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Peter Beyer - One of the best experts on this subject based on the ideXlab platform.
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Summary
2014Co-Authors: Peter Burkhardt K. T, Gregory A. Armstrong, Peter Beyer, Johannes Von Lintig, Joachim Wqnn, Andreas Klbti, Ingo PotrykusAbstract:Transgenic rice (Oryza sativa) endosperm expressing daffodil (Narcissus pseudoNarcissus) phytoene synthase accumulates phytoene, a key intermediate of provitamin A biosynthesi
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Biosynthesis of monoterpene hydrocarbons by isolated chromoplasts from daffodil flowers.
FEBS Journal, 2005Co-Authors: U. Mettal, W. Boland, Peter Beyer, Hans KleinigAbstract:Incubation studies using [1-14C]isopentenyl diphosphate and [1-2H2]isopentenyl diphosphate as substrates revealed that isolated chromoplasts from flowers of Narcissus pseudoNarcissus L. are able to synthesize monoterpene hydrocarbons and linalool in high yields. The enzymes involved are soluble in the chromoplast stroma. It is hypothesized that in the plant cell plastids are the site of monoterpene biosynthesis, whereas the formation of sesquiterpenes may be restricted to the cytoplasm/endoplasmic reticulum.
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Chemiosmotic ATP synthesis in photosynthetically inactive chromoplasts from Narcissus pseudoNarcissus L. linked to a redox pathway potentially also involved in carotene desaturation.
Planta, 2002Co-Authors: Lucia Morstadt, Hans Kleinig, Peter Gräber, Luca De Pascalis, Volker Speth, Peter BeyerAbstract:Mature chromoplasts from daffodil (Narcissus pseudoNarcissus) flowers, although devoid of thylakoid structures, contain immunologically detectable α-subunits of ATP-synthase (H+-transporting ATP phosphohydrolase; EC 3.6.3.14). To show the presence of the entire functional protein complex, chromoplast membrane proteins were solubilized and reconstituted in phosphatidylcholine liposomes. The membranes were energized by an acid-base transition in the presence of a K+/valinomycin diffusion potential, and the initial rate of ATP synthesis was measured with a luciferin/luciferase assay. In addition, by demonstrating NADPH-dependent ATP synthesis, we show that an NAD(P)H-dependent respiratory redox pathway in chromoplasts, previously identified as an important constituent of the carotene desaturation system, proceeds concomitant with membrane energization.
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cpta modulates levels of carotenogenic proteins and their mrnas and affects carotenoid and aba content as well as chromoplast structure in Narcissus pseudoNarcissus flowers
Plant Biology, 1999Co-Authors: Salim Albabili, Hans Kleinig, W Hartung, Peter BeyerAbstract:: To investigate mechanisms leading to enhanced carotenoid formation, daffodil (Narcissus pseudoNarcissus) flowers were treated with the lycopene cyclase (LYC) inhibitor CPTA. Under these conditions, chromoplasts underwent strong morphological changes and the lycopene accumulated was found sequestered in crystals. During this process the total carotenoid content increased about 2-fold. This increase was accompanied by an upregulation of the transcript levels of phytoene synthase (PSY), phytoene desaturase (PDS) and lycopene cyclase (LYC). In contrast, η-carotene desaturase (ZDS) was not a target for CPTA-induced upregulation, although its product lycopene was accumulated. At the protein level, CPTA induction of carotenogenic enzymes was also observed, again with the exception of ZDS. Lycopene accumulation, caused by CPTA treatment, was also accompanied by a decrease of β-carotene derivatives, especially zeaxanthin. Our data suggest that carotenoid biosynthesis may undergo an end-product regulation via an effector probably originating from a β-carotene derivative. Increased concentrations of abscisic acid (ABA) measured after CPTA treatment may be involved in this regulatory phenomenon, pointing to the presence of an additional xanthophyll-independent source of this phytohormone.
