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David Zaitlin - One of the best experts on this subject based on the ideXlab platform.

  • intraspecific diversity in sinningia speciosa gesneriaceae sinningieae and possible origins of the cultivated florist s Gloxinia
    Aob Plants, 2012
    Co-Authors: David Zaitlin
    Abstract:

    Background and aims The florist’s Gloxinia is a familiar houseplant in the Gesneriaceae, the botanical family that includes the African violet (Saintpaulia) and other ornamental species. The Gloxinia’s wild progenitor is Sinningia speciosa (Lodd.) Hiern, a Brazilian endemic. Although it has been cultivated for almost 200 years, little is known about the genetic diversity in S. speciosa, how the wild populations relate to one another or even where the cultivated forms originated. Using available wild collections, preliminary phenetic and phylogenetic investigations were conducted to elucidate the interspecific relationships within S. speciosa and to infer the origins of the cultivars. Methodology Amplified fragment length polymorphism (AFLP) analysis was applied to 24 accessions of S. speciosa (17 wild collections, seven cultivars) and one accession each of Sinningia guttata and Sinningia macrophylla. A maximum likelihood (ML) tree was also calculated from an alignment of the nuclear ribosomal internal transcribed spacer sequence from the same 26 accessions. Principal results Dice/UPGMA and principal coordinates analysis of the AFLP data partitioned S. speciosa into several distinct clusters, one of which included S. macrophylla. All cultivated ‘Gloxinias’ grouped together in a major cluster with plants from Rio de Janeiro. The AFLP results were compared with a phylogenetic analysis of the ribosomal spacer region, which was informative in S. speciosa. The ML tree generally supported the AFLP results, although several clades lacked strong statistical support. Conclusions Independent analyses of two different data sets show that S. speciosa is a diverse species comprised of several lineages. Genetic distance estimates calculated from the AFLP data were positively correlated with geographic distances between populations, indicating that reproductive isolation could be driving speciation in this taxon. Molecular markers are under development for population genetic studies in S. speciosa, which will make it possible to define evolutionarily significant units for purposes of conservation.

  • Intraspecific Diversity in Sinningia speciosa (Gesneriaceae: Sinningieae), and Possible Origins of the Cultivated Florist’s Gloxinia
    Aob Plants, 2012
    Co-Authors: David Zaitlin
    Abstract:

    Background and aims The florist’s Gloxinia is a familiar houseplant in the Gesneriaceae, the botanical family that includes the African violet (Saintpaulia) and other ornamental species. The Gloxinia’s wild progenitor is Sinningia speciosa (Lodd.) Hiern, a Brazilian endemic. Although it has been cultivated for almost 200 years, little is known about the genetic diversity in S. speciosa, how the wild populations relate to one another or even where the cultivated forms originated. Using available wild collections, preliminary phenetic and phylogenetic investigations were conducted to elucidate the interspecific relationships within S. speciosa and to infer the origins of the cultivars. Methodology Amplified fragment length polymorphism (AFLP) analysis was applied to 24 accessions of S. speciosa (17 wild collections, seven cultivars) and one accession each of Sinningia guttata and Sinningia macrophylla. A maximum likelihood (ML) tree was also calculated from an alignment of the nuclear ribosomal internal transcribed spacer sequence from the same 26 accessions. Principal results Dice/UPGMA and principal coordinates analysis of the AFLP data partitioned S. speciosa into several distinct clusters, one of which included S. macrophylla. All cultivated ‘Gloxinias’ grouped together in a major cluster with plants from Rio de Janeiro. The AFLP results were compared with a phylogenetic analysis of the ribosomal spacer region, which was informative in S. speciosa. The ML tree generally supported the AFLP results, although several clades lacked strong statistical support. Conclusions Independent analyses of two different data sets show that S. speciosa is a diverse species comprised of several lineages. Genetic distance estimates calculated from the AFLP data were positively correlated with geographic distances between populations, indicating that reproductive isolation could be driving speciation in this taxon. Molecular markers are under development for population genetic studies in S. speciosa, which will make it possible to define evolutionarily significant units for purposes of conservation.

