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J. A. Menge - One of the best experts on this subject based on the ideXlab platform.
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repetitive applications of the biocontrol agent pseudomonas putida 06909 rif nal and effects on populations of Phytophthora Parasitica in citrus orchards
Phytopathology, 2002Co-Authors: K. Steddom, O. Becker, J. A. MengeAbstract:ABSTRACT Pseudomonas putida 06909-rif/nal was applied repetitively during the irrigation season in two citrus orchards over 3 years. In a mature (50-yearold) commercial citrus orchard covering 2.02 ha, weekly applications of Pseudomonas putida 06909-rif/nal with an in-field fermentor resulted in soil populations that fluctuated between 2.83 log CFU + 1 per g of soil and 4.35 log CFU + 1 per g of soil. Resulting rhizosphere populations of Phytophthora Parasitica were significantly reduced in 1999 but not 1997 or 1998. In a newly planted citrus orchard, yearly applications of Pseudomonas putida 06909-rif/nal at the beginning of the irrigation season resulted in high soil populations of Pseudomonas putida 06909-rif/nal that declined rapidly and never reduced the rhizosphere populations of Phytophthora Parasitica. When Pseudomonas putida 06909-rif/nal was applied weekly, soil populations increased throughout the 1997 and 1998 irrigation seasons, reaching a maximum in 1998 and remained high throughout the 1999...
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Repetitive Applications of the Biocontrol Agent Pseudomonas putida 06909-rif/nal and Effects on Populations of Phytophthora Parasitica in Citrus Orchards.
Phytopathology, 2002Co-Authors: K. Steddom, O. Becker, J. A. MengeAbstract:ABSTRACT Pseudomonas putida 06909-rif/nal was applied repetitively during the irrigation season in two citrus orchards over 3 years. In a mature (50-yearold) commercial citrus orchard covering 2.02 ha, weekly applications of Pseudomonas putida 06909-rif/nal with an in-field fermentor resulted in soil populations that fluctuated between 2.83 log CFU + 1 per g of soil and 4.35 log CFU + 1 per g of soil. Resulting rhizosphere populations of Phytophthora Parasitica were significantly reduced in 1999 but not 1997 or 1998. In a newly planted citrus orchard, yearly applications of Pseudomonas putida 06909-rif/nal at the beginning of the irrigation season resulted in high soil populations of Pseudomonas putida 06909-rif/nal that declined rapidly and never reduced the rhizosphere populations of Phytophthora Parasitica. When Pseudomonas putida 06909-rif/nal was applied weekly, soil populations increased throughout the 1997 and 1998 irrigation seasons, reaching a maximum in 1998 and remained high throughout the 1999...
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Population fluctuations and the numbers and types of propagules of Phytophthora Parasitica that occur in irrigated citrus groves
Plant Disease, 1991Co-Authors: A. L. Lutz, J. A. MengeAbstract:Citrus trees were irrigated via furrows or low-volume emitters, and populations of Phytophthora Parasitica from the rhizosphere were monitored over a period of 12 days after irrigation by soil dilution plate assay on a selective medium. The types of propagules present under long- and short-interval irrigation regimes were quantified from November through August. Populations of P. Parasitica increased from 17 propagules per gram (ppg) the day before irrigation to 70 ppg 2 days after long-interval furrow irrigation. Populations ranged from 71 to 93 ppg with short-interval drip irrigation (.)
H. D. Shew - One of the best experts on this subject based on the ideXlab platform.
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Managing the Race Structure of Phytophthora Parasitica var. nicotianae with Cultivar Rotation
Plant disease, 2005Co-Authors: M. J. Sullivan, T. A. Melton, H. D. ShewAbstract:Sullivan, M. J., Melton, T. A., and Shew, H. D. 2005. Managing the race structure of Phytophthora Parasitica var. nicotianae with cultivar rotation. Plant Dis. 89:1285-1294. Deployment of tobacco cultivars with single-gene, complete resistance to race 0 of the tobacco black shank pathogen, Phytophthora Parasitica var. nicotianae, has resulted in a rapid increase in the occurrence of race 1 of the pathogen in North Carolina. Cultivar-rotation studies were conducted in three fields to assess how different levels and types of resistance affected the race structure and population dynamics of the pathogen when deployed in fields initially containing single or mixed races of the pathogen. In a field with both races present, a high level of partial resistance in cv. K 346 was most effective in reducing disease and decreasing the proportion of race 1 in the pathogen population. The deployment of complete resistance in cv. NC 71 resulted in intermediate levels of disease control and race 1 became the predominate race. The cv. K 326, with a low level of partial resistance, had the highest levels of disease, and race 0 was the dominant race recovered. In a field where no race 1 was detected initially, disease incidence was high with the use of partial resistance. Complete resistance was very effective in suppressing disease, but race 1 was recovered after only one growing season. By the end of the third growing season, race 1 was recovered from most treatments where single-gene resistance was deployed. A high level of partial resistance was most effective in suppressing disease in a field where race 1 initially was the predominant race. A rotation between cultivars with single-gene resistance and cultivars with a high level of partial resistance should provide the most effective approach to black shank management. This rotation will reduce disease incidence and minimize race shifts in the pathogen and, over time, should prolong the usefulness of the Ph gene for black shank control in commercial production of tobacco. Additional keywords: Fla. 301 Nicotiana tabacum
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Fitness of Races 0 and 1 of Phytophthora Parasitica var. nicotianae.
