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Andrew J David - One of the best experts on this subject based on the ideXlab platform.
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proteomic comparison of needles from blister rust resistant and susceptible Pinus strobus seedlings reveals upregulation of putative disease resistance proteins
Molecular Plant-microbe Interactions, 2006Co-Authors: Jason A Smith, Robert A Blanchette, Todd A Burnes, James J Jacobs, Leeann Higgins, Bruce A Witthuhn, Andrew J David, Jeffrey H GillmanAbstract:In order to characterize a hypersensitive-like reaction in selected Pinus strobus seedlings to Cronartium ribicola, a proteomic comparison of needles from resistant and susceptible seedlings was undertaken using two-dimensional gel electrophoresis (2-DE). The results revealed 19 polypeptides specific to resistant seedlings and seven of these specific to infected resistant seedlings. There were 13 polypeptides up-regulated (≥3-fold increase) in resistant family P327 in comparison to needle tissue from susceptible and mock-inoculated seedlings. Electrospray ionization liquid chromatography and tandem mass spectrometry was used to sequence 11 proteins from the 2-DE gels. Sequences obtained from electrospray ionization liquid chromatography and tandem mass spectrometry were used for MSBLAST and Pro-ID database searches allowing identification with a 95 to 99% confidence level. Six proteins were determined to be homologs of proteins with known roles in disease resistance, five were determined to be homologs of members of the leucine-rich repeat (LRR) superfamily, and one was a homolog of heat shock protein 90, a protein that serves as a cofactor for certain LRR proteins. This is the first report of members of the LRR family with functional homologs in Pinus strobus and of a molecular basis for white pine blister rust resistance in Pinus strobus.
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epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine Pinus strobus
Phytopathology, 2006Co-Authors: Jason A Smith, Robert A Blanchette, Todd A Burnes, Jeffrey H Gillman, Andrew J DavidAbstract:Smith, J. A., Blanchette, R. A., Burnes, T. A., Gillman, J. H., and David, A. J. 2006. Epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine (Pinus strobus). Phytopathology 96:171-177. Epicuticular wax on needles was evaluated for its influence on Cronartium ribicola infection of resistant and susceptible selections of Pinus strobus. Environmental scanning electron microscopy comparisons revealed that needles from a resistant selection of eastern white pine, P327, had a significantly higher percentage of stomata that were occluded with wax, fewer basidiospores germinating at 48 h after inoculation, and fewer germ tubes penetrating stomata than needles from a susceptible selection H111. In addition, needles from seedlings that failed to develop symptoms 6 weeks after inoculation, from a cross between P327 and susceptible parent H109, had a significantly higher percentage of stomata occluded with wax compared with needles from seedlings that developed symptoms. In experiments where epicuticular waxes were removed from needles before seedlings were infected, resistant seedlings without wax developed approximately the same number of infection spots (as measured by spot index) as susceptible seedlings with wax intact. Gas chromatography/mass spectrometry comparisons of extracted epicuticular waxes revealed several peaks that were specific to P327 and not found in susceptible H111 suggesting biochemical differences in wax composition. These results implicate the role of epicuticular waxes as a resistance mechanism in P. strobus selection P327 and suggest a role for waxes in reducing spore germination and subsequent infection through stomatal openings.
Jason A Smith - One of the best experts on this subject based on the ideXlab platform.
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proteomic comparison of needles from blister rust resistant and susceptible Pinus strobus seedlings reveals upregulation of putative disease resistance proteins
Molecular Plant-microbe Interactions, 2006Co-Authors: Jason A Smith, Robert A Blanchette, Todd A Burnes, James J Jacobs, Leeann Higgins, Bruce A Witthuhn, Andrew J David, Jeffrey H GillmanAbstract:In order to characterize a hypersensitive-like reaction in selected Pinus strobus seedlings to Cronartium ribicola, a proteomic comparison of needles from resistant and susceptible seedlings was undertaken using two-dimensional gel electrophoresis (2-DE). The results revealed 19 polypeptides specific to resistant seedlings and seven of these specific to infected resistant seedlings. There were 13 polypeptides up-regulated (≥3-fold increase) in resistant family P327 in comparison to needle tissue from susceptible and mock-inoculated seedlings. Electrospray ionization liquid chromatography and tandem mass spectrometry was used to sequence 11 proteins from the 2-DE gels. Sequences obtained from electrospray ionization liquid chromatography and tandem mass spectrometry were used for MSBLAST and Pro-ID database searches allowing identification with a 95 to 99% confidence level. Six proteins were determined to be homologs of proteins with known roles in disease resistance, five were determined to be homologs of members of the leucine-rich repeat (LRR) superfamily, and one was a homolog of heat shock protein 90, a protein that serves as a cofactor for certain LRR proteins. This is the first report of members of the LRR family with functional homologs in Pinus strobus and of a molecular basis for white pine blister rust resistance in Pinus strobus.
