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Acer

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Ikuyo Saeki – 1st expert on this subject based on the ideXlab platform

  • comparative phylogeography of red maple Acer rubrum l and silver maple Acer saccharinum l impacts of habitat specialization hybridization and glacial history
    Journal of Biogeography, 2011
    Co-Authors: Ikuyo Saeki, Burton V Barnes, Christopher W Dick, Noriaki Murakami

    Abstract:

    Aim  We analysed variation in chloroplast DNA (cpDNA) in red maple (Acer rubrum L.) and silver maple (Acer saccharinum L.) across a large part of their geographic ranges. Acer rubrum is one of the most common and morphologically variable deciduous trees of eastern North America, while its sister species A. saccharinum has a more restricted habitat distribution and displays markedly less morphological variation. Our objective was to infer the impact of biogeographic history on cpDNA diversity and phylogeographic structure in both species.

    Location  Deciduous forests of eastern North America.

    Methods  We sequenced 1289 to 1645 bp of non-coding cpDNA from A. rubrum (n = 258) and A. saccharinum (n = 83). Maximum parsimony networks and spatial analysis of molecular variance (SAMOVA) were used to analyse phylogeographic structure. Rarefaction analyses were used to compare genetic diversity.

    Results  A total of 40 cpDNA haplotypes were recovered from A. rubrum (38 haplotypes) and A. saccharinum (7 haplotypes). Five of the seven A. saccharinum haplotypes were shared with nearby samples of A. rubrum. SAMOVA recovered four phylogeographic groups for A. rubrum in: (1) south-eastern USA, (2) the Gulf and south-eastern Coastal Plain, (3) the lower Mississippi River Valley, and (4) the central and northern regions of eastern North America. Acer saccharinum had significantly lower haplotype diversity than A. rubrum, and novel haplotypes in post-glaciated northern limits of its range were shared with A. rubrum.

    Main conclusions  This is the first study of A. rubrum to report a distinct phylogeographic group centred on the lower Mississippi River, and the first to examine data comparatively with A. saccharinum. We hypothesized that A. rubrum would display stronger phylogeographic structure and greater haplotype diversity than A. saccharinum because of its greater geographic range, and ecological and morphological variation. This hypothesis was supported by the cpDNA analysis. The sharing of cpDNA and chloroplast simple sequence repeat (cpSSR) haplotypes in areas of geographic overlap provides evidence of introgression, which led to an increase in haplotype diversity in both species, and to novel phylogeographic structure in A. rubrum. We recommend that introgression be considered, along with other potential causes, as an explanation for the phylogeographic structure of cpDNA in plants.

  • Juvenile sprouting ability of the endangered maple, Acer pycnanthum
    Landscape and Ecological Engineering, 2010
    Co-Authors: Ikuyo Saeki

    Abstract:

    Japanese red maple, Acer pycnanthum , is an endangered species having a limited distribution of central Honshu, Japan. Sprouting is an important part of its natural history, and many remnant populations contain high number of multiple-stem clones. However, knowledge of sprout formation and growth is lacking, which has hampered understanding of the reestablishment process after major disturbance. My research objectives were to characterize the formation and growth of basal sprouts in the juvenile stage and determine the effects of light intensity and stump diameter on these characteristics. Twenty sprouting clones were investigated at a natural site in Nagano Prefecture during a four-year period after cutting. Japanese red maple exhibited abundant and vigorous sprouting from the root collar of cut trees. Many sprouts arose immediately after cutting. Average number of sprouts per stump was 12.2. Number of sprouts per stump was negatively correlated with relative light intensity. The two dominant sprouts (sprouts 1 and 2) of each clone were selected to analyze their growth. The average extension growth of sprout 1 (i.e., the tallest and most vigorous) was 173.3 cm at the end of first growing season. At the end of fourth growing season, average height and diameter at breast height (dbh) of sprout 1 were 377 and 2.1 cm, respectively. Relative light intensity and stump diameter significantly and positively affected D^2H (diameter at breast height squared × height) of sprout 1. Because the growth rate of sprouts is much faster than that of seedlings, regeneration by sprouting is more significant than seedling regeneration to maintain populations after disturbances.

