Potamogeton

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Keiko Kosuge - One of the best experts on this subject based on the ideXlab platform.

  • maternal effects and ecological divergence in aquatic plants a case study in natural reciprocal hybrids between Potamogeton perfoliatus and p wrightii
    Plant Species Biology, 2013
    Co-Authors: Satoko Iida, Yasuro Kadono, Keiko Kosuge
    Abstract:

    When parental taxa are adapted to different habitats, hybrid genotypes are often highly heterogeneous, such that habitat or ecological factors influence hybrid fate and ecological performance. Trait expression in hybrids is not always intermediate between the parents, but may instead be either parental-like or extreme (transgressive) depending on genetic control of the phenotypes. Maternal effects arising from interspecific interaction between cytoplasmic and nuclear genomes are widely recognized as playing a role in character expression of natural hybrids. Such interaction often leads to hybrid sterility or inviability. When hybrids are viable, however, cytonuclear interaction may contribute to hybrid persistence through its influence on trait expression. To date, maternal influence on hybrid performance has been examined primarily in experimentally produced hybrids, or in natural hybrids without identification of the cross direction owing to difficulty in obtaining species-specific molecular markers. In aquatic plants, many hybrids persist by extensive clonal growth and are important components of aquatic communities. Many such hybrids are known in Potamogeton (pondweeds), the largest aquatic genus. Because Potamogeton species are ecologically highly diverse and maternal lineages are readily distinguished using molecular markers, natural hybrids of Potamogeton are well-suited for studies of maternal effects, especially those affecting vegetative performance. As a case study, we have focused on maternal effects on drought tolerance and depth distribution in the natural hybrid P. ¥ anguillanus derived from the closely related species P. perfoliatus and P. wrightii.

  • comparative studies of thermotolerance different modes of heat acclimation between tolerant and intolerant aquatic plants of the genus Potamogeton
    Annals of Botany, 2012
    Co-Authors: Momoe Amano, Satoko Iida, Keiko Kosuge
    Abstract:

    BACKGROUND AND AIMS: Molecular-based studies of thermotolerance have rarely been performed on wild plants, although this trait is critical for summer survival. Here, we focused on thermotolerance and expression of heat shock transcription factor A2 (HSFA2) and its putative target gene (chloroplast-localized small heat shock protein, CP-sHSP) in two allied aquatic species of the genus Potamogeton (pondweeds) that differ in survival on land. METHODS: The degree of thermotolerance was examined using a chlorophyll bioassay to assess heat injury in plants cultivated under non- and heat-acclimation conditions. Potamogeton HSFA2 and CP-sHSP genes were identified and their heat-induction was quantified by real-time PCR. KEY RESULTS: The inhibition of chlorophyll accumulation after heat stress showed that Potamogeton malaianus had a higher basal thermotolerance and developed acquired thermotolerance, whereas Potamogeton perfoliatus was heat sensitive and unable to acquire thermotolerance. We found two duplicated HSFA2 and CP-sHSP genes in each species. These genes were induced by heat shock in P. malaianus, while one HSFA2a gene was not induced in P. perfoliatus. In non-heat-acclimated plants, transcript levels of HSFA2 and CP-sHSP were transiently elevated after heat shock. In heat-acclimated plants, transcripts were continuously induced during sublethal heat shock in P. malaianus, but not in P. perfoliatus. Instead, the minimum threshold temperature for heat induction of the CP-sHSP genes was elevated in P. perfoliatus. CONCLUSIONS: Our comparative study of thermotolerance showed that heat acclimation leads to species-specific changes in heat response. The development of acquired thermotolerance is beneficial for survival at extreme temperatures. However, the loss of acquired thermotolerance and plasticity in the minimum threshold temperature of heat response may be favourable for plants growing in moderate habitats with limited daily and seasonal temperature fluctuations.