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epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine Pinus strobus
Phytopathology, 2006Co-Authors: Jason A Smith, Robert A Blanchette, Todd A Burnes, Jeffrey H Gillman, Andrew J DavidAbstract:Smith, J. A., Blanchette, R. A., Burnes, T. A., Gillman, J. H., and David, A. J. 2006. Epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine (Pinus strobus). Phytopathology 96:171-177. Epicuticular wax on needles was evaluated for its influence on Cronartium ribicola infection of resistant and susceptible selections of Pinus strobus. Environmental scanning electron microscopy comparisons revealed that needles from a resistant selection of eastern white pine, P327, had a significantly higher percentage of stomata that were occluded with wax, fewer basidiospores germinating at 48 h after inoculation, and fewer germ tubes penetrating stomata than needles from a susceptible selection H111. In addition, needles from seedlings that failed to develop symptoms 6 weeks after inoculation, from a cross between P327 and susceptible parent H109, had a significantly higher percentage of stomata occluded with wax compared with needles from seedlings that developed symptoms. In experiments where epicuticular waxes were removed from needles before seedlings were infected, resistant seedlings without wax developed approximately the same number of infection spots (as measured by spot index) as susceptible seedlings with wax intact. Gas chromatography/mass spectrometry comparisons of extracted epicuticular waxes revealed several peaks that were specific to P327 and not found in susceptible H111 suggesting biochemical differences in wax composition. These results implicate the role of epicuticular waxes as a resistance mechanism in P. strobus selection P327 and suggest a role for waxes in reducing spore germination and subsequent infection through stomatal openings.
Krystyna Klimaszewska - One of the best experts on this subject based on the ideXlab platform.
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Optimized somatic embryogenesis in Pinus strobus L.
In Vitro Cellular & Developmental Biology - Plant, 2001Co-Authors: Krystyna Klimaszewska, Y. S. Park, Cathy Overton, Ian Maceacheron, J. M. BongaAbstract:Somatic embryogenesis (SE) initiation in Pinus strobus was optimized by the manipulation of plant growth regulator (PGR) concentrations in the culture medium. Modified Litvay medium (MLV) of Litvay et al. (1985) supplemented with lower than routinely used PGR concentration increased initiation of established embryogenic cultures from approximately 20 to 53%. The original developmental stage of zygotic embryos had a pronounced effect on the SE response. The optimum stage was the pre- to shortly post-cleavage stage. A substantial genetic influence on initiation of SE was indicated by a significant variance component due to families. Genotype X collection date and genotype X media interactions had large effects on initiation of SE. The PGR levels in the culture medium prior to maturation had a significant effect on subsequent production of mature somatic embryos. Embryogenic tissue initiated and proliferated on medium with a low level of PGR consistently produced a high number of somatic embryos, indicating that optimized initiation protocol also enhanced somatic embryo production. Somatic embryos of 93 embryogenic lines (representing five families) that were initiated on media with different PGR concentrations were converted to plants at an overall frequency of 76%, and grown in the greenhouse. With these improved protocols, application of P. strobus SE in commercial clonal forestry is feasible as an alternative to traditional breeding and reforestation.
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maturation of somatic embryos of Pinus strobus is promoted by a high concentration of gellan gum
Physiologia Plantarum, 1997Co-Authors: Krystyna Klimaszewska, Dale R SmithAbstract:Application of somatic embryogenesis to Pinus strobus clonal propagation and genetic improvement was hampered by the difficulty in achieving synchronous maturation of a large number of somatic embryos that would germinate and produce plants. Media containing abscisic acid (80 μM) and osmotic agents such as sucrose, polyethylene glycol and/or dextran did not sustain development of mature somatic embryos from plated embryonal masses. This indicated that factors other than osmotic agents might be involved in sustaining development of Pinus strobus somatic embryos to maturity. It was subsequently found that media lacking osmotica but containing a high concentration of gellan gum (1%) induced significant improvement in the development of mature somatic embryos in the presence of 80 or 120 μM abscisic acid. This positive effect was independent of the genotype and all four tested lines displayed similar responses. Media containing gellan gum at concentrations from 0.4 to 1.2% formed gels that varied in their strength. Gel strength was proportional to the concentration of gellan gum in the specific medium but varied depending on the medium formulation. Gel strength increased with the duration of storage of the culture medium by 46% (sD 14) after 14 days of storage. Preliminary results showed that embryos matured on high gellan gum media displayed improved germination frequencies. These results indicate that in Pinus strobus the water status and possibly other medium characteristics that are influenced by increased concentration of gelling agent have stimulatory effects on maturation of somatic embryos.