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Transgenic rice (Oryza sativa) endosperm expressing daffodil (Narcissus pseudoNarcissus) phytoene synthase accumulates phytoene, a key intermediate of provitamin A biosynthesis
Plant Journal, 1997Co-Authors: P. K. Burkhardt, J. Wünn, Andreas Klöti, Gregory A. Armstrong, Michael Schledz, Peter Beyer, Johannes Von Lintig, Ingo PotrykusAbstract:Rice (Oryza sativa L.), the major food staple for more than two billion people, contains neither β-carotene (provitamin A) nor C40 carotenoid precursors thereof in its endosperm. To improve the nutritional value of rice, genetic engineering was chosen as a means to introduce the ability to make β-carotene into rice endosperm tissue. Investigation of the biochemical properties of immature rice endosperm using [14C]-labelled substrates revealed the presence of geranyl geranyl diphosphate, the C20 general isoprenoid precursor necessary for C40 carotenoid biosynthesis. Phytoene synthase, which condenses two molecules of geranyl geranyl diphosphate, is the first of four specific enzymes necessary for β-carotene biosynthesis in plants. Therefore, the Japonica rice model variety Taipei 309 was transformed by microprojectile bombardment with a cDNA coding for phytoene synthase from daffodil (Narcissus pseudoNarcissus) under the control of either a constitutive or an endosperm-specific promoter. In transgenic rice plants, the daffodil enzyme is active, as measured by the in vivo accumulation of phytoene in rice endosperm. Thus, it is demonstrated for the first time that it is in principle possible to engineer a critical step in provitamin A biosynthesis in a non-photosynthetic, carotenoid-lacking plant tissue. These results have important implications for longterm prospects of overcoming worldwide vitamin A deficiency.
Richard H. Ellis - One of the best experts on this subject based on the ideXlab platform.
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ecophysiology of seed dormancy and the control of germination in early spring flowering galanthus nivalis and Narcissus pseudoNarcissus amaryllidaceae
Botanical Journal of the Linnean Society, 2015Co-Authors: Rosemary J. Newton, Fiona R. Hay, Richard H. EllisAbstract:Seed dormancy induction and alleviation in the winter-flowering, moist temperate woodland species Galanthus nivalis and Narcissus pseudoNarcissus are complex and poorly understood. Temperature, light and desiccation were investigated to elucidate their role in the germination ecophysiology of these species. The effect of different seasonal temperatures, seasonal durations, temperature fluctuations, the presence of light during different seasons and intermittent drying (during the summer period) over several ‘years’ on seed germination was investigated with outdoor and laboratory experiments. Warm summer-like temperatures (20 °C) were necessary for germination at subsequent cooler autumn-like temperatures (greatest at 15 °C in G. nivalis and 10 °C in N. pseudoNarcissus). As the warm temperature duration increased, so did germination at subsequent cooler temperatures; further germination occurred in subsequent ‘years’ at cooler temperatures following a second, and also third, warm period. Germination was significantly greater in darkness, particularly in G. nivalis. Dormancy increased with seed maturation period in G. nivalis, because seeds extracted from green capsules germinated more readily than those from yellow capsules. Desiccation increased dormancy in an increasing proportion of N. pseudoNarcissus seeds the later they were dried in ‘summer’. Seed viability was only slightly reduced by desiccation in N. pseudoNarcissus, but was poor and variable in G. nivalis. Shoot formation occurred both at the temperature at which germination was greatest and also if 5 °C cooler. In summary, continuous hydration of seeds of both species during warm summer-like temperatures results in the gradual release of seed dormancy; thereafter, darkness and cooler temperatures promote germination. Cold temperatures, increased seed maturity (G. nivalis) and desiccation (N. pseudoNarcissus) increase dormancy, and light inhibits germination. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177, 246–262.
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Seed development and maturation in early spring-flowering Galanthus nivalis and Narcissus pseudoNarcissus continues post-shedding with little evidence of maturation in planta.
