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Dag-ragnar Blystad - One of the best experts on this subject based on the ideXlab platform.
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Overexpression of the AtSHI gene in Poinsettia, Euphorbia pulcherrima, results in compact plants.
PloS one, 2013Co-Authors: M. Ashraful Islam, Sissel Haugslien, Dag-ragnar Blystad, Henrik Lütken, Sissel Torre, Jakub Rolcik, Søren K. Rasmussen, Jorunn E. Olsen, Jihong Liu ClarkeAbstract:Euphorbia pulcherrima, Poinsettia, is a non-food and non-feed vegetatively propagated ornamental plant. Appropriate plant height is one of the most important traits in Poinsettia production and is commonly achieved by application of chemical growth retardants. To produce compact Poinsettia plants with desirable height and reduce the utilization of growth retardants, the Arabidopsis SHORT INTERNODE (AtSHI) gene controlled by the cauliflower mosaic virus 35S promoter was introduced into Poinsettia by Agrobacterium-mediated transformation. Three independent transgenic lines were produced and stable integration of transgene was verified by PCR and Southern blot analysis. Reduced plant height (21–52%) and internode lengths (31–49%) were obtained in the transgenic lines compared to control plants. This correlates positively with the AtSHI transcript levels, with the highest levels in the most dwarfed transgenic line (TL1). The indole-3-acetic acid (IAA) content appeared lower (11–31% reduction) in the transgenic lines compared to the wild type (WT) controls, with the lowest level (31% reduction) in TL1. Total internode numbers, bract numbers and bract area were significantly reduced in all transgenic lines in comparison with the WT controls. Only TL1 showed significantly lower plant diameter, total leaf area and total dry weight, whereas none of the AtSHI expressing lines showed altered timing of flower initiation, cyathia abscission or bract necrosis. This study demonstrated that introduction of the AtSHI gene into Poinsettia by genetic engineering can be an effective approach in controlling plant height without negatively affecting flowering time. This can help to reduce or avoid the use of toxic growth retardants of environmental and human health concern. This is the first report that AtSHI gene was overexpressed in Poinsettia and transgenic Poinsettia plants with compact growth were produced.
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Production of transgenic Poinsettia with resistance against Poinsettia mosaic virus (PNMV) using Agrobacterium-mediated transformation
Acta Horticulturae, 2011Co-Authors: Jihong Liu Clarke, Carl Spetz, Sissel Haugslien, Merete W. Dees, Roar Moe, Dag-ragnar BlystadAbstract:Genetic engineering plays a significant role for the improvement of ornamental crops. Using an Agrobacterium-mediated transformation approach, we have produced transgenic Poinsettia conferring resistance against Poinsettia mosaic virus (PnMV). A. tumefaciens harbouring three hairpin (hp) RNA gene constructs to generate silencing-based resistance to PnMV was introduced into internode stem explants of Poinsettia cultivar Millenium. Stable integration of transgenes into the Poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISA) revealed that resistance to mechanical inoculation of PnMV was found among the transgenic Poinsettia lines, whereas the controls were susceptible. Grafting technique was used to re-introduce the free branching factor, phytoplasma, back to the selected desirable transgenic Poinsettia lines. Subsequently, fresh cuttings derived from these lines with phytoplasma and branches were further investigated for the stability of PnMV resistance and their morphological performance compared with non-transformed controls. Currently, these lines are undergoing evaluation at the grower's facility for future commercialization.
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Symptomless infectious cDNA clone of a Norwegian isolate of Poinsettia mosaic virus
Archives of Virology, 2008Co-Authors: Carl Spetz, Roar Moe, Dag-ragnar BlystadAbstract:An infectious cDNA clone of a Norwegian isolate of Poinsettia mosaic virus (PnMV) was generated. It consisted of 6,098 nucleotides and encoded a polyprotein of 219.5 kDa. Sequence comparisons indicated that this isolate shared 98.6% (nucleotide) and 97.1% (amino acid) identity with the previously sequenced isolate from Germany. RNA transcripts derived from this cDNA were infectious in Nicotiana benthamiana . However, plants did not present typical PnMV symptoms. Furthermore, RNA transcripts from this cDNA clone were not infectious in Poinsettia. Serial propagation of this cDNA clone in N. benthamiana plants restored symptom induction in this host but did not re-establish infectivity in Poinsettia.