Plant disease, 2005Co-Authors: M. J. Sullivan, T. A. Melton, H. D. ShewAbstract:Sullivan, M. J., Melton, T. A., and Shew, H. D. 2005. Fitness of races 0 and 1 of Phytophthora Parasitica var. nicotianae. Plant Dis. 89:1220-1228. Deployment of tobacco (Nicotiana tabacum) varieties with complete resistance to race 0 of Phytophthora Parasitica var. nicotianae has led to a rapid increase in the field populations of race 1 in North Carolina. In a field study, population levels of race 1 decreased relative to race 0 when cultivars with partial resistance to both races were planted, suggesting that race 1 isolates were less fit than race 0 isolates. Experiments were conducted to quantify differences in aggressiveness and survivability of the two races. Tobacco varieties with low, moderate, or high levels of partial resistance were inoculated with 60 pathogen isolates, and symptom development was monitored for 3 weeks. Race 0 isolates were more aggressive than race 1 isolates on cultivars with moderate or high levels of partial resistance; incubation periods were shorter and root rot severity was greater with race 0 isolates. Isolates of race 1, however, caused greater stunting of plants with moderate and high levels of partial resistance than race 0 isolates. Field microplots were infested with either a single race or an equal mixture of each race. Soil samples were collected at the end of two growing seasons and again the following spring. Pathogen populations declined from 40 to 80% during winter months, but population declines for race 0 were lower than for race 1 in each treatment over each winter. Race shifts from race 1 to race 0 that were observed in the presence of cultivars with partial resistance appear to be primarily the result of differences in aggressiveness of the races, with a possible minor effect of enhanced overwintering survival of race 0 compared with race 1.
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Nonphytotoxic Aluminum-Peat Complexes Suppress Phytophthora Parasitica.
Phytopathology, 2001Co-Authors: E. J. Fichtner, Dean Hesterberg, H. D. ShewAbstract:ABSTRACT Amendment of peat-based potting media with Al2(SO4)3 suppresses damping-off of Vinca (Catharanthus roseus) caused by Phytophthora Parasitica. The species of aluminum (Al) responsible for disease suppression have not been identified. The objective of this study was to determine the effects of amount and pH of Al2(SO4)3 amendment solutions on survival of P. Parasitica. In separate experiments, peat was amended with Al2(SO4)3 solutions adjusted to pH 4 or 6 at either 0.0158 or 0.0079 g of Al per gram of peat. Amended peat was placed in Buchner funnels maintained at -2.5 kPa matric potential. Peat was infested with P. Parasitica by placing zero, two, or five colonized Vinca leaf disks in each funnel, and 15 Vinca seeds were placed in each funnel. After 24 h, the matric potential was brought to 0 kPa to induce zoospore release and returned to -2.5 kPa after 24 h. Pathogen populations and stand counts were assessed after 2-week incubation. Al amendment solutions at both pH 4 and 6 reduced pathogen popu...
Benoit Industri - One of the best experts on this subject based on the ideXlab platform.
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characterization of ppmucl1 2 3 three members of a new oomycete specific mucin like protein family residing in Phytophthora Parasitica biofilm
Protist, 2014Co-Authors: Marie Larousse, Benjamin Govetto, Aurelie Seassau, Catherine Etienne, Benoit IndustriAbstract:The plant pathogen Phytophthora Parasitica forms a biofilm on the host surface. The biofilm transcriptome is characterized by the expression of PPMUCL1/2/3 (Phytophthora Parasitica MUCIN-LIKE) genes, which we report here to be members of a new, large mucin-like gene family restricted to the oomycete lineage. These genes encode secreted proteins organized into two domains. The NH2-terminal domain is highly conserved, but of unknown function. The second domain is a mucin-like domain enriched in threonine and serine residues, with a large number of putative O-glycosylation sites and a repeated motif defining 15 subgroups among the 315 members of the family. The second domain was found to be glycosylated in the recombinant rPPMUCL1 and rPPMUCL2 proteins. An analysis of PPMUCL1/2/3 gene expression indicated that these genes were expressed in a specific and coordinated manner in the biofilm. A novel cis-motif (R) bound to nuclear proteins, suggesting a possible role in PPMUCL1/2/3 gene regulation. Immunohistochemical staining revealed that the PPMUCL1/2 proteins were secreted and accumulated on the surface of the biofilm. Our data demonstrate that PPMUCL1/2/3 belong to a new oomycete-specific family of mucin-like proteins playing a structural role in the biofilm extracellular matrix.