Annals of Botany, 2013Co-Authors: Rosemary J. Newton, Fiona R. Hay, Richard H. EllisAbstract:Background and Aims Seeds of the moist temperate woodland species Galanthus nivalis and Narcissus pseudoNarcissus, dispersed during spring or early summer, germinated poorly in laboratory tests. Seed development and maturation were studied to better understand the progression from developmental to germinable mode in order to improve seed collection and germination practices in these and similar species.
Rosemary J. Newton - One of the best experts on this subject based on the ideXlab platform.
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ecophysiology of seed dormancy and the control of germination in early spring flowering galanthus nivalis and Narcissus pseudoNarcissus amaryllidaceae
Botanical Journal of the Linnean Society, 2015Co-Authors: Rosemary J. Newton, Fiona R. Hay, Richard H. EllisAbstract:Seed dormancy induction and alleviation in the winter-flowering, moist temperate woodland species Galanthus nivalis and Narcissus pseudoNarcissus are complex and poorly understood. Temperature, light and desiccation were investigated to elucidate their role in the germination ecophysiology of these species. The effect of different seasonal temperatures, seasonal durations, temperature fluctuations, the presence of light during different seasons and intermittent drying (during the summer period) over several ‘years’ on seed germination was investigated with outdoor and laboratory experiments. Warm summer-like temperatures (20 °C) were necessary for germination at subsequent cooler autumn-like temperatures (greatest at 15 °C in G. nivalis and 10 °C in N. pseudoNarcissus). As the warm temperature duration increased, so did germination at subsequent cooler temperatures; further germination occurred in subsequent ‘years’ at cooler temperatures following a second, and also third, warm period. Germination was significantly greater in darkness, particularly in G. nivalis. Dormancy increased with seed maturation period in G. nivalis, because seeds extracted from green capsules germinated more readily than those from yellow capsules. Desiccation increased dormancy in an increasing proportion of N. pseudoNarcissus seeds the later they were dried in ‘summer’. Seed viability was only slightly reduced by desiccation in N. pseudoNarcissus, but was poor and variable in G. nivalis. Shoot formation occurred both at the temperature at which germination was greatest and also if 5 °C cooler. In summary, continuous hydration of seeds of both species during warm summer-like temperatures results in the gradual release of seed dormancy; thereafter, darkness and cooler temperatures promote germination. Cold temperatures, increased seed maturity (G. nivalis) and desiccation (N. pseudoNarcissus) increase dormancy, and light inhibits germination. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177, 246–262.
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Seed development and maturation in early spring-flowering Galanthus nivalis and Narcissus pseudoNarcissus continues post-shedding with little evidence of maturation in planta.
Annals of Botany, 2013Co-Authors: Rosemary J. Newton, Fiona R. Hay, Richard H. EllisAbstract:Background and Aims Seeds of the moist temperate woodland species Galanthus nivalis and Narcissus pseudoNarcissus, dispersed during spring or early summer, germinated poorly in laboratory tests. Seed development and maturation were studied to better understand the progression from developmental to germinable mode in order to improve seed collection and germination practices in these and similar species.
Donald A. Hunter - One of the best experts on this subject based on the ideXlab platform.
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role of ethylene in perianth senescence of daffodil Narcissus pseudoNarcissus l dutch master
Postharvest Biology and Technology, 2004Co-Authors: Donald A. Hunter, Michael S. ReidAbstract:Abstract Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers senesced prematurely when exposed to 1 μl l−1 ethylene. The hormone caused watersoaking of the perianth, a symptom not seen in perianths of flowers held in air. Ethylene also enhanced the expression of senescence-associated transcripts in the daffodil tepals. The ethylene-enhanced transcript accumulation and the ethylene-accelerated senescence were prevented by pretreating the flowers with 500 nl l−1 1-methylcyclopropene (1-MCP) for 6 h at 20 °C. Repeated 1-MCP treatments provided only a modest extension in longevity of attached flowers held in air and had no noticeable effect on the life of detached flowers held in water. The unpollinated flowers produced negligible amounts of ethylene (
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Role of ethylene in perianth senescence of daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’)
Postharvest Biology and Technology, 2004Co-Authors: Donald A. Hunter, Michael S. ReidAbstract:Abstract Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers senesced prematurely when exposed to 1 μl l−1 ethylene. The hormone caused watersoaking of the perianth, a symptom not seen in perianths of flowers held in air. Ethylene also enhanced the expression of senescence-associated transcripts in the daffodil tepals. The ethylene-enhanced transcript accumulation and the ethylene-accelerated senescence were prevented by pretreating the flowers with 500 nl l−1 1-methylcyclopropene (1-MCP) for 6 h at 20 °C. Repeated 1-MCP treatments provided only a modest extension in longevity of attached flowers held in air and had no noticeable effect on the life of detached flowers held in water. The unpollinated flowers produced negligible amounts of ethylene (
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Role of abscisic acid in perianth senescence of daffodil (Narcissus pseudoNarcissus"Dutch Master").