  • molecular adaptation of rbcl in the heterophyllous aquatic plant Potamogeton
    PLOS ONE, 2009
    Co-Authors: Satoko Iida, Yasuro Kadono, Atsuko Miyagi, Seishiro Aoki, Keiko Kosuge
    Abstract:

    Background Heterophyllous aquatic plants show marked phenotypic plasticity. They adapt to environmental changes by producing different leaf types: submerged, floating and terrestrial leaves. By contrast, homophyllous plants produce only submerged leaves and grow entirely underwater. Heterophylly and submerged homophylly evolved under selective pressure modifying the species-specific optima for photosynthesis, but little is known about the evolutionary outcome of habit. Recent evolutionary analyses suggested that rbcL, a chloroplast gene that encodes a catalytic subunit of RuBisCO, evolves under positive selection in most land plant lineages. To examine the adaptive evolutionary process linked to heterophylly or homophylly, we analyzed positive selection in the rbcL sequences of ecologically diverse aquatic plants, Japanese Potamogeton. Principal Findings Phylogenetic and maximum likelihood analyses of codon substitution models indicated that Potamogeton rbcL has evolved under positive Darwinian selection. The positive selection has operated specifically in heterophyllous lineages but not in homophyllous ones in the branch-site models. This suggests that the selective pressure on this chloroplast gene was higher for heterophyllous lineages than for homophyllous lineages. The replacement of 12 amino acids occurred at structurally important sites in the quaternary structure of RbcL, two of which (residue 225 and 281) were identified as potentially under positive selection. Conclusions/Significance Our analysis did not show an exact relationship between the amino acid replacements and heterophylly or homophylly but revealed that lineage-specific positive selection acted on the Potamogeton rbcL. The contrasting ecological conditions between heterophyllous and homophyllous plants have imposed different selective pressures on the photosynthetic system. The increased amino acid replacement in RbcL may reflect the continuous fine-tuning of RuBisCO under varying ecological conditions.

  • Molecular phylogeny of Japanese Potamogeton species in light of noncoding chloroplast sequences.
    Aquatic Botany, 2004
    Co-Authors: Satoko Iida, Keiko Kosuge, Yasuro Kadono
    Abstract:

    In the genus Potamogeton, high morphologic and ecologic diversification and difficulty in evaluating systematic usefulness of various characteristics have led to the definition of many small groups of species corresponding to sections or subsections. The 18 species of Japanese Potamogeton that have high variation represent 11 of the 14 species groups proposed in a recent treatment of the genus. We performed phylogenetic analyses of these 18 species of Japanese Potamogeton with three allied genera by using the noncoding region of chloroplast DNA between trnT (UGU) and trnL (UAA). Our phylogenetic tree revealed that Japanese Potamogeton were divided into two main groups (I and II). In general, each group was characterized by the shape of the submerged leaves and anatomic features of the stem. Group I comprised eight species with broad submerged leaves, and these species lacked sub-epidermal bundles in the stem. Group II comprisesd 10 species characterized by linear submerged leaves and the presence of sub-epidermal bundles. Group II was further divided into two subgroups (IIa and IIb). Subgroup IIa taxa did not have a dormant period or physiologically specialized turions, and the stele was of the trio or proto-type. In comparison, subgroup IIb members have dormant period in the form of axillary or apical turions, and stele types were oblong or circular. Potamogeton crispus and P. maackianus, each of which has distinct morphology and ecology, are included in group I but differed from the other Potamogeton in having unique length mutations and substitutions in the trnT–trnL sequence.

Zdenek Kaplan - One of the best experts on this subject based on the ideXlab platform.

  • Potamogeton ×jacobsii (Potamogetonaceae) from New South Wales, Australia - the first Potamogeton hybrid from the Southern Hemisphere
    2020
    Co-Authors: Zdenek Kaplan, Judith Fehrer, C. Barre Hellquist
    Abstract:

    Although more than 80 hybrids are documented for Potamogeton in the Northern Hemisphere, the hybrid diversity in the Southern Hemisphere is largely unknown. A taxonomically uncertain Potamogeton plant discovered in New South Wales, Australia, was subjected to detailed morphological investigation and molecular analyses to discover its exact identity. Both approaches resulted in the identification of the Potamogeton specimen as P. crispus × P. ochreatus, which is a previously unrecorded hybrid and is here described as Potamogeton × jacobsii nothosp. nova. Although P. crispus is known to hybridise with many other species, P. ×jacobsii is the first known hybrid involving P. ochreatus.