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Agrobacterium tumefaciens-mediated transformation of Poinsettia, Euphorbia pulcherrima, with virus-derived hairpin RNA constructs confers resistance to Poinsettia mosaic virus
Plant cell reports, 2008Co-Authors: Jihong Liu Clarke, Carl Spetz, Sissel Haugslien, Shaochen Xing, Merete W. Dees, Roar Moe, Dag-ragnar BlystadAbstract:Agrobacterium-mediated transformation for Poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch) is reported here for the first time. Internode stem explants of Poinsettia cv. Millenium were transformed by Agrobacterium tumefaciens, strain LBA 4404, harbouring virus-derived hairpin (hp) RNA gene constructs to induce RNA silencing-mediated resistance to Poinsettia mosaic virus (PnMV). Prior to transformation, an efficient somatic embryogenesis system was developed for Poinsettia cv. Millenium in which about 75% of the explants produced somatic embryos. In 5 experiments utilizing 868 explants, 18 independent transgenic lines were generated. An average transformation frequency of 2.1% (range 1.2–3.5%) was revealed. Stable integration of transgenes into the Poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Both single- and multiple-copy transgene integration into the Poinsettia genome were found among transformants. Transgenic Poinsettia plants showing resistance to mechanical inoculation of PnMV were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Northern blot analysis of low molecular weight RNA revealed that transgene-derived small interfering (si) RNA molecules were detected among the Poinsettia transformants prior to inoculation. The Agrobacterium-mediated transformation methodology developed in the current study should facilitate improvement of this ornamental plant with enhanced disease resistance, quality improvement and desirable colour alteration. Because Poinsettia is a non-food, non-feed plant and is not propagated through sexual reproduction, this is likely to be more acceptable even in areas where genetically modified crops are currently not cultivated.
Jihong Liu Clarke - One of the best experts on this subject based on the ideXlab platform.
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Poinsettia ( Euphorbia pulcherrima Willd. ex Klotzsch)
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: M. Ashraful Islam, Tage Thorstensen, Jihong Liu ClarkeAbstract:Genetic engineering is an important tool for introducing desired genes into Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch). We describe in this chapter an Agrobacterium tumefaciens-mediated transformation protocol for Poinsettia. A detailed description of genetic transformation, antibiotic selection, subsequent regeneration via somatic embryogenesis, and rooting as well as molecular and morphological analyses is included. The methodology described here could facilitate the future engineering of Poinsettia for research purpose as well as commercial production of Poinsettia plants with improved resistance or novel traits.
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Overexpression of the AtSHI gene in Poinsettia, Euphorbia pulcherrima, results in compact plants.
PloS one, 2013Co-Authors: M. Ashraful Islam, Sissel Haugslien, Dag-ragnar Blystad, Henrik Lütken, Sissel Torre, Jakub Rolcik, Søren K. Rasmussen, Jorunn E. Olsen, Jihong Liu ClarkeAbstract:Euphorbia pulcherrima, Poinsettia, is a non-food and non-feed vegetatively propagated ornamental plant. Appropriate plant height is one of the most important traits in Poinsettia production and is commonly achieved by application of chemical growth retardants. To produce compact Poinsettia plants with desirable height and reduce the utilization of growth retardants, the Arabidopsis SHORT INTERNODE (AtSHI) gene controlled by the cauliflower mosaic virus 35S promoter was introduced into Poinsettia by Agrobacterium-mediated transformation. Three independent transgenic lines were produced and stable integration of transgene was verified by PCR and Southern blot analysis. Reduced plant height (21–52%) and internode lengths (31–49%) were obtained in the transgenic lines compared to control plants. This correlates positively with the AtSHI transcript levels, with the highest levels in the most dwarfed transgenic line (TL1). The indole-3-acetic acid (IAA) content appeared lower (11–31% reduction) in the transgenic lines compared to the wild type (WT) controls, with the lowest level (31% reduction) in TL1. Total internode numbers, bract numbers and bract area were significantly reduced in all transgenic lines in comparison with the WT controls. Only TL1 showed significantly lower plant diameter, total leaf area and total dry weight, whereas none of the AtSHI expressing lines showed altered timing of flower initiation, cyathia abscission or bract necrosis. This study demonstrated that introduction of the AtSHI gene into Poinsettia by genetic engineering can be an effective approach in controlling plant height without negatively affecting flowering time. This can help to reduce or avoid the use of toxic growth retardants of environmental and human health concern. This is the first report that AtSHI gene was overexpressed in Poinsettia and transgenic Poinsettia plants with compact growth were produced.