Physiologia plantarum, 2004Co-Authors: Donald A. Hunter, Antonio Ferrante, Paolo Vernieri, Michael S ReidAbstract:Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’)flowers detached at the base of their ovaries and held withtheir cut ends in 10–100mM abscisic acid (ABA) senescedprematurely. Symptoms of the ABA treatment includedwater-soaking of the tepals and early collapse of the corona.No water-soaking was seen in tepals of flowers held in water.Instead, the tepals of these flowers dried. The ABA contentincreased in tepals of the potted flowers as they senesced. Therise in tepal ABA content coincided with the appearance ofvisual signs of senescence. When the flowers were cut andplaced in water, a treatment that accelerated their senescence,the increase in ABA occurred earlier. Exogenously appliedABA enhanced the premature accumulation of senescence-associated transcripts in the tepals. Their ABA-mediatedinduction was not prevented when the flowers were pre-treatedwith 1-methylcyclopropene, an inhibitor of ethylene action,indicating that ABA induced the transcripts independentlyof ethylene. The transcripts accumulated in opened controlflowers before the rise in endogenous ABA. Attempts toextend floral longevity by using putative inhibitors of ABAbiosynthesis [tungstate, fluridone (applied as Sonar
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identification of genes associated with perianth senescence in daffodil Narcissus pseudoNarcissus l dutch master
Plant Science, 2002Co-Authors: Donald A. Hunter, Brian Cameron Steele, Michael S ReidAbstract:We used a PCR-based subtractive procedure to isolate genes that increased in abundance in the perianth of incipiently senescent daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers. Using RNA gel blot analysis we confirmed that 18 of the transcripts were senescence-associated. A number of these have homologs in previously-studied senescing floral and leaf tissue systems (cysteine proteases, serine proteases, endonuclease, vacuole processing enzyme). Some showed homology to genes encoding proteins with transport functions (auxin efflux carrier protein, low affinity nitrate transporter), others to enzymes that may have a role in cellular signaling (RSH-like protein). A surprising number of the isolated genes either showed no homology with previously-reported sequences or were sequences with no known function. A strong association of some of the transcripts with senescence was also indicated by their enhanced accumulation in the perianth of detached daffodil flowers, which senesce earlier than attached flowers. # 2002 Elsevier Science Ireland Ltd. All rights reserved.
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Identification of genes associated with perianth senescence in Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’)
Plant Science, 2002Co-Authors: Donald A. Hunter, Brian Cameron Steele, Michael S. ReidAbstract:We used a PCR-based subtractive procedure to isolate genes that increased in abundance in the perianth of incipiently senescent daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers. Using RNA gel blot analysis we confirmed that 18 of the transcripts were senescence-associated. A number of these have homologs in previously-studied senescing floral and leaf tissue systems (cysteine proteases, serine proteases, endonuclease, vacuole processing enzyme). Some showed homology to genes encoding proteins with transport functions (auxin efflux carrier protein, low affinity nitrate transporter), others to enzymes that may have a role in cellular signaling (RSH-like protein). A surprising number of the isolated genes either showed no homology with previously-reported sequences or were sequences with no known function. A strong association of some of the transcripts with senescence was also indicated by their enhanced accumulation in the perianth of detached daffodil flowers, which senesce earlier than attached flowers. # 2002 Elsevier Science Ireland Ltd. All rights reserved.