  • Potamogeton taxa proposed by J. F. Wolfgang and his collaborators
    Taxon, 2020
    Co-Authors: Zdenek Kaplan, Joanna Zalewska-gałosz
    Abstract:

    In the first half of 19 t h century Jan Fryderyk Wolfgang (1775-1859) was the outstanding expert on Potamogetonaceae. Twelve of the names he proposed in a manuscript of a monograph on Potamogeton were validly published bySchultes & Schultes (1827). Of these, four names are now the correct names for the respective taxa, one for a species (P. rutilus Wolfg.) and three for hybrids (P × nerviger Wolfg., P × salicifolius Wolfg. and P × undulatus Wolfg.). Ten names of Potamogeton taxa described by Wolfgang are typified in this paper, together with two names proposed by his collaborators, Besser and Gorski. The identity of these names is discussed.

  • Taxonomic identity and typification of selected names of North American Potamogetonaceae
    Brittonia, 2013
    Co-Authors: Zdenek Kaplan, James L. Reveal
    Abstract:

    Most names in North American Potamogetonaceae have not been typified. Details of typifications are given for 72 names based on North American material published in the genus Potamogeton mainly by North American botanists. All names are reviewed for their nomenclatural validity and legitimacy, and interpreted taxonomically. Holotypes are indicated for 31 names and previously declared lectotypes or neotypes are listed for eight names. Lectotypes are designated for 24 previously untypified names and step-2 lectotypifications are proposed for three names that were based on heterogeneous material. Type material for three Rafinesque names and one proposed by Wood have not been located. An annotated list provides collection data, type status, homotypic synonyms, and currently accepted names. Two names are excluded from Potamogeton , being based on species of Myriophyllum (Haloragaceae).

  • discovery of a new recurrently formed Potamogeton hybrid in europe and africa molecular evidence and morphological comparison of different clones
    Taxon, 2010
    Co-Authors: Joanna Zalewskagalosz, Michal Ronikier, Zdenek Kaplan
    Abstract:

    A new Potamogeton hybrid resulting from crossing between P. nodosus and P. perfoliatus, and occurring in Europe and Africa is described here as P. ×assidens. The hybrid identity was unequivocally confirmed by molecular study of ITS and selected chloroplast DNA regions. In European populations, for which the maternal taxon was identified based on cpDNA as P. nodosus, maternally driven expression of characters may account to a large degree for shaping the range of morphological variability of the hybrid taxon. This was accompanied by a matroclinal concerted evolution observed at the molecular level in the ITS sequences. Our observations may suggest the presence of some genetic mechanisms that promote a higher impact of the maternal lineage on the expression and evolution of the hybrid variability both at the molecular (direction of concerted evolution in hybrids) and the morphological level. Distinctive characters of P. ×assidens and other morphologically close Potamogeton hybrids are discussed. The hybrid most similar to P. xassidens, namely P. ×rectifolius, is typified.

  • new hybrid combinations revealed by molecular analysis the unknown side of north american pondweed diversity Potamogeton
    Systematic Botany, 2009
    Co-Authors: Zdenek Kaplan, Judith Fehrer, Barre C Hellquist
    Abstract:

    Abstract The occurrence and diversity of Potamogeton hybrids was investigated in eastern North America, the region of the highest diversity of Potamogeton species in the world. For various reasons, however, the existence of hybrids in this area has been largely overlooked. ITS direct sequencing and RFLPs revealed four previously unknown hybrids, which are described as Potamogeton ×aemulans (P. bicupulatus × P. epihydrus), P. ×mirabilis (P. gramineus × P. oakesianus), P. ×versicolor (P. epihydrus × P. perfoliatus), and P. ×absconditus (P. perfoliatus × P. richardsonii). These are the first confirmed hybrids involving P. bicupulatus, P. epihydrus, P. oakesianus, and P. richardsonii. Another hybrid, P. ×nitens (P. gramineus × P. perfoliatus), is for the first time confirmed for North America with molecular markers. The hybrids' maternal parents were revealed by cpDNA sequencing. Phenotypically, two of the hybrids more closely resemble other taxa than their parents. Hybrid diversity and recognition in North A...

Kurt Hostettmann - One of the best experts on this subject based on the ideXlab platform.