Jeffrey H Gillman - One of the best experts on this subject based on the ideXlab platform.
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proteomic comparison of needles from blister rust resistant and susceptible Pinus strobus seedlings reveals upregulation of putative disease resistance proteins
Molecular Plant-microbe Interactions, 2006Co-Authors: Jason A Smith, Robert A Blanchette, Todd A Burnes, James J Jacobs, Leeann Higgins, Bruce A Witthuhn, Andrew J David, Jeffrey H GillmanAbstract:In order to characterize a hypersensitive-like reaction in selected Pinus strobus seedlings to Cronartium ribicola, a proteomic comparison of needles from resistant and susceptible seedlings was undertaken using two-dimensional gel electrophoresis (2-DE). The results revealed 19 polypeptides specific to resistant seedlings and seven of these specific to infected resistant seedlings. There were 13 polypeptides up-regulated (≥3-fold increase) in resistant family P327 in comparison to needle tissue from susceptible and mock-inoculated seedlings. Electrospray ionization liquid chromatography and tandem mass spectrometry was used to sequence 11 proteins from the 2-DE gels. Sequences obtained from electrospray ionization liquid chromatography and tandem mass spectrometry were used for MSBLAST and Pro-ID database searches allowing identification with a 95 to 99% confidence level. Six proteins were determined to be homologs of proteins with known roles in disease resistance, five were determined to be homologs of members of the leucine-rich repeat (LRR) superfamily, and one was a homolog of heat shock protein 90, a protein that serves as a cofactor for certain LRR proteins. This is the first report of members of the LRR family with functional homologs in Pinus strobus and of a molecular basis for white pine blister rust resistance in Pinus strobus.
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epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine Pinus strobus
Phytopathology, 2006Co-Authors: Jason A Smith, Robert A Blanchette, Todd A Burnes, Jeffrey H Gillman, Andrew J DavidAbstract:Smith, J. A., Blanchette, R. A., Burnes, T. A., Gillman, J. H., and David, A. J. 2006. Epicuticular wax and white pine blister rust resistance in resistant and susceptible selections of eastern white pine (Pinus strobus). Phytopathology 96:171-177. Epicuticular wax on needles was evaluated for its influence on Cronartium ribicola infection of resistant and susceptible selections of Pinus strobus. Environmental scanning electron microscopy comparisons revealed that needles from a resistant selection of eastern white pine, P327, had a significantly higher percentage of stomata that were occluded with wax, fewer basidiospores germinating at 48 h after inoculation, and fewer germ tubes penetrating stomata than needles from a susceptible selection H111. In addition, needles from seedlings that failed to develop symptoms 6 weeks after inoculation, from a cross between P327 and susceptible parent H109, had a significantly higher percentage of stomata occluded with wax compared with needles from seedlings that developed symptoms. In experiments where epicuticular waxes were removed from needles before seedlings were infected, resistant seedlings without wax developed approximately the same number of infection spots (as measured by spot index) as susceptible seedlings with wax intact. Gas chromatography/mass spectrometry comparisons of extracted epicuticular waxes revealed several peaks that were specific to P327 and not found in susceptible H111 suggesting biochemical differences in wax composition. These results implicate the role of epicuticular waxes as a resistance mechanism in P. strobus selection P327 and suggest a role for waxes in reducing spore germination and subsequent infection through stomatal openings.
R. Larry Peterson - One of the best experts on this subject based on the ideXlab platform.
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Structural features of a Lophodermium endophyte during the cryptic life-cycle phase in the foliage of Pinus strobus
Mycological Research, 2001Co-Authors: Ron J. Deckert, L. H. Melville, R. Larry PetersonAbstract:Needles of Pinus strobus (white pine) were cleared and stained to survey the occurrence and location of Lophodermium sp., a fungal endophyte. Cytoplasmically dense endophytic hyphae with a pronounced lobed morphology and containing lipid bodies were localized intercellularly between the epidermis and hypodermis. These fungal infections did not appear quiescent, but rather exhibited signs of continual slow growth. A few associated host cells exhibited a hypersensitive response. Material embedded in resin and examined by light microscopy and transmission electron microscopy confirmed the location of hyphae between epidermal and hypodermal cells, and the presence of lipid bodies within the hyphae. In senescing needles, aggressive colonization of needle tissues occurred. Thus, for Lophodermium in white pine, endophytic infection is active rather than quiescent, and displays an alternate hyphal strategy to that seen in the reproductive phase.