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Production of transgenic Poinsettia with resistance against Poinsettia mosaic virus (PNMV) using Agrobacterium-mediated transformation
Acta Horticulturae, 2011Co-Authors: Jihong Liu Clarke, Carl Spetz, Sissel Haugslien, Merete W. Dees, Roar Moe, Dag-ragnar BlystadAbstract:Genetic engineering plays a significant role for the improvement of ornamental crops. Using an Agrobacterium-mediated transformation approach, we have produced transgenic Poinsettia conferring resistance against Poinsettia mosaic virus (PnMV). A. tumefaciens harbouring three hairpin (hp) RNA gene constructs to generate silencing-based resistance to PnMV was introduced into internode stem explants of Poinsettia cultivar Millenium. Stable integration of transgenes into the Poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISA) revealed that resistance to mechanical inoculation of PnMV was found among the transgenic Poinsettia lines, whereas the controls were susceptible. Grafting technique was used to re-introduce the free branching factor, phytoplasma, back to the selected desirable transgenic Poinsettia lines. Subsequently, fresh cuttings derived from these lines with phytoplasma and branches were further investigated for the stability of PnMV resistance and their morphological performance compared with non-transformed controls. Currently, these lines are undergoing evaluation at the grower's facility for future commercialization.
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Agrobacterium tumefaciens-mediated transformation of Poinsettia, Euphorbia pulcherrima, with virus-derived hairpin RNA constructs confers resistance to Poinsettia mosaic virus
Plant cell reports, 2008Co-Authors: Jihong Liu Clarke, Carl Spetz, Sissel Haugslien, Shaochen Xing, Merete W. Dees, Roar Moe, Dag-ragnar BlystadAbstract:Agrobacterium-mediated transformation for Poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch) is reported here for the first time. Internode stem explants of Poinsettia cv. Millenium were transformed by Agrobacterium tumefaciens, strain LBA 4404, harbouring virus-derived hairpin (hp) RNA gene constructs to induce RNA silencing-mediated resistance to Poinsettia mosaic virus (PnMV). Prior to transformation, an efficient somatic embryogenesis system was developed for Poinsettia cv. Millenium in which about 75% of the explants produced somatic embryos. In 5 experiments utilizing 868 explants, 18 independent transgenic lines were generated. An average transformation frequency of 2.1% (range 1.2–3.5%) was revealed. Stable integration of transgenes into the Poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Both single- and multiple-copy transgene integration into the Poinsettia genome were found among transformants. Transgenic Poinsettia plants showing resistance to mechanical inoculation of PnMV were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Northern blot analysis of low molecular weight RNA revealed that transgene-derived small interfering (si) RNA molecules were detected among the Poinsettia transformants prior to inoculation. The Agrobacterium-mediated transformation methodology developed in the current study should facilitate improvement of this ornamental plant with enhanced disease resistance, quality improvement and desirable colour alteration. Because Poinsettia is a non-food, non-feed plant and is not propagated through sexual reproduction, this is likely to be more acceptable even in areas where genetically modified crops are currently not cultivated.
Thomas Debener - One of the best experts on this subject based on the ideXlab platform.
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Hybrid de novo transcriptome assembly of Poinsettia (Euphorbia pulcherrima Willd. Ex Klotsch) bracts
BMC Genomics, 2019Co-Authors: Vinicius Vilperte, Calin Rares Lucaciu, Heidi Halbwirth, Robert Boehm, Thomas Rattei, Thomas DebenerAbstract:Background Poinsettia is a popular and important ornamental crop, mostly during the Christmas season. Its bract coloration ranges from pink/red to creamy/white shades. Despite its ornamental value, there is a lack of knowledge about the genetics and molecular biology of Poinsettia, especially on the mechanisms of color formation. We performed an RNA-Seq analysis in order to shed light on the transcriptome of Poinsettia bracts. Moreover, we analyzed the transcriptome differences of red- and white-bracted Poinsettia varieties during bract development and coloration. For the assembly of a bract transcriptome, two paired-end cDNA libraries from a red and white Poinsettia pair were sequenced with the Illumina technology, and one library from a red-bracted variety was used for PacBio sequencing. Both short and long reads were assembled using a hybrid de novo strategy. Samples of red- and white-bracted Poinsettias were sequenced and comparatively analyzed in three color developmental stages in order to understand the mechanisms of color formation and accumulation in the species. Results The final transcriptome contains 288,524 contigs, with 33% showing confident protein annotation against the TAIR10 database. The BUSCO pipeline, which is based on near-universal orthologous gene groups, was applied to assess the transcriptome completeness. From a total of 1440 BUSCO groups searched, 77% were categorized as complete (41% as single-copy and 36% as duplicated), 10% as fragmented and 13% as missing BUSCOs. The gene expression comparison between red and white varieties of Poinsettia showed a differential regulation of the flavonoid biosynthesis pathway only at particular stages of bract development. An initial impairment of the flavonoid pathway early in the color accumulation process for the white Poinsettia variety was observed, but these differences were no longer present in the subsequent stages of bract development. Nonetheless, GSTF11 and UGT79B10 showed a lower expression in the last stage of bract development for the white variety and, therefore, are potential candidates for further studies on Poinsettia coloration. Conclusions In summary, this transcriptome analysis provides a valuable foundation for further studies on Poinsettia, such as plant breeding and genetics, and highlights crucial information on the molecular mechanism of color formation.