Junhui Wang - One of the best experts on this subject based on the ideXlab platform.

  • flowering time control in ornamental Gloxinia sinningia speciosa by manipulation of mir159 expression
    Annals of Botany, 2013
    Co-Authors: Xiaoyan Li, Hongwu Bian, Dafeng Song, Junhui Wang
    Abstract:

    Background and aims Gloxinia (Sinningia speciosa) is a popular commercial plant for its attractive and colourful flowers. However, the genetic mechanism of flowering time regulation in Gloxinia is largely unknown. Recent studies on model plants have elucidated that miR159 acts as a negative regulator of floral transition in short-day photoperiods. The aim of this study was to investigate whether genetic modification of miR159 expression can offer an effective approach for regulation of flowering characteristics in Gloxinia. Methods Transgenic Gloxinia plants were generated that over-express or suppress miR159 by means an efficient Agrobacterium-mediated transformation system in order to study the effect of miR159 on flowering time. In addition, the full-length cDNA of Gloxinia GAMYB (SsGAMYB) was also cloned, and was verified to be a target of miR159 by modified RNA ligase-mediated 5' rapid amplification of cDNA ends. Key results Transgenic Gloxinia plants that over-express or suppress miR159 exhibited significantly late or early flowering, respectively. During flower development, the expression level of miR159 was negatively correlated with SsGAMYB in Gloxinia. MiR159-mediated SsGAMYB expression affected the expression levels of SsLEAFY (SsLFY) and three MADS-box genes (SsAP1, SsAP3 and SsAG), which regulated floral transition downstream of GAMYB. In addition, suppression of miR159 caused a conversion of petals and sepals in a few transgenic plants. Conclusions miR159-regulated GAMYB expression is an effective pathway of flowering time control in Gloxinia. Transgenic manipulation of miR159 can be used as an applicable strategy to regulate flowering time in commercial ornamental plants.

  • overexpression of the cucumber leafy homolog cfl and hormone treatments alter flower development in Gloxinia sinningia speciosa
    Plant Molecular Biology, 2008
    Co-Authors: Mingzhe Zhang, Hongwu Bian, Dan Ye, Lilin Wang, Jiliang Pang, Yuhong Zhang, Ke Zheng, Junhui Wang
    Abstract:

    Leafy (LFY) and LFY-like genes control the initiation of floral meristems and regulate MADS-box genes in higher plants. The Cucumber-FLO-LFY (CFL) gene, a LFY homolog in Cucumis sativus L. is expressed in the primordia, floral primordia, and each whirl of floral organs during the early stage of flower development. In this study, functions of CFL in flower development were investigated by overexpressing the CFL gene in Gloxinia (Sinningia speciosa). Our results show that constitutive CFL overexpression significantly promote early flowering without gibberellin (GA3) supplement, suggesting that CFL can serve functionally as a LFY homolog in Gloxinia. Moreover, GA3 and abscisic acid (ABA) treatments could modulate the expression of MADS-box genes in opposite directions. GA3 resembles the overexpression of CFL in the expression of MADS-box genes and the regeneration of floral buds, but ABA inhibits the expression of MADS-box genes and flower development. These results suggest that CFL and downstream MADS-box genes involved in flower development are regulated by GA3 and ABA.

Hongwu Bian - One of the best experts on this subject based on the ideXlab platform.

  • regulation of flowering time via mir172 mediated apetala2 like expression in ornamental Gloxinia sinningia speciosa
    Journal of Zhejiang University-science B, 2019
    Co-Authors: Xiaoyan Li, Hongwu Bian
    Abstract:

    : We investigated the microRNA172 (miR172)-mediated regulatory network for the perception of changes in external and endogenous signals to identify a universally applicable floral regulation system in ornamental plants, manipulation of which could be economically beneficial. Transgenic Gloxinia plants, in which miR172 was either overexpressed or suppressed, were generated using Agrobacterium-mediated transformation. They were used to study the effect of altering the expression of this miRNA on time of flowering and to identify its mRNA target. Early or late flowering was observed in transgenic plants in which miR172 was overexpressed or suppressed, respectively. A full-length complementary DNA (cDNA) of Gloxinia (Sinningia speciosa) APETALA2-like (SsAP2-like) was identified as a target of miR172. The altered expression levels of miR172 caused up- or down-regulation of SsAP2-like during flower development, which affected the time of flowering. Quantitative real-time reverse transcription PCR analysis of different Gloxinia tissues revealed that the accumulation of SsAP2-like was negatively correlated with the expression of miR172a, whereas the expression pattern of miR172a was negatively correlated with that of miR156a. Our results suggest that transgenic manipulation of miR172 could be used as a universal strategy for regulating time of flowering in ornamental plants.