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Characterization of PPMUCL1/2/3, Three Members of a New Oomycete-specific Mucin-like Protein Family Residing in Phytophthora Parasitica Biofilm
Protist, 2014Co-Authors: Marie Larousse, Michel Ponchet, Franck Panabières, Emeline Deleury, Benjamin Govetto, Aurelie Seassau, Catherine Etienne, Benoit Industri, Nicolas Theodorakopoulos, Eric GalianaAbstract:The plant pathogen Phytophthora Parasitica forms a biofilm on the host surface. The biofilm transcriptome is characterized by the expression of PPMUCL1/2/3 (Phytophthora Parasitica MUCIN-LIKE) genes, which we report here to be members of a new, large mucin-like gene family restricted to the oomycete lineage. These genes encode secreted proteins organized into two domains. The NH2-terminal domain is highly conserved, but of unknown function. The second domain is a mucin-like domain enriched in threonine and serine residues, with a large number of putative O-glycosylation sites and a repeated motif defining 15 subgroups among the 315 members of the family. The second domain was found to be glycosylated in the recombinant rPPMUCL1 and rPPMUCL2 proteins. An analysis of PPMUCL1/2/3 gene expression indicated that these genes were expressed in a specific and coordinated manner in the biofilm. A novel cis-motif (R) bound to nuclear proteins, suggesting a possible role in PPMUCL1/2/3 gene regulation. Immunohistochemical staining revealed that the PPMUCL1/2 proteins were secreted and accumulated on the surface of the biofilm. Our data demonstrate that PPMUCL1/2/3 belong to a new oomycete-specific family of mucin-like proteins playing a structural role in the biofilm extracellular matrix.
Eric Galiana - One of the best experts on this subject based on the ideXlab platform.
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Characterization of PPMUCL1/2/3, Three Members of a New Oomycete-specific Mucin-like Protein Family Residing in Phytophthora Parasitica Biofilm
Protist, 2014Co-Authors: Marie Larousse, Michel Ponchet, Franck Panabières, Emeline Deleury, Benjamin Govetto, Aurelie Seassau, Catherine Etienne, Benoit Industri, Nicolas Theodorakopoulos, Eric GalianaAbstract:The plant pathogen Phytophthora Parasitica forms a biofilm on the host surface. The biofilm transcriptome is characterized by the expression of PPMUCL1/2/3 (Phytophthora Parasitica MUCIN-LIKE) genes, which we report here to be members of a new, large mucin-like gene family restricted to the oomycete lineage. These genes encode secreted proteins organized into two domains. The NH2-terminal domain is highly conserved, but of unknown function. The second domain is a mucin-like domain enriched in threonine and serine residues, with a large number of putative O-glycosylation sites and a repeated motif defining 15 subgroups among the 315 members of the family. The second domain was found to be glycosylated in the recombinant rPPMUCL1 and rPPMUCL2 proteins. An analysis of PPMUCL1/2/3 gene expression indicated that these genes were expressed in a specific and coordinated manner in the biofilm. A novel cis-motif (R) bound to nuclear proteins, suggesting a possible role in PPMUCL1/2/3 gene regulation. Immunohistochemical staining revealed that the PPMUCL1/2 proteins were secreted and accumulated on the surface of the biofilm. Our data demonstrate that PPMUCL1/2/3 belong to a new oomycete-specific family of mucin-like proteins playing a structural role in the biofilm extracellular matrix.
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Plant-induced cell death in the oomycete pathogen Phytophthora Parasitica.
Cellular microbiology, 2005Co-Authors: Eric Galiana, Marie-pierre Rivière, Sophie Pagnotta, Emmanuel Baudouin, Franck Panabières, Pierre Gounon, Laure BoudierAbstract:Summary The activation of programmed cell death in the host during plant–pathogen interactions is an important component of the plant disease resistance mechanism. In this study we show that activation of programmed cell death in microorganisms also regulates plant–pathogen interactions. We found that a form of vacuolar cell death is induced in the oomycete Phytophthora Parasitica– the agent that causes black shank disease in Nicotiana tabacum– by extracellular stimuli from resistant tobacco. The single-celled zoospores underwent cell death characterized by dynamic membrane rearrangements, cell shrinkage, formation of numerous large vacuoles in the cytoplasm and degradation of cytoplasmic components before plasma membrane disruption. Phytophthora cell death required protein synthesis but not caspase activation, and was associated with the production of intracellular reactive oxygen species. This characterization of plant-mediated cell death signalling in pathogens will enhance our understanding of the biological processes regulating plant–pathogen interactions, and improve our ability to control crop diseases.