Michael S. Reid - One of the best experts on this subject based on the ideXlab platform.
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role of ethylene in perianth senescence of daffodil Narcissus pseudoNarcissus l dutch master
Postharvest Biology and Technology, 2004Co-Authors: Donald A. Hunter, Michael S. ReidAbstract:Abstract Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers senesced prematurely when exposed to 1 μl l−1 ethylene. The hormone caused watersoaking of the perianth, a symptom not seen in perianths of flowers held in air. Ethylene also enhanced the expression of senescence-associated transcripts in the daffodil tepals. The ethylene-enhanced transcript accumulation and the ethylene-accelerated senescence were prevented by pretreating the flowers with 500 nl l−1 1-methylcyclopropene (1-MCP) for 6 h at 20 °C. Repeated 1-MCP treatments provided only a modest extension in longevity of attached flowers held in air and had no noticeable effect on the life of detached flowers held in water. The unpollinated flowers produced negligible amounts of ethylene (
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Role of ethylene in perianth senescence of daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’)
Postharvest Biology and Technology, 2004Co-Authors: Donald A. Hunter, Michael S. ReidAbstract:Abstract Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers senesced prematurely when exposed to 1 μl l−1 ethylene. The hormone caused watersoaking of the perianth, a symptom not seen in perianths of flowers held in air. Ethylene also enhanced the expression of senescence-associated transcripts in the daffodil tepals. The ethylene-enhanced transcript accumulation and the ethylene-accelerated senescence were prevented by pretreating the flowers with 500 nl l−1 1-methylcyclopropene (1-MCP) for 6 h at 20 °C. Repeated 1-MCP treatments provided only a modest extension in longevity of attached flowers held in air and had no noticeable effect on the life of detached flowers held in water. The unpollinated flowers produced negligible amounts of ethylene (
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Identification of genes associated with perianth senescence in Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’)
2002Co-Authors: Donald Alex, Er Hunter, Brian Cameron Steele, Michael S. ReidAbstract:We used a PCR-based subtractive procedure to isolate genes that increased in abundance in the perianth of incipiently senescent daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers. Using RNA gel blot analysis we confirmed that 18 of the transcripts were senescence-associated. A number of these have homologs in previously-studied senescing floral and leaf tissue systems (cysteine proteases, serine proteases, endonuclease, vacuole processing enzyme). Some showed homology to genes encoding proteins with transport functions (auxin efflux carrier protein, low affinity nitrate transporter), others to enzymes that may have a role in cellular signaling (RSH-like protein). A surprising number of the isolated genes either showed no homology with previously-reported sequences or were sequences with no known function. A strong association of some of the transcripts with senescence was also indicated by their enhanced accumulation in the perianth of detached daffodil flowers, which senesce earlier than attache
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Identification of genes associated with perianth senescence in Daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’)
Plant Science, 2002Co-Authors: Donald A. Hunter, Brian Cameron Steele, Michael S. ReidAbstract:We used a PCR-based subtractive procedure to isolate genes that increased in abundance in the perianth of incipiently senescent daffodil (Narcissus pseudoNarcissus L. ‘Dutch Master’) flowers. Using RNA gel blot analysis we confirmed that 18 of the transcripts were senescence-associated. A number of these have homologs in previously-studied senescing floral and leaf tissue systems (cysteine proteases, serine proteases, endonuclease, vacuole processing enzyme). Some showed homology to genes encoding proteins with transport functions (auxin efflux carrier protein, low affinity nitrate transporter), others to enzymes that may have a role in cellular signaling (RSH-like protein). A surprising number of the isolated genes either showed no homology with previously-reported sequences or were sequences with no known function. A strong association of some of the transcripts with senescence was also indicated by their enhanced accumulation in the perianth of detached daffodil flowers, which senesce earlier than attached flowers. # 2002 Elsevier Science Ireland Ltd. All rights reserved.