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Hybrid de novo transcriptome assembly of Poinsettia (Euphorbia pulcherrima Willd. Ex Klotsch) bracts.
BMC genomics, 2019Co-Authors: Vinicius Vilperte, Calin Rares Lucaciu, Heidi Halbwirth, Robert Boehm, Thomas Rattei, Thomas DebenerAbstract:Poinsettia is a popular and important ornamental crop, mostly during the Christmas season. Its bract coloration ranges from pink/red to creamy/white shades. Despite its ornamental value, there is a lack of knowledge about the genetics and molecular biology of Poinsettia, especially on the mechanisms of color formation. We performed an RNA-Seq analysis in order to shed light on the transcriptome of Poinsettia bracts. Moreover, we analyzed the transcriptome differences of red- and white-bracted Poinsettia varieties during bract development and coloration. For the assembly of a bract transcriptome, two paired-end cDNA libraries from a red and white Poinsettia pair were sequenced with the Illumina technology, and one library from a red-bracted variety was used for PacBio sequencing. Both short and long reads were assembled using a hybrid de novo strategy. Samples of red- and white-bracted Poinsettias were sequenced and comparatively analyzed in three color developmental stages in order to understand the mechanisms of color formation and accumulation in the species. The final transcriptome contains 288,524 contigs, with 33% showing confident protein annotation against the TAIR10 database. The BUSCO pipeline, which is based on near-universal orthologous gene groups, was applied to assess the transcriptome completeness. From a total of 1440 BUSCO groups searched, 77% were categorized as complete (41% as single-copy and 36% as duplicated), 10% as fragmented and 13% as missing BUSCOs. The gene expression comparison between red and white varieties of Poinsettia showed a differential regulation of the flavonoid biosynthesis pathway only at particular stages of bract development. An initial impairment of the flavonoid pathway early in the color accumulation process for the white Poinsettia variety was observed, but these differences were no longer present in the subsequent stages of bract development. Nonetheless, GSTF11 and UGT79B10 showed a lower expression in the last stage of bract development for the white variety and, therefore, are potential candidates for further studies on Poinsettia coloration. In summary, this transcriptome analysis provides a valuable foundation for further studies on Poinsettia, such as plant breeding and genetics, and highlights crucial information on the molecular mechanism of color formation.
Vinicius Vilperte - One of the best experts on this subject based on the ideXlab platform.
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Hybrid de novo transcriptome assembly of Poinsettia (Euphorbia pulcherrima Willd. Ex Klotsch) bracts
BMC Genomics, 2019Co-Authors: Vinicius Vilperte, Calin Rares Lucaciu, Heidi Halbwirth, Robert Boehm, Thomas Rattei, Thomas DebenerAbstract:Background Poinsettia is a popular and important ornamental crop, mostly during the Christmas season. Its bract coloration ranges from pink/red to creamy/white shades. Despite its ornamental value, there is a lack of knowledge about the genetics and molecular biology of Poinsettia, especially on the mechanisms of color formation. We performed an RNA-Seq analysis in order to shed light on the transcriptome of Poinsettia bracts. Moreover, we analyzed the transcriptome differences of red- and white-bracted Poinsettia varieties during bract development and coloration. For the assembly of a bract transcriptome, two paired-end cDNA libraries from a red and white Poinsettia pair were sequenced with the Illumina technology, and one library from a red-bracted variety was used for PacBio sequencing. Both short and long reads were assembled using a hybrid de novo strategy. Samples of red- and white-bracted Poinsettias were sequenced and comparatively analyzed in three color developmental stages in order to understand the mechanisms of color formation and accumulation in the species. Results The final transcriptome contains 288,524 contigs, with 33% showing confident protein annotation against the TAIR10 database. The BUSCO pipeline, which is based on near-universal orthologous gene groups, was applied to assess the transcriptome completeness. From a total of 1440 BUSCO groups searched, 77% were categorized as complete (41% as single-copy and 36% as duplicated), 10% as fragmented and 13% as missing BUSCOs. The gene expression comparison between red and white varieties of Poinsettia showed a differential regulation of the flavonoid biosynthesis pathway only at particular stages of bract development. An initial impairment of the flavonoid pathway early in the color accumulation process for the white Poinsettia variety was observed, but these differences were no longer present in the subsequent stages of bract development. Nonetheless, GSTF11 and UGT79B10 showed a lower expression in the last stage of bract development for the white variety and, therefore, are potential candidates for further studies on Poinsettia coloration. Conclusions In summary, this transcriptome analysis provides a valuable foundation for further studies on Poinsettia, such as plant breeding and genetics, and highlights crucial information on the molecular mechanism of color formation.