  • flowering time control in ornamental Gloxinia sinningia speciosa by manipulation of mir159 expression
    Annals of Botany, 2013
    Co-Authors: Xiaoyan Li, Hongwu Bian, Dafeng Song, Junhui Wang
    Abstract:

    Background and aims Gloxinia (Sinningia speciosa) is a popular commercial plant for its attractive and colourful flowers. However, the genetic mechanism of flowering time regulation in Gloxinia is largely unknown. Recent studies on model plants have elucidated that miR159 acts as a negative regulator of floral transition in short-day photoperiods. The aim of this study was to investigate whether genetic modification of miR159 expression can offer an effective approach for regulation of flowering characteristics in Gloxinia. Methods Transgenic Gloxinia plants were generated that over-express or suppress miR159 by means an efficient Agrobacterium-mediated transformation system in order to study the effect of miR159 on flowering time. In addition, the full-length cDNA of Gloxinia GAMYB (SsGAMYB) was also cloned, and was verified to be a target of miR159 by modified RNA ligase-mediated 5' rapid amplification of cDNA ends. Key results Transgenic Gloxinia plants that over-express or suppress miR159 exhibited significantly late or early flowering, respectively. During flower development, the expression level of miR159 was negatively correlated with SsGAMYB in Gloxinia. MiR159-mediated SsGAMYB expression affected the expression levels of SsLEAFY (SsLFY) and three MADS-box genes (SsAP1, SsAP3 and SsAG), which regulated floral transition downstream of GAMYB. In addition, suppression of miR159 caused a conversion of petals and sepals in a few transgenic plants. Conclusions miR159-regulated GAMYB expression is an effective pathway of flowering time control in Gloxinia. Transgenic manipulation of miR159 can be used as an applicable strategy to regulate flowering time in commercial ornamental plants.

  • sucrose treatment alters floral induction and development in vitro in Gloxinia
    In Vitro Cellular & Developmental Biology – Plant, 2012
    Co-Authors: Mingzhe Zhang, Liling Wang, Dan Ye, Xi Chen, Zhiyi Wu, Wujian Chen, Hongwu Bian
    Abstract:

    Previous studies have shown that Cucumber-FLO-LFY (CFL) overexpression significantly promotes early flowering without a gibberellin (GA3) supplement in Gloxinia (Sinningia speciosa), suggesting that CFL can serve functionally as a LEAFY homolog. In the present study, different sucrose concentrations were applied to the culture medium to investigate the effects of sucrose on the development of excised flower buds and the regeneration of floral buds from sepals in wild-type and 35S::CFL Gloxinia lines. The results showed that floral buds were formed directly from sepal explants without prior formation of shoots and leaves in 35S::CFL Gloxinia lines when 2% w/v sucrose was added. Conversely, 0% or 5% w/v sucrose inhibited the generation of flower buds from sepals and the opening of flowers. Semi-quantitative PCR also showed that a medium with 5% w/v sucrose significantly inhibited MADS-box gene expression in wild type and much less significantly in 35S::CFL Gloxinia. These data indicate that sucrose, as the main carbohydrate transported in floral organs, is a significant promoter of flower induction and maturity.