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Epistomatal Chambers in the Needles of Pinus strobus L. (Eastern White Pine) Function as Microhabitat for Specialized Fungi
International Journal of Plant Sciences, 2001Co-Authors: Ron J. Deckert, L. H. Melville, R. Larry PetersonAbstract:The stomatal complex of eastern white pine (Pinus strobus L.) possesses a feature of uncertain function: the epistomatal chamber. The chambers are formed by the subsidiary cells that overarch the guard cells and are normally occluded with epicuticular wax. Morphologically distinct fungi resembling black yeasts are frequently observed within the epistomatal chambers submerged in the wax occlusions. Histochemistry shows that the fungal hyphae are viable and sheathed in a complex polysaccharide matrix. Experimental covering of the branches prevents colonization of the stomata, indicating that the inoculum originates exogenously. Preliminary investigations into the distribution of the fungus in Ontario, Canada, show an uneven distribution. Ecologically, the epistomatal chamber is proposed to be an ecotone between the phylloplane and the interior of the needle, one that possesses the survival advantages of both the phylloplane and the interior with few of the disadvantages associated with these two habitats. T...
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Distribution of foliar fungal endophytes of Pinus strobus between and within host trees
Canadian Journal of Forest Research, 2000Co-Authors: Ron J. Deckert, R. Larry PetersonAbstract:The distribution of foliar fungal endophytes within and between needles and trees of Pinus strobus L. (white pine) is largely unknown. In this study, needles were collected in Muskoka, Ontario, plated, and scored for hyphal outgrowth of endophytes to observe distributional patterns. Individual trees displayed different levels of infection but branches within those trees had similar levels. There was a large difference in the infection levels between the two extant needle age-classes, with the youngest needles being virtually endophyte-free. Needles divided into four sections exhibited the most hyphal outgrowth from the distal portion and the least from the medial-proximal portion. Cultural morphotypes were primarily of the Lophodermium and Hormonema morphologies. Lophodermium occurred at all positions along the needle but Hormonema was restricted to the proximal and distal portions. Infrequently occurring fungi of diverse morphotypes were found at all four needle positions. A separate experiment compared levels of endophyte infection between Muskoka trees and trees growing in an urban area (Guelph, Ontario). Needle pieces from Guelph hosts had low rates of infection (0.02%) compared with needle pieces from Muskoka hosts (66.5%). Thus, for white pine, foliar endophyte distribution is patchy within and between needles, trees, and locations, possibly reflecting differences in microhabitat or infection success.
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Distribution of foliar fungal endophytes of Pinus strobus between and within host trees.
Canadian Journal of Forest Research, 2000Co-Authors: Ron J. Deckert, R. Larry PetersonAbstract:The distribution of foliar fungal endophytes within and between needles and trees of Pinus strobus L. (white pine) is largely unknown. In this study, needles were collected in Muskoka, Ontario, pla...
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Morphological and anatomical characterization of ectomycorrhizas and ectendomycorrhizas on Pinus strobus seedlings in a southern Ontario nursery
Canadian Journal of Botany, 1997Co-Authors: Margot Ursic, R. Larry PetersonAbstract:A morphological and anatomical study of the mycorrhizas on Pinus strobus L. was conducted on seedlings excavated from St.-Williams nursery in southern Ontario. Micro- and macro-scopic characters were used to classify the morphotypes into complexes and, when possible, genera and species. An E-strain fungus, fungi from the Mycelium radicis atrovirens (MRA) complex, and an unidentified ascomycetous "red-type" fungus formed ectendomycorrhizal (EECM) associations, while Tuber sp., Hebeloma sp., and Thelephora terrestris formed ectomycorrhizal (ECM) associations in the nursery. Cultures of Hebeloma sp., the E-strain fungus, Tuber sp., and two morphologically distinct MRA fungi (MRA1, later identified as Phialophora finlandia Wang & Wilcox, and MRA2, unidentified) were isolated from field-collected morphotypes and re-inoculated onto Pinus strobus seedlings grown in semisterile pot cultures for 4 months. In the resynthesis experiment, the E-strain fungus formed EECM with sparse intracellular colonization, and Tub...