  • identification of the polar constituents of Potamogeton species by hplc uv with post column derivatization hplc msn and hplc nmr and isolation of a new ent labdane diglycoside
    Phytochemistry, 2004
    Co-Authors: Patrice Waridel, Jeanluc Wolfender, Jeanbernard Lachavanne, Kurt Hostettmann
    Abstract:

    The polar extracts of Potamogeton pectinatus, P. lucens, P. perfoliatus and P. crispus (Potamogetonaceae) were analyzed by HPLC-UV-MS and their chromatographic profiles were very similar. The polar constituents of P. pectinatus were more exhaustively investigated by HPLC-UV with post-column derivatization, HPLC-MSn and HPLC-NMR, which allowed the on-line identification of various known flavones (dereplication). One of these compounds, luteolin 3'-O-glucoside, has never been characterized in the Potamogeton genus. The HPLC-UV-MS and HPLC-NMR analyses revealed also the presence of ent-labdane diterpene glycosides in the polar extracts of P. pectinatus and P. lucens and led to the isolation of a new ent-labdane diglycoside from P. pectinatus, beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-15,16-epoxy-12-oxo-8(17),13(16),14-ent-labdatrien-19-oate. (C) 2004 Elsevier Ltd. All rights reserved.

  • ent labdane glycosides from the aquatic plant Potamogeton lucens and analytical evaluation of the lipophilic extract constituents of various Potamogeton species
    Phytochemistry, 2004
    Co-Authors: Patrice Waridel, Jeanluc Wolfender, Jeanbernard Lachavanne, Kurt Hostettmann
    Abstract:

    Abstract Two new ent -labdane glycosides, one known furano- ent -labdane and a new hydroxylated fatty acid were isolated from the dichloromethane extract of the freshwater aquatic plant Potamogeton lucens. The new compounds were assigned the structures of β- d -glucopyranosyl-8(17),13 -ent -labdadien-16,15-olid-18-oate, 18-β- d -glucopyranosyloxy-8(17),13 -ent -labdadien-16,15-olide and 13( R )-hydroxy-octadeca-(9 Z ,11 E ,15 Z )-trien-oic acid by spectroscopic means. The algicidal activity of these compounds was tested against Raphidocelis subcapitata . Based on our previous study of Potamogeton pectinatus , other constituents were identified in P. lucens by LC–UV–MS, LC–NMR and GC–MS. The lipophilic extract profiles of both species are presented. Two other species, Potamogeton perfoliatus and P. crispus, were also investigated by analytical comparison of their non-polar extracts. The distribution of ent -labdanes characterized in Potamogeton is summarized.

Satoko Iida - One of the best experts on this subject based on the ideXlab platform.

  • maternal effects and ecological divergence in aquatic plants a case study in natural reciprocal hybrids between Potamogeton perfoliatus and p wrightii
    Plant Species Biology, 2013
    Co-Authors: Satoko Iida, Yasuro Kadono, Keiko Kosuge
    Abstract:

    When parental taxa are adapted to different habitats, hybrid genotypes are often highly heterogeneous, such that habitat or ecological factors influence hybrid fate and ecological performance. Trait expression in hybrids is not always intermediate between the parents, but may instead be either parental-like or extreme (transgressive) depending on genetic control of the phenotypes. Maternal effects arising from interspecific interaction between cytoplasmic and nuclear genomes are widely recognized as playing a role in character expression of natural hybrids. Such interaction often leads to hybrid sterility or inviability. When hybrids are viable, however, cytonuclear interaction may contribute to hybrid persistence through its influence on trait expression. To date, maternal influence on hybrid performance has been examined primarily in experimentally produced hybrids, or in natural hybrids without identification of the cross direction owing to difficulty in obtaining species-specific molecular markers. In aquatic plants, many hybrids persist by extensive clonal growth and are important components of aquatic communities. Many such hybrids are known in Potamogeton (pondweeds), the largest aquatic genus. Because Potamogeton species are ecologically highly diverse and maternal lineages are readily distinguished using molecular markers, natural hybrids of Potamogeton are well-suited for studies of maternal effects, especially those affecting vegetative performance. As a case study, we have focused on maternal effects on drought tolerance and depth distribution in the natural hybrid P. ¥ anguillanus derived from the closely related species P. perfoliatus and P. wrightii.