  • overexpression of the cucumber leafy homolog cfl and hormone treatments alter flower development in Gloxinia sinningia speciosa
    Plant Molecular Biology, 2008
    Co-Authors: Mingzhe Zhang, Hongwu Bian, Dan Ye, Lilin Wang, Jiliang Pang, Yuhong Zhang, Ke Zheng, Junhui Wang
    Abstract:

    Leafy (LFY) and LFY-like genes control the initiation of floral meristems and regulate MADS-box genes in higher plants. The Cucumber-FLO-LFY (CFL) gene, a LFY homolog in Cucumis sativus L. is expressed in the primordia, floral primordia, and each whirl of floral organs during the early stage of flower development. In this study, functions of CFL in flower development were investigated by overexpressing the CFL gene in Gloxinia (Sinningia speciosa). Our results show that constitutive CFL overexpression significantly promote early flowering without gibberellin (GA3) supplement, suggesting that CFL can serve functionally as a LFY homolog in Gloxinia. Moreover, GA3 and abscisic acid (ABA) treatments could modulate the expression of MADS-box genes in opposite directions. GA3 resembles the overexpression of CFL in the expression of MADS-box genes and the regeneration of floral buds, but ABA inhibits the expression of MADS-box genes and flower development. These results suggest that CFL and downstream MADS-box genes involved in flower development are regulated by GA3 and ABA.

Martine Maes - One of the best experts on this subject based on the ideXlab platform.

  • first report of phytophthora stem rot on Gloxinia in bulgaria
    Plant Disease, 2008
    Co-Authors: S G Bobev, K Van Poucke, Martine Maes
    Abstract:

    Severe stem base necrosis was observed on potted Gloxinia (Sinningia speciosa) plants in a greenhouse in the Plovdiv Region of Bulgaria in the spring of 2006 and sporadically in 2007. Initial symptoms were water-soaked lesions at the stem base; eventually the lesions spread upward and downward until the entire stem was affected, resulting in withered leaves and plant collapse. Disease foci were sometimes apparent in rows of plants because of water splash. White, fungal-like colonies with arachnoid, aerial mycelia were obtained from affected plant tissue placed on potato dextrose agar (PDA) at 24 to 25°C in the dark. Pyriform to ellipsoid sporangia, 30 to 55 × 23 to 40 μm (average 38 × 27 μm), with a prominent papilla (sometimes two) and a short pedicel were observed. Chlamydospores were intercalary or terminal, spherical, and 15 to 55 μm in diameter. Oogonia and antheridia were not observed. On the basis of morphological features, the pathogen was tentatively identified as Phytophthora nicotianae (2). Pat...

Chun-neng Wang - One of the best experts on this subject based on the ideXlab platform.

  • Quantitative Evaluation of the Floral Shape Variation in Sinningia Speciosa Domestication
    2013 Kansas City Missouri July 21 - July 24 2013, 2020
    Co-Authors: Li-kang Weng, Chun-neng Wang
    Abstract:

    Abstract. Floral shape variation is of substantial interests to botanists and evolutionary biologists. This study quantifies shape variation in Darwin’s Gloxinia (Sinningia speciosa) using image processing and geometric morphometric methods. Darwin’s Gloxinia has two shape forms – bilateral symmetric (zygomorphic) wild type and radially symmetric (actinomorphic) ornamental breeding (peloria). It is characterized by its easy crossing within its species; hence, is selected to be the study object in this research. In this work, the wild type Darwin’s Gloxinia was crossed with the peloric one. Face and side views of flowers of second-generation hybrids photographed using a regular digital camera. Image processing algorithms were applied to isolate the flowers from the background, and to identify landmarks, i.e., the characteristic points on the flowers. Generalized Procrustes analysis was applied to the landmarks to define floral shapes by excluding their size, rotation, or transformation information. The variation in floral shapes was then investigated by principal component analysis. It was found that the first few principal components captured most structure variations. It is also shown that the proposed approach can adequately capture the shape variation and symmetry in Darwin’s Gloxinia.