  • occurrence and landscape ecology of a rare disjunct maple species Acer pycnanthum and comparison with Acer rubrum
    Environmental Reviews, 2004
    Co-Authors: Burton V Barnes, Ikuyo Saeki, Asako Kitazawa

    Abstract:

    Japanese red maple, Acer pycnanthum K. Koch, is the disjunct sister species of the red maple, Acer rubrum L. Whereas A. rubrum is one of the most widely distributed and abundant species in eastern North America, A. pycnanthum is rare in central Honshu, Japan. Although its morphological similarity to A. rubrum is well known, little is known about the sites and communities where it occurs, its natural history characteristics, sexual and asexual regeneration, and the reasons for its restricted occurrence. We located and described all known sites, totaling <18 ha, which supported populations of three or more clones. Twenty-seven of the 30 ecosystems described are remnant natural populations, which are confined to lower slopes of three river basins where wetlands have persisted and recurrently formed for millions of years due to unique geological, topographic, and soil properties. Acer pycnanthum, an obligate species of forested wetlands, occurs on diverse seepage and floodplain ecosystems that are characteriz…

Noriaki Murakami – 2nd expert on this subject based on the ideXlab platform

  • comparative phylogeography of red maple Acer rubrum l and silver maple Acer saccharinum l impacts of habitat specialization hybridization and glacial history
    Journal of Biogeography, 2011
    Co-Authors: Ikuyo Saeki, Burton V Barnes, Christopher W Dick, Noriaki Murakami

    Abstract:

    Aim  We analysed variation in chloroplast DNA (cpDNA) in red maple (Acer rubrum L.) and silver maple (Acer saccharinum L.) across a large part of their geographic ranges. Acer rubrum is one of the most common and morphologically variable deciduous trees of eastern North America, while its sister species A. saccharinum has a more restricted habitat distribution and displays markedly less morphological variation. Our objective was to infer the impact of biogeographic history on cpDNA diversity and phylogeographic structure in both species.

    Location  Deciduous forests of eastern North America.

    Methods  We sequenced 1289 to 1645 bp of non-coding cpDNA from A. rubrum (n = 258) and A. saccharinum (n = 83). Maximum parsimony networks and spatial analysis of molecular variance (SAMOVA) were used to analyse phylogeographic structure. Rarefaction analyses were used to compare genetic diversity.

    Results  A total of 40 cpDNA haplotypes were recovered from A. rubrum (38 haplotypes) and A. saccharinum (7 haplotypes). Five of the seven A. saccharinum haplotypes were shared with nearby samples of A. rubrum. SAMOVA recovered four phylogeographic groups for A. rubrum in: (1) south-eastern USA, (2) the Gulf and south-eastern Coastal Plain, (3) the lower Mississippi River Valley, and (4) the central and northern regions of eastern North America. Acer saccharinum had significantly lower haplotype diversity than A. rubrum, and novel haplotypes in post-glaciated northern limits of its range were shared with A. rubrum.

    Main conclusions  This is the first study of A. rubrum to report a distinct phylogeographic group centred on the lower Mississippi River, and the first to examine data comparatively with A. saccharinum. We hypothesized that A. rubrum would display stronger phylogeographic structure and greater haplotype diversity than A. saccharinum because of its greater geographic range, and ecological and morphological variation. This hypothesis was supported by the cpDNA analysis. The sharing of cpDNA and chloroplast simple sequence repeat (cpSSR) haplotypes in areas of geographic overlap provides evidence of introgression, which led to an increase in haplotype diversity in both species, and to novel phylogeographic structure in A. rubrum. We recommend that introgression be considered, along with other potential causes, as an explanation for the phylogeographic structure of cpDNA in plants.

Karlerik Eriksson – 3rd expert on this subject based on the ideXlab platform

  • laccase from sycamore maple Acer pseudoplatanus polymerizes monolignols
    Plant Physiology, 1992
    Co-Authors: Raja Sterjiades, Jeffrey F D Dean, Karlerik Eriksson

    Abstract:

    Current understanding of the final oxidative steps leading to lignin deposition in trees and other higher plants is limited with respect to what enzymes are involved, where they are localized, how they are transported, and what factors regulate them. With the use of cell suspension cultures of sycamore maple (Acer pseudoplatanus), an in-depth study of laccase, one of the oxidative enzymes possibly responsible for catalyzing the dehydrogenative polymerization of monolignols in the extracellular matrix, was undertaken. The time course for secretion of laccase into suspension culture medium was determined with respect to age and mass of the cells. Laccase was completely separated from peroxidase activity by hydrophobic interaction column chromatography, and its purity was assessed with different types of gel electrophoresis (isoelectric focusing-, native-, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis). Amino acid and glycosyl analyses of the purified enzyme were compared with those reported from previous studies of plant and fungal laccases. The specific activity of laccase toward several common substrates, including monolignols, was determined. Unlike a laccase purified from the Japanese lacquer tree (Rhus vernicifera), laccase from sycamore maple oxidized sinapyl, coniferyl, and p-coumaryl alcohols to form water-insoluble polymers (dehydrogenation polymers).