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Hybrid de novo transcriptome assembly of Poinsettia (Euphorbia pulcherrima Willd. Ex Klotsch) bracts.
BMC genomics, 2019Co-Authors: Vinicius Vilperte, Calin Rares Lucaciu, Heidi Halbwirth, Robert Boehm, Thomas Rattei, Thomas DebenerAbstract:Poinsettia is a popular and important ornamental crop, mostly during the Christmas season. Its bract coloration ranges from pink/red to creamy/white shades. Despite its ornamental value, there is a lack of knowledge about the genetics and molecular biology of Poinsettia, especially on the mechanisms of color formation. We performed an RNA-Seq analysis in order to shed light on the transcriptome of Poinsettia bracts. Moreover, we analyzed the transcriptome differences of red- and white-bracted Poinsettia varieties during bract development and coloration. For the assembly of a bract transcriptome, two paired-end cDNA libraries from a red and white Poinsettia pair were sequenced with the Illumina technology, and one library from a red-bracted variety was used for PacBio sequencing. Both short and long reads were assembled using a hybrid de novo strategy. Samples of red- and white-bracted Poinsettias were sequenced and comparatively analyzed in three color developmental stages in order to understand the mechanisms of color formation and accumulation in the species. The final transcriptome contains 288,524 contigs, with 33% showing confident protein annotation against the TAIR10 database. The BUSCO pipeline, which is based on near-universal orthologous gene groups, was applied to assess the transcriptome completeness. From a total of 1440 BUSCO groups searched, 77% were categorized as complete (41% as single-copy and 36% as duplicated), 10% as fragmented and 13% as missing BUSCOs. The gene expression comparison between red and white varieties of Poinsettia showed a differential regulation of the flavonoid biosynthesis pathway only at particular stages of bract development. An initial impairment of the flavonoid pathway early in the color accumulation process for the white Poinsettia variety was observed, but these differences were no longer present in the subsequent stages of bract development. Nonetheless, GSTF11 and UGT79B10 showed a lower expression in the last stage of bract development for the white variety and, therefore, are potential candidates for further studies on Poinsettia coloration. In summary, this transcriptome analysis provides a valuable foundation for further studies on Poinsettia, such as plant breeding and genetics, and highlights crucial information on the molecular mechanism of color formation.
Edgloris Marys - One of the best experts on this subject based on the ideXlab platform.
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Detection of Poinsettia mosaic virus Infecting Poinsettias (Euphorbia pulcherrima) in Venezuela.
Plant disease, 2001Co-Authors: O. Carballo, M. L. Izaguirre, Edgloris MarysAbstract:Poinsettia mosaic virus (PnMV), a putative member of the tymoviruses, was detected in several cultivars of vegetatively propagated Poinsettias grown in commercial nurseries in Estado Miranda, Venezuela. Symptoms associated with the affected plants consisted of severe mottling and distortion of leaves and bracteoles. The suspect virus was mechanically transmitted to Nicotiana benthamiana. Leaf extracts and thin sections of affected leaf tissue were analyzed by transmission electron microscopy. Spherical virus particles (30 nm diameter) were observed in samples from symptomatic Poinsettia plants. Ultrastructural analyses of virus-infected cells revealed aggregates of virus particles in the cytoplasm and central vacuole. The virus was purified twice from infected N. benthamiana, resulting in yields as high as 12 mg/100 g. Dissociated coat protein contained a single 24-kDa protein species. The virus was not serologically related to Carnation mottle, Bean rugose mosaic, Cowpea mosaic, Cucumber mosaic, Pea enation mosaic, Prunus necrotic ringspot, Apple mosaic, Tobacco streak, Maize rayado fino, Tomato ringspot, Bean southern mosaic, Sowbane mosaic, Andean potato latent, Belladona mottle, Scrophularia or Turnip yellow mosaic viruses, but did react positively in enzyme-linked immunosorbent assay and western blot analysis with antiserum (ATCC PVAS-476) to PnMV. Based on these results, the virus is considered to be PnMV. To our knowledge, this is the first report of PnMV infecting Poinsettias in Venezuela.