revealed that the transcription levels of the GA synthase genes were higher in the transgenic soybean plants than those in controls, whereas GA-deactivated genes except GmGA2ox4 showed lower levels of expression. The transcript level of GmGA2ox4 encoding the only deactivation enzyme using C(20)-GAs as the substrates in soybean was dramatically enhanced in transgenic plants compared to that of wide type. Furthermore, the contents of endogenous bioactive GAs were significantly decreased in transgenic plants than those of wide type. The results suggested that AtDREB1A could cause dwarfism mediated by GA biosynthesis pathway in soybean.

  18. Plant-specific Histone Deacetylases HDT½ Regulate GIBBERELLIN 2-OXIDASE 2 Expression to Control Arabidopsis Root Meristem Cell Number

    KAUST Repository

    Li, Huchen

    2017-08-31

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription factors and chromatin-remodelling factors have been implicated in regulating the switch from stem cells to transit-amplifying cells. Here we show that two Arabidopsis thaliana paralogs encoding plant-specific histone deacetylases, HDT1 and HDT2, regulate a second switch from transit-amplifying cells to expanding cells. Knockdown of HDT½ (hdt1,2i) results in an earlier switch and causes a reduced RM cell number. Our data show that HDT½ negatively regulate the acetylation level of the C19-GIBBERELLIN 2-OXIDASE 2 (GA2ox2) locus and repress the expression of GA2ox2 in the RM and elongation zone. Overexpression of GA2ox2 in the RM phenocopies the hdt1,2i phenotype. Conversely, knockout of GA2ox2 partially rescues the root growth defect of hdt1,2i. These results suggest that by repressing the expression of GA2ox2, HDT½ likely fine-tune gibberellin metabolism and they are crucial for regulating the switch from cell division to expansion to determine RM cell number. We propose that HDT½ function as part of a mechanism that modulates root growth in response to environmental factors.

  19. Transcriptional mechanisms associated with seed dormancy and dormancy loss in the gibberellin-insensitive sly1-2 mutant of Arabidopsis thaliana

    Science.gov (United States)

    While widespread transcriptome changes have been previously observed with seed dormancy loss, this study specifically characterized transcriptional changes associated with the increased seed dormancy and dormancy loss of the gibberellin (GA) hormone-insensitive sleepy1-2 (sly1-2) mutant. The SLY1 g...

  20. Identification and localization of gibberellins in maturing seeds of the cucurbit Sechium edule, and a comparison between this cucurbit and the legume Phaseolus coccineus.

    Science.gov (United States)

    Albone, K S; Gaskin, P; Macmillan, J; Sponsel, V M

    1984-12-01

    Twenty known gibberellins (GAs) have been identified by combined capillary gas chromatography-mass spectrometry in extracts from less than 10 g fresh weight of maturing seeds of the cucurbit Sechium edule Sw. The GAs are predominantly 3- and-or 13-hydroxylated. This is the first reported identification of non-conjugated 13-hydroxylated GAs in a cucurbit. Gibberellin A8 and gibberellin A8-catabolite are the major GAs in terms of quantity and are largely accumulated in the testa. The catabolites of 2β-hydroxylated GAs are α,β-unsaturated ketones which no longer possess of a γ-lactone. They were hitherto known only in legumes. The presence of GA8-catabolite as a major component of Sechium seeds indicates that the distribution of these GA-catabolites may be more widespread than previously envisaged. The localization of known GAs in maturing seeds of the legume Phaseolus coccineus L. was found to resemble closely that in Sechium. Gibberellin A8, a putative conjugate of GA8 and GA8-catabolite are accumulated in the testa. The localization in the testa of end-products of the GA-biosynthetic pathway, which was first observed in maturing seeds of Pisum sativum, and is now described in Phaseolus and Sechium, may be a general feature of seed development.

  1. Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

    Science.gov (United States)

    2011-01-01

    Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA) and abscisic acid (ABA) are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up-regulated by both GA and seed

  2. Growth of self-textured Ga3+-substituted Li7La3Zr2O12 ceramics by solid state reaction and their significant enhancement in ionic conductivity

    Science.gov (United States)

    Qin, Shiying; Zhu, Xiaohong; Jiang, Yue; Ling, Ming'en; Hu, Zhiwei; Zhu, Jiliang

    2018-03-01

    A highly self-textured Ga2O3-substituted Li7La3Zr2O12 (LLZO-Ga) solid electrolyte with a nominal composition of Li6.55Ga0.15La3Zr2O12 is obtained by a simple and low-cost solid-state reaction technique, requiring no seed crystals to achieve grain orientation. The as-prepared self-textured LLZO-Ga shows a strong (420) preferred orientation with a high Lotgering factor of 0.91. Coherently, a terrace-shaped microstructure consisting of many parallel layers, indicating a two-dimensional-like growth mode, is clearly observed in the self-textured sample. As a result, the highly self-textured garnet-type lithium-ion conducting solid electrolyte of LLZO-Ga exhibits an extremely high ionic conductivity, reaching a state-of-the-art level of 2.06 × 10-3 S cm-1 at room temperature (25 °C) and thus shedding light on an important strategy for improving the structure and ionic conductivity of solid electrolytes.

  3. Influence of Cytokinins in Combination with GA3 on Shoot Multiplication and Elongation of Tea Clone Iran 100 (Camellia sinensis (L.) O. Kuntze)

    Science.gov (United States)

    Gonbad, Reza Azadi; Mohamad, Rosfarizan

    2014-01-01

    The use of in vitro culture has been accepted as an efficient technique for clonal propagation of many woody plants. In the present research, we report the results of a number of experiments aimed at optimizing micropropagation protocol for tea (Camellia sinensis (L.) O. Kuntze) (clone Iran 100) using nodal segments as the explant. The effect of different combinations and concentrations of plant growth regulators (PGR) (BAP, TDZ, GA3) on shoot multiplication and elongation was assessed. The influence of exposure to IBA in liquid form prior to transfer to solid media on rooting of tea microshoots was investigated. The results of this study showed that the best treatment for nodal segment multiplication in terms of the number of shoot per explant and shoot elongation was obtained using 3 mg/L BAP in combination with 0.5 mg/L GA3. TDZ was found to be inappropriate for multiplication of tea clone Iran 100 as it resulted in hyperhydricity especially at concentrations higher than 0.05 mg/L. Healthy shoots treated with 300 mg/L IBA for 30 min followed by transfer to 1/2 strength MS medium devoid of PGR resulted in 72.3% of shoots producing roots and upon transferring them to acclimatization chamber 65% survival was obtained prior to field transfer. PMID:24605069

  4. Gibberellin secreting rhizobacterium, Pseudomonas putida H-2-3 modulates the hormonal and stress physiology of soybean to improve the plant growth under saline and drought conditions.

    Science.gov (United States)

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Khan, Abdul Latif; Kim, Min-Ji; Park, Jae-Man; Kim, Bo-Ra; Shin, Dong-Hyun; Lee, In-Jung

    2014-11-01

    The physiological changes in tolerant soybean plants under salt and drought stress conditions with Pseudomonas putida H-2-3 were investigated. A bacterial isolate H-2-3 was isolated from soil and identified as Pseudomonas putida H-2-3 by 16S rDNA sequences. The treatment of P. putida H-2-3 significantly increased the length, fresh and dry weight of shoot and chlorophyll content in gibberellins (GAs) deficient mutant Waito-c rice seedlings over the control, it might be the presence of GA1, GA4, GA9 and GA20. The soybean plant growth was retarded in salt (120 mM sodium chloride) and drought (15% polyethylene glycol) stress conditions at 10 days treatments, while P. putida H-2-3 effectively enhanced the shoot length and fresh weight of plants suffered at salt and drought stress. The chlorophyll content was lower in abiotic stress conditions and bacterial inoculant P. putida H-2-3 mitigated the stress effects by an evidence of higher quantity of chlorophyll content in plants exposed to salt and drought. The stress hormonal analysis revealed that individual treatment of P. putida H-2-3, salt and drought significantly enhanced the abscisic acid and salicylic acid content than their control. P. putida H-2-3 applied to salt and drought stressed plants showed a lower level of abscisic acid and salicylic acid and a higher level of jasmonic acid content. Under stress condition induced by salt and drought in plants expressed higher level of total polyphenol, superoxide dismutase and radical scavenging activity and no significant changes in flavonoids. The bio-inoculant, P. putida H-2-3 modulated those antioxidants by declining superoxide dismutase, flavonoids and radical scavenging activity. P. putida H-2-3 induced tolerance against abiotic stress was confirmed by a reduction of Na content in abiotic stressed plants. The results suggest that P. putida H-2-3 application reprograms the chlorophyll, stress hormones and antioxidants expression in abiotic stress affected

  5. Luminescence rise time in self-activated PbWO4 and Ce-doped Gd3Al2Ga3O12 scintillation crystals

    CERN Document Server

    E. Auffray; A. Borisevich; V. Gulbinas; A. Fedorov; M. Korjik; M.T. Lucchini; V. Mechinsky; S. Nargelas; E. Songaila; G. Tamulaitis; A. Vaitkevičius; S. Zazubovich

    2016-01-01

    The time resolution of scintillation detectors of ionizing radiation is one of the key parameters sought for in the current and future high-energy physics experiments. This study is encouraged by the necessity to find novel detection methods enabling a sub-10-ps time resolution in scintillation detectors and is focused on the exploitation of fast luminescence rise front. Time-resolved photoluminescence (PL) spectroscopy and thermally stimulated luminescence techniques have been used to study two promising scintillators: self-activated lead tungstate (PWO, PbWO4) and Ce-doped gadolinium aluminum gallium garnet (GAGG, Gd3Al2Ga3O12). A sub-picosecond PL rise time is observed in PWO, while longer processes in the PL response in GAGG:Ce are detected and studied. The mechanisms responsible for the PL rise time in self-activated and doped scintillators are under discussion.

  6. Effects of GA3, BA, Thiamine and Ascorbic Acid on Some Morphological and Biochemical Characteristics of Periwinkle (Catharanthus roseus L.

    Directory of Open Access Journals (Sweden)

    F. Baniasadi

    2016-07-01

    . All growth promoter substances increased flower diameter. Combined application of BAwith gibberellic acid had more influence on this parameter than other treatments, and increase flower diameter about 25%. Ascorbic acid plays an important role in cell division, plasma membrane, proton pumps and enlargement cell. According to the theory of acidic growth, ascorbic acid weakens cell wall and increases cell enlargement. Among the applied treatments combination of banzyladenine, thiamine and ascorbic acid increased the number of lateral branches to 100%. Results showed that GA in all concentrations and combinations used in this experiment increased lateral branches length. Several reports in plants such as croton, hibiscus and pot marigold indicated that BA can increase the number of branches per plant. Therefore, BA is used to enhance branching and to reduce the total height of the plants. The highest fresh and dry weight were observed in plants treated with the combinations of BA, thiamine and ascorbic acid. Thiamine increased chlorophyll a content more than other substances. There was no significant difference between thiamine or thiamine combined with ascorbic acid treatment on chlorophyll b content. Thiamine in combinations with all the other treatments significantly improved carotenoids content compared to control. Chlorophyll plays a key role in plants for the absorption and utilization of light energy which used in photosynthesis. Therefore, effects of PGRs on chlorophyll biosynthesis or degradation influence directly on photosynthesis. Thiamine was reported that in some plants assist resynthesize of chlorophyll in plant without chlorophyll and increased growth and yield eventually. All the treatments significantly increased reducing sugar. Although all of the substances improved the amount of reducing sugar, the role of thiamine was more dramatic compared to other treatments. The greatest amount of reducing sugar 85.3 mg. g-1 fresh weight was observed in the

  7. Myrigalone A Inhibits Lepidium sativum Seed Germination by Interference with Gibberellin Metabolism and Apoplastic Superoxide Production Required for Embryo Extension Growth and Endosperm Rupture

    Czech Academy of Sciences Publication Activity Database

    Oracz, K.; Voegele, A.; Tarkowská, Danuše; Jacquemoud, D.; Turečková, Veronika; Urbanová, Terezie; Strnad, Miroslav; Sliwinska, E.; Leubner-Metzger, G.

    2012-01-01

    Roč. 53, č. 1 (2012), s. 81-95 ISSN 0032-0781 R&D Projects: GA AV ČR KAN200380801; GA MŠk ED0007/01/01; GA ČR GD522/08/H003 Keywords : Embryo cell extension growth * Endoreduplication * Endosperm rupture * Gibberellin metabolism * Lepidium sativum * Myrica gale * Phytotoxicity * Reactive oxygen species Subject RIV: EF - Botanics Impact factor: 4.134, year: 2012

  8. Gibberellin-like effects of KAR1 on dormancy release of Avena fatua caryopses include participation of non-enzymatic antioxidants and cell cycle activation in embryos

    OpenAIRE

    Cembrowska-Lech, Danuta; K?pczy?ski, Jan

    2015-01-01

    Main conclusion The induction of dormancy release and germination of Avena fatua caryopses by KAR 1 involves ABA degradation to phaseic acid. Both, KAR 1 and GA 3 , control the AsA?GSH cycle, DNA replication and accumulation of ?-tubulin in embryos before caryopses germination. Abstract Avena fatua caryopses cannot germinate in darkness at 20??C because of dormancy, but karrikinolide-1 (KAR1), a compound in plant-derived smoke, and gibberellic acid (GA3) induced an almost complete germination...

  9. Carposeminal biometrics and germination of Lafoensia pacari A. St. Hil. (Lythraceae exposed to different concentrations of GA3Morfobiometria carpo-seminal e germinação de Lafoensia pacari A. St. Hil. (Lythraceae exposta a diferentes concentrações de GA3

    Directory of Open Access Journals (Sweden)

    Marisol Ragonha Fernandes

    2012-12-01

    Full Text Available Growth regulators improve seedling performance, accelerating the emergence rate and expanding the physiologic potential of the seeds even under adverse conditions. The aims of this study was carposeminal biometrics and evaluate the influence of GA3 at different concentrations, in overcoming seed dormancy Lafoensia pacari A. St. Hil., a tree species of savanna and medicinal interest. Biometrics has been used for 100 fruits and 100 seeds, measuring the length, fruit diameter and the operculum. The seeds were characterized by the average number per fruit, weight of 1000 seeds, besides the length, width and thickness, also made to the embryo. The treatments were: distilled water and GA3 at 5, 10 and 20 mg.L-1, added to four sets of 100 seeds each. The dry seeds on paper towels were placed in groups of 25 units in four Petri dishes with filter paper and 10 mL of distilled water, kept in an incubator B.O.D. at 25 ° C and white fluorescent light ?mol.m-2.s-1. The data were used to calculate the Germination Percentage (G%, Germination Speed Index (GSI and Mean Germination Time (TM, and the results submitted to linear regression analysis. The carposeminal biometrics obtained shows the relation of the fruit and seeds with the dispersion autochory/anemocoric and can serve as a tool for specific differentiation. The increasing concentrations of GA3 positively influenced the Percentage and Germination Speed Index and negatively Mean Time Germination.Reguladores de crescimento melhoram o desempenho das plântulas, acelerando a velocidade de emergência e ampliando o potencial fisiológico das sementes mesmo em condições adversas. O objetivo deste trabalho foi realizar a biometria carposeminal e avaliar a influência do GA3, em diferentes concentrações, na superação de dormência de sementes de Lafoensia pacari A. St. Hil., uma planta arbórea do cerrado e de interesse medicinal. Para a biometria foram utilizados 100 frutos e 100 sementes, nos quais

  10. Aplicação de ácido giberélico (GA3 em précolheita de tangerina ‘Poncã’ (Citrus reticulata blanco = Application of Gibberelic acid (GA3 on preharvest of ‘Ponkan’ mandarin (Citrus reticulata Blanco fruit

    Directory of Open Access Journals (Sweden)

    Júnior Cesar Modesto

    2006-01-01

    Full Text Available O experimento foi instalado em pomar comercial de tangerineira ‘Poncã’ (Citrus reticulata Blanco, enxertadas sobre tangerineira ‘Cleópatra’ (Citrus reshni Hort. ex Tan., em Pratânia, Estado de S��o Paulo, Brasil. Adotouse o delineamento experimental em blocoscasualizados com 4 repetições. Os tratamentos empregados foram: 0 (controle, 5, 10, 15 e 20 mg L1 de ácido giberélico (GA3. A aplicação dos tratamentos foi realizada com atomizador tratorizado. Na mudança de coloração dos frutos, utilizaramse 5,9 litros de solução por planta, com adição de 0,03% de surfatante não iônico com 25% de Alquil fenol poliglicoléter. As análises da qualidade dos frutos foram realizadas aos 13, 45, 75 e 111 dias após a aplicação dos tratamentos (DAT. Não se verificou influência da aplicação de GA3 na massa fresca dos frutos, no conteúdo de sólidos solúveis totais, na acidez total titulável e “ratio”. No entanto foi observado atraso na colheita de frutos, induzido pelo efeito fisiológico do ácido giberélico. The experiment was carried out in a commercial orchard of ‘Ponkan’ mandarin (Citrus reticulata Blanco, grafted on ‘Cleopatra’ mandarin (Citrus reshni Hort. ex Tan., in Pratânia, state of São Paulo, Brazil. The utilized experimental design was composed of randomized blocks of four replications. The treatments consisted of: 0 (control,5, 10, 15 and 20 mg L1 of Gibberellic acid (GA3. Atomizer equipment was utilized for the application of the treatments. Each plant received 5.9 liters of solution, in which 0.03% of nonionic surfactant with 25% of alkylphenol ethoxylate was added, in order to change fruit coloration. The analyses of fruit quality were developed on the 13th, 45th, 75th and 111th days after the application of the treatments (DAT. Results showed that the application of GA3 did not affect fruit fresh mass, total soluble solids content, total titulable acidity and ratio. However, a delay in fruit

  11. Apports spontanés en acides gras oméga 3 chez des diabétiques de type 2 tunisiens

    Directory of Open Access Journals (Sweden)

    Jamoussi Henda

    2014-09-01

    Full Text Available Il est admis à l’unanimité que les acides gras oméga 3 ont de multiples bénéfices pour la santé et plus précisément des effets protecteurs contre les maladies cardiovasculaires et neurodégénératives. L’objectif de ce travail était d’estimer les apports spontanés en acides alphalinolénique (ALA, docosahexaénoïque (DHA, éicosapentaénoïque (EPA et linoléique (LA. Cette étude d’observation a été réalisée auprès de 42 diabétiques de type 2 (21 hommes et 21 femmes âgés de 30 à 75 ans. L’estimation des apports en acides gras a été réalisée en utilisant la méthode d’enregistrement sur sept jours. Les résultats ont montré que l’apport moyen en ALA était de 0,99 ± 0,40 g/j soit 0,42 ± 0,13 % de l’apport énergétique total (AET. Aucun de nos patients n’avait un apport suffisant en ALA. Les apports quotidiens moyens en DHA et en EPA étaient respectivement de 90,0 ± 85 mg/j et de 83,5 ± 80 mg/j. Quant à la contribution des aliments aux apports en EPA et en DHA, les poissons et les fruits de mer représentaient la part la plus importante (57 % de ces deux acides gras. Nos résultats appellent à renforcer l’éducation nutritionnelle des diabétiques afin d’augmenter les apports en acides gras oméga 3 et d’assurer un rapport LA/ALA optimal qui contribuerait à la prévention des maladies cardiovasculaires.

  12. Mapping of a Cellulose-Deficient Mutant Named dwarf1-1 in Sorghum bicolor to the Green Revolution Gene gibberellin20-oxidase Reveals a Positive Regulatory Association between Gibberellin and Cellulose Biosynthesis.

    Science.gov (United States)

    Petti, Carloalberto; Hirano, Ko; Stork, Jozsef; DeBolt, Seth

    2015-09-01

    Here, we show a mechanism for expansion regulation through mutations in the green revolution gene gibberellin20 (GA20)-oxidase and show that GAs control biosynthesis of the plants main structural polymer cellulose. Within a 12,000 mutagenized Sorghum bicolor plant population, we identified a single cellulose-deficient and male gametophyte-dysfunctional mutant named dwarf1-1 (dwf1-1). Through the Sorghum propinquum male/dwf1-1 female F2 population, we mapped dwf1-1 to a frameshift in GA20-oxidase. Assessment of GAs in dwf1-1 revealed ablation of GA. GA ablation was antagonistic to the expression of three specific cellulose synthase genes resulting in cellulose deficiency and growth dwarfism, which were complemented by exogenous bioactive gibberellic acid application. Using quantitative polymerase chain reaction, we found that GA was positively regulating the expression of a subset of specific cellulose synthase genes. To cross reference data from our mapped Sorghum sp. allele with another monocotyledonous plant, a series of rice (Oryza sativa) mutants involved in GA biosynthesis and signaling were isolated, and these too displayed cellulose deficit. Taken together, data support a model whereby suppressed expansion in green revolution GA genes involves regulation of cellulose biosynthesis. © 2015 American Society of Plant Biologists. All Rights Reserved.

  13. Tunable Photoluminescent Core/Shell Cu(+)-Doped ZnSe/ZnS Quantum Dots Codoped with Al(3+), Ga(3+), or In(3+).

    Science.gov (United States)

    Cooper, Jason K; Gul, Sheraz; Lindley, Sarah A; Yano, Junko; Zhang, Jin Z

    2015-05-13

    Semiconductor quantum dots (QDs) with stable, oxidation resistant, and tunable photoluminescence (PL) are highly desired for various applications including solid-state lighting and biological labeling. However, many current systems for visible light emission involve the use of toxic Cd. Here, we report the synthesis and characterization of a series of codoped core/shell ZnSe/ZnS QDs with tunable PL maxima spanning 430-570 nm (average full width at half-maximum of 80 nm) and broad emission extending to 700 nm, through the use of Cu(+) as the primary dopant and trivalent cations (Al(3+), Ga(3+), and In(3+)) as codopants. Furthermore, we developed a unique thiol-based bidentate ligand that significantly improved PL intensity, long-term stability, and resilience to postsynthetic processing. Through comprehensive experimental and computational studies based on steady-state and time-resolved spectroscopy, electron microscopy, and density functional theory (DFT), we show that the tunable PL of this system is the result of energy level modification to donor and/or acceptor recombination pathways. By incorporating these findings with local structure information obtained from extended X-ray absorption fine structure (EXAFS) studies, we generate a complete energetic model accounting for the photophysical processes in these unique QDs. With the understanding of optical, structural, and electronic properties we gain in this study, this successful codoping strategy may be applied to other QD or related systems to tune the optical properties of semiconductors while maintaining low toxicity.

  14. Effect of codoping on scintillation and optical properties of a Ce-doped Gd3Ga3Al2O12 scintillator

    International Nuclear Information System (INIS)

    Tyagi, Mohit; Meng, Fang; Koschan, Merry; Donnald, Samuel B; Rothfuss, Harold; Melcher, Charles L

    2013-01-01

    Single crystals of Gd 3 Ga 3 Al 2 O 12  : Ce with different codopants were successfully grown using the Czochralski technique. Optical and scintillation properties of these codoped crystals were studied in detail including absorption, photoluminescence excitation and emission, decay time and thermoluminescence. This study revealed that while boron codoping improves the scintillation light output and energy resolution and decreases self-absorption in these crystals, calcium codoping affects their properties in the opposite manner. In addition to antisite defects, the effect of room temperature trap centres on the sensitivity of these crystals to light exposure is also reported for the first time. Light sensitivity was also found to be affected with the incorporation of codopants in the lattice. The effect of annealing in oxidizing and reducing atmospheres on the scintillation and optical properties of differently codoped crystals was also investigated in detail in order to better understand the defect structure of these crystals. All these measurements together are used to explain the effect of codoping on the crystal field and defect structure of these crystals. (paper)

  15. Cloning and molecular analyses of a gibberellin 20-oxidase gene expressed specifically in developing seeds of watermelon.

    Science.gov (United States)

    Kang, H G; Jun, S H; Kim, J; Kawaide, H; Kamiya, Y; An, G

    1999-10-01

    To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA(12) at C-20 to the C(19) compound GA(9), a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the beta-glucuronidase (GUS) gene. In a transient expression system, beta-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds.

  16. Cloning and Molecular Analyses of a Gibberellin 20-Oxidase Gene Expressed Specifically in Developing Seeds of Watermelon1

    Science.gov (United States)

    Kang, Hong-Gyu; Jun, Sung-Hoon; Kim, Junyul; Kawaide, Hiroshi; Kamiya, Yuji; An, Gynheung

    1999-01-01

    To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA12 at C-20 to the C19 compound GA9, a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the β-glucuronidase (GUS) gene. In a transient expression system, β-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds. PMID:10517828

  17. Silencing of the gibberellin receptor homolog, CsGID1a, affects locule formation in cucumber (Cucumis sativus) fruit.

    Science.gov (United States)

    Liu, Bin; Liu, Xingwang; Yang, Sen; Chen, Chunhua; Xue, Shudan; Cai, Yanling; Wang, Dandan; Yin, Shuai; Gai, Xinshuang; Ren, Huazhong

    2016-04-01

    Gibberellins are phytohormones with many roles, including the regulation of fruit development. However, little is known about the relationship between GA perception and fleshy fruit ontogeny, and particularly locule formation. We characterized the expression of cucumber (Cucumis sativus) GA receptor gene (CsGID1a) using quantitative real-time PCR, in situ hybridization and a promoter::β-glucuronidase (GUS) assay. CsGID1a-RNAi cucumber fruits were observed by dissecting microscope, scanning electron microscopy and transmission electron microscopy. Finally, genome-wide gene expression in young fruits from a control and the RNAi line was compared using a digital gene expression (DGE) analysis approach. The expression pattern of CsGID1a was found to be closely correlated with fruit locule formation, and silencing CsGID1a in cucumber resulted in fruits with abnormal carpels and locules. Overexpression of CsGID1a in the Arabidopsis thaliana double mutant (gid1a gid1c) resulted in 'cucumber locule-like' fruits. The DGE analysis suggested that expression of genes related to auxin synthesis and transport, as well as the cell cycle, was altered in CsGID1a-RNAi fruits, a result that was supported by comparing the auxin content and cellular structures of the control and transgenic fruits. This study demonstrates a previously uncharacterized GA signaling pathway that is essential for cucumber fruit locule formation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. Metabolism of Tritiated Gibberellin A9 by Shoots of Dark-grown Dwarf Pea, cv. Meteor 1

    Science.gov (United States)

    Railton, Ian D.; Durley, Richard C.; Pharis, Richard P.

    1974-01-01

    Tritium-labeled gibberellin A9 (3H-GA9) was metabolized by etiolated shoots of dwarf pea (Pisum sativum cv. Meteor) to GA20, GA10, 2,3-dihydro-GA31, and a number of highly polar, acidic GA-like substances. Identifications were made by gasliquid radiochromatography and combined gas chromatography-mass spectrometry. Kinetic studies showed that GA30 and 2,3-dihydro-GA31 were produced within 5 hours following 3H-GA9 application to pea shoots. The polar GA-like substances were produced between 5 and 10 hours after 3H-GA9 application. Levels of GA10 increased with time, and since no GA10 was produced during the purification procedures, GA10 was, in all probability, produced from 3H-GA9 within the plant tissue. The radioactive interconversion products produced by pea from 3H-GA9 have chromatographic properties similar to biologically active GA-like substances present in etiolated shoots of dwarf pea. Large scale applications of 3H-GA9 with very low specific activity to etiolated pea shoots showed that the radioactivity of the interconversion products was correlated exactly with biological activity as assayed by dwarf rice (Oryza sativa cv. Tan-ginbozu). PMID:16658838

  19. Transformation of a dwarf Arabidopsis mutant illustrates gibberellin hormone physiology and the function of a Green Revolution gene.

    Science.gov (United States)

    Molina, Isabel; Weber, Katrin; Dos Santos, Déborah Y Alves Cursino; Ohlrogge, John

    2009-05-01

    The introduction of dwarfing traits into crops was a major factor in increased grain yields during the "Green Revolution." In most cases those traits were the consequence of altered synthesis or response to the gibberellin (GA) plant hormones. Our current understanding of GA synthesis and physiology has been facilitated by the characterization of mutants. To introduce concepts about GA hormone physiology and plant transformation in an undergraduate laboratory course we have used ga5, a semi-dwarf Arabidopsis mutant with reduced activity of GA 20-oxidase. In this laboratory exercise, Arabidopsis ga5 mutant plants are transformed by the floral-dip method using Agrobacterium tumefaciens carrying plasmid constructs conferring kanamycin resistance and containing the GA5 gene. Within 4 weeks, seeds of transformed plants can be easily screened by antibiotic resistance on plates. After transfer to soil the dwarf mutant plants transformed with a wild-type version of the gene show normal size. In addition to offering a visual understanding of the effect of GA on stem elongation, students learn additional techniques in this experiment, including PCR and agarose gel electrophoresis. This experiment is cost effective and can be completed within a 4-month term. Copyright © 2009 International Union of Biochemistry and Molecular Biology, Inc.

  20. DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

    Czech Academy of Sciences Publication Activity Database

    Graeber, K.; Linkies, A.; Steinbrecher, T.; Tarkowská, Danuše; Turečková, Veronika; Ignatz, M.; Voegele, A.; Urbanová, Terezie; Strnad, Miroslav; Leubner-Metzger, Gerhard

    2014-01-01

    Roč. 111, č. 34 (2014), E3571-E3580 ISSN 0027-8424 R&D Projects: GA ČR GD522/08/H003; GA MŠk LK21306; GA MŠk(CZ) LO1204; GA ČR GA14-34792S Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional support: RVO:61389030 Keywords : dormancy gene DOG1 * gibberellin metabolism * germination temperature Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.674, year: 2014

  1. Gibberellins interfere with symbiosis signaling and gene expression and alter colonization by arbuscular mycorrhizal fungi in Lotus japonicus.

    Science.gov (United States)

    Takeda, Naoya; Handa, Yoshihiro; Tsuzuki, Syusaku; Kojima, Mikiko; Sakakibara, Hitoshi; Kawaguchi, Masayoshi

    2015-02-01

    Arbuscular mycorrhiza is a mutualistic plant-fungus interaction that confers great advantages for plant growth. Arbuscular mycorrhizal (AM) fungi enter the host root and form symbiotic structures that facilitate nutrient supplies between the symbionts. The gibberellins (GAs) are phytohormones known to inhibit AM fungal infection. However, our transcriptome analysis and phytohormone quantification revealed GA accumulation in the roots of Lotus japonicus infected with AM fungi, suggesting that de novo GA synthesis plays a role in arbuscular mycorrhiza development. We found pleiotropic effects of GAs on the AM fungal infection. In particular, the morphology of AM fungal colonization was drastically altered by the status of GA signaling in the host root. Exogenous GA treatment inhibited AM hyphal entry into the host root and suppressed the expression of Reduced Arbuscular Mycorrhization1 (RAM1) and RAM2 homologs that function in hyphal entry and arbuscule formation. On the other hand, inhibition of GA biosynthesis or suppression of GA signaling also affected arbuscular mycorrhiza development in the host root. Low-GA conditions suppressed arbuscular mycorrhiza-induced subtilisin-like serine protease1 (SbtM1) expression that is required for AM fungal colonization and reduced hyphal branching in the host root. The reduced hyphal branching and SbtM1 expression caused by the inhibition of GA biosynthesis were recovered by GA treatment, supporting the theory that insufficient GA signaling causes the inhibitory effects on arbuscular mycorrhiza development. Most studies have focused on the negative role of GA signaling, whereas our study demonstrates that GA signaling also positively interacts with symbiotic responses and promotes AM colonization of the host root. © 2015 American Society of Plant Biologists. All Rights Reserved.

  2. Roles of Gibberellins and Abscisic Acid in Regulating Germination of Suaeda salsa Dimorphic Seeds Under Salt Stress.

    Science.gov (United States)

    Li, Weiqiang; Yamaguchi, Shinjiro; Khan, M Ajmal; An, Ping; Liu, Xiaojing; Tran, Lam-Son P

    2015-01-01

    Seed heteromorphism observed in many halophytes is an adaptive phenomenon toward high salinity. However, the relationship between heteromorphic seed germination and germination-related hormones under salt stress remains elusive. To gain an insight into this relationship, the roles of gibberellins (GAs) and abscisic acid (ABA) in regulating germination of Suaeda salsa dimorphic brown and black seeds under salinity were elucidated by studying the kinetics of the two hormones during germination of the two seed types with or without salinity treatment. Morphological analysis suggested that brown and black are in different development stage. The content of ABA was higher in dry brown than in black seeds, which gradually decreased after imbibition in water and salt solutions. Salt stress induced ABA accumulation in both germinating seed types, with higher induction effect on black than brown seeds. Black seeds showed lower germination percentage than brown seeds under both water and salt stress, which might be attributed to their higher ABA sensitivity rather than the difference in ABA content between black and brown seeds. Bioactive GA4 and its biosynthetic precursors showed higher levels in brown than in black seeds, whereas deactivated GAs showed higher content in black than brown seeds in dry or in germinating water or salt solutions. High salinity inhibited seed germination through decreasing the levels of GA4 in both seeds, and the inhibited effect of salt stress on GA4 level of black seeds was more profound than that of brown seeds. Taken together higher GA4 content, and lower ABA sensitivity contributed to the higher germination percentage of brown seeds than black seeds in water and salinity; increased ABA content and sensitivity, and decreased GA4 content by salinity were more profound in black than brown seeds, which contributed to lower germination of black seeds than brown seeds in salinity. The differential regulation of ABA and GA homeostases by salt

  3. Overexpression of Jatropha Gibberellin 2-oxidase 6 (JcGA2ox6) Induces Dwarfism and Smaller Leaves, Flowers and Fruits in Arabidopsis and Jatropha

    Science.gov (United States)

    Hu, Ying-Xiong; Tao, Yan-Bin; Xu, Zeng-Fu

    2017-01-01

    Gibberellins (GAs) are plant hormones that play fundamental roles in plant growth and development. Gibberellin 2-oxidase (GA2ox) plays a direct role in determining the levels of bioactive GAs by catalyzing bioactive GAs or their immediate precursors to inactive forms. In this study, a GA2ox gene, designated JcGA2ox6, was isolated from Jatropha curcas. JcGA2ox6 is expressed in all tissues of adult Jatropha, with the highest expression level in male flowers and the lowest expression level in young leaves. Overexpression of JcGA2ox6 in Arabidopsis resulted in a typical dwarf phenotype, along with late flowering, smaller leaves and flowers, shorter siliques and smaller seeds. Similarly, when JcGA2ox6 was overexpressed in Jatropha, the transgenic plants exhibited a dwarf phenotype with dark-green leaves and smaller inflorescences, flowers, fruits and seeds. However, the flowering time of Jatropha was not affected by overexpression of JcGA2ox6, unlike that in the transgenic Arabidopsis. Moreover, the number of flowers per inflorescence, the weight of 10 seeds and the seed oil content were significantly decreased in transgenic Jatropha. The results indicated that overexpression of JcGA2ox6 had a great impact on the vegetative and reproductive growth of transgenic Jatropha. Furthermore, we found that the dwarf phenotype of transgenic Jatropha was caused by a decrease in endogenous bioactive GA4, which was correlated with the degree of dwarfism. PMID:29312375

  4. Herbivory-induced jasmonates constrain plant sugar accumulation and growth by antagonizing gibberellin signaling and not by promoting secondary metabolite production.

    Science.gov (United States)

    Machado, Ricardo A R; Baldwin, Ian T; Erb, Matthias

    2017-07-01

    Plants respond to herbivory by reconfiguring hormonal networks, increasing secondary metabolite production and decreasing growth. Furthermore, some plants display a decrease in leaf energy reserves in the form of soluble sugars and starch, leading to the hypothesis that herbivory-induced secondary metabolite production and growth reduction may be linked through a carbohydrate-based resource trade-off. In order to test the above hypothesis, we measured leaf carbohydrates and plant growth in seven genetically engineered Nicotiana attenuata genotypes that are deficient in one or several major herbivore-induced, jasmonate-dependent defensive secondary metabolites and proteins. Furthermore, we manipulated gibberellin and jasmonate signaling, and quantified the impact of these phytohormones on secondary metabolite production, sugar accumulation and growth. Simulated herbivore attack by Manduca sexta specifically reduced leaf sugar concentrations and growth in a jasmonate-dependent manner. These effects were similar or even stronger in defenseless genotypes with intact jasmonate signaling. Gibberellin complementation rescued carbohydrate accumulation and growth in induced plants without impairing the induction of defensive secondary metabolites. These results are consistent with a hormonal antagonism model rather than a resource-cost model to explain the negative relationship between herbivory-induced defenses, leaf energy reserves and growth. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  5. Overexpression of Jatropha Gibberellin 2-oxidase 6 (JcGA2ox6 Induces Dwarfism and Smaller Leaves, Flowers and Fruits in Arabidopsis and Jatropha

    Directory of Open Access Journals (Sweden)

    Ying-Xiong Hu

    2017-12-01

    Full Text Available Gibberellins (GAs are plant hormones that play fundamental roles in plant growth and development. Gibberellin 2-oxidase (GA2ox plays a direct role in determining the levels of bioactive GAs by catalyzing bioactive GAs or their immediate precursors to inactive forms. In this study, a GA2ox gene, designated JcGA2ox6, was isolated from Jatropha curcas. JcGA2ox6 is expressed in all tissues of adult Jatropha, with the highest expression level in male flowers and the lowest expression level in young leaves. Overexpression of JcGA2ox6 in Arabidopsis resulted in a typical dwarf phenotype, along with late flowering, smaller leaves and flowers, shorter siliques and smaller seeds. Similarly, when JcGA2ox6 was overexpressed in Jatropha, the transgenic plants exhibited a dwarf phenotype with dark-green leaves and smaller inflorescences, flowers, fruits and seeds. However, the flowering time of Jatropha was not affected by overexpression of JcGA2ox6, unlike that in the transgenic Arabidopsis. Moreover, the number of flowers per inflorescence, the weight of 10 seeds and the seed oil content were significantly decreased in transgenic Jatropha. The results indicated that overexpression of JcGA2ox6 had a great impact on the vegetative and reproductive growth of transgenic Jatropha. Furthermore, we found that the dwarf phenotype of transgenic Jatropha was caused by a decrease in endogenous bioactive GA4, which was correlated with the degree of dwarfism.

  6. Translocation of labelled assimilates, ion uptake and nucleic acids contents in zea mays plants as influenced by application of the herbicide dual and the bioregulaators GA3 and kinetin

    International Nuclear Information System (INIS)

    Hassanein, R.AA.; Khodary, S.E.A.; Abdel-Aziz, S.M.

    2001-01-01

    Maize seedlings, grown hydroponic for one month, were undertaken o investigate the effect of dual (metolachlor), bio regulators (GA 3 and kinetin) and their interaction with dual on translocation rate of assimilates, nucleic acids content. ion uptake and the activities of protease and nitrate reductase enzymes. Dual at all concentrations decreased the rate of assimilates translocation and nucleic acids levels. Also reduction in the ability of the treated plants to absorb ions from the growth medium as well as the activities of nitrate reductase and protease enzymes were retarded upon dual application. The results also revealed that treatment with either GA 3 or kinetin in combination with dual, reversed the adverse action of the herbicide on zea mays plants

  7. Effects of gibberellin A4/7, 6-benzylaminopurine and chlormequat chloride on the number of male and female strobili and immature cones in Chinese pine (Pinus tabuliformis) with foliar sprays

    Science.gov (United States)

    Peng Zhao; Jun-feng Fan; Shuo-xin Zhang; Zhong-lian Huang; Pei-hua Yang; Zhen-Hua Ma; Keith W Woeste

    2011-01-01

    Three kinds of plant growth regulators, gibberellinA4/7 (GA4/7), 6-benzylaminopurine (BA), and chlormequat chloride (CCC), were evaluated for their ability to promote strobilus and cone production in a Chinese pine (Pinus tabuliformis Carr.) clonal seed orchard. Treatments (0, 250, 500, or 1000 mg⋅L

  8. Gibberellin Deficiency Confers Both Lodging and Drought Tolerance in Small Cereals

    Directory of Open Access Journals (Sweden)

    Sonia ePlaza-Wüthrich

    2016-05-01

    Full Text Available Tef [Eragrostis tef (Zucc. Trotter] and finger millet [Eleusine coracana Gaertn] are staple cereal crops in Africa and Asia with several desirable agronomic and nutritional properties. Tef is becoming a life-style crop as it is gluten-free while finger millet has a low glycemic index which makes it an ideal food for diabetic patients. However, both tef and finger millet have extremely low grain yields mainly due to moisture scarcity and susceptibility of the plants to lodging. In this study, the effects of gibberellic acid (GA inhibitors particularly paclobutrazol (PBZ on diverse physiological and yield-related parameters were investigated and compared to GA mutants in rice (Oryza sativa L.. The application of PBZ to tef and finger millet significantly reduced the plant height and increased lodging tolerance. Remarkably, PBZ also enhanced the tolerance of both tef and finger millet to moisture deficit. Under moisture scarcity, tef plants treated with PBZ did not exhibit drought-related symptoms and their stomatal conductance was unaltered, leading to higher shoot biomass and grain yield. Semi-dwarf rice mutants altered in GA biosynthesis, were also shown to have improved tolerance to dehydration. The combination of traits (drought tolerance, lodging tolerance and increased yield that we found in plants with altered GA pathway is of importance to breeders who would otherwise rely on extensive crossing to introgress each trait individually. The key role played by PBZ in the tolerance to both lodging and drought calls for further studies using mutants in the GA biosynthesis pathway in order to obtain candidate lines which can be incorporated into crop-breeding programs to create lodging tolerant and climate-smart crops.