  • Shoot regeneration process and optimization of Agrobacterium-mediated transformation in Sinningia speciosa
    Plant Cell Tissue and Organ Culture (PCTOC), 2018
    Co-Authors: Wen-hsi Kuo, Yu-ling Hung, Ho-wei Wu, Zhao-jun Pan, Chwan-yang Hong, Chun-neng Wang
    Abstract:

    The florist’s Gloxinia, Sinningia speciosa, which bears considerable flower trait variations, is an emerging model plants to study floral traits development. However, the investigation of the genetic information linking these floral traits is limited due to a lack of a reliable and efficient transformation system for functional studies. This study aims to optimize a stable genetic transformation system for S. speciosa. Detailed regeneration process and tissue culture parameters are also elucidated. The results show that the plant regeneration, initiated from a single perivascular parenchyma cell, can be induced from leaf and petiole explants in the presence of 1 mg/mL 6-benzylaminopurine (BA) and 0.1 mg/mL naphthalene-acetic acid (NAA) through embryogenesis. In the presence of 0.1 mg/mL NAA only, the adventitious roots form prior to the re-differentiation of shoot tissues in leaf explants. When the proximal end of the petiole is orientated upright with the distal end to the medium, it results in higher success of regeneration, suggesting that hormone supplies must follow endogenous basipetal auxin polarity. Using a glucuronidase (GUS) reporter gene construct, maximum transformation (3.13%) was obtained after a 3 day pre-culture and 5 day co-culture from cotyledons and leaves of 3-week-old seedlings inoculating Agrobacterium strain EHA105. The putative transgenic lines were validated by RT-PCR, Southern blotting and GUS activity. Our result demonstrates that young seedlings are the best material for transformation, probably because young leaves are only a few cell layers thick allowing inner perivascular cell (the origin of regeneration) to be more accessible for Agrobacterium infiltration.

  • Quantifying floral shape variation in 3D using microcomputed tomography: a case study of a hybrid line between actinomorphic and zygomorphic flowers.
    Frontiers in Plant Science, 2015
    Co-Authors: Chun-neng Wang, Cheng-chun Wang
    Abstract:

    The quantification of floral shape variations is difficult because flower structures are both diverse and complex. Traditionally, floral shape variations are quantified using the qualitative and linear measurements of two-dimensional (2D) images. The 2D images cannot adequately describe flower structures, and thus lead to unsatisfactory discrimination of the flower shape. This study aimed to acquire three-dimensional (3D) images by using microcomputed tomography (μCT) and to examine the floral shape variations by using geometric morphometrics (GM). To demonstrate the advantages of the 3D-µCT-GM approach, we applied the approach to a second-generation population of florist’s Gloxinia (Sinningia speciosa) crossed from parents of zygomorphic and actinomorphic flowers. The flowers in the population considerably vary in size and shape, thereby served as good materials to test the applicability of the proposed phenotyping approach. Procedures were developed to acquire 3D volumetric flower images using a μCT scanner, to segment the flower regions from the background, and to select homologous characteristic points (i.e., landmarks) from the flower images for the subsequent GM analysis. The procedures identified 95 landmarks for each flower and thus improved the capability of describing and illustrating the flower shapes, compared with typically lower number of landmarks in 2D analyses. The GM analysis demonstrated that flower opening and dorsoventral symmetry were the principal shape variations of the flowers. The degrees of flower opening and corolla asymmetry were then subsequently quantified directly from the 3D flower images. The 3D-µCT-GM approach revealed shape variations that could not be identified using typical 2D approaches and accurately quantified the flower traits that presented a challenge in 2D images. The approach opens new avenues to investigate floral shape variations.

  • Quantitative analysis of floral symmetry and tube dilation in an F2 cross of Sinningia speciosa
    Scientia Horticulturae, 2015
    Co-Authors: Chia-ying Chen, Li-kang Weng, Chun-neng Wang
    Abstract:

    Shape variation within a flower breeding line is a topic of considerable interest to horticulturalists. Sinningia speciosa (Florist's Gloxinia) is a species that presents diversified floral shapes. This study aimed to quantitatively assess floral shape variation in an F2 cross of S. speciosa between a zygomorphic wild variety and an actinomorphic peloric cultivar via geometric morphometrics. The result indicated symmetric variation and tube dilation accounted for the major variance of floral shape changes. We further tested whether these shape variations can be correlated to any inherited genetic variation. ANOVA analysis detected candidate CYCLOIDEA (SsCYC) marker allele that showed strong associations with variations of corolla symmetry and tube dilation. This study demonstrated that using geometric morphometrics might considerably enhance the detection of phenotypic and genetic association on complex floral shape variation.