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gene identification in the oomycete pathogen Phytophthora Parasitica during in vitro vegetative growth through expressed sequence tags
Fungal Genetics and Biology, 2005Co-Authors: Franck Panabières, Eric Galiana, Joelle Amselem, Joyanne Le BerreAbstract:Phytophthora Parasitica is a soilborne oomycete pathogen capable of infecting a wide range of plants, including many solanaceous plants. In a first step towards large-scale gene discovery, we generated expressed sequence tags (ESTs) from a cDNA library constructed using mycelium grown in synthetic medium. A total of 3568 ESTs were assembled into 2269 contiguous sequences. Functional categorization could be performed for 65.45% of ESTs. A significant portion of the transcripts encodes proteins of common metabolic pathways. The most prominent sequences correspond to members of the elicitin family, and enzymes involved in the lipid metabolism. A number of genes potentially involved in pathogenesis were also identified, which may constitute virulence determinants.
Marie Larousse - One of the best experts on this subject based on the ideXlab platform.
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characterization of ppmucl1 2 3 three members of a new oomycete specific mucin like protein family residing in Phytophthora Parasitica biofilm
Protist, 2014Co-Authors: Marie Larousse, Benjamin Govetto, Aurelie Seassau, Catherine Etienne, Benoit IndustriAbstract:The plant pathogen Phytophthora Parasitica forms a biofilm on the host surface. The biofilm transcriptome is characterized by the expression of PPMUCL1/2/3 (Phytophthora Parasitica MUCIN-LIKE) genes, which we report here to be members of a new, large mucin-like gene family restricted to the oomycete lineage. These genes encode secreted proteins organized into two domains. The NH2-terminal domain is highly conserved, but of unknown function. The second domain is a mucin-like domain enriched in threonine and serine residues, with a large number of putative O-glycosylation sites and a repeated motif defining 15 subgroups among the 315 members of the family. The second domain was found to be glycosylated in the recombinant rPPMUCL1 and rPPMUCL2 proteins. An analysis of PPMUCL1/2/3 gene expression indicated that these genes were expressed in a specific and coordinated manner in the biofilm. A novel cis-motif (R) bound to nuclear proteins, suggesting a possible role in PPMUCL1/2/3 gene regulation. Immunohistochemical staining revealed that the PPMUCL1/2 proteins were secreted and accumulated on the surface of the biofilm. Our data demonstrate that PPMUCL1/2/3 belong to a new oomycete-specific family of mucin-like proteins playing a structural role in the biofilm extracellular matrix.
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Characterization of PPMUCL1/2/3, Three Members of a New Oomycete-specific Mucin-like Protein Family Residing in Phytophthora Parasitica Biofilm
Protist, 2014Co-Authors: Marie Larousse, Michel Ponchet, Franck Panabières, Emeline Deleury, Benjamin Govetto, Aurelie Seassau, Catherine Etienne, Benoit Industri, Nicolas Theodorakopoulos, Eric GalianaAbstract:The plant pathogen Phytophthora Parasitica forms a biofilm on the host surface. The biofilm transcriptome is characterized by the expression of PPMUCL1/2/3 (Phytophthora Parasitica MUCIN-LIKE) genes, which we report here to be members of a new, large mucin-like gene family restricted to the oomycete lineage. These genes encode secreted proteins organized into two domains. The NH2-terminal domain is highly conserved, but of unknown function. The second domain is a mucin-like domain enriched in threonine and serine residues, with a large number of putative O-glycosylation sites and a repeated motif defining 15 subgroups among the 315 members of the family. The second domain was found to be glycosylated in the recombinant rPPMUCL1 and rPPMUCL2 proteins. An analysis of PPMUCL1/2/3 gene expression indicated that these genes were expressed in a specific and coordinated manner in the biofilm. A novel cis-motif (R) bound to nuclear proteins, suggesting a possible role in PPMUCL1/2/3 gene regulation. Immunohistochemical staining revealed that the PPMUCL1/2 proteins were secreted and accumulated on the surface of the biofilm. Our data demonstrate that PPMUCL1/2/3 belong to a new oomycete-specific family of mucin-like proteins playing a structural role in the biofilm extracellular matrix.