  9. Efeito de ácido giberélico, GA3, e GA4 + GA7 em pós-colheita de crisântemo e solidago.

    Directory of Open Access Journals (Sweden)

    Denise Laschii

    1999-05-01

    Full Text Available O experimento foi instalado no laboratório do Departamento de Horticultura da FCA/ UNESP, no período de 14 de novembro a 3 de dezembro de 1998. As hastes de crisântemo (Dendranthema grandiflora Tzvelev e solidago (Solidago canadensis L. foram selecionadas e colocadas em solução de "pulsing", por 24 horas, visando avaliar as respostas aos seguintes tratamentos: Água (testemunha, GA3 10 mg.L-1 (Pro-Gibb; GA3 20 mg.L-I; GA3 30 mg.L-I; GA4 + GA7 10 mg.L-1 (Pro-Vibe, GA4 + GA7 20 mg.L-1 e GA4 + GA7 30 mg.L-1. Após os tratamentos de "pulsing", as hastes foram colocadas em recipientes contendo 1.000 mL de água, que foi trocada a cada dois dias. Avaliou-se o número de dias até o descarte, tanto para hastes de solidago quanto para crisântemo, para cada tratamento testado. Avaliou--se também a qualidade das folhas de solidago conforme o seguinte critério: índice de qualidade (IQ = 3 (folhas verdes, IQ = 2 (folhas em início de amarelecimento e IQ = 1 (folhas amarelas ou queimadas. Pelos resultados concluiu-se que: hastes cortadas de solidago e crisântemo diferiram quanto às respostas aos tratamentos pós-colheita, em relação ao tipo de giberelina utilizada; GA4 + GA7 10 mg.L-1 foi eficiente na manutenção da qualidade de hastes cortadas de solidago, e GA3 nas concentrações utilizadas no experimento apresentaram efeito deletério nas folhas de solidago; GA3 10 e 20 mg.L-1 foram mais eficientes na manutenção da qualidade pós-colheita de hastes de crisântemo.

  10. Effect of gibberellin, auxin and kinetin treatments combined with foliar applied NPK on the yield of Capsicum annuum L. fruits and their capsaicin content

    Directory of Open Access Journals (Sweden)

    Tomasz J. Nowak

    2013-12-01

    Full Text Available The Wrocław version of hydroponic culture was applied. Under optimal conditions of root fertilization the plants were sprayed with growth regulators sueh as gibberellins, auxins and kinetins, and .their mixtures. Each growth regulator treatment was applied with or without NPK added. The influence of these treatments on the fresh and dry weight of the fruit, percentage of ripe fruits and content and yield of capsaicin was studied. The highest yield of fruits and capsaicin. was obtained from plants sprayed with gibberellic acid and kinetin (in concentrations of 10 and 5 mg/l, respectively together with NPK foliar application. No influence of ,growth regulators and foliar-applied NPK was noted on capsaicin content and dry weight of fruits.

  11. Effects of gibberellin A(4/7), root pruning and cytokinins on seed and pollen cone production in black spruce (Picea mariana).

    Science.gov (United States)

    Smith, Ron; Greenwood, Michael

    1995-01-01

    Stem injections of 8-9-year-old black spruce (Picea mariana (Mill.) B.S.P.) trees with gibberellin A(4/7) (GA(4/7)) alone and in combination with root pruning increased both seed and pollen cone production in both 1991 and 1992. Combining GA(4/7) and root pruning produced a larger increase in reproductive bud production than either treatment alone, but the complementary effects were less during the warm dry summer in 1991 than during the wet summer in 1992. Cytokinin applications reduced the stimulatory effects of GA(4/7) and root pruning, and the degree of reduction varied with the amount and timing of application. Reduced reproductive bud production was attributed to cytokinin countering the effects of root pruning and natural drought on the GA(4/7) response.

  12. The effects of benzil amino purin (BAP and gibberellin with in vitro seedling growth of pulesari (Alyxia reinwardtii Bl

    Directory of Open Access Journals (Sweden)

    Heru Sudrajad

    2016-12-01

    vulnerable status. The high price and high market demand made the over harvested beyond regeneration capacity of the plant while the conservation efforts are terribly limited. Presentage of seed germination is not only very low but also time consuming, therefore we conducting preliminary study on in vitro propagation using  seed  Alyxia reinwardtii Bl. Methods: The research was conducted in laboratory tissue culture of Medicinal Plant and Traditional Medicine Research and Development Center Tawangmangu for three months. Seeds of A. reinwardtii Bl. obtained from Pringgondani Forest, Tawangmangu Central Java.  Seeds were peeled and air dryed for five days, washed using steril aquadest, soaked on 0.5% Agrept (5 minutes then on 2.125% sodium hypochloride (5 minutes and rinsed using sterile distilled water. This study uses a Murashige and Skoog (MS with a completely randomized design (CRD factorial design.. The first factor is   BAP at a concentration of 3, 4, 5 mg.L-1 and the second factor is giberelin concentration of 1, 2, 3 mg.L-1. MS media  with addition of BAP the concentration of 3, 4, 5 mg.L-1 and gibberellin the concentration of 1, 2, 3 mg.L-1 obtained 9 treatment combination. Results: The results showed the combination treatment of growth regulators BAP (4 mg.L-1 and giberelin (2 mg.L-1 is formed shoots and roots. The shoots were formed  30 days after planting with a height of 2 cm and the roots appear at 45 days after planting. Conclusion: Pulasari (Alyxia reinwardtii Bl. can be propagated through tissue culture using seeds as explants.Keywords: pulesari, Alyxia reinwardtii BI, BAP and giberelin 

  13. Transcriptomic analysis reveals the roles of gibberellin-regulated genes and transcription factors in regulating bolting in lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Liu, Xueying; Lv, Shanshan; Liu, Ran; Fan, Shuangxi; Liu, Chaojie; Liu, Renyi; Han, Yingyan

    2018-01-01

    A cool temperature is preferred for lettuce cultivation, as high temperatures cause premature bolting. Accordingly, exploring the mechanism of bolting and preventing premature bolting is important for agriculture. To explore this relationship in depth, morphological, physiological, and transcriptomic analyses of the bolting-sensitive line S39 at the five-leaf stage grown at 37°C were performed in the present study. Based on paraffin section results, we observed that S39 began bolting on the seventh day at 37°C. During bolting in the heat-treated plants, GA3 and GA4 levels in leaves and the indoleacetic acid (IAA) level in the stem reached a maximum on the sixth day, and these high contents were maintained. Additionally, bolting begins in the fifth day after GA3 treatment in S39 plants, GA3 and GA4 increased and then decreased, reaching a maximum on the fourth day in leaves. Similarly, IAA contents reached a maximum in the stem on the fifth day. No bolting was observed in the control group grown at 25°C, and significant changes were not observed in GA3 and GA4 levels in the controls during the observation period. RNA-sequencing data implicated transcription factors (TFs) in regulating bolting in lettuce, suggesting that the high GA contents in the leaves and IAA in the stem promote bolting. TFs possibly modulate the expression of related genes, such as those encoding hormones, potentially regulating bolting in lettuce. Compared to the control group, 258 TFs were identified in the stem of the treatment group, among which 98 and 156 were differentially up- and down-regulated, respectively; in leaves, 202 and 115 TFs were differentially up- and down-regulated, respectively. Significant changes in the treated group were observed for C2H2 zinc finger, AP2-EREBP, and WRKY families, indicating that these TFs may play important roles in regulating bolting.

  14. Effect of GA3, KNO3, and removing of basal point of seeds on germination of sweet granadilla (Passiflora ligularis Juss and yellow passion fruit (Passiflora edulis f. flavicarpa

    Directory of Open Access Journals (Sweden)

    Julián Cárdenas

    2013-09-01

    Full Text Available Passiflora seeds germinate erratically presenting difficulties for their handling in a greenhouse. The effect of removing of basal point of seeds (RB and pre-imbibition of seeds of sweet granadilla and yellow passion fruit in 50, 100, 200, and 400 mg mL-1 solutions of gibberellic acid (GA3 or 0.1% KNO3 solution was studied. The experiment was conducted in greenhouses in La Plata, Colombia. Two accessions PrJ1 and PrJ2 of sweet granadilla were evaluated. There were calculated the final percentage of germination (PG, mean germination time (MGT, and the mean germination rate (MGR. The leaf area and dry mass of seedlings were measured 22 days after sowing (das; with this data, specific leaf area and relation root/shoot were calculated. In all cases, the highest germination percentages were achieved treating seeds with KNO3 (89, 92, and 87% for yellow passion fruit, PrJ2, and PrJ1, respectively, but the increase in MGR (3.3 germinated seeds per day and the decrease in MGT (16 days were only significant for PrJ1. RB had a significant reduction of PG in all cases (28, 12, and 33% for passion fruit, PrJ2 and PrJ1, respectively. With the increase in the concentration of GA3, PG was reduced for two accessions of sweet granadilla, for yellow passion fruit this trend was not clear, no treatment with GA3 showed significant differences with the control. Leaf area (24.07 cm2 and dry mass of seedlings (135 mg were significantly higher than seeds previously treated with KNO3 only for PrJ1.The solution of KNO3 0,1% is recommended to improve the germination and initial growth of granadilla seedlings.

  15. An N-terminal region of a Myb-like protein is involved in its intracellular localization and activation of a gibberellin-inducible proteinase gene in germinated rice seeds.

    Science.gov (United States)

    Sutoh, Keita; Washio, Kenji; Imai, Ryozo; Wada, Masamitsu; Nakai, Tomonori; Yamauchi, Daisuke

    2015-01-01

    The expression of the gene for a proteinase (Rep1) is upregulated by gibberellins. The CAACTC regulatory element (CARE) of the Rep1 promoter is involved in the gibberellin response. We isolated a cDNA for a CARE-binding protein containing a Myb domain in its carboxyl-terminal region and designated the gene Carboxyl-terminal Myb1 (CTMyb1). This gene encodes two polypeptides of two distinctive lengths, CTMyb1L and CTMyb1S, which include or exclude 213 N-terminal amino acid residues, respectively. CTMyb1S transactivated the Rep1 promoter in the presence of OsGAMyb, but not CTMyb1L. We observed an interaction between CTMyb1S and the rice prolamin box-binding factor (RPBF). A bimolecular fluorescence complex analysis detected the CTMyb1S and RPBF complex in the nucleus, but not the CTMyb1L and RPBF complex. The results suggest that the arrangement of the transfactors is involved in gibberellin-inducible expression of Rep1.

  16. Effect of size and site preference of trivalent non-magnetic metal ions (Al3+, Ga3+, In3+) substituted for Fe3+ on the magnetostrictive properties of sintered CoFe2O4

    Science.gov (United States)

    Anantharamaiah, P. N.; Joy, P. A.

    2017-11-01

    The influence of size and crystallographic site preference of three non-magnetic isovalent metal ions of larger (In3+), comparable (Ga3+) and smaller (Al3+) sizes, substituted for Fe3+ in the spinel lattice of CoFe2O4 on its magnetostrictive properties is compared. For the different compositions in CoFe2-x M x O4 (M  =  In3+, Ga3+, Al3+ and 0  ⩽  x  ⩽  0.3), significant changes in the structural and magnetic parameters are observed with the degree of substitution, due to the size and site preferences. Magnetic and Raman spectral studies revealed that Al3+ is substituted for Fe3+ at both octahedral and tetrahedral sites for all compositions, whereas In3+ and Ga3+ are substituted for Fe3+ at the tetrahedral site only for x  ⩽  0.2 and partly at the octahedral site for x  >  0.2. Regardless of the differences in the ionic size, site preference and the magnetic properties, compositions in all three series with x  =  0.1 showed almost equal magnitude of maximum magnetostriction (λ max  =  ~230 ppm), marginally higher than that of x  =  0 (217 ppm). However, at higher substituted compositions, λ max is decreased with x, but the decrease is much faster for the Al-substituted compositions. The maximum strain sensitivity, [dλ/dH]max, is also found to be comparable for all three compositions. The comparable magnetostriction characteristics and high strain at low magnetic fields for different substituted compositions at low levels of substitution are attributed to the local structural distortions associated with the inhomogeneous distribution of the substituted ions in the spinel ferrite lattice. The studies suggest ways to optimise the magnetostriction properties of properly substituted sintered cobalt ferrite for applications in sensors and actuators.

  17. Influência da concentração de BAP e AG3 no desenvolvimento in vitro de mandioquinha-salsa Influence of BAP and GA3 concentration on the in vitro development of arracacha

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    Nuno R. Madeira

    2005-12-01

    Full Text Available Foram realizados dois experimentos com o objetivo de avaliar o efeito das concentrações de BAP e de AG3 no desenvolvimento in vitro de mandioquinha-salsa. Foram avaliadas as concentrações de 0,0; 0,2 e 0,4 mg L-1 de BAP e de 0,0; 0,125 e 0,250 mg L-1 de AG3 no desenvolvimento de ápices caulinares com cerca de 2 mm das cultivares Amarela de Senador Amaral e Amarela Comum. A interação cultivares x concentração de BAP não foi significativa para nenhuma das características avaliadas (P>0,0617. O aumento na concentração de BAP reduziu a formação de calos; entretanto, promoveu proporcionalmente redução no desenvolvimento da parte aérea. A concentração de BAP que apresentou os melhores resultados foi em torno de 0,3 mg L-1 de BAP, conciliando diâmetro de calo relativamente reduzido e bom desenvolvimento da parte aérea, cerca de 4,5 brotos com altura média de 43 mm. A interação cultivares x concentração de AG3 não foi significativa para nenhuma das características avaliadas (P>0,4310. O aumento na concentração de AG3 promoveu elevação significativa na altura média e máxima das brotações e aumento no tamanho de calos. Nos dois experimentos, observou-se maior número de brotações na cultivar Amarela Comum.Two experiments were carried out to evaluate the effect of BAP and GA3 concentrations on the in vitro arracacha development. The concentrations tested were 0.0; 0.2 and 0.4 mg L-1 of BAP and 0.0; 0.125 and 0.250 mg L-1 of GA3 in the shoot tips with about 2 mm of arracacha, cultivars Amarela de Senador Amaral and Amarela Comum. The interaction of cultivars x BAP concentration was not significant for any one of the evaluated variables (P>0,0617. The increase in the BAP concentration reduced the callus formation; however, promoted larger reduction in the shoot development. The best BAP concentration was around 0.3 mg L-1, with relatively reduced callus diameter and good development of shoot, with a mean of 4.5 shoots

  18. Spectral and laser properties of Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 crystal at 1.55 µm

    Science.gov (United States)

    Gong, Guoliang; Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

    2018-04-01

    An Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 (CNGS) crystal was grown by the Czochralski method. Spectral properties of the crystal, including the polarized absorption and fluorescence spectra, the fluorescence decay, as well as the energy transfer efficiency from Yb3+ to Er3+ were investigated in detail. End-pumped by a 976 nm diode laser, a 1556 nm continuous-wave laser with a maximum output power of 202 mW and a slope efficiency of 11.4% was achieved in the Er,Yb,Ce:CNGS crystal. The results indicate the Er,Yb,Ce:CNGS crystal is a promising 1.55 µm laser gain medium.

  19. Lale Yetiştiriciliğinde Büyüme, Gelişme, Kalite ve Erkencilik Üzerine Gibberellik Asit (GA3 Uygulamalarının Etkileri

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    Gamze ZENGİN

    2016-06-01

    Full Text Available Araştırma, Cafe noir ve Conqueror lale çeşitlerinin sürme zamanı, sürme oranı, yaprak sayısı, çiçek açma zamanı, çiçek çapı, çiçek boyu, çiçeklenme süresi, çiçeklenme oranı, bitki boyu, çiçek sap uzunluğu, soğan sayısı, soğan ağırlığı üzerine farklı Gibberellik Asit (GA3 dozlarının (100, 300, 500 ve 700 ppm ve uygulama sürelerinin (30 ve 60 dakika etkilerinin belirlenmesi amacıyla cam serada yürütülmüştür. Araştırmada yetiştirme ortamı olarak %50 kompost, %30 perlit, %20 bahçe toprağı kullanılmıştır. Araştırmada, lalenin büyüme, gelişme, erkencilik ve kalite özellikleri üzerine uygulamaların ve çeşitlerin etkileri önemli bulunmuştur. Lale yetiştiriciliğinde GA3 hormon dozlarının çiçeklenme zamanı, çiçeklenme oranı, çiçek sap uzunluğu,  bitki boyu, soğan sayısı ve soğan ağırlığı bakımından; hormon uygulama sürelerinin ise bitki boyu ve soğan ağırlığı bakımından önemli olduğu saptanmıştır. Tüm uygulamalardan %99’un üzerinde bir sürme oranı elde edilmiştir. Conqueror çeşidinin Cafe noir çeşidine göre 9 ile 15 gün kadar erken sürdüğü belirlenmiştir. Uygulamalara göre ilk çiçeklenme dikimden itibaren 47 ile 65 gün içinde gerçekleşmiştir. Conqueror çeşidinde ilk çiçeklenme 13 Ocakta 60 dakika 300 ppm GA3 uygulamasından;  Cafe noir çeşidine ilk çiçeklenme 31 Ocak’ta 60 dakika 700 ppm GA3 uygulamasından elde edilmiştir.

  20. Aplicação de AG3 e CPPU na qualidade da uva 'Itália' em Porto Feliz-SP GA3 and CPPU application on 'Itália' grapes grown in Porto Feliz-SP

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    Alessandro Rodrigues

    2011-03-01

    Full Text Available A videira 'Itália' (Vitis vinifera L. é a cultivar de uva fina para mesa mais consumida no Brasil. A qualidade dos cachos é uma característica fundamental, sendo o tamanho das bagas o componente mais valorizado pelos consumidores. Uma das alternativas para incrementar a qualidade das bagas é o uso de biorreguladores. Avaliaram-se, em três ciclos de produção, os efeitos de doses de ácido giberélico (AG3 isolado e associado com forchlorfenuron (CPPU, na qualidade dos cachos de uva Itália produzida em Porto Feliz-SP. A aplicação dos biorreguladores foi realizada aos 25 dias após o florescimento, em delineamento experimental inteiramente casualizado, em fatorial 4X4 (zero, 10; 20 e 30 mg L-1 AG3 X zero, 5; 10 e 15 mg L-1 CPPU, com oito repetições para o primeiro ciclo, e fatorial 3X3 (zero, 20 e 30 mg L-1 AG3 X zero, 10 e 20 mg L-1 CPPU com dez repetições para o segundo e terceiro ciclos. A mistura de 20 mg L-1 de AG3 com 10 mg L-1 de CPPU promoveu o incremento do comprimento e do diâmetro das bagas sem prejuízo da massa dos cachos, melhorando sua qualidade, em Porto Feliz-SP. O uso de CPPU isoladamente acarretou em redução do teor de sólidos solúveis das bagas.'Itália' grape (Vitis vinifera L. is one of the main varieties for fresh market in Brazil. Cluster quality is determinant for commercialization and the berry size is highly valued by consumers. An alternative for improving berry size is the use of growth regulators. The effect of increasing concentrations of gibberellic acid (GA3 and forchlorfenuron (CPPU applied alone or in mixtures was evaluated during three production cycles. Growth regulators were applied 25 days after flowering in the "pea berry size" phenologic stage. Experimental design was completely randomized 4x4 factorial (zero, 10, 20 and 30 mg L-1 GA3 X zero, 5, 10 and 15 mg L-1 CPPU with eight replications for the first cycle, and 3X3 factorial (zero, 20 and 30 mg L-1 GA3 X zero, 10 and 20 mg L-1 CPPU

  1. Ácido giberélico (ga3 e 6-benzilaminopurina (bap no crescimento in vitro de macela [Egletes viscosa (L. Less.] Giberelic acid and 6-benzilaminopurine on in vitro growth of macela [Egletes viscosa (L. Less.

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    Josefa Diva Nogueira Diniz

    2003-08-01

    Full Text Available A micropropagação é uma ferramenta promissora que pode ser utilizada para propagação e preservação de muitas espécies de plantas medicinais que vêm sendo exploradas de forma indiscriminada e que estão em vias de extinção. Conduziu-se este trabalho com o objetivo de induzir o crescimento in vitro de brotações de macela, em meio de cultura MS com diferentes concentrações de GA3 (0; 0,1 e 0,5 mgL-1 e BAP (0; 1 e 2 mgL-1. Foram utilizadas brotações de macela com diâmetro médio de 1,5 cm, retiradas de plantas preestabelecidas in vitro, inoculadas em frascos contendo 40 ml do meio de cultura e mantidas em sala de crescimento com temperatura média de 26 ± 1oC, fotoperíodo de 16 h e intensidade luminosa em torno de 2000 lux fornecida por lâmpada tipo fluorescente branca fria. Utilizou-se como delineamento experimental um fatorial 3 x 3, num total de nove tratamentos com 15 explantes por tratamento. Aos 30 dias, verificou-se o maior crescimento em altura das plantas, no tratamento com 0,5 mgL-1 de GA3 na ausência de BAP. O maior número de brotações ou crescimento em diâmetro foi observado com maiores concentrações dos reguladores. Porém, na presença dos reguladores ocorreu um maior número de plantas com folhas hiperhídricas e malformadas.Micropropagation is a promising tool that can be utilized for propagation and preservation of many medicinal species that are being explored in an indiscriminated form and are under the risk of extinction. This work had as an objective to induce the growth in vitro of macela clusters in MS culture medium with different concentrations of GA3 (0, 0.1 and 0.5 mgL-1 and BAP (0, 1.0 and 2.0 mgL-1. Macela clusters or buddings with 1.5 cm of average diameter obtained from in vitro established plants were inoculated in glass containing 40ml of culture medium and keept in a growing room with light (2000 lux supplied by cool white fluorescent lamps for 16 hours daily at 26 ± 1oC. The experiment

  2. Biosynthetic origin of gibberellins A sub 3 and A sub 7 in cell-free preparations from seeds of Marah macrocarpus and Malus domestica

    Energy Technology Data Exchange (ETDEWEB)

    Albone, K.S.; Gaskin, P.; MacMillan, J.; Willis, C.L. (Univ. of Bristol (England)); Phinney, B.O. (Univ. of California, Los Angeles (USA))

    1990-09-01

    Cell-free preparations from seeds of Marah macrocarpus L. and Malus domestica L. catalyzed the conversion of gibberellin A{sub 9} (GA{sub 9}) and 2,3-dehydroGA{sub 9} to GA{sub 7}; GA{sub 9} was also metabolized to GA{sub 4} in a branch pathway. The preparation from Marah seeds also metabolized GA{sub 5} to GA{sub 3} in high yield; GA{sub 6} was a minor product and was not metabolized to GA{sub 3}. Using substrates stereospecifically labeled with deuterium, it was shown that the metabolism of GA{sub 5} to GA{sub 3} and of 2,3-dehydroGA{sub 9} to GA{sub 7} occurs with the loss of the 1{beta}-hydrogen. In cultures of Gibberella fujikuroi, mutant B1-41a, (1{beta},2{beta}-{sup 2}H{sub 2})GA{sub 4}, was metabolized to (1,2-{sup 2}H{sub 2})GA{sub 3} with the loss of the 1{alpha}- and 2{alpha}-hydrogens. These results provide further evidence that the biosynthetic origin of GA{sub 3} and GA{sub 7} in higher plants is different from that in the fungus Gibberella fujikuroi.

  3. Molecular cloning and characterization of a cDNA encoding the gibberellin biosynthetic enzyme ent-kaurene synthase B from pumpkin (Cucurbita maxima L.).

    Science.gov (United States)

    Yamaguchi, S; Saito, T; Abe, H; Yamane, H; Murofushi, N; Kamiya, Y

    1996-08-01

    The first committed step in the formation of diterpenoids leading to gibberellin (GA) biosynthesis is the conversion of geranylgeranyl diphosphate (GGDP) to ent-kaurene. ent-Kaurene synthase A (KSA) catalyzes the conversion of GGDP to copalyl diphosphate (CDP), which is subsequently converted to ent-kaurene by ent-kaurene synthase B (KSB). A full-length KSB cDNA was isolated from developing cotyledons in immature seeds of pumpkin (Cucurbita maxima L.). Degenerate oligonucleotide primers were designed from the amino acid sequences obtained from the purified protein to amplify a cDNA fragment, which was used for library screening. The isolated full-length cDNA was expressed in Escherichia coli as a fusion protein, which demonstrated the KSB activity to cyclize [3H]CDP to [3H]ent-kaurene. The KSB transcript was most abundant in growing tissues, but was detected in every organ in pumpkin seedlings. The deduced amino acid sequence shares significant homology with other terpene cyclases, including the conserved DDXXD motif, a putative divalent metal ion-diphosphate complex binding site. A putative transit peptide sequence that may target the translated product into the plastids is present in the N-terminal region.

  4. Endogenous gibberellins in Arabidopsis thaliana and possible steps blocked in the biosynthetic pathways of the semidwarf ga4 and ga5 mutants

    International Nuclear Information System (INIS)

    Talon, M.; Zeevaart, J.A.D.; Koornneef, M.

    1990-01-01

    Twenty gibberellins (GAs) have been identified in extracts from shoots of the Landsberg erecta line of Arabidopsis thaliana by full-scan gas chromatography-mass spectrometry and Kovats retention indices. Eight of them are members of the early-13-hydroxylation pathway (GA 53 , GA 44 , GA 19 , GA 17 , GA 20 , GA 1 , GA 29 , and GA 8 ), six are members of the early-3-hydroxylation pathway (GA 37 , GA 27 , GA 36 , GA 13 , GA 4 , and GA 34 ), and the remaining six are members of the non-3,13-hydroxylation pathway (GA 12 , GA 15 , GA 24 , GA 25 , GA 9 , and GFA 51 ). Seven of these GAs were quantified in the Landsberg erecta line of Arabidopsis and in the semidwarf ga4 and ga5 mutants by gas chromatography-selected ion monitoring (SIM) using internal standards. The relative levels of the remaining 13 GAs were compared by the use of ion intensities only. The growth-response data, as well as the accumulation of GA 9 in the ga4 mutant, indicate that GA 9 is not active in Arabidopsis, but it must be 3β-hydroxytlated to GA 4 to become bioactive. It is concluded that the reduced levels of the 3β-hydroxy-GAs, GA 1 and GA 4 , are the cause of the semidwarf growth habit of both mutants

  5. Gene Co-Expression Analysis Inferring the Crosstalk of Ethylene and Gibberellin in Modulating the Transcriptional Acclimation of Cassava Root Growth in Different Seasons.

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    Treenut Saithong

    Full Text Available Cassava is a crop of hope for the 21st century. Great advantages of cassava over other crops are not only the capacity of carbohydrates, but it is also an easily grown crop with fast development. As a plant which is highly tolerant to a poor environment, cassava has been believed to own an effective acclimation process, an intelligent mechanism behind its survival and sustainability in a wide range of climates. Herein, we aimed to investigate the transcriptional regulation underlying the adaptive development of a cassava root to different seasonal cultivation climates. Gene co-expression analysis suggests that AP2-EREBP transcription factor (ERF1 orthologue (D142 played a pivotal role in regulating the cellular response to exposing to wet and dry seasons. The ERF shows crosstalk with gibberellin, via ent-Kaurene synthase (D106, in the transcriptional regulatory network that was proposed to modulate the downstream regulatory system through a distinct signaling mechanism. While sulfur assimilation is likely to be a signaling regulation for dry crop growth response, calmodulin-binding protein is responsible for regulation in the wet crop. With our initiative study, we hope that our findings will pave the way towards sustainability of cassava production under various kinds of stress considering the future global climate change.

  6. A Zinc Finger Protein Regulates Flowering Time and Abiotic Stress Tolerance in Chrysanthemum by Modulating Gibberellin Biosynthesis[C][W][OPEN

    Science.gov (United States)

    Yang, Yingjie; Ma, Chao; Xu, Yanjie; Wei, Qian; Imtiaz, Muhammad; Lan, Haibo; Gao, Shan; Cheng, Lina; Wang, Meiyan; Fei, Zhangjun; Hong, Bo; Gao, Junping

    2014-01-01

    Flowering time and an ability to tolerate abiotic stresses are important for plant growth and development. We characterized BBX24, a zinc finger transcription factor gene, from Chrysanthemum morifolium and found it to be associated with both flowering time and stress tolerance. Transgenic lines with suppressed expression of Cm-BBX24 (Cm-BBX24-RNAi) flowered earlier than wild-type plants and showed decreased tolerance to freezing and drought stresses. Global expression analysis revealed that genes associated with both photoperiod and gibberellin (GA) biosynthesis pathways were upregulated in Cm-BBX24-RNAi lines, relative to the wild type. By contrast, genes that were upregulated in overexpressing lines (Cm-BBX24-OX), but downregulated in Cm-BBX24-RNAi lines (both relative to the wild type), included genes related to compatible solutes and carbohydrate metabolism, both of which are associated with abiotic stress. Cm-BBX24 expression was also influenced by daylength and GA4/7 application. Under long days, changes in endogenous GA1, GA4, GA19, and GA20 levels occurred in young leaves of transgenic lines, relative to the wild type. Regulation of flowering involves the FLOWERING TIME gene, which integrates photoperiod and GA biosynthesis pathways. We postulate that Cm-BBX24 plays a dual role, modulating both flowering time and abiotic stress tolerance in chrysanthemum, at least in part by influencing GA biosynthesis. PMID:24858937

  7. One-pot preparation of a mixed-mode organic-silica hybrid monolithic capillary column and its application in determination of endogenous gibberellins in plant tissues.

    Science.gov (United States)

    Zhang, Zheng; Hao, Yan-Hong; Ding, Jun; Xu, Sheng-Nan; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-10-16

    A newly improved one-pot method, based on "thiol-ene" click chemistry and sol-gel approach in microemulsion system, was developed for the preparation of C8/PO(OH)2-silica hybrid monolithic capillary column. The prepared monolith possesses large specific surface area, narrow mesopore size distribution and high column efficiency. The monolithic column was demonstrated to have cation exchange/reversed-phase (CX/RP) mixed-mode retention for analytes on nano-liquid chromatography (nano-LC). On the basis of the developed nano-LC system with MS detector coupled to pipette tip solid phase extraction (PT-SPE) and derivatization process, we then realized simultaneous determination of 10 gibberellins (GAs) with low limits of detection (LODs, 0.003-0.025 ng/mL). Furthermore, 6 endogenous GAs in only 5mg rice leaves (fresh weight) were successfully detected and quantified. The developed PT-SPE-nano-LC-MS strategy may offer promising applications in the determination of low abundant bioactive molecules from complex matrix. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Enterobacter sp. I-3, a bio-herbicide inhibits gibberellins biosynthetic pathway and regulates abscisic acid and amino acids synthesis to control plant growth.

    Science.gov (United States)

    Radhakrishnan, Ramalingam; Park, Jae-Man; Lee, In-Jung

    2016-12-01

    Very few bacterial species were identified as bio-herbicides for weed control. The present research was focused to elucidate the plant growth retardant properties of Enterobacter sp. I-3 during their interaction by determining the changes in endogenous photosynthetic pigments, plant hormones and amino acids. The two bacterial isolates I-4-5 and I-3 were used to select the superior bacterium for controlling weed seeds (Echinochloa crus-galli L. and Portulaca oleracea L.) germination. The post-inoculation of I-3 (Enterobacter sp. I-3) significantly inhibited the weeds seed germination than their controls. The mechanism of bacterium induced plant growth reduction was identified in lettuce treated with I-3 bacterium and compared their effects with known chemical herbicide, trinexapac-ethyl (TE). The treatment of I-3 and TE showed a significant inhibitory effect on shoot length, leaf number, leaf length, leaf width, shoot weight, root weight and chlorophyll content in lettuce seedlings. The endogenous gibberellins (GAs) and abscisic acid (ABA) analysis showed that Enterobacter sp. I-3 treated plants had lower levels of GAs (GA 12 , GA 19 , GA 20 and GA 8 ) and GAs/ABA ratio and then, the higher level of ABA when compared to their controls. Indeed, the individual amino acids ie., aspartic acid, glutamic acid, glycine, threonine, alanine, serine, leucine, isoleucine and tyrosine were declined in TE and I-3 exposed plants. Our results suggest that the utilization of Enterobacter sp. I-3 inhibits the GAs pathway and amino acids synthesis in weeds to control their growth can be an alternative to chemical herbicides. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. A GRAS-like gene of sunflower (Helianthus annuus L.) alters the gibberellin content and axillary meristem outgrowth in transgenic Arabidopsis plants.

    Science.gov (United States)

    Fambrini, M; Mariotti, L; Parlanti, S; Salvini, M; Pugliesi, C

    2015-11-01

    The GRAS proteins belong to a plant transcriptional regulator family that function in the regulation of plant growth and development. Despite their important roles, in sunflower only one GRAS gene (HaDella1) with the DELLA domain has been reported. Here, we provide a functional characterisation of a GRAS-like gene from Helianthus annuus (Ha-GRASL) lacking the DELLA motif. The Ha-GRASL gene contains an intronless open reading frame of 1,743 bp encoding 580 amino acids. Conserved motifs in the GRAS domain are detected, including VHIID, PFYRE, SAW and two LHR motifs. Within the VHII motif, the P-H-N-D-Q-L residues are entirely maintained. Phylogenetic analysis reveals that Ha-GRASL belongs to the SCARECROW LIKE4/7 (SCL4/7) subfamily of the GRAS consensus tree. Accumulation of Ha-GRASL mRNA at the adaxial boundaries from P6/P7 leaf primordia suggests a role of Ha-GRASL in the initiation of median and basal axillary meristems (AMs) of sunflower. When Ha-GRASL is over-expressed in Arabidopsis wild-type plants, the number of lateral bolts increases differently from untransformed plants. However, Ha-GRASL slightly affects the lateral suppressor (las-4-) mutation. Therefore, we hypothesise that Ha-GRASL and LAS are not functionally equivalent. The over-expression of Ha-GRASL reduces metabolic flow of gibberellins (GAs) in Arabidopsis and this modification could be relevant in AM development. Phylogenetic analysis includes LAS and SCL4/7 in the same major clade, suggesting a more recent separation of these genes with respect to other GRAS members. We propose that some features of their ancestor, as well as AM initiation and outgrowth, are partially retained in both LAS and SCL4/7. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. ACC synthase genes are polymorphic in watermelon (Citrullus spp.) and differentially expressed in flowers and in response to auxin and gibberellin.

    Science.gov (United States)

    Salman-Minkov, Ayelet; Levi, Amnon; Wolf, Shmuel; Trebitsh, Tova

    2008-05-01

    The flowering pattern of watermelon species (Citrullus spp.) is either monoecious or andromonoecious. Ethylene is known to play a critical role in floral sex determination of cucurbit species. In contrast to its feminizing effect in cucumber and melon, in watermelon ethylene promotes male flower development. In cucumber, the rate-limiting enzyme of ethylene biosynthesis, 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), regulates unisexual flower development. To investigate the role of ethylene in flower development, we isolated four genomic sequences of ACS from watermelon (CitACS1-4). Both CitACS1 and CitACS3 are expressed in floral tissue. CitACS1 is also expressed in vegetative tissue and it may be involved in cell growth processes. Expression of CitACS1 is up-regulated by exogenous treatment with auxin, gibberellin or ACC, the immediate precursor of ethylene. No discernible differential floral sex-dependent expression pattern was observed for this gene. The CitACS3 gene is expressed in open flowers and in young staminate floral buds (male or hermaphrodite), but not in female flowers. CitACS3 is also up-regulated by ACC, and is likely to be involved in ethylene-regulated anther development. The expression of CitACS2 was not detected in vegetative or reproductive organs but was up-regulated by auxin. CitACS4 transcript was not detected under our experimental conditions. Restriction fragment length polymorphism (RFLP) and sequence tagged site (STS) marker analyses of the CitACS genes showed polymorphism among and within the different Citrullus groups, including watermelon cultivars, Citrullus lanatus var. lanatus, the central subspecies Citrullus lanatus var. citroides, and the desert species Citrullus colocynthis (L).

  11. Transcriptomic analysis of tomato carpel development reveals alterations in ethylene and gibberellin synthesis during pat3/pat4 parthenocarpic fruit set

    Directory of Open Access Journals (Sweden)

    Pascual Laura

    2009-05-01

    Full Text Available Abstract Background Tomato fruit set is a key process that has a great economic impact on crop production. We employed the Affymetrix GeneChip Tomato Genome Array to compare the transcriptome of a non-parthenocarpic line, UC82, with that of the parthenocarpic line RP75/59 (pat3/pat4 mutant. We analyzed the transcriptome under normal conditions as well as with forced parthenocarpic development in RP75/59, emasculating the flowers 2 days before anthesis. This analysis helps to understand the fruit set in tomato. Results Differentially expressed genes were extracted with maSigPro, which is designed for the analysis of single and multiseries time course microarray experiments. 2842 genes showed changes throughout normal carpel development and fruit set. Most of them showed a change of expression at or after anthesis. The main differences between lines were concentrated at the anthesis stage. We found 758 genes differentially expressed in parthenocarpic fruit set. Among these genes we detected cell cycle-related genes that were still activated at anthesis in the parthenocarpic line, which shows the lack of arrest in the parthenocarpic line at anthesis. Key genes for the synthesis of gibberellins and ethylene, which were up-regulated in the parthenocarpic line were also detected. Conclusion Comparisons between array experiments determined that anthesis was the most different stage and the key point at which most of the genes were modulated. In the parthenocarpic line, anthesis seemed to be a short transitional stage to fruit set. In this line, the high GAs contends leads to the development of a parthenocarpic fruit, and ethylene may mimic pollination signals, inducing auxin synthesis in the ovary and the development of a jelly fruit.

  12. Transcriptomic analysis of tomato carpel development reveals alterations in ethylene and gibberellin synthesis during pat3/pat4 parthenocarpic fruit set.

    Science.gov (United States)

    Pascual, Laura; Blanca, Jose M; Cañizares, Joaquin; Nuez, Fernado

    2009-05-29

    Tomato fruit set is a key process that has a great economic impact on crop production. We employed the Affymetrix GeneChip Tomato Genome Array to compare the transcriptome of a non-parthenocarpic line, UC82, with that of the parthenocarpic line RP75/59 (pat3/pat4 mutant). We analyzed the transcriptome under normal conditions as well as with forced parthenocarpic development in RP75/59, emasculating the flowers 2 days before anthesis. This analysis helps to understand the fruit set in tomato. Differentially expressed genes were extracted with maSigPro, which is designed for the analysis of single and multiseries time course microarray experiments. 2842 genes showed changes throughout normal carpel development and fruit set. Most of them showed a change of expression at or after anthesis. The main differences between lines were concentrated at the anthesis stage. We found 758 genes differentially expressed in parthenocarpic fruit set. Among these genes we detected cell cycle-related genes that were still activated at anthesis in the parthenocarpic line, which shows the lack of arrest in the parthenocarpic line at anthesis. Key genes for the synthesis of gibberellins and ethylene, which were up-regulated in the parthenocarpic line were also detected. Comparisons between array experiments determined that anthesis was the most different stage and the key point at which most of the genes were modulated. In the parthenocarpic line, anthesis seemed to be a short transitional stage to fruit set. In this line, the high GAs contends leads to the development of a parthenocarpic fruit, and ethylene may mimic pollination signals, inducing auxin synthesis in the ovary and the development of a jelly fruit.

  13. Transient gibberellin application promotes Arabidopsis thaliana hypocotyl cell elongation without maintaining transverse orientation of microtubules on the outer tangential wall of epidermal cells

    KAUST Repository

    Sauret-Güeto, Susanna

    2011-11-25

    The phytohormone gibberellin (GA) promotes plant growth by stimulating cellular expansion. Whilst it is known that GA acts by opposing the growth-repressing effects of DELLA proteins, it is not known how these events promote cellular expansion. Here we present a time-lapse analysis of the effects of a single pulse of GA on the growth of Arabidopsis hypocotyls. Our analyses permit kinetic resolution of the transient growth effects of GA on expanding cells. We show that pulsed application of GA to the relatively slowly growing cells of the unexpanded light-grown Arabidopsis hypocotyl results in a transient burst of anisotropic cellular growth. This burst, and the subsequent restoration of initial cellular elongation rates, occurred respectively following the degradation and subsequent reappearance of a GFP-tagged DELLA (GFP-RGA). In addition, we used a GFP-tagged α-tubulin 6 (GFP-TUA6) to visualise the behaviour of microtubules (MTs) on the outer tangential wall (OTW) of epidermal cells. In contrast to some current hypotheses concerning the effect of GA on MTs, we show that the GA-induced boost of hypocotyl cell elongation rate is not dependent upon the maintenance of transverse orientation of the OTW MTs. This confirms that transverse alignment of outer face MTs is not necessary to maintain rapid elongation rates of light-grown hypocotyls. Together with future studies on MT dynamics in other faces of epidermal cells and in cells deeper within the hypocotyl, our observations advance understanding of the mechanisms by which GA promotes plant cell and organ growth. © 2011 Blackwell Publishing Ltd.