  • comparative studies of thermotolerance different modes of heat acclimation between tolerant and intolerant aquatic plants of the genus Potamogeton
    Annals of Botany, 2012
    Co-Authors: Momoe Amano, Satoko Iida, Keiko Kosuge
    Abstract:

    BACKGROUND AND AIMS: Molecular-based studies of thermotolerance have rarely been performed on wild plants, although this trait is critical for summer survival. Here, we focused on thermotolerance and expression of heat shock transcription factor A2 (HSFA2) and its putative target gene (chloroplast-localized small heat shock protein, CP-sHSP) in two allied aquatic species of the genus Potamogeton (pondweeds) that differ in survival on land. METHODS: The degree of thermotolerance was examined using a chlorophyll bioassay to assess heat injury in plants cultivated under non- and heat-acclimation conditions. Potamogeton HSFA2 and CP-sHSP genes were identified and their heat-induction was quantified by real-time PCR. KEY RESULTS: The inhibition of chlorophyll accumulation after heat stress showed that Potamogeton malaianus had a higher basal thermotolerance and developed acquired thermotolerance, whereas Potamogeton perfoliatus was heat sensitive and unable to acquire thermotolerance. We found two duplicated HSFA2 and CP-sHSP genes in each species. These genes were induced by heat shock in P. malaianus, while one HSFA2a gene was not induced in P. perfoliatus. In non-heat-acclimated plants, transcript levels of HSFA2 and CP-sHSP were transiently elevated after heat shock. In heat-acclimated plants, transcripts were continuously induced during sublethal heat shock in P. malaianus, but not in P. perfoliatus. Instead, the minimum threshold temperature for heat induction of the CP-sHSP genes was elevated in P. perfoliatus. CONCLUSIONS: Our comparative study of thermotolerance showed that heat acclimation leads to species-specific changes in heat response. The development of acquired thermotolerance is beneficial for survival at extreme temperatures. However, the loss of acquired thermotolerance and plasticity in the minimum threshold temperature of heat response may be favourable for plants growing in moderate habitats with limited daily and seasonal temperature fluctuations.

  • molecular adaptation of rbcl in the heterophyllous aquatic plant Potamogeton
    PLOS ONE, 2009
    Co-Authors: Satoko Iida, Yasuro Kadono, Atsuko Miyagi, Seishiro Aoki, Keiko Kosuge
    Abstract:

    Background Heterophyllous aquatic plants show marked phenotypic plasticity. They adapt to environmental changes by producing different leaf types: submerged, floating and terrestrial leaves. By contrast, homophyllous plants produce only submerged leaves and grow entirely underwater. Heterophylly and submerged homophylly evolved under selective pressure modifying the species-specific optima for photosynthesis, but little is known about the evolutionary outcome of habit. Recent evolutionary analyses suggested that rbcL, a chloroplast gene that encodes a catalytic subunit of RuBisCO, evolves under positive selection in most land plant lineages. To examine the adaptive evolutionary process linked to heterophylly or homophylly, we analyzed positive selection in the rbcL sequences of ecologically diverse aquatic plants, Japanese Potamogeton. Principal Findings Phylogenetic and maximum likelihood analyses of codon substitution models indicated that Potamogeton rbcL has evolved under positive Darwinian selection. The positive selection has operated specifically in heterophyllous lineages but not in homophyllous ones in the branch-site models. This suggests that the selective pressure on this chloroplast gene was higher for heterophyllous lineages than for homophyllous lineages. The replacement of 12 amino acids occurred at structurally important sites in the quaternary structure of RbcL, two of which (residue 225 and 281) were identified as potentially under positive selection. Conclusions/Significance Our analysis did not show an exact relationship between the amino acid replacements and heterophylly or homophylly but revealed that lineage-specific positive selection acted on the Potamogeton rbcL. The contrasting ecological conditions between heterophyllous and homophyllous plants have imposed different selective pressures on the photosynthetic system. The increased amino acid replacement in RbcL may reflect the continuous fine-tuning of RuBisCO under varying ecological conditions.

  • Molecular phylogeny of Japanese Potamogeton species in light of noncoding chloroplast sequences.
    Aquatic Botany, 2004
    Co-Authors: Satoko Iida, Keiko Kosuge, Yasuro Kadono
    Abstract:

    In the genus Potamogeton, high morphologic and ecologic diversification and difficulty in evaluating systematic usefulness of various characteristics have led to the definition of many small groups of species corresponding to sections or subsections. The 18 species of Japanese Potamogeton that have high variation represent 11 of the 14 species groups proposed in a recent treatment of the genus. We performed phylogenetic analyses of these 18 species of Japanese Potamogeton with three allied genera by using the noncoding region of chloroplast DNA between trnT (UGU) and trnL (UAA). Our phylogenetic tree revealed that Japanese Potamogeton were divided into two main groups (I and II). In general, each group was characterized by the shape of the submerged leaves and anatomic features of the stem. Group I comprised eight species with broad submerged leaves, and these species lacked sub-epidermal bundles in the stem. Group II comprisesd 10 species characterized by linear submerged leaves and the presence of sub-epidermal bundles. Group II was further divided into two subgroups (IIa and IIb). Subgroup IIa taxa did not have a dormant period or physiologically specialized turions, and the stele was of the trio or proto-type. In comparison, subgroup IIb members have dormant period in the form of axillary or apical turions, and stele types were oblong or circular. Potamogeton crispus and P. maackianus, each of which has distinct morphology and ecology, are included in group I but differed from the other Potamogeton in having unique length mutations and substitutions in the trnT–trnL sequence.

Patrice Waridel - One of the best experts on this subject based on the ideXlab platform.

  • identification of the polar constituents of Potamogeton species by hplc uv with post column derivatization hplc msn and hplc nmr and isolation of a new ent labdane diglycoside
    Phytochemistry, 2004
    Co-Authors: Patrice Waridel, Jeanluc Wolfender, Jeanbernard Lachavanne, Kurt Hostettmann
    Abstract:

    The polar extracts of Potamogeton pectinatus, P. lucens, P. perfoliatus and P. crispus (Potamogetonaceae) were analyzed by HPLC-UV-MS and their chromatographic profiles were very similar. The polar constituents of P. pectinatus were more exhaustively investigated by HPLC-UV with post-column derivatization, HPLC-MSn and HPLC-NMR, which allowed the on-line identification of various known flavones (dereplication). One of these compounds, luteolin 3'-O-glucoside, has never been characterized in the Potamogeton genus. The HPLC-UV-MS and HPLC-NMR analyses revealed also the presence of ent-labdane diterpene glycosides in the polar extracts of P. pectinatus and P. lucens and led to the isolation of a new ent-labdane diglycoside from P. pectinatus, beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-15,16-epoxy-12-oxo-8(17),13(16),14-ent-labdatrien-19-oate. (C) 2004 Elsevier Ltd. All rights reserved.

  • ent labdane glycosides from the aquatic plant Potamogeton lucens and analytical evaluation of the lipophilic extract constituents of various Potamogeton species
    Phytochemistry, 2004
    Co-Authors: Patrice Waridel, Jeanluc Wolfender, Jeanbernard Lachavanne, Kurt Hostettmann
    Abstract:

    Abstract Two new ent -labdane glycosides, one known furano- ent -labdane and a new hydroxylated fatty acid were isolated from the dichloromethane extract of the freshwater aquatic plant Potamogeton lucens. The new compounds were assigned the structures of β- d -glucopyranosyl-8(17),13 -ent -labdadien-16,15-olid-18-oate, 18-β- d -glucopyranosyloxy-8(17),13 -ent -labdadien-16,15-olide and 13( R )-hydroxy-octadeca-(9 Z ,11 E ,15 Z )-trien-oic acid by spectroscopic means. The algicidal activity of these compounds was tested against Raphidocelis subcapitata . Based on our previous study of Potamogeton pectinatus , other constituents were identified in P. lucens by LC–UV–MS, LC–NMR and GC–MS. The lipophilic extract profiles of both species are presented. Two other species, Potamogeton perfoliatus and P. crispus, were also investigated by analytical comparison of their non-polar extracts. The distribution of ent -labdanes characterized in Potamogeton is summarized.