  14. Piezoelectric strain coefficients in La3Ga5.3Ta0.5Al0.2O14 and Ca3TaGa3Si2O14 crystals

    Directory of Open Access Journals (Sweden)

    Dmitry Irzhak

    2013-10-01

    Full Text Available Independent piezoelectric strain coefficients d11 and d14 in disordered La3Ga5.3Ta0.5Al0.2O14 (LGTA and ordered Ca3TaGa3Si2O14 (CTGS crystals of the langasite family were measured by high-resolution X-ray diffraction (HRXRD under external electric field application which causes changes in the interplanar spacing because of the reverse piezoelectric effect. The experiment showed that the piezoelectric strain coefficients can be precisely determined by measuring changes in the interplanar spacing using the optical scheme of a triple-axis X-ray diffractometer. The measured independent piezoelectric strain coefficients d11 and d14 for LGTA and CTGS crystals are d11(LGTA = 6.455 × 10−12 C/N, d14(LGTA = −5.117 × 10−12 C/N; d11(CTGS = 3.330 × 10−12 C/N, d14(CTGS = −15.835 × 10−12 C/N.

  15. Solvothermal synthesis, crystal structure, and second-order nonlinear optical properties of a new noncentrosymmetric gallium-organic framework material, [N(C3H7)4]3Ga3[C6H3(CO2)3]4

    Science.gov (United States)

    Lee, Dong Woo; Jo, Vinna; Ok, Kang Min

    2012-10-01

    A novel noncentrosymmetric (NCS) gallium-organic framework material, [N(C3H7)4]3Ga3[C6H3(CO2)3]4 (CAUMOF-11) has been synthesized by a solvothermal reaction using Ga(NO3)3·xH2O, 1,3,5-C6H3(CO2H)3, N(C3H7)4Cl, HNO3, and HCON(CH3)2 at 180 °C. The structure of the reported material has been determined by single-crystal X-ray diffraction. CAUMOF-11 has an anionic three-dimensional framework with aligned four-coordinate GaO4 tetrahedra and 1,3,5-benzenetricarboxylate groups. Tetrapropylammonim cations reside within the channel and maintain the charge balance. Detailed structural analyses with full characterization including infrared spectroscopy, thermogravimetric analysis, elemental analysis, ion-exchange reactions, topotactic decomposition, and gas adsorption experiments are reported. Powder second-harmonic generating (SHG) measurements on CAUMOF-11, using 1064 nm radiation, exhibit SHG efficiency of 15 times that of α-SiO2 and the material is phase-matchable (type-1).

  16. A novel gallium arsenate organically templated by propane-1,3-diyldiammonium with a ULM-3-type open framework: [Ga3(AsO4)3(OH)F]-(C3H12N2) x H2O.

    Science.gov (United States)

    Loiseau, Thierry; Ferey, Gerard

    2004-03-01

    Crystals of the title oxyfluorinated gallium arsenate, viz. tris(arsenato)fluorohydroxotrigallium propane-1,3-diyldiammonium monohydrate, were synthesized hydrothermally at 453 K under autogenous pressure, using 1,3-diaminopropane as the structure-directing agent. The solid crystallizes in the orthorhombic system and its structure was determined from single-crystal X-ray diffraction analysis. The structure is similar to that of gallium or aluminium phosphates with the ULM-3 structural type and is built up from a three-dimensional anionic framework composed of corner-linked hexameric Ga3(AsO4)3(OH)F units. The Ga atoms have an octahedral [GaO4(OH)F] or trigonal-bipyramidal [GaO4(OH) and GaO4F] coordination. These units are connected to one another and to the tetrahedral AsO4 groups via OH or F bridges. The three-dimensional framework contains ten-ring channels along [010], crosslinked by eight-ring channels along [110] and [110]. The diprotonated organic species and water molecules reside within the ten-ring channels. The cation is linked to the framework via an N-H...F hydrogen bond. A strong N-H...O hydrogen bond links the cation and the water molecule.

  17. Tungsten/molybdenum thin films for application as interdigital transducers on high temperature stable piezoelectric substrates La3Ga5SiO14 and Ca3TaGa3Si2O14

    International Nuclear Information System (INIS)

    Rane, Gayatri K.; Menzel, Siegfried; Seifert, Marietta; Gemming, Thomas; Eckert, Jürgen

    2015-01-01

    Highlights: • Refractory metals as IDT material for surface acoustic wave based high temperature sensors. • Multilayer stacking in order to obtain low electrical resistivity and for tuning residual stress. • New piezoelectric substrate for high temperature applications. • High thermal stability with improved interfacial structure of multilayer films. - Abstract: Sputter-deposited single, bi- and multilayers of W and Mo on Si substrate and high temperature stable piezoelectric substrates La 3 Ga 5 SiO 14 (LGS) and Ca 3 TaGa 3 Si 2 O 14 (CTGS) have been studied as electrode material for high temperature applications of surface acoustic wave (SAW) devices up to 800 °C. We show for the first time that the film resistivity lowers with decreasing the individual layer thickness of W in the W/Mo multilayer stack. This has been attributed to the low electron mean free path of W of about ∼4 nm as well as low electron scattering of the electrons at the W–Mo interface as a result of the formation of coherent interfaces. The stability of the films on Si and CTGS has been demonstrated up to 800 °C while the films on the LGS substrate fail already at 600 °C due to the inherent instability of the LGS substrate under vacuum annealing.

  18. A new RNASeq-based reference transcriptome for sugar beet and its application in transcriptome-scale analysis of vernalization and gibberellin responses

    Science.gov (United States)

    2012-01-01

    Background Sugar beet (Beta vulgaris sp. vulgaris) crops account for about 30% of world sugar. Sugar yield is compromised by reproductive growth hence crops must remain vegetative until harvest. Prolonged exposure to cold temperature (vernalization) in the range 6°C to 12°C induces reproductive growth, leading to bolting (rapid elongation of the main stem) and flowering. Spring cultivation of crops in cool temperate climates makes them vulnerable to vernalization and hence bolting, which is initiated in the apical shoot meristem in processes involving interaction between gibberellin (GA) hormones and vernalization. The underlying mechanisms are unknown and genome scale next generation sequencing approaches now offer comprehensive strategies to investigate them; enabling the identification of novel targets for bolting control in sugar beet crops. In this study, we demonstrate the application of an mRNA-Seq based strategy for this purpose. Results There is no sugar beet reference genome, or public expression array platforms. We therefore used RNA-Seq to generate the first reference transcriptome. We next performed digital gene expression profiling using shoot apex mRNA from two sugar beet cultivars with and without applied GA, and also a vernalized cultivar with and without applied GA. Subsequent bioinformatics analyses identified transcriptional changes associated with genotypic difference and experimental treatments. Analysis of expression profiles in response to vernalization and GA treatment suggested previously unsuspected roles for a RAV1-like AP2/B3 domain protein in vernalization and efflux transporters in the GA response. Conclusions Next generation RNA-Seq enabled the generation of the first reference transcriptome for sugar beet and the study of global transcriptional responses in the shoot apex to vernalization and GA treatment, without the need for a reference genome or established array platforms. Comprehensive bioinformatic analysis identified

  19. Internode length in Pisum. Gene na may block gibberellin synthesis between ent-7. cap alpha. -hydroxykaurenoic acid and biggerellin A/sub 12/-aldehyde. [Pisum sativum

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, T.J.; Reid, J.B.

    1987-04-01

    The elongation response of the gibberellin (GA) deficient genotypes na, ls, and lh of peas (Pisum sativum L.) to a range of GA-precursors was examined. Plants possessing gene na did not respond to precursors in the GA biosynthetic pathway prior to GA/sub 12/-aldehyde. In contrast, plants possessing lh and ls responded as well as wild-type plants (dwarfed with AMO-1618) to these compounds. The results suggest that GA biosynthesis is blocked prior to ent-kaurene in the lh and ls mutants and between ent-7..cap alpha..-hydroxykaurenoic acid and GA/sub 12/-aldehyde in the na mutant. Feeds of ent(/sup 3/H)kaurenoic acid and (/sup 2/H)GA/sub 12/-aldehyde to a range of genotypes supported the above conclusions. The na line WL1766 was shown by gas chromatography-mass spectrometry (GC-MS) to metabolize(/sup 2/H)GA/sub 12/-aldehyde to a number of (/sup 2/H)C/sub 19/-GAs including GA/sub 1/. However, there was no indication in na genotypes for the metabolism of ent-(/sup 3/H)kaurenoic acid to these GAs. In contrast, the expanding shoot tissue of all Na genotypes examined metabolized ent-(/sup 3/H)kaurenoic acid to radioactive compounds that co-chromatographed with GA/sub 1/, GA/sub 8/, GA/sub 20/, and GA/sub 29/. However, insufficient material was present for unequivocal identification of the metabolites. The radioactive profiles from HPLC of extracts of the node treated with ent-(/sup 3/H)kaurenoic acid were similar for both Na and na plants and contained ent-16..cap alpha..,17-dihydroxykaurenoic acid and ent-6..cap alpha..,7..cap alpha..,16..beta..,17-tetrahydroxykaurenoic acid (both characterized by GC-MS), suggesting that the metabolites arose from side branches of the main GA-biosynthetic pathway. Thus, both Na and na plants appear capable of ent-7..cap alpha..-hydroxylation.

  20. Aplicação de ácido giberélico (GA3 e anatomia da epiderme foliar visando à detecção de variantes somaclonais de bananeira Musa sp. Colla cv. Prata-anã (Musaceae Gibberellic acid (GA3 and anatomy of the leaf epidermises to detect somaclonal variants of the banana tree Musa sp. Colla cv. Prata-anã (Musaceae

    Directory of Open Access Journals (Sweden)

    Janaína de Oliveira Costa Silva

    2010-03-01

    Full Text Available A micropropagação de indivíduos do gênero Musa vem sendo aplicada em larga escala para obtenção de mudas de qualidade fitossanitária. O cultivo in vitro pode levar a ocorrência de variação somaclonal que pode acarretar em prejuízos aos produtores. Atualmente, a diferenciação das plantas variantes somaclonais é possível somente quando as mesmas encontram-se em condições de campo, mediante crescimento exagerado, conhecido como gigantismo. Mutantes para a produção de giberelina apresentaram fenótipo anão e esta mutação já foi revertida com a aplicação de ácido giberélico exógeno. A anatomia de plântulas cultivadas in vitro e ex vitro fornece informações que podem auxiliar na melhoria das técnicas de micropropagação e na sua seleção precoce. Objetivou-se verificar a diferenciação das estruturas anatômica entre plantas normais e variantes somaclonais. Para tal, utilizaram-se folhas de 'Prata-anã' cultivadas in vitro, em fase de aclimatização e no campo após a constatação da variação somaclonal. Secções paradérmicas foram realizadas para avaliação do complexo estomático. Secções transversais foram realizadas para medições da espessura das faces adaxial e abaxial da epiderme, medições dos parênquimas clorofilianos e da nervura central. Os resultados permitiram verificar diferenças estruturais das plantas ao longo das fases de cultivo. Foi possível também determinar marcadores anatômicos baseados no diâmetro da nervura central e na hipoderme inferior que permiti distinguir as plantas normais das variantes somaclonais.Micropropagation of Musa plants is applied on a wide scale in order to obtain plantlets with high sanitary quality. In vitro cultivation may lead to somaclonal variation that can cause harm the producers. Currently, differentiation of somaclonal variants is possible only in the field based on the exaggerated growth of the plants. Mutants for gibberellin production are dwarfed

  1. Rice black streaked dwarf virus P7-2 forms a SCF complex through binding to Oryza sativa SKP1-like proteins, and interacts with GID2 involved in the gibberellin pathway.

    Science.gov (United States)

    Tao, Tao; Zhou, Cui-Ji; Wang, Qian; Chen, Xiang-Ru; Sun, Qian; Zhao, Tian-Yu; Ye, Jian-Chun; Wang, Ying; Zhang, Zong-Ying; Zhang, Yong-Liang; Guo, Ze-Jian; Wang, Xian-Bing; Li, Da-Wei; Yu, Jia-Lin; Han, Cheng-Gui

    2017-01-01

    As a core subunit of the SCF complex that promotes protein degradation through the 26S proteasome, S-phase kinase-associated protein 1 (SKP1) plays important roles in multiple cellular processes in eukaryotes, including gibberellin (GA), jasmonate, ethylene, auxin and light responses. P7-2 encoded by Rice black streaked dwarf virus (RBSDV), a devastating viral pathogen that causes severe symptoms in infected plants, interacts with SKP1 from different plants. However, whether RBSDV P7-2 forms a SCF complex and targets host proteins is poorly understood. In this study, we conducted yeast two-hybrid assays to further explore the interactions between P7-2 and 25 type I Oryza sativa SKP1-like (OSK) proteins, and found that P7-2 interacted with eight OSK members with different binding affinity. Co-immunoprecipitation assay further confirmed the interaction of P7-2 with OSK1, OSK5 and OSK20. It was also shown that P7-2, together with OSK1 and O. sativa Cullin-1, was able to form the SCF complex. Moreover, yeast two-hybrid assays revealed that P7-2 interacted with gibberellin insensitive dwarf2 (GID2) from rice and maize plants, which is essential for regulating the GA signaling pathway. It was further demonstrated that the N-terminal region of P7-2 was necessary for the interaction with GID2. Overall, these results indicated that P7-2 functioned as a component of the SCF complex in rice, and interaction of P7-2 with GID2 implied possible roles of the GA signaling pathway during RBSDV infection.

  2. Rice black streaked dwarf virus P7-2 forms a SCF complex through binding to Oryza sativa SKP1-like proteins, and interacts with GID2 involved in the gibberellin pathway.

    Directory of Open Access Journals (Sweden)

    Tao Tao

    Full Text Available As a core subunit of the SCF complex that promotes protein degradation through the 26S proteasome, S-phase kinase-associated protein 1 (SKP1 plays important roles in multiple cellular processes in eukaryotes, including gibberellin (GA, jasmonate, ethylene, auxin and light responses. P7-2 encoded by Rice black streaked dwarf virus (RBSDV, a devastating viral pathogen that causes severe symptoms in infected plants, interacts with SKP1 from different plants. However, whether RBSDV P7-2 forms a SCF complex and targets host proteins is poorly understood. In this study, we conducted yeast two-hybrid assays to further explore the interactions between P7-2 and 25 type I Oryza sativa SKP1-like (OSK proteins, and found that P7-2 interacted with eight OSK members with different binding affinity. Co-immunoprecipitation assay further confirmed the interaction of P7-2 with OSK1, OSK5 and OSK20. It was also shown that P7-2, together with OSK1 and O. sativa Cullin-1, was able to form the SCF complex. Moreover, yeast two-hybrid assays revealed that P7-2 interacted with gibberellin insensitive dwarf2 (GID2 from rice and maize plants, which is essential for regulating the GA signaling pathway. It was further demonstrated that the N-terminal region of P7-2 was necessary for the interaction with GID2. Overall, these results indicated that P7-2 functioned as a component of the SCF complex in rice, and interaction of P7-2 with GID2 implied possible roles of the GA signaling pathway during RBSDV infection.

  3. Use of gibberellin in floriculture

    African Journals Online (AJOL)

    Yomi

    breaking chemicals on flower development of Rhododendron pulchrum Sweet and R. scabrum Don. Amsterdam. Sci. Horticult. 83: 331-337. Coll JB, Rodrigo GN, Garcia BS, Tamés RS (2001). In: Fisiología. Vegetal. Madrid: Ediciones Pirâmide. p. 566. Davies PJ (2004). Plant hormones: Biosynthesis, signal transduction,.

  4. Agrobacterium mediated transient gene silencing (AMTS in Stevia rebaudiana: insights into steviol glycoside biosynthesis pathway.

    Directory of Open Access Journals (Sweden)

    Praveen Guleria

    Full Text Available Steviol glycoside biosynthesis pathway has emerged as bifurcation from ent-kaurenoic acid, substrate of methyl erythritol phosphate pathway that also leads to gibberellin biosynthesis. However, the genetic regulation of steviol glycoside biosynthesis has not been studied. So, in present study RNA interference (RNAi based Agrobacterium mediated transient gene silencing (AMTS approach was followed. SrKA13H and three SrUGTs (SrUGT85C2, SrUGT74G1 and SrUGT76G1 genes encoding ent-kaurenoic acid-13 hydroxylase and three UDP glycosyltransferases of steviol glycoside biosynthesis pathway were silenced in Stevia rebaudiana to understand its molecular mechanism and association with gibberellins.RNAi mediated AMTS of SrKA13H and three SrUGTs has significantly reduced the expression of targeted endogenous genes as well as total steviol glycoside accumulation. While gibberellins (GA3 content was significantly enhanced on AMTS of SrUGT85C2 and SrKA13H. Silencing of SrKA13H and SrUGT85C2 was found to block the metabolite flux of steviol glycoside pathway and shifted it towards GA3 biosynthesis. Further, molecular docking of three SrUGT proteins has documented highest affinity of SrUGT76G1 for the substrates of alternate pathways synthesizing steviol glycosides. This could be a plausible reason for maximum reduction in steviol glycoside content on silencing of SrUGT76G1 than other genes.SrKA13H and SrUGT85C2 were identified as regulatory genes influencing carbon flux between steviol glycoside and gibberellin biosynthesis. This study has also documented the existence of alternate steviol glycoside biosynthesis route.

  5. Agrobacterium Mediated Transient Gene Silencing (AMTS) in Stevia rebaudiana: Insights into Steviol Glycoside Biosynthesis Pathway

    Science.gov (United States)

    Guleria, Praveen; Yadav, Sudesh Kumar

    2013-01-01

    Background Steviol glycoside biosynthesis pathway has emerged as bifurcation from ent-kaurenoic acid, substrate of methyl erythritol phosphate pathway that also leads to gibberellin biosynthesis. However, the genetic regulation of steviol glycoside biosynthesis has not been studied. So, in present study RNA interference (RNAi) based Agrobacterium mediated transient gene silencing (AMTS) approach was followed. SrKA13H and three SrUGTs (SrUGT85C2, SrUGT74G1 and SrUGT76G1) genes encoding ent-kaurenoic acid-13 hydroxylase and three UDP glycosyltransferases of steviol glycoside biosynthesis pathway were silenced in Stevia rebaudiana to understand its molecular mechanism and association with gibberellins. Methodology/Principal Findings RNAi mediated AMTS of SrKA13H and three SrUGTs has significantly reduced the expression of targeted endogenous genes as well as total steviol glycoside accumulation. While gibberellins (GA3) content was significantly enhanced on AMTS of SrUGT85C2 and SrKA13H. Silencing of SrKA13H and SrUGT85C2 was found to block the metabolite flux of steviol glycoside pathway and shifted it towards GA3 biosynthesis. Further, molecular docking of three SrUGT proteins has documented highest affinity of SrUGT76G1 for the substrates of alternate pathways synthesizing steviol glycosides. This could be a plausible reason for maximum reduction in steviol glycoside content on silencing of SrUGT76G1 than other genes. Conclusions SrKA13H and SrUGT85C2 were identified as regulatory genes influencing carbon flux between steviol glycoside and gibberellin biosynthesis. This study has also documented the existence of alternate steviol glycoside biosynthesis route. PMID:24023961

  6. Efeitos de ácido giberélico e carvão ativado no cultivo in vitro de Citrus limonia Osbeck chiPoncirus trifoliata (L. Raf Effects of gibberellic acid (GA3 and activated coal on in vitro culture of Citrus limonia Osbeck chi Poncirus trifoliata L. Raf. Embryos

    Directory of Open Access Journals (Sweden)

    Valtemir Gonçalves Ribeiro

    2000-01-01

    Full Text Available Pesquisou-se o desenvolvimento in vitro de embriões de um híbrido do cruzamento Citrus limonia Osb. chi Poncirus trifoliata (L. Raf. em meio MS, acrescido de GA3 (0,0, 0,01, 0,1 e 1,0 mg/L e carvão ativado (0,0, 0,5, 1,0 e 2,0 g/L, em todas as combinações possíveis. Após a excisão das sementes os embriões obtidos, independentemente dos estádios, foram inoculados nos respectivos meios de cultura. Cada tratamento permaneceu por 48 horas no escuro e 40 dias em sala de crescimento à temperatura de 27 ± 1ºC, com 16 horas de luminosidade. Após esse período, as plântulas foram avaliadas, considerando-se o porcentual de sobrevivência e comprimento da haste caulinar e do sistema radicular. Verificou-se que a concentação de 0,1 mg/L de GA3 interagiu antagonicamente em meio de cultivo contendo até 2,0 g/L de carvão ativado. O GA3 a 0,01 mg/L associado a concentrações de carvão ativado a partir de 0,5 g/L até 2,0 g/L, maximizou o porcentual de sobrevivência dos em- briões. Os embriões apresentaram o maior comprimento de raiz (4,5 cm e da haste caulinar (2,1 cm com carvão ativado na concentração de 0,5 g/L e 2,0 g/L, respectivamente.This work utilized fruits of a single plant obtained from the cross between Citrus limonia Osb. chi Poncirus trifoliata L. Raf. Seeds were removed and after excision, all the embryos, regardless their development stages, were inoculated in MS medium added with GA3 (0.0, 0.01, 0.1 and 1.0 mg/L and activated coal (0.0, 0.5, 1.0 and 2.0 g/L in every possible combination. These treatments remained for 48 hours in the dark and afterwards in growth room at the temperature of 27 ± 1ºC with 16 hours lighting. After 40 days, seedlings were evaluated by the lengths of the aerial part and root system and percent of survival. The concentration of 0.1 mg/L of GA3 interacts negatively in culture medium containing up to 2.0 g/L of activated coal. The concentration of 0.01 mg/L of GA3 associated to activated coal

  7. Candidacy of a chitin-inducible gibberellin-responsive gene for a major locus affecting plant height in rice that is closely linked to Green Revolution gene sd1.

    Science.gov (United States)

    Kovi, Mallikarjuna Rao; Zhang, Yushan; Yu, Sibin; Yang, Gaiyu; Yan, Wenhao; Xing, Yongzhong

    2011-09-01

    Appropriate plant height is crucial for lodging resistance to improve the rice crop yield. The application of semi-dwarf 1 led to the green revolution in the 1960s, by predominantly increasing the rice yield. However, the frequent use of single sd1 gene sources may cause genetic vulnerability to pests and diseases. Identifying useful novel semi-dwarf genes is important for the genetic manipulation of plant architecture in practical rice breeding. In this study, introgression lines derived from two parents contrasting in plant height, Zhenshan 97 and Pokkali were employed to locate a gene with a large effect on plant height by the bulk segregant analysis method. A major gene, ph1, was mapped to a region closely linked to sd1 on chromosome 1; the additive effects of ph1 were more than 50 cm on the plant height and 2 days on the heading date in a BC(4)F(2) population and its progeny. ph1 was then fine mapped to BAC AP003227. Gene annotation indicated that LOC_OS01g65990 encoding a chitin-inducible gibberellin-responsive protein (CIGR), which belongs to the GRAS family, might be the right candidate gene of ph1. Co-segregation analysis of the candidate gene-derived marker finally confirmed its identity as the candidate gene. A higher expression level of the CIGR was detected in all the tested tissues in tall plants compared to those of short plants, especially in the young leaf sheath containing elongating tissues, which indicated its importance role in regulating plant height. ph1 showed a tremendous genetic effect on plant height, which is distinct from sd1 and could be a new resource for breeding semi-dwarf varieties.

  8. Influência do ácido giberélico no desenvolvimento, produção e qualidade do fruto em cultura de pimentão (Capsicum annuum L. Influence of GA3 on the development, yield and fruit quality of pepper (Capsicum annum L. crop

    Directory of Open Access Journals (Sweden)

    A.A. Lucchesi

    1982-06-01

    Full Text Available Foi aplciado, na cultura de pimentão variedade híbrida Cascadura x Agronômico 10 G, ácido giberélico (GA3, 10, 20 e 40 ppm, pulverizado, uma, três e seis vezes, com intervalos de uma semana, iniciando-se a primeira aplicação sete dias após o transplante , com a finalidade de se estudar a influência desse fitorregulador no desenvolvimento, produção e qualidade do fruto, nessa cultura. Conclui-se que a aplicação de 10 ppm, uma semana após o transplante, resultou em maior produção; maior peso médio do fruto e relativa precocidade. A dose de 40 ppm em se is aplicações consecutivas, resultou em pequena produção, mais tardia, com as plantas mostrando maior desenvolvimento vegetativo, folhas maiores e de coloração verde amarelada.Gibberelic acid (GA3 was sprayed at concentrations of 10, 20, or 40 ppm, in one, three or six times, with one week intervals on pepper crop (C as cadura x Agronômico 10 G hyb rid , starting serven days afte r transp lanting in a field trial, to study its influence on development, yield an frut quality. The concentration of 10 ppm, applied seven days after transplanting, resulted in the highest yield , with highest mean fruit weig ht and precocity. The concentration of 40 ppm, with six applications resulted in a delayed lower yield with plants showing more ve getative growth, larger leaves and yellow green color.

  9. Influence of Plant Growth Regulators (PGRs and Planting Method on Growth and Yield in Oil Pumpkin (Cucurbita pepo var. styriaca

    Directory of Open Access Journals (Sweden)

    Shirzad SURE

    2012-05-01

    Full Text Available The effect of plant growth regulators IBA (indole butyric acid, GA3 (gibberellin and ethylene (as ethephon in two methods of planting was investigated (each method was considered as a separate experiment on morphological characters and yield of medicinal pumpkin. The experiments were carried out in a factorial trial based on completely randomized block design, with four replicates. The treatments were combined with priming and spraying with the above PGRs. The first seed priming with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm, and when seedling developed to 4 leaf stage sprayed there with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm for three times. In both planting methods, there were all of these treatments. The result showed that PGRs and planting method had significant effects on vegetative, flowering and yield characteristics including: leaf area %DM plant, number of male and female flowers per plant, number of fruit/plant, fruits fresh weight, seeds length and width, number of seed per fruit, seed yield, % seeds oil and oil yield. Hence spraying with GA3 25 ppm in four leaf stage at trellis method could be a suitable treatment for enhancing growth and yield of medicinal pumpkin.

  10. Acides gras oméga-3 alimentaires et neuropsychiatrie

    Directory of Open Access Journals (Sweden)

    Bourre Jean-Marie

    2004-07-01

    Full Text Available Omega-3 fatty acids participated in the first coherent experimental demonstration of the effect of dietary substances (nutrients on the structure and function of the brain. Experiments were first of all carried out on ex-vivo cultured brain cells, then on in vivo brain cells, finally on physiochemical, biochemical, physiological, neurosensory, and behavioural parameters. These findings indicated that the nature of polyunsaturated fatty acids (in particular omega-3 present in formula milks for infants (both premature and term determines the visual, cerebral, and intellectual abilities, as described in a recent review in OCL [1]. In view of the high omega-3 polyunsaturated fatty acid content of the brain, it is evident that these fats are involved in brain biochemistry, physiology and functionning; and thus in some neuropsychiatric diseases and in the cognitive decline of ageing. Though omega-3 fatty acids appear effective in the prevention of stress, their role as regulator of mood and libido is a matter for discussion pending experimental proof in animal and human models. Dietary omega-3 fatty acids could play a role in the prevention of some disorders including depression, as well as in dementia, particularly Alzheimer’s disease. Their direct role in major depression and bipolar disorder (manic-depressive disease and schizophrenia is not yet established. Their deficiency can prevent the renewal of membranes, and thus accelerate cerebral ageing; nonetheless, the respective roles of the vascular component on one hand (where the omega-3’s are active and the cerebral parenchyma itself on the other, have not yet been clearly resolved. The role of omega-3 in certain diseases such as dyslexia and autism is suggested. The role of omega-3 in certain diseases such as dyslexia, autism, and schizophrenia seems to suggest a problem of diet. Indeed, the insufficient dietary supply of omega-3 fatty acids in today’s French diet raises the problem of how to correct dietary habits so that the consumer will select foods that are genuinely rich in omega-3/the omega-3 family; mainly rapeseed and walnut oils on one hand and fatty fish on the other.

  11. Plant growth promotion and Penicillium citrinum

    Directory of Open Access Journals (Sweden)

    Choo Yeon-Sik

    2008-12-01

    Full Text Available Abstract Background Endophytic fungi are known plant symbionts. They produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. Coastal dunes are nutrient deficient and offer harsh, saline environment for the existing flora and fauna. Endophytic fungi may play an important role in plant survival by enhancing nutrient uptake and producing growth-promoting metabolites such as gibberellins and auxins. We screened roots of Ixeris repenes (L. A. Gray, a common dune plant, for the isolation of gibberellin secreting endophytic fungi. Results We isolated 15 endophytic fungi from the roots of Ixeris repenes and screened them for growth promoting secondary metabolites. The fungal isolate IR-3-3 gave maximum plant growth when applied to waito-c rice and Atriplex gemelinii seedlings. Analysis of the culture filtrate of IR-3-3 showed the presence of physiologically active gibberellins, GA1, GA3, GA4 and GA7 (1.95 ng/ml, 3.83 ng/ml, 6.03 ng/ml and 2.35 ng/ml, respectively along with other physiologically inactive GA5, GA9, GA12, GA15, GA19, GA20 and, GA24. The plant growth promotion and gibberellin producing capacity of IR-3-3 was much higher than the wild type Gibberella fujikuroi, which was taken as control during present study. GA5, a precursor of bioactive GA3 was reported for the first time in fungi. The fungal isolate IR-3-3 was identified as a new strain of Penicillium citrinum (named as P. citrinum KACC43900 through phylogenetic analysis of 18S rDNA sequence. Conclusion Isolation of new strain of Penicillium citrinum from the sand dune flora is interesting as information on the presence of Pencillium species in coastal sand dunes is limited. The plant growth promoting ability of this fungal strain may help in conservation and revegetation of the rapidly eroding sand dune flora. Penicillium citrinum is already known for producing mycotoxin citrinin and cellulose digesting

  12. Tip enhancement

    CERN Document Server

    Kawata, Satoshi

    2007-01-01

    This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field.·Near-field Raman scattering·Tip-enhanced Raman spectroscopy·Surface-enhanced Raman spectroscopy·Nano-photonics·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits·Single molecule detection

  13. Speech enhancement

    CERN Document Server

    Benesty, Jacob; Chen, Jingdong

    2006-01-01

    We live in a noisy world! In all applications (telecommunications, hands-free communications, recording, human-machine interfaces, etc.) that require at least one microphone, the signal of interest is usually contaminated by noise and reverberation. As a result, the microphone signal has to be ""cleaned"" with digital signal processing tools before it is played out, transmitted, or stored.This book is about speech enhancement. Different well-known and state-of-the-art methods for noise reduction, with one or multiple microphones, are discussed. By speech enhancement, we mean not only noise red

  14. Gibberellins and the cold requirement of tulip

    NARCIS (Netherlands)

    Rebers, M.

    1994-01-01

    Tulip bulbs (Tulipa gesneriana L.), with terminal buds containing a complete flower, require a period of low temperature to prepare the bud for floral stalk elongation and full flower development at subsequent higher temperatures. For the cultivar

  15. Hormone profiles in microalgae: Gibberellins and brassinosteroids

    Czech Academy of Sciences Publication Activity Database

    Stirk, W. A.; Balint, P.; Tarkowská, Danuše; Novák, Ondřej; Strnad, Miroslav; Ördög, V.; van Staden, J.

    2013-01-01

    Roč. 70, č. 2013 (2013), s. 348-353 ISSN 0981-9428 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional research plan: CEZ:AV0Z50380511 Keywords : Brassinolide * Brassinosteroids * Castasterone Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.352, year: 2013

  16. EDITORIAL: Enhancing nanolithography Enhancing nanolithography

    Science.gov (United States)

    Demming, Anna

    2012-01-01

    Lithography was invented in late 18th century Bavaria by an ambitious young playwright named Alois Senefelder. Senefelder experimented with stone, wax, water and ink in the hope of finding a way of reproducing text so that he might financially gain from a wider distribution of his already successful scripts. His discovery not only facilitated the profitability of his plays, but also provided the world with an affordable printing press that would ultimately democratize the dissemination of art, knowledge and literature. Since Senefelder, experiments in lithography have continued with a range of innovations including the use of electron beams and UV that allow increasingly higher-resolution features [1, 2]. Applications for this have now breached the limits of paper printing into the realms of semiconductor and microelectronic mechanical systems technology. In this issue, researchers demonstrate a technique for fabricating periodic features in poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) [3]. Their method combines field enhancements from silica nanospheres with laser-interference lithography to provide a means of patterning a polymer that has the potential to open the market of low-end, high-volume microelectronics. Laser-interference lithography has already been used successfully in patterning. Researchers in Korea used laser-interference lithography to generate stamps for imprinting a two-dimensional photonic crystal structure into green light emitting diodes (LEDs) [4]. The imprinted patterns comprised depressions 100 nm deep and 180 nm wide with a periodicity of 295 nm. In comparison with unpatterned LEDs, the intensity of photoluminescence was enhanced by a factor of seven in the LEDs that had the photonic crystal structures imprinted in them. The potential of exploiting field enhancements around nanostructures for new technologies has also attracted a great deal of attention. Researchers in the USA and Australia have used the field

  17. Progressivity Enhanced

    Directory of Open Access Journals (Sweden)

    Marko Hren

    2013-09-01

    Full Text Available Rather than a scientific text, the author contributes a concise memorandum from the originator of the idea who has managed the campaign for the conversion of the military barracks into a creative cluster between 1988 and 2002, when he parted ways with Metelkova due to conflicting views on the center’s future. His views shed light on a distant period of time from a perspective of a participant–observer. The information is abundantly supported by primary sources, also available online. However, some of the presented hypotheses are heavily influenced by his personal experiences of xenophobia, elitism, and predatorial behavior, which were already then discernible on the so-called alternative scene as well – so much so that they obstructed the implementation of progressive programs. The author claims that, in spite of the substantially different reality today, the myths and prejudices concerning Metelkova must be done away with in order to enhance its progressive nature. Above all, the paper calls for an objective view on internal antagonisms, mainly originating in deep class divisions between the users. These make a clear distinction between truly marginal ndividuals and the overambitious beau-bourgeois, as the author labels the large part of users of Metelkova of »his« time. On these grounds, he argues for a robust approach to ban all forms of xenophobia and self-ghettoization.

  18. The Mitochondrion-Located Protein OsB12D1 Enhances Flooding Tolerance during Seed Germination and Early Seedling Growth in Rice

    Directory of Open Access Journals (Sweden)

    Dongli He

    2014-07-01

    Full Text Available B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1. OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding.

  19. CLCuMuB βC1 Subverts Ubiquitination by Interacting with NbSKP1s to Enhance Geminivirus Infection in Nicotiana benthamiana.

    Directory of Open Access Journals (Sweden)

    Qi Jia

    2016-06-01

    Full Text Available Viruses interfere with and usurp host machinery and circumvent defense responses to create a suitable cellular environment for successful infection. This is usually achieved through interactions between viral proteins and host factors. Geminiviruses are a group of plant-infecting DNA viruses, of which some contain a betasatellite, known as DNAβ. Here, we report that Cotton leaf curl Multan virus (CLCuMuV uses its sole satellite-encoded protein βC1 to regulate the plant ubiquitination pathway for effective infection. We found that CLCuMu betasatellite (CLCuMuB βC1 interacts with NbSKP1, and interrupts the interaction of NbSKP1s with NbCUL1. Silencing of either NbSKP1s or NbCUL1 enhances the accumulation of CLCuMuV genomic DNA and results in severe disease symptoms in plants. βC1 impairs the integrity of SCFCOI1 and the stabilization of GAI, a substrate of the SCFSYL1 to hinder responses to jasmonates (JA and gibberellins (GA. Moreover, JA treatment reduces viral accumulation and symptoms. These results suggest that CLCuMuB βC1 inhibits the ubiquitination function of SCF E3 ligases through interacting with NbSKP1s to enhance CLCuMuV infection and symptom induction in plants.

  20. Roles of gibberellic acid and zinc sulphate in increasing size and ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... 2005), litchi (Stern and Gazit, 2000; Chang and Lin,. 2006), guava (El-Sharkawy et al., 2005), and pear. (Zhang et al., 2007). In all species so far studied, gibberellins had the potential for increasing fruit size. The beneficial effects of Gibberellic acid (GA3) and nutrient elements sprays specially zinc on yield ...

  1. In vitro vegetative growth and flowering of olive tree in response to ...

    African Journals Online (AJOL)

    The phytohormone gibberellin is involved in the regulation of many physiological process including flower induction and shoot growth. In this study, gibberellic acid (GA3) was used in order to induce the reversion of olive tree vegetative buds towards a floral ones in vitro. For this, six varieties (Marsaline, Chemchali, ...

  2. Exogenous application of plant growth regulators increased the total ...

    African Journals Online (AJOL)

    The effects of plant growth regulators (PGRs) were studied on growth, total flavonoid, gibberellins (GA) and salicylic acid (SA) contents of Taraxacum officinale (dandelion), a widely used medicinal plant in Korea. All the four PGRs used; gibberellic acid (GA3), kinetin (Kn), salicylic acid (SA) and ethephon (2- ...

  3. Produção de mudas de maracujazeiro-doce com o uso de biorregulador Sweet passion fruit seedlings production with growth regulator spraying

    Directory of Open Access Journals (Sweden)

    Sarita Leonel

    2005-04-01

    Full Text Available Foram avaliados os efeitos de dosagens de biorregulador (GA3 na emergência e crescimento de plantas jovens de maracujazeiro-doce (Passiflora alata, Dryander. Os tratamentos foram realizados mediante imersão das sementes em soluções preparadas com GA3 (0; 100; 200; 300 e 400 mg/l, durante 24 horas. Através dos resultados obtidos, concluiu-se que não houve diferenças significativas entre as dosagens empregadas, sendo a porcentagem máxima de emergência (97,50% verificada no tratamento com GA3 300 mg/l, num tempo médio de 28 dias. Quando as plantas atingiram 2-3 cm de altura, receberam duas pulverizações com o biorregulador, nas bandejas de poliestireno expandido onde estavam plantadas e, posteriormente, foram transferidas para sacolas de polietileno preto, onde se efetuou mais um tratamento com o ácido giberélico. As pulverizações foram realizadas a intervalos quinzenais, com as mesmas dosagens utilizadas para a emergência das plantas. Foram avaliados a altura média de plantas, o número médio de folhas e massa seca média da parte aérea (caule e folhas e raízes, sendo que a análise dessas características evidenciou que os tratamentos realizados com o biorregulador proporcionaram incrementos significativos na altura de plantas e no número de folhas, onde os melhores resultados estiveram associados à dosagem de GA3 300 mg/l.The effects of growth regulator concentrations were evaluated for sweet passion fruit (Passiflora alata, Dryander seedling emergence and growth. The seeds were treated with gibberellin (GA3 0, 100, 200, 300 e 400 mg/l during 24 hours. The results obtained showed that there were not significance between the treatments, being the highest emergence percentage (97,50% with GA3 300 mg/l at 28 days. When the seedlings were about 2-3 cm high they were sprayed with the same treatments, at 15 days intervals between the sprayings. The plants height, leaves number, dry weights of leaves plus stems and roots were

  4. Comparative Effects of Gibberellin and Paclobutrazol on Na and K Content, Phenolic Compounds and the Activity of Some Enzymesin its Biosynthesis Pathway in Sweet Sorghum (Sorghum bicolor under Salt Stress

    Directory of Open Access Journals (Sweden)

    Amir Hosein Fhrghani

    2017-08-01

    salt–stricken plants. PBZ treatment decreased negative effects of salinity and increased potassium (K+ content in roots and its transfer from root to shoot. Whereas, translocation factor of sodium was increased about 39% by GA treatment at the presence of 150mM salt. PBZ enhanced phenol content in shoots by increasing PAL activity. Therefore, GA and PBZ improved salt tolerance by transferring some ions toward shoot and root respectively. It seemed that, PBZ has an effective role in salt resistance by increasing of root growth, phenol content and maintaining the ionic balance

  5. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  6. Mammographic Image Enhancement

    International Nuclear Information System (INIS)

    Md Saion Salikin; Asmaliza Hashim; Wan Hazlinda Ismail; Azuhar Ripin; Norriza Mohd Isa; Mak Chee Hoe

    2005-01-01

    Its main aim is to process an image by utilizing enhancement techniques so that the enhanced image is better and more suitable than the original image for specific application. The objective of the project is to enhance the mammography image by using Interactive Data Language (IDL) software with some of the selected enhancement technique. In order to obtain the best enhanced image, the mammograms with different setting are prepared and the best mammography image is selected by using manual mode with technical factors 28 kV and 56.3 mAs namely 12 mA tube current and 0.45 second time exposure. This paper highlights four enhancement techniques that are chosen and the variables of each algorithm of the techniques are determined. The enhancement techniques used are image clipping technique with image clipped 21% at low ends and 5% at high ends, filtering technique with low pass filter, unsharp masking technique by creating a mask using a low pass filter and global histogram equalization. There are 24 technique permutations produced by the four enhancement techniques chosen, according to order of the enhancement technique applied on a particular mammographic image. These technique permutations are applied to the image using IDL. The enhancement technique permutation of histogram equalization, unsharp masking technique, filtering technique and image clipping technique, that produce the best enhanced image is determined qualitatively. The results of enhancement techniques by using IDL are presented in brief in this presentation. (Author)

  7. Gibberellic and kaurenoic hybrid strigolactone mimics for seed germination of parasitic weeds.

    Science.gov (United States)

    Pereira, Rondinelle G; Cala, Antonio; Fernández-Aparicio, Mónica; Molinillo, José Mg; Boaventura, Maria Ad; Macías, Francisco A

    2017-12-01

    Parasitic weeds are widespread and cause significant losses in important crops. Their germination requires the detection of crop-derived molecules such as strigolactones. Strigolactone mimics are germination-inducing molecules with the potential to apply a suicidal germination strategy for seed bank control of parasitic weeds. The D-ring, which is instrumental in the germination process of seeds of parasitic weeds, was attached to gibberellin (GA 3 ) and kaurenoic acid as the scaffold. It was shown that indeed strigolactone mimics prepared from GA 3 and kaurenoic acid are active as stimulants when a D-ring is present; some of the mimics are as active as GR24. The starting molecules were plant hormones that had previous growth-regulating activity in other organisms and the products showed enhanced activity towards parasitic weeds. The information generated may contribute to a better understanding of the germination biochemistry of the weed species used. Further research is required in this area but it is clear that the results are promising. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Plasmon enhanced spectroscopy.

    Science.gov (United States)

    Aroca, Ricardo F

    2013-04-21

    Surface enhanced spectroscopy encompasses a broad field of linear and nonlinear optical techniques that arose with the discovery of the surface-enhanced Raman scattering (SERS) effect. SERS enabled ultrasensitive and single molecule detection with molecular fingerprint specificity, opening the door for a large variety of chemical sensing applications. Basically, from the beginning it was realized that the necessary condition for SERS to be observed was the presence of a metallic nanostructure, and with this condition, the optical enhancement found a home in the field of plasmonics. Although plasmonic practitioners claim that SERS is "the most spectacular application of plasmonics", perhaps it is more appropriate to say that the spectacular development of plasmonics is due to SERS. Here is a brief recollection from surface enhanced spectroscopy to plasmon enhanced spectroscopy.

  9. EDITORIAL: Nano-enhanced! Nano-enhanced!

    Science.gov (United States)

    Demming, Anna

    2010-08-01

    In the early 19th century, a series of engineering and scientific breakthroughs by Nicolas Léonard Sadi Carnot, James Watt and many others led to the foundations of thermodynamics and a new pedigree of mechanical designs that reset the standards of engineering efficiency. The result was the industrial revolution. In optical- and electronics- based nanotechnology research, a similarly subtle bargain is being made; we cannot alter the fact that systems have a finite response to external excitations, but what we can do is enhance that response. The promising attributes of ZnO have long been recognised; its large band gap and high exciton binding energy lend it to a number of applications from laser diodes, LEDs, optical waveguides and switches, and acousto-optic applications to sun cream. When this material is grown into nanowires and nanorods, the material gains a whole new dimension, as quantum confinement effects come into play. Discovery of the enhanced radiative recombination, which has potential for exploitation in many optical and opto-electronic applications, drove intensive research into investigating these structures and into finding methods to synthesise them with optimised properties. This research revealed further subtleties in the properties of these materials. One example is the work by researchers in the US reporting synthesis procedures that produced a yield—defined as the weight ratio of ZnO nanowires to the original graphite flakes—of 200%, and which also demonstrated, through photoluminescence analysis of nanowires grown on graphite flakes and substrates, that graphite induces oxygen vacancies during annealing, which enhances the deep-level to near-band-edge emission ratio [1]. Other one-dimensional materials that provide field emission enhancements include carbon nanotubes, and work has been performed to find ways of optimising the emission efficiency from these structures, such as through control of the emitter density [2]. One of the

  10. Ring enhancement in contrast enhancement computed tomography

    International Nuclear Information System (INIS)

    Inatsuki, Shinichi; Hayashi, Kuniaki; Miyake, Hidetoshi

    1979-01-01

    Ring enhancement was examined in 11 lesions, 61 patients, we experienced. The frequency of ring enhancement observed in cerebral abscesses and tumors and the characteristics and the differential points of each disease were obtained. The frequency of ring enhancement was 54% in metastatic cerebral tumor, 56% in glioblastoma and astrocytoma (grade III) and 100% in cerebral abscess. Glioblastoma and astrocytoma (grade III) differed from other diseases in having distorted rings with poor uniform thickness. Although there was a great similarity between the computed tomographic picture of metastatic cerebral tumor and that of cerebral abscess, the ring in cerebral abscess was clearer, thin and uniform, and the peripheral edema in cerebral abscess was weak in general. In cerebral infarct, peripheral edema and mass effect of the ring were not observed or slightly observed, if any. Considering only the characteristics of the rings, there are differences between each diseases, and differentiation seems to be possibly performed. In practice, however, it is not necessarily easy to make a differential diagnosis. Clinical results should be carefully managed. (Kumagai, M.)

  11. Enhancement of HHG yield

    International Nuclear Information System (INIS)

    Serrat, C.; Biegert, J.

    2011-01-01

    A static electric field periodically distributed in space controls and enhances the yield in high harmonic generation. The method is relatively simple to implement and allows tuning from the extreme-ultraviolet to soft X-ray. The radiation yield is selectively enhanced due to symmetry breaking induced by a static electric field on the interaction between the driving laser and the medium. The enhanced spectral region is tuned by varying the periodicity of the static electric field. Simulations predict an increase of more than two orders of magnitude for harmonics in the water window spectral range.

  12. Personal Identity in Enhancement

    Directory of Open Access Journals (Sweden)

    Jana Podroužková

    2015-09-01

    Full Text Available The aim of this paper is to introduce the concept of human enhancement, its methods and its relation to personal identity. Also several approaches to personal identity will be described. Transhumanism is a special think tank supporting human enhancement through modern technologies and some of its representatives claim, that even great changes to human organisms will not affect their personal identity. I will briefly describe the most important means of human enhancment and consider the problem of personal identity for each of them separately.

  13. Medically-enhanced normality

    DEFF Research Database (Denmark)

    Møldrup, Claus; Traulsen, Janine Morgall; Almarsdóttir, Anna Birna

    2003-01-01

    Objective: To consider public perspectives on the use of medicines for non-medical purposes, a usage called medically-enhanced normality (MEN). Method: Examples from the literature were combined with empirical data derived from two Danish research projects: a Delphi internet study and a Telebus......, to optimise economic, working and family conditions. The term "doping" does not cover or explain the use of medicines as enhancement among healthy non-athletes. Conclusion: We recommend wider use of the term medically-enhanced normality as a conceptual framework for understanding and analysing perceptions...... of what is considered rational medicine use in contemporary society....

  14. Enhanced Magnetic Model 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Magnetic Model (EMM) extends to degree and order 720, resolving magnetic anomalies down to 56 km wavelength. The higher resolution of the EMM results in...

  15. Enhanced Magnetic Model 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Magnetic Model (EMM) extends to degree and order 720, resolving magnetic anomalies down to 56 km wavelength. The higher resolution of the EMM results in...

  16. Ogallala Bedrock Data Enhancement

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set provides an enhanced estimate of the bedrock elevation of the Ogallala Aquifer in Kansas based on lithologic logs from a variety of sources. The data...

  17. Rethinking enhancement in sport.

    Science.gov (United States)

    Miah, Andy

    2006-12-01

    This article explores the arguments surrounding the use of human enhancement technologies in sport, arguing for a reconceptualization of the doping debate. First, it develops an overview and critique of the legislative structures on enhancement. Subsequently, a conceptual framework for understanding the role of technological effects in sport is advanced. Finally, two case studies (hypoxic chambers and gene transfer) receive specific attention, through which it is argued that human enhancement technologies can enrich the practice of elite sports rather than diminish them. In conclusion, it is argued that elite sports are at a pivotal moment in their history as an increasing range of enhancements makes less relevant the protection of the natural human through anti-doping.

  18. Enhanced metabolite generation

    Science.gov (United States)

    Chidambaram, Devicharan [Middle Island, NY

    2012-03-27

    The present invention relates to the enhanced production of metabolites by a process whereby a carbon source is oxidized with a fermentative microbe in a compartment having a portal. An electron acceptor is added to the compartment to assist the microbe in the removal of excess electrons. The electron acceptor accepts electrons from the microbe after oxidation of the carbon source. Other transfers of electrons can take place to enhance the production of the metabolite, such as acids, biofuels or brewed beverages.

  19. Plasmonic enhancement of electroluminescence

    Science.gov (United States)

    Guzatov, D. V.; Gaponenko, S. V.; Demir, H. V.

    2018-01-01

    Here plasmonic effect specifically on electroluminescence (EL) is studied in terms of radiative and nonradiative decay rates for a dipole near a metal spherical nanoparticle (NP). Contribution from scattering is taken into account and is shown to play a decisive role in EL enhancement owing to pronounced size-dependent radiative decay enhancement and weak size effect on non-radiative counterpart. Unlike photoluminescence where local incident field factor mainly determines the enhancement possibility and level, EL enhancement is only possible by means of quantum yield rise, EL enhancement being feasible only for an intrinsic quantum yield Q0 red-orange range only. Independently of positive effect on quantum yield, metal nanoparticles embedded in an electroluminescent device will improve its efficiency at high currents owing to enhanced overall recombination rate which will diminish manifestation of Auger processes. The latter are believed to be responsible for the known undesirable efficiency droop in semiconductor commercial quantum well based LEDs at higher current. For the same reason plasmonics can diminish quantum dot photodegradation from Auger process induced non-radiative recombination and photoionization thus opening a way to avoid negative Auger effects in emerging colloidal semiconductor LEDs.

  20. Sodium enhances indium-gallium interdiffusion in copper indium gallium diselenide photovoltaic absorbers.

    Science.gov (United States)

    Colombara, Diego; Werner, Florian; Schwarz, Torsten; Cañero Infante, Ingrid; Fleming, Yves; Valle, Nathalie; Spindler, Conrad; Vacchieri, Erica; Rey, Germain; Guennou, Mael; Bouttemy, Muriel; Manjón, Alba Garzón; Peral Alonso, Inmaculada; Melchiorre, Michele; El Adib, Brahime; Gault, Baptiste; Raabe, Dierk; Dale, Phillip J; Siebentritt, Susanne

    2018-02-26

    Copper indium gallium diselenide-based technology provides the most efficient solar energy conversion among all thin-film photovoltaic devices. This is possible due to engineered gallium depth gradients and alkali extrinsic doping. Sodium is well known to impede interdiffusion of indium and gallium in polycrystalline Cu(In,Ga)Se 2 films, thus influencing the gallium depth distribution. Here, however, sodium is shown to have the opposite effect in monocrystalline gallium-free CuInSe 2 grown on GaAs substrates. Gallium in-diffusion from the substrates is enhanced when sodium is incorporated into the film, leading to Cu(In,Ga)Se 2 and Cu(In,Ga) 3 Se 5 phase formation. These results show that sodium does not decrease per se indium and gallium interdiffusion. Instead, it is suggested that sodium promotes indium and gallium intragrain diffusion, while it hinders intergrain diffusion by segregating at grain boundaries. The deeper understanding of dopant-mediated atomic diffusion mechanisms should lead to more effective chemical and electrical passivation strategies, and more efficient solar cells.

  1. The Effect of Gibberellin on Plant Growth and Development

    Science.gov (United States)

    1960-11-04

    13tort nowdered form ~:vl •V, :Y:1 io, and .1? a:nc For fillers’" ve ’tried bil clay , f rafeVine ashes,;- - beet ’Bi*£&r, All the above...1r addition to’ grapevine ashes, Kil clay and -beet sugar may’ also be surcesrfi’llv employed, a.nd that w^ter .mey be’rsäd fcr thfi...Italian hornf plants illwdnöted Tot’ ei ^bt shbrt daW^f rcm the ^dfnent /pi v< j. - pfe -r-inination.’ "Left’s control ’leaves.? rights leaves

  2. Gibberellin Induces Diploid Pollen Formation by Interfering with Meiotic Cytokinesis.

    Science.gov (United States)

    Liu, Bing; De Storme, Nico; Geelen, Danny

    2017-01-01

    The plant hormone gibberellic acid (GA) controls many physiological processes, including cell differentiation, cell elongation, seed germination, and response to abiotic stress. In this study, we report that exogenous treatment of flowering Arabidopsis (Arabidopsis thaliana) plants with GA specifically affects the process of male meiotic cytokinesis leading to meiotic restitution and the production of diploid (2n) pollen grains. Similar defects in meiotic cell division and reproductive ploidy stability occur in Arabidopsis plants depleted of RGA and GAI, two members of the DELLA family that function as suppressor of GA signaling. Cytological analysis of the double rga-24 gai-t6 mutant revealed that defects in male meiotic cytokinesis are not caused by alterations in meiosis I (MI or meiosis II (MII) chromosome dynamics, but instead result from aberrations in the spatial organization of the phragmoplast-like radial microtubule arrays (RMAs) at the end of meiosis II. In line with a role for GA in the genetic regulation of the male reproductive system, we additionally show that DELLA downstream targets MYB33 and MYB65 are redundantly required for functional RMA biosynthesis and male meiotic cytokinesis. By analyzing the expression of pRGA::GFP-RGA in the wild-type Landsberg erecta background, we demonstrate that the GFP-RGA protein is specifically expressed in the anther cell layers surrounding the meiocytes and microspores, suggesting that appropriate GA signaling in the somatic anther tissue is critical for male meiotic cell wall formation and thus plays an important role in consolidating the male gametophytic ploidy consistency. © 2017 American Society of Plant Biologists. All Rights Reserved.

  3. Les oméga 3 : de l’alimentation animale à la nutrition humaine

    Directory of Open Access Journals (Sweden)

    Combe Nicole

    2004-01-01

    Full Text Available La dernière édition des Apports nutritionnels conseillés (ANC- éd. 2001 souligne la nécessité d’accroître la consommation d’acide alpha-linolénique (ALA. Celle-ci devrait au minimum doubler et représenter 0,8 % (par rapport à l’énergie totale contre 0,34 % actuellement. Or, l’étude Aquitaine [1] a montré que les lipides d’origine animale contribuaient à près de 75 % de l’apport alimentaire en ALA. Ainsi, parmi les stratégies envisageables pour accroître notre consommation d’ALA, sans changer fondamentalement les habitudes alimentaires des Français, on note un intérêt croissant pour augmenter la teneur en oméga 3 des produits animaux via l’alimentation de ces derniers. Quelques exemples de modification de la composition en acides gras des produits animaux sont exposés. Chez les espèces monogastriques (volaille, porc, le profil des lipides de carcasse est un bon reflet des lipides alimentaires. Ainsi, chez le porc, le niveau d’oméga 3 peut être augmenté d’un facteur 2 à 4, lorsque les animaux reçoivent dans leur alimentation de l’huile de colza, des graines de lin ou de la farine de poissons. En revanche, chez les animaux ruminants, le transfert des acides gras polyinsaturés alimentaires vers les tissus est faible en raison de l’hydrogénation qu’ils subissent dans le rumen. Certaines stratégies qui consistent à protéger ces acides gras de la biohydrogénation permettent néanmoins d’accroître le taux d’ALA dans les tissus et le lait. Ainsi, il apparaît possible d’augmenter la consommation d’oméga 3 de la population, via la consommation de produits issus d’animaux nourris avec des sources d’oméga 3. Cependant, au niveau de la production, ces changements doivent être maîtrisés \\; ils ne peuvent se faire sans un contrôle des qualités d’une part organoleptiques, en raison du degré élevé d’oxydabilité de ces acides gras, d’autre part de texture, en raison de leur caractère « fluide ».

  4. Acides gras oméga-3 et risque cardiovasculaire

    Directory of Open Access Journals (Sweden)

    Dallongeville Jean

    2010-07-01

    Full Text Available Linoleic acid (LA and alpha-linolenic acid (ALA are precursors of omega-6 and omega-3 fatty acids. Eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA are synthesized from ALA. These fatty acids play important role in various biological functions. The effects of omega-3 on cardiovascular risk factors – such as lipoprotein levels, blood pressure and glycemia – are very modest at standard low doses, significant only for large intakes. Randomized trials have shown that oils enriched in EPA and DHA have an undeniable impact on heart rhythm. Consumers of long-chain fatty acid have lower heart rates than controls. Conversely, patients with established arrhythmias do not appear to benefit from treatment with these fatty acids. The observation of food habits in population cohorts helped to defined the effects of rich in ALA, EPA, DHA on the risk of myocardial infarction, coronary heart disease and sudden death. For ALA the results are inconsistent and appropriate randomized clinical trials are still conclude. The effects of EPA and DHA are better established. The meta-analysis of cohort studies shows that consumption of omega-3 long- chain (EPA-DHA reduces total mortality, death from cardiac causes, sudden death and possibly stroke. The data from prevention trials with omega-3 long-chain showed a decrease in coronary events, including fatal, in secondary prevention. These results are relatively consistent to believe that EPA and DHA intake reduces the fatal complications of myocardial infarction. Clinical trials in primary prevention are still missing. However, the sum of evidence support the recommendation for consumption of fish, EPA and DHA in patients at high risk of coronary event.

  5. Acides gras oméga-3 et déclin cognitif : la controverse

    Directory of Open Access Journals (Sweden)

    Barberger-Gateau Pascale

    2013-03-01

    Full Text Available Basic research suggests a protective effect of the long-chain omega-3 polyunsaturated fatty acids – eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA – against brain aging. In humans, many epidemiological studies have found an inverse association between fish consumption or high blood levels of EPA and DHA, and cognitive decline or risk of dementia. However, most randomized controlled trials with EPA and/or DHA supplements have failed to show any impact on cognitive decline. This paper analyses several reasons for such inconsistent results, including the time and duration of the supplementation, the cognitive and dietary inclusion criteria, the optimal doses of EPA and DHA, the interaction with genetic polymorphisms, and the need to consider synergistic effects between nutrients as they are provided by healthy diets.

  6. Enhancing the growth and yield of Ramie (Boehmeria nivea L.) by ramie biomass waste in liquid form and gibberellic acid

    Science.gov (United States)

    Suherman, C.; Nuraini, A.; Wulandari, A. P.; Kadapi, M.

    2017-05-01

    Ramie (Boehmeria nivea L.) is one of the most important sources of natural fibre, a sustainable biomass. The growth and yield of ramie are affected by mineral nutrients. In the present study, we usedfertilizers from waste of ramie biomass in liquid form (liquid organic fertilizer, LOF) and the other treatment is by gibberellic acid (GA3). This study was to obtain the effect of treatments on enhance the growth and yield of ramie. Hence, we measure the character that related to the important parameter for biomass product of ramie. Such plant height, stem diameter, dry plant weight, and ramie fresh stem weight of ramie clone Pujon 13. This research was conducted from January 2016 to March 2016 at Research Field Ciparanje, Faculty of Agriculture, Padjadjaran University, Jatinangor, Sumedang, West Java with an altitude of about ± 750 m above sea level. The type of Soil in this area is Inceptisolsoil order and thetype of rainfall according to Schmidt and Fergusson Classification is C type. The experiment used Randomized Block Design (RBD) which consisted of eight treatments (GA and LOF) and four replications. The concentration of GA from 0, 50, 100 and 150 ppm and for concentration of LOF is 40 mlL-1. We suggested the treatment of GA 150 ppm with 40 mlL-1 LOF was the best treatment on enhancing plant height and stem fresh weight of ramie clone Pujon 13.

  7. Cholesterol Domains Enhance Transfection

    Science.gov (United States)

    Betker, Jamie L.; Kullberg, Max; Gomez, Joe; Anchordoquy, Thomas J.

    2014-01-01

    The formation of cholesterol domains in lipoplexes has been associated with enhanced serum stability and transfection rates both in cell culture and in vivo. This study utilizes the ability of saturated phosphatidylcholines to promote the formation of cholesterol domains at much lower cholesterol contents than have been utilized in previous work. The results show that lipoplexes with identical cholesterol and cationic lipid contents exhibit significantly improved transfection efficiencies when a domain is present, consistent with previous work. In addition, studies assessing transfection rates in the absence of serum demonstrate that the ability of domains to enhance transfection is not dependent on interactions with serum proteins. Consistent with this hypothesis, characterization of the adsorbed proteins composing the corona of these lipoplex formulations did not reveal a correlation between transfection and the adsorption of a specific protein. Finally, we show that the interaction with serum proteins can promote domain formation in some formulations, and thereby result in enhanced transfection only after serum exposure. PMID:23557286

  8. Human freedom and enhancement.

    Science.gov (United States)

    Heilinger, Jan-Christoph; Crone, Katja

    2014-02-01

    Ideas about freedom and related concepts like autonomy and self-determination play a prominent role in the moral debate about human enhancement interventions. However, there is not a single understanding of freedom available, and arguments referring to freedom are simultaneously used to argue both for and against enhancement interventions. This gives rise to misunderstandings and polemical arguments. The paper attempts to disentangle the different distinguishable concepts, classifies them and shows how they relate to one another in order to allow for a more structured and clearer debate. It concludes in identifying the individual underpinnings and the social conditions of choice and decision-making as particularly salient dimensions of freedom in the ethical debate about human enhancement.

  9. Biomedical enhancements as justice.

    Science.gov (United States)

    Nam, Jeesoo

    2015-02-01

    Biomedical enhancements, the applications of medical technology to make better those who are neither ill nor deficient, have made great strides in the past few decades. Using Amartya Sen's capability approach as my framework, I argue in this article that far from being simply permissible, we have a prima facie moral obligation to use these new developments for the end goal of promoting social justice. In terms of both range and magnitude, the use of biomedical enhancements will mark a radical advance in how we compensate the most disadvantaged members of society. © 2013 John Wiley & Sons Ltd.

  10. Cavity-enhanced spectroscopies

    CERN Document Server

    van Zee, Roger

    2003-01-01

    ""Cavity-Enhanced Spectroscopy"" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectr

  11. Changes of endogenous hormones in irradiated potato tubers

    International Nuclear Information System (INIS)

    Farag, S.E.A.; El-Saeid, H.M.; Abou-Hadid, A.F.

    1992-01-01

    Potato tubers Solatum tuberosum L. cv. Alpha were irradiated with 0.12 kgy and stored at room temperature. The endogenous hormones were extracted and determined using bioassay at dormant, budding and sprouting stages. The studied promoters were IAA, IAN, GA3 and Gibberellin like substances besides the inhibitors which included ABA and B-inhibitors. The results indicated that IAA was more sensitive to irradiation than IAN, GA3 but ABA was more stable than B-inhibitors during the dormancy. Irradiation decreased IAA and Gibberellin like substances and B-inhibitors but no change was observed in ABA content at dormant period. Irradiation caused a balance between promoters inhibitors at the end of tuber storage and after tubers sprouting

  12. Music Enhances Learning.

    Science.gov (United States)

    Campabello, Nicolette; De Carlo, Mary Jane; O'Neil, Jean; Vacek, Mary Jill

    An action research project implemented musical strategies to affect and enhance student recall and memory. The target population was three suburban elementary schools near a major midwestern city: (1) a kindergarten classroom contained 32-38 students; (2) a second grade classroom contained 23 students and five Individualized Education Program…

  13. Heat transfer enhancement

    International Nuclear Information System (INIS)

    Hasatani, Masanobu; Itaya, Yoshinori

    1985-01-01

    In order to develop energy-saving techniques and new energy techniques, and also most advanced techniques by making industrial equipment with high performance, heat transfer performance frequently becomes an important problem. In addition, the improvement of conventional heat transfer techniques and the device of new heat transfer techniques are often required. It is most proper that chemical engineers engage in the research and development for enhancing heat transfer. The research and development for enhancing heat transfer are important to heighten heat exchange efficiency or to cool equipment for preventing overheat in high temperature heat transfer system. In this paper, the techniques of enhancing radiative heat transfer and the improvement of radiative heat transfer characteristics are reported. Radiative heat transfer is proportional to fourth power of absolute temperature, and it does not require any heat transfer medium, but efficient heat-radiation converters are necessary. As the techniques of enhancing radiative heat transfer, the increase of emission and absorption areas, the installation of emissive structures and the improvement of radiative characteristics are discussed. (Kako, I.)

  14. Placebo can enhance creativity.

    Science.gov (United States)

    Rozenkrantz, Liron; Mayo, Avraham E; Ilan, Tomer; Hart, Yuval; Noy, Lior; Alon, Uri

    2017-01-01

    The placebo effect is usually studied in clinical settings for decreasing negative symptoms such as pain, depression and anxiety. There is interest in exploring the placebo effect also outside the clinic, for enhancing positive aspects of performance or cognition. Several studies indicate that placebo can enhance cognitive abilities including memory, implicit learning and general knowledge. Here, we ask whether placebo can enhance creativity, an important aspect of human cognition. Subjects were randomly assigned to a control group who smelled and rated an odorant (n = 45), and a placebo group who were treated identically but were also told that the odorant increases creativity and reduces inhibitions (n = 45). Subjects completed a recently developed automated test for creativity, the creative foraging game (CFG), and a randomly chosen subset (n = 57) also completed two manual standardized creativity tests, the alternate uses test (AUT) and the Torrance test (TTCT). In all three tests, participants were asked to create as many original solutions and were scored for originality, flexibility and fluency. The placebo group showed higher originality than the control group both in the CFG (pcreativity. This strengthens the view that placebo can be used not only to reduce negative clinical symptoms, but also to enhance positive aspects of cognition. Furthermore, we find that the impact of placebo on creativity can be tested by CFG, which can quantify multiple aspects of creative search without need for manual coding. This approach opens the way to explore the behavioral and neural mechanisms by which placebo might amplify creativity.

  15. Enhanced processive cellulases

    Energy Technology Data Exchange (ETDEWEB)

    Adney, William S.; Beckham, Gregg T.; Jarvis, Eric; Himmel, Michael E.; Decker, Stephen R.; Linger, Jeffrey G.; Podkaminer, Kara; Baker, John O.; Taylor, II, Larry; Xu, Qi; Singh, Arjun

    2017-06-20

    Nucleic acid sequences encoding chimeric polypeptides that exhibit enhanced cellulase activities are disclosed herein. These nucleic acids may be expressed in hosts such as fungi, which in turn may be cultured to produce chimeric polypeptides. Also disclosed are chimeric polypeptides and their use in the degradation of cellulosic materials.

  16. Teaching to Enhance Research

    Science.gov (United States)

    Harland, Tony

    2016-01-01

    In this paper, I present a conceptual argument for "teaching-led research" in which university lecturers construct courses that directly and positively influence their research, while at the same time, safeguard and enhance the student experience. A research-pedagogy for higher education considers the link between teaching and research,…

  17. Defining Human Enhancement

    DEFF Research Database (Denmark)

    Nordberg, Ana

    2017-01-01

    Emerging technologies open the prospect of extraordinary interventions on the human body. These may go beyond what is strictly necessary to sustain health and well-being. While responding to social and ethical challenges of such advances, the Law simultaneously faces the challenge of reflecting...... on the legitimacy to legislate and on whether the existing legal framework is appropriate to address the various concerns. In order to do so, it is crucial to establish clear legal definitions. Precise distinctions between interventions on the human body are intrinsically difficult to formulate. However, subject......-matter definitions are vital legal tools to determine what is currently regulated in established fields of law and whether there is room for a new legal field – Enhancement Law. This paper provides a reflection on the relevance of establishing a legal definition of human enhancement and to what extent different...

  18. Enhanced Microfluidic Electromagnetic Measurements

    Science.gov (United States)

    Giovangrandi, Laurent (Inventor); Ricco, Antonio J. (Inventor); Kovacs, Gregory (Inventor)

    2015-01-01

    Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.

  19. Superposition Enhanced Nested Sampling

    Directory of Open Access Journals (Sweden)

    Stefano Martiniani

    2014-08-01

    Full Text Available The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

  20. Surface plasmon enhanced LED

    OpenAIRE

    Vučković, Jelena; Lončar, Marko; Painter, Oskar; Scherer, Axel

    2000-01-01

    Summary form only given. We designed and fabricated an LED based on a thin semiconductor membrane (λ/2) with silver mirrors. A large spontaneous emission enhancement and a high modulation speed are obtainable due to the strong localization of the electromagnetic field in the microcavity. The coupling to surface plasmon modes which are subsequently scattered out by means of a grating is used to improve the extraction efficiency of the LED. The bottom mirror is thick and unpatterned. The top mi...

  1. Enhancing radiation biodosimetry capability

    International Nuclear Information System (INIS)

    Alok, A.; Kumar, A.; Kulshrestra, S.; Choudhary, S.; Bhagi, S.; Adhikari, J.S.; Chaudhury, N.K.

    2016-01-01

    Biodosimetry laboratories are necessary for quick and accurate assessment of absorbed radiation dose in suspected individuals for their medical management. The method is based on dicentric chromosomal assay (Gold standard). This assay is completely manual and time consuming, require skill and competency of laboratory staff. There is a necessity of more biodosimetry labs within country and networking within and at international level for enhancing medical preparedness for management of radiation emergency

  2. Enhanced pain syndromes

    Directory of Open Access Journals (Sweden)

    Evelin Diana Goldenberg Meirelles Mariano da Costa

    2008-03-01

    Full Text Available Enhanced pain syndromes have their prevalence increased withold age. Fibromyalgia, among them deserves special attention. Itscauses are still unknown. Fibromyalgia syndrome affects mainlyfemales and is characterized by generalized musculoskeletal pain,fatigue, sleep disturbances, diffuse stiffness and other psychic signsand symptoms. Diagnosis is essentially based on the 1990 AmericanCollege of Rheumatology Classifi cative Criteria. In this chapteraspects related to its treatment and prognosis are also discussed.

  3. Enhanced Attenuation: Chlorinated Organics

    Science.gov (United States)

    2008-04-01

    an electron acceptor. Common substitutes for oxygen are nitrate, sulfate, iron, carbon dioxide, and other organic compounds ( fermentation ). anoxic...that not until the analysis is focused just on the extremely bioavailable VFAs (also called “metabolic acids”: acetic, propionic, butyric , iso- and...I or Type II chlorinated solvent site, Wiedemeier et al. 1998) or if the electron donor supply is enhanced by adding fermentation substrates or

  4. Novelty enhances visual perception.

    Directory of Open Access Journals (Sweden)

    Judith Schomaker

    Full Text Available The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

  5. Novelty enhances visual perception.

    Science.gov (United States)

    Schomaker, Judith; Meeter, Martijn

    2012-01-01

    The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

  6. Sleep for cognitive enhancement

    Directory of Open Access Journals (Sweden)

    Susanne eDiekelmann

    2014-04-01

    Full Text Available Sleep is essential for effective cognitive functioning. Loosing even a few hours of sleep can have detrimental effects on a wide variety of cognitive processes such as attention, language, reasoning, decision making, learning and memory. While sleep is necessary to ensure normal healthy cognitive functioning, it can also enhance performance beyond the boundaries of the normal condition. This article discusses the enhancing potential of sleep, mainly focusing on the domain of learning and memory. Sleep is known to facilitate the consolidation of memories learned before sleep as well as the acquisition of new memories to be learned after sleep. According to a widely held model this beneficial effect of sleep relies on the neuronal reactivation of memories during sleep that is associated with sleep-specific brain oscillations (slow oscillations, spindles, ripples as well as a characteristic neurotransmitter milieu. Recent research indicates that memory processing during sleep can be boosted by (i cueing memory reactivation during sleep, (ii stimulating sleep-specific brain oscillations, and (iii targeting specific neurotransmitter systems pharmacologically. Olfactory and auditory cues can be used, for example, to increase reactivation of associated memories during post-learning sleep. Intensifying neocortical slow oscillations (the hallmark of slow wave sleep by electrical or auditory stimulation and modulating specific neurotransmitters such as noradrenaline and glutamate likewise facilitates memory processing during sleep. With this evidence in mind, this article concludes by discussing different methodological caveats and ethical issues that should be considered when thinking about using sleep for cognitive enhancement in everyday applications.

  7. Sweeteners and sweetness enhancers.

    Science.gov (United States)

    Belloir, Christine; Neiers, Fabrice; Briand, Loïc

    2017-07-01

    The current review summarizes and discusses current knowledge on sweeteners and sweetness enhancers. The perception of sweet taste is mediated by the type 1 taste receptor 2 (T1R2)/type 1 taste receptor 3 (T1R3) receptor, which is expressed in the oral cavity, where it provides input on the caloric and macronutrient contents of ingested food. This receptor recognizes all the compounds (natural or artificial) perceived as sweet by people. Sweeteners are highly chemically diverse including natural sugars, sugar alcohols, natural and synthetic sweeteners, and sweet-tasting proteins. This single receptor is also the target for developing novel sweet enhancers. Importantly, the expression of a functional T1R2/T1R3 receptor is described in numerous extraoral tissues. In this review, the physiological impact of sweeteners is discussed. Sweeteners and sweetness enhancers are perceived through the T1R2/T1R3 taste receptor present both in mouth and numerous extraoral tissues. The accumulated knowledge on sugar substitutes raises the issue of potential health effects.

  8. ICRF enhanced potentials

    International Nuclear Information System (INIS)

    Nelson, B.A.

    1987-01-01

    Ion-confining potentials in the Phaedrus tandem mirror are shown to be enhanced over Boltzmann-relations predicted values by radio-frequency (rf) waves in the ion cyclotron range of frequencies (ICRF). The ICRF enhanced potential is larger in the end cell with a lower passing density. Peak potential values decrease with increasing ion endloss current (or central cell density) for a constant rf capacitor bank voltage, and increase with increasing rf-capacitor bank voltage, for a constant ion endloss value (or central cell density). In fully axisymmetric operation, a potential peak is produced in an end cell by the central-cell rf, (with-out end-cell rf) and is found only in the end cell nearer the central-cell antenna. ICRF enhanced potentials are explained as an equilibrium between the electron-collisional filling-in rate and the electron pumping out rate provided by axial time-varying electric fields. Thermal barrier-like potential structures were found in the transition regions between the central cell and end cells, in the fully axisymmetric Phaedrus. Central-cell ICRF trapping effects combined with end-cell μΔ B forces create and pump the barrier potential wells

  9. Overexpression of SrUGT85C2 from Stevia reduced growth and yield of transgenic Arabidopsis by influencing plastidial MEP pathway.

    Science.gov (United States)

    Guleria, Praveen; Masand, Shikha; Yadav, Sudesh Kumar

    2014-04-15

    The transcript expression of a gene SrUGT85C2 has been documented for direct relation with steviol glycoside content in Stevia plant. Steviol glycoside and gibberellin biosynthetic routes are divergent branches of methyl erythritol-4 phosphate (MEP) pathway. So, SrUGT85C2 might be an influencing gibberellin content. Hence in the present study, transgenic Arabidopsis thaliana overexpressing SrUGT85C2 cDNA from Stevia rebaudiana was developed to check its effect on gibberellin accumulation and related plant growth parameters. The developed transgenics showed a noteworthy decrease of 78-83% in GA3 content. Moreover, the transgenics showed a gibberellin deficient phenotype comprising stunted hypocotyl length, reduced shoot growth and a significant fall in relative water content. Transgenics also showed 17-37 and 64-76% reduction in chlorophyll a and chlorophyll b contents, respectively. Reduction in photosynthetic pigments could be responsible for the noticed significant decrease in plant biomass. Like steviol glycoside and gibberellin biosynthesis, chlorophyll biosynthesis also occurs from the precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) of MEP pathway in the plastids. The observed downregulated expression of genes encoding MEP pathway enzymes geranyl geranyl diphosphate synthase (GGDPS), copalyl diphosphate synthase (CDPS), kaurenoic acid oxidase (KAO), chlorophyll synthetase and chlorophyll a oxygenase in transgenics overexpressing SrUGT85C2 might be responsible for the reduction in gibberellins as well as chlorophyll. This study has documented for the first time the regulatory role of SrUGT85C2 in the biosynthesis of steviol glycoside, gibberellins and chlorophyll. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. ICT Enhanced Buildings Potentials

    DEFF Research Database (Denmark)

    Christiansson, Per

    2007-01-01

    component systems that are accessed and integrated in the real world of building use in different contexts. The ICT systems may be physically or virtually embedded in the building. Already in 1982 AT&T established the 'intelligent buildings', IB, concept due to marketing reasons and the Informart building...... with focus on virtual building models support, new services and user environment definitions and development, virtual spaces and augmented reality, intelligent building components, application ontologies, and ICT systems integration to illustrate ICT enhanced buildings potentials and R&D needs.  ...

  11. Helping faculty enhance scholarship.

    Science.gov (United States)

    Hawranik, Pamela; Thorpe, Karran M

    2008-04-01

    Nurse educators face a myriad of challenges (e.g., changing student populations, increased demand for the use of technology, faculty shortages, and facilitating the development of self-confidence and competence in students) as they endeavor to enhance scholarship and quality in nursing education. Scholarship encompasses four separate but integrated elements (i.e., discovery, integration, application, and teaching) that need to be instilled in nursing students to prepare them for diverse roles in the profession of nursing. Implications for nurse educators relate to creating curricula that support scholarship, technological and interprofessional opportunities, and strategies for socializing students into scholarship.

  12. Enhancing LAN performance

    CERN Document Server

    Held, Gilbert

    2004-01-01

    Enhancing LAN Performance, Fourth Edition explains how to connect geographically separated LANs with appropriate bandwidth, the issues to consider when weighing the use of multiport or dualport devices, how to estimate traffic for new networks, the effects of configuration changes on the performance of Ethernet and Token Ring networks, the design of switch-based networks that prevent traffic bottlenecks, and other critical topics. It provides the tools to address these issues in relation to specific network requirements. This volume develops mathematical models of various LAN performance issue

  13. Acoustically enhanced heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: tan.ming.kwang@monash.edu [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)

    2016-01-15

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  14. Telemetry-Enhancing Scripts

    Science.gov (United States)

    Maimone, Mark W.

    2009-01-01

    Scripts Providing a Cool Kit of Telemetry Enhancing Tools (SPACKLE) is a set of software tools that fill gaps in capabilities of other software used in processing downlinked data in the Mars Exploration Rovers (MER) flight and test-bed operations. SPACKLE tools have helped to accelerate the automatic processing and interpretation of MER mission data, enabling non-experts to understand and/or use MER query and data product command simulation software tools more effectively. SPACKLE has greatly accelerated some operations and provides new capabilities. The tools of SPACKLE are written, variously, in Perl or the C or C++ language. They perform a variety of search and shortcut functions that include the following: Generating text-only, Event Report-annotated, and Web-enhanced views of command sequences; Labeling integer enumerations with their symbolic meanings in text messages and engineering channels; Systematic detecting of corruption within data products; Generating text-only displays of data-product catalogs including downlink status; Validating and labeling of commands related to data products; Performing of convenient searches of detailed engineering data spanning multiple Martian solar days; Generating tables of initial conditions pertaining to engineering, health, and accountability data; Simplified construction and simulation of command sequences; and Fast time format conversions and sorting.

  15. Diablo Canyon ECCS enhancements

    International Nuclear Information System (INIS)

    Lin, A.; Lee, T.P.; Walter, L.E.

    2004-01-01

    Diablo Canyon Power Plant (DCPP) operated by Pacific Gas and Electric Co. (PG and E) is a Westinghouse designed four loop plant. In recent years, several issues were identified regarding the compliance of the Emergency Core Cooling System (ECCS) surveillance tests to the ECCS analyses assumptions. These concerns are related mostly to the High Head Safety Injection (HHSI) and the Intermediate Head Safety Injection (IHSI) systems where the injection line throttle valves are adjusted during outage surveillance testing to ensure compliance with the Technical Specifications (TS). To resolve all of the identified issues PG and E performed an ECCS reanalysis and upgraded the ECCS surveillance test program and also had Westinghouse perform a containment reanalysis using their latest model. As a result of these plant specific enhancement efforts, DCPP widened the operating window for TS surveillance testing, lowered the ECCS pumps' acceptance performance curves, and re-gained Peak Clad Temperature (PCT) and containment peak pressure margins. These enhancements are generically applicable to other plants and are addressed in this paper. (author)

  16. Acoustically enhanced heat transport

    Science.gov (United States)

    Ang, Kar M.; Yeo, Leslie Y.; Friend, James R.; Hung, Yew Mun; Tan, Ming K.

    2016-01-01

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ˜ 106 Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξs ˜ 10-9 m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξs ˜ 10-8 m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10-8 m with 106 Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  17. Ultrasound-enhanced electrospinning.

    Science.gov (United States)

    Nieminen, Heikki J; Laidmäe, Ivo; Salmi, Ari; Rauhala, Timo; Paulin, Tor; Heinämäki, Jyrki; Hæggström, Edward

    2018-03-13

    Electrospinning is commonly used to produce polymeric nanofibers. Potential applications for such fibers include novel drug delivery systems, tissue engineering scaffolds, and filters. Electrospinning, however, has shortcomings such as needle clogging and limited ability to control the fiber-properties in a non-chemical manner. This study reports on an orifice-less technique that employs high-intensity focused ultrasound, i.e. ultrasound-enhanced electrospinning. Ultrasound bursts were used to generate a liquid protrusion with a Taylor cone from the surface of a polymer solution of polyethylene oxide. When the polymer was charged with a high negative voltage, nanofibers jetted off from the tip of the protrusion landed on an electrically grounded target held at a constant distance from the tip. Controlling the ultrasound characteristics permitted physical modification of the nanofiber topography at will without using supplemental chemical intervention. Possible applications of tailor-made fibers generated by ultrasound-enhanced electrospinning include pharmaceutical controlled-release applications and biomedical scaffolds with spatial gradients in fiber thickness and mechanical properties.

  18. Transient Enhanced Diffusion

    Science.gov (United States)

    Gossmann, Hans-Joachim L.

    1996-03-01

    Ion implantation is the standard method for dopant introduction during integrated circuit manufacturing, determining crucial device characteristics. Implantation creates point-defects, such as Si self-interstitials and vacancies, far in excess of equilibrium concentrations. Since the diffusion of common dopants involves Si point defects, the interaction of damage and dopants during subsequent annealing steps leads to the phenomenon known as "transient enhanced diffusion" (TED): The dopant diffusivities are enhanced, possibly by many orders of magnitude. The enhancement is transient since the intrinsic defects eventually diffuse into the bulk or annihilate at the surface. The desired specific dopant profile of the device is thus the result of a complex reaction, involving the creation of damage and its spatial distribution, diffusion, and interaction of the point defects among themselves and with interfaces and other defects. As device dimensions shrink and experiments become more and more expensive, the capability to predict these kinds of non-equilibrium phenomena accurately becomes crucial to Si technology development. In our experiments to extract physical mechanisms and parameters of TED we use the method of sharp B- and Sb doping spikes to track interstitial and vacancy concentrations as a function of depth during processing. Thus we gain sensitivity to small diffusion distances (low temperatures) and separate the damaged region from the region of the interaction with dopants. In addition, our method yields directly the actual point defect diffusivity. Although an ion implant initially produces Frenkel pairs, Monte-carlo simulations show that the vacancies annihilate quickly. The excess interstitials, roughly one for each implanted ion coalesce into 311defects. The subsequent evaporation of interstitials from 311ś drives TED. Si interstitial diffusion is influenced by carbon-related traps and we will demonstrate that this finding reconciles quantitatively a

  19. Biomass energy resource enhancement

    International Nuclear Information System (INIS)

    Grover, P.D.

    1995-01-01

    The demand for energy in developing countries is expected to increase to at least three times its present level within the next 25 years. If this demand is to be met by fossil fuels, an additional 2 billion tonnes of crude oil or 3 billion tonnes of coal would be needed every year. This consumption pattern, if allowed to proceed, would add 10 billion tonnes of CO 2 , to the global atmosphere each year, with its attendant risk of global warming. Therefore, just for our survival, it is imperative to progressively replace fossil fuels by biomass energy resources and to enhance the efficiency of use of the latter. Biomass is not only environmentally benign but is also abundant. It is being photosynthesised at the rate of 200 billion tonnes of carbon every year, which is equivalent to 10 times the world's present demand for energy. Presently, biomass energy resources are highly under-utilised in developing countries; when they are used it is through combustion, which is inefficient and causes widespread environmental pollution with its associated health hazards. Owing to the low bulk density and high moisture content of biomass, which make it difficult to collect, transport and store, as well as its ash-related thermochemical properties, its biodegradability and seasonal availability, the industrial use of biomass is limited to small and (some) medium-scale industries, most of which are unable to afford efficient but often costly energy conversion systems. Considering these constraints and the need to enhance the use base, biomass energy technologies appropriate to developing countries have been identified. Technologies such as briquetting and densification to upgrade biomass fuels are being adopted as conventional measures in some developing countries. The biomass energy base can be enhanced only once these technologies have been shown to be viable under local conditions and with local raw materials, after which they will multiply on their own, as has been the case

  20. Novel medical image enhancement algorithms

    Science.gov (United States)

    Agaian, Sos; McClendon, Stephen A.

    2010-01-01

    In this paper, we present two novel medical image enhancement algorithms. The first, a global image enhancement algorithm, utilizes an alpha-trimmed mean filter as its backbone to sharpen images. The second algorithm uses a cascaded unsharp masking technique to separate the high frequency components of an image in order for them to be enhanced using a modified adaptive contrast enhancement algorithm. Experimental results from enhancing electron microscopy, radiological, CT scan and MRI scan images, using the MATLAB environment, are then compared to the original images as well as other enhancement methods, such as histogram equalization and two forms of adaptive contrast enhancement. An image processing scheme for electron microscopy images of Purkinje cells will also be implemented and utilized as a comparison tool to evaluate the performance of our algorithm.

  1. Surface enhanced Raman scattering

    CERN Document Server

    Furtak, Thomas

    1982-01-01

    In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de­ veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would l...

  2. Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jeanloz, R. [The MITRE Corporation, McLean, VA (United States); Stone, H. [The MITRE Corporation, McLean, VA (United States); et al.

    2013-12-31

    DOE, through the Geothermal Technologies Office (GTO) within the Office of Energy Efficiency and Renewable Energy, requested this study, identifying a focus on: i) assessment of technologies and approaches for subsurface imaging and characterization so as to be able to validate EGS opportunities, and ii) assessment of approaches toward creating sites for EGS, including science and engineering to enhance permeability and increase the recovery factor. Two days of briefings provided in-depth discussion of a wide range of themes and challenges in EGS, and represented perspectives from industry, government laboratories and university researchers. JASON also contacted colleagues from universities, government labs and industry in further conversations to learn the state of the field and potential technologies relevant to EGS.

  3. Surface enhanced thermo lithography

    KAUST Repository

    Coluccio, Maria Laura

    2017-01-13

    We used electroless deposition to fabricate clusters of silver nanoparticles (NPs) on a silicon substrate. These clusters are plasmonics devices that induce giant electromagnetic (EM) field increments. When those EM field are absorbed by the metal NPs clusters generate, in turn, severe temperature increases. Here, we used the laser radiation of a conventional Raman set-up to transfer geometrical patterns from a template of metal NPs clusters into a layer of thermo sensitive Polyphthalaldehyde (PPA) polymer. Temperature profile on the devices depends on specific arrangements of silver nanoparticles. In plane temperature variations may be controlled with (i) high nano-meter spatial precision and (ii) single Kelvin temperature resolution on varying the shape, size and spacing of metal nanostructures. This scheme can be used to generate strongly localized heat amplifications for applications in nanotechnology, surface enhanced thermo-lithography (SETL), biology and medicine (for space resolved cell ablation and treatment), nano-chemistry.

  4. Optically enhanced acoustophoresis

    Science.gov (United States)

    McDougall, Craig; O'Mahoney, Paul; McGuinn, Alan; Willoughby, Nicholas A.; Qiu, Yongqiang; Demore, Christine E. M.; MacDonald, Michael P.

    2017-08-01

    Regenerative medicine has the capability to revolutionise many aspects of medical care, but for it to make the step from small scale autologous treatments to larger scale allogeneic approaches, robust and scalable label free cell sorting technologies are needed as part of a cell therapy bioprocessing pipeline. In this proceedings we describe several strategies for addressing the requirements for high throughput without labeling via: dimensional scaling, rare species targeting and sorting from a stable state. These three approaches are demonstrated through a combination of optical and ultrasonic forces. By combining mostly conservative and non-conservative forces from two different modalities it is possible to reduce the influence of flow velocity on sorting efficiency, hence increasing robustness and scalability. One such approach can be termed "optically enhanced acoustophoresis" which combines the ability of acoustics to handle large volumes of analyte with the high specificity of optical sorting.

  5. Wedgelet Enhanced Appearance Models

    DEFF Research Database (Denmark)

    Darkner, Sune; Larsen, Rasmus; Stegmann, Mikkel Bille

    2004-01-01

    Statistical region-based segmentation methods such as the Active Appearance Model (AAM) are used for establishing dense correspondences in images based on learning the variation in shape and pixel intensities in a training set. For low resolution 2D images correspondences can be recovered reliably...... in real-time. However, as resolution increases this becomes infeasible due to excessive storage and computational requirements. In this paper we propose to reduce the textural components by modelling the coefficients of a wedgelet based regression tree instead of the original pixel intensities....... The wedgelet regression trees employed are based on triangular domains and estimated using cross validation. The wedgelet regression trees are functional descriptions of the intensity information and serve to 1) reduce noise and 2) produce a compact textural description. The wedgelet enhanced appearance model...

  6. Ecologically Enhancing Coastal Infrastructure

    Science.gov (United States)

    Mac Arthur, Mairi; Naylor, Larissa; Hansom, Jim; Burrows, Mike; Boyd, Ian

    2017-04-01

    Hard engineering structures continue to proliferate in the coastal zone globally in response to increasing pressures associated with rising sea levels, coastal flooding and erosion. These structures are typically plain-cast by design and function as poor ecological surrogates for natural rocky shores which are highly topographically complex and host a range of available microhabitats for intertidal species. Ecological enhancement mitigates some of these negative impacts by integrating components of nature into the construction and design of these structures to improve their sustainability, resilience and multifunctionality. In the largest UK ecological enhancement trial to date, 184 tiles (15x15cm) of up to nine potential designs were deployed on vertical concrete coastal infrastructure in 2016 at three sites across the UK (Saltcoats, Blackness and Isle of Wight). The surface texture and complexity of the tiles were varied to test the effect of settlement surface texture at the mm-cm scale of enhancement on the success of colonisation and biodiversity in the mid-upper intertidal zone in order to answer the following experimental hypotheses: • Tiles with mm-scale geomorphic complexity will have greater barnacle abundances • Tiles with cm-scale geomorphic complexity will have greater species richness than mm-scale tiles. A range of methods were used in creating the tile designs including terrestrial laser scanning of creviced rock surfaces to mimic natural rocky shore complexity as well as artificially generated complexity using computer software. The designs replicated the topographic features of high ecological importance found on natural rocky shores and promoted species recruitment and community composition on artificial surfaces; thus enabling us to evaluate biological responses to geomorphic complexity in a controlled field trial. At two of the sites, the roughest tile designs (cm scale) did not have the highest levels of barnacle recruits which were

  7. Color image and video enhancement

    CERN Document Server

    Lecca, Michela; Smolka, Bogdan

    2015-01-01

    This text covers state-of-the-art color image and video enhancement techniques. The book examines the multivariate nature of color image/video data as it pertains to contrast enhancement, color correction (equalization, harmonization, normalization, balancing, constancy, etc.), noise removal and smoothing. This book also discusses color and contrast enhancement in vision sensors and applications of image and video enhancement.   ·         Focuses on enhancement of color images/video ·         Addresses algorithms for enhancing color images and video ·         Presents coverage on super resolution, restoration, in painting, and colorization.

  8. The Enhanced Speed Bag System

    Science.gov (United States)

    2016-03-18

    July–August 2015 Army Sustainment46 The enhanced speed bag sys-tem (ESBS) is a cutting-edge piece of equipment. Its pur- pose is to facilitate...reasonable speed (20 knots). The ESBS enables Sol- diers to conduct quick and accurate resupply operations while avoiding enemy small-arms fire and...Afghanistan, from December 2014 to January 2015. ESBS Specifications The ESBS is composed of the The Enhanced Speed Bag System The enhanced speed bag

  9. Optical Enhancement of Degraded Fingerprints.

    Science.gov (United States)

    1986-05-01

    They form a general set of simple filters that can enhance various types of degraded fingerprints ( whorl , central pocket loop, tented arch, twinned...section 1). Both the degraded fingerprint and its enhancement are shown and discussed. The first degraded fingerprint , shown in Figure 4-6(a), is a whorl ...Enhancement of Degraded Fingerprints THESIS/WWATIO 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(s) 8. CONTRACT OR GRANT NUMBER(s) Hal Erling Olimb

  10. Enhanced Micellar Catalysis LDRD.

    Energy Technology Data Exchange (ETDEWEB)

    Betty, Rita G.; Tucker, Mark D; Taggart, Gretchen; Kinnan, Mark K.; Glen, Crystal Chanea; Rivera, Danielle; Sanchez, Andres; Alam, Todd Michael

    2012-12-01

    The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesotas Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters.

  11. Enhanced sampling algorithms.

    Science.gov (United States)

    Mitsutake, Ayori; Mori, Yoshiharu; Okamoto, Yuko

    2013-01-01

    In biomolecular systems (especially all-atom models) with many degrees of freedom such as proteins and nucleic acids, there exist an astronomically large number of local-minimum-energy states. Conventional simulations in the canonical ensemble are of little use, because they tend to get trapped in states of these energy local minima. Enhanced conformational sampling techniques are thus in great demand. A simulation in generalized ensemble performs a random walk in potential energy space and can overcome this difficulty. From only one simulation run, one can obtain canonical-ensemble averages of physical quantities as functions of temperature by the single-histogram and/or multiple-histogram reweighting techniques. In this article we review uses of the generalized-ensemble algorithms in biomolecular systems. Three well-known methods, namely, multicanonical algorithm, simulated tempering, and replica-exchange method, are described first. Both Monte Carlo and molecular dynamics versions of the algorithms are given. We then present various extensions of these three generalized-ensemble algorithms. The effectiveness of the methods is tested with short peptide and protein systems.

  12. Allergens: An Enhanced Focus.

    Science.gov (United States)

    Spotz, Kristen

    2018-01-01

    Food Allergy Awareness Week was created with the purpose of placing a spotlight on the seriousness of food allergies. Recognized in the United States in mid-May every year, Food Allergy Awareness Week serves as a reminder of the over 15 million Americans who suffer from food allergies. The importance of allergies and allergen labeling can be seen when looking at U.S. Food and Drug Administration recall data: of the 764 recalls in 2016, 305 (representing more than 40%) were due to undeclared allergens. However, recalls for undeclared allergens are a complex issue with numerous factors. The implementation of prevention-based systems with the necessary management components and further error-proofing the systems, along with allergen awareness embedded throughout a company's food safety culture, can likely help reduce the number of recalls for undeclared allergens. As a resource to manufacturers, the Grocery Manufacturers Association and the Food Allergy Research and Resource Program have developed several resources to assist with developing robust allergen management programs. By reducing the number of recalls for undeclared allergens, the food industry will likely increase and maintain consumer confidence and trust of the food-allergic community. This enhanced consumer confidence and trust could eventually open the door for further collaboration with the food-allergic community and, potentially, advance allergen-related policies.

  13. Development of enhanced radioprotectors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Chun, K. J.; Lee, Y. K.; Kim, Y. K.; Lee, B. H.; Song, H. S.; Lee, C. J.; Chung, K. M.; Shin, H. S.; Park, T. W

    2000-04-01

    Biological model systems such as TSH mutations, animals and their reproductive organs, and cultured cell lines and human peripheral lymphocytes have been set up for screening radioprotective or radiosensitizing activities of natural products. About 100 natural plants were in vivo and in vitro tested. Among them, Salvia miltiorrhiza, Areca catechu, Cornus officinalis, and portulaca oleracea showed 20 percent of radioprotective activities. On the other hand, Acanthopanax sessiliflous, Melia japonica, and Agastache rugosa revealed radiosensitizing activities. Experimental studies on the farnesyl transferase inhibitors showed the results that some of the inhibitors lead to higher levels of cell death after {gamma}-irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. Molecular biochemical studies on the mechanism of radioprotection was carried out using cultured cells. The treatment of DTT increased cell survival after gamma-irradiation,decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. The result of mechanism studies will be applied to elucidate the radioprotection mechanism and to develop enhanced radioprotectors. Furthermore, our results indicate that use of antioxidants in combination can efficiently modulate the radiation-induced cell damage like apoptosis and can be applied to alleviate the cellular damage in tumor patients during radiotherapy. (author)

  14. Enhancing chemical reactions

    Science.gov (United States)

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  15. Development of enhanced radioprotectors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Park, K.B.; Lee, Y.I. [and others

    1999-04-01

    Biological model systems such as TSH mutations, animals and their reproductive organs, and cultured cell lines has been set up for screening radioprotective or radiosensitizing activities of natural products. About 100 natural plants were in vivo and in vitro tested. Among them, Salvia miltiorrhiza, Areca catechu, Cornus officinalis, and Portulaca oleracea showed 20% of radioprotective activities. On the other hand, Acanthopanax sessiliflous, Melia japonica, and Agastache rugosa revealed radiosensitizing activities. Experimental studies on the farnesyltransferase inhibitors showed the results that some of the inhibits lead to higher levels of cell death after {gamma} -irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. Molecular biochemical studies on the mechanism of radioprotection was carried out using cultured cells. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. Samples shown excellent radioprotective or radiosensitizing activities will be subjected to purification to develop radioprotectants and radiosensitizers applicable to human beings. The result of mechanism studies will be applied to elucidate the radioprotection mechanism and the develop enhanced radioprotectors. (author). 145 refs., 21 tabs., 29 figs.

  16. Development of enhanced radioprotectors

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Park, K.B.; Lee, Y.I.

    1999-04-01

    Biological model systems such as TSH mutations, animals and their reproductive organs, and cultured cell lines has been set up for screening radioprotective or radiosensitizing activities of natural products. About 100 natural plants were in vivo and in vitro tested. Among them, Salvia miltiorrhiza, Areca catechu, Cornus officinalis, and Portulaca oleracea showed 20% of radioprotective activities. On the other hand, Acanthopanax sessiliflous, Melia japonica, and Agastache rugosa revealed radiosensitizing activities. Experimental studies on the farnesyltransferase inhibitors showed the results that some of the inhibits lead to higher levels of cell death after γ -irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. Molecular biochemical studies on the mechanism of radioprotection was carried out using cultured cells. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. Samples shown excellent radioprotective or radiosensitizing activities will be subjected to purification to develop radioprotectants and radiosensitizers applicable to human beings. The result of mechanism studies will be applied to elucidate the radioprotection mechanism and the develop enhanced radioprotectors. (author). 145 refs., 21 tabs., 29 figs

  17. Development of enhanced radioprotectors

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Chun, K. J.; Lee, Y. K.; Kim, Y. K.; Lee, B. H.; Song, H. S.; Lee, C. J.; Chung, K. M.; Shin, H. S.; Park, T. W.

    2000-04-01

    Biological model systems such as TSH mutations, animals and their reproductive organs, and cultured cell lines and human peripheral lymphocytes have been set up for screening radioprotective or radiosensitizing activities of natural products. About 100 natural plants were in vivo and in vitro tested. Among them, Salvia miltiorrhiza, Areca catechu, Cornus officinalis, and portulaca oleracea showed 20 percent of radioprotective activities. On the other hand, Acanthopanax sessiliflous, Melia japonica, and Agastache rugosa revealed radiosensitizing activities. Experimental studies on the farnesyl transferase inhibitors showed the results that some of the inhibitors lead to higher levels of cell death after γ-irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. Molecular biochemical studies on the mechanism of radioprotection was carried out using cultured cells. The treatment of DTT increased cell survival after gamma-irradiation,decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. The result of mechanism studies will be applied to elucidate the radioprotection mechanism and to develop enhanced radioprotectors. Furthermore, our results indicate that use of antioxidants in combination can efficiently modulate the radiation-induced cell damage like apoptosis and can be applied to alleviate the cellular damage in tumor patients during radiotherapy. (author)

  18. ENHANCE: Enhancing Brain Plasticity for Sensorimotor Recovery in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ENHANCE: Enhancing Brain Plasticity for Sensorimotor Recovery in Spastic Hemiparesis. Often, people who have had a stroke experience problems recovering the use of their arms, and the issue may persist for a long time. This research will test new ways to boost recovery using non-painful brain stimulation and ...

  19. Plasmon Enhanced Photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Polyakov, Aleksandr [Univ. of California, Berkeley, CA (United States)

    2012-05-08

    this work, the structure consisted of rectangular nano-grooves (NGs) arranged in a subwavelength grating on a metal surface is presented that provides a dramatic increase in the metal’s absorption, field localization, and field enhancement. When light is polarized perpendicular to the orientation of the grooves a standing SPP wave is excited along the vertical walls in the NGs, that act as Fabry-Perot resonators. By adjusting the geometry of the NGs and the period of the subwavelength grating the resonance can be fine tuned to a desired position, for example, the laser fundamental wavelength, anywhere from the UV to the near infrared (NIR). Two types of gratings are presented: (a) a gold grating with period of 600 nm, and (b) an aluminum-gold grating with a period of 100 nm; both with resonance at 720 nm. In each case, strong on-resonance absorption was observed, with over 98% for grating (b). Unlike the grating-coupled SPP waves, where the angle is well defined by the momentum matching condition, the resonant NGs allow coupling to the standing modes at a range of angles of incidence, referred to as the angular bandwidth. A new model for the on-resonance absorption based on the ensamble action of the NGs is presented that serves as the basis for a design of an NG grating with an ultrawide spectral as well as angular bandwidth. For sample (b), the angular bandwidth is 80 degrees, corresponding to an opening angle of 160 degrees. The photoemission enhancement for such a grating was measured to be seven orders of magnitude for a four-photon photoemission. This is an incredible result demonstrating the power of the plasmonic grating presented, which is an efficient light trapper and field enhancer for a non-linear processes. These results demonstrate that the metal photocathode prepared with a NG grating on the metal surface will provide sufficient pulse charge driven by a 1 μJ 15fs pulsed laser at 800 nm for the optimum FEL operation.

  20. PENGARUH KONSENTRASI GIBERELIN TERHADAP PRODUKSI BIBIT KENTANG (SOLANUM TUBEROSUM L. CV. GRANOLA UKURAN M (31 - 60 GRAM

    Directory of Open Access Journals (Sweden)

    Ni Luh Arpiwi

    2007-06-01

    Full Text Available The aim of the research was to increase the production of seed potato size 31 - 60 grams by applying gibberellic acid (GA3. Seeds that passed their dormancy period were dipped in gibberellic acid solutions (10, 15 and 20 mg/L for 15 minutes a day before planting. Control seeds were dipped in water. Seeds were then air dried for 24 hours. Seeds were planted in plots with length, width and height of 150 x 100 x 30 cm respectively with planting space 20 cm and planting depth 15 cm. The design was randomized block with four replications. The results showed that gibberellic acid enhanced shoot emergence. Gibberellic acid increased stem number, tuber number and yield per plant. Tuber number and yield of size M (31 ? 60 g increased, whereas tuber number and yield of size LL decreased drastically. The optimum concentration of gibberellin for these increases was 15 mg/L. Plant height was not influenced by gibberellic acid.

  1. Motif signatures of transcribed enhancers

    KAUST Repository

    Kleftogiannis, Dimitrios

    2017-09-14

    In mammalian cells, transcribed enhancers (TrEn) play important roles in the initiation of gene expression and maintenance of gene expression levels in spatiotemporal manner. One of the most challenging questions in biology today is how the genomic characteristics of enhancers relate to enhancer activities. This is particularly critical, as several recent studies have linked enhancer sequence motifs to specific functional roles. To date, only a limited number of enhancer sequence characteristics have been investigated, leaving space for exploring the enhancers genomic code in a more systematic way. To address this problem, we developed a novel computational method, TELS, aimed at identifying predictive cell type/tissue specific motif signatures. We used TELS to compile a comprehensive catalog of motif signatures for all known TrEn identified by the FANTOM5 consortium across 112 human primary cells and tissues. Our results confirm that distinct cell type/tissue specific motif signatures characterize TrEn. These signatures allow discriminating successfully a) TrEn from random controls, proxy of non-enhancer activity, and b) cell type/tissue specific TrEn from enhancers expressed and transcribed in different cell types/tissues. TELS codes and datasets are publicly available at http://www.cbrc.kaust.edu.sa/TELS.

  2. Metaheuristic applications to speech enhancement

    CERN Document Server

    Kunche, Prajna

    2016-01-01

    This book serves as a basic reference for those interested in the application of metaheuristics to speech enhancement. The major goal of the book is to explain the basic concepts of optimization methods and their use in heuristic optimization in speech enhancement to scientists, practicing engineers, and academic researchers in speech processing. The authors discuss why it has been a challenging problem for researchers to develop new enhancement algorithms that aid in the quality and intelligibility of degraded speech. They present powerful optimization methods to speech enhancement that can help to solve the noise reduction problems. Readers will be able to understand the fundamentals of speech processing as well as the optimization techniques, how the speech enhancement algorithms are implemented by utilizing optimization methods, and will be given the tools to develop new algorithms. The authors also provide a comprehensive literature survey regarding the topic.

  3. Resolution Enhancement of Multilook Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Galbraith, Amy E. [Univ. of Arizona, Tucson, AZ (United States)

    2004-07-01

    This dissertation studies the feasibility of enhancing the spatial resolution of multi-look remotely-sensed imagery using an iterative resolution enhancement algorithm known as Projection Onto Convex Sets (POCS). A multi-angle satellite image modeling tool is implemented, and simulated multi-look imagery is formed to test the resolution enhancement algorithm. Experiments are done to determine the optimal con guration and number of multi-angle low-resolution images needed for a quantitative improvement in the spatial resolution of the high-resolution estimate. The important topic of aliasing is examined in the context of the POCS resolution enhancement algorithm performance. In addition, the extension of the method to multispectral sensor images is discussed and an example is shown using multispectral confocal fluorescence imaging microscope data. Finally, the remote sensing issues of atmospheric path radiance and directional reflectance variations are explored to determine their effect on the resolution enhancement performance.

  4. COMPARISON OF IMAGE ENHANCEMENT METHODS FOR CHROMOSOME KARYOTYPE IMAGE ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    Dewa Made Sri Arsa

    2017-02-01

    Full Text Available The chromosome is a set of DNA structure that carry information about our life. The information can be obtained through Karyotyping. The process requires a clear image so the chromosome can be evaluate well. Preprocessing have to be done on chromosome images that is image enhancement. The process starts with image background removing. The image will be cleaned background color. The next step is image enhancement. This paper compares several methods for image enhancement. We evaluate some method in image enhancement like Histogram Equalization (HE, Contrast-limiting Adaptive Histogram Equalization (CLAHE, Histogram Equalization with 3D Block Matching (HE+BM3D, and basic image enhancement, unsharp masking. We examine and discuss the best method for enhancing chromosome image. Therefore, to evaluate the methods, the original image was manipulated by the addition of some noise and blur. Peak Signal-to-noise Ratio (PSNR and Structural Similarity Index (SSIM are used to examine method performance. The output of enhancement method will be compared with result of Professional software for karyotyping analysis named Ikaros MetasystemT M . Based on experimental results, HE+BM3D method gets a stable result on both scenario noised and blur image.

  5. Enhanced Design Alternative IV

    International Nuclear Information System (INIS)

    Kramer, N.E.

    1999-01-01

    This report evaluates Enhanced Design Alternative (EDA) IV as part of the second phase of the License Application Design Selection (LADS) effort. The EDA IV concept was compared to the VA reference design using criteria from the Design Input Request for LADS Phase II EDA Evaluations (CRWMS M and O 1999b) and (CRWMS M and O 1999f). Briefly, the EDA IV concept arranges the waste packages close together in an emplacement configuration known as line load. Continuous pre-closure ventilation keeps the waste packages from exceeding their 350 C cladding and 200 C (4.3.6) drift wall temperature limits. This EDA concept keeps relatively high, uniform emplacement drift temperatures (post-closure) to drive water away from the repository and thus dry out the pillars between emplacement drifts. The waste package is shielded to permit human access to emplacement drifts and includes an integral filler inside the package to reduce the amount of water that can contact the waste form. Closure of the repository is desired 50 years after first waste is emplaced. Both backfill and drip shields will be emplaced at closure to improve post-closure performance. The EDA IV concept includes more defense-in-depth layers than the VA reference design because of its backfill, drip shield, waste package shielding, and integral filler features. These features contribute to the low dose-rate to the public achieved during the first 10,000 years of repository life as shown in Figure 3. Investigation of the EDA IV concept has led to the following general conclusions: (1) The total life cycle cost for EDA IV is about $21.7 billion which equates to a $11.3 billion net present value (both figures rounded up). (2) The incidence of design basis events for EDA IV is similar to the VA reference design. (3) The emplacement of the waste packages in drifts will be similar to the VA reference design. However, heavier equipment may be required because the shielded waste package will be heavier. (4) The heavier

  6. Environmental engineering education enhancement

    Science.gov (United States)

    Caporali, E.

    2012-04-01

    Since higher education plays a central role in the development of both human beings and modern societies, enhancing social, cultural and economic development, active citizenship, ethical values and expertises for a sustainable growth, environment respectful, the European Commission promotes a wide range of programmes. Among the EC programmes, the TEMPUS - Trans European Mobility Programme for University Studies, with the support of the DG EAC of the European Commission, has contributed to many aspects of general interest for higher education. Curricula harmonization, LifeLong Learning Programme development, ICT use, quality assessment, accreditation, innovation learning methods, growth of networks of institutions trusting each other, are the focused aspects. Such a solid cooperation framework is surely among the main outcomes of the TEMPUS Projects leaded by the University of Firenze UNIFI (Italy), DEREC - Development of Environment and Resources Engineering Curriculum (2005-2008), and its spin-off DEREL - Development of Environment and Resources Engineering Learning (2010-2013), and VICES - Videoconferencing Educational Services (2009-2012). DEREC and DEREL TEMPUS projects, through the co-operation of Universities in Italy, Austria, Germany, Greece, Macedonia, Albania and Serbia, are aimed at the development of first and second level curricula in "Environment and Resources Engineering" at the Ss. Cyril and Methodius University - UKIM Skopje (MK). In the DEREC Project the conditions for offering a joint degree title in the field of Environmental Engineering between UNIFI and UKIM Skopje were fulfilled and a shared educational programme leading to the mutual recognition of degree titles was defined. The DEREL project, as logical continuation of DEREC, is aimed to introduce a new, up-to-date, postgraduate second level curriculum in Environment and Resources Engineering at UKIM Skopje, University of Novi Sad (RS) and Polytechnic University of Tirana (AL). following

  7. Excitation enhancement and extraction enhancement with photonic crystals

    Science.gov (United States)

    Shapira, Ofer; Soljacic, Marin; Zhen, Bo; Chua, Song-Liang; Lee, Jeongwon; Joannopoulos, John

    2015-03-03

    Disclosed herein is a system for stimulating emission from at least one an emitter, such as a quantum dot or organic molecule, on the surface of a photonic crystal comprising a patterned dielectric substrate. Embodiments of this system include a laser or other source that illuminates the emitter and the photonic crystal, which is characterized by an energy band structure exhibiting a Fano resonance, from a first angle so as to stimulate the emission from the emitter at a second angle. The coupling between the photonic crystal and the emitter may result in spectral and angular enhancement of the emission through excitation and extraction enhancement. These enhancement mechanisms also reduce the emitter's lasing threshold. For instance, these enhancement mechanisms enable lasing of a 100 nm thick layer of diluted organic molecules solution with reduced threshold intensity. This reduction in lasing threshold enables more efficient organic light emitting devices and more sensitive molecular sensing.

  8. Resolution enhancement techniques in microscopy

    Science.gov (United States)

    Cremer, Christoph; Masters, Barry R.

    2013-05-01

    We survey the history of resolution enhancement techniques in microscopy and their impact on current research in biomedicine. Often these techniques are labeled superresolution, or enhanced resolution microscopy, or light-optical nanoscopy. First, we introduce the development of diffraction theory in its relation to enhanced resolution; then we explore the foundations of resolution as expounded by the astronomers and the physicists and describe the conditions for which they apply. Then we elucidate Ernst Abbe's theory of optical formation in the microscope, and its experimental verification and dissemination to the world wide microscope communities. Second, we describe and compare the early techniques that can enhance the resolution of the microscope. Third, we present the historical development of various techniques that substantially enhance the optical resolution of the light microscope. These enhanced resolution techniques in their modern form constitute an active area of research with seminal applications in biology and medicine. Our historical survey of the field of resolution enhancement uncovers many examples of reinvention, rediscovery, and independent invention and development of similar proposals, concepts, techniques, and instruments. Attribution of credit is therefore confounded by the fact that for understandable reasons authors stress the achievements from their own research groups and sometimes obfuscate their contributions and the prior art of others. In some cases, attribution of credit is also made more complex by the fact that long term developments are difficult to allocate to a specific individual because of the many mutual connections often existing between sometimes fiercely competing, sometimes strongly collaborating groups. Since applications in biology and medicine have been a major driving force in the development of resolution enhancing approaches, we focus on the contribution of enhanced resolution to these fields.

  9. Speech enhancement theory and practice

    CERN Document Server

    Loizou, Philipos C

    2013-01-01

    With the proliferation of mobile devices and hearing devices, including hearing aids and cochlear implants, there is a growing and pressing need to design algorithms that can improve speech intelligibility without sacrificing quality. Responding to this need, Speech Enhancement: Theory and Practice, Second Edition introduces readers to the basic problems of speech enhancement and the various algorithms proposed to solve these problems. Updated and expanded, this second edition of the bestselling textbook broadens its scope to include evaluation measures and enhancement algorithms aimed at impr

  10. Geothermal Permeability Enhancement - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  11. Surface-Enhanced Raman Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 2. Surface-Enhanced Raman Spectroscopy - Recent Advancement of Raman Spectroscopy. Ujjal Kumar Sur. General Article Volume 15 Issue 2 February 2010 pp 154-164 ...

  12. NCPA Enhancement for Physical Acoustics

    National Research Council Canada - National Science Library

    Bass, Henry

    2001-01-01

    ...-rate scientists and students and carry out effective, ONR-supported research. Specific objectives of this grant are to support research and recruitment by enhancing the infrastructure in physical acoustics...

  13. Enhanced Master Station History Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Master Station History Report (EMSHR) is a compiled list of basic, historical information for every station in the station history database, beginning...

  14. Modelling of reverberation enhancement systems

    OpenAIRE

    ROUCH , Jeremy; Schmich , Isabelle; Galland , Marie-Annick

    2012-01-01

    International audience; Electroacoustic enhancement systems are increasingly specified by acoustic consultants to address the requests for a multi-purpose use of performance halls. However, there is still a lack of simple models to predict the effect induced by these systems on the acoustic field. Two models are introduced to establish the impulse responses of a room equipped with a reverberation enhancement system. These models are based on passive impulse responses according to the modified...

  15. Psychopharmacological enhancement: a conceptual framework

    OpenAIRE

    Stein, Dan J

    2012-01-01

    Abstract The availability of a range of new psychotropic agents raises the possibility that these will be used for enhancement purposes (smart pills, happy pills, and pep pills). The enhancement debate soon raises questions in philosophy of medicine and psychiatry (eg, what is a disorder?), and this debate in turn raises fundament questions in philosophy of language, science, and ethics. In this paper, a naturalistic conceptual framework is proposed for addressing these issues. This framework...

  16. Multiscale based adaptive contrast enhancement

    Science.gov (United States)

    Abir, Muhammad; Islam, Fahima; Wachs, Daniel; Lee, Hyoung

    2013-02-01

    A contrast enhancement algorithm is developed for enhancing the contrast of x-ray images. The algorithm is based on Laplacian pyramid image processing technique. The image is decomposed into three frequency sub-bands- low, medium, and high. Each sub-band contains different frequency information of the image. The detail structure of the image lies on the high frequency sub-band and the overall structure lies on the low frequency sub-band. Apparently it is difficult to extract detail structure from the high frequency sub-bands. Enhancement of the detail structures is necessary in order to find out the calcifications on the mammograms, cracks on any object such as fuel plate, etc. In our proposed method contrast enhancement is achieved from high and medium frequency sub-band images by decomposing the image based on multi-scale Laplacian pyramid and enhancing contrast by suitable image processing. Standard Deviation-based Modified Adaptive contrast enhancement (SDMACE) technique is applied to enhance the low-contrast information on the sub-bands without overshooting noise. An alpha-trimmed mean filter is used in SDMACE for sharpness enhancement. After modifying all sub-band images, the final image is derived from reconstruction of the sub-band images from lower resolution level to upper resolution level including the residual image. To demonstrate the effectiveness of the algorithm an x-ray of a fuel plate and two mammograms are analyzed. Subjective evaluation is performed to evaluate the effectiveness of the algorithm. The proposed algorithm is compared with the well-known contrast limited adaptive histogram equalization (CLAHE) algorithm. Experimental results prove that the proposed algorithm offers improved contrast of the x-ray images.

  17. Field enhancement induced laser ablation

    DEFF Research Database (Denmark)

    Fiutowski, Jacek; Maibohm, Christian; Kjelstrup-Hansen, Jakob

    Sub-diffraction spatially resolved, quantitative mapping of strongly localized field intensity enhancement on gold nanostructures via laser ablation of polymer thin films is reported. Illumination using a femtosecond laser scanning microscope excites surface plasmons in the nanostructures....... The accompanying field enhancement substantially lowers the ablation threshold of the polymer film and thus creates local ablation spots and corresponding topographic modifications of the polymer film. Such modifications are quantified straightforwardly via scanning electron and atomic force microscopy. Thickness...

  18. Bose enhancement and the ridge

    Directory of Open Access Journals (Sweden)

    Tolga Altinoluk

    2015-12-01

    Full Text Available We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  19. Bose enhancement and the ridge

    Energy Technology Data Exchange (ETDEWEB)

    Altinoluk, Tolga [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Armesto, Néstor, E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Beuf, Guillaume [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Kovner, Alex [Physics Department, University of Connecticut, 2152 Hillside Road, Storrs, CT 06269-3046 (United States); Lublinsky, Michael [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel)

    2015-12-17

    We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  20. Pharmacological cognitive enhancement in pediatrics.

    Science.gov (United States)

    Colaneri, Natalie; Sheldon, Mark; Adesman, Andrew

    2018-03-13

    Given the pervasiveness of psychotropic medication in the youth population and an increasingly competitive culture regarding educational performance, children, teenagers, and/or their parents may increasingly seek psychotropic substances in an effort to enhance a student's cognitive abilities and/or academic performance. Physicians must become aware of this very important and clinically relevant issue and work to ensure that medications remain in the hands of patients seeking wellness and not enhancement. The current article highlights findings on the pervasiveness of stimulant misuse and diversion in youth, the motivations and effects of stimulant use, health and legal consequences associated with use, and physician perceptions and preventive practices. Ethical concerns regarding pharmacological cognitive enhancement in pediatrics are also outlined - including coercion for nonusers, inequities in access, and threats to an individual's sense of self with regard to authenticity and autonomy. Pharmacological cognitive enhancement in pediatrics will become a larger, clinically relevant issue in the coming years. Physicians who care for children and adolescents must become more aware of this issue. Given the myriad health, legal, and ethical concerns, clinicians should discourage use of pharmaceuticals for enhancement purposes in the pediatric population.

  1. Enhanced sludge washing evaluation plan

    International Nuclear Information System (INIS)

    Jensen, R.D.

    1994-09-01

    The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices

  2. Retinex enhancement of infrared images.

    Science.gov (United States)

    Li, Ying; He, Renjie; Xu, Guizhi; Hou, Changzhi; Sun, Yunyan; Guo, Lei; Rao, Liyun; Yan, Weili

    2008-01-01

    With the ability of imaging the temperature distribution of body, infrared imaging is promising in diagnostication and prognostication of diseases. However the poor quality of the raw original infrared images prevented applications and one of the essential problems is the low contrast appearance of the imagined object. In this paper, the image enhancement technique based on the Retinex theory is studied, which is a process that automatically retrieve the visual realism to images. The algorithms, including Frackle-McCann algorithm, McCann99 algorithm, single-scale Retinex algorithm, multi-scale Retinex algorithm and multi-scale Retinex algorithm with color restoration, are experienced to the enhancement of infrared images. The entropy measurements along with the visual inspection were compared and results shown the algorithms based on Retinex theory have the ability in enhancing the infrared image. Out of the algorithms compared, MSRCR demonstrated the best performance.

  3. Contrast enhancement CT by iopamidol

    International Nuclear Information System (INIS)

    Mori, Masaki; Makita, Nobue; Yanai, Kyoko

    1984-01-01

    In order to evaluate the contrast enhancement effect and safety of iopamidol (IOP) in CT examination, IOP was compared with angiographin (AG). In the liver and abdominal aorta, peak CT values were obtained earlier and were higher in the group with AG than in the group with IOP. However, CT values in the group with IOP decreased a little more slowly than those in the group with AG. There was no significant difference in the effect on contrast enhancement between the groups. Intravenous injection of IOP caused lower degree of burning sensation than that of AG, and some of the patients with IOP did not feel burning sensation at all. Changes in clinical laboratory values were slight before and after intravenous injection of IOP. These results suggest that IOP is satisfactory in terms of safety and effect on contrast enhancement in CT examination. (Namekawa, K.)

  4. Safety enhancement in NPP Bohunice

    International Nuclear Information System (INIS)

    Lipar, M.; Mihalik, M.

    1997-01-01

    The upgrading and safety enhancement of both the Bohunice V-1 and V-2 reactors is described in detail. The total estimated cost of the gradual reconstruction of these two units during 1996 to 1999 is 180 mil. US dollars. For the 1995 to 1997 period, the actions common for both units include a quality assurance programme, a personnel training programme, installation of a multifunction simulator, implementation of symptom-oriented operation procedures, installation of diagnostic systems, of a site security system, and of a teledosimetric system. At present, the main maintenance tasks are: to carry out major repair of units, to remedy service interruptions, to enhance equipment service availability, to enhance the technical level of corrective actions at equipment. Investment into maintenance level upgrade has grown from 7.5 mil. Slovak crowns in 1994 to estimated 32 mil. in 2000. The partners of international cooperation are mentioned. (M.D.)

  5. Enhancing graduate employability for enhancing the role of higher ...

    African Journals Online (AJOL)

    ... to enhance graduate employability through curricular, co-curricular and extracurricular activities are concerned, much has not been done in all cases. In nutshell, the agenda of graduate employability has not been given adequate attention at all levels: policy, strategy, curriculum & instruction, research and development.

  6. Convection-enhanced water evaporation

    Directory of Open Access Journals (Sweden)

    B. M. Weon

    2011-03-01

    Full Text Available Water vapor is lighter than air; this can enhance water evaporation by triggering vapor convection but there is little evidence. We directly visualize evaporation of nanoliter (2 to 700 nL water droplets resting on silicon wafer in calm air using a high-resolution dual X-ray imaging method. Temporal evolutions of contact radius and contact angle reveal that evaporation rate linearly changes with surface area, indicating convective (instead of diffusive evaporation in nanoliter water droplets. This suggests that convection of water vapor would enhance water evaporation at nanoliter scales, for instance, on microdroplets or inside nanochannels.

  7. Nanoparticles for cells proliferation enhancement

    International Nuclear Information System (INIS)

    Popa, V.; Braniste, F.; Tiginyanu, I.M.; Lisii, C.; Nacu, V.

    2013-01-01

    The potential of semiconductor nanoparticles as stimulator for avian mesenchyme stem cells proliferation enhancement is demonstrated. The effect is related to nanoparticles polarization due to external ultrasound field resulting in local electrical stimulation. Our preliminary results demonstrates that the number of cells have been increased by 23 % ±2%) in cell cultures under the action of external ultrasound stimulation. Morphological analysis and viability shows no differences between the control group and the group studied. These results suggest the possibility for tissue regeneration enhancement by remote stimulation of implanted semiconductor nanoparticles. (authors)

  8. Dynamic water vapor sorption on Mg(Ga3+)O mixed oxides: Analysis of the LDH thermal regeneration process

    International Nuclear Information System (INIS)

    Bedolla-Valdez, Zaira I.; Ramirez-Solis, Sergio; Prince, Julia; Lima, Enrique; Pfeiffer, Heriberto; Valente, Jaime S.

    2013-01-01

    Highlights: ► Ga-LDH regeneration process was analyzed varying the relative humidity. ► Ga-LDH rehydrates faster than aluminum content LDH materials. ► Gallium seems to favor diffusion processeses during LDH regeneration. - Abstract: The rehydration process of the calcined MgGa-layered double hydroxides (Ga-LDH) was analyzed at different temperatures and relative humidities. Results clearly showed that Ga-LDH sample presented an excellent regeneration kinetic, in comparison to the aluminum typical one. Different techniques such as X-ray diffraction, infrared spectroscopy and thermal analysis were used to elucidate the presented results

  9. Complexes of gastrin with In3+, Ru3+ or Ga3+ ions are not recognised by the cholecystokinin 2 receptor.

    Science.gov (United States)

    Laval, Marie; Marshall, Kathryn M; Sachinidis, John; Scott, Andrew; Eutick, Mal; Baldwin, Graham S

    2017-10-01

    The peptide hormone gastrin (Gamide) binds trivalent metal ions, including indium (In), ruthenium (Ru) and gallium (Ga), with high affinity. Complexes of gastrin with chelated isotopes of In and Ga have previously been used for the location of tumours expressing the cholecystokinin 2 receptor (CCK2R). The aim of the present study was to purify the complexes of Gamide with radioactive isotopes of In, Ru or Ga and to investigate their ability to bind to the CCK2R. The radioactive Gamide complexes were purified on Sep-Pak C18 cartridges or by anion exchange HPLC. Binding to the CCK2R was assessed with a stably transfected clone of the gastric carcinoma cell line AGS. The 106 Ru-Gamide complex could be eluted from the C18 cartridge; the 111 In-Gamide and 68 Ga-Gamide complexes bound irreversibly. All three complexes were successfully purified by anion exchange HPLC. The failure to detect binding of the 111 In-Gamide, 106 Ru-Gamide and 68 Ga-Gamide complexes to the CCK2R suggests that formation of these complexes will not be useful for the detection of tumours expressing this receptor, but may instead provide alternative ways to block the actions of Gamide as a growth factor or a stimulant of gastric acid secretion. The complexes between the hormone gastrin and radioactive 111 In, 106 Ru or 68 Ga ions were purified by anion exchange HPLC using a NaCl gradient. The failure to detect binding of the complexes to the cholecystokinin 2 receptor suggests that metal ion treatment may provide novel approaches to block the biological actions of gastrin.

  10. Enhancements to PVM's BEOLIN architecture

    Science.gov (United States)

    Springer, Paul L.

    2005-01-01

    .4.3 of PVM had previously been enhanced by the addition of a new architecture, BEOLIN, which allowed a PVM user to abstract a Beowulf class computer with a private network to appear as a single system, visible to the outside world, which could spawn tasks on different internal nodes.

  11. Surface-Enhanced Raman Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    In Raman spectroscopy, inelastic scattering of photons from an atom or molecule in chemical entities is utilized to analyze the composition of solids, liquids and gases. However, the low cross-section limits its applications. The introduction of sur- face-enhanced Raman spectroscopy in 1974 has attracted a lot of attention ...

  12. Proceedings Technology Enhanced Assessment conference

    NARCIS (Netherlands)

    Joosten-ten Brinke, Desirée; Laanpere, Mart

    2018-01-01

    This book constitutes the proceedings of the 19th International Conference on Technology Enhanced Assessment, TEA 2016, held in Tallinn, Estonia, in October 2016. The 16 full papers presented were carefully selected from 38 submissions. They are centered around topics like measurement of higher

  13. Who Benefits from Pension Enhancements?

    Science.gov (United States)

    Koedel, Cory; Ni, Shawn; Podgursky, Michael

    2014-01-01

    During the late 1990s public pension funds across the United States accrued large actuarial surpluses. The seemingly flush conditions of the pension funds led legislators in most states to substantially improve retirement benefits for public workers, including teachers. In this study we examine the benefit enhancements to the teacher pension…

  14. Bibliometric-enhanced information retrieval

    NARCIS (Netherlands)

    Mayr, Philipp; Scharnhorst, Andrea; Larsen, Birger; Schaer, Philipp; Mutschke, Peter

    2014-01-01

    Bibliometric techniques are not yet widely used to enhance retrieval processes in digital libraries, although they offer value-added effects for users. In this workshop we will explore how statistical modelling of scholarship, such as Bradfordizing or network analysis of coauthorship network, can

  15. SUPRA - Enhanced upset recovery simulation

    NARCIS (Netherlands)

    Groen, E.; Ledegang, W.; Field, J.; Smaili, H.; Roza, M.; Fucke, L.; Nooij, S.; Goman, M.; Mayrhofer, M.; Zaichik, L.E.; Grigoryev, M.; Biryukov, V.

    2012-01-01

    The SUPRA research project - Simulation of Upset Recovery in Aviation - has been funded by the European Union 7th Framework Program to enhance the flight simulation envelope for upset recovery simulation. Within the project an extended aerodynamic model, capturing the key aerodynamics during and

  16. Bubble chamber: colour enhanced tracks

    CERN Document Server

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  17. Advances in heat transfer enhancement

    CERN Document Server

    Saha, Sujoy Kumar; Sundén, Bengt; Wu, Zan

    2016-01-01

    This Brief addresses the phenomena of heat transfer enhancement. A companion edition in the SpringerBrief Subseries on Thermal Engineering and Applied Science to three other monographs including “Critical Heat Flux in Flow Boiling in Microchannels,” this volume is idea for professionals, researchers, and graduate students concerned with electronic cooling.

  18. Enhancing Author's Voice through Scripting

    Science.gov (United States)

    Young, Chase J.; Rasinski, Timothy V.

    2011-01-01

    The authors suggest using scripting as a strategy to mentor and enhance author's voice in writing. Through gradual release, students use authentic literature as a model for writing with voice. The authors also propose possible extensions for independent practice, integration across content areas, and tips for evaluation.

  19. Enhancing hydrogen spillover and storage

    Science.gov (United States)

    Yang, Ralph T [Ann Arbor, MI; Li, Yingwel [Ann Arbor, MI; Lachawiec, Jr., Anthony J.

    2011-05-31

    Methods for enhancing hydrogen spillover and storage are disclosed. One embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the hydrogen receptor to ultrasonification as doping occurs. Another embodiment of the method includes doping a hydrogen receptor with metal particles, and exposing the doped hydrogen receptor to a plasma treatment.

  20. Enhancing the Productivity of Learning.

    Science.gov (United States)

    Johnstone, D. Bruce

    1995-01-01

    It is argued that colleges and universities can become more productive by enhancing the efficiency of student learning. This requires both acceleration of learning through individually paced mastery learning, better academic focus, year-round schooling, and an earlier start to graduate and professional education. Eight strategies for enhancing…

  1. Engage, Enhance, and Extend Learning!

    Science.gov (United States)

    Keren-Kolb, Liz

    2013-01-01

    Educators often say that technology is more than a gimmick or add-on, and that it should engage, enhance, or extend learning in ways that traditional tools do not. Yet they seldom stop to define these terms, and they can be confusing, especially for teachers and preservice teachers. Recently, while collaborating on an English language arts and…

  2. Enhancing Tumor Penetration of Nanomedicines

    NARCIS (Netherlands)

    Sun, Qingxue; Ojha, Tarun; Kiessling, Fabian; Lammers, Twan; Shi, Yang

    2017-01-01

    Tumor-targeted nanomedicines have been extensively applied to alter the drawbacks and enhance the efficacy of chemotherapeutics. Despite the large number of preclinical nanomedicine studies showing initial success, their therapeutic benefit in the clinic has been rather modest, which is partially

  3. Commercialization of vein contrast enhancement

    Science.gov (United States)

    Lovhoiden, Gunnar; Deshmukh, Harshal; Vrancken, Carlos; Zhang, Yong; Zeman, Herbert D.; Weinberg, Devin

    2003-07-01

    An ongoing clinical study of an experimental infrared (IR) device, the Vein Contrast Enhancer (VCE) that visualizes surface veins for medical access, indicates that a commercial device with the performance of the existing VCE would have significant clinical utility for even a very skilled phlebotomist. A proof-of-principle prototype VCE device has now been designed and constructed that captures IR images of surface veins with a commercial CCD camera, transfers the images to a PC for real-time software image processing to enhance the vein contrast, and projects the enhanced images back onto the skin with a modified commercial LCD projector. The camera and projector are mounted on precision slides allowing for precise mechanical alignment of the two optical axes and for measuring the effects of axes misalignment. Precision alignment of the captured and projected images over the entire field-of-view is accomplished electronically by software adjustments of the translation, scaling, and rotation of the enhanced images before they are projected back onto the skin. This proof-of-principle prototype will be clinically tested and the experience gained will lead to the development of a commercial device, OnTarget!, that is compact, easy to use, and will visualize accessible veins in almost all subjects needing venipuncture.

  4. Cognitive enhancement: a brief overview

    African Journals Online (AJOL)

    healthy people seeking greater productivity. Yet the concept of drug-induced cognitive enhancement is not new. Traditionally, people trying to stay awake and focused in order to manage ... non-licensed purposes to improve academic, work and sporting performance has raised medical, ethical and regulatory issues.

  5. Motivation Enhancement Through Work Redesign.

    Science.gov (United States)

    Oldham, Greg R., Kulik, Carol T.

    1983-01-01

    The possibility of redesigning the work experiences of faculty members in an effort to enhance their motivation, productivity, and personal and work satisfactions is examined. One approach to work redesign, job characteristics theory, is described. Several strategies are discussed. (Author/MLW)

  6. Dimensional enhancement of kinetic energies

    DEFF Research Database (Denmark)

    Schleich, W.P.; Dahl, Jens Peder

    2002-01-01

    Simple thermodynamics considers kinetic energy to be an extensive variable which is proportional to the number N of particles. We present a quantum state of N noninteracting particles for which the kinetic energy increases quadratically with N. This enhancement effect is tied to the quantum...

  7. Innovative Solution to Video Enhancement

    Science.gov (United States)

    2001-01-01

    Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.

  8. Wheat seed enhancement by vitamin and hormonal priming

    International Nuclear Information System (INIS)

    Khan, M.B.; Gurchani, M.A.; Hussain, M.

    2011-01-01

    Seed priming has proven beneficial in many important agricultural crops. The present study was conducted to explore the role (if any) of hormonal and vitamin seed priming to improve the germination, seedling emergence, early seedling establishment, electrolyte leakage and nutrients uptake in wheat seedlings. The wheat seeds were soaked for 48 hours in aerated solution of salicylic acid, ascorbic acid, kinetin and GA3 with 20 ppm concentration of each solution, whereas untreated seeds were taken as control. Seed priming with ascorbic acid resulted in maximum final germination and emergence percentage (FGP and FEP), radical and plumule length, root and shoot length, number of secondary roots, root shoot ratio, root dry weight, shoot dry weight and seedling dry weight compared to control (untreated seeds). Minimum mean germination and emergence time (MGT and MET) was recorded in seeds primed with kinetin and GA3. While in case of biochemical attributes, seedling potassium contents were decreased by hormonal seed priming while total soluble sugars were increased by salicylic acid and ascorbic acid seed priming. Hormonal seed priming had non-significant effect on phosphorus seedling contents. Untreated (Control) seeds showed maximum electrical conductivity at 0.5, 1, 2, 6, 12 and 24 h after inbibition than primed seeds against the minimum electrical conductivity that was recorded in seeds primed with salicylic acid and ascorbic acid. In conclusion, the wheat seeds primed with 20 ppm solution of ascorbic acid may be used for wheat seed invigoration. (author)

  9. Subendometrial enhancement and peritumoral enhancement for assessing endometrial cancer on dynamic contrast enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Shinya [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, Yonago (Japan); Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Kido, Aki, E-mail: akikido@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Baba, Tsukasa [Departments of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Fujimoto, Koji; Daido, Sayaka [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Matsumura, Noriomi; Konishi, Ikuo [Departments of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Togashi, Kaori [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

    2015-04-15

    Highlights: •We have assessed the peritumoral enhancement (PTE), which mimics SEE on DCE. •We evaluated the diagnostic accuracy of SEE for the myometrial invasion and the frequency of PTE. •We assessed the relationship between these enhancements and important pathologic factors. •PTE Type 1 is the main factor causing the overestimation of myometrial invasion using SEE on DCE. •PTE Type 2 correlates the myometrial invasion and may play an important role in the diagnosis of LVSI. -- Abstract: Objectives: To evaluate the diagnostic accuracy of subendometrial enhancement (SEE) in assessing the myometrial invasion in endometrial cancer, the frequency and clinical significance of peritumoral enhancement (PTE) on dynamic contrast enhanced (DCE) imaging. Materials and methods: MR images of 147 patients with endometrial cancer were retrospectively analyzed for intact SEE and PTEs: Type 1, a focal early enhancement peritumorally, and Type 2, an irregular thin-layered early intense enhancement peritumorally. Two radiologists independently assessed intact SEE and PTEs on DCE imaging and compared the lesions by the presence and depth of myometrial invasion, grade, lymphovascular space involvement (LVSI), and lymph node metastasis. The relationship between SEE, PTEs, and each factor was analyzed using univariate and multivariate analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for SEE. Results: The sensitivity, specificity, PPV, NPV and diagnostic accuracy for myometrial invasion based on SEE disruption on DCE were 96.6%, 32.1–46.4%, 85.8–88.5%, 69.2–76.5%, and 84.4–87.1%. According to multivariate analysis, SEE significantly predicted myometrial invasion (p < 0.0001). PTE Type 2 significantly predicted myometrial invasion presence (p < 0.05) and depth (p < 0.01). Conclusion: Diagnosis of myometrial invasion only by using SEE might be difficult on DCE-MRI due to the

  10. Subendometrial enhancement and peritumoral enhancement for assessing endometrial cancer on dynamic contrast enhanced MR imaging

    International Nuclear Information System (INIS)

    Fujii, Shinya; Kido, Aki; Baba, Tsukasa; Fujimoto, Koji; Daido, Sayaka; Matsumura, Noriomi; Konishi, Ikuo; Togashi, Kaori

    2015-01-01

    Highlights: •We have assessed the peritumoral enhancement (PTE), which mimics SEE on DCE. •We evaluated the diagnostic accuracy of SEE for the myometrial invasion and the frequency of PTE. •We assessed the relationship between these enhancements and important pathologic factors. •PTE Type 1 is the main factor causing the overestimation of myometrial invasion using SEE on DCE. •PTE Type 2 correlates the myometrial invasion and may play an important role in the diagnosis of LVSI. -- Abstract: Objectives: To evaluate the diagnostic accuracy of subendometrial enhancement (SEE) in assessing the myometrial invasion in endometrial cancer, the frequency and clinical significance of peritumoral enhancement (PTE) on dynamic contrast enhanced (DCE) imaging. Materials and methods: MR images of 147 patients with endometrial cancer were retrospectively analyzed for intact SEE and PTEs: Type 1, a focal early enhancement peritumorally, and Type 2, an irregular thin-layered early intense enhancement peritumorally. Two radiologists independently assessed intact SEE and PTEs on DCE imaging and compared the lesions by the presence and depth of myometrial invasion, grade, lymphovascular space involvement (LVSI), and lymph node metastasis. The relationship between SEE, PTEs, and each factor was analyzed using univariate and multivariate analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for SEE. Results: The sensitivity, specificity, PPV, NPV and diagnostic accuracy for myometrial invasion based on SEE disruption on DCE were 96.6%, 32.1–46.4%, 85.8–88.5%, 69.2–76.5%, and 84.4–87.1%. According to multivariate analysis, SEE significantly predicted myometrial invasion (p < 0.0001). PTE Type 2 significantly predicted myometrial invasion presence (p < 0.05) and depth (p < 0.01). Conclusion: Diagnosis of myometrial invasion only by using SEE might be difficult on DCE-MRI due to the

  11. Enhanced Jumping-Droplet Departure.

    Science.gov (United States)

    Kim, Moon-Kyung; Cha, Hyeongyun; Birbarah, Patrick; Chavan, Shreyas; Zhong, Chen; Xu, Yuehan; Miljkovic, Nenad

    2015-12-15

    Water vapor condensation on superhydrophobic surfaces has received much attention in recent years because of its ability to shed water droplets at length scales 3 decades smaller than the capillary length (∼1 mm) via coalescence-induced droplet jumping. Jumping-droplet condensation has been demonstrated to enhance heat transfer, anti-icing, and self-cleaning efficiency and is governed by the theoretical inertial-capillary scaled jumping speed (U). When two droplets coalesce, the experimentally measured jumping speed (Uexp) is fundamentally limited by the internal fluid dynamics during the coalescence process (Uexp 2) coalescence as an avenue to break the two-droplet speed limit. Using side-view and top-view high-speed imaging to study more than 1000 jumping events on a copper oxide nanostructured superhydrophobic surface, we verify that droplet jumping occurs as a result of three fundamentally different mechanisms: (1) coalescence between two droplets, (2) coalescence among more than two droplets (multidroplet), and (3) coalescence between one or more droplets on the surface and a returning droplet that has already departed (multihop). We measured droplet-jumping speeds for a wide range of droplet radii (5-50 μm) and demonstrated that while the two-droplet capillary-to-inertial energy conversion mechanism is not identical to that of multidroplet jumping, speeds above the theoretical two-droplet limit (>0.23U) can be achieved. However, we discovered that multihop coalescence resulted in drastically reduced jumping speeds (≪0.23U) due to adverse momentum contributions from returning droplets. To quantify the impact of enhanced jumping speed on heat-transfer performance, we developed a condensation critical heat flux model to show that modest jumping speed enhancements of 50% using multidroplet jumping can enhance performance by up to 40%. Our results provide a starting point for the design of enhanced-performance jumping-droplet surfaces for industrial

  12. Enhancing who? Enhancing what? Ethics, bioethics, and transhumanism.

    Science.gov (United States)

    Koch, Tom

    2010-12-01

    Transhumanists advance a "posthuman" condition in which technological and genetic enhancements will transform humankind. They are joined in this goal by bioethicists arguing for genetic selection as a means of "enhancing evolution," improving if not also the species then at least the potential lives of future individuals. The argument of both, this paper argues, is a new riff on the old eugenics tune. As ever, it is done in the name of science and its presumed knowledge base. As ever, the result is destructive rather than instructive, bad faith promoted as high ideal. The paper concludes with the argument that species advancement is possible but in a manner thoroughly distinct from that advanced by either of these groups.

  13. PENGARUH ZPT TERHADAP KUALITAS BUAH MANGGIS

    Directory of Open Access Journals (Sweden)

    - Juanasri

    2008-09-01

    Full Text Available The objectives of this experiment was to examine the influence of polyamine, gibberelline and harvesting times to inhibit ripening process and to maintain postharvest quality on mangosteen. The method applied was randomized block design with two factors and three replications. First factor was harvesting time consisting of 14, 15 and 15 weeks after anthesis. Second factor is chemical concentration consisting of control (aquadest, GA3 (150, 200, 250 mg/l, polyamine (0,3; 1 and 3 mM. The result showed that spermidine application at 1 mM was more effective to maintain the postharvest quality of mangosteen, the fruit remained soft and the climacteric peak was longer than that of control. Gibberelline application showed unsightly result compared to control. Mangosteen fruits with harvesting time of 15 and 16 weeks after anthesis had better perfomance than those of harvesting at 14 weeks after anthesis, the fruit was remained soft and the weight lost was less.

  14. Contrast enhanced CT of spinal cord angioma

    International Nuclear Information System (INIS)

    Nakamura, Takahiko; Ebitani, Tsutomu; Honma, Takao; Sofue, Muroto; Nakamura, Shigeru

    1982-01-01

    Contrast enhanced CT on 6 patients with spinal cord angioma showed enhancement in 2 of them. The conditions to produce contrast enhancement were the window width of 100 - 200, and the window level of 0 - 50. In spinal cord angioma, contrast enhanced CT is presently only an adjunct to angiography and myelography. Nevertheless, contrast enhanced CT is useful in the screening test for spinal cord angioma, in the patients who are nonindicated to angiography, and in the postoperative follow-up. (Ueda, J.)

  15. Enhanced nonlinear frequency conversion and Purcell enhancement at exceptional points

    Science.gov (United States)

    Pick, Adi; Lin, Zin; Jin, Weiliang; Rodriguez, Alejandro W.

    2017-12-01

    Exceptional points (EPs) were recently predicted to modify the spontaneous emission rate or Purcell factor of narrow-band emitters embedded in resonant cavities. We demonstrate that EPs can have an even greater impact on nonlinear optical processes like frequency conversion by deriving a general formula quantifying radiative emission from a subwavelength emitter in the vicinity of a triply resonant χ(2 ) cavity that supports an EP near the emission frequency and a bright mode at the second harmonic. We show that the resulting frequency up-conversion process can be enhanced by up to two orders of magnitude compared to nondegenerate scenarios and that, in contrast to the recently predicted spontaneous-emission enhancements, nonlinear EP enhancements can persist even when considering spatial distributions of broadband emitters, provided that the cavity satisfies special nonlinear selection rules. This is demonstrated via a two-dimensional proof-of-concept PhC designed to partially fulfill the various criteria needed to approach the derived bounds on the maximum achievable up-conversion efficiencies. Our predictions suggest an indirect but practically relevant route to experimentally observe the impact of EPs on spontaneous emission, with implications to quantum information science.

  16. Malting of barley with combinations of Lactobacillus plantarum, Aspergillus niger, Trichoderma reesei, Rhizopus oligosporus and Geotrichum candidum to enhance malt quality.

    Science.gov (United States)

    Hattingh, M; Alexander, A; Meijering, I; van Reenen, C A; Dicks, L M T

    2014-03-03

    Good quality malt is characterised by the presence of high levels of fermentable sugars, amino acids and vitamins. To reach the starch-rich endosperm of the kernel, β-glucan- and arabinoxylan-rich cell walls have to be degraded. β-Glucanase is synthesized in vast quantities by the aleurone layer and scutellum during germination. Secretion of hydrolytic enzymes is often stimulated by addition of the plant hormone gibberellic acid (GA3) during germination. We have shown an enhanced β-glucanase and α-amylase activity in malt when germinating barley was inoculated with a combination of Lactobacillus plantarum B.S1.6 and spores of Aspergillus niger MH1, Rhizopus oligosporus MH2 or Trichoderma reesei MH3, and L. plantarum B.S1.6 combined with cell-free culture supernatants from each of these fungi. Highest malt β-glucanase activity (414 Units/kg malt) was recorded with a combination of L. plantarum B.S1.6 and spores of A. niger MH1. Highest α-amylase activities were recorded with a combination of L. plantarum B.S1.6 and spores of R. oligosporus MH2 (373 Ceralpha Units/g malt). Highest FAN levels were recorded when L. plantarum was inoculated in combination with spores of either R. oligosporus MH2 or T. reesei MH3 (259 and 260 ppm, respectively). This is the first study showing that cell-free culture supernatants of Aspergillus, Rhizopus and Trichoderma have a stimulating effect on β-glucanase and α-amylase production during malting. A combination of L. plantarum B.S1.6, and spores of A. niger MH1 and R. oligosporus MH2 may be used as starter cultures to enhance malt quality. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

    International Nuclear Information System (INIS)

    Xu Huixiong; Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu; Lu Mingde

    2010-01-01

    Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

  18. Gestures Enhance Foreign Language Learning

    Directory of Open Access Journals (Sweden)

    Manuela Macedonia

    2012-11-01

    Full Text Available Language and gesture are highly interdependent systems that reciprocally influence each other. For example, performing a gesture when learning a word or a phrase enhances its retrieval compared to pure verbal learning. Although the enhancing effects of co-speech gestures on memory are known to be robust, the underlying neural mechanisms are still unclear. Here, we summarize the results of behavioral and neuroscientific studies. They indicate that the neural representation of words consists of complex multimodal networks connecting perception and motor acts that occur during learning. In this context, gestures can reinforce the sensorimotor representation of a word or a phrase, making it resistant to decay. Also, gestures can favor embodiment of abstract words by creating it from scratch. Thus, we propose the use of gesture as a facilitating educational tool that integrates body and mind.

  19. Biosurfactant-enhanced soil bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Kosaric, N.; Lu, G.; Velikonja, J. [Univ. of Western Ontario, London, Ontario (Canada)

    1995-12-01

    Bioremediation of soil contaminated with organic chemicals is a viable alternative method for clean-up and remedy of hazardous waste sites. The final objective in this approach is to convert the parent toxicant into a readily biodegradable product which is harmless to human health and/or the environment. Biodegradation of hydrocarbons in soil can also efficiently be enhanced by addition or in-situ production of biosufactants. It was generally observed that the degradation time was shortened and particularly the adaptation time for the microbes. More data from our laboratories showed that chlorinated aromatic compounds, such as 2,4-dichlorophenol, a herbicide Metolachlor, as well as naphthalene are degraded faster and more completely when selected biosurfactants are added to the soil. More recent data demonstrated an enhanced biodegradation of heavy hydrocarbons in petrochemical sludges, and in contaminated oil when biosurfactants were present or were added prior to the biodegradation process.

  20. Hereditary syndromes with enhanced radiosensitivity

    International Nuclear Information System (INIS)

    Lohmann, D.

    2000-01-01

    Sensitivity to ionizing radiation is modified by heritable genetic factors. This is exemplified by heritable disorders that are characterized by predisposition to the development of neoplasms. Cells derived from patients with ataxia telangiectasia, Nijmegen breakage syndrome and ataxia telangiektasia-like disorder show a markedly changed reaction to exposure to ionizing radiation. Correspondingly, at least in patients with ataxia telangiectasia, an enhanced radiosensitivity that is of clinical importance has been observed. In addition to these recessive disorders, some autosomal dominant cancer predisposition syndromes are associated with increased radiosensitivity. As cells from these patients still have a normal allele (that is dominant over the mutant allele), the cellular phenotype is most often normal. Specifically, there is no overtly altered reaction in response to ionizing radiation. Nevertheless, two dominant cancer predisposition syndromes, namely hereditary retinoblastoma and naevoid basal cell carcinoma syndrome, are associated with a enhanced radiosensitivity as indicated by increased development of tumors following radiation therapy. (orig.) [de

  1. Enhancing aquifer cleanup with reinjection

    International Nuclear Information System (INIS)

    Isherwood, W.F.; Ziagos, J.; Rice, D. Jr.; Krauter, P.; Nichols, E.

    1992-09-01

    Injection of water or steam, with or without chemical surfactants, is a common petroleum industry technique to enhance product recovery. In the geothermal industry, reinjection (reinjection is used to mean the injection of ground water that was previously injected) of heat- depleted subsurface fluids is commonly used to maintain reservoir pressure, thus prolonging field productivity. The use reinjection in ground-water remediation projects allows for the application of both traditional production field management and a variety of additional enhancements to the cleanup process. Development of the ideas in this paper was stimulated by an initial suggestion by Dr. Jacob Bear (personal discussions, 1990--1991) that reinjected water might be heated to aid the desorption process

  2. Equipment improvements for performance enhancement

    International Nuclear Information System (INIS)

    Gaestel, P.; Guesnon, H.; Sauze, G.

    1994-01-01

    In order to enhance the reactor availability, several improvements on reactor equipment have been developed: design optimization for stator maintenance replacement in the main alternator; adjustment modification of stator coils in the main alternator for an easier maintenance; improvement of the fuel handling line (pole crane, transfer equipment, loading machine); development of a loose part trapping system in the steam generator secondary circuit. 1 tab

  3. Photodetector with enhanced light absorption

    Science.gov (United States)

    Kane, James

    1985-01-01

    A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

  4. Enhanced photochemistry on metal surfaces

    International Nuclear Information System (INIS)

    Goncher, G.M.; Parsons, C.A.; Harris, C.B.

    1984-01-01

    Due to the fast relaxation of molecular excited states in the vicinity of a metal or semiconductor surface, few observations of surface photochemistry have been reported. The following work concerns the surface-enhanced photo-reactions of a variety of physisorbed molecules on roughened Ag surfaces. In summary, photodecomposition leads to a graphitic surface carbon product which is monitored via surface-enhanced Raman scattering. In most cases an initial two-photon molecular absorption step followed by further absorption and fragmentation is thought to occur. Enhancement of the incident fields occurs through roughness-mediated surface plasmon resonances. This mechanism provides the amplified electromagnetic surface fields responsible for the observed photodecomposition. The photodecomposition experiments are performed under ultra-high vacuum. Surface characterization of the roughened surfaces was done by Scanning Electron Microscopy (SEM), and electron-stimulated emission. The SEM revealed morphology on the order of 300-400 A. This size of roughness feature, when modelled as isolated spheres should exhibit the well-known Mie resonances for light of the correct wavelengths. For protrusions existing on a surface these Mie resonances can be thought of as a coupling of the light with the surface plasmon. Experimental verification of these resonances was provided by the electron-stimulated light emission results. These showed that a polished Ag surface emitted only the expected transition radiation at the frequency of the Ag bulk plasmon. Upon roughening, however, a broad range of lower frequencies extending well into the visible are seen from electron irradiation of the surface. Large enhancements are expected for those frequencies which are able to couple into the surface modes

  5. Technology Education Professional Enhancement Project

    Science.gov (United States)

    Hughes, Thomas A., Jr.

    1996-01-01

    The two goals of this project are: the use of integrative field of aerospace technology to enhance the content and instruction delivered by math, science, and technology teachers through the development of a new publication entitled NASA Technology Today, and to develop a rationale and structure for the study of technology, which establishes the foundation for developing technology education standards and programs of the future.

  6. Convection-enhanced water evaporation

    OpenAIRE

    B. M. Weon; J. H. Je; C. Poulard

    2011-01-01

    Water vapor is lighter than air; this can enhance water evaporation by triggering vapor convection but there is little evidence. We directly visualize evaporation of nanoliter (2 to 700 nL) water droplets resting on silicon wafer in calm air using a high-resolution dual X-ray imaging method. Temporal evolutions of contact radius and contact angle reveal that evaporation rate linearly changes with surface area, indicating convective (instead of diffusive) evaporation in nanoliter water droplet...

  7. Plasmonics Enhanced Smartphone Fluorescence Microscopy

    KAUST Repository

    Wei, Qingshan

    2017-05-12

    Smartphone fluorescence microscopy has various applications in point-of-care (POC) testing and diagnostics, ranging from e.g., quantification of immunoassays, detection of microorganisms, to sensing of viruses. An important need in smartphone-based microscopy and sensing techniques is to improve the detection sensitivity to enable quantification of extremely low concentrations of target molecules. Here, we demonstrate a general strategy to enhance the detection sensitivity of a smartphone-based fluorescence microscope by using surface-enhanced fluorescence (SEF) created by a thin metal-film. In this plasmonic design, the samples are placed on a silver-coated glass slide with a thin spacer, and excited by a laser-diode from the backside through a glass hemisphere, generating surface plasmon polaritons. We optimized this mobile SEF system by tuning the metal-film thickness, spacer distance, excitation angle and polarization, and achieved ~10-fold enhancement in fluorescence intensity compared to a bare glass substrate, which enabled us to image single fluorescent particles as small as 50 nm in diameter and single quantum-dots. Furthermore, we quantified the detection limit of this platform by using DNA origami-based brightness standards, demonstrating that ~80 fluorophores per diffraction-limited spot can be readily detected by our mobile microscope, which opens up new opportunities for POC diagnostics and sensing applications in resource-limited-settings.

  8. Contrast-enhanced digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Dromain, Clarisse [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)], E-mail: dromain@igr.fr; Balleyguier, Corinne; Adler, Ghazal [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Garbay, Jean Remi [Department of Surgery, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Delaloge, Suzette [Department of Medicine, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)

    2009-01-15

    CEDM is a recent development of digital mammography using the intra-venous injection of an iodinated contrast agent in conjunction with a mammography examination. Two techniques have been developed to perform CEDM examinations: the temporal subtraction technique with acquisition of high-energy images before and after contrast medium injection and the dual energy technique with acquisition of a pair of low and high-energy images only after contrast medium injection. The temporal subtraction technique offered the possibility to analyze the kinetic curve of enhancement of breast lesions, similarly to breast MRI. The dual energy technique do not provide information about the kinetic of tumor enhancement but allows the acquisition of multiples views of the same breast or bilateral examination and is less sensitive to patient motion than temporal CEDM. Initial clinical experience has shown the ability of CEDM to map the distribution of neovasculature induced by cancer using mammography. Moreover, previous studies have shown a superiority of MX + CEDM, either for the assessment of the probability of malignancy than for BIRADS assessment comparing to MX alone. The potential clinical applications are the clarification of mammographically equivocal lesions, the detection of occult lesions on standard mammography, particularly in dense breast, the determination of the extent of disease, the assessment of recurrent disease and the monitoring of the response to chemotherapy. CEDM should result in a simple way to enhance the detection and the characterization of breast lesions.

  9. BNFL Magnox - Upgrades and enhancements

    International Nuclear Information System (INIS)

    Udbinac, M.J.

    2006-01-01

    In the past, generic models, restrictive budgets,and general shortages of resources have limited the scope of the UK's older Magnox simulators. Nevertheless, the simulators evolved slowly over time, becoming more like their reference plants, as resources became available. Three years ago, the Training and Development Branch of Magnox Electric plc took a giant leap, investing significant resources into the modernization of their training simulators. New hardware was built, including a new simulator room. The simulator software was ported from Unix running on outdated servers to new servers running Microsoft Windows NT. Perhaps most significantly, major model enhancements were made to key plant systems to significantly increase the likeness of each simulator to its reference plant. The upgrade to NT, the addition of state-of-the-art instructor stations, and some of the model enhancements were achieved with SimPort, an all-inclusive simulation package provided by DS and S. This paper will provide a more detailed view of the Magnox modular simulators, including how they are used and how they have benefited from the enhancements and upgrades implemented during the project. (author)

  10. Threshold enhancement of diphoton resonances

    Directory of Open Access Journals (Sweden)

    Aoife Bharucha

    2016-10-01

    Full Text Available We revisit a mechanism to enhance the decay width of (pseudo-scalar resonances to photon pairs when the process is mediated by loops of charged fermions produced near threshold. Motivated by the recent LHC data, indicating the presence of an excess in the diphoton spectrum at approximately 750 GeV, we illustrate this threshold enhancement mechanism in the case of a 750 GeV pseudoscalar boson A with a two-photon decay mediated by a charged and uncolored fermion having a mass at the 12MA threshold and a small decay width, <1 MeV. The implications of such a threshold enhancement are discussed in two explicit scenarios: i the Minimal Supersymmetric Standard Model in which the A state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through loops of charginos with masses close to 12MA and ii a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.

  11. Integrating diverse datasets improves developmental enhancer prediction.

    Directory of Open Access Journals (Sweden)

    Genevieve D Erwin

    2014-06-01

    Full Text Available Gene-regulatory enhancers have been identified using various approaches, including evolutionary conservation, regulatory protein binding, chromatin modifications, and DNA sequence motifs. To integrate these different approaches, we developed EnhancerFinder, a two-step method for distinguishing developmental enhancers from the genomic background and then predicting their tissue specificity. EnhancerFinder uses a multiple kernel learning approach to integrate DNA sequence motifs, evolutionary patterns, and diverse functional genomics datasets from a variety of cell types. In contrast with prediction approaches that define enhancers based on histone marks or p300 sites from a single cell line, we trained EnhancerFinder on hundreds of experimentally verified human developmental enhancers from the VISTA Enhancer Browser. We comprehensively evaluated EnhancerFinder using cross validation and found that our integrative method improves the identification of enhancers over approaches that consider a single type of data, such as sequence motifs, evolutionary conservation, or the binding of enhancer-associated proteins. We find that VISTA enhancers active in embryonic heart are easier to identify than enhancers active in several other embryonic tissues, likely due to their uniquely high GC content. We applied EnhancerFinder to the entire human genome and predicted 84,301 developmental enhancers and their tissue specificity. These predictions provide specific functional annotations for large amounts of human non-coding DNA, and are significantly enriched near genes with annotated roles in their predicted tissues and lead SNPs from genome-wide association studies. We demonstrate the utility of EnhancerFinder predictions through in vivo validation of novel embryonic gene regulatory enhancers from three developmental transcription factor loci. Our genome-wide developmental enhancer predictions are freely available as a UCSC Genome Browser track, which we hope

  12. Analyzing Security-Enhanced Linux Policy Specifications

    National Research Council Canada - National Science Library

    Archer, Myla

    2003-01-01

    NSA's Security-Enhanced (SE) Linux enhances Linux by providing a specification language for security policies and a Flask-like architecture with a security server for enforcing policies defined in the language...

  13. DENdb: database of integrated human enhancers

    KAUST Repository

    Ashoor, Haitham

    2015-09-05

    Enhancers are cis-acting DNA regulatory regions that play a key role in distal control of transcriptional activities. Identification of enhancers, coupled with a comprehensive functional analysis of their properties, could improve our understanding of complex gene transcription mechanisms and gene regulation processes in general. We developed DENdb, a centralized on-line repository of predicted enhancers derived from multiple human cell-lines. DENdb integrates enhancers predicted by five different methods generating an enriched catalogue of putative enhancers for each of the analysed cell-lines. DENdb provides information about the overlap of enhancers with DNase I hypersensitive regions, ChIP-seq regions of a number of transcription factors and transcription factor binding motifs, means to explore enhancer interactions with DNA using several chromatin interaction assays and enhancer neighbouring genes. DENdb is designed as a relational database that facilitates fast and efficient searching, browsing and visualization of information.

  14. Complementary surface charge for enhanced capacitive deionization

    NARCIS (Netherlands)

    Gao, X.; Porada, S.; Omosebi, A.; Liu, K.L.; Biesheuvel, P.M.; Landon, J.

    2016-01-01

    Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI

  15. Enhancing implementation security of QKD

    Science.gov (United States)

    Tamaki, Kiyoshi

    2017-10-01

    Quantum key distribution (QKD) can achieve information-theoretic security, which is a provable security against any eavesdropping, given that all the devices the sender and the receiver employ operate exactly as the theory of security requires. Unfortunately, however, it is difficult for practical devices to meet all such requirements, and therefore more works have to be done toward guaranteeing information-theoretic security in practice, i.e., implementation security. In this paper, we review our recent efforts to enhance implementation security. We also have a brief look at a flaw in security proofs and present how to fix it.

  16. Enhanced candu 6 reactor: status

    International Nuclear Information System (INIS)

    Azeez, S.; Girouard, P.

    2006-01-01

    The CANDU 6 power reactor is visionary in its approach, renowned for its on-power refuelling capability and proven over years of safe, economical and reliable power production. Developed by Atomic Energy of Canada Limited (AECL), the CANDU 6 design offers excellent performance utilizing state-of-the-art technology. The first CANDU 6 plants went into service in the early 1980s as leading edge technology and the design has been continuously advanced to maintain superior performance with an outstanding safety record. The first set of CANDU 6 plants - Gentilly 2 and Point Lepreau in Canada, Embalse in Argentina and Wolsong- Unit 1 in Korea - have been in service for more than 22 years and are still producing electricity at peak performance; to the end of 2004, their average Lifetime Capacity Factor was 83.2%. The newer CANDU 6 units in Romania (Cernavoda 1), Korea (Wolsong-Units 2, 3 and 4) and Qinshan (Phase III- Units 1 and 2) have also been performing at outstanding levels. The average lifetime Capacity Factor of the 10 CANDU 6 operating units around the world has been 87% to the end of 2004. Building on these successes, AECL is committed to the further development of this highly successful design, now focussing on meeting customers' needs for reduced costs, further improvements to plant operation and performance, enhanced safety and incorporating up-to-date technology, as warranted. This has resulted in AECL embarking on improving the CANDU 6 design through an upgraded product termed the ''Enhanced CANDU 6'' (EC6), which incorporates several attractive but proven features that make the CANDU 6 reactor even more economical, safer and easier to operate. Some of the key features that are being incorporated into the EC6 include increasing the plant's power output, shortening the overall project schedule, decreasing the capital cost, dealing with obsolescence issues, optimizing maintenance outages and incorporating lessons learnt through feedback obtained from the

  17. Gemstone enhancement by radiation treatment

    International Nuclear Information System (INIS)

    Desai, Shripal N.

    1998-01-01

    Since the discovery of radioactivity, investigations on the effects of atomic rays on precious stones began and Crookes established that alpha rays from radium produced green colour in diamonds. Gamma rays, x-rays, electrons, neutrons, protons etc. are effective in producing colour in precious stone like topaz and corundum. Some of these also produce considerable amount of radioactivity which is not acceptable if the radioactivity exceeds permissible limits. Colour enhancement by radiation treatment, different radiations, safety of irradiated gem stones and market related aspects are discussed. (author)

  18. ICT applications enhancing energy efficiency

    Directory of Open Access Journals (Sweden)

    A. G. Matani

    2016-06-01

    Full Text Available Computers, laptops and mobile devices – information technology (IT accounts for 2% of human greenhouse gas emissions worldwide, as evidenced in a study by Global Action Plan, a UK based environmental organization. This figure can be reduced if the green segment, or Green IT, continues to grow. Energy can also be saved through cloud computing, namely the principle of outsourcing the programs and functions of one’s own computer to service providers over the internet. This also means sharing storage capacity with others. This paper highlights the impact of information technology applications towards enhancing energy efficiency of the systems.

  19. Performance Enhancement by Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Parisa Gazerani

    2017-09-01

    Full Text Available Number of substances and strategies are available to increase performance in sport (Catlin and Murray, 1996. Since 2004, the World Anti-Doping Agency (WADA posts an updated list of substances and methods prohibited to athletes. Drugs (e.g., steroids, stimulants are a major part of this list; however, technologies and methods (e.g., gene doping are increasingly being identified and added (WADA, 2017. Among technologies and methods that might exert a potential effect on athletic performance, brain stimulation has recently been subjected to extensive discussion. Neuro-enhancement for doping purposes has been termed “neurodoping” in the literature (Davis, 2013; however, this concept needs further documentation before the term “neurodoping” can be used properly. Two major non-invasive techniques of brain stimulations are transcranial magnetic stimulation (TMS (Hallett, 2007; Rossi et al., 2009, and transcranial direct current stimulation (tDCS (Stagg and Nitsche, 2011. In TMS, an electric coil held over the head applies magnetic pulses to create currents in the brain. In tDCS, a low, continuous electrical current is delivered to the brain by using surface electrodes attached on the scalp. TMS and tDCS have been used in both research and clinic (Shin and Pelled, 2017 for example to examine alterations in cognitive function or motor skills or to assist in recovering motor function after a stroke (Gomez Palacio Schjetnan et al., 2013 or reducing fatigue in patients with multiple sclerosis (Saiote et al., 2014. In an opinion paper, it was proposed that use of emerging brain stimulation techniques might also enhance physical and mental performance in sports (Davis, 2013. The assumption was based on several reports. For example some studies have shown that TMS could shorten reaction times to visual, auditory and touch stimuli, reduce tremor, and enhance the acquisition of complex motor skills. Based on the current evidence, a recent review (Colzato

  20. Directing a Quality Enhancement Plan

    Directory of Open Access Journals (Sweden)

    Ronald A. Styron, Jr.

    2015-08-01

    Full Text Available This paper is drawn from a project aimed at enhancing the quality of instructional practice and improving studentlearning outcomes in classes across an urban university located in the southern region of the United States. The strategies, employed by the project leader, are discussed in detail as framed by a new problem-solving leadership design called the Alloy Improvement Model (AIM. Data collected at the end of the second full year and reported in this paper indicated all project goals were met and that the utilization of the AIM was central to project success.

  1. OVERCOMING SEED DORMANCY IN Annona macroprophyllata AND Annona purpureaUSING PLANT GROWTH REGULATORS

    Directory of Open Access Journals (Sweden)

    GISELA FERREIRA

    Full Text Available ABSTRACT Some Annonaceae seeds are known to exhibit dormancy mechanisms ranging from possible seed coat impermeability to physiological dormancy. Thus, the aim of this study was to evaluate the effects of gibberellin (GA GA3 and GA4+7 + benzyladenine (GA4+7 + BA application in seeds of Annona macroprophyllata Donn. Sm (papausa and Annona purpurea Moc. & Sessé ex Dunal (chincuya. The experiment was performed by the application of GA3 and GA4+7 + BA on seeds in concentrations of 0, 200, 400, 500, 600, 800 and 1000 mg L-1. The regulators broke the dormancy of both species. However, application of the GA4+7 + BA mixture had more significant results, with greater increases in germination in A. macroprophyllata than in A. purpurea. Treatments that promoted the highest germinations were GA4+7 + BA at a concentration of 200 mg L-1 for A. macroprophyllata (77% and 200 mg L-1 of GA4+7 + BA and 500 mg L-1 of GA3 for A. purpurea (30% and 29%, respectively. Rate index, mean time and frequency of germination were distinct for both species and both treatments. Although both GA3 and GA4+7 + BA promote germination, the GA4+7 + BA mixture was more effective than GA3 to overcoming seed dormancy of both species, A. purpurea has a harder dormancy than A. macroprophyllata

  2. Elongation growth of the leaf sheath base of Avena sativa seedlings: regulation by hormones and sucrose

    Science.gov (United States)

    Brock, T. G.; Kaufman, P. B.

    1991-01-01

    The leaf sheath base of the seedling of Avena sativa was characterized for growth response to hormones and sucrose. Six day old plants, raised under a 10:14 hr light:dark cycle, were excised at the coleoptilar node and 1 cm above the node for treatment. The growth of the leaf sheath base was promoted by gibberellic acid (GA3) and this response was dose dependent. The lag to response initiation was approximately 4 hr. Growth with or without GA3 (10 micromoles) was transient, diminishing appreciably after 48 hr. The addition of 10 mM sucrose greatly prolonged growth; the effect of GA3 and sucrose was additive. Neither indole-3-acetic acid (IAA) nor the cytokinin N6-benzyladenine (BA), alone or in combination, promoted the growth of leaf sheath bases. However, both significantly inhibited the action of GA3. The inhibitory effect of IAA was dose dependent and was not affected by the addition of BA or sucrose. These results indicate that the growth of leaf sheath bases of Avena sativa is promoted specifically by gibberellin, that this action depends on the availability of carbohydrates from outside of the leaf sheath base, and that the promotional effect of GA3 can be modified by either auxins or cytokinins.

  3. The endogenous plant hormones and ratios regulate sugar and dry matter accumulation in Jerusalem artichoke in salt-soil.

    Science.gov (United States)

    Li, Lingling; Shao, Tianyun; Yang, Hui; Chen, Manxia; Gao, Xiumei; Long, Xiaohua; Shao, Hongbo; Liu, Zhaopu; Rengel, Zed

    2017-02-01

    The changes in content of endogenous hormones in stolons and tubers of Jerusalem artichoke (Helianthus tuberosus L.) regulate tuber growth, but the specific knowledge about the importance of balance among the endogenous hormones is lacking. Two varieties of Jerusalem artichoke (NY-1 and QY-2) were tested for the endogenous zeatin (ZT), auxins (IAA), gibberellins (GA 3 ) and abscisic acid (ABA) in regulating sugar and dry matter accumulation in tubers. The dry matter content and sugar accumulation in tubers were correlated positively with endogenous ZT and negatively with GA 3 content and GA 3 /ABA and IAA/ABA content ratios. Throughout the tuber formation, ZT content was higher in NY-1 than QY-2 tubers, whereas ABA content was higher in QY-2 than NY-1 tubers. The content ratios GA 3 /ABA and IAA/ABA were greater in NY-1 than QY-2 before tuber initiation, but QY-2 surpassed NY-1 during the tuber growth stage. The GA 3 /ABA and IAA/ABA content ratios declined during tuber growth. The results suggested that a dynamic balance of endogenous hormones played an important role in tuber development. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Fibronectin enhances transfection of Staphylococcus aureus.

    OpenAIRE

    Thompson, N E; Bergdoll, M S; Pattee, P A

    1985-01-01

    The factor in normal sera primarily responsible for the enhancement of transfection (and transformation) of Staphylococcus aureus was identified as fibronectin. Serum samples which were depleted of fibronectin by affinity chromatography showed a marked decrease in enhancing activity. Fibronectin isolated from sera of several animal species demonstrated enhancing activity.

  5. Textual Enhancement of Input: Issues and Possibilities

    Science.gov (United States)

    Han, ZhaoHong; Park, Eun Sung; Combs, Charles

    2008-01-01

    The input enhancement hypothesis proposed by Sharwood Smith (1991, 1993) has stimulated considerable research over the last 15 years. This article reviews the research on textual enhancement of input (TE), an area where the majority of input enhancement studies have aggregated. Methodological idiosyncrasies are the norm of this body of research.…

  6. Visualization of enhancer-derived noncoding RNA

    CSIR Research Space (South Africa)

    Shibayama, Y

    2017-01-01

    Full Text Available Enhancers are principal regulators that allow spatiotemporal tissue-specifi c control of gene expression. While mounting evidence suggests that enhancer-derived long noncoding RNAs (long ncRNAs), including enhancer RNAs (eRNAs), are an important...

  7. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann

    2012-01-01

    We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission...

  8. Chemical Penetration Enhancers for Transdermal Drug Delivery ...

    African Journals Online (AJOL)

    for transdermal administration. The permeation of drug through skin can be enhanced by both chemical penetration enhancement and physical methods. In this review, we have discussed the chemical penetration enhancement technology for transdermal drug delivery as well as the probable mechanisms of action.

  9. Enhancing production of high-quality seed in Swedish conifer breeding

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Urban [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

    1996-12-31

    The main objective of this work was to develop and evaluate methods for increasing genetic control in the production of improved material in field-grown seed orchards. Supplemental mass pollination (SMP) and flower induction (stem injection of gibberellin A{sub 4/7}) were studied in two Pinus sylvestris L. orchards, while flower induction (stem injection and root pruning) were studied in three orchards of Picea abies (L.) Karst. SMP success rates, studied by means of allozyme markers, varied between 66% and 84% in a methods study in which pollen was applied close to each single strobilus. A single pollination of a strobilus at peak receptivity was sufficient to obtain high success rates. Root pruning significantly increased female flowering in two of the P. abies orchards, while stem injections of the gibbrellin induced a significant increase in one of these orchards. In two orchards the increase in number of cones was approximately threefold. Neither treatment had a significant effect on male flowering, and no interactions were found between treatments in the P. abies orchards. Stem injection on P. sylvestris grafts significantly increased seed and pollen production in one experiment each. Seed weight was significantly reduced by the stem injections in both P. sylvestris orchards. Significant clonal differences were found for all tested variables. No damage on the grafts was found that could be attributed to the gibberellin treatments. The results indicate that SMP and flower promotion methods can have practical value in seed orchard management. However, a full exploitation of the potential genetic gain from the improvement of the breeding populations will require the development of seed production concepts more advanced than those upon which current orchards are based. 163 refs, 5 figs, 1 tab

  10. RTU Comparison Calculator Enhancement Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Weimin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Katipamula, Srinivas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-01

    Over the past two years, Department of Energy’s Building Technologies Office (BTO) has been investigating ways to increase the operating efficiency of the packaged rooftop units (RTUs) in the field. First, by issuing a challenge to the RTU manufactures to increase the integrated energy efficiency ratio (IEER) by 60% over the existing ASHRAE 90.1-2010 standard. Second, by evaluating the performance of an advanced RTU controller that reduces the energy consumption by over 40%. BTO has previously also funded development of a RTU comparison calculator (RTUCC). RTUCC is a web-based tool that provides the user a way to compare energy and cost savings for two units with different efficiencies. However, the RTUCC currently cannot compare savings associated with either the RTU Challenge unit or the advanced RTU controls retrofit. Therefore, BTO has asked PNNL to enhance the tool so building owners can compare energy and savings associated with this new class of products. This document provides the details of the enhancements that are required to support estimating energy savings from use of RTU challenge units or advanced controls on existing RTUs.

  11. RTU Comparison Calculator Enhancement Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James D.; Wang, Weimin; Katipamula, Srinivas

    2014-03-31

    Over the past two years, Department of Energy’s Building Technologies Office (BTO) has been investigating ways to increase the operating efficiency of the packaged rooftop units (RTUs) in the field. First, by issuing a challenge to the RTU manufactures to increase the integrated energy efficiency ratio (IEER) by 60% over the existing ASHRAE 90.1-2010 standard. Second, by evaluating the performance of an advanced RTU controller that reduces the energy consumption by over 40%. BTO has previously also funded development of a RTU comparison calculator (RTUCC). RTUCC is a web-based tool that provides the user a way to compare energy and cost savings for two units with different efficiencies. However, the RTUCC currently cannot compare savings associated with either the RTU Challenge unit or the advanced RTU controls retrofit. Therefore, BTO has asked PNNL to enhance the tool so building owners can compare energy and savings associated with this new class of products. This document provides the details of the enhancements that are required to support estimating energy savings from use of RTU challenge units or advanced controls on existing RTUs.

  12. Enhancing avifauna in commercial plantations.

    Science.gov (United States)

    Nájera, Andrea; Simonetti, Javier A

    2010-02-01

    The occurrence of fauna in commercial plantations is often associated with structural complexity. Through a meta-analysis, we tested whether the structural complexity of plantations could enhance bird species assemblages and whether bird assemblages respond differently depending on taxonomic affiliation, body size, and diet. Our analyses included 167 case studies in 31 countries in which bird assemblages in forests and plantations were compared and 42 case studies in 14 countries in which bird assemblages in plantations of different structural complexity were compared. Species richness, but not abundance, was higher in forests than in plantations. Both species richness and abundance were significantly higher in complex than in structurally simple plantations. Taxonomic representation and body size did not differ between forest and plantations, except that there were fewer insectivorous birds in plantations than in forests. In the comparison of simple versus complex plantations, abundance of all taxonomic and dietary groups was higher in complex plantations. Body size did not affect bird species richness or abundance. Independent of the type of plantation, bird richness and abundance were greater in structurally complex plantations. Enhancing the structural complexity of plantations may mitigate their impact and offer habitat for some native species.

  13. Psychopharmacological enhancement: a conceptual framework.

    Science.gov (United States)

    Stein, Dan J

    2012-01-13

    The availability of a range of new psychotropic agents raises the possibility that these will be used for enhancement purposes (smart pills, happy pills, and pep pills). The enhancement debate soon raises questions in philosophy of medicine and psychiatry (eg, what is a disorder?), and this debate in turn raises fundament questions in philosophy of language, science, and ethics. In this paper, a naturalistic conceptual framework is proposed for addressing these issues. This framework begins by contrasting classical and critical concepts of categories, and then puts forward an integrative position that is based on cognitive-affective research. This position can in turn be used to consider the debate between pharmacological Calvinism (which may adopt a moral metaphor of disorder) and psychotropic utopianism (which may emphasize a medical metaphor of disorder). I argue that psychiatric treatment of serious psychiatric disorders is justified, and that psychotropics are an acceptable kind of intervention. The use of psychotropics for sub-threshold phenomena requires a judicious weighing of the relevant facts (which are often sparse) and values.

  14. Psychopharmacological enhancement: a conceptual framework

    Directory of Open Access Journals (Sweden)

    Stein Dan J

    2012-01-01

    Full Text Available Abstract The availability of a range of new psychotropic agents raises the possibility that these will be used for enhancement purposes (smart pills, happy pills, and pep pills. The enhancement debate soon raises questions in philosophy of medicine and psychiatry (eg, what is a disorder?, and this debate in turn raises fundament questions in philosophy of language, science, and ethics. In this paper, a naturalistic conceptual framework is proposed for addressing these issues. This framework begins by contrasting classical and critical concepts of categories, and then puts forward an integrative position that is based on cognitive-affective research. This position can in turn be used to consider the debate between pharmacological Calvinism (which may adopt a moral metaphor of disorder and psychotropic utopianism (which may emphasize a medical metaphor of disorder. I argue that psychiatric treatment of serious psychiatric disorders is justified, and that psychotropics are an acceptable kind of intervention. The use of psychotropics for sub-threshold phenomena requires a judicious weighing of the relevant facts (which are often sparse and values.

  15. An enhanced splined saddle method

    Science.gov (United States)

    Ghasemi, S. Alireza; Goedecker, Stefan

    2011-07-01

    We present modifications for the method recently developed by Granot and Baer [J. Chem. Phys. 128, 184111 (2008)], 10.1063/1.2916716. These modifications significantly enhance the efficiency and reliability of the method. In addition, we discuss some specific features of this method. These features provide important flexibilities which are crucial for a double-ended saddle point search method in order to be applicable to complex reaction mechanisms. Furthermore, it is discussed under what circumstances this methods might fail to find the transition state and remedies to avoid such situations are provided. We demonstrate the performance of the enhanced splined saddle method on several examples with increasing complexity, isomerization of ammonia, ethane and cyclopropane molecules, tautomerization of cytosine, the ring opening of cyclobutene, the Stone-Wales transformation of the C60 fullerene, and finally rolling a small NaCl cube on NaCl(001) surface. All of these calculations are based on density functional theory. The efficiency of the method is remarkable in regard to the reduction of the total computational time.

  16. Enhancing poxvirus vectors vaccine immunogenicity.

    Science.gov (United States)

    García-Arriaza, Juan; Esteban, Mariano

    2014-01-01

    Attenuated recombinant poxvirus vectors expressing heterologous antigens from pathogens are currently at various stages in clinical trials with the aim to establish their efficacy. This is because these vectors have shown excellent safety profiles, significant immunogenicity against foreign expressed antigens and are able to induce protective immune responses. In view of the limited efficacy triggered by some poxvirus strains used in clinical trials (i.e, ALVAC in the RV144 phase III clinical trial for HIV), and of the restrictive replication capacity of the highly attenuated vectors like MVA and NYVAC, there is a consensus that further improvements of these vectors should be pursuit. In this review we considered several strategies that are currently being implemented, as well as new approaches, to improve the immunogenicity of the poxvirus vectors. This includes heterologous prime/boost protocols, use of co-stimulatory molecules, deletion of viral immunomodulatory genes still present in the poxvirus genome, enhancing virus promoter strength, enhancing vector replication capacity, optimizing expression of foreign heterologous sequences, and the combined use of adjuvants. An optimized poxvirus vector triggering long-lasting immunity with a high protective efficacy against a selective disease should be sought.

  17. ENPEP model enhancements at ANL

    International Nuclear Information System (INIS)

    Guziel, K.A.

    1997-01-01

    Argonne National Laboratory (ANL) has been involved in energy and electricity planning analyses for almost 20 years. Their activities include the development of analytical tools and methodologies along with their application to a wide variety of national energy planning studies. The methodologies cover all aspects of energy planning. In response to a request by the US Department of Energy (USDOE) to integrate existing tools into a package that could be distributed to developing countries for their own use, the ENergy and Power Evaluation Program (ENPEP) was developed. The USDOE wanted an all purpose tool that would allow the user to do a complete energy analysis, from demand forecast through primary energy resources allocation to electricity generation system expansion plan and environmental analysis. Since its original development, the ENPEP modules have been improved and enhanced to incorporate advancements in computer hardware and software technology, as well as to correct bugs that were identified in the programs. In cooperation with other organizations (e.g. The World Bank - IBRD - and the International Atomic Energy Agency - IAEA -), the ENPEP package has been used at national, regional and inter-regional training courses, as well as in the conduct of national energy/electricity planning studies. This paper reviews the development of the ENPEP package and the proposed enhancements to the package. (author). 1 fig., 2 tabs

  18. Enhanced Video-Oculography System

    Science.gov (United States)

    Moore, Steven T.; MacDougall, Hamish G.

    2009-01-01

    A previously developed video-oculography system has been enhanced for use in measuring vestibulo-ocular reflexes of a human subject in a centrifuge, motor vehicle, or other setting. The system as previously developed included a lightweight digital video camera mounted on goggles. The left eye was illuminated by an infrared light-emitting diode via a dichroic mirror, and the camera captured images of the left eye in infrared light. To extract eye-movement data, the digitized video images were processed by software running in a laptop computer. Eye movements were calibrated by having the subject view a target pattern, fixed with respect to the subject s head, generated by a goggle-mounted laser with a diffraction grating. The system as enhanced includes a second camera for imaging the scene from the subject s perspective, and two inertial measurement units (IMUs) for measuring linear accelerations and rates of rotation for computing head movements. One IMU is mounted on the goggles, the other on the centrifuge or vehicle frame. All eye-movement and head-motion data are time-stamped. In addition, the subject s point of regard is superimposed on each scene image to enable analysis of patterns of gaze in real time.

  19. Threshold enhancement of diphoton resonances

    CERN Document Server

    Bharucha, Aoife; Goudelis, Andreas

    2016-10-10

    The data collected by the LHC collaborations at an energy of 13 TeV indicates the presence of an excess in the diphoton spectrum that would correspond to a resonance of a 750 GeV mass. The apparently large production cross section is nevertheless very difficult to explain in minimal models. We consider the possibility that the resonance is a pseudoscalar boson $A$ with a two--photon decay mediated by a charged and uncolored fermion having a mass at the $\\frac12 M_A$ threshold and a very small decay width, $\\ll 1$ MeV; one can then generate a large enhancement of the $A\\gamma\\gamma$ amplitude which explains the excess without invoking a large multiplicity of particles propagating in the loop, large electric charges and/or very strong Yukawa couplings. The implications of such a threshold enhancement are discussed in two explicit scenarios: i) the Minimal Supersymmetric Standard Model in which the $A$ state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through...

  20. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  1. Enhancing protection for vulnerable waters

    Science.gov (United States)

    Creed, Irena F.; Lane, Charles R.; Serran, Jacqueline N.; Alexander, Laurie C.; Basu, Nandita B.; Calhoun, Aram J. K.; Christensen, Jay R.; Cohen, Matthew J.; Craft, Christopher; D'Amico, Ellen; Dekeyser, Edward; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lang, Megan; Leibowitz, Scott G.; Lewis, David B.; Marton, John; McLaughlin, Daniel L.; Raanan-Kiperwas, Hadas; Rains, Mark C.; Rains, Kai C.; Smith, Lora

    2017-11-01

    Governments worldwide do not adequately protect their limited freshwater systems and therefore place freshwater functions and attendant ecosystem services at risk. The best available scientific evidence compels enhanced protections for freshwater systems, especially for impermanent streams and wetlands outside of floodplains that are particularly vulnerable to alteration or destruction. New approaches to freshwater sustainability -- implemented through scientifically informed adaptive management -- are required to protect freshwater systems through periods of changing societal needs. One such approach introduced in the US in 2015 is the Clean Water Rule, which clarified the jurisdictional scope for federally protected waters. However, within hours of its implementation litigants convinced the US Court of Appeals for the Sixth Circuit to stay the rule, and the subsequently elected administration has now placed it under review for potential revision or rescission. Regardless of its outcome at the federal level, policy and management discussions initiated by the propagation of this rare rulemaking event have potential far-reaching implications at all levels of government across the US and worldwide. At this timely juncture, we provide a scientific rationale and three policy options for all levels of government to meaningfully enhance protection of these vulnerable waters. A fourth option, a 'do-nothing' approach, is wholly inconsistent with the well-established scientific evidence of the importance of these vulnerable waters.

  2. Interspecific Difference in α-Amylase Production by the Endosperm in the Genus Avena

    OpenAIRE

    Ogawa, Yukiyoshi; Tachibana, Shoji; 小川, 幸持; 橘, 昌司

    1997-01-01

    Seeds of different diploid, tetraploid and hexaploid Avena species, stored for eight to nine months after harvesting, were cut transversely into two pieces at three different distances from the base of embryo attachment. Embryonated and embryoless endosperm pieces of three different sizes thus prepared were compared for the ability to produce α-amylase in the absence and presence of gibberellin A3(GA3). The abitity of the endosperm for α-amylase production was estimated by the activity of α-a...

  3. Meningeal enhancement on MRI after craniotomy

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Motohiro; Hasegawa, Mitsuhiro; Yamashima, Tetsumori; Yamashita, Junkoh; Suzuki, Masayuki (Kanazawa Univ. (Japan). School of Medicine)

    1991-08-01

    Gd-DPTA-enhanced MR images in 94 patients who had undergone craniotomy were studied, with particular attention paid to the meningeal enhancement. Such enhancement was noted in 26 of the 94 (27.6%) in the portion surrounding the craniotomy site. Meningeal enhancement, presumably of the subdural neomembrane, was apparent as a third line of a high signal intensity on T{sub 1}-weighted MR images. The outer two high-intensity lines were derived from fat in the subcutaneous tissues of the scalp and fat in the bone marrow of the calvaria. We designated this characteristic enhancement as a 'triple white line'. Of the 26 patients with meningeal enhancement, 22 cases (23.4%) showed such a 'triple white line', 11 cases (11.7%) showed falx enhancement, and 12 cases (12.8%) showed tentorial enhancement. The intervals between surgery and the appearance of the meningeal enhancement ranged from 4 days to 88 weeks. A small amount of bleeding into the dura-arachnoid interface induced by surgery might result in the subdural neomembrane, as has previously been reported. This neomembrane might be enhanced by the leakage of Gd-DTPA through the proliferating capillaries. As meningeal enhancement occurs in approximately a third of the cases following craniotomy, much care should be taken in the differential diagnosis of the infection, inflammation, and metastasis or dissemination of malignant brain tumors. (author).

  4. Meningeal enhancement on MRI after craniotomy

    International Nuclear Information System (INIS)

    Nomura, Motohiro; Hasegawa, Mitsuhiro; Yamashima, Tetsumori; Yamashita, Junkoh; Suzuki, Masayuki

    1991-01-01

    Gd-DPTA-enhanced MR images in 94 patients who had undergone craniotomy were studied, with particular attention paid to the meningeal enhancement. Such enhancement was noted in 26 of the 94 (27.6%) in the portion surrounding the craniotomy site. Meningeal enhancement, presumably of the subdural neomembrane, was apparent as a third line of a high signal intensity on T 1 -weighted MR images. The outer two high-intensity lines were derived from fat in the subcutaneous tissues of the scalp and fat in the bone marrow of the calvaria. We designated this characteristic enhancement as a 'triple white line'. Of the 26 patients with meningeal enhancement, 22 cases (23.4%) showed such a 'triple white line', 11 cases (11.7%) showed falx enhancement, and 12 cases (12.8%) showed tentorial enhancement. The intervals between surgery and the appearance of the meningeal enhancement ranged from 4 days to 88 weeks. A small amount of bleeding into the dura-arachnoid interface induced by surgery might result in the subdural neomembrane, as has previously been reported. This neomembrane might be enhanced by the leakage of Gd-DTPA through the proliferating capillaries. As meningeal enhancement occurs in approximately a third of the cases following craniotomy, much care should be taken in the differential diagnosis of the infection, inflammation, and metastasis or dissemination of malignant brain tumors. (author)

  5. Voluntary attention enhances contrast appearance.

    Science.gov (United States)

    Liu, Taosheng; Abrams, Jared; Carrasco, Marisa

    2009-03-01

    Voluntary (endogenous, sustained) covert spatial attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. We asked whether voluntary attention affects the subjective appearance of contrast--a fundamental dimension of visual perception. We used a demanding rapid serial visual presentation (RSVP) task to direct endogenous attention to a given location and measured perceived contrast at the attended and unattended locations. Attention increased perceived contrast of suprathreshold stimuli and also improved performance on a concurrent orientation discrimination task at the cued location. We ruled out response bias as an alternative account of the pattern of results. Thus, this study establishes that voluntary attention enhances perceived contrast. This phenomenological consequence links behavioral and neurophysiological studies on the effects of attention.

  6. Research for enhancing reactor safety

    International Nuclear Information System (INIS)

    1989-05-01

    Recent research for enhanced reactor safety covers extensive and numerous experiments and computed modelling activities designed to verify and to improve existing design requirements. The lectures presented at the meeting report GRS research results and the current status of reactor safety research in France. The GRS experts present results concerning expert systems and their perspectives in safety engineering, large-scale experiments and their significance in the development and verification of computer codes for thermohydraulic modelling of safety-related incidents, the advanced system code ATHLET for analysis of thermohydraulic processes of incidents, the analysis simulator which is a tool for fast evaluation of accident management measures, and investigations into event sequences and the required preventive emergency measures within the German Risk Study. (DG) [de

  7. Shale Oil Value Enhancement Research

    Energy Technology Data Exchange (ETDEWEB)

    James W. Bunger

    2006-11-30

    Raw kerogen oil is rich in heteroatom-containing compounds. Heteroatoms, N, S & O, are undesirable as components of a refinery feedstock, but are the basis for product value in agrochemicals, pharmaceuticals, surfactants, solvents, polymers, and a host of industrial materials. An economically viable, technologically feasible process scheme was developed in this research that promises to enhance the economics of oil shale development, both in the US and elsewhere in the world, in particular Estonia. Products will compete in existing markets for products now manufactured by costly synthesis routes. A premium petroleum refinery feedstock is also produced. The technology is now ready for pilot plant engineering studies and is likely to play an important role in developing a US oil shale industry.

  8. Photosynthesis solutions to enhance productivity.

    Science.gov (United States)

    Foyer, Christine H; Ruban, Alexander V; Nixon, Peter J

    2017-09-26

    The concept that photosynthesis is a highly inefficient process in terms of conversion of light energy into biomass is embedded in the literature. It is only in the past decade that the processes limiting photosynthetic efficiency have been understood to an extent that allows a step change in our ability to manipulate light energy assimilation into carbon gain. We can therefore envisage that future increases in the grain yield potential of our major crops may depend largely on increasing the efficiency of photosynthesis. The papers in this issue provide new insights into the nature of current limitations on photosynthesis and identify new targets that can be used for crop improvement, together with information on the impacts of a changing environment on the productivity of photosynthesis on land and in our oceans.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  9. The Game Enhanced Learning Model

    DEFF Research Database (Denmark)

    Reng, Lars; Schoenau-Fog, Henrik

    2016-01-01

    In this paper, we will introduce the Game Enhanced learning Model (GEM), which describes a range of gameoriented learning activities. The model is intended to give an overview of the possibilities of game-based learning in general and all the way up to purposive game productions. In the paper, we...... will describe the levels of the model, which is based on our experience in teaching professional game development at university level. Furthermore, we have been using the model to inspire numerous educators to improve their students’ motivation and skills. The model presents various game-based learning...... activities, and depicts their required planning and expected outcome through eight levels. At its lower levels, the model contains the possibilities of using stand-alone analogue and digital games as teachers, utilizing games as a facilitator of learning activities, exploiting gamification and motivating...

  10. Enhancing undergraduate students’ communications skills

    DEFF Research Database (Denmark)

    Jørgensen, Merete; Witt, Klaus; Fridorff-Jens, Peter Kindt

    2014-01-01

    19729 Abstract Title: Enhancing undergraduate students communications skills Abstract Authors: •Merete Jorgensen, Copenhagen University , Family Medicine , Copenhagen •Klaus Witt, Research Unit , Family Medicine , Copenhagen •Peter Kindt Fridorff-Jens, Copenhagen University , IT-unit , Copenhagen...... the Consultation Logic (CL) and Consultation Analysis (CA), based on the Patient-Centred Consultation. To investigate the effect of various teaching methods in communication skills we have developed a scientific tool (DanSCORE) based on CL and CA to measure the students analysing ability Summary of work It has...... and they alternate with five plus four hour’s sessions of assessing, analyzing and discussion the videos in small groups with a peer (university teacher) and fellow students.We focus in our project on communication skills. 600 medical students are enrolled in the project. Changes in analyzing ability...

  11. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    -state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged......In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast...... MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic...

  12. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncică, Ana Maria; Săftoiu, Adrian

    2011-01-01

    Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...... cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...

  13. Enhanced Li-Ion Battery

    Directory of Open Access Journals (Sweden)

    Natasha Ross

    2015-01-01

    Full Text Available Au with Pd nanoparticles were synthesized and coated onto the spinel LiMn2O4 via a coprecipitation calcination method with the objective to improve the microstructure, conductivity, and electrochemical activities of pristine LiMn2O4. The novel LiPdAuxMn2-xO4 composite cathode had high phase purity, well crystallized particles, and more regular morphological structures with narrow size distributions. At enlarged cycling potential ranges the LiPdAuxMn2-xO4 sample delivered 90 mAh g−1 discharge capacity compared to LiMn2O4 (45 mAh g−1. It was concluded that even a small amount of the Pd and Au enhanced both the lithium diffusivity and electrochemical conductivity of the host sample due to the beneficial properties of their synergy.

  14. Unrequited: neurochemical enhancement of love.

    Science.gov (United States)

    Bamford, Rebecca

    2015-07-01

    I raise several concerns with Earp and colleagues' analysis of enhancement through neurochemical modulation of love as a key issue in contemporary neuroethics. These include: (i) strengthening their deflation of medicalization concerns by showing how the objection that love should be left outside of the scope of medicine would directly undermine the goal of medicine; (ii) developing stronger analysis of the social and political concerns relevant to neurochemical modulation of love, by exploring and suggesting possible counters to ways in which 'wellbeing' may be used as a tool of oppression; (iii) providing reasons to support a broad need for ecological investigation of, and indeed ecological education concerning, neurotechnology; (iv) suggesting ways in which philosophy, and the humanities more broadly, remain directly relevant to responding effectively to issues in contemporary neuroethics.

  15. Enhanced NIF neutron activation diagnostics.

    Science.gov (United States)

    Yeamans, C B; Bleuel, D L; Bernstein, L A

    2012-10-01

    The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the (89)Zr/(89 m)Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

  16. Enhanced High Resolution RBS System

    Science.gov (United States)

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 Å TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron® accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  17. Enhancing undergraduate students’ communications skills

    DEFF Research Database (Denmark)

    Jørgensen, Merete; Witt, Klaus; Fridorff-Jens, Peter Kindt

    2014-01-01

    ,Monika Bullinger,Matthias Rose, Sylke Andreas.Enhancing medical students' communication skills: development and evaluation of an undergraduate training program.Published online 2012 March 24. doi: 10.1186/1472-6920-12-16 2.William T. Branch, Jr, MD; David Kern, MD; Paul Haidet, MD, MPH; Peter Weissmann, MD...... Abstract Presenter(s): •Merete Jorgensen, Copenhagen University , Family Medicine , Øster Farigmagsgade 5 , 1014 , K , Denmark , mejor@sund.ku.dk Abstract: Background Being teachers in Clinical Course of Family Medicine since 1995, we have developed two schemes for communication analysing purposes called...... and they alternate with five plus four hour’s sessions of assessing, analyzing and discussion the videos in small groups with a peer (university teacher) and fellow students.We focus in our project on communication skills. 600 medical students are enrolled in the project. Changes in analyzing ability...

  18. Enhanced performance hybrid-arq

    KAUST Repository

    Fareed, Muhammad Mehboob

    2016-06-16

    Apparatuses, computer readable media, and methods are provided for enhancing hybrid automatic repeat request (ARQ) performance. In an example method, a communication device transmits a first element of a vector, where the vector is selected using the information bits to be transmitted as an index in a code book. In some embodiments, this code book is constructed using Linear Constellation Precoding (LCP). If a NACK is received, the communication device transmits a second element of the vector. The process of transmitting elements of the vector continues until an ACK is received or the maximum number of transmission attempts is reached. If an ACK is received, the communication device transmits a first element of another vector of the code book that encodes a second set of information bits. This procedure may continue until all information bits have been transmitted successfully.

  19. Delayed enhanced MRI in intraparenchymal tumors

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

    1991-01-01

    Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

  20. Does groundwater enhance evaporative cooling?

    Science.gov (United States)

    Rouholahnejad, E.

    2015-12-01

    Evaporation is a key process in land-climate interactions, not only because it directly regulates the hydrological cycle, but also because it contributes to the Earth's energy balance. Due to its feedbacks on large-scale water processes and its impact on the dynamics of the atmosphere, it has been considered as a driver of droughts and heatwaves1-3. While evaporation from ocean surfaces is likely to increase with rising temperatures, it is unclear whether evapotranspiration from land surfaces could similarly increase, due to possible limitations imposed by soil moisture and vegetation physiology4. Observations suggest that groundwater (hereafter GW) has an important role in hydrological budgets and soil moisture variability in many regions, supplying moisture for evapotranspiration during dry seasons5, 6. Although modeling studies suggest that GW is often close enough to the surface to interact with the atmosphere7, 8, the soil water storage is often underestimated by land surface models. This is most likely due to neglecting the lateral movement of water from topographically higher altitudes to valley bottoms and its convergence close to the land surface, as well as the upward movement of water in the capillary fringe.The focus of this study is to understand where and when GW may significantly enhance the availability of soil water for evapotranspiration. We also quantified the potential contribution of GW to evapotranspiration in the areas where GW is a major supply. We used the global network of eddy covariance observations9 (FLUXNET) along with global modeled GW depth10 and GLEAM ET model estimates11 to address the current gap in modelling ET due to neglecting GW supply. Having identified areas where GW is tightly coupled with the atmosphere through evaporation processes, the study provides the basis to examine the "air conditioning effect" of GW and test the idea if GW enhances evaporation to the extent that leads to a cooler temperatures and wetter climates.

  1. Enhanced MRI in patients with facial palsy

    International Nuclear Information System (INIS)

    Yanagida, Masahiro; Kato, Tsutomu; Ushiro, Koichi; Kitajiri, Masanori; Yamashita, Toshio; Kumazawa, Tadami; Tanaka, Yoshimasa

    1991-01-01

    We performed Gd-DTPA-enhanced magnetic resonance imaging (MRI) examinations at several stages in 40 patients with peripheral facial nerve palsy (Bell's palsy and Ramsay-Hunt syndrome). In 38 of the 40 patients, one and more enhanced region could be seen in certain portion of the facial nerve in the temporal bone on the affected side, whereas no enhanced regions were seen on the intact side. Correlations between the timing of the MRI examination and the location of the enhanced regions were analysed. In all 6 patients examined by MRI within 5 days after the onset of facial nerve palsy, enhanced regions were present in the meatal portion. In 3 of the 8 patients (38%) examined by MRI 6 to 10 days after the onset of facial palsy, enhanced areas were seen in both the meatal and labyrinthine portions. In 8 of the 9 patients (89%) tested 11 to 20 days after the onset of palsy, the vertical portion was enhanced. In the 12 patients examined by MRI 21 to 40 days after the onset of facial nerve palsy, the meatal portion was not enhanced while the labyrinthine portion, the horizontal portion and the vertical portion were enhanced in 5 (42%), 8 (67%) and 11 (92%), respectively. Enhancement in the vertical portion was observed in all 5 patients examined more than 41 days after the onset of facial palsy. These results suggest that the central portion of the facial nerve in the temporal bone tends to be enhanced in the early stage of facial nerve palsy, while the peripheral portion is enhanced in the late stage. These changes of Gd-DTPA enhanced regions in the facial nerve may suggest dromic degeneration of the facial nerve in peripheral facial nerve palsy. (author)

  2. Phytoextraction of contaminated urban soils by Panicum virgatum L. enhanced with application of a plant growth regulator (BAP) and citric acid.

    Science.gov (United States)

    Aderholt, Matthew; Vogelien, Dale L; Koether, Marina; Greipsson, Sigurdur

    2017-05-01

    Lead (Pb) contamination in soil represents a threat to human health. Phytoextraction has gained attention as a potential alternative to traditional remediation methods because of lower cost and minimal soil disruption. The North American native switchgrass (Panicum virgatum L.) was targeted due to its ability to produce high biomass and grow across a variety of ecozones. In this study switchgrass was chemically enhanced with applications of the soil-fungicide benomyl, chelates (EDTA and citric acid), and PGR to optimize phytoextraction of Pb and zinc (Zn) from contaminated urban soils in Atlanta, GA. Exogenous application of two plant hormones was compared in multiple concentrations to determine effects on switchgrass growth: indole-3-acetic acid (IAA), and Gibberellic Acid (GA 3 ), and one PGR benzylaminopurine (BAP), The PGR BAP (1.0 μM) was found to generate a 48% increase in biomass compared to Control plants. Chemical application of citric acid, EDTA, benomyl, and BAP were tested separately and in combination in a pot experiment in an environmentally controlled greenhouse to determine the efficacy of phtyoextraction by switchgrass. Soil acidification by citric acid application resulted in highest level of aluminum (Al) and iron (Fe) in plants foliage resulting in severe phytotoxic effects. Total Pb phytoextraction was significantly highest in plants treated with combined chemical application of B + C and B + C + H. Suppression of AMF activities by benomyl application significantly increased concentrations of Al and Fe in roots. Application of benomyl reduced AMF colonization but was also shown to dramatically increase levels of septa fungi infection as compared to Control plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Detectability of hepatocellular carcinoma: comparison of Gd-DTPA-enhanced and SPIO-enhanced MR imaging

    International Nuclear Information System (INIS)

    Kwak, Hyo Sung; Lee, Jeong Min; Kim In Hwan; Kim, Chong Soo; Han, Hyeun Young; Yoon, Kwon ha; Shin, Kyung Sook

    2000-01-01

    To compare the detectability of hepatocellular carcinoma (HCC) using superparamagnetic iron oxide (SPIO)-enhanced T2-weighted turbo spin echo (TSE), SPIO-enhanced T2-weighted FISP, and dynamic Gd-DTPA-enhanced fast low-angle shot (FLASH) MR images. In order to assess their hepatic lesions, 25 patients (20 men and 5 women) with HCC were enrolled in an MR study in which both gadolinium and Spiro were used. Since the lesions were most conspicuous during the phase of dynamic arterial dominant phase of dynamic gadolinium-enhanced imaging, this was the phase used for analysis. Images were analyzed qualitatively and quantitatively, and to compare the diagnostic value of gadolinium-enhanced imaging with that of SPIO-enhanced imaging for the detection of HCCs, a receiver-operated characteristic curve was obtained. Qualitative analysis revealed a significantly higher percentage of signal loss and a higher liver-lesion contrast-to-noise ratio on SPIO-enhanced FISP imaging than on SPIO-enhanced T2-weighted TSE imaging (p less than 0.05). It also showed that the lesions were most clearly visible on SPIO-enhanced FISP imaging (and significantly so), followed by SPIO-enhanced T2-weighted TSE imaging, and dynamic gadolinium-enhanced imaging. Imaging artifacts were more prominent on SPIO-enhanced T2-weighted TSE than on SPIO-enhanced PISF imaging or dynamic gadolinium-enhanced imaging (p less than 0.05). According to ROC analysis, SPIO-enhanced T2-weighted turbo spin echo (TSE) or SPIO-enhanced FISP imaging achieved higher accuracy than did dynamic gadolinium-enhanced FLASH imaging (p less than 0.05). For the detection of hepatocellular carcinomas, SPIO-enhanced MR imaging is better than gadolinium-enhanced FLASH imaging

  4. Delta Relaxation Enhanced Magnetic Resonance

    Science.gov (United States)

    Alford, Jamu K.

    Generally speaking, targeted molecular imaging has always been difficult to perform with magnetic resonance. The difficulty does not arise with the magnetic resonance imaging (MRI) technique or equipment itself, but rather with the targeted contrast agents, which the method requires. Also referred to as activatable contrast agents, or MRI probes, targeted contrast agents are pharmaceuticals that will selectively bind to a particular biological (target) molecule. They are used to highlight a certain tissue or the difference between healthy and diseased tissue. Unfortunately, nearly all MRI probes are non-specific, causing localized increases in MR image intensity in both the unbound and target-bound states. Therefore, brightening in a conventional MRI image, following probe injection, does not positively indicate the presence of the target molecule. Herein, a novel method known as delta relaxation enhanced magnetic resonance (dreMR, pronounced "dreamer") is presented that utilizes variable magnetic field technology to produce image contrast related to the dependence of the sample's longitudinal relaxation rates upon the strength of the main magnetic field of the MRI scanner. Since only bound contrast agent shows significant magnetic field dependence, it is an indicator of the bound probe, which is in turn a marker for the target molecule. This work details the development of the dreMR method, focusing on the specialized hardware necessary to provide a clinical, static-field MRI the ability to modulate its main magnetic field throughout an MRI sequence. All modifications were performed in such a manner that the host MRI system was not degraded or permanently modified in any way. The three parts of this technology are: the insertable electromagnet, the power supply system and the control system. The insertable electromagnet modifies the magnetic field, the power system drives the electromagnet, and the control system generates the magnetic field waveform envelope and

  5. Cognitive enhancement. Effort of definition, and methods

    Directory of Open Access Journals (Sweden)

    Artur Gunia

    2015-12-01

    Full Text Available The idea of cognitive enhancement refers to multifaceted and interdisciplinary approach aimed at improving human mental processes. Cognitive enhancement is the amplification or extension of core mind capacities through improvement or augmentation of either internal or external information processing systems. This includes improvements of intelligence and attention, reinforcement of creativity and memory, or extension of perception range. The main feature of cognitive enhancement is voluntariness of use for overcoming natural mental limitations. This article is a synthesis of current trends in cognitive enhancement from the perspective of transhumanism. The article presents various definitions of cognitive enhancement, methods of cognitive enhancement (biotechnological methods, non-pharmacological methods, IT methods as well as challenges and questions concerning improving human mental processes.

  6. Comparative enhancing effects of electret with chemical enhancers on transdermal delivery of meloxicam in vitro

    International Nuclear Information System (INIS)

    Cui, L L; Hou, X M; Li, G D; Jiang, J; Liang, Y Y; Xin, X

    2008-01-01

    Electret offers enhancing effect in transdermal drug delivery for altering of the arrangement of lipid molecules in the stratum corneum, forming many transient permeable apertures and enhancing the transdermal drug delivery. In this paper, meloxicam patch formulations were developed to make the comparative study of transdermal drug delivery between electret and chemical enhancers. Patches were made into control, electret, chemical enhancer and electret with chemical enhancer ones, according to the preparation procedure. The electret combined with chemical enhancer patch was designed to probe the incorporation between electret and chemical enhancer in transdermal drug delivery. The meloxicam release from the patch was found to increase in order of blank, chemical enhancer, electret and electret with chemical enhancer patch, in general.

  7. DiseaseEnhancer: a resource of human disease-associated enhancer catalog.

    Science.gov (United States)

    Zhang, Guanxiong; Shi, Jian; Zhu, Shiwei; Lan, Yujia; Xu, Liwen; Yuan, Huating; Liao, Gaoming; Liu, Xiaoqin; Zhang, Yunpeng; Xiao, Yun; Li, Xia

    2018-01-04

    Large-scale sequencing studies discovered substantial genetic variants occurring in enhancers which regulate genes via long range chromatin interactions. Importantly, such variants could affect enhancer regulation by changing transcription factor bindings or enhancer hijacking, and in turn, make an essential contribution to disease progression. To facilitate better usage of published data and exploring enhancer deregulation in various human diseases, we created DiseaseEnhancer (http://biocc.hrbmu.edu.cn/DiseaseEnhancer/), a manually curated database for disease-associated enhancers. As of July 2017, DiseaseEnhancer includes 847 disease-associated enhancers in 143 human diseases. Database features include basic enhancer information (i.e. genomic location and target genes); disease types; associated variants on the enhancer and their mediated phenotypes (i.e. gain/loss of enhancer and the alterations of transcription factor bindings). We also include a feature on our website to export any query results into a file and download the full database. DiseaseEnhancer provides a promising avenue for researchers to facilitate the understanding of enhancer deregulation in disease pathogenesis, and identify new biomarkers for disease diagnosis and therapy. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Gd-enhanced MR imaging of the herniated lumbar disc: patterns of enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Kwag, Hyon Joo; Choi, Hye Young; Kim, Hyae Young; Kim, Yoo Kyung; Kim, Ah Young; Chung, Eun Chul [College of Medicine, Ewah Womans University, Seoul (Korea, Republic of)

    1995-07-15

    The purpose of this study is to describe the patterns of enhancement of the herniated lumbar disc with Gd-DTPA enhanced MR imaging. Out of 65 patients, 103 lumbar discs diagnosed to be herniated by MR image were retrospectively analyzed. The MR imaging was performed with 1.5 T MR unit, using T1-and T2-weighted sagittal and axial spin echo techniques. Contrast-enhanced T1 weighted sagittal and axial images were performed after intravenous injection of Gadopentetate-dimeglumine(Magnevist, Shering) (0.1 mmol/kg). Contrast enhancement was seen in 66 cases(64%). Thirteen cases of bulging disc were not enhanced. Twenty-eight cases of protruded disc showed intraannular enchantment in 23 cases, peripheral linear and irregular enhancement in each of one case, and nonenhancement in three cases. Fifty-seven cases of extruded disc showed irregular enhancement in 14 cases, peripheral linear enhancement in 12 cases, peripheral ring enhancement in five cases and intraannular enhancement in five cases. All five cases of sequestered disc showed peripheral ring enhancement. Protruded discs show intraannular enhancement frequently and sequestered discs usually show peripheral ring enhancement. Enhanced MR imaging may be helpful to evaluate the type of herniated lumbar disc and relationship among disc material, nerve root and thecal sac.

  9. Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bohyun [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Ajou University School of Medicine, Department of Radiology, Suwon (Korea, Republic of); Byun, Jae Ho; Kim, Hyoung Jung; Won, Hyung Jin; Kim, So Yeon; Shin, Yong Moon; Kim, Pyo Nyun [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

    2016-01-15

    To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL). On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP. Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP. Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups. (orig.)

  10. Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI

    International Nuclear Information System (INIS)

    Kim, Bohyun; Byun, Jae Ho; Kim, Hyoung Jung; Won, Hyung Jin; Kim, So Yeon; Shin, Yong Moon; Kim, Pyo Nyun

    2016-01-01

    To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL). On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP. Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP. Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups. (orig.)

  11. Gd-enhanced MR imaging of the herniated lumbar disc: patterns of enhancement

    International Nuclear Information System (INIS)

    Kwag, Hyon Joo; Choi, Hye Young; Kim, Hyae Young; Kim, Yoo Kyung; Kim, Ah Young; Chung, Eun Chul

    1995-01-01

    The purpose of this study is to describe the patterns of enhancement of the herniated lumbar disc with Gd-DTPA enhanced MR imaging. Out of 65 patients, 103 lumbar discs diagnosed to be herniated by MR image were retrospectively analyzed. The MR imaging was performed with 1.5 T MR unit, using T1-and T2-weighted sagittal and axial spin echo techniques. Contrast-enhanced T1 weighted sagittal and axial images were performed after intravenous injection of Gadopentetate-dimeglumine(Magnevist, Shering) (0.1 mmol/kg). Contrast enhancement was seen in 66 cases(64%). Thirteen cases of bulging disc were not enhanced. Twenty-eight cases of protruded disc showed intraannular enchantment in 23 cases, peripheral linear and irregular enhancement in each of one case, and nonenhancement in three cases. Fifty-seven cases of extruded disc showed irregular enhancement in 14 cases, peripheral linear enhancement in 12 cases, peripheral ring enhancement in five cases and intraannular enhancement in five cases. All five cases of sequestered disc showed peripheral ring enhancement. Protruded discs show intraannular enhancement frequently and sequestered discs usually show peripheral ring enhancement. Enhanced MR imaging may be helpful to evaluate the type of herniated lumbar disc and relationship among disc material, nerve root and thecal sac

  12. Surface-enhanced Raman spectroscopy: nonlocal limitations

    DEFF Research Database (Denmark)

    Toscano, Giuseppe; Raza, S.; Xiao, Sanshui

    2012-01-01

    for our understanding of surface-enhanced Raman spectroscopy (SERS). The intrinsic length scale of the electron gas serves to smear out assumed field singularities, leaving the SERS enhancement factor finite, even for geometries with infinitely sharp features. For silver nanogroove structures, mimicked...... by periodic arrays of half-cylinders (up to 120 nm in radius), we find no enhancement factors exceeding 10 orders of magnitude (10(10)). (C) 2012 Optical Society of America...

  13. Surface-enhanced Raman spectroscopy: nonlocal limitations

    DEFF Research Database (Denmark)

    Toscano, Giuseppe; Raza, Søren; Xiao, Sanshui

    2012-01-01

    for our understanding of surface-enhanced Raman spectroscopy (SERS). The intrinsic length scale of the electron gas serves to smear out assumed field singularities, leaving the SERS enhancement factor finite, even for geometries with infinitely sharp features. For silver nanogroove structures, mimicked...... by periodic arrays of half-cylinders (up to 120 nm in radius), we find no enhancement factors exceeding 10 orders of magnitude (1010)....

  14. Arousal-Enhanced Location Memory for Pictures

    OpenAIRE

    Mather, Mara; Nesmith, Kathryn

    2008-01-01

    Four experiments revealed arousal-enhanced location memory for pictures. After an incidental encoding task, participants were more likely to remember the locations of positive and negative arousing pictures than the locations of non-arousing pictures, indicating better binding of location to picture. This arousal-enhanced binding effect did not have a cost for the binding of nearby pictures to their locations. Thus, arousal can enhance binding of an arousing picture’s content to its location ...

  15. Multispectral Image Enhancement Through Adaptive Wavelet Fusion

    Science.gov (United States)

    2016-09-14

    AFRL-AFOSR-UK-TR-2017-0005 Multispectral image enhancement through adaptive wavelet fusion Alexander Toet Nederlandse Organisatie voor Toegepast...image enhancement through adaptive wavelet fusion 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-15-1-0433 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S...efficient. 15. SUBJECT TERMS adaptive wavelet fusion, Multispectral image enhancement, Multispectral image fusion, multiband image interpolation

  16. Contrast-enhanced sonography in pancreatic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Rickes, Steffen [Department of Internal Medicine, AMEOS Hospital GmbH, Halberstadt (Germany); Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke-University, Magdeburg (Germany)], E-mail: rickes@medkl.salvator-kh.de; Rauh, Peter; Uhle, Christine; Ensberg, Daniel [Department of Internal Medicine, AMEOS Hospital GmbH, Halberstadt (Germany); Moenkemueller, Klaus; Malfertheiner, Peter [Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke-University, Magdeburg (Germany)

    2007-11-15

    Contrast-enhanced sonography is a widely available imaging modality for the diagnosis of pancreatic diseases. With this procedure, pancreatic tumours can be differentiated better. Furthermore, contrast-enhanced sonography produces good results in the staging of acute pancreatitis severity, especially in the detection of pancreatic necrosis. In this review article the value of contrast-enhanced sonography in the diagnosis of pancreatic diseases will be described and discussed.

  17. Enhancement of colposcopic image by sulphosalicylic acid.

    Directory of Open Access Journals (Sweden)

    Khilnani P

    1993-01-01

    Full Text Available Acetic acid is used conventionally for enhancement of the colposcopic image. We used sulphosalicylic acid instead of acetic acid in 50 normal cases. The normal appearance was enhanced in all cases. The image was also enhanced in 70% cases of cervical intraepithelial neoplasia and 90% cases of cervical condyloma accuminata. The image was not inferior to that with acetic acid in any of the cases.

  18. Enhanced safeguards via solution monitoring

    International Nuclear Information System (INIS)

    Burr, T.; Wangen, L.

    1996-09-01

    Solution monitoring is defined as the essentially continuous monitoring of solution level, density, and temperature in all tanks in the process that contain, or could contain, safeguards-significant quantities of nuclear material. This report describes some of the enhancements that solution monitoring could make to international safeguards. The focus is on the quantifiable benefits of solution monitoring, but qualitatively, solution monitoring can be viewed as a form of surveillance. Quantitatively, solution monitoring can in some cases improve diversion detection probability. For example, the authors show that under certain assumptions, solution monitoring can be used to reduce the standard deviation of the annual material balance, σ MB , from approximately 17 kg to approximately 4 kg. Such reduction in σ MB will not always be possible, as they discuss. However, in all cases, solution monitoring would provide assurance that the measurement error models are adequate so that one has confidence in his estimate of σ MB . Some of the results in this report were generated using data that were simulated with prototype solution monitoring software that they are developing. An accompanying document describes that software

  19. Does facial resemblance enhance cooperation?

    Directory of Open Access Journals (Sweden)

    Trang Giang

    Full Text Available Facial self-resemblance has been proposed to serve as a kinship cue that facilitates cooperation between kin. In the present study, facial resemblance was manipulated by morphing stimulus faces with the participants' own faces or control faces (resulting in self-resemblant or other-resemblant composite faces. A norming study showed that the perceived degree of kinship was higher for the participants and the self-resemblant composite faces than for actual first-degree relatives. Effects of facial self-resemblance on trust and cooperation were tested in a paradigm that has proven to be sensitive to facial trustworthiness, facial likability, and facial expression. First, participants played a cooperation game in which the composite faces were shown. Then, likability ratings were assessed. In a source memory test, participants were required to identify old and new faces, and were asked to remember whether the faces belonged to cooperators or cheaters in the cooperation game. Old-new recognition was enhanced for self-resemblant faces in comparison to other-resemblant faces. However, facial self-resemblance had no effects on the degree of cooperation in the cooperation game, on the emotional evaluation of the faces as reflected in the likability judgments, and on the expectation that a face belonged to a cooperator rather than to a cheater. Therefore, the present results are clearly inconsistent with the assumption of an evolved kin recognition module built into the human face recognition system.

  20. Image enhancement for astronomical scenes

    Science.gov (United States)

    Lucas, Jacob; Calef, Brandoch; Knox, Keith

    2013-09-01

    Telescope images of astronomical objects and man-made satellites are frequently characterized by high dynamic range and low SNR. We consider the problem of how to enhance these images, with the aim of making them visually useful rather than radiometrically accurate. Standard contrast and histogram adjustment tends to strongly amplify noise in dark regions of the image. Sophisticated techniques have been developed to address this problem in the context of natural scenes. However, these techniques often misbehave when confronted with low-SNR scenes that are also mostly empty space. We compare two classes of algorithms: contrast-limited adaptive histogram equalization, which achieves spatial localization via a tiling of the image, and gradient-domain techniques, which perform localized contrast adjustment by non-linearly remapping the gradient of the image in a content-dependent manner. We extend these to include a priori knowledge of SNR and the processing (e.g. deconvolution) that was applied in the preparation of the image. The methods will be illustrated with images of satellites from a ground-based telescope.

  1. Facebook enhances antidepressant pharmacotherapy effects.

    Science.gov (United States)

    Mota Pereira, Jorge

    2014-01-01

    Treatment-resistant major depressive disorder (TR-MDD) is a complex condition, with very low remission rates. In recent years some studies have been conducted on the implementation of cognitive behavioral therapy and psychodynamic psychotherapy interventions via the Internet to MDD patients, and results have been promising. However, there have been no studies in patients with TR-MDD nor with the use of Facebook with the psychiatrist as "friend." 60 TR-MDD patients were randomized to one of three groups: Facebook group with psychiatrist as "friend," Facebook group without psychiatrist as "friend," and control group (no Facebook use). Both Facebook groups spent at least 1 hour/day on Facebook, 7 days/week, during the 3 months. All patients maintained their usual pharmacotherapy. All participants were evaluated at baseline and at 1, 2, and 3 months for depressive symptoms using HAD17 and BDI-II. Results show that both Facebook groups had a decrease on HADM17 and BDI-II scores as well as higher remission and response rates than the control group, with better results if the psychiatrist was a "friend" on Facebook. Therefore, in TR-MDD, Facebook can be used as an effective enhancement therapy, adjuvant to pharmacological therapy with regular consultations, especially if the psychiatrist is the patient's online "friend."

  2. An enhanced tokamak startup model

    Science.gov (United States)

    Goswami, Rajiv; Artaud, Jean-François

    2017-01-01

    The startup of tokamaks has been examined in the past in varying degree of detail. This phase typically involves the burnthrough of impurities and the subsequent rampup of plasma current. A zero-dimensional (0D) model is most widely used where the time evolution of volume averaged quantities determines the detailed balance between the input and loss of particle and power. But, being a 0D setup, these studies do not take into consideration the co-evolution of plasma size and shape, and instead assume an unchanging minor and major radius. However, it is known that the plasma position and its minor radius can change appreciably as the plasma evolves in time to fill in the entire available volume. In this paper, an enhanced model for the tokamak startup is introduced, which for the first time takes into account the evolution of plasma geometry during this brief but highly dynamic period by including realistic one-dimensional (1D) effects within the broad 0D framework. In addition the effect of runaway electrons (REs) has also been incorporated. The paper demonstrates that the inclusion of plasma cross section evolution in conjunction with REs plays an important role in the formation and development of tokamak startup. The model is benchmarked against experimental results from ADITYA tokamak.

  3. Biopolymeric nanocomposites with enhanced interphases.

    Science.gov (United States)

    Yin, Yi; Hu, Kesong; Grant, Anise M; Zhang, Yuhong; Tsukruk, Vladimir V

    2015-10-06

    Ultrathin and robust nanocomposite membranes were fabricated by incorporating graphene oxide (GO) sheets into a silk fibroin (SF) matrix by a dynamic spin-assisted layer-by-layer assembly (dSA-LbL). We observed that in contrast to traditional SA-LbL reported earlier fast solution removal during dropping of solution on constantly spinning substrates resulted in largely unfolded biomacromolecules with enhanced surface interactions and suppressed nanofibril formation. The resulting laminated nanocomposites possess outstanding mechanical properties, significantly exceeding those previously reported for conventional LbL films with similar composition. The tensile modulus reached extremely high values of 170 GPa, which have never been reported for graphene oxide-based nanocomposites, the ultimate strength was close to 300 MPa, and the toughness was above 3.4 MJ m(-3). The failure modes observed for these membranes suggested the self-reinforcing mechanism of adjacent graphene oxide sheets with strong 2 nm thick silk interphase composed mostly from individual backbones. This interphase reinforcement leads to the effective load transfer between the graphene oxide components in reinforced laminated nanocomposite materials with excellent mechanical strength that surpasses those known today for conventional flexible laminated carbon nanocomposites from graphene oxide and biopolymer components.

  4. Enhanced decision making through neuroscience

    Science.gov (United States)

    Szu, Harold; Jung, TP; Makeig, Scott

    2012-06-01

    We propose to enhance the decision making of pilot, co-pilot teams, over a range of vehicle platforms, with the aid of neuroscience. The goal is to optimize this collaborative decision making interplay in time-critical, stressful situations. We will research and measure human facial expressions, personality typing, and brainwave measurements to help answer questions related to optimum decision-making in group situations. Further, we propose to examine the nature of intuition in this decision making process. The brainwave measurements will be facilitated by a University of California, San Diego (UCSD) developed wireless Electroencephalography (EEG) sensing cap. We propose to measure brainwaves covering the whole head area with an electrode density of N=256, and yet keep within the limiting wireless bandwidth capability of m=32 readouts. This is possible because solving Independent Component Analysis (ICA) and finding the hidden brainwave sources allow us to concentrate selective measurements with an organized sparse source -->s sensing matrix [Φs], rather than the traditional purely random compressive sensing (CS) matrix[Φ].

  5. Carbon-enhanced VRLA batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Enos, David George; Hund, Thomas D.; Shane, Rod (East Penn Manufacturing, Lyon Station, PA)

    2010-10-01

    The addition of certain forms of carbon to the negative plate in valve regulated lead acid (VRLA) batteries has been demonstrated to increase the cycle life of such batteries by an order of magnitude or more under high-rate, partial-state-of-charge operation. Such performance will provide a significant impact, and in some cases it will be an enabling feature for applications including hybrid electric vehicles, utility ancillary regulation services, wind farm energy smoothing, and solar photovoltaic energy smoothing. There is a critical need to understnd how the carbon interacts with the negative plate and achieves the aforementioned benefits at a fundamental level. Such an understanding will not only enable the performance of such batteries to be optimzied, but also to explore the feasibility of applying this technology to other battery chemistries. In partnership with the East Penn Manufacturing, Sandia will investigate the electrochemical function of the carbon and possibly identify improvements to its anti-sulfation properties. Shiomi, et al. (1997) discovered that the addition of carbon to the negative active material (NAM) substantially reduced PbSO{sub 4} accumulation in high rate, partial state of charge (HRPSoC) cycling applications. This improved performance with a minimal cost. Cycling applications that were uneconomical for traditional VRLA batteries are viable for the carbon enhanced VRLA. The overall goal of this work is to quantitatively define the role that carbon plays in the electrochemistry of a VRLA battery.

  6. Coherently Enhanced Wireless Power Transfer

    Science.gov (United States)

    Krasnok, Alex; Baranov, Denis G.; Generalov, Andrey; Li, Sergey; Alù, Andrea

    2018-04-01

    Extraction of electromagnetic energy by an antenna from impinging external radiation is at the basis of wireless communications and wireless power transfer (WPT). The maximum of transferred energy is ensured when the antenna is conjugately matched, i.e., when it is resonant and it has an equal coupling with free space and its load. This condition, however, can be easily affected by changes in the environment, preventing optimal operation of a WPT system. Here, we introduce the concept of coherently enhanced WPT that allows us to bypass this difficulty and achieve dynamic control of power transfer. The approach relies on coherent excitation of the waveguide connected to the antenna load with a backward propagating signal of specific amplitude and phase. This signal creates a suitable interference pattern at the load resulting in a modification of the local wave impedance, which in turn enables conjugate matching and a largely increased amount of extracted energy. We develop a simple theoretical model describing this concept, demonstrate it with full-wave numerical simulations for the canonical example of a dipole antenna, and verify experimentally in both near-field and far-field regimes.

  7. Enhanced Model for Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Rodney J. [Research Applications Corporation, Los Alamos, NM (United States)

    2010-10-12

    Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

  8. Narrowband Compton Scattering Yield Enhancement

    Science.gov (United States)

    Rykovanov, Sergey; Seipt, Daniel; Kharin, Vasily

    2017-10-01

    Compton Scattering (CS) of laser light off high-energy electrons is a well-established source of X- and gamma-rays for applications in medicine, biology, nuclear and material sciences. Main advantage of CS photon sources is the possibility to generate narrow spectra as opposed to a broad continuum obtained when utilizing Bremsstrahlung. However, due to the low cross-section of the linear process, the total photon yield is quite low. The most straightforward way to increase the number of photon-electron beam scattering events is to increase the laser pulse intensity at the interaction point by harder focusing. This leads to an unfortunate consequence. Increase in the laser pulse normalized amplitude a0, leads to additional ponderomotive spectrum broadening of the scattered radiation. The ponderomotive broadening is caused by the v × B force, which slows the electron down near the peak of the laser pulse where the intensity is high, and can be neglected near the wings of the pulse, where the intensity is low. We show that laser pulse chirping, both nonlinear (laser pulse frequency ''following'' the envelope of the pulse) and linear, leads to compensation of the ponderomotive broadening and considerably enhances the yield of the nonlinear Compton sources. Work supported by the Helmholtz Association via Helmholtz Young Investigators Grant (VH-NG-1037).

  9. Enhancing professionalism at GPU nuclear

    International Nuclear Information System (INIS)

    Coe, R.P.; Landy, F.J.

    1991-01-01

    Late in 1988, GPU Nuclear embarked on a major program aimed at enhancing Professionalism at its Oyster Creek and Three Mile Island Nuclear Generating Stations. The program was also to include its Corporate Headquarters in Parsippany, New Jersey. The overall program was to take several directions which included on-site degree programs, a sabbatical leave-type program for personnel to finish college degrees, advanced technical training for licensed staff, career progression for SROs and expanded teamwork and leadership training for control room crews. The largest portion of this initiative was the development and delivery of professionalism training to the nearly two thousand people at both sites. Three primary philosophies guided the development of the program. Employees as Experts: First, GPU Nuclear employees were considered to be the most valuable source of information for designing a Professionalism program because it is these individuals who are sensitive to the issues encountered in the workplace. Realism: The second philosophy guiding this effort was that the program must be grounded in real life challenges that employees face and must address. Active Learning: The third guiding philosophy was that, in order to have any real impact on the way employees think about professionalism, the program must utilize active rather than passive learning techniques

  10. Dural enhancement with primary calvarial lesions.

    Science.gov (United States)

    Arana, E; Martí-Bonmatí, L; Ricart, V; Pérez-Ebrí, M

    2004-11-01

    The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

  11. Electroluminescence Efficiency Enhancement using Metal Nanoparticles

    National Research Council Canada - National Science Library

    Soref, Richard A; Khurgin, J. B; Sun, G

    2008-01-01

    We apply the "effective mode volume" theory to evaluate enhancement of the electroluminescence efficiency of semiconductor emitters placed in the vicinity of isolated metal nanoparticles and their arrays...

  12. Patterns of uterine enhancement with helical CT

    International Nuclear Information System (INIS)

    Kaur, H.; Loyer, E.M.; Charnsangavej, C.; Minami, M.

    1998-01-01

    Objective: The purpose of this study was to evaluate the enhancement characteristics of the normal uterine body and cervix using dynamic contrast-enhanced helical CT. Methods: Thirty-eight women scheduled for pelvic CT for non-gynecologic malignancies underwent dynamic contrast-enhanced helical CT of the pelvis. Data acquisition was during the arterial phase (30-45 s after the start of injection), the parenchymal phase (90-120 s after the start of injection), and delayed phase (3-9 min after the start of injection). The images were evaluated by four radiologists for the pattern of myometrial and cervical enhancement. Correlation was made with the age and menstrual status of the patients. Results: In the uterine body, three types of enhancement were observed. Type 1 enhancement, seen in 16 patients (42%), was characterized by the visualization of a subendometrial zone of enhancement, 30-120 s after the start of injection. Eight of these patients also showed an enhancing zone in the outer myometrium. Both zones were transitory, and in all cases, the uterus became homogeneous in the delayed phase. This pattern was seen predominantly in premenopausal women with a mean age of 34 years. Type 2 enhancement, seen in 17 cases (45%), was defined by the absence of subendometrial enhancement in the early phase. Enhancement was either diffuse from the outset or originated in the outer myometrium. This pattern was seen nearly equally in premenopausal and postmenopausal women with a mean age of 40 years. Type 3 enhancement was seen in five postmenopausal patients (13%) with a mean age of 53 years and was characterized by faint diffuse enhancement. In the cervix, a zonal pattern of enhancement defining inner and outer stroma was seen in 23 patients (61%). Fifteen patients were premenopausal and eight were postmenopausal. Conclusion: In this study, we have shown a transitory zonal distribution of the contrast in the myometrium and cervix using dynamic contrast-enhanced helical CT

  13. Enhancer-derived RNA: A Primer.

    Science.gov (United States)

    Liu, Feng

    2017-06-01

    Enhancer-derived RNAs (eRNAs) are a group of RNAs transcribed by RNA polymerase II from the domain of transcription enhancers, a major type of cis-regulatory elements in the genome. The correlation between eRNA production and enhancer activity has stimulated studies on the potential role of eRNAs in transcriptional regulation. Additionally, eRNA has also served as a marker for global identification of enhancers. Here I review the brief history and fascinating properties of eRNAs. Copyright © 2017 The Author. Production and hosting by Elsevier B.V. All rights reserved.

  14. Enhancer-derived RNA: A Primer

    Directory of Open Access Journals (Sweden)

    Feng Liu

    2017-06-01

    Full Text Available Enhancer-derived RNAs (eRNAs are a group of RNAs transcribed by RNA polymerase II from the domain of transcription enhancers, a major type of cis-regulatory elements in the genome. The correlation between eRNA production and enhancer activity has stimulated studies on the potential role of eRNAs in transcriptional regulation. Additionally, eRNA has also served as a marker for global identification of enhancers. Here I review the brief history and fascinating properties of eRNAs.

  15. Identification of a novel ga-related bush mutant in pumpkin (cucurbita moschata duchesne)

    International Nuclear Information System (INIS)

    Wu, T.; Cao, J.

    2015-01-01

    Pumpkin (Cucurbita moschata Duchesne) bush mutant plants were characterized by short stems. The sensitivity of pumpkin bush mutant plants to exogenous hormones was identified in this study. Results revealed that internode elongation of bush mutant plants could respond to gibberellins (GA4+7 and GA3), but not to indole acetic acid (IAA) and brassinosteroids (BR); by contrast, the mutant phenotype of bush mutant plants could not be fully rescued by GA4+7 and GA3. The internode of bush mutant plants yielded a lower KS expression level than that of vine plants. Therefore, pumpkin bush mutant plants were designated as GA-related mutant plants eliciting a partial response to GAs; the action of IAA and BR might not be involved in the internode growth of pumpkin bush mutant plants, specifically Cucurbita moschata Duch. (author)

  16. The Synergistic Priming Effect of Exogenous Salicylic Acid and H2O2 on Chilling Tolerance Enhancement during Maize (Zea mays L.) Seed Germination.

    Science.gov (United States)

    Li, Zhan; Xu, Jungui; Gao, Yue; Wang, Chun; Guo, Genyuan; Luo, Ying; Huang, Yutao; Hu, Weimin; Sheteiwy, Mohamed S; Guan, Yajing; Hu, Jin

    2017-01-01

    Chilling stress is an important constraint for maize seedling establishment in the field. To examine the role of salicylic acid (SA) and hydrogen peroxide (H 2 O 2 ) in response to chilling stress, we investigated the effects of seed priming with SA, H 2 O 2 , and SA+H 2 O 2 combination on maize resistance under chilling stress (13°C). Priming with SA, H 2 O 2 , and especially SA+H 2 O 2 shortened seed germination time and enhanced seed vigor and seedling growth as compared with hydropriming and non-priming treatments under low temperature. Meanwhile, SA+H 2 O 2 priming notably increased the endogenous H 2 O 2 and SA content, antioxidant enzymes activities and their corresponding genes ZmPAL, ZmSOD4, ZmAPX2, ZmCAT2 , and ZmGR expression levels. The α-amylase activity was enhanced to mobilize starch to supply metabolites such as soluble sugar and energy for seed germination under chilling stress. In addition, the SA+H 2 O 2 combination positively up-regulated expressions of gibberellic acid (GA) biosynthesis genes ZmGA20ox1 and ZmGA3ox2 , and down-regulated GA catabolism gene ZmGA2ox1 expression; while it promoted GA signaling transduction genes expressions of ZmGID1 and ZmGID2 and decreased the level of seed germination inhibitor gene ZmRGL2 . The abscisic acid (ABA) catabolism gene ZmCYP707A2 and the expressions of ZmCPK11 and ZmSnRK2.1 encoding response receptors in ABA signaling pathway were all up-regulated. These results strongly suggested that priming with SA and H 2 O 2 synergistically promoted hormones metabolism and signal transduction, and enhanced energy supply and antioxidant enzymes activities under chilling stress, which were closely relevant with chilling injury alleviation and chilling-tolerance improvement in maize seed. Highlights: Seed germination and seedling growth were significantly improved under chilling stress by priming with SA+H 2 O 2 combination, which was closely relevant with the change of reactive oxygen species, metabolites and

  17. The Synergistic Priming Effect of Exogenous Salicylic Acid and H2O2 on Chilling Tolerance Enhancement during Maize (Zea mays L.) Seed Germination

    Science.gov (United States)

    Li, Zhan; Xu, Jungui; Gao, Yue; Wang, Chun; Guo, Genyuan; Luo, Ying; Huang, Yutao; Hu, Weimin; Sheteiwy, Mohamed S.; Guan, Yajing; Hu, Jin

    2017-01-01

    Chilling stress is an important constraint for maize seedling establishment in the field. To examine the role of salicylic acid (SA) and hydrogen peroxide (H2O2) in response to chilling stress, we investigated the effects of seed priming with SA, H2O2, and SA+H2O2 combination on maize resistance under chilling stress (13°C). Priming with SA, H2O2, and especially SA+H2O2 shortened seed germination time and enhanced seed vigor and seedling growth as compared with hydropriming and non-priming treatments under low temperature. Meanwhile, SA+H2O2 priming notably increased the endogenous H2O2 and SA content, antioxidant enzymes activities and their corresponding genes ZmPAL, ZmSOD4, ZmAPX2, ZmCAT2, and ZmGR expression levels. The α-amylase activity was enhanced to mobilize starch to supply metabolites such as soluble sugar and energy for seed germination under chilling stress. In addition, the SA+H2O2 combination positively up-regulated expressions of gibberellic acid (GA) biosynthesis genes ZmGA20ox1 and ZmGA3ox2, and down-regulated GA catabolism gene ZmGA2ox1 expression; while it promoted GA signaling transduction genes expressions of ZmGID1 and ZmGID2 and decreased the level of seed germination inhibitor gene ZmRGL2. The abscisic acid (ABA) catabolism gene ZmCYP707A2 and the expressions of ZmCPK11 and ZmSnRK2.1 encoding response receptors in ABA signaling pathway were all up-regulated. These results strongly suggested that priming with SA and H2O2 synergistically promoted hormones metabolism and signal transduction, and enhanced energy supply and antioxidant enzymes activities under chilling stress, which were closely relevant with chilling injury alleviation and chilling-tolerance improvement in maize seed. Highlights:Seed germination and seedling growth were significantly improved under chilling stress by priming with SA+H2O2 combination, which was closely relevant with the change of reactive oxygen species, metabolites and energy supply, hormones metabolism and

  18. Robotically enhanced rubber hand illusion.

    Science.gov (United States)

    Arata, Jumpei; Hattori, Masashi; Ichikawa, Shohei; Sakaguchi, Masamichi

    2014-01-01

    The rubber hand illusion is a well-known multisensory illusion. In brief, watching a rubber hand being stroked by a paintbrush while one's own unseen hand is synchronously stroked causes the rubber hand to be attributed to one's own body and to "feel like it's my hand." The rubber hand illusion is thought to be triggered by the synchronized tactile stimulation of both the subject's hand and the fake hand. To extend the conventional rubber hand illusion, we introduce robotic technology in the form of a master-slave telemanipulator. The developed one degree-of-freedom master-slave system consists of an exoskeleton master equipped with an optical encoder that is worn on the subject's index finger and a motor-actuated index finger on the rubber hand, which allows the subject to perform unilateral telemanipulation. The moving rubber hand illusion has been studied by several researchers in the past with mechanically connected rigs between the subject's body and the fake limb. The robotic instruments let us investigate the moving rubber hand illusion with less constraints, thus behaving closer to the classic rubber hand illusion. In addition, the temporal delay between the body and the fake limb can be precisely manipulated. The experimental results revealed that the robotic instruments significantly enhance the rubber hand illusion. The time delay is significantly correlated with the effect of the multisensory illusion, and the effect significantly decreased at time delays over 100 ms. These findings can potentially contribute to the investigations of neural mechanisms in the field of neuroscience and of master-slave systems in the field of robotics.

  19. Protocolized hyperventilation enhances electroconvulsive therapy.

    Science.gov (United States)

    de Arriba-Arnau, Aida; Dalmau, Antonia; Soria, Virginia; Salvat-Pujol, Neus; Ribes, Carmina; Sánchez-Allueva, Ana; Menchón, José Manuel; Urretavizcaya, Mikel

    2017-08-01

    Hyperventilation is recommended in electroconvulsive therapy (ECT) to enhance seizures and to increase patients' safety. However, more evidence is needed regarding its effects and the optimum method of application. This prospective study involving 21 subjects compared two procedures, protocolized hyperventilation (PHV) and hyperventilation as usual (HVau), applied to the same patient in two consecutive sessions. Transcutaneous partial pressure of carbon dioxide (TcPCO 2 ) was measured throughout all sessions. Ventilation parameters, hemodynamic measures, seizure characteristics, and side effects were also explored. PHV resulted in lower TcPCO 2 after hyperventilation (p=.008) and over the whole session (p=.035). The lowest TcPCO 2 was achieved after voluntary hyperventilation. Changes in TcPCO 2 from baseline showed differences between HVau and PHV at each session time-point (all p<.05). Between- and within-subjects factors were statistically significant in a general linear model. Seizure duration was greater in PHV sessions (p=.028), without differences in other seizure quality parameters or adverse effects. Correlations were found between hypocapnia induction and seizure quality indexes. Secondary outcomes could be underpowered. PHV produces hypocapnia before the stimulus, modifies patients' TcPCO 2 values throughout the ECT session and lengthens seizure duration. Voluntary hyperventilation is the most important part of the PHV procedure with respect to achieving hypocapnia. A specific ventilation approach, CO 2 quantification and monitoring may be advisable in ECT. PHV is easy to apply in daily clinical practice and does not imply added costs. Ventilation management has promising effects in terms of optimizing ECT technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Oscillatory Reinstatement Enhances Declarative Memory.

    Science.gov (United States)

    Javadi, Amir-Homayoun; Glen, James C; Halkiopoulos, Sara; Schulz, Mei; Spiers, Hugo J

    2017-10-11

    Declarative memory recall is thought to involve the reinstatement of neural activity patterns that occurred previously during encoding. Consistent with this view, greater similarity between patterns of activity recorded during encoding and retrieval has been found to predict better memory performance in a number of studies. Recent models have argued that neural oscillations may be crucial to reinstatement for successful memory retrieval. However, to date, no causal evidence has been provided to support this theory, nor has the impact of oscillatory electrical brain stimulation during encoding and retrieval been assessed. To explore this we used transcranial alternating current stimulation over the left dorsolateral prefrontal cortex of human participants [ n = 70, 45 females; age mean (SD) = 22.12 (2.16)] during a declarative memory task. Participants received either the same frequency during encoding and retrieval (60-60 or 90-90 Hz) or different frequencies (60-90 or 90-60 Hz). When frequencies matched there was a significant memory improvement (at both 60 and 90 Hz) relative to sham stimulation. No improvement occurred when frequencies mismatched. Our results provide support for the role of oscillatory reinstatement in memory retrieval. SIGNIFICANCE STATEMENT Recent neurobiological models of memory have argued that large-scale neural oscillations are reinstated to support successful memory retrieval. Here we used transcranial alternating current stimulation (tACS) to test these models. tACS has recently been shown to induce neural oscillations at the frequency stimulated. We stimulated over the left dorsolateral prefrontal cortex during a declarative memory task involving learning a set of words. We found that tACS applied at the same frequency during encoding and retrieval enhances memory. We also find no difference between the two applied frequencies. Thus our results are consistent with the proposal that reinstatement of neural oscillations